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Home My WebLink About20230098.tiff1 PAGE OF DOCUMENT INCLUDED IN PAPER FILE. 8120 Gage Street • Frederick, CO 80516 Bus: (303) 666-6657 • Fax: (303) 666-6743 REMAINDER RETAINED ELECTRONICALLY IN TYLER. January 4, 2023 Weld County Clerk to the Board 1150 O Street Greeley, CO 80631 Subject: Raptor Materials LLC Two Rivers Sand, Gravel and Reservoir Project - permit # M-2022-013 — Second Adequacy Response Attachments: Second Adequacy Letter Second Adequacy Response Cover Letter Second Adequacy Response to DRMS Updated 112 Form Updated Exhibit D — Extraction Plan Updated Exhibit E — Reclamation Plan Updated Exhibit G — Water Information Updated Exhibit I/J — Soils Information Updated Exhibit L— Reclamation Costs Updated Exhibit M — Other Permits and Licenses Updated Exhibit O — Owners of Record of Affected Land and Owners of Substance to be Mined Updated Exhibit S — Permanent Man-made Structures Addenda Updated Exhibit C1 Map — Existing Conditions Updated Exhibit C2 Map — Extraction Plan Updated Exhibit F Map — Reclamation Plan Updated Exhibit G Map — Water Information Updated Exhibit In Map — Soils and Vegetation Updated Exhibit L Map - Financial Warranty Pu 6) ; G tie v;e („) °I/IC/23 CC : PL (TP/K14/Da/x0/DR), PW (cH/ER/cx) of/lo/23 2023-0098 Your signature below acknowledges receipt of the above referenced materials, as attached. The materials should be added to the above referenced Application, as originally submitted to the Weld County Clerk to the Board, and made accessible for public review. Received On , 2023 By: Office of the Weld County Clerk to the Board of County Commissioners RECEIVED JAN 0 4 2023 WELD COUNTY COMMISSIONERS Raptor Materials, LLC. 8120 Cade Street Frederick, CO 80516 Telephone.(3o3) 666-6657 Fax (303) 666-6743 Wednesday 04 January 2023 T o. From: Subject: Dear Rob. Robert D. Zuber, P.E. Environmental Protection Specialist Colorado Division of Reclamation Mining and Safety Office of Mined Land Reclamation (OMLR) 1313 Sherman Street, Room 215 Denver, Colorado 80203 Garrett C. Varra, General Manager Two Rivers Sand, Gravel and Reservoir Project, File No. M-2022-013, 112c Permit Application Adequacy Review #2 - REPLY The Division of Reclamation, Mining and Safety (Division/DRMS), Office of Mined Land Reclamation COMLR): reviewed the contents of the Original 112c permit application for the Two Rivers Sand, Gravel and Reservoir Project (TRP), File No. M-2022-013 and submitted comments. Raptor responded to the First Adequacy comments on September 06, 2022 and the Division responded with additional comments in a Second Adequacy Review dated October 17, 2022 and subsequently with additional comments on November 17, 2022. The Division was required to issue an approval or denial decision to the original application no later than July 17, 2022. Several extensions have been requested and granted through the review and response process with the current extension through January 06, 2023. The review consisted of comparing the application contents with the specific requirements of Rules 1, 3, 6.1, 6.2, 6.4 and 6.5 of the Minerals Rules and Regulations of the Colorado Mined Land Reclamation Board for the Extraction of Construction Materials (effective date July 15, 2019). Any inadequacies were identified under respective exhibit headings, along with suggested actions to correct them. We have reviewed the Division's comments and trust the following reply will serve to fully address them. For greater continuity and ease of reference, we have iterated the comments from the OMLR Adequacy Review (Review) of 24 June 2022 and 05 August Pa.ii e 1 2022, necessitating a reply according to its respective item numbers from the Review, iterated in a graphical box, with our comments in blue following: Prologue Thu permit application has been prepared as a holistic document. We believe it would be inconsistent with the intent of the Rules and Regulations or good practice to approach it otherwise. Mining must be designed from the outset and operated through the life of the mine with closure in mind. To different degrees then, all the elements of the application are interwoven and form a narrative about the development, operation and ultimately closure of the mine. Naturally the Rules and Regulations must be segmented to at least address different elements of this process, but where the context of a discussion suggests certain discussions be combined, we have done this. There comes a point when the review will so put into fractions for purposes of style as to make the application fundamentally difficult to navigate or perform as a useful tool for compliance by the Operator. To cross reference every subject or element of the application would make the document both unwieldy and likely harder to understand and comprehend, rendering it less likely to be useful to either the operator or regulator. For example, while some information in Exhibits D and E addresses soils and vegetation, there is another exhibit completely devoted to the same. Similarly, there are independent exhibits intended to satisfy parts of Exhibit H - Wildlife Information, which may also add to the understanding of I/J - Soils and vegetation and other data. Soils and Vegetation are grouped because they are so contextually close and difficult to regard separately, so keen are their influences. This is not new and is also consistent with how we access established information of the same from SCS (MRCS) reports and data, as provided under Exhibit Soils and Vegetation Information, and maps. The vegetation, being typified according to soils, shown on the maps, fully complies with a map -based description of vegetation as it may naturally occur absent man caused modifications like agriculture or natural events like flooding or wildlife impacts, clearly evident in the aerial photographs used to enhance maps. Consequently, there are extensive references to Exhibit ILI throughout this application, in large part because soils are so integral to every aspect of the project, and it would be ungainly to repeatedly end every paragraph touching on the subject in Exhibits D, E, or others with redundant references. The same logic applies to Exhibit G: Water Information, which may also have other 2 i Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand. Gravel and Reservoir Project — M2022-013. supplemental water information contextually placed in other exhibits. An effort is made to call out these respective exhibits where the information desired in one exhibit is found in another, or as it may be otherwise be identified by a map legend. With regard to map exhibits, please consider the aerial information at scale is intended to speak pictorially and provide substantial detail. Typically maps includes additional information to aid clarity, even though such information is not necessarily called outby the Rules and Regulations. This serves to minimize extensive additional narrative. since a picture (commonly) really is worth a thousand words. It should be considered that the Rules and Regulations call for a considerable amount of information thatmust appear on the included maps. Some discretion as to what is revealed and how on a given map exhibit is in part determined in the submittal to meet. the demands of communicating to a broad audience. Some information that might appear or notappear on a given map are commonly represented on another for the sake of context with the associated narrative under the same or similar intent. We are aware of the present-day names and full anacronyrns of governmental agencies referenced in this submittal. It is a matter of convention versus free expression as a reasonable person might view it. Clearly, the Agency comments suggest it understands the application of the names and letters that we used. In other cases, we are unclear on apparent conflicts with the Rules and Regulations. • OMILR (it has been suggested we remove this acronym as it does not exist): It's in your Definitions: Rule 1.1 (32) (32) "Office" means the office of Mined Land Reclamation within the Division of Reclamation, Mining and Safety (DRMS). it's in your Rules and Regulations: Any reference to the Colorado Office of Mined Land Reclamation is consistent with the following Colorado Revised Statutes, as of year 2020 (Source: Justia > US Law > US Codes and Statutes > Colorado Revised statutes > 2020 Colorado Revised Statutes > Title 34 - Mineral Resources > Article 32. Colorado Mined Land Reclamation Act 3 Section 34-32-105. Office of mined land reclamation - mined land reclamation board created. 3 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob tuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Universal Citation: CO Rev Stat 34-32-105 (2020 (6)There is hereby created, in the division of reclamation, mining, any- safety in the department of natural resources, the o ffice of mined land reclamation and, in the department of n atural resources, the mined land reclamation board. The head o f the office of mined land reclamation shall be appointed by the director. The head of the office of mined land reclamation shall have professional and supervisory experience in mined land reclamation, mining, or natural resource planning and management. • Change "NPDES" to "CDPS" to reflect the requirements of the Water Quality Control Commission. Our only reference to NPDES was simply incorporating the following text directly from the rules. Rule 6.4.7 (5) (5) The Operator/Applicant shall affirmatively state that the Operator/ pbcant has acquired (or has apps for) a National Pollutant Discharge Eliminaton System permit from the Water Quality Control Division at the Colorado Department 0 Health and Environment, if necessary. Also, any effort to update agency names betrays our desire under the First Amendment to maintain a casual reference in place of convention, which is apparently easy enough to follow, and has been since 1999. For example: • We use DOW in reference to the Colorado Division of Parks and Wildlife, but left out Parks - because wildlife is involved, but not parks. We are aware of their formal name and alphabet soup. • For the Colorado Division of Water Resources, we may use DWR or OSE— for the office of the State Engineer, or some, SRO for State kngineer's office, which resides within the Division. Om- abbreviations occur in parenthesis at least once in reference to their full expansion. In future submittals, we will make efforts to bring some of these forward as desired, but for consistency and to avoid possible confusion in the many documents making up this application and in keeping with convention accepted in our submittals since 1999, it is preferred to maintain the current acronyms. October 17, 2022 Second Adequacy Review - General Comments 1) on May 18, 2022, the Division approved a transfer of the Two Rivers Sand, Gravel 4IPaue Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. and Reservoir Project 112 Application from Varra Companies, Inc. to Raptor Materials, LLC. Please provide a letter from Kevin Jeakins (as part of your response to this adequacy review) stating that Bradford Janes is authorized to act as a permitting representative of Raptor Materials L.LC. Raptor Materials First Adequacy Response The work and prior submittals of Rradford Janes, a Professional Forester and Soil Scientist, having nearly 43 -years of experience in orchestrating the diverse talents and content that comprise Minerals Section permits of the Colorado Division of Reclamation Mining and Safety's (DRMS), Office of Mined. Land Reclamation COMLFU, is presently employed by. Raptor Materials, LLC. (RM). All submittals through our Office of Special Projects represented essential continuity from his work under the same with Varra Companies, Inc. His work continues, now under the direct responsibility, oversight and approval of my Office, as signified below; and continuing under Garrett C. Varra, General Manager and former President of Varra Companies, Inc.: all under the authority of Raptor Materials, LLC. Please NOTE.; Since the Application began under Varra Companies, inc., a Succession of Operator to Raptor Materials, LLC has since been approved by the OILR. Garrett C. Varra is now our new Permittee Contact and Designated Representative, until and unless otherwise notified. , 2022 Kevin Jeakins, Vice -President Raptor Materials, LLC. Division Second Adequacy Comment No additional response is required from £11. 2) Please commit to submitting Financial and Performance Warranties with the name Raptor Materials, LLC. Raptor Materials First Adequacy Response 5IPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. All financial and performance warranties necessary for the issuance of an approved OMLR Permit will be submitted, as underwritten by or for, Raptor Materials, LLC. Division Second Adequacy Comment No additional tional response is required "ed from RM. 3) The Division received timely state agency comments from History Colorado and the Division of Water Resources, as well as a late comment letter from Colorado Parks and Wildlife. The letters from these agencies are included as an enclosure with this adequacy review letter. Please review the letters and provide comments accordingly. Raptor Materials First Adequacy Response The comments from History Colorado are acknowledged. RM intends to complete a Class III Intensive Cultural Resource Inventory of the permitted area. Concerning comments from the Division of Water Resources, RM has affirmed in Item 54 of this response that all permits including well permits and documents related to water rights, such as a Substitute Water Supply Plan will be obtained and provided before actions requiring permits commence. A revised application for CDPS General Permit COG500000 Discharges from Sand and Gravel Mining and Processing is submitted with this response. Comments from Colorado Parks and Wildlife are addressed in various comments throughout this response and in the response prepared by ERO dated August 26, 2022 attached as an addendum to Exhibit H. Division Second Adequacy Comment No additional response is requfred from Rll,l. Application Form 4) The application form must be updated to indicate that the new perrn.ittee is Raptor Materials LLC. Raptor Materials First Adequacy Response An updated and signed, Regular Impact (112) Construction Materials application form under Raptor Materials, LLC., is attached. Wage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuher, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project — M2022-013. Division Second Adequacy Comment No additional response is required from RAI 5) on Page 1, Item 111.1 of the application form, the Applicant indicated the type of organization as a corporation. Please provide the corporation seal on Page 8 of the application form, if the corporation does not have a seal please indicate "no seal", Raptor Materials First Adequacy Response Raptor Materials, LLC., is a Limited Liability Company and does not have a Corporate Seal. Consistent with Item #1, above, a newly completed 112 Construction Materials Application is provided as requested and having the signature of the vice -President of Operations. Division Second Adequacy Comment Please revise Page of the form and add the taut "no seal.". Raptor Materials Second Adequacy Response The application has been revised as requested. 6.2 General Requirements of Exhibits 6) Rule 6.2.1(2)(b) requires maps be signed by a registered land surveyor, professional engineer, or other qualified person. Please submit signed copies of the Rxhihit C and Exhibit F maps Raptor Materials First Adequacy Response All maps for Permit M2022-013, were submitted Digitally. All maps show they were `Drawn by: B. L. Janes.There is no reliable way to insert a legitimate signature on the maps. Please allow this reply to serve as testimony and signatory that all maps previously created in cooperation with diverse content providers and technical support, with Autodesk software and utilized by the Office of Special Projects, from which the final drawing was created by B.L. Janes. The content includes survey and aerial data for optimum accuracy and portrayal of all features and content to scale; including area roads, vegetation, and other obvious features as apparent or otherwise identified there -in, such as internal irrigation ditch -works all owned by 7 Page Correspondence to the Colorado Otlice of Mined Land Reclamation — Reply to Rob Zuber, EPS Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Raptor Materials, LLC. This Signature, below, bears witness to this effect that all maps as submitted prior to this date were digital reproductions on .pdf and in this instance were Drawn By: H.L. Janes. , 2022 B.L. Janes PLEASE NOTE: Future Map Submittals beyond those already provided with the Original Application, or under this Adequacy Reply, will come with separate letterhead bearing this OR a similar Affirmation relative to the assigned Cartographer, and Original (not facsimile) Signature in Blue Ink as Drawn By; will apply equally to ALL as Signified, Signed and Dated, as provided with that submittal. 2022 Kevin Jeakins, Vice -President Raptor Materials, LLC. Division Second Adequacy Comment ft is OO177171O17 practice for operators to provide signed maps. R41 needs to compl v 1 t-ith this request-. Raptor Materials Second Adequacy Response All maps have been updated and are signed as requested. 6.4 Specific Exhibit Requirements - Regular 112 Operations The following items must be addressed by the Applicant to satisfy the Mineral Rules and Regulations of the Mined Land Reclamation Board: 6.4.1 Exhibit A - Legal Description 7) The Applicant indicated that a portion of the permit area is in Sections 3 and 4 of Township 4 North, Range 65 West. However, it appears (based on the Exhibit Map in Exhibit B) that the text should indicate Range 66 West instead of 65 west. Please address this apparent error and revise the Exhibit A text as necessary. 8 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Luber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Raptor Materials First Adequacy Response Exhibit A has been updated to reflect the correction, as attached. Division Second Adequacy Comment _Vb additional response is required from RAI 8) It appears that the coordinates for the Central Field SW Entrance are incorrect. Please check them and revise the Exhibit A text as necessary. (The coordinates listed for this entrance appear to be near the Varra Coulson Project.) Raptor Materials First Adequacy Response Three locations were corrected as reflected in the revised Exhibit A, and verified via supporting Snippets of the coordinates captured from Google Maps, which follow, below: Southwest Entrance: The Homestead (North) Entrance: Evans Colorado 40.341859, -104,783755 The Primary Entrance (#8): Evans Colorado 40.349126, -104.774905 9IPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Iwo Rivers Sand, Gravel and Reservoir Project — M2022-013. 14857-14707 Co Rd 396 nil Milliken, CO 80543 AO 34B1 50 -104 7 Tho 1? Division Second Adequacy Comment No additional response IS required from 1 t. 6.4.3 Exhibit C - Pre -Mining and Mining Plan Maps of Affected Land 9) The irrigation ditches need to be clearly shown and labeled on the Existing Conditions Map (Exhibit C-1). P for Materials First Adequacy Response The Evans Ditch is labelled. The internal irrigation ditches are owned and controlled by RN/l, are visibly evident in the aerial image. While these company owned ditches are predominantly outside the extraction limits, some are inside the extraction limits and will be lost to extraction. MEI 34. r 7 '. --« j r r THE r _ fi µ E E �T~ i Division Second Adequacy Comment No additional response is required from RAI 10) Also, per Rule 6.4.31, the existing vegetation at the site should be shown. Raptor Materials First Adequacy Response 101Page e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M 2022-013. Aerial images are provided to reflect a better understanding as to the nature of the diverse vegetation that either exists or could exist over the affected lands. Since it is stated that extraction occurs with the cropped lands exclusively, the denuded lands shown in the aerial image reflect the seasonal absence of crops. Crops may vary in composition from year to year, so any manifestations as to what kind of crop, if any; or the state of cover, is somewhat misleading. Still, while we believe the aerial image satisfies the requirement, it should also be understood that this submittal is consistent with those submitted to the O ILR since 1999. We believe your colleague, Peter Mays, can attest to this. Further, there is ample information in Exhibit ILI - where the native vegetation that may exist as correlated to area soils is fully manifested in the included Range Site Descriptions, per SCS/NRCS publications. Further, information is provided that much of the cottonwood corridors that occupy a majority of the riverine areas have vegetation that is atypical, since it is highly overgrazed or otherwise disturbed by natural conditions, sporting a near monoculture of smooth brome or diverse annuals. Division Second Adequacy Comment No additional response is required from RM 11) The scale on Exhibit C-1 appears to be incorrect. Please check and revise as necessary. Raptor Materials First Adequacy Response It was off, but so little you could just see a minor shift in the image as the Scale was remedied. A corrected version at lit = 400' of the Original Drawing now in .pdf, is included with this submittal. Please keep in mind that in the translation of highly complicated drawings produced in Autodesk Civil 3D and Raster Design, some loss may occur as Adobe attempts to translates the .dwg files of Autodesk, into usable .pdf files necessary in communicating the OMLR permit to a diverse agency and public audience. Then (the scale reflected as indicated at 0.002496): 111Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy l .etters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project — M2022-013. by L .leer gear 1 Pitch = 4O0 feat V LL .3 it X a 0.002496 r Now (the scale reflected as indicated at 1 inch = 400 feet — as set in Model Space). Note: Revised Map with corrected scale included in .pdf with this digital submittal: Crown by. B! mn� f inch = 400 feet w )a O s-r.M t ln:d+ = 400 fart tAt: Qt Novvnbcr 2021 tvISMit 22 Febvuary 2022 P ACE: 1 it I It i", Yi-1 La __ Division Second Adequacy Comment An additional response is required from RM. The scale bar appears to ha i ve incorrect numbers. Rather than 400 feet and 800 feet, it appears that the numbers should be 200 and 400. Raptor Materials Second Adequacy Response The scale bar on Exhibit C-1 has been corrected as requested. 12) The legend on Exhibit C-1 includes the 100 -year floodplain, but the floodplain lines are not on the map. These lines should be added to this map as well as the Extraction Plan Map, Exhibit C-2. Raptor Materials First Adequacy Response The 100 -year floodplain intersects the affected lands only to the north of the Big Thompson River and can be seen in both drawings. It's clearly identified in the C-1 Legend where the 100 Year Flooclplain appears in True Blue. The line remained as a reference on Exhibit C-2, but having been called out on C-1, did not appear in the C-2 Legend. 12 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuher, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project — M2022-013. • r • r "t I 1 • Division Second Adequacy Comment a' REC. NO.' 1 959e (ExcLPTIcre 70 k 29,E z. . = +Ti's -'s .33-1'5H 6. _ - -" �--` -` �' ge er ;' ft is .. ., ; a e„, _ V 0' EASottErir Ric NO 2410746 3 No additional response is required ed from Rail. 13) For the sake of clarity, the Division recommends that the entire permit area be permitted to be affected, and this should be stated in Exhibit. C and Exhibit D. (The Division recognizes that this statement is made in Exhibit L.) Raptor Materials First Adequacy Response Your language is accurate, for it provides more precisely that all lands within the permit boundary may become 'affected lands.' Regardless, this statement is included in the Original Submittal - Exhibit D, Pages 5 and 8: 13 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project - M2022-013. 64.5 EXHIBIT D - Extraction Plan I5.1 i± feet from the surface, we determined the Static Water Level using the upper limit of 5.0+ feet The Cyan colored contour shown on exhibit G: Water Information Map represents the Static Groundwater Elevation at 4675' at North-West Field, and 4673' at Central Field. Since completed reservoirs will be lined to i eet State of Colorado Water Resources specifications and requirements, and since lined basins will ultimately equalize with the surrounding groundwater elevations, the Static Water Levels shown should reasonably reflect those of the both the lined or unlined state; and represent a proper reflection of the optimal surface area of the water over the finished basins. Varra Companies, Inc. has sufficient water to meet the circumstances and obligations of both the lined and unlined states; and as reflected under Exhibit G: Water Resources Information; until and -unless the reservoirs have an approved liner, the Operator will dedicate sufficient waters to secure the reclamation of the resulting basins in the unlined state. Planned Field Activities: The 409.23± acre parcel boundary forms the permit boundary, as reflected on exhibit maps. All lands under its direct control within the 409.23± acre permit area, are affected lands under C.R.S. 34-32.5-- 103(1), respective of this permit application. As a result, any changes required in the nature of planned extraction or reclamation will be made only through the Colorado Office of Mined Land Reclamation COMM), by Technical Revision only_ If lands are needed beyond the designated permit boundary, those lands will be secured for the active OMLR permit by Amendment AND: Es 6.4.5 EXHIBIT 0 - Extraction Plan Operations will predominantly utilize unmodified existing agricultural field access roads (unless otherwise indicated), which will themselves be subsequently extracted in time where they fall within the extraction limits shown on Exhibit C-2: Extraction Plan Map. No other defined roads within the Extraction Limits will occur except for the temporary paths created by extraction equipment, or others -vise determined by subsequent Revision to the permit. All existing agricultural roads outside of the designated extraction limits will be retained according to the desires of the landowner. The same shall form part of the final end use of the reclaimed lands, unless otherwise indicated in this submittal or by subsequent permit revision. For purposes of this submittal, all lands within the indicated permit boundary xvill be considered affected lands] but only those locations between the existing access roads, and which otherwise remain above the anticipated static water level of the resulting basins, will be soiled (where soil is absent) and seeded to establish vegetation consistent with the approved reclamation plan. Division Second Adequacy Comment No additional response is required from Rile. 14 Page Correspondence to the Colorado office of Mined Land Reclamation — Reply to Rob Zither. EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. 14) During the pre -operations ground truth inspection on June 14, 2022, the idea of relocating the access point at the northwest corner of the site (to the east) was discussed. Please update Exhibit C-2 to reflect any change in that location. Raptor Materials First Adequacy Response No changes to Exhibit C-2 are necessary as no change is proposed to access at this time. Alternate plant site development and access may be considered at a later time if possible and in consultation with the City of Evans.. Any future changes will be included as part of a Technical Revision to the approved permit at that time. Division Second Adequacy Comment No additional response is required from RAt. 15) Please add the following to the Extraction Plan Map, Exhibit C-2: roads, parking and equipment storage areas, levees, soil piles, keyways, settling basins, and other structures pertinent to the mining operation that are not currently shown on the map. Comments on the map can indicate where these features are subject to change. Raptor Materials First Adequacy Response There are no established parking and equipment storage areas. Parking may occul- within planned active extraction, along existing access roads, or within the 1 lom t: stead location. Levees are also access roads for street legal vehicles and service trucks. These roadways atop the levees are not designated for extraction and are visible to scale on the outer perimeter of planned extraction areas. There are no soil piles at this time, except that identified as stockpiled soil from the adjacent Westervelt Wetland Bank, and as established and set aside over the entire NE Section of Central Field, as stated in the application. Updates to soil stockpile conditions over the NE Section of Central Field, or other locations, may also be updated in required Annual Reports as conditions warrant. As previously stated in the application, keyways are a feature that run at or near the toe of extracted slopes. It is unprecedented to show them in an application but can be updated in required Annual Reports to better reflect their size and extent, as they are field fit concurrent with extraction progress, which may vary in a manner 151 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob 'Luber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. difficult to portray in advance. Here's some additional information taken from the application on the planned keyways: 6.4.12 EXHIBIT L - Reclamation Costs follow the perimeter of the extraction limits over approximately 75.45± acres in order to establish the perimeter keyway for the 127.10± acre Center Section of Central Field. The perimeter extraction will leave a 51.65± acre Core, that may be extracted as needed as keyway drainage capacity allows. The initial extraction area is bordered to the South along a near 800± foot section of oil and gas line that is pending removal; along with the two oil and gas wells, also pending removal (refer to Exhibit C for ownership details). Extraction will not occur within 10 feet of these lines, or 25 feet from the wells, as indicated in the setbacks detailed under Exhibit D: Extraction Plan. Below this gas line is an existing pond and well that will be used as a Settling Basin Area, containing at present a solitary settling basin and pump as a point of discharge of groundwater. This pond may be expanded or added to below this line, and may then beextracted itself once discharge is discontinued for Central Field Operations. Perimeter Keyway Extraction will maintain a perimeter slope no steeper than 1.25H:1V, except for the perimeter shown in red along it's extraction limit, and respective toe where cut slopes will not exceed 2.00H:1V; as indicated (refer to Exhibit S: Stability Analysis for additional information). At the toe of the cut perimeter slope is the keyway that runs below the extracted deposit of the basin, into the bedrock, which allows the subsurface waters to flow to the settling basin and discharge pumps necessary to keep the cut basin dry during a time of extraction and reclamation of the affected perimeter slopes. The keyway dimensions may vary more or less from 4± to 8± feet in depth and 4± to 16± feet in width. Extraction must be broad enough to allow equipment to safely approach the toe and exise the bed dimensions where the resulting channel is sufficient to convey the groundwaters to the settling basin for discharge. Please Note: The graphic representation of the Perimeter Keyway Extraction and Core are Idealized, and may vary in shape and size presented. Annual Reports will report on the nature and extent of affected lands and more properly reflect actual conditions on the ground in a given year of operations. Division Second Adequacy Comment • The Division Islon reiterates tes that structures related to the 1771.171. ; operation need to be on Exhibit C-2. Regarding soil piles, RA'l states in the responses that, "There are no soil piles at this time. ho we vof ; the purpose of the map is to illustrate the plan for soil piles in the future, and those should be sho 111n on them p. • The Division requests that the term "keyway" be clarified by RM. Is this actually a de- watering trench? • The purpose of Annual Reports is described in Rule 1.15. These reports are not to be used to make changes to the mining and reclamation plans. Those changes must be made with technical revisions and amendments. 161 Page Correspondence to the Colorado Office of Mined Land Reclamation a Reply to Rob Zuber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Raptor Materials Second Adequacy Response • The temporary soil stockpile location in the North-East Section of Central Field is labeled on Exhibit C-2. • R '1 confirms the term "keys ay" as used generally in the Two Rivers application is a de- watering trench. This is clarified in each Exhibit where the term is used when referenced for the first time. • Acknowledged 6.4.4 Exhibit D - Mining Plan 16) In this and other exhibits, an effort should be made to update agency names. For example, the Colorado Division of Wildlife is now Colorado Parks and Wildlife. The abbreviation CDI1 should be CDPFIE. Raptor Materials First Adequacy Response Please refer to the discussion as it applies to the use of agency names and anacronymst as discussed in the Prologue, above. Division Second Adequacy Comment No additional response is required from RAC. 17) The mining plan (aka extraction plan) requires more detail. In particular, the plan should include a schedule that specifies the areas to be worked for given phases, with ranges of time periods. The phases described in Exhibit D should he coordinated with the Extraction Plan Map, Exhibit C-2. The operator can change the plan later, as needed, with technical revisions and/or amendments. Additional clarification on the sequence of the mining plan is necessary to calculate the required financial warranty. Raptor Materials First Adequacy Response Fields vs. Phases: As detailed in the Extraction Plan over pages 13 and 14 (copied below), we detail a modified Phasing Plan based upon Field Sections. The NW Field is Separated in the whole by a public road from Central Field, while Central Field is bound together in three contiguous Sections (you may consider them Phases, although not sequential phases as they can be accessed simultaneously in time). So, the Fields and Sections are distinct from conventional mining phases, in that with enough Warranty, any or all can be accessed and extracted independently and simultaneously, instead of sequentially. 17iPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. One of the attributes of our Established Extraction Methodology is the use of flexibility to aid a rapid access to the deposit and completion of the basin. If needed, four separate extraction teams could be set up in each section or Field to speed or adjust the extraction timeline. This has been a feature accepted by the office over many submittals and many years. Your own Specialist, Peter Hays, can attest to this. The timely application and use of Annual Reports, or Technical Revisions, to anticipate and adjust attending Financial Warranty to allow the operations to pulse over time is a humble approach that respects the requirements and objectives of the Rules and Regulations. The idea is designed to reduce the need for untimely delays and expensive permit revisions, as well as needless field operation conflicts that can also jeopardize Compliance with otherwise rigid self-imposed constraints. The greater beneficial effect is to flexibly match extraction and subsequent reclamation as operations adjust more naturally to shifts in market demand that determine the functionallife of the mine. This is a projected 35 -year life of mine operation that could be shortened or lengthened by economic influences and other factors for which we and your office cannot reliably or genuinely foresee. This answer will play out for Exhibit L as well, as the entire described Onset Area is not essentially planned for disturbance, simply the area where initial disturbance may onset, however, given possible directions NE and SE along an idealized core, could affect 8-16 acres over the course of the initial 2 years, unless we hit a depression and it takes 10 years instead. Unlikely as either are, they are projections in time. The actual areas will be monitored using aerial imagery and handheld survey instruments to monitor and report the acreages and make revisions to the Plan and estimated warranty in response to the current market drivers of the business. We will then reflect this on related maps and as content through the annual report process as determined at the time. .Active Resotute Recovery: Follomng soil salvage, the balance of the extractable deposit will be removed to the depth of the unconsolidated or weathered bedrock, transported by conveyor to the plant site pit nin, and subsequently manipulated as desired by screening, crushing, washing, and other methods to size and properly dimension the earth product into diverse merchantable materials for sale. Resource recovery will commence radially North and East from a post near the extsting pond and planned first discharge point shown near the Southern boundary of Central Field. There are no fixed sequences or phases scheduled as part of the extraction plan. Instead, Wilds are used instead of Phases to describe the activities, since each Field can be accessed concurrently instead of sequentially with the 181 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. 14 6.4.5 EXHIBIT Da, Extraction Plan other; as reflected or otherwise updated as part of required °NEER Annual Reports. Under this method, extraction is "pulsed,' As such, the rate of extraction and subsequent reclamation will slow or quicken according to influences of the markets, weather, and internal logistics. Flexibility in operations encourages better outcomes when adapting to changing circumstance or unexpected field conditions, and may involve actively working different fields or different parts of the same field as necessary_ Generally, flexibility aids integrity of operations and encourages optimizing operational activity and subsequent reclamation of affected lands. Therefore, any method that accelerates the extraction timeline - be utilized, and should be encouraged to better engage the unpredictable elements and variables that reasonably affect the capacities of the Operator. Exhibit C-2: Extraction Plan Map, shows the location and p1. red extraction limits, general direction of extraction, and related features described above; along with features made obvious in the included aerial image of the permit location and surrounding lands. Additional info ' anon is provided under Exhibit C-1: Existing Conditions Map; which shows all known current and active significant man-made structures located on or within 200 feet of the permit boundary detailed under including creeks, roads, buildings, oil and gas facilities [such as tanks, batteries, wells and lines), and power and communication lines and support structures, easements and rights -of -way: located over the permitted lands or within 200 feet of the same. A listing of the adjoining surface owner's names and addresses located within these areas are listed under Exhibit C Text, correlated with those shown in the afore -mentioned Exhibit C-1: Existing Conditions Map. Division Second Adequacy Comment RAJ needs to clarlfv an apparent contradiction between the response to item #17 and the approach to minimizing impacts on wildlife. e. as required hr Rule 3.1.8. On page 15. the response states that "four separate extraction teams" could be used to hasten the extraction schedule. Hon -ever, the FRO memorandum £4u cast 26, 2022; page 2) describes an incremental approach that protect mule deer habitat by on - disturbing a relatively small area at one time. The text in the memo suggests (hat a lil8X1t11LIM size Mr an active cell is 16 acres. This example illu s tra te's the need to better define the mining and reclamation on plans. Ra for Materials Second Ade uac Res onse The First Adequacy response has been incorporated into the revised Exhibit D (p16, Footnote 4). Also, in revised Exhibit D, the wildlife concern has been 19' Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, ED'S — Adequacy Letters or 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2O22-013. addressed and is supported by a letter from Ron Beane, Senior Wildlife Biologist with wildlife consultant ERO Resources Corp attached as an addendum to Exhibit D (p17, Footnote 6). 18) The discussion on pages 6 and 7 regarding structures and easements should discuss which structures and easements will be relocated or removed from the site (if any). Raptor Materials First Adequacy Response For lands within the Extraction Limits, only those structures, easements, and rights -of -way shown in Exhibit C-2: Extraction Plan Map, are anticipated to remain from those shown under Exhibit C-1: Existing Conditions Map* If changes to existing or possible revised structures, easements, or right-of-way are in any manner retained, or where they might occur subsequent to OMLR approval of this application, then a Technical Revision will be submitted to update Exhibit C-2: Extraction Plan Map. All established set -back distances from planned activities will be maintained regardless. Operations are not intended to affect existing structures, Easements or Right -of - Ways within the Planned Extraction Limits or related Processing Areas and Wash Pond, and are designed to avoid and retain any structure, Easement or Right -of - Way on the surface, and subsurface. Future agreements may be reached allowing mining in areas currently identified as being restricted to mining containing certain structures, Easements or Right -of -Ways. Exhibit C-1 shows and identifies all these features understood by us, and the respective Surveyed information, and correlated Observation and Title Work upon which they are based and represented on the attending Maps. The Maps are not Surveys. They are Maps and as such, they comprise a reasonable representation of all site features. but must not be relied upon by themselves exclusively for location purposes. Maps and features are not a substitute for identification of underground structures and will rely upon location services of the 811 service. Exhibit C-2 shows the remaining Oil Wells and Lines within Planned Operations at the time of the Submittal. Any revisions, additions, or modifications of residual Oil Wells or Lines will be avoided as represented on updated Maps and Revisions to the Permit, and consistent with Setback Distances identified in this submittal. Removal of any Existing Structures such as the Oil and Gas structures and or lines, will be updated on required Annual Reports, or by Technical Revision, as warranted, or as otherwise directed consistent with Colorado Statute. 2O Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Division Second Adequacy Comment As noted at the beginning of this letter, RAI needs to revise ise actual exhibits (in this case Exhibit D) to address adequacy items and re -submit there. Also. please address the particular structures (aboI re ground and underground) and easements sh o wn on Map C-1. Raptor Materials Second Adequacy Response As requested, Exhibits C-1 and C-2 have been enhanced and an updated table added to Exhibit C-1. Further the matter is addressed in revised Exhibit D (p7, Footnote 1). 19) on page 7, more detail is needed for the roads onsite. Please explain which roads will be built and which will be modified. Explain construction method and dimensions. Raptor Materials First Adequacy Response All lands within the Extraction Limits will be traversed during extraction and are not roads. Areas outside of Active Extraction that have existing agricultural access roads below the existing riverside berms, may be accessed by all manner of vehicles and equipment and may be modified accordingly. In this instance, these are not leased lands but Owner operator lands. As such, any improvement of existing access roads, or creation of new access roads, are capital improvements of the land. Therefore, all improvements to access are an asset to the landowner, and as such, will not be removed by a default by the operator, but retained subsecuent to extraction where they are not otherwise removed by the same. This is established real property law. As to design widths and composition, this will be field fit and determined, and updated in required OIVILR Annual Reports. Road widths will vary but may typically be 10 to 40 feet wide depending on end use. Road surfaces will be fit for purpose and constructed using site produced materials if necessary to improve or establish the running surface. Division Second Adequacy Comment No additional response is required from RM. 21' Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 20122; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. 20) on pages 12 - 13, the discussion on stockpiles should include text indicating that soil management practices will protect the soil piles from erosion, prevent contamination of the soil from toxic or acid-forming material, and ensure that the soil will remain usable for reclamation. Raptor Materials First Adequacy Response Comments 20. 23 and 32 we believe are best addressed in a comprehensive rather than fragmented manner. Consistent with the backfill permit, it would be highly unusual that an alluvial aggregate operation would find potentially toxic or acid forming materials, nor would they if found be utilized. Sulfur is sometimes used on plains soils w=here acidification moderates alkalinity or the planting of evergreen trees which prefer a slightly acidic soil. Nonetheless the operator's intent is not to create or import such a problem. If found on site such materials would be disposed of in an. appropriate landfill. The application does attend to the real threat on irrigated lands, which is the accumulation of salts due to evapotranspiration in some circumstances of the lower soil profile, which profile is significantly absent in Unit 3 Soils, as iterated here: Continued...next page... 221 P a g e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Soil Morphology 6.4.5 EXHIBIT D -- Extraction Plan Unit 3 soils commonly form with ni floodplains. As a result, differing states of soil formation may exist within the soil unit designation; such as soils with little horizon development like E tisc, is and I s..pt soIs. Mg114,9k, with deep well -developed horizons may exist in the minority and the near fringe of planned extraction. Refer to graphic above, and bleow. Ince Awl 1, I alt o- With over a century of agricultural manipulation of area agricultural fields, prior mixing or importation of soils for land leveling, or flood plain management in the creation of levees, may have dramatically altered the original native soil profiles and properties. The native A profile of the upland terrace found within the agricultural Fields at the T, is predominantly modified as a plow CAp) layer of 6.0± to 8.0+ inches. The historic practice of incorporating manure into the plow layer should have served to maintain the organic base and quality of the cropped soils and accelerated soil horizon formation and development where it was lagging. Since the cropped soils have been irrigated, care should be taken not to salvage soils greater than 12.0- inches in depth to avoid mixing of potential accumulated salts. We use Exhibit In to expand upon soil and Vegetation considerations that are also considered relevant to Exhibit E the Reclamation Plan andcorrelated as well in attending supplemental information provided from the U.S. Natural Resources and 23IPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project —1 M2022-013. Conservation Service (formerly the U.S. Soil Conservation Service). The SCS were the principal authors and creators of soil conservation and management throughout the United States, and the first to systemically incorporate plant -soil -water relations in their considerations, which are certainly a factor in our own and reflected in the correlated exhibits to reflect their influence and relevance in this submittal. Persons familiar with the SCS/NRCS, know these are the authors of Soil Stabilization, so we commonly locate this information under Exhibit In, where the information used for those considerations resides. Subsequently, what follows is a guide through the Application to reveal how the matter was addressed. We hope this clarifies and assures the office in this manner. It should be understood that the application attempts to guide the reader point blank, as follows: 10 6.4.5 EXHIBIT D -- Extraction Plan Soils found within the entire project area are described more thoroughly under Exhibit 1 - Soils Exhibit, and the attending Exhibit i/J - Soils and Vegetation Map, shown not to scale, above. Additional geologic considerations are also included under Exhibit S - Stability Analysis. Area and Site Geology: The area geology is typified by mixed alluvial and Soil Stabilization methods are rather extensive in the application, intended to minimize erosion and impacts to waters and adjacent lands. Specifically, soil salvage and stockpile stabilization are called out by topic under Exhibit D, as follows: Continued...next page... 24 I P a ' e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August. 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Soil Salvage: Resource recovery will commence by first removing the upper IA profile/plows' layer] six to twelve inches of soil Nix (&_mi) inches typical], combined with existing grass or crop stubble. Removal will utn1l7e scrappers or excavators, aided by dozen where necessary, and hauled to the Northeast Section of Central Field. All extraction and surface related activities detailed in this application will occur under an approved Fugitive Dust Permit issued by the Colorado Department of Public Health and Environment (CD ). until resoiling activity occurs, where harvested soils have been stockpiled and remain undisturbed for reclamation or sale, they will be seeded with the mixture specified under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. A stabilizing cover of native vegetation may take up to three years to fully establish the desired cover. In the event the native seed mixture fails, an optional mixture of predominantly introduced species will be used as a fall back to better assure a stabilizing cover of vegetation_ Still, using the Page 113 6.4.5 EXHIBIT 0 - Extraction Plan preferred native seed mixture offers opportunity to gauge the potential performance of the selected species prior to utilizing it over larger areas requiring reclamation later in the life of the resource recovery operation_ Once vegetation is established over the initial reclamation soil stockpiles, they will likely remain untouched for the life of the operation until final reclamation of remaining affected lands takes place. Where concurrent reclamation is possible, operations will utilize soil in an over the shoulder method when practical_ In this manner, reclamation is expedited without increasing soil stockpile volumes while reducing expenditures related to labor, handling, and time. Where are no agents preventing the soil from functioning for reclamation other than the inevitable loss of some native soil structure, organic matter, and fertility that can be compensated for by any analytically determined need at the time of resoiling and revegetation, via analysis using of soil samples by the CST Soils Laboratory. This and other measures are detailed in the application under Exhibit WY soils and Vegetation Information, as follows= Con.tinued...next page... 25IPa`e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Once applied to the surface, the new soils will be exposed to the raw forces of erosion until adequate vegetative cover and root mass develops. Erosion requires both detachment and transportation in order to occur. Running water, wind, and raindrop impact are the main forces of erosion acting upon the soil. The use of a sterile hybrid live cover crop will aid in the stabilization of the soil by allowing a quick vegetative cover to become established in advance of the native grasses. The hybrid will also serve as an aid to reduce competition resulting from the establishment and growth of unwanted pioneer species (weeds) on disturbed ground. The attending reclamation seed mixture, and as approved, has a provision for the use of a sterile hybrid grass in lieu of mulch. Mulch, even when crimped with specialized equipment, is subject to being blown off the property, or reduced to an ineffective stubble. Often, it has been observed to intercept rainfall where it quickly evaporates from the stubble surface, limiting the benefits of light precipitation by preventing infiltration and percolation of moisture to the root zone. The hybrid on the other hand will establish quickly, but since it is sterile, will not continue to compete with the emerging native grasses. After two to three years, the hybrid grass will begin to die out just as the native grasses emerge and improve their dominance over the revegetated areas. increasing organic matter, such as the incorporation of manure into fallow soils, will aid in the restructuring of the new soils by increasing the moisture and fertility holding capacity of the upper profile seed bed, while simultaneously facilitating healthier plant -soil -water relations and overall root development of the emerging grasses. As the roots of the emerging grasses develop and mature over time, the resulting root mass will serve to build upon the base percent organic matter content of the new soils, thereby increasing the potential for long term survival and spread of the established grasses. Soil testing may occur on the new soils to better gauge the need or success of any applied organic soil amendments respective of the resulting vegetative cover. The addition of fertilizer may also aid in the establishment, growth and survival of the emerging grasses. Fertilizer may be applied to the seeded areas at rates determined from soil tests of the reapplied soils. To this end, soils may be sampled as needed. Sampling will utilize a hand auger and approved NRCS soil sample bags, and utilizing recommended procedures. Any soil testing will be conducted by the CSU Soil Laboratory in Ft. Collins, Colorado. The tests will be used to monitor soil quality and suitability of any amendments. Fertilizer may be withheld until after emergence to deter the encouragement of weed species. The use, composition and rates of i7 6.4.5 EXHIBIT I/J -- Soils and Vegetation Information fertilization will be determined prior to the time of seeding where appropriate, and may be reported in the OMLR Annual Reports, as appropriate. WEED MANAGEMENT PLAN: Because the Agricultural Fields are the only planned area where the deposit itself gill be extracted, it should be understood they are within the floodplain of two rivers. As such, stockpiling and placement of soil is initially designated outside of the flood plain on top of the pre-existing soil stockpile located over the NE Section 261Page Correspondence to the Colorado Office of Mined Land Reclamation —Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. of Central Field, until such a time as sufficient detention can be createdi to accommodate above ground stockpiling. The application provided a copy of the Westervelt project detailing that this area of extraction was removed by the City of Evans from the floodplain. There are no floodplain impacts anticipated by continued stockpiling of soil over that location. We can affirm here that stockpiling above the existing ground elevation will not occur in a manner understood to obstruct flood waters where they might occur within the existing floodplain. It is understood and agreed here -in that their longitudinal dimensions if they occur there should extend parallel to anticipated flood flows where they exceed a cone or other shape that might find its existence contrary to intent by volume beyond that which could he understood to be temporary, or transitory; especially outside of seasonality where flooding might be more reasonably anticipated. What follows is information provided in the application (Exhibit I/J) that was intended to address this concern as to existing volume stockpiled at that location: and a volume which exceeds the necessary volume needed to reclaim the completed project. The thickness of topsoil capping to be placed is stated as "All affected lands between the extraction limits and remaining above the anticipated high-water mark of the basins will be capped with a minimum of six (6.o±) inches of soil, as supported by Exhibit I T J Soils and Vegetation Information." In Exhibit E (p5) and "there is sufficient soil to assure a re -soil depth of approximately six inches over the basin banks above the anticipated static water level of the reservoirs" in Exhibit I/J (p4). Haul and push distances to re -soil will vary based on the actual progress rate andactive sections of the operations. Where possible once the operation matures over the shoulder placement will be employed where possible for efficiency and best outcomes with soil. RM will report this activity in the Annual Report as the circumstances for re -soiling become clearer. 27IPage Correspondence to the Colorado Office of Mined Land Reclamation - Reply to Rob Zuber, FE'S - Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project - M2022-013. 6.4.5 EXHIBIT I/J — Soils and Vegetation Information A portion of in situ soils may be used in an over the shoulder method to resoil the completed banks of basin slopes or other upland areas in time. Commonly, soils will be parked in stockpiles until ready for application in a manner more fully desaibed below. Consistent with existing zoned agricultural practices, soil from an adjacent wetland bank was approved by the City of Evans, and completed in early 2021. The City of Evans approved (refer to the Addendum at the back of this Exhibit) the placement of these soils within the floodplain of the upper North-East portion of Central Held, as shown on Exhibit C-2: Extraction Plan Map. These orphan soils are in place, seeded, and the area remains under continuingagricultural production, yet are no longer part of the area floodplain. The current extent of this 200,000± cu.yd. stockpile is represented on Exhibit L: Financial Warranty Map. This stockpile location area will also receive a portion of soils removed from planned extraction locations over other areas of Central and North-West Fields. It should be noted that a monoculture of cultivated corn occupies a majority of the planned areas of extraction, and will gradually be turned out of production through extraction. This soil may be utilized to line the resulting basins/ for reclamation of affected lands above the static water level, or for market as warranted. Division Second Adequacy Comment No further response required. The Extraction Plan does discuss how soil piles will be stabilized. It also discusses ho iv fertilizer can compensate for the loss of organic matter, Finally, the applicant has stated that potentially - toxic or acid forming materials would not be utilized in the reclamation activities. 21) on page 14 in the second to last paragraph, the sentence that begins "specific variations in the location of • • •" should be rewritten. The structure of this sentence does not follow standard rules of grammar, and (more importantly) the meaning is not clear. Please revise this statement accordingly. Raptor Materials First Adequacy Response The paragraph segment was simply a DRAFT oversight. There is a tendency to look at lines drawn on a map in a rather precise manner. The forces of nature have laid down a valuable resource that cannot be defined with absolute precision and consequently, applications and actual conditions combined with human error and massive equipment sometimes are unable to make that pencil lined vision in ink line up with reality. Slight variations and departures in the field may occur from time to time, often to ensure safe conditions, minimize impacts, or to fulfil an obligation to maximize the recovery of the resource. Here's a better version that now clarifies this spot under Exhibit D: `Minor variations may occur in the field over time from those represented on 28VPag Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Exhibit Maps. The plans detailed in this application are based upon future events for which minor or temporary departures at any point in time may be evident. To the extent any, significant departure 117 the field occurs in a time and manner not otherwise anticipated in these exhibits, the operator may cure by self -inspection, by observation from OM' ' inspection in a timely manner; or by operator -initiated Revision to the Permit or otherwise erwrse via clarif ca (on in attending required WMLR Annual Reports. Division Second Adequacy Comment R I needs to revise Exhibit I) to address this item and re -submit it Raptor Materials Second Adequacy Response The First Adequacy response provided has been added to revised Exhibit D as requested (p17, Footnote 7). 22) on page 14 in the last paragraph, the units are not specified (appears to be 125 feet), and this should be revised. Also, add a discussion on pipelines to this paragraph as appropriate. Ra for Materials First Ade uac y Res onse As seen on the paragraph preceding the oversight, as reproduced by Snippet, below; underground gas lines or other underground facilities are referenced. The missing units are confirmed as `feet, . Continued...next page... 29jPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project - M2022-013. The extraction limits assure through the use of setbacks that other interests are not affected by planned extraction. Extraction is set back uniformly at a minimum 10.0± feet from the edge of property lines; easements and rights -of - way; underground gas lines or other underground facilities, ties, irrigation ditches and seep ditch, \veils and other structures. Specific variations in the location of: stockpiles, boundaries of extraction, and related infor m. ation relative to adjacent structures and easements; from that represented on Exhibit C-2: Extraction Plan Map. Extraction will not occur closer than 1.25-± 'from the face of a residential structure; unless there is a written accommodation with the owner of the residential structure that allows extraction to occur within a closer stated limit. Extraction will occur no closer than 25-± feet from well heads and related above ground facilities. Extraction around well heads will be concurrently backfilled to maintain a 100± foot buffer from the balance of extracted lands. At all VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OP REC AMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 115 6.4,5 EXHIBIT D — Extraction Plan Division Second Adequacy Comment R I needs to revise ise Exhibit I) to address this item and re -submit it. Raptor Materials Second Adequacy Response The revised Exhibit D has beencorrected as requested (p18, Footnote 8). 23) On page 16, regarding the discussion on topsoil and overburden stockpiles, more detail is needed regarding the storage volumes and locations of the piles, including distances from the piles to the areas to be reclaimed. It is recommended that they be shown on Map C-5. It should also be stated that the piles will be configured to prevent obstruction of flood waters, namely elongate the piles to make them parallel to the flow direction. 30jPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project — M2022-013. Raptor Materials First Adequacy Response There is no reference w e can identify on p16 to stockpiles, at least not explicitly. There is discussion of backfilling cut slopes and topsoiling above water line. Nonetheless items 20, 23 and 32 all broadly relate to topsoil and need to be read together via a consolidated response to comment 20. Division Second Adequacy Comment It appears that the extensive discussion on soils does not include any information regarding the quantities of soil in stockpiles or the location of soil piles. This information is required for a detailed reclamation cost estimate and needs to be added to the Extraction Plan, Exhibit D. Raptor Materials Second Adesuacy Response The information requested has been included in revised Exhibit D (p 14, , Footnote 2). 24) In the section Plant Site Development &.. Operations, text should be added regarding the details of structures that will be built, including the conveyor. Dimensions and other details should be provided to aid in the estimate of demolition costs for these structures. Raptor Materials First Adequacy Response Equipment to be used at the plant site is described in the Plant Site Development and Operations section on p19 as shown below. Plant site equipment will be semi - mobile in nature and is not expected to require permanent foundations or footers. The conveyor will be set on an elevated structure at varying heights to be situated about the 1 in 100 -year flood level. An average height of 7 feet is expected. The conveyor will be supported by legs at intervals of approximately 20 feet with concrete blocks used as necessary to anchor the legs. Final conveyor specifications are to be determined but a 24-36" belt is anticipated. 311Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob tuber. LIPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — .M2022-013. Page 119 6.4,5 EXHIBIT O - Extraction Plan north-west of the existing Evans Ditch as it courses winds north of the Big Thompson River. Plant activities will require a wash plant and attending wash pond to recycle wash water and receive discharge silts and other reject fines from the washed product. Plant and Wash Pond areas are identified on Exhibit C-2: Extraction Plan Map. The wash pond will function as recycling wash water and receiving basin for reject fines for the intended Pl _ s t/Processing activities. Since the basin functions in a dosed system, it will not require dewatering. Once the wash pond is established, wet plant operations can be created and join any dry plant activities in progress. Dry Plant operations can be readily established since water is not integral to their operations. Once established, wash pond water win function as a closed system_ Settled materials from wash Ponds will be utilized as product or for reclamation as desired. Plant equipment will include, but is not limited to, a crusher, screens, and conveyors, scale house and scale, and attending equipment. Resulnng stockpiles of pit run and processed products may be temporarily stockpiled here with processed stockpiles, or combined as needed, until transported to market_ Division Second Adequacy Comment • More detail is needed regarding the conveyor. or. Please provide the size of the conveyor Also, pr. o Fide the dimensions of pads and other foundations that will be used for this structure and provide an estimate of the total volume of concrete that will he used. Related to this. Exhibit L will need to he updated to include the cost of dismantling the conveyor. • Please describe the nieasures to be taken to prevent material from overtopping, - the conveyor s;steal and falling into the Big Thonipson River ; ,i Ra •for Materials Second Adequacy Response The First Adequacy response provided has been enhanced and added to revised Exhibit D as requested including additional discussion on how material originally placed by the river will be prevented from falling from the conveyor back into the river (p23, Footnote 9). 25) In the section Plant Site Development &z Operations, text should be added regarding the control of prairie dogs. Will they be relocated? IPage Correspondence to the Colorado Office of Mined Land Reclamation - Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project - M2022-013. Raptor Materials First Adequacy Response Please see response item "Issue - Prairie Dogs" prepared by ERO dated August 26, 2022 attached as an addendum to Exhibit H. Division Second Adequacy Comment No additional response is required from R1 26) The applicant should discuss the following (related to Rule 3.1.8): How will the operation minimize impacts on mule deer habitat during the winter season (December 1 through April 30). This should include (but not be limited to) a discussion on fencing. Fencing should be limited as practical, and wildlife -friendly fencing should be used. Raptor Materials First Adequacy Response Please see response item "Issue - Mule jeer- (severe winter range and migration corridors)" and "Issue - Fencing" prepared by FRO dated August 26. 2022 attached as an addendum to Exhibit H. Division Second Adequacy Comment No additional response is required from RI I. 27) Include a discussion on how the operation will allow for deer and other animals to escape the mining operations. Ra for Materials First Adequacy Response Please see response item "Issue - Escape Ramps" prepared by ERO dated August 26, 2022 attached as an addendum to Exhibit H. Division Second Adequacy Comment No additional response is required from RM. 6.4.5 Exhibit E - Reclamation Plan 28) The Application form specifies that the post -mining land use of the site will be Developed Water Resource. Additionally, the Applicant has provided a shadowing/mounding analysis for the installation of clay liners. However, the Reclamation Plan notes (page 5) that lining of the reservoirs is an option only. If the 331Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand_ Gravel and Reservoir Project — M2022-013. Applicant wishes to maintain lining of the reservoirs as an option only, then the Application must be revised to reflect that the reservoirs will be reclaimed to open groundwater ponds. If the Applicant chooses to reclaim the reservoirs to open groundwater ponds, then the following options are available to address the liability associated with exposed groundwater: Rastor Materials First Adequacy Response Please consider the Application Form to be correct and disregard any ambiguity in the application exhibits. Raptor Materials intends to establish lined reservoirs in final reclamation for the purpose of establishing a Developed Water Resource. a) Provide adequate bond to backfill the pit to two feet above the historic highest groundwater level. Raptor Materials First Adequacy Response The application is clarified to reflect choice of lined reservoirs for final reclamation eliminating the need for backfill calculations. b) obtain a court approved augmentation plan prior to exposing groundwater at the site. Raptor Materials First Adequacy Response As the pits will he open ponds until they are lined and approved by the office of the State Engineer, a court approved substitute water supply plan will be obtained prior to exposing groundwater at the site. This is stated in Exhibit E, p4, Specific Reclamation Elements and Methods, third paragraph. 34I Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob ?.ulcer. EPS — Adequacy Letters of 24 June and 5 August 2022, in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Specific Reclamation Elements and Methods: This application provides substantial detail of features utilizing aerial photography that is ortho-rectified to approximately 1.0_ percent of surveyed aceuraci'. This highly accurate and detailed portrayal of planned extraction and reclamation is visible under Exhibit C-1: Existing Conditions, Exhibit C-2: Extraction Plan Map, and Exhibit F - Reclamation Map. How reclamation \ Viil occur over affected lands is further detailed under Exhibit L - Reclamation Costs. As extraction progresses over the Fields south of the Big Thompson River, the resulting 1.25H:1Z- slopes 12H:IV, where indicated) created during extraction will be concurrently modified when and where practical. Concurrent reclamation is a natural incentive for Operations to speed site recovery while generafly serving to lower attending financial warranty burdens. The cut slopes along the extraction limits perimeter will be finished graded by pushing the resulting pit bottom with a dozer until the resulting basin slopes conform with Rule 3.i.&i. Since the primary end use is Developed Water Resources, the basins are intended to hold waters based upon the rights assigned by decree, or as stipulated in regulatory compliance with the Colorado Division of Water Resources, Office of the State Engineer (OSE). This may include the need to augment water sufficient to cover the anticipated exposed groundwaters of the basins in the unlined state. The entireenniinethitasitu is or will be sufficiently covered under an approved substitute supply plan. In order to again liberate waters set aside for augmentation, the basins wil1 at some point in the life of the_ as: be lined to segregate the basin from Colorado groundwaters. Alternatively, the applicant may clarify that the post -mining land use of developed water resource will be achieved through clay lining the reservoirs. If the Applicant chooses to clay line the reservoirs, then the Applicant shall provide enough detail for the Division to calculate the cost to line the reservoirs. Raptor Materials First Adequacy Response The application will be revised to reflect choice of lined reservoirs for final reclamation. Details of reclamation to form lined reservoirs is contained in Exhibit E, pp 4-5, Specific Reclamation Elements and Methods. 35 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Luber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project — fv 2022-0 13. Lining of basins involves the placement of low permeability compactabie fill, from on -site or other suitably sourced geologic materials, into the keyway; the same keyway used to facilitate discharge to keep the basins dry and free of groundwaters at the time of extraction. The balance of the basin floors and slopes are also covered and compacted with the same materials until it meets the standards established under the August 1999 State Engineer Guidelines for Lining VARRA COMPANIES, INC TWO RIVERS SAND GRAVEL_ AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112) CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page IS 6.4.5 EXHIBIT E - Reclamation Plan Criteria. Typical to obtaining approval for the constructed liner, the lined basin must pass a 90 -day leak test. Correspondence from the OSE approving the construction of the lined basin will be submitted to the °MLR on receipt; or as part of any request for release of the permit, in part or whole. Essentially, the pushed parent rock material will form the minimum 3h:Iv slopes of the basin and be compacted to a permeability of IO'b; forming a lined basin that complies with Colorado Water Law and Guidelines mentioned, above. In this manner, the lined basins will maintain a required separation and accounting of stored water from the underlying ground waters. Evidence of compliance with the rules and regulations of the Colorado Division of Water Resources \Oll be provided to the aMLR on completion of the lined basins. Division Second Adequacy Comment RAI must update *E hIbit E to remove ambiguity in the plan in general, al, and in paiaticrilar iii comparison to the application form. Ra for Materials Second Ade uac Res onse The application has been revised as requested with wording revised or removed completely in various revised Exhibits to remove ambiguity and provide clarity that the reclamation plan and proposed post mining land use is lined water storage. 36IPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. ..9) The reclamation plan requires more detail. In particular, the plan should include a schedule that specifies the areas to be reclaimed for given phases, with ranges of time periods. The phases described in Exhibit E should be coordinated with the Reclamation Plan Map, Exhibit F. Raptor Materials First Adequacy Response Refer back to Item #17: We avoid the use of `Phases' to aid simultaneous development of Sections within Fields. The rules provide for clarity in Required Annual Reports and via Revision (Technical. Revisions & Amendments). The goal is to provide flexibility in the document, addressing changes via the Annual Report, and minimize revisions. Division Second Adequacy Comment This item was not sufficiently addressed. Rule 6.4.5 requires details in the reclamation plan. In the e ven t that an operator for wishes fishes to change the plan at a later date. a technical revision or amendment can be employed. Raptor Materials Second Adequacy Response Raptor has revised Exhibit F to provide additional detailincluding discussion and Table E- 1, Mining -Regrading Schedule (p 9, Footnote 5, p10, Footnote 6). 30) The discussion on pit slopes (pages 4 - 5) should include a discussion on the method for grading these slopes, including push distances. Also, the discussion should include the method for verifying the final slopes and documenting this information. Raptor Materials First Adase Final slopes are readily determined using hand-held lasers. Push distances will vary by finished basin depth but are not anticipated to exceed 200 feet but will average significantly less than. this. A Caterpillar D6 LGP or equivalent will be used supported by a compactor. Some material may be dumped in by articulated dump trucks working together with the dozer push and compaction. Division Second Adequacy Comment No additional response is required from RAID 31) The reclamation plan needs to state that all compacted areas will be ripped prior 37IPage Correspondence to the Colorado Office of Mined Land Reclamation —Reply to Rob Zuber, EPS = Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and Reservoir Project — M2022-013. to addition of topsoil and seed. Raptor Materials First Adequacy Response It does: All affected lands between the extraction limits and remaining above the anticipated high-water mark of the basins will be capped with a minimum of six (6.0±) inches of soil, as supported by Lx bit I J - Soils and Vegetation Information. Timing and use of soil are detailed further under Exhibit I & l - Soils and Vegetation information and Exhibit L - Reclamation Costs. Where compacted lands exist, and are to be revegetated, those locations be ripped prior to re- VARRA COMPANIES, INC. TWO RIVERS SAND GRAVE AND RESERVOIR PROJECT MARCH 20) 2 A REGULAR IMPACT 11121 CONSTRUCTION PERMIT APPLICATION = COLORADO DIVISION OF RECLAMATION MDNG & SAFE.Tte OFFICE OF MINED ND RECLAMATK s Page 16 6.4.5 EXHIBIT E - Reclamation Plan soil application. There are no known areas of compaction at the time of this application which would require such activity; and ripping remains a contingency of the application. Division Second Adequacy Comment No additional response is required from RA 32) The reclamation plan needs to include a clear plan for the storage and application of topsoil prior to seeding. The plan should include push distances to the areas and minimum depth. Raptor Materials First Adequacy Response Items addressed under 1120 and #23, should satisfy this concern. Division Second Adequacy Comment ft appears that the extensive discussion on soils does not include any information regarding the quantities of soil in stockpiles or the location of soil piles. This 38 Page Correspondence to the Colorado Office of Mined Land Reclamation —Reply to Rob Zuher, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. in formation is required for a detailed reclamation cost estimate and needs to be added to the Extraction Plan, Exhibit D. Raptor Materials Second Adequacy Response The information requested has been included in revised Exhibit D (p 14, Footnote 2). 33) on page 6, the discussion on seeding should include timing of seeding (and planting if applicable). At what time of year will seeding operations be conducted? Raptor Materials First Adequacy Response Generally, warm and cool seed mixtures can be treated in a myriad of ways. In Table L-1 this distinction is indicated in the column labelled "c/w'". Cool season mixtures are often planted in the fall and warm in the spring, however, exceptions may apply. Some argue warm season grasses are better broadcast, while others like them drilled with the cool season grasses. Division Second Adequacy Comment RAI needs to revise Exhibit I) to address this item and re -submit it. Raptor Materials Second Adequacy Response Raptor has incorporated the First Adequacy response above into revised Exhibit F (page 6, Footnote 3). 34) The weed control paragraph (page 9) should reference the more detailed plan in Exhibit I/J. Raptor Materials First Adequacy Response We understand your preference. Exhibit I/J is an integral part of the application. and the expansion on weeds made self-evident, by virtue of your own acknowledgement that it exists there. There is a significant plan to controlweeds evidenced in both exhibits. We respectfully request the matter be settled as is to avoid needless revision. Division Second Adequacy Comment RAI needs to revise l;tliibit D to address this item and re -submit it. 39I Page Correspondence to the Colorado Office of Mined Land Reclamation = Reply to Rob auger, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Raptor Materials Second Adequacy Response Raptor have provided additional information in response to this request to the Weed Management Plan section in revised Exhibit I/J (page 7, Footnote 2). 35) The Backfill Notice must state the maximum quantity of inert fill that will be stockpiled on the site at any given time. This information is necessary to calculate the required financial warranty amount. Will buildings or other structures be constructed on backfill areas? If so, how will the material be placed and stabilized to prevent settling and voids? Raptor Materials First Adequacy Response Revisiting the Backfill Notice located at the hack of Exhibit E: Reclamation Plan, it is noted that a Backfill Notice is required to address specifics in placement of external materials "generated outside of the approved permit area". The notice in this application however seeks to serve both that purpose and address the use of backfill generated within the 1V1LRR permitted area. The use of on -site fill is from extracted or processed reject materials, field fit at the time, depending upon the state of Operations. This is not predictable, but only inert fill, whether found on -site, or imported, will be utilized. There is no means to forecast fill material produced, but the use and location will be reported in required OMLR Annual Reports and addressed as necessary with adjustment to the financial warranty. This is an established practice with the OMLR from prior operations. As to methodology and avoidance of instability of fill areas, the Notice states: 'All backfill material will be placed with sufficient fines to minimize voids and settling of backfilled areas and slopes. There are no known or expected acid forming or toxic producing materials or refuse at this location, nor will materials known to possess such qualities be knowingly utilized for fill. Any other refuse or reject materials that do not meet the definition of inert and requiring removal and disposal will be placed in closed containers and taken to an appropriate landfill for disposal, unless it is otherwise 'inert,' per Rule 3.1.5 (9) , of the OMLR Rules and Regulations.' Division Second Adequacy Comment \'o additional response is required from x'.-11. hut the Division would like to make (Iii) comments for the record. The purpose of the Backfill Notice is to address imported mater ldl. not material that originates ii-lthin the permit area. Also. if 40 I P a e correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Imported material contains nibble or similar; RA I should handle this material to avoid L-7113 r instability of slopes, 36) The applicant should discuss the following related to the ponds: • The use of very flat slopes (8H:1V) and irregular shorelines in some locations, to allow for diverse habitat. Raptor Materials First Adequacy Response We submit that is in inappropriate for lined basins. Some natural irregularity of man-made structures, easements, and right-of-way, will suffice for edge effect, as will the likely shallower slopes that may form along the sharper edges of the extraction limits,, suggested in Exhibit F: Reclamation Plan Map, if lining is from the basin instead of the perimeter, otherwise, not so much. The purpose of the basin is optimal storage of water, consistent with the stated end use of Developed Water Resources. • The use of constructed islands in the ponds for wildlife habitat. Raptor Materials First Adequacy Response Please see response item "Issue i Water Storage Ponds" prepared by ERO dated August 26, 2022 attached as an addendum to Exhibit H. Division Second Adequacy Comment No additional response is 1 ecjwred 6.4.5 Exhibit F — Reclamation Plan Map 37) The permit boundary is not shown on this map and needs to be added (or the line weight needs to be larger to improve clarity). Raptor Materials First Adequacy Response Exhibit F has been revised. Division Second Adequacy Comment No additional response is required from f1AI 38) A legend should be added to the map clearly showing what the hatching and 41' Page Correspondence to the Colorado Office of Mined Land Reclamation - Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project- M2022-013. other features represent. A yellow box is shown at the southeast corner of the site; please indicate if this symbol represents a real feature or if it is an error. Raptor Materials First Adequacy Response It was shown at a smaller scale to show the effect on the lanclform ecology of the area. A revised 1 inch = an scale map with legend is provided. Division Second Adequacy Comment The issue with the yello u box Was not addressed. Please explain this feature on the flap. Also, please remove the scale in the upper left portion of the map since it appears to be inaccurate. Ra for Materials Second Adequacy Res onse Exhibit F Map has been revised. The purpose of the yellow box was not understood and so has been removed. The scale has been corrected. 39) It appears that the map requires more detail regarding the processing area. Do the topographical lines on Exhibit F accurately show the post -mining topography? If not, the map needs to he updated. Raptor Materials First Adequacy Response Some minor leveling of this area is anticipated to take place however it is proposed to regrade with similar direction and slope to approximate original contour as part of reclamation unless the owner requires otherwise. Division Second Adequacy Comment Please add a text box to the map explaining the topographical lines. If they illustrate pre -mining condltlons, this should be stated. Raptor Materials Second Adequacy Response Exhibit F Map has been revised with labels indicating the processing area will is at `Approximate Original Contour 40) Per Rule 6.4.6, post -mining land uses should be shown on the map. This is especially important for the material processing and wash pond areas. Raptor Materials First Adequacy Response Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Albers. EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Exhibit F has been revised and the primary post -mining land use of Developed Water Resources is clearly evident on the map. Additionally, post -mining land use will be at the ultimate discretion of the owner, also the operator, and is described in Exhibits D and E. Exhibit D, page 2 Commencing on the family farm in 1948, the Varra family combines nearly 73-± years of operational experience that serves as testimony to a history of sound and thoughtfully executed operations of this kind. For the Two Rivers Sand Gravel and Resen-oir Project, lands not otherwise occupied for Developed Water Resources will be improved to the highest possible end -use. Post Extraction Uses beyond the Pr nary Use of Developed Water Resources will likely comprise continuing and diverse general agricultural uses; as well as possible light residential, commercial, or industrial uses; as determined by right. or as otherwise authorized by the governing authority" Exhibit K, p6 Page 6.4.5 EXHIBIT E - Reclamation Plan soil application. There are no known areas of compaction at the time of this application which would require such activity; and ripping remains a contingency of the application. The final land configuration %yill ultimately result in two (2) reservoir basins totaling 234.06± surface acres, with a static water elevation surface area of 217.44± acres (refer to Exhibit F: Reclamation Map). The balance of unoccupied affected lands above the anticipated static water level `-ill be stabilized where necessary utilizing the seed mixture as shown under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. Lands not otherwise occupied for developed water resources will be later developed to the highest possible end -use, and will Likely comprise a mixed use which may include other general agricultural uses as well as light residential, commercial or industrial uses. Division Second Adequacy Comment RAI needs to revise EZliibit F and re -submit it. As appropriate, the language included in the response letter from RM should be added to the map in a text box or in notes in the title block 43 I P age correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project - M2022-013. Raptor Materials Second Adequacy Response Exhibit F Map has been revised as requested. Labels have been added indicating the regraded and lined excavations are "Developed Water Resources with Grass Embankments", and an explanatory note added adjacent to the Legend. 41) Several structures and easements are shown on Exhibit C-1, and none are shown on Exhibit F. Please explain if all of these structures will be removed during the mining and reclamation operations. Raptor Materials First Adequacy Response Please refer to iesponse to Item 18. Division Second Adequacy Comment Please confirm that Exhibit F is accurate. Are all above ground and underground structures that will ' remain after mining is complete shown n on the map? Raptor Materials Second Adequacy Response Raptor has confirmed in revised Exhibit H that Exhibit F presents Raptor Material's current expectation of the remaining above ground and underground structures within Affected Area at the point the reclamation of mining related disturbance is complete (page 8, Footnote 4). This is also explained in a note on the Exhibit -F map. 42) The Division recommends adjusting the scale on this map. The current version includes considerable area that is beyond the permit boundary. Raptor Materials First Adequacy Response It was shown at a smaller scale to show the effect on the landform ecology of the area. A revised 1 inch = 200 scale map with legend is provided. Division Second Adequacy Comment No additional response is required from RAt. 6.4.7 Exhibit G - Water Information 43) On Page 1 of Exhibit G, the text states that the site will drain internally. Please add a statement that the site will be operated to prevent any significant runoff from 44I Page Correspondence to the Colorado Office of Mined Land Reclamation - Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. disturbed areas from flowing offsite. Also state that the site will be operated t o prevent any negative impacts to the hydrologic balance of the two rivers. Raptor Materials First Adecuacy Response We are not required to Prevent,' but rather `Minimizeimpacts. We believe the submittal conservation measures and provisions attain this standard. Rule 3.1.6 "Disturbances to the prevailing hydrologic balance of the affected land and of the surrounding area and to the quantity or quality of water in surface and groundwater systems both during and after the mining operation and during reclamation shall be minimized by measures, ..." Considerable efforts are made to control storm flows, including the use of grassed waterways. Some rifling will occur on cut slopes, but the sediment is inbound. A minor 6 -inch furrow above cut slopes will create a 1 -foot scale that could minimize such tilling, especially valuable on reclaimed slopes above the final estimated water level of the basins. The storniwater management plan referenced in Exhibit I &a J will address broader ater management covering the material processing area and any piles of soil or inert fill constructed external to the excavations. Division Second Adequacy Comment The Division agrees that the bi ord Il11111.171Ize " is appropriate. rather than "prevent." Howe i rer, RAI needs to revise Exhibit G and re -submit it. Exhibit G should include the statements requested 111 the original adequacy letter (using the Ti Ord "minimize as noted above). Raptor Materials Second Adequacy Response Raptor has revised Exhibit G as requested (page 1, Footnotes 1 and 2). 44) Describe the physical dewatering system and provide a description of the operation of this system. A copy of the discharge permit application provided to CDH is included with this submittal. It will indicate information about the pump capacity and discharge rates. Exhibit D: Extraction Plan devoted a section to it, and AWES devoted a report to it, as provided with the other attachments in this reply. Here's what the permit 451Pag,e Correspondence to the Colorado Office of Mined Land Reclamation -- Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project - M2022-013. application stated, followed by a blow-up of the feature visible near the #10 Piezometer, under Exhibit G: Water Information Map: ( 13 6.4.5 EXHIBIT D - Extraction Plan preferred native seed mixture offers opportunity to gauge the potential performance of the selected species prior to utilizing it over larger areas requiring reclamation later in the life of the resource recovery operation. Once vegetation is established over the initial reclamation soil stockpiles, they will likely remain untouched for the life of the operation until final reclamation of remaining affected lands takes place. Where concurrent reclamation is possible, operations will utilize soil in an over the shoulder method when practical. In this manner, reclamation is expedited without increasing soil stockpile volumes while reducing expenditures related to labor, handling, and time. Dewatering: As extraction activity, progresses into the aggregate profile, groundwater must generally be removed in advance through the use of pumps and subsequent discharge into area tributaries. A complete dewatering evaluation was performed by AWES in their report of 27 July 2020, as provided at the back of Exhibit G: Water Information. The report concludes that 'the results of analytical and numerical solutions indicate that the proposed mine dewatering activities will not adversely affect the regional groundwater hydrology.' The reader is further assured that all discharge of waters will be conducted under an approved CDH discharge permit. Initial dewatering of the property in preparation for extraction and resource recovery will occur by establishment of a dewatering pump and/or well in the Southern boundary near an existing agricultural pond. The point of discharge is on Exhibit G: Water Information Map. Other discharge locations may occur in time as needed and otherwise approved under the applicable CDH discharge permit requirements. Subsequent CDH approved discharge locations will be field fit and the location updated in the following OMIJR Annual Report. 46 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber., EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project —M2022-013. Division Second Adequacy Comment Please acid to Exhibit G a SL1171177a1 1 ' of the s.j -ster Tt 1th references to other exh.rbits and other documents (e.g.. the Water Qualio. . control Division application), as appropriate. Raptor Materials Second Adequacy Response Revised Exhibit G now references clearly the extensive discussion on dewatering in Exhibit D (page 6, Footnote 10). 45) The Water Information exhibit should provide a detailed discussion of floodplain management at the site. This must include a discussion of the conveyor crossing of the Big Thompson River. It should also reference the Floodplain Permit report by Headwaters Corporation, as appropriate, Raptor Materials First Adequacy Response Operational elements of floodplain management are clescrbecl in Exhibit Exhibit D, p6 47 P a L2 c Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob .tuber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Wetland conditions appear confined within portions of the stream terrace and band -full stage of the rivers, and along segments internal to the Evans Canal. Extraction will form a depression (basin) within the floodplain as shown in Exhibit C-2: Extraction Plan Map. Temporary above ground fill may occur within the floodplain, and as part of this permitted activity, provided the above ground volume does not exceed the bel* ground volume created by extraction. All product stockpiles and processing will occur within the city limits of Evans under this application, and North and outside of the floodplain boundary of the 100 -year floodplain of the Big Thompson River. The floodpiain extent will be visually marked in the field to bitter assure the integrity of the floodplain_ Material transport of raw materials from extraction locations to the plant site will occur via conveyor (see route on Exhibit C-2: Extraction Plan Map). This will in turn serve to minimize impacts to area transportation corridors. The actual location, extent, and nature of the conveyor systems not otherwise designated in this submittal will be provided as updates in the required ONILR Annual Reports. As described in this response concerning items 23 and 24, additional detail on the floodplain management and the conveyor was stated as follows: From Item 23 Response We can affirm here that stockpiling above the existing ground elevation will not occur in a manner understood to obstruct flood waters where they might occur within the existing floodplain. It is understood and agreed here -in that their longitudinal dimensions if they occur there should extend parallel to anticipated flood flows where they exceed a cone or other shape that might find its existence contrary to intent by volume beyond that which could be understood to be temporary, or transitory; especially outside of seasonality where flooding might be more reasonably anticipated. From Item 24 Response The conveyor will be set on an elevated structure at varying heights to be situated about the 1 in 100 -year flood level. An average height of 7 feet is expected. The conveyor will be supported by legs at intervals of approximately 20 feet with concrete blocks used as necessary to anchor the legs. Final conveyor specifications are to be determined but a 24-36" belt is anticipated. A wider span than typical will cross the Big Thomson River at an elevation above 48j Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project -- M2022-013. the 1 in 100 -year flood level. Division Second Adequacy Comment • The text provide in the RM response that explains floodplain management at the site must be added to Exhibit G. As noted above, Annual Reports should not to be used to make changes to the mining and reclamation plans, including thelocations of structures. Those changes must be made with technical revisions and amendments. • Please explain the relevance of the Headwaters Corporation report included in the original submittal. Raptor Materials Second Adequacy Response Raptor has revised Exhibit G as follows: • Raptor's First adequacy response that explains floodplain management at the site has been added to Exhibit G (page 3, Footnote 6). • Acknowledged. • The relevance of the Headwaters Corporation report included in the original submittal is discussed (page 4, Footnote 7). 46) To ensure that the Two Rivers project minimizes impacts to the hydrologic balance of the rivers, the application needs to include a water quality monitoring plan, specifically for the alluvium. [see Section 20 — Exhibit G in -Adequacy Response] The groundwater monitoring plan should be developed in accordance with Rule 3.1.7(7)(b) and should include a Quality Assurance Project Plan (QAPP) for the collection of groundwater samples. The plan should provide mitigation steps if there is an exceedance dance at a groundwater or surface water monitoring location. Potential impacts to quality and/or quantity the nearby domestic wells should also be addressed. A copy of the Division's Groundwater Monitoring and Protection Technical Bulletin has been included as an enclosure to this letter for your reference. Raptor Materials First Adequacy Response This was an oversight. Please refer to AWES Report, #2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment 49IPage Correspondence to the Colorado Office of Mined Land Reclamation - Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. A water quality monitoring plan is required for this permit. Please develop that and Include in the revised Exhibit '. Raptor Materials Second Adequacy Response A Groundwater Monitoring Plan has been prepared by consultant AWES and is provided as an additional addendum to Exhibit G (page 4, Footnote 8). 47) Change "NPDES" to "CDPS" S" to reflect the requirements of the Water Quality Control Commission. Raptor Materials First Adequacy Response Acknowledged and noted that our only reference to NPDES was simply incorporating text directly from the rules. Please see Prologue. Division Second Adequacy Comment No additional response is required from Ri1I. Exh H - Wildlife 48) Indicate which recommendations on wildlife protection in "Threatened and Endangered Species Habitat Assessment, Two Rivers Parcels" (EEO, 2022) will be implemented at the site. This report was submitted with Exhibit II of your application. Raptor Materials First Adequacy Response Please see response item "Issue - Wildlife Protection Recommendations" prepared by ERO dated August 26. 2022 attached as an addendum to Exhibit H. Division Second Adequacy Comment No additional response is' required 11 O111 11111. Exhibits la 49) This exhibit should include a discussion on wetlands in the project area, including the wash pond and material processing areas. Please state that operations will be conducted to minimize impacts on wetlands or state that no operations will be conducted in wetland areas. Raptor Materials First Adequacy Response 50 Pa e Correspondence to the Colorado Office of Mined Land Reclamation = Reply to Rob Luber. EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Under Exhibit M is an approved U.S. Army Corps of Engineers report designating 'No Permit Required.' Most of the wetlands as they occur at the Big Thompson River are predominantly limited to the channel itself. If and when a conveyor is built upon the projected line, the footings are not expected to exceed the requirements for a Nationwide Permit, but if they will, a Nationwide Permit will be applied for and secured prior to affecting such areas. It simply isn't anticipated at this time. If a Nationwide Permit is necessary, the ()MLR will be provided with the necessary justification or approval under an ONILR Technical Revision to that end. Please refer to Item #45 for additional clarification. Division Second Adequacy Comment R I needs to revise Exhibits /i, and re -submit, with the discussion and statement regarding m1n1n11zatl on of impacts. As appropriate. te. reference other exhibits and reports from other entitles (e.g., the LTS Al??11 Corps of Engineers), Raptor Materials Second Adequacy Response Raptor has revised Exhibit DI as requested (page 3, Footnote 1). 50) In the Weed Management Plan, the paragraph that mentions the State of Colorado noxious weeds list should state that List A species will be eradicated and List B Species will be controlled. The plan should also describe the efforts that will be made to control List C species, including field bindweed, a focus in Weld County. The Division recognizes that mapping and vector identification can be useful tools for weed control, but these practices should not delay treatment of weeds. Raptor Materials First Adequacy Response Weed management will be under the supervision of a certified weed management specialist. All applicable requirements currently in force at the time will be adhered to. Division Second Adequacy Comment l�jr1 did not address the adequacy item. RA1 needs to revise Exhibits is El and .re submit. t f 7th the s to tem7men is regarding listed species. Raptor Materials Second Adequacy Response Raptor have provided additional information in response to this request to the Weed 511Pa e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Management Plan section in revised Exhibit 1/J (page 7, Footnote 2). 6.4.12 Exhibit L - Reclamation Costs 51) This exhibit should be updated, as necessary, to match any revisions to Exhibits D and E, per the adequacy items for those sections. This includes details on structures. Raptor Materials First Adequacy Response RM has reviewed Exhibit L and believes it adequately reflects changes to Exhibits D and E. Division Second Adequacy Comment 117 the context of this second adequacy letter, Exhibit L must be updated to reflect revisions to Exhibits D and E Raptor Materials Second Adequacy Response A substantially revised Exhibit L has been prepared as requested. 52) The cost estimate should include a task for ripping areas that will be topsoiled and vegetated. Raptor Materials First Adequacy Response An allowance could be made for ripping a percentage of the area assuming it becomes compacted. Division Second Adequacy Comment RAi did not address the adequacy item. RM needs to revise Exhibit L to include the ripping task. Raptor Materials Second Adequacy Response Raptor has made appropriate allowances for ripping (disking/scarifying) as requested in revised Exhibit L (page 8, Footnote 3; page 9, Footnote 4). 53) The Applicant has noted under the Reclamation Plan (page 5) that water shares will be dedicated to the Division of Water Resources CDWR) to cover the liability associated with exposing groundwater. Please be aware that the Division no longer 52 ' P a g e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob ?uber. EN — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project M2022-013. accepts the dedication of water shares to DWR as a bonding mechanism. The Applicant will need to post a financial warranty to allow for backfilling the areas of exposed groundwater or a financial warranty to cover the cost of installing clay liners in the reservoir. Please see additional comments under Item No. 29. Raptor Materials First Adequacy Response Raptor has confirmed and will amend the application to state that Developed Water Resources will be the post -mining use for the pit excavations and will provide financial warranty appropriate for cost of constructing lined pits. Division Second Adequacy Comment No additional response is required from RAI 6.4.13 Exhibit M Other Permit and Licenses 54) Please commit to providing copies of all required and approved permits and licenses to the Division when available. This should include well permits and documents related to water rights, such as a Substitute Water Supply Plan. Raptor Materials First Adequacy Response Raptor affirms copies of all required and approved permits and licenses will be obtained and provided before actions requiring permits commence. Division Second Adequacy Comment No additional response is required Iron] R I. 6.4.14 Exhibit N - Source of Legal Right to Enter 55) This document must show that Raptor Materials LLC (rather than Varra Companies, Inc.) has the legal right to enter lands under this permit. Raptor Materials First Adequacy Response The exhibit is updated and attached. Division Second Adequacy Comment No additional response is required Pro 177 RAI. 6.4.18 Exhibit R - Proof of Filing with County Clerk and Recorder 53 Pt C Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. 56) Please provide an affidavit or receipt indicating the date on which the revised application information required to address this adequacy letter was placed with the Weld County Clerk. Raptor Materials First Adequacy Response An updated affidavit is provided and attached as Exhibit R? Division Second Adequacy Comment No additional response is required from RAI 6.4.19 Exhibit S - Permanent Man-made Structures 57) The Division requires Raptor Materials LLC to demonstrate that they attempted to obtain notarized structure agreements with all owners of the structures within 200 feet of the affected area of the proposed mine site, pursuant to Rule 6.4.19. This attempt must be made prior to the Division's consideration of a stability analysis. Please also indicate what agreements have been obtained. Raptor Materials First Adequacy Response This information was provided earlier via Susan Bergmaier submittal of Notifications, with the signed versions of an agreement sent to all owners of structures known to us. Division Second Adequacy Comment • Rill needs to update Exhibit S u nth all relevant 1n.torrnatlon Including.. o sA list of all structure o wnerg, o :A list of agreements obtained from these owners. Raptor Materials Second Adequacy Response Exhibit S has been revised as requested (page . Footnote 1). 6.5 Geotechnical Stability Exhibit 58) The Division has reviewed the Slope Stability Analyses (prepared by AWES, LLC), and our comments are provided as an enclosure with this letter. Please review this memorandum and provide responses. Raptor Materials First Adequacy Response Please refer to AWES Report dated August 10, 2022, now appended to the 54 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Tuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Tw\ o Rivers Sand, Gravel and Reservoir Project — M2022-013. Application as an addendum to Exhibit S. ivision Second Adequacy Comment No additional response is required from R I 55 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project -- M2022-013. The Division is still reviewing two of the technical reports associated with this application: "Riverside Berm Failure Analysis and Flood Control Mitigation Plan" (Flow Technologies LLC, 2020) and "Dewatering Evaluation, Varra Two Rivers Mine" (AWES LLC, 2020). Division comments and questions related to these reports will be sent under separate cover. August 05 2022 - Additional reviews for preliminary adequacy Flood Control Mitigation Plan Raptor received additional comment on this aspect of the application November 17, 2022 and will respond separately on this issue. 1) i-Lydrograph Development: Paragraph 3.2.3 indicates the 10 -year flow was subtracted from the inflow hydrograph because "it is estimated the earthen berm will control a 10-yr flood event". This does not seem to be a straight forward assumption. If the entire site is to be flooded, it seems the water elevation of the flood above the berm elevation would he the controlling flow parameter, much as a hydrograph routed through a reservoir controls the depth of overflow in a dam overtopping failure analysis. Please provide some background on why this assumption is reasonable. Raptor Materials First Adequacy Response Please refer to Flow Technologies Report dated August 27, 2022, now appended to the Application as an addendum to Exhibit G. 2) Hydrograph proportionment: Paragraph 3.2.3 references FEMA, Flood Insurance Study, January 20, 2016 as validation for having two-thirds flow through the south side of the Site (central Field) and the remaining one third flow through the north side of the site. Please: a) Elaborate on the purpose of splitting the flows, b) Explain if this is used directly in the WinDAM C berm failure analyses or n the hydrograph development for determining water elevation, or somewhere else, c) Explain how it impacts the approach and results (e.g., how sensitive is the analyses to this 2/3 ratio) Raptor Materials First Adequacy Response Please refer to Flow Technologies Report dated August 27, 2022, now appended to the Application as an addendum to Exhibit G. 3) Hard Armoring: Both paragraphs 3.2 and 4.2 reference Section V, Hard Armoring. 5r6IPage Correspondence to the Colorado Office of Mined Land Reclamation - Reply to Rob Zuber, EPS - Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project - M2022-013. Section V is labeled Mitigating Measures and does not discuss any hard armoring. Please provide some discussion on the anticipated hard armoring for reclamation closure. Raptor Materials First Adequacy Response The Flow Technologies January 2020 report indicated both that the riverside berms under conservative assumptions should withstand breach due to head cutting in al in 100 year flood event, however suggested that "the pit locations most susceptible to head cutting will be armored"(Section 3.2), or more specifically in Sections 3.6 and 4.2, hard armoring is discussed as a reclamation practice in the areas or locations (most) susceptible to head cutting. it should be understood that the head cutting modelled did not result in breach of 100 -feet berms although berms are assessed as varying in width from 100-150 feet. Additional conservatism included in the modeling included inundation from a storm event which would be worst case with little warning allowing pit dewatering to be temporarily halted and reducing pit fill time, assuming the event occurs when the pits are fully excavated, resulting in maximizing fill time, and that there is no vegetation with increases the rate of erosion. The mitigating measures described in Section V state that "should a flood occur that results in head cutting/erosion of a riverside berm, Varra Companies, Inc. [now Raptor Materials] will immediately restore the damaged area to pre -flood conditions.". This is in effect. "reclamation" of the berms. This however does not preclude RM implementing measures to reduce the impacts of head cutting or likelihood of berm breach including establishing or maintaining vegetation, and hard armoring (riprap). Such measures, particularly hard armoring would be considered in the areas or locations most susceptible to head cutting, i.e. where berms are narrower. Should such measures be taken as preventative rather than restorative (reclamation), properly installed engineered riprap, (size and thickness calculated) would be assessed at the time. 4) Variable Water Surface Elevation: As expected for a river flood and depicted in Figure 8, the water surface elevation varies from the upstream to downstream segments of both rivers. The DRMS' understanding of WinDAM C is that it assumes a uniform flow elevation over the embankment being analyzed. How is the fact that the water elevation is not uniform in this scenario accounted for in the modeling? Raptor Materials First Adequacy Response 57IPage Correspondence to the Colorado Office of Mined Land Reclamation —Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand. Gravel and. Reservoir Project — M2022-013. Please refer to Flow Technologies Report dated August 27, 2022, now appended to the Application as an addendum to Exhibit G. 5) Fill Time Estimates - Central Pit: The fourth column in table on p. 30 suggests a nearly uniform incremental delta for every 10 feet of pit depth. This suggests the pit being analyzed for a depth/storage relationship has nearly vertical side walls. Are the pit walls in the berm failure scenarios being analyzed vertical and is this condition reflected in the WinDAM C analyses? Raptor Materials First Adequacy Response Please refer to Flow Technologies Report dated August 27, 2022, now appended to the Application as an addendum to Exhibit G. 13) Central Pit Groin Training Channels Calculations: on p. 41 is a Mannings normal depth flow calculator for a 25 -foot bottom width with 1H:1V side slopes. It is unclear as to the purpose of this image. Eased on the Mannings n = 0.025, it would appear this is likely an earth -lined channel. As such, a 1H:1V slope is not likely to be stable for long. Please indicate the purpose of this image and justify the channel geometry depicted in it. Raptor Materials First Adequacy Response Please refer to Flow Technologies Report dated August 2/, 2022, now appended to the Application as a supplement an addendum G. 7) HEC-RAS Output: Several of the HEC-RAS cross section output results indicate additional cross -sections may be warranted: a) The conveyance ratio (upstream conveyance divided by downstream conveyance) is less than 0.7 or greater than 1.4. This may indicate the need for additional cross sections. b) Warning: The energy loss was greater than 1.0 ft (.0.3 m) . between the current and previous cross section. This may indicate the need for additional cross sections. Please provide rationale for not including additional cross sections. Raptor Materials First Adequacy Response Please refer to Flow - Technologies Report dated August 27, 2022, now appended to the Application as an addendum to Exhibit G. 58I Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob tuber, CPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project - M2022-013. Additional Comments on Groundwater (AWES Dewatering Evaluation) Exhibit G General 1) The proposed text of Section 6.4.7, Exhibit G, allows for the post -mining lining of the pits but does not commit to it. It is not appropriate for the Division to approve a contingent reclamation plan; the approved text should describe a single reclamation plan. If the decision is made at a later date to change the plan then an amendment application should be submitted at that time. Please revise the text. of Exhibit G to describe the post -mining plan for the lining or otherwise of the excavated pits. Raptor_ Materials First Adequacy Response Please refer to Flow Technologies Report dated August 27, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The response is sufficient - the plan is to line the pits. 2) The text also refers to "OMLR" in places, which presumably stands for "office of Mined Land Reclamation". This office does not exist in Colorado. Please replace any reference to "OMLR" in the text with "DRMS". Raptor Materials First Adequacy Response Acknowledged. Please see Prologue. Division Second Adequacy Comment The response is sufficient - the applicant has elected to continue to use "O:11L.R" " with justification, despite the fact that the term is deprecated. 3) Water level data from piezometers P124-1 through P124-12 has been given in the text of Exhibit G but the locations of the piezometers are not shown on Exhibit G: Water Information Map (or Exhibit C-1: Existing Conditions Map). Please add the piezometer locations to Exhibit G: Water Information Map. Raptor Materials First Adequacy Response Please see revised Exhibit G Map. Please note there is considerable detail presented on the map and it may be necessary to either print at scale or zoom to see the information. 59 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zubcr, EPS v Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Division Second Adequacy Comment Plezorneter locations have been shown on the updated version of -vvhlblt Water Information Map, hO11.e ver they are labelled using a different flail;ing convention (see fiz; ure 1). Please label the piezom'etel s on the map as they are referred to in the text of the AWES s tu.d j Raptor Materials Second Adequacy Response A revised addendum (10) to Exhibit G is attached with the piezometer names corrected and now aligned with the Exhibit G map. 4) The key of Exhibit G: Water Information Map shows a symbol for wells, but no wells are identifiable on the map. It's not clear whether they were omitted or are not legible. Please identify all registered wells on Exhibit G Water Information Map. Please also add a table to section 6.4.7 with details of these wells including their permit IDs, owners, date of construction and registered use. Raptor Materials First Adequacy _ Response Please see revised Exhibit G Map. Please note there is considerable detail presented on the map and it may be necessary to either print at scale or zoom to see the information. Division Second Adequacy Comment Please rdentlfj, all registered wells on Exhibit G: Water Information Map. Please also add a table to section 6.4. i with details of these wells including their permit IDs, owners, date of construction and registered use. Raptor Materials Second Adequacy Response A table of wells has been compiled and added to revised Exhibit G map and as an addendum to Exhibit G (page 3, Footnote 5). 5) Exhibit G: Water Information Map shows several symbols that are not included in the map key, and the text in many of the labels on the map is illegible (including what are presumably stream stage elevations). Please revise Exhibit G: Water Information Map to improve its legibility and to provide a complete key for map symbols (it may be helpful to remove the aerial 60 age Correspondence to the Colorado Office of Mined Land Reclamation a Reply to Rob Zuher, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-01 3. imagery base -map). The revised map should be prepared and signed by a registered land surveyor, professional engineer, or other qualified person, as is required by Rule 6.2.1(2)(b). Raptor Materials First Adequacy Response Please see revised Exhibit G Map. Please note there is considerable detail presented on the map and it may be necessary to either print at scale or zoom to see the information. We have found either provides legible information. Division Second Adequacy Comment Please revise Exhibit G: Water ter Information Map to impl y ve its legibility and to provide a complete key for map symbols (it may be helpful to remove the aerial imagery base -map). The revised sed map should be prepared and signed by a registered land surveyor ; professional engineer or other qualified person, as is required by Rule 6.2.1(2)(b). (I1'7th reference to the updated version of Exhibit G: Water- Information Map): R -hen the pelf of the map is viewed at 300% zoom most of the labels are legible (except ii her e the i = are obscured by other map elements). ho U re ver this level of ZOO!?? makes the map very difficult to use. Several symbols are used on the map but are not identified in the key or labelled on the map, these include: Inverted red triangles (as shown in figure 1) 4 Bold red lines and squares (as sho II77 in figure 2) l ello w highlighting Oil contour lines (as sho Ii I1 in figure ) • Dashed brown line (as shown rn in figure 2) • Y ello I-FF polygons (as shown in figure , ) Blue marks (as shown 111 figure 3) Fine dashed red lines (as sho 14 I1 1n fig urn' 3) • Light red dots (as shown in figure 3) • Black triangles (as sho TI 71 112 figure 3) The map has not been signed, stamped. or otherwise certified by a registered ster'ed land survej 'or. professional engineer : or other qualified person. 61 (Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. In (54. i(1) the statement is made that ;'Operations will not adversely affect surface and groundwater systems". In support of the statement, the text refers to a July 2020 s tucl j - b.T . American Water Engineering Services, LLC of Fort Collins. CO (A M%1$ 20202 American Water Engineering Services, LLC was formed in 2011 and is currently in good standing with the Colorado Secretary of State's office. The A R'ES 2020 report presents a hydrogeo/ogic evaluation based on a numerical groundwater flo ll - model built with Visual ModFlo w Pro, an industry standard r;r_ round uater flow 111Odelrng code. Background Inion 'atlon is given in the report, followed hy assumptions, model parameters, results and conclusions, Figures and plates are appended to the report. Bit its nature a numerical car ound a ater flo TT- model is a simplification of the real system and is built using a series of assonip[ion s and compromises on the part of the modeler with the goal of answering pertinent questions about the system. The questions that the AWES 2020 model seeks to answer are not specifically defined, but are generally stated as "to estimate the effects of dewatering operations on tliey Surrounding gro un d wa ter ki -drol og v ' . In MY revie e I t - of the AWES 020 model 1have tried to a void "nit picking " but u look first at the overall validity i of the conclusions that can be dra II72 from it, and then to evaluate whether those conclusions support the statement that "Operations will not adversely affect surface and groundwater systems". Questions 6 through • • • hello (V are asked to help the Division better- understand the model. Raptor Materials Second Adequacy Response Exhibit G map has been revised as requested with the minor drawing artifacts removed for clarity. Exhibit G - AWES Dewaterin Evaluation 6) Key assumptions of the model are that the aquifer is unconfined, homogenous and anisotropic, with a horizontal hydraulic conductivity (Kh) of 125 ft/day and a vertical hydraulic conductivity (Kv) of 12.5 it/day. The K values are at the lower end of the expected range of 2000-100 ft/day (Robson, 1989). Please ,justify the assumption of anisotropy and the chosen K values for the sand and gravel aquifer. Raptor Materials First Adequacy Response Please refer to AWES Report, #2022-RM-P124 4 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. 62IPage Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter or the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Division Second Adequacy Comment Seec O171;77 eln t O17 hem 7. 7) The piezometers referred to in (O) are described as monitoring wells in AWES 2020. Please describe how these wells were used for pre -mining aquifer characterization (besides the collection of water level data) . Raptor Materials First Adequacy Response Please refer to AWES Report, #2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The response to 6 and 7 is sufficient - the author has assumed aquifer properties based on his prior experience of similar geologic settings. Although the assumed hydra ulrc conductivity values seem reasonable with th respect to the literature, it is a notable weakness of the A + ES study that the opportunity - Wasn 't taken to use the constructed monitoring wells to conduct any field tests of aquifer properties. There are many published equations linking hydraulic conductivity and grain size of the form "K is proportional to dlO since it was first proposed in the 1890s, but they are of doubtful validity, are generally only employed r lien other methods of estimating hydraulic conductivity are not available, and the value of the proportionality r constant is usually emplricall j derived - 1171 not a ut are of any justification for assuming a proportionality constant of 1, and none has been presented, (Hazel)! 1892; Eggleston. 2001.' carrier. 003.). 8) No information is presented about the vertical extent of the model. How many vertical layers are used in the model? What are the layer thicknesses? Raptor Materials First Adequacy Response Please refer to AWES Report, #2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment 63 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. The response is suf cien t - there are two vertical layers in the model with the upper layer representing unconsolidated alluvial deposits and the 10 ii er 1aj er representing bedrock. ) No information is presented about recharge from precipitation. Is recharge from precipitation accounted for in the model, or is its impact assumed to be negligible? Raptor Materials First Adequacy Response Please refer to AWES Report. #2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment .the response is sufficient - a 1.5 inch recharge rate was assumed. 10) The Mine Area Map presented as Figure 2 shows a different pit configuration from that presented elsewhere in the permit application packet (PAP) - it shows three pits, whereas Exhibit : Water Information Map, for example, shows just two. The Model Boundary Conditions presented as Plate 1 reflect the configuration shown in Figure 2. Please discuss the validity of the model boundary conditions in the light of the final pit configuration (which is assumed to be that shown on maps in the PAP). Raptor Materials First Adequacy Response Please refer to AWES Report, #2022 -Rail -P 124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The response is sufficient - the model houndap- conditions were updated try correspond espond more closely to the t Ti o pit conhigura i f on sl o TF rri else where in the mine plan. 11) According to the literature, water table gradients in the alluvial aquifers of the region are typically in the range 0.002 to 0.007 (Arnold, Langer & Paschke, 2003). The water table contour map presented as Plate 3 shows a generally easterly gradient of 0.002 across the center of the proposed permit area. A single data point (MW -1, which is presumably the same as P124-1) exists north of the Big 64I Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. Thompson River, with a significantly higher water level. This distorts the water level contours in the north of the study area, suggesting a far steeper gradient (0.01) and a south-easterly flow direction. Please discuss the characterization of the pre -mining water table. How reliable is the data from MW -1? How do you account for the steeper gradient? Are there any other data points in the north of the study area to improve the characterization? Raptor Materials First Adequacy Response Please refer to AWES Report, 2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The response is sufficient - the author has used the available data to characterize the site a's thoroughly as possible. 12) The model was calibrated using model -assigned observation wells outside of the proposed excavations, (presumably the points shown with green and white symbols on Plates 6 and 7). The first two sentences of the final paragraph on Page 3 of the AWES 2020 report suggest that water levels were measured at these locations, but I think that these are simulated wells. Plates 5 and SA show the calibration results. They appear to show identical data. Water level contours showing initial conditions in the calibrated mocel are presented as Plate 4. The contours suggest a gradient of 0.06 to the SSE in the north of the study area. Please clarify the initial calibration process. Please discuss the validity of the model in the north of the study area. Raptor Materials First Adequacy Response Please refer to AWES Report, #2022-RM--P 124 dated August 31, 2022, row appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The response is sufficient - the author thoroughly described the model calibration process. 13) The results of the dewatering simulation are presented as Plate 6. This is presumably a steady state simulation. It simulates dewatering of the central and 65 P a g e Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Luber, EPS — Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. north-west pits only. Please simulate the dewatering of the full extent of the mined area. Please estimate the time to achieve steady state conditions. Raptor Materials First Adequacy Response Please refer to AWES Report, 1/2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The steady state X11 a u -do 1F n scenario is presented on Plate 7. In the Conclusions section of the report the author states: "The predicted dra rdoTT7i associated 111th the n-ilne dewatering lng represents the worst case scenario and a substantial amount of time will be required be_fore lnaxi x111171 c/l a 1vdo Tins Will occur Please estimate the aziiount of time. based on model results, for maximum dr a vrdo TF rns to occur. Raptor Materials Second Adequacy Response This was an oversight from the First Adequacy response and has been addressed in revised Exhibit G supported by a August 30, 2022 letter report from AWES, LLC now added as an addendum (page 2, Footnote 3). 14) Table 1 presents the predicted water levels at the 4 simulated wells before mining and following the lining of the mined pits. Please add a column to Table 1 showing the predicted water levels under the pit de -watering scenario. The table should show the fullest extent of the potential drawdown caused by the mine operation. Raptor Materials First Adequacy Response Please refer to AWES Report, #2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment Me response is sufficient - Table 1 shows maximum predicted dl a It oro Wns at the simulated wells. as TTrell as the predicted post -pit -lining TT "a ter elevation. 15) In the conclusions section on Page 4 of the report, the statement is made that "The results of analytical and numerical solutions indicate •••" however no analytical tical analytical � � �� T F r T I 66 Page Correspondence to the Colorado Office of Mined Land Reclamation —Reply to Rob Zuber, EPS — Adequacy Letters of 24 June and 5 August 2022: in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. solutions are presented. Please update the report to present any relevant analytical solutions that support the conclusion. Raptor Materials First Adequacy Response Phase refer to AWES Report, #2022-RM-P124 dated August 31, 2022, now appended to the Application as an addendum to Exhibit G. Division Second Adequacy Comment The response is sufficient - analytical solutions are used earlier in the report. RAPTOR Nil ATERIAUtic Garrett C. Varra, General Manager 67 Page Correspondence to the Colorado Office of Mined Land Reclamation — Reply to Rob Zuber, EPS Adequacy Letters of 24 June and 5 August 2022; in the matter of the Two Rivers Sand, Gravel and Reservoir Project — M2022-013. COLORADO Division of Reclamation, Mining and Safety Department of Natural Resources October 17, 2022 Bradford Janes Raptor Materials LLC 8120 Gage Street Frederick, CO 80516 Re: Two Rivers Sand, Gravel and Reservoir Project, File No. M-2022-013, 112c Permit Application, Second Adequacy Review Mr. Janes - The Division of Reclamation, Mining and Safety (Division/DRMS) reviewed the contents of the 112c permit application for the Two Rivers Sand, Gravel and Reservoir Project (TRP), File No. M- 2022-013 and submitted preliminary adequacy letters on June 24, 2022 and August 5, 2022. We received responses to these items from Raptor Materials LLC (RM) on September 6, 2022. The Division is required to issue an approval or denial decision no later than November 4, 2022, therefore a response to the following adequacy review concerns should be submitted to the Division as soon as possible, or another extension will be required. The review consisted of comparing the application contents with the specific requirements of Rules 1, 3, 6.1, 6.2, 6.4 and 6.5 of the Minerals Rules and Regulations of the Colorado Mined Land Reclamation Board for the Extraction of Construction Materials (effective date July 15, 2019). Any inadequacies are identified under the respective exhibit heading along with suggested actions to correct them. As applicable, the Division requests that RM revise actual exhibits and re -submit them. It is not sufficient to provide clarifying language in an adequacy response letter. The following items are listed by numbers that correspond to the original items in our June 24 letter. New comments are in bullets and italic font below the original adequacy items. 1313 Sherman St. Room 215 Denver, CO 80203 P (303) 866-3567 F (303) 832-8106 htt ps: / / drms. colorado. gov Jared Polis, Governor Dan Gibbs, Executive Director I Virginia Brannon. Director Bradford Janes October 17, 2022 Paget General Comments 1) On May 18, 2022, the Division approved a transfer of the Two Rivers Sand, Gravel and Reservoir Project 112 Application from Varra Companies, Inc. to Raptor Materials, LLC. Please provide a letter from Kevin Jeakins (as part of your response to this adequacy review) stating that Bradford Janes is authorized to act as a permitting representative of Raptor Materials LLC. • No additional response is required from RM. 2) Please commit to submitting Financial and Performance Warranties with the name Raptor Materials LLC. • No additional response is required from RM. 3) The Division received timely state agency comments from History Colorado and the Division of Water Resources, as well as a late comment letter from Colorado Parks and Wildlife. The letters from these agencies are included as an enclosure with this adequacy review letter. Please review the letters and provide comments accordingly. • No additional response is required from RM. Application Form 4) The application form must be updated to indicate that the new permittee is Raptor Materials LLC. • No additional response is required from RM. 5) On Page 1, Item #1.1 of the application form, the Applicant indicated the type of organization as a corporation. Please provide the corporation seal on Page 8 of the application form, if the corporation does not have a seal please indicate "no seal". • Please revise Page 8 of the form and add the text "no seat" 6.2 General Requirements of Exhibits 6) Rule 6.2.1(2)(b) requires maps be signed by a registered land surveyor, professional engineer, or other qualified person. Please submit signed copies of the Exhibit C and Exhibit F maps. • It is common practice for operators to provide signed maps. RM needs to comply with this request. Bradford Janes October 17, 2022 Page 3 6.4 Specific Exhibit Requirements - Regular 112 Operations The following items must be addressed by the Applicant in order to satisfy the Mineral Rules and Regulations of the Mined Land Reclamation Board: 6.4.1 Exhibit A - Legal Description 7) The Applicant indicated that a portion of the permit area is in Sections 3 and 4 of Township 4 North, Range 65 West. However, it appears (based on the Exhibit Map in Exhibit B) that the text should indicate Range 66 West instead of 65 West. Please address this apparent error, and revise the Exhibit A text as necessary. • No additional response is required from RM. 8) It appears that the coordinates for the Central Field SW Entrance are incorrect. Please check them and revise the Exhibit A text as necessary. (The coordinates listed for this entrance appear to be near the Varra Coulson Project.) • No additional response is required from RM. 6.4.3 Exhibit C - Pre -Mining and Mining Plan Maps of Affected Land 9) The irrigation ditches need to be clearly shown and labeled on the Existing Conditions Map (Exhibit C-1). • No additional response is required from RM. 10) Also, per Rule 6.4.3(e), the existing vegetation at the site should be shown. • No additional response is required from RM. 11) The scale on Exhibit C-1 appears to be incorrect. Please check and revise as necessary. • An additional response is required from RM. The scale bar appears to have incorrect numbers. Rather than 400 feet and 800 feet, it appears that the numbers should be 200 and 400. 12) The legend on Exhibit C-1 includes the 100 -year floodplain, but the floodplain lines are not on the map. These lines should be added to this map as well as the Extraction Plan Map, Exhibit C-2. • No additional response is required from RM. 13) For the sake of clarity, the Division recommends that the entire permit area be permitted to be affected, and this should be stated in Exhibit C and Exhibit D. (The Division recognizes that this statement is made in Exhibit L.) • No additional response is required from RM. Bradford Janes October 17, 2022 Page 4 14) During the pre -operations inspection on June 14, 2022, the idea of relocating the access point at the northwest corner of the site (to the east) was discussed. Please update Exhibit C-2 to reflect any change in that location. • No additional response is required from RM. 15) Please add the following to the Extraction Plan Map, Exhibit C-2: roads, parking and equipment storage areas, levees, soil piles, keyways, settling basins, and other structures pertinent to the mining operation that are not currently shown on the map. Comments on the map can indicate where these features are subject to change. • The Division reiterates that structures related to the mining operation need to be on Exhibit C-2. Regarding soil piles, RM states in the responses that, "There are no soil piles at this time," however, the purpose of the map is to illustrate the plan for soil piles in the future, and those should be shown on the map. • The Division requests that the term "keyway" be clarified by RM. Is this actually a de - watering trench? • The purpose of Annual Reports is described in Rule 1.15. These reports are not to be used to make changes to the mining and reclamation plans. Those changes must be made with technical revisions and amendments. 6.4.4 Exhibit D - Mining Plan 16) In this and other exhibits, an effort should be made to update agency names. For example, the Colorado Division of Wildlife is now Colorado Parks and Wildlife. The abbreviation CDH should be CDPHE. • No further response required by RM. 17) The mining plan (aka extraction plan) requires more detail. In particular, the plan should include a schedule that specifies the areas to be worked for given phases, with ranges of time periods. The phases described in Exhibit D should be coordinated with the Extraction Plan Map, Exhibit C-2. The operator can change the plan later, as needed, with technical revisions and/or amendments. Additional clarification on the sequence of the mining plan is necessary to calculate the required financial warranty. • RM needs to clarify an apparent contradiction between the response to item #17 and the approach to minimizing impacts on wildlife, as required by Rule 3.1.8. On page 15, the response states that "four separate extraction teams" could be used to hasten the extraction schedule. However, the ERO memorandum (August 26, 2022; page 2) describes an incremental approach that will protect mule deer habitat by only disturbing a relatively small area at one time. The text in the memo suggests that a maximum size for an active cell is 16 acres. This example illustrates the need to better define the mining and reclamation plans. Bradford Janes October 17, 2022 Page 5 18) The discussion on pages 6 and 7 regarding structures and easements should discuss which structures and easements will be relocated or removed from the site (if any). • As noted at the beginning of this letter, RM needs to revise actual exhibits (in this case Exhibit D) to address adequacy items and re -submit them. Also, please address the particular structures (above -ground and underground) and easements shown on Map G1. 19) On page 7, more detail is needed for the roads onsite. Please explain which roads will be built and which will be modified. Explain construction method and dimensions. • No further response required by RM. 20) On pages 12 —13, the discussion on stockpiles should include text indicating that soil management practices will protect the soil piles from erosion, prevent contamination of the soil from toxic or acid-forming material, and insure that the soil will remain usable for reclamation. • No further response required. The Extraction Plan does discuss how soil piles will be stabilized. It also discusses how fertilizer can compensate for the loss of organic matter. Finally, the applicant has stated that potentially toxic or acid forming materials would not be utilized in the reclamation activities. 21) On page 14 in the second to last paragraph, the sentence that begins "Specific variations in the location of ..." should be rewritten. The structure of this sentence does not follow standard rules of grammar, and (more importantly) the meaning is not clear. Please revise this statement accordingly. • RM needs to revise Exhibit D to address this item and re -submit it. 22) On page 14 in the last paragraph, the units are not specified (appears to be 125 feet), and this should be revised. Also, add a discussion on pipelines to this paragraph as appropriate. • RM needs to revise Exhibit D to address this item and re -submit it. 23) On page 16, regarding the discussion on topsoil and overburden stockpiles, more detail is needed regarding the storage volumes and locations of the piles, including distances from the piles to the areas to be reclaimed. It is recommended that they be shown on Map C-5. It should also be stated that the piles will be configured to prevent obstruction of flood waters, namely elongate the piles to make them parallel to the flow direction. • It appears that the extensive discussion on soils does not include any information regarding the quantities of soil in stockpiles or the location of soil piles. This Bradford Janes October 17, 2022 Page 6 information is required for a detailed reclamation cost estimate and needs to be added to the Extraction Plan, Exhibit D. 24) In the section Plant Site Development & Operations, text should be added regarding the details of structures that will be built, including the conveyor. Dimensions and other details should be provided to aid in the estimate of demolition costs for these structures. • More detail is needed regarding the conveyor. Please provide the size of the conveyor. Also, provide the dimensions of pads and other foundations that will be used for this structure and provide an estimate of the total volume of concrete that will be used. Related to this, Exhibit L will need to be updated to include the cost of dismantling the conveyor. • Please describe the measures to be taken to prevent material from overtopping the conveyor system and falling into the Big Thompson River. 25) In the section Plant Site Development & Operations, text should be added regarding the control of prairie dogs. Will they be relocated? • No further response required by RM. 26) The applicant should discuss the following (related to Rule 3.1.8): How will the operation minimize impacts on mule deer habitat during the winter season (December 1 through April 30). This should include (but not be limited to) a discussion on fencing. Fencing should be limited as practical, and wildlife -friendly fencing should be used. • No further response required by RM. 27) Include a discussion on how the operation will allow for deer and other animals to "escape" the mining operations. • No further response required by RM. 6.4.5 Exhibit E - Reclamation Plan 28) The Application form specifies that the post -mining land use of the site will be developed water resource. Additionally, the Applicant has provided a shadowing/mounding analysis for the installation of clay liners. However, the Reclamation Plan notes (page 5) that lining of the reservoirs is an option only. If the Applicant wishes to maintain lining of the reservoirs as an option only, then the Application must be revised to reflect that the reservoirs will be reclaimed to open groundwater ponds. If the Applicant chooses to reclaim the reservoirs to open groundwater ponds, then the following options are available to address the liability associated with exposed groundwater: a) Provide adequate bond to backfill the pit to two feet above the historic highest groundwater level. b) Obtain a court approved augmentation plan prior to exposing groundwater at the site. Bradford Janes October 17, 2022 Page 7 Alternatively, the Applicant may clarify that the post -mining land use of developed water resource will be achieved through clay lining the reservoirs. If the Applicant chooses to clay line the reservoirs, then the Applicant shall provide enough detail for the Division to calculate the cost to line the reservoirs. • RM must update Exhibit E to remove ambiguity in the plan in general, and in particular in comparison to the application form. 29) The reclamation plan requires more detail. In particular, the plan should include a schedule that specifies the areas to be reclaimed for given phases, with ranges of time periods. The phases described in Exhibit E should be coordinated with the Reclamation Plan Map, Exhibit F. • This item was not sufficiently addressed. Rule 6.4.5 requires details in the reclamation plan. In the event that an operator wishes to change the plan at a later date, a technical revision or amendment can be employed. 30) The discussion on pit slopes (pages 4 —5) should include a discussion on the method for grading these slopes, including push distances. Also, the discussion should include the method for verifying the final slopes and documenting this information. • No further response required from RM. 31) The reclamation plan needs to state that all compacted areas will be ripped prior to addition of topsoil and seed. • No further response required from RM. 32) The reclamation plan needs to include a clear plan for the storage and application of topsoil prior to seeding. The plan should include push distances to the areas and minimum depth. • It appears that the extensive discussion on soils does not include any information regarding the quantities of soil in stockpiles or the location of soil piles. This information is required for a detailed reclamation cost estimate and needs to be added to the Extraction Plan, Exhibit D. 33) On page 6, the discussion on seeding should include timing of seeding (and planting if applicable). At what time of year will seeding operations be conducted? • RM needs to revise Exhibit D to address this item and re -submit it. 34) The weed control paragraph (page 9) should reference the more detailed plan in Exhibit I/J. • RM needs to revise Exhibit D to address this item and re -submit it. Bradford Janes October 17, 2022 Page 8 35) The Backfill Notice must state the maximum quantity of inert fill that will be stockpiled on the site at any given time. This information is necessary to calculate the required financial warranty amount. Will buildings or other structures be constructed on backfill areas? If so, how will the material be placed and stabilized to prevent settling and voids? • No additional response is required of RM, but the Division would like to make two comments for the record. The purpose of the Backfill Notice is to address imported material, not material that originates within the permit area. Also, if imported material contains rubble or similar, RM should handle this material to avoid any instability of slopes. 36) The applicant should discuss the following related to the ponds: • The use of very flat slopes (8H:1V) and irregular shorelines in some locations, to allow for diverse habitat. • The use of constructed islands in the ponds for wildlife habitat. • No further response required from RM. 6.4.5 Exhibit F - Reclamation Plan Map 37) The permit boundary is not shown on this map and needs to be added (or the line weight needs to be larger to improve clarity). • No further response required from RM. 38) A legend should be added to the map clearly showing what the hatching and other features represent. A yellow box is shown at the southeast corner of the site; please indicate if this symbol represents a real feature or if it is an error. • The issue with the yellow box was not addressed. Please explain this feature on the map. Also, please remove the scale in the upper left portion of the map since it appears to be inaccurate. 39) It appears that the map requires more detail regarding the processing area. Do the topographical lines on Exhibit F accurately show the post -mining topography? If not, the map needs to be updated. • Please add a text box to the map explaining the topographical lines. If they illustrate pre -mining conditions, this should be stated. 40) Per Rule 6.4.6, post -mining land uses should be shown on the map. This is especially important for the material processing and wash pond areas. • RM needs to revise Exhibit F and re -submit it. As appropriate, the language included in the response letter from RM should be added to the map in a text box or in notes in the title block. Bradford Janes October 17, 2022 Page 9 41) Several structures and easements are shown on Exhibit C-1, and none are shown on Exhibit F. Please explain if all of these structures will be removed during the mining and reclamation operations. • Please confirm that Exhibit F is accurate. Are all above -ground and underground structures that will remain after mining is complete shown on the map? 42) The Division recommends adjusting the scale on this map. The current version includes considerable area that is beyond the permit boundary. • No further response required from RM. 6.4.7 Exhibit G - Water Information 43) On Page 1 of Exhibit G, the text states that the site will drain internally. Please add a statement that the site will be operated to prevent any significant runoff from disturbed areas from flowing offsite. Also state that the site will be operated to prevent any negative impacts to the hydrologic balance of the two rivers. • The Division agrees that the word "minimize" is appropriate, rather than "prevent." However, RM needs to revise Exhibit G and re -submit it. Exhibit G should include the statements requested in the original adequacy letter (using the word "minimize" as noted above). 44) Describe the physical dewatering system and provide a description of the operation of this system. • Please add to Exhibit G a summary of the system with references to other exhibits and other documents (e.g., the Water Quality Control Division application), as appropriate. 45) The Water Information exhibit should provide a detailed discussion of floodplain management at the site. This must include a discussion of the conveyor crossing of the Big Thompson River. It should also reference the Floodplain Permit report by Headwaters Corporation, as appropriate. • The text provide in the RM response that explains floodplain management at the site must be added to Exhibit G. • As noted above, Annual Reports should not to be used to make changes to the mining and reclamation plans, including the locations of structures. Those changes must be made with technical revisions and amendments. • Please explain the relevance of the Headwaters Corporation report included in the original submittal. Bradford Janes October 17, 2022 Page 10 46) To ensure that the Two Rivers project does not impact the hydrologic balance of the rivers, the application needs to include a water quality monitoring plan, specifically for the alluvium. The groundwater monitoring plan should be developed in accordance with Rule 3.1.7(7)(b) and should include a Quality Assurance Project Plan (QAPP) for the collection of groundwater samples. The plan should provide mitigation steps if there is an exceedance at a groundwater or surface water monitoring location. Potential impacts to quality and/or quantity the nearby domestic wells should also be addressed. A copy of the Division's Groundwater Monitoring and Protection Technical Bulletin has been included as an enclosure to this letter for your reference. • A water quality monitoring plan is required for this permit. Please develop that and include in the revised Exhibit G. 47) Change "NPDES" to "CDPS" to reflect the requirements of the Water Quality Control Commission. • No further response required from RM. Exh H - Wildlife 48) Indicate which recommendations on wildlife protection in "Threatened and Endangered Species Habitat Assessment, Two Rivers Parcels" (ERO, 2022) will be implemented at the site. This report was submitted with Exhibit H of your application. • No further response required from RM. Exhibits In 49) This exhibit should include a discussion on wetlands in the project area, including the wash pond and material processing areas. Please state that operations will be conducted to minimize impacts on wetlands or state that no operations will be conducted in wetland areas. • RM needs to revise Exhibits 14 and re -submit, with the discussion and statement regarding minimization of impacts. As appropriate, reference other exhibits and reports from other entities (e.g., the US Army Corps of Engineers). 50) In the Weed Management Plan, the paragraph that mentions the State of Colorado noxious weeds list should state that List A species will be eradicated and List B Species will be controlled. The plan should also describe the efforts that will be made to control List C species, including field bindweed, a focus in Weld County. The Division recognizes that mapping and vector identification can be useful tools for weed control, but these practices should not delay treatment of weeds. • RM did not address the adequacy item. RM needs to revise Exhibits 1/1, and re -submit, with the statements regarding listed species. Bradford Janes October 17, 2022 Page 11 6.4.12 Exhibit L - Reclamation Costs 51) This exhibit should be updated, as necessary, to match any revisions to Exhibits D and E, per the adequacy items for those sections. This includes details on structures. • In the context of this second adequacy letter, Exhibit L must be updated to reflect revisions to Exhibits D and E. 52) The cost estimate should include a task for ripping areas that will be topsoiled and vegetated. • RM did not address the adequacy item. RM needs to revise Exhibit L to include the ripping task. 53) The Applicant has noted under the Reclamation Plan (page 5) that water shares will be dedicated to the Division of Water Resources (DWR) to cover the liability associated with exposing groundwater. Please be aware that the Division no longer accepts the dedication of water shares to DWR as a bonding mechanism. The Applicant will need to post a financial warranty to allow for backfilling the areas of exposed groundwater or a financial warranty to cover the cost of installing clay liners in the reservoir. Please see additional comments under Item No. 29. • No further response required from RM. 6.4.13 Exhibit M - Other Permit and Licenses 54) Please commit to providing copies of all required and approved permits and licenses to the Division when available. This should include well permits and documents related to water rights, such as a Substitute Water Supply Plan. • No further response required from RM. 6.4.14 Exhibit N — Source of Legal Right to Enter 55) This document must show that Raptor Materials LLC (rather than Varra Companies, Inc.) has the legal right to enter lands under this permit. • No further response required from RM. 6.4.18 Exhibit R - Proof of Filing with County Clerk and Recorder 56) Please provide an affidavit or receipt indicating the date on which the revised application information required to address this adequacy letter was placed with the Weld County Clerk and Recorder for public review, pursuant to Subparagraph 1.6.2(1)(c). • No further response required from RM. Bradford Janes October 17, 2022 Page 12 6.4.19 Exhibit S - Permanent Man-made Structures 57) The Division requires Raptor Materials LLC to demonstrate that they attempted to obtain notarized structure agreements with all owners of the structures within 200 feet of the affected area of the proposed mine site, pursuant to Rule 6.4.19. This attempt must be made prior to the Division's consideration of a stability analysis. Please also indicate what agreements have been obtained. • RM needs to update Exhibit S with all relevant information including: o A list of all structure owners o A list of agreements obtained from these owners. 6.5 Geotechnical Stability Exhibit 58) The Division has reviewed the Slope Stability Analyses (prepared by AWES, LLC), and our comments are provided as an enclosure with this letter. Please review this memorandum and provide responses. • No further response required from RM. Please also respond to Division comments related to the dewatering evaluation (AWES LLC, 2020), enclosed with this letter. The Division is still reviewing one of the technical reports associated with this application: "Riverside Berm Failure Analysis and Flood Control Mitigation Plan" (Flow Technologies LLC, 2020). Division comments and questions related to this report will be sent under separate cover. Please be advised that the Two Rivers, Sand, Gravel, and Reservoir Project application may be deemed inadequate, and the application may be denied unless the above -mentioned adequacy review items are addressed to the satisfaction of the Division. If more time is needed to complete the reply, the Division can grant an extension to the decision date. This will be done upon receipt of a written waiver of the Applicant's right to a decision by November 4, 2022 and a request for additional time. This must be received no later than the decision date. If you have any questions, please contact me at rob.zu ber@state.co. us or (720) 601-2276. Sincerely, Robert D. Zuber, P.E. Environmental Protection Specialist Enclosure: Memorandum from Leigh Simmons regarding the dewatering evaluation Cc: Michael Cunningham, DRMS D COLORADO Division of Reclamation, Mining and Safety Department of Natural Resources Interoffice Memorandum October 14, 2022 From: Leigh Simmons To: Rob Zuber Subject: Two Rivers Sand, Gravel and Reservoir Project (Permit No. M-2022-013) Application I have reviewed the material submitted in response to my earlier adequacy review memo. My comments on the applicant's response are given below, together with the original comment for reference. Comments: 1. The proposed text of Section 6.4.7, Exhibit G, allows for the post -mining lining of the pits but does not commit to it. It is not appropriate for the Division to approve a contingent reclamation plan; the approved text should describe a single reclamation plan. If the decision is made at a later date to change the plan then an amendment application should be submitted at that time. Please revise the text of Exhibit G to describe the post -mining plan for the lining or otherwise of the excavated pits. The response is sufficient — the plan is to line the pits. 2. The text also refers to "OMLR" in places, which presumably stands for "Office of Mined Land Reclamation". This office does not exist in Colorado. Please replace any reference to "OMLR" in the text with "DRMS". The response is sufficient - the applicant has elected to continue to use "OMLR", with justification, despite the fact that the term is deprecated. 3. Water level data from piezometers P124-1 through P124-12 has been given in the text of Exhibit G but the locations of the piezometers are not shown on Exhibit G: Water Information Map (or Exhibit C-1: Existing Conditions Map). Please add the piezometer locations to Exhibit G: Water Information Map Piezometer locations have been shown on the updated version of Exhibit G: Water Information Map, however they are labelled using a different naming convention (see figure 1). Please label the piezometers on the map as they are referred to in the text of the AWES study. 1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 htt p: / / mining.state.co.us Jared S. Pol is, Governor Dan Gibbs, Executive Director Virginia Brannon, Director Page 2of6 10/14/2022 r 31.1 Rd t 1 s.4 - Figure l: Screenshot of portion of Exhibit G: Water Information Map 300% zoom 4. The key of Exhibit G: Water Information Map shows a symbol for wells, but no wells are identifiable on the map. It's not clear whether they were omitted or are not legible. Please identify all registered wells on Exhibit G: Water Information Map. Please also add a table to section 6.4.7 with details of these wells including their permit IDs, owners, date of construction and registered use. Water wells have been added to the updated version on Exhibit G: Water Information Map. No table has yet been provided. 5. Exhibit G: Water Information Map shows several symbols that are not included in the map key, and the text in many of the labels on the map is illegible (including what are presumably stream stage elevations). Please revise Exhibit G: Water Information Map to improve its legibility and to provide a complete key for map symbols (it may be helpful to remove the aerial imagery base -map). The revised map should be prepared and signed by a registered land surveyor, professional engineer, or other qualified person, as is required by Rule 6.2.1(2)(b). (With reference to the updated version of Exhibit G: Water Information Map): When the pdf of the map is viewed at 300% zoom most of the labels are legible (except where they are obscured by other map elements), however this level of zoom makes the map very difficult to use. Several symbols are used on the map but are not identified in the key or labelled on the map, these include: • Inverted red triangles (as shown in figure 1) • Bold red lines and squares (as shown in figure 2) • Yellow highlighting on contour lines (as shown in figure 2) Page 3of6 10/14/2022 • Dashed brown line (as shown in figure 2) • Yellow polygons (as shown in figure 3) • Blue marks (as shown in figure 3) • Fine dashed red lines (as shown in figure 3) • Light red dots (as shown in figure 3) • Black triangles (as shown in figure 3) The map has not been signed, stamped, or otherwise certified by a registered land surveyor, professional engineer, or other qualified person. Figure 2: Screenshot of portion of Exhibit G: Water Information Map (adj 300% zoom 111Wr 1 l Bu.. Figure 3: Screenshot of portion of Exhibit G: Water Information Map . (di 300% zoom Page 4 of 6 10/14/2022 In 6.4.7(1) the statement is made that "Operations will not adversely affect surface and groundwater systems". In support of the statement, the text refers to a July 27, 2020 study by American Water Engineering Services, LLC of Fort Collins, CO (AWES 2020). American Water Engineering Services, LLC was formed in 2011 and is currently in good standing with the Colorado Secretary of State's office. The AWES 2020 report presents a hydrogeologic evaluation based on a numerical groundwater flow model built with Visual ModFlow Pro, an industry standard groundwater flow modeling code. Background information is given in the report, followed by assumptions, model parameters, results and conclusions. Figures and plates are appended to the report. By its nature a numerical groundwater flow model is a simplification of the real system and is built using a series of assumptions and compromises on the part of the modeler, with the goal of answering pertinent questions about the system. The questions that the AWES 2020 model seeks to answer are not specifically defined, but are generally stated as "to estimate the effects of dewatering operations on the surrounding groundwater hydrology". In my review of the AWES 2020 model I have tried to avoid "nit-picking" but to look first at the overall validity of the conclusions that can be drawn from it, and then to evaluate whether those conclusions support the statement that "Operations will not adversely affect surface and groundwater systems". Questions 6 through ... below are asked to help the Division better understand the model. The AWES report was updated on August 31, 2022. 6. Key assumptions of the model are that the aquifer is unconfined, homogenous and anisotropic, with a horizontal hydraulic conductivity (Kh) of 125 ft/day and a vertical hydraulic conductivity (Kv) of 12.5 ft/day. The K values are at the lower end of the expected range of 2000-100 ft/day (Robson, 1989). Please justify the assumption of anisotropy and the chosen K values for the sand and gravel aquifer. 7. The piezometers referred to in (3) are described as monitoring wells in AWES 2020. Please describe how these wells were used for pre -mining aquifer characterization (besides the collection of water level data). The response to 6 and 7 is sufficient - the author has assumed aquifer properties based on his prior experience of similar geologic settings. Although the assumed hydraulic conductivity values seem reasonable with respect to the literature, it is a notable weakness of the AWES study that the opportunity wasn't taken to use the constructed monitoring wells to conduct any field tests of aquifer properties. There are many published equations linking hydraulic conductivity and grain size of the form "K is proportional to d10" since it was first proposed in the 1890s, but they are of doubtful validity, are generally only employed when other methods of estimating hydraulic conductivity are not available, and the value of the proportionality constant is usually empirically derived — I'm not aware of any justification for assuming a proportionality constant of 1, and none has been presented, (Hazen, 1892; Eggleston, 2001; Carrier, 2003). 8. No information is presented about the vertical extent of the model. How many vertical layers are used in the model? What are the layer thicknesses? The response is sufficient - there are two vertical layers in the model, with the upper layer representing unconsolidated alluvial deposits and the lower layer representing bedrock. Page 5of6 10/14/2022 9. No information is presented about recharge from precipitation. Is recharge from precipitation accounted for in the model, or is its impact assumed to be negligible? The response is sufficient - a 1.5 inch recharge rate was assumed. 10. The Mine Area Map presented as Figure 2 shows a different pit configuration from that presented elsewhere in the permit application packet (PAP) — it shows three pits, whereas Exhibit G: Water Information Map, for example, shows just two. The Model Boundary Conditions presented as Plate 1 reflect the configuration shown in Figure 2. Please discuss the validity of the model boundary conditions in the light of the final pit configuration (which is assumed to be that shown on maps in the PAP). The response is sufficient — the model boundary conditions were updated to correspond more closely to the two pit configuration shown elsewhere in the mine plan. 11. According to the literature, water table gradients in the alluvial aquifers of the region are typically in the range 0.002 to 0.007 (Arnold, Langer & Paschke, 2003). The water table contour map presented as Plate 3 shows a generally easterly gradient of 0.002 across the center of the proposed permit area. A single data point (MW -1, which is presumably the same as P124-1) exists north of the Big Thompson River, with a significantly higher water level. This distorts the water level contours in the north of the study area, suggesting a far steeper gradient (0.01) and a south-easterly flow direction. Please discuss the characterization of the pre -mining water table. How reliable is the data from MW -1? How do you account for the steeper gradient? Are there any other data points in the north of the study area to improve the characterization? The response is sufficient — the author has used the available data to characterize the site as thoroughly as possible. 12. The model was calibrated using model -assigned observation wells outside of the proposed excavations, (presumably the points shown with green and white symbols on Plates 6 and 7). The first two sentences of the final paragraph on Page 3 of the AWES 2020 report suggest that water levels were measured at these locations, but I think that these are simulated wells. Plates 5 and 5A show the calibration results. They appear to show identical data. Water level contours showing initial conditions in the calibrated model are presented as Plate 4. The contours suggest a gradient of 0.06 to the SSE in the north of the study area. Please clarify the initial calibration process. Please discuss the validity of the model in the north of the study area. The response is sufficient - the author thoroughly described the model calibration process 13. The results of the dewatering simulation are presented as Plate 6. This is presumably a steady state simulation. It simulates dewatering of the central and north-west pits only. Please simulate the dewatering of the full extent of the mined area. Please estimate the time to achieve steady state conditions. Page 6 of 6 10/14/2022 The steady state drawdown scenario is presented on Plate 7. In the Conclusions section of the report the author states: "The predicted drawdown associated with the mine dewatering represents the worst case scenario and a substantial amount of time will be required before maximum drawdowns will occur". Please estimate the amount of time, based on model results, for maximum drawdowns to occur. 14. Table 1 presents the predicted water levels at the 4 simulated wells before mining and following the lining of the mined pits. Please add a column to Table 1 showing the predicted water levels under the pit de -watering scenario. The table should show the fullest extent of the potential drawdown caused by the mine operation. The response is sufficient — Table 1 shows maximum predicted drawdowns at the 4 simulated wells, as well as the predicted post -pit -lining water elevation. 15. In the conclusions section on Page 4 of the report, the statement is made that "The results of analytical and numerical solutions indicate..." however no analytical solutions are presented. Please update the report to present any relevant analytical solutions that support the conclusion. The response is sufficient — analytical solutions are used earlier in the report. I have not addressed the requirements for water monitoring in this memo, but 1 note that you discussed it in item 46 of your preliminary adequacy review letter. Water monitoring data will be important to validate model predictions in the future. No water monitoring program has yet been proposed. References: Arnold, L.R., Langer, W.H. and Paschke S.S., 2003, Analytical and Numerical Simulation of the Steady - State Hydrologic Effects of Mining Aggregate in Hypothetical Sand -and -Gravel and Fractured Crystalline - Rock Aquifers, U.S. Geological Survey Water Resources Investigations Report 02-4267 https://pubs.usgs.gov/wri/2002/4267/report.pdf Carrier, W. D., 2003. Goodbye, Hazen; Hello, Koceny-Carman. Journal of Geotechnical and Geoenvironmental engingeering, 129(11), pp. 1054-1056. https://ascelibrary.org/doi/epdf/10.1061/%28ASCE%291090-0241%282003%x29129%3A11%2810541029 Eggleston, J. & Rojstaczer, S., 2001. The Value of Grain -size Hydraulic Conductivity Estimates: Comparison with High Resolution In -situ Field Hydraulic Conductivity. Geophysical Research Letters, November, 28(22), pp. 4255-4258. https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2000GL012772 Hazen, A., 1892, Experiments upon the purification of sewage and water at the Lawrence Experiment Station, Massachusetts State Board of Health 23rd Annual Report. https://www.gutenberg.org/files/69025/69025-h/69025-h.htm Robson, S.G., 1989, Alluvial and Bedrock Aquifers of the Denver Basin Eastern Colorado's Dual Groundwater Resource, U.S. Geological Survey Water Supply Paper 2302 https://pubs.usgs.gov/wsp/2302/report.pdf 8120 Gage Street • Frederick, Co 80516 Bus: (303) 666-6657 • Fax: (303) 666-6743 Wednesday 04 January 2023 To: Robert D. Zuber, Environmental Protection Specialist Colorado Division of Reclamation Mining and Safety Office of Mined Land Reclamation (OMLR) 1313 Sherman Street, Room 215 Denver, Colorado 80203 From: Garrett C. Varra, General Manager Raptor Materials, LLC 8120 Gage Street Frederick, Colorado 80516. Subject :Two Rivers Sand, Gravel and Reservoir Project, File No. M-2022-013, 112c Permit Application Adequacy Review #2 — REPSPONSE Dear Rob, The Division of Reclamation, Mining and Safety (Division/DRMS), Office of Mined Land Reclamation (OMLR); reviewed the contents of the original ilk permit application for the Two Rivers Sand, Gravel e and Reservoir Project (TRP), File No. M-2022-013 and submitted comments via Adequacy Letters of 24 June and 5 August 2023 which were responded to by Raptor Materials on 6 September 2022. Raptor Materials received a Second Adequacy Review dated 17 October 2022 The current decision date is 15 February 2023. Please find attached the following documents as our response: • Raptor Materials adequacy response of 04 January 2023 to Colorado Office of Mined Land Reclamation Second Adequacy ResponseCover Letter • Second Adequacy Response to DRMS M S • • Updated 112 Form Updated Exhibit D — Extraction Plan Updated Exhibit E — Reclamation Plan Updated Exhibit G — Water Information Updated Exhibit in Soils Information • Updated Exhibit 1.— ReclamationCosts • Updated Exhibit M — Other Permits and Licenses • Updated — Owners of Record of Affected Land and Owners of Substance to be Mined Exhibit • Updated Exhibit S — Permanent Man-made Structures Addenda • Updated Exhibit Cl Maps Existing Conditions • Updated Exhibit C2 Map — Extraction Plan • Updated Exhibit F Map — Reclamation Plan • Updated Exhibit G Map e Water Information • Updated Exhibit In Map --Soils and Vegetation • Updated Exhibit L Map s Financial Warranty) Raptor has also reviewed twelve separate objections and comments submitted timely to the DRMS by ten private individuals and one representative of a company with structures in the 200 -foot limit of the Affected Area. The company objection submitted by Paul Montville of PD Energy has subsequently been withdrawn p Y (October 28, 2022 letter to DRMS). From the remaining eleven comments and objections, Raptor believes the following jurisdictional categories are noted. category Comments Adequacy Zoning/ Land Use 2 Hydrologic Balance 1 Wildlife/ Sensitive Environment/ Flood plain issues 2 Completeness/ Accuracy of the provided materials by 1 the applicant Notice Yes Yes Yes Yes Yes Application/Note Jurisdictional in that it is required. Zoning is appropriate. Land use is supported under statute. Thoroughly addressed in Exhibit G and supported by AWES analysis and reports. Thoroughly addressed. in Exhibit H and supported by ERO analysis and reports. Application deemed complete by DRMS and adequacy of the application is largely complete. Proof of notification has been submitted and no issues have been identified. Several other categories of objection have been noted, which Raptor believes to be non -jurisdictional to the DRMS. There include visual impacts, economic impacts/ property values, noise, offsite traffic/safety, fugitive dust/air quality, impacts to recreational activities, and life of mine. Additionally, our response to "comments on the Berm Failure Analysis" dated 17 November 2022 are pending, Additional time is required to analyze and address those comments. That response will be sent directly to you at a date sometime in the near future, Regards, Garrett Varra General Manager STATE OF COLORADO DIVISION OF RECLAMATION, MINING AND SAFETY Department of Natural Resources 1313 Sherman St., Room 215 Denver, Colorado 80203 Phone: (303) 866-3567 FAX: (303) 832-8106 APPLICABILITY: CONSTRUCTION MATERIAL REGULAR (112) OPERATION RECLAMATION PERMIT APPLICATION PACKAGE COLORADO DIVISION OF RECLAMATION MINING SAFETY This application package is for a construction materials operation which affects 10 acres or more. If you plan to conduct a construction materials extraction operation which meets these criteria, please follow the instructions provided in this package, in the Rules and Regulations, and in the Colorado Land Reclamation Act for the Extraction of Construction Materials, as required. RECOMMENDATIONS PRIOR TO FILING: The Construction Material Rules and Regulations (the Colorado Land Reclamation Act for the Extraction of Construction Materials, Section 34-32.5-101, et seq., C.R.S., and 2 CCR 407-1) and the Colorado Mined Land Reclamation Board (the "Board") regulate the permitting, operational and reclamation requirements for all construction material extraction operations in Colorado. It is your obligation to comply with the Act and Regulations. You are encouraged to obtain and review a copy of the Rules, available for $8.00 from the Division of Reclamation, Mining, and Safety (the "Office"). In order to submit your application properly, it is recommended that you review the Act and: Rule 1.1 Rule 1.4.1 Rule 1.4.5 Rule 1.6 Rule 3.1 Rule 3.3.1 Rule 4 Rule 6 Rule 6.2 Rule 6.4 Rule 6.5 Definitions; Application Review and Consideration Process; Specific Requirements for Regular 112 Operations; Public Notice Procedures; Reclamation Performance Standards; Operating without a Permit - Penalty; Performance Warranties and Financial Warranties; Permit Application Exhibit Requirements; General Requirements of Exhibits; Specific Permit Application Exhibit Requirements; and Geotechnical Stability Exhibit. It is recommended that you contact the agencies listed in the application section titled "Com submitting the application to the Office . 2liance With Other Laws" prior to Office of Mined Land Reclamation Office of Denver • Grand Junction • Durango Active and Inactive Mines FILING REQUIREMENTS: In order to apply for a Reclamation Permit for a Regular 112 Operation, please provide: o One (1) signed and notarized completed ORIGINAL and one (1) copy of the completed original Regular 112 Operation Application Form. ORIGINAL SIGNATURES MUST BE DONE IN BLUE INK. o Two (2) copies of Exhibits A -S (required sections described in Rule 6). o Two (2) copies of Addendum 1 -Notice requirements (described in Rule 1.6.2(1)(b)). A sample of this notice is attached for your use. o The Geotechnical Stability Exhibit when required by the Division. o The application fee. The ninety (90) day period for review of the application and exhibits will NOT begin until all required information and fee are submitted. The Office will then review the submitted information for adequacy. NOTICE REQUIREMENTS: 1. You MUST send a notice, on a form approved by the Board, to the local board of county commissioners. A copy of this "Notice of Filing Application" form is attached for your use. 2. If the mining operation is within the boundaries of a conservation district, send a notice to the board of supervisors of the conservation district, PRIOR to filing the application. A copy of this "Notice of Filing Application" form is attached for your use. 3. You MUST include proof of notice #1 and #2 above with the application at the time the application is submitted to the Office for filing (Rule 1.6.2(1)(g)). 4. PRIOR to filing the application, place for public review a copy of the application, less confidential items, with the clerk or recorder of the county or counties in which the affected land is located. 5. You MUST include an affidavit or receipt demonstrating that the application was filed with the county clerk or recorder at the time the application is submitted to the Office for filing. 6. Any changes or additions made to an application submittal MUST be filed with the county clerk or recorder. You MUST also provide the Office with an affidavit or receipt demonstrating that the change was filed with the county clerk or recorder no later than the close of business on the day the change was filed with the Office (Rule 1.8.1(2)). 7. Within ten (10) days after your application is considered filed, you must publish four times in a newspaper of general circulation, in the locality of the proposed mining operation, the notice described in Rule 1.6.2(1)(d). 8. In addition, after the first publication you must mail or personally serve a copy of the notice described in Rule 1.6.2(1)(d) to all owners of record of surface rights to the affected land and all owners of record of lands that are within 200 feet of the boundary of the affected land (Rule 1.6.2(1)(e)). A copy of a form which includes all required information for the notice is attached for your use. 9. Prior to the Office making a decision (consideration ofthe application), you MUST submit a copy of the proof of publication from the newspaper and proof of all required notices. Proof of the notices may be by submitting copies of return receipts of a certified mailing or by proof of personal service (Rules 1.4.1(4), 1.4.2(4)(c), 1.6.2(1)(a)(ii), and 1.6.2(1)(g)). The copy of the application and any changes or additons placed at the office of the county clerk or recorder shall NOT be recorded, but shall be retained there for at least sixty (60) days after a decision on the application by the Office and be available for inspection during this period. At the end of this period, the application may be reclaimed by the applicant or destroyed (Rule 1.6.2(2)). APPLICATION REVIEW PROCEDURES: The Office shall approve or deny the application within ninety (90) days of filing unless the date for consideration by the Office is extended pursuant to Rule 1.8. The time for consideration shall not be extended beyond ninety (90) days after the last such change submitted. For complex applications, the review period may be extended an additional sixty (60) days. Please see Rule 1.1(10) for the definition of what constitutes a complex application. APPLICATION APPROVAL/DENIAL: If the requirements of the Act and Mineral Rules have been satisfied, the Office will approve the application. The Act also provides for automatic approval if no action is taken by the Office by the end of the review period. If the Act and Regulation requirements have not been satisfied, the Office will deny the application. If the Office denies the application, you may appeal to the Board for a final determination by submitting a written request for administrative appeal to the Board within 60 days of the decision date (Rule 1.4.7). PERFORMANCE AND FINANCIAL WARRANTIES: A performance warranty, and a financial warranty dollar amount determined during the application review process, must be submitted and approved by the Office PRIOR to permit issuance. A financial warranty should NOT be submitted until a decision on the application has been made. If the applicant is a unit of state or county government, then ONLY a performance warranty is required. Several different types of financial warranties are allowed by the law. Please review Rule 4.0 to determine which type of financial warranty you desire to use. You may obtain the appropriate warranty forms from the Office during the application review period. Please note that an application approval DOES NOT convey a right to begin operations. You MUST submit, and have approval of your performance and financial warranties, and receive your copy of the signed permit document PRIOR to beginning on -site mining activity. AUTOMATIC PERMIT APPROVAL: An automatic approval will occur where the Office fails to notify the applicant/operator that the application has been denied. This decision must be made ninety (90) calendar days from the date the application was determined to have been filed. However, the performance and financial warranties must be submitted and approved by the Office before the permit will be issued even if you receive an automatic approval. NO MINING OPERATIONS SHALL BEGIN UNTIL A PERMIT IS ISSUED (Section 34-32.5-109(1), C.R.S.). -iv - COMPLIANCE WITH OTHER LAWS: Compliance with the Act and Rules and Regulations of the Mined Land Reclamation Board DOES NOT relieve you of your responsibility to comply with all other applicable state and federal laws. We recommend that you contact the following agencies to determine whether you need to comply with their legal requirements: o The Colorado State Historical Preservation Office regarding properties of historical significance including the need for an archeological survey, procedures for requesting a file search, and inventory forms to identify structures. o Colorado Division of Water Resources with regard to water rights; Colorado Department of Health, Water Quality Control Division, with regard to the discharge of pollutants into the State waters; o Colorado Department of Health, Air Pollution Control Division, with regard to the need for a fugitive dust permit; o U.S. Bureau of Land Management or the U.S. Forest Service if the proposed operation will occur on federal lands; o U. S. Army Corps of Engineers regarding a dredge and fill (404) permit; and The County Planning Department for the county or counties in which your proposed operation is located. Section 34-32.5-109(3), C.R.S, requires a mining operator to be responsible for assuring that the mining operation and the post -mining land use comply with local land use regulations and any master plan for extraction adopted pursuant to Section 34-1-304, C.R.S. COMPLETION OF MINING: Upon completion of any phase of reclamation, you should consult Rule 3.1 for reclamation standards and 4.16 for details on how to request a reclamation responsibility release from the Board. STATE OF COLORADO DIVISION OF RECLAMATION, MINING AND SAFETY Department of Natural Resources 1313 Sherman St., Room 215 Denver, Colorado 80203 Phone: (303) 866-3567 FAX: (303) 832-8106 CONSTRUCTION MATERIALS REGULAR (112) OPERATION RECLAMATION PERMIT APPLICATION FORM CHECK ONE: ✓ There is a File Number Already Assigned to this Operation COLORADO DIVISION OF RECLAMATION MINING SAFETY Permit # MZ,g22 - 013 (Please reference the file number currently assigned to this operation) New Application (Rule 1.4.5) Conversion Application (Rule 1.11) Amendment Application (Rule 1.10) Permit # M - (provide for Amendments and Conversions of existing permits) The application for a Construction Materials Regular 112 Operation Reclamation Permit contains three major parts: (1) the application form; (2) Exhibits A -S, Addendum 1, any sections of Exhibit 6.5 (Geotechnical Stability Exhibit; and (3) the application fee. When you submit your application, be sure to include one (1) complete signed and notarized ORIGINAL and one (1) copy of the completed application form, two (2) copies of Exhibits A -S, Addendum 1, appropriate sections of 6.5 (Geotechnical Stability Exhibit, and a check for the application fee described under Section (4) below. Exhibits should NOT be bound or in a 3 -ring binder; maps should be folded to 8 1/2" X 11" or 8 1/2" X 14" size. To expedite processing, please provide the information in the format and order described in this form. GENERAL OPERATION INFORMATION Type or print clearly, in the space provided, ALL information requested below. 1. Applicant/operator or company name (name to be used on permit): Raptor Materials, LLC. 1.1 Type of organization (corporation, partnership, etc.): Limited Liability Company 2. Operation name (pit, mine or site name): Two Rivers Sand, Gravel & Reservoir Project 3 Permitted acreage (new or existing site) : 3.1 Change in acreage (+) 3.2 Total acreage in Permit area 4. Fees: 4.1 4.2 4.4 4.5 New Application New Quarry Application Amendment Fee Conversion to 112 operation (set by statute) 5 Primary commoditie(s) to be mined: sand 5.1 Incidental commoditie(s) to be mined: 1. 3. / lbs/Tons/yr 4. gravel earth products lbs/Tons/yr 2. 409.234 permitted acres acres acres $2,696.00 $3,342.00 $2,229.00 $2,696.00 application fee quarry application amendment fee conversion fee lbs/Tons/yr / lbs/Tons/yr 5. / lbs/Tons/yr 5.2 Anticipated end use of primary commoditie(s) to be mined: commercial urban & rurual infrastructure needs N/A 5.3 Anticipated end use of incidental commoditie(s) to be mined: 6. Name of owner of subsurface rights of affected land: Raptor Materials, LLC. If 2 or more owners, "refer to Exhibit O". 7 Name of owner of surface of affected land: Raptor Materials, LLC. 8. Type �e of mining operation: eration: Surface 1' Underground 9 Location Information: The center of the area where the majority of mining will occur: COUNTY: Weld PRINCIPAL MERIDIAN (check one): SECTION (write number): TOWNSHIP (write number and check direction) : RANGE (write number and check direction) : QUARTER SECTION (check one) : QUARTER/QUARTER SECTION (check one) : 6th (Colorado) 10th (New Mexico) s3 T4 R 66 i North East _ South West NE I " NW In SE r SW NE NW SE ' SW Ute GENERAL DESCRIPTION: (the number of miles and direction from the nearest town and the approximate elevation): 10. Primary Mine Entrance Location (report in either Latitude/Longitude OR UTM): Latitude/Longitude: Example: (N) 39° 44' 12.98" (W) 104° 59' 3.87" Latitude (N): deg min sec (2 decimal places) Longitude (W): deg nun sec (2 decimal places) OR Example: (N) 39.73691° (W) -104.98449° Latitude 40 .348174 (5 decimal places) P ) Longitude(W) -104 .776631 (5 decimal places) OR Universal Tranverse Mercator (UTM) Example: 201336.3 E NAD27 Zone 13 4398351.2 N s eci NAD27, NAD83 or WGS 84) N ad 83 Zone 13 UTM Datum (specify Easting Northing 11. Corresvondence reformation: APPLICANT/OPERATOR (name, address, and phone of name to be used on permit) Contact's Name: Kevin Jeakins Tide: Vice -President Company Name: Raptor Materials, LLC. Street/P.O. Box: 8120 Gage Street P.J. Box: City: Frederick State: Colorado Zip Code: 8°516 Telephone Number: (303 ) _ 666-6657 Fax Number: (303 ) .. 666-6743 PERMITTING CONTACT (if different from applicant/operator above) Garrett G. Varra Title: General Manager Contact's Name: Company Name: Street/P.O. Box: City: State: Telephone Number: Fax Number: INSPECTION CONTACT Contacts Name: Company Name: Street/P.O. Box: City: State: Telephone Number: Fax Number: Raptor Materials, , LLC. 8120 Gage Street Frederick P.O. Box: Colorado (303 )- 666-6657 (303 ) - 666-6743 Zip Code: 80°16 Garrett C. Varra Title: General Manager Raptor Materials, LL. 8120 Gage Street P.O. Box: Frederick Colorado (303 ) _ 666-6657 (303 ) s 666-6743 CC: STATE OR FEDERAL LANDOWNER if any) Agency: Street: City: State: Zip Code: 80516 Zip Code: Telephone Number: ( a CC: STATE OR FEDERAL LANDOWNER Of any) Agency: Street: City: State: Zip Code: Telephone Number: C ) r 4 12. Prima future (Post -mining) land use (check one): rcpland(CR) fl Pastureland(PL) El Rangeland(RL) r] Forestry(FR) El Residential(RS) flRection(R) Trif Developed Water Resources(WR) 13. Primary present land use (check one Cropland(R) Rangeland(RL) Residential(RS) Pastureland(PL) Forestry(FR) RecreationCR ) Developed Water Resources(WR) r General Agrictiiture(GA) Wildlife Habitat(WL) IndustrialJCommerci al(IC) n Solid Waste Disposal(WD) General Agricuiture(A) Wildlife Habitat(WL) Industrial/Commercial(1C) 14. Method of Mining: Briefly explain mining method (e.g, truck/shovel): Surface extraction, processing, and transport of aggregate resources until bedrock establishment of final basins is mplete. 15_ On Site Processing : 11717 Crushing/Screening 13.1 Briefly explain mining method (e.g. truck/shovel): In place extraction of unconselidate+d soil and aggregate by excavators, dozers, scrapers, or backhoes followed by transportation by conveyor or haul truck to a processing locations where material ps crushed, screened, end prepared and stockpiled for commercial sale and removal from property. All extracted materials may be utilized for either commercial purposes or on -site reclamation and development. List any designated chemicals or acid -producing materials to be used or stored within permit area: None 16. Description of Amendment or Conversion: If you are amending or converting an existing operation, provide a brief narrative describing the proposed change(s). N/A - Mans and Exhibits: Two (2) complete, unbound application packages must be submitted. One complete application package consists of a signed application form and the set of maps and exhibits referenced below as Exhibits A - S, Addendum 1, and the Cieotechnical Stability Exhibit. Each exhibit within the application must be presented as a separate section. Begin each exhibit on a new page. Pages should be numbered consecutively for ease of reference. If separate documents are used as appendices, please reference these by name in the exhibit. With each of the two (2) signed application forms, you must submit a corresponding set of the maps and exhibits as described in the following references to Rule 6.4, 6.5, and 1.6.2(1)(b): EXHIBIT A EXHIBIT B EXHIBIT C EXHIBIT D EXHIBIT E EXHIBIT F EXHIBIT G EXHIBIT H EXHIBIT I EXHIBIT J EXHIBIT K EXHIBIT L EXHIBIT M EXHIBIT N EXHIBIT 0 EXHIBIT P EXHIBIT EXHIBIT R EXHIBIT S Rule 1.6.2(1)(b) Rule 6.5 Legal Description Index Map. Pre -Mining and Mining Plan Map(s) of Affected Lands Mining Plan Reclamation Plan Reclamation Plan Map Water Information Wildlife Information Soils Information Vegetation Information Climate Information Reclamation Costs Other Permits and Licenses Source of Legal Right -To -Enter Owners of Record of Affected Land (Surface Area) and Owners of Substance to be Mined Municipalities Within Two Miles Proof of Mailing of Notices to County Commissioners and Conservation District Proof of Filing with County Clerk or Recorder Permanent Man -Made Structures ADDENDUM I - Notice Requirements (sample enclosed) +eotechnical Stability Exhibit (any required sections) The instructions for preparing Exhibits A -S, Addendum I, and Geotechnical Stability Exhibit are specified under Rule 6.4 and 6.5 and Rule 1.6.2(1)(b) ofthe Rules and Regulations. If you have any questions on preparing the Exhibits or content ofthe information required, or would like to schedule a pre -application meeting you may contact the Office at 303-866-3567. Responsibilities as a Permittee: Upon application approval and permit issuance, this application becomes a legally binding document. Therefore, there are a number of important requirements which you, as a permittee, should fully understand. These requirements are listed below. Please read and initial each requirement, in the space provided, to acknowledge that you understand your obligations. If you do not understand these obligations then please contact this Office for a full explanation. I,. Your obligation to reclaim the site is not limited to the amount of the financial warranty. You assume legal liability for all reasonable expenses which the Board or the Office may incur to reclaim the affected lands associated with your mining operation in the event your permit is revoked and financial warranty is forfeited; VS. sts ‘4‘ Y.r 2. The Board may suspend or revoke this permit, or assess a civil penalty, upon a finding that the permittee violated the terms or conditions of this permit, the Act, the Mineral Rules and Regulations, or that information contained in the application or your permit misrepresent important material facts; 3. If your mining and reclamation operations affect areas beyond the boundaries of an approved permit boundary, substantial civil penalties, to you as permittee can result; 4. Any modification to the approved mining and reclamation plan from those described in your approved application requires you to submit a permit modification and obtain approval from the Board or Office; 5. It is your responsibility to notify the office of any changes in your address or phone number; 6. Upon permit issuance and prior to beginning on -site mining activity, you must post a sign at the entrance of the mine site, which shall be clearly visible from the access road, with the following information (Rule 3.1.12): a. the name of the operator; b. a statement that a reclamation permit for the operation has been issued by the Colorado Mined Land Reclamation Board; and, c. the permit number. 7. The boundaries of the permit boundary area must be marked by monuments or other markers that are clearly visible and adequate to delineate such boundaries prior to site disturbance. 8. It is a provision of this permit that the operations will be conducted in accordance with the terms and conditions listed in your application, as well as withthe provisions of the Act and the Construction Material Rules and Regulations in effect at the time the permit is issued. 9. Annually, on the anniversary date of permit issuance, you must submit an annual fee as specified by Statute, and an annual report which includes a map describing the acreage affected and the acreage reclaimed to date (if there are changes from the previous year), any monitoring required by the Reclamation Plan to be submitted annually on the anniversary date of the permit approval. Annual fees are for the previous year a permit is held. For example, a permit with the anniversary date ofJuly 1, 1995, the annual fee is for the period of July 1, 1994 through June 30, 1995. Failure to submit your annual fee and report by the permit anniversary date may result in a civil. penalty, revocation of your permit, and forfeiture of your financial warranty. It is your responsibility, as the pe . ettee, to continue to pay your annual fee to the office until the Board releases you from your total reclamation respo►ns b i l i ty . 10. For joint venture/partnership operators: the signing representative is authorized to sign this document and a power of attorney (provided by the partner(s)) authorizing the signature of the representative is attached to this application. 7 NOTE TO COMMENTORS/OBJECTORS: S/O ECToRS: It is likely there will be additions, changes, and deletions to this document prior to final decision by the Office. Therefore, if you have any comments or concerns you must contact the applicant or the Office prior to the decision date so that you will know what changes may have been made to the application document. The Office is not allowed to consider comments, unless they are written, and received prior to the end of the public comment period. You should contact the applicant for the final date of the public comment period. Ifyou have questions about the Mined Land Reclamation Board and Offices review and decision or appeals process., you may contact the Office at (303) 866-3567. Certification: As an authorized representative of the applicant, I hereby certify that the operation described has met the minimum requirements of the following terms and conditions: 1. To the best of my knowledge, all significant, valuable and permanent nnanemade structure(s) in existence at the time this application is filed, and located within 200 feet ofthe proposed affected area have been identified in this application (Section 34-32.5-115(4)(e), C.R.S.). 2. No mining operation will be located on lands where such operations are prohibited by law (Section 34-32.5-115(4)(i C.R.S., 3. As the applicantioperator, I do not have any extraction/exploration operations in the State ofColorado currently in violation of the provisions of the Colorado Land Reclamation Act for the Extraction of Construction Materials (Section 34-32.5-120, C.R.S.) as determined through a Board finding. 4. I understand that statements in the application are being made under penalty of perjury and that false statements made herein are punishable as a Class 1 misdemeanor pursuant to Section 18-8.503, C.R.S. This farm has been approved by the Mined Land Reclamation Board pursuant to section 34-32.5-I '2, R. '., of the Colorado Land Reclamation Actfor the Extraction of Construction Materials. Any alteration or modification °fats form shall result in voiding any permit issued an the altered or modified form and subject the operator to cease and desist orders and civil penalties, for operating without a permit pursuant to section 34-32.5-123, &. Signed and dated this 1 gstriA day of ital S , ev\A Applicant/Operator or Company Name Signed: Title: Kevin Jeakins, Vice -President State of County of tAi )ss If Corporation Attest (Seal) NO SEAL/NO CORPORATE SECRETARY - This is a Limited Liability Company Signed: The foregoing instrument was acknowledged before me this 4 % day of 20!2, by .e Viet dealt' ' A s as vP JESSICA HOOVER NOTARY PUBUC STATE OF COLORADO NOTARY ID 20044035571 MY COMMISSION EXPIRES OCTOBER 4, 2024 abs Corporate Secretary or Equivalent Town/City/County Clerk lake of €&04*or Make rs l,L My Commission expires: I DI 412 SIGNATURES MUST BE IN BLUE INK You must post sufficient Notices at the location of the proposed mine site to clearly identify the site as the location of a Page I1 6.4.4 EXHIBIT D — Extraction Plan The mining plan shall supply the following information, correlated with the affected lands, map(s) and timetables: (a)description of the method(s) of mining to be employed in each stage of the operation as related to any surface disturbance on affected lands; (b)earthmoving; (c)all water diversions and impoundments; and (d)the size of area(s) to be worked at any one time. (e)An approximate timetable to describe the mining operation. The timetable is for the purpose of establishing the relationship between mining and reclamation during the different phases of a mining operation. An Operator/Applicant shall not be required to meet specific dates for initiation, or completion of mining in a phase as may be identified in the timetable. This does not exempt an Operator/Applicant from complying with the performance standards of Rule 3.1. If the operation is intended to be an intermittent operation as defined in Section 34- 32.5-103(11)(b), C.R.S., the Applicant should include in this exhibit a statement that conforms to the provisions of Section 34-32.5-103(11)(b), C.R.S. Such timetable should include: (i)an estimate of the periods of time which will be required for the various stages or phases of the operation; (ii)a description of the size and location of each area to be worked during each phase; and (iii)outlining the sequence in which each stage or phase of the operation will be carried out. (Timetables need not be separate and distinct from the mining plan, but may be incorporated therein.) (f)A map (in Exhibit C - Pre -Mining and Mining Plan Maps(s) of Affected Lands, Rule 6.4.3) may be used along with a narrative to present the following information: (i)nature, depth and thickness of the deposit to be mined and the thickness and type of overburden to be removed (may be marked "CONFIDENTIAL," pursuant to Rule 1.3(3)); and (ii)nature of the stratum immediately beneath the material to be mined in sedimentary deposits. (g)Identify the primary and secondary commodities to be mined/extracted and describe the intended use; and (h)name and describe the intended use of all expected incidental products to be mined/extracted by the proposed operation. (i)Specify if explosives will be used in conjunction with the mining (or reclamation). In consultation with the Office, the Applicant must demonstrate pursuant to Rule 6.5(4), Geotechnical Stability Exhibit, that off -site areas will not be adversely affected by blasting. (j) Specify the dimensions of any existing or proposed roads that will be used for the mining operation. Describe any improvements necessary on existing roads and the specifications to be used in the construction of new roads. New or improved roads must be included as part of the affected lands and permitted acreage. Affected land shall not include off -site roads which existed prior to the date on VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I 2 6.4.4 EXHIBIT D — Extraction Plan which notice was given or permit application was made to the office and which were constructed for purposes unrelated to the proposed mining operation and which will not be substantially upgraded to support the mining operation. Describe any associated drainage and runoff conveyance structures to include sufficient information to evaluate structure sizing. Prologue: Extraction of natural resources for rock products is essential to the well-being of a community. The urban infrastructure served by development of construction materials is a local and transitional benefit. The more remote these resources are from the need, the greater the cost to the private and public community. Unlike fixed urban impacts to the landform and area ecosystems, reclamation and restoration of extracted lands allow for preservation of natural buffers, and complementary alteration of both natural and human systems. Commencing on the family farm in 1948, the Varra family combines nearly 73± years of operational experience that serves as testimony to a history of sound and thoughtfully executed operations of this kind. For the Two Rivers Sand Gravel and Reservoir Project, lands not otherwise occupied for Developed Water Resources will be improved to the highest possible end -use. Post Extraction Uses beyond the Primary Use of Developed Water Resources will likely comprise continuing and diverse general agricultural uses; as well as possible light residential, commercial, or industrial uses; as determined by right, or as otherwise authorized by the governing authority. The restoration of above ground lands to native grasses and attending large water bodies are a baseline asset to area wildlife terrestrials and avifauna. Beyond good will, there are continuing landowner philosophical and economic enticements to further benefit area wildlife populations and diversity to further the value and enjoyment of the modified and surrounding lands. These efforts laid down over time involve the considerable experience of the landowner, staff, and other resources, including periodic consultation with the Colorado Division of Wildlife, the U.S. Natural Resources and Conservation Service, Colorado State University Natural Resource Departments and Extension Service, and a multitude of other natural resource professionals; including those highly qualified organizations and professionals who have already contributed to the Exhibits included under this application. Setting: The project area lies along and within the flood plain of the South Platte and Big Thompson Rivers. The predominant location of extraction is proximal to the geological delta found near the existing confluence of the two VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 13 6.4.4 EXHIBIT D - Extraction Plan rivers (hence, the Two Rivers Sand Gravel and Reservoir Project (Two Rivers Project; or TRP); and overlies bedrock that varies in depths as shallow as 20± feet in some locations, and more commonly 30-45± feet in depth from the surface. The permit area is flanked on its immediate western boundary by agricultural operations. To the north, residential uses expand, as remnant agriculture clings to the rising ground. Unfettered agricultural and rangeland uses still thrive as they extend beyond the permit boundary east, west, and south of the permit boundary along the alluvial influences of the two rivers. To the immediate east of the TRP, riverine lands are under active transformation into a created wetland bank. It should be understood that agricultural practices will remain active over the project area until converted by resource recovery and reclamation. America's first Transcontinental Railroad was being discussed in the 1840's, and surveyed in the 1850's. The railroads began the transformation of the American West on 10 May 1869 at Promontory Point, Utah. Railroad routes were being planned for this location and surrounding lands likely soon after the end of America's Civil War. The lines planned over the Two Rivers parcels were never built. Other lines were built nearby, like the Union Pacific's Dent line, that runs parallel to this day along the south bank of the South Platte River; and below the TRP. With area railroads came increased settlement, and with population the nature of the landscape became modified to complement growing market economies of agriculture and commerce since the early 1870's. We estimate the lands hugging the two rivers were farmed and the topography gradually manipulated for agriculture following the early establishment of Greeley and LaSalle, Colorado; in 1869-70. Area crops are commonly in corn, but this has not always been the case. We postulate that near the onset of the Twentieth Century sugar beet farming began to feed the demand of area sugar beet mills, further evidenced by speculative railroad routes over and near the parcel, itself. So, the appearance of the land that we see today, is commonly different than what it appeared at the time of settlement. In order to improve the area and extent of tillable lands, even early agricultural practices included landform modification to aid the plow. Prior floodplain modification is evidenced today by the historical placement of utilitarian levees flanking the existing agricultural fields along the outer cottonwood tree lined escarpments of each river. The levees are maintained to this day, and form perimeter access to the rivers and tillable fields. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 14 6.4.4 EXHIBIT D - Extraction Plan The later creation of farm to market County Road 396 eased access to the areas' agricultural fields, yet consequentially separates the fields at the TWP with its graveled surface, and subsequent rights -of -way and easements. The levees, public roads, cottonwood corridors and area tributaries are visible in the different map exhibit aerial images, and will not be impacted by planned extraction. All planned operations have conforming setbacks, and levee access will remain limited to wheeled vehicles during operations. Today, the upper terrace where extraction operations are planned, supports agricultural crops above the lower stream terrace formed further below and beyond the perimeter levees and cottonwood corridors that frame the adjacent active stream channels. The Fields designated for resource recovery (Central Field and North-West Field; as shown on Exhibit C - 2: Extraction Plan Map) lie over a nearly level upper terrace of the two rivers. The South Platte River borders the southern and eastern extent of planned extraction, and the Big Thompson River intersects the permit area north of the Fields. The stream terrace itself is a riparian area that supports on its flanking escarpment an uneven aged stand of Cottonwood trees. The uneven aged trees suggest this segment of the river has experienced some scouring in the past from periodic, yet commonly limited, flooding; which encourages natural regeneration of Cottonwoods. To determine the influence of past activities on groundwater, twelve (12) Piezometer Wells were located along and within the entire TRP boundary. Groundwater level information here, is based on 5.75 years of continuous monthly measurements at twelve (12) piezometer locations identified on the included Exhibit G: Water Information Map. Recorded groundwater depths vary in elevation below the surface, with a general (weighted) mean depth of 8.40± feet. Groundwater elevations are influenced by crop irrigation practices that run generally from April through September, and may occasionally lag into the middle of October. During this time groundwater depths may be skewed higher in elevation to the extreme North-eastern extents of Central Field, yet with few exceptions, groundwater elevations over the entire site remain significantly deeper than 5.11± feet from the surface, year over year, over the entire TRP area. Using the approximate surface elevation at the extreme eastern boundaries of North-West Field and Central Field, and noting that groundwater fluctuations will commonly meet at 8.40± feet below the surface, yet rarely rise more than VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page IS 6.4.4 EXHIBIT D - Extraction Plan 5.11± feet from the surface, we determined the Static Water Level using the upper limit of 5.0± feet. The Cyan colored contour shown on Exhibit G: Water Information Map represents the Static Groundwater Elevation at 4675' at North-West Field, and 4673' at Central Field. Since completed reservoirs will be lined to meet State of Colorado Water Resources specifications and requirements, and since lined basins will ultimately equalize with the surrounding groundwater elevations, the Static Water Levels shown should reasonably reflect those of the both the lined or unlined state; and represent a proper reflection of the optimal surface area of the water over the finished basins. Raptor Materials, LLC has sufficient water to meet the circumstances and obligations of both the lined and unlined states; and as reflected under Exhibit G: Water Resources Information; until and unless the reservoirs have an approved liner, the Operator will dedicate sufficient waters to secure the reclamation of the resulting basins in the unlined state. Planned Field Activities: The 409.23± acre parcel boundary forms the permit boundary, as reflected on exhibit maps. All lands under its direct control within the 409.23± acre permit area, are affected lands under C.R.S. 34-32.5- 103(1), respective of this permit application. As a result, any changes required in the nature of planned extraction or reclamation will be made only through the Colorado Office of Mined Land Reclamation (OMLR), by Technical Revision only. If lands are needed beyond the designated permit boundary, those lands will be secured for the active OMLR permit by Amendment. Within the permit boundary, there are two* (2) identifiable areas designated for primary extraction, the description of which will help to explain the nature of planned extraction and reclamation. The Primary Areas of Extraction are as follows: 180.76± Acres 53.30± Acres 234.06± Acres 175.17± Acres 409.23± TOTAL Primary Extraction (***) Central Field: 20-30± years (2023- '53) ** Primary Extraction North-West Field: 5-10± years (2048- '58) ** Total Primary Extraction * Affected Lands beyond planned extraction limits (*) NOTE: The third area of secondary extraction is limited to approx. 5.60± Acres for a Plant Processing/Stockpile Area Pond, as further indicated, below; and is not included in this total. (**) NOTE: Final reclamation will add up to five (5.0±) years to the anticipated Life of the Mine, subsequent to completion of extraction and removal of all marketable materials. Life of Extraction is an approximation, and could lengthen or shorten the overall life of the mine depending upon market conditions. (***) NOTE: Of the 180.76± Acres of Primary Extraction, 4.09± Acres comprise an existing Farm Yard & Structures with residence. These facilities may be leased or VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 16 6.4.4 EXHIBIT D — Extraction Plan otherwise utilized as an Office and Support/Storage facilities for Operations, potable water and sanitation. Lands identified within a designated Extraction Limit may not be extracted, including the Farm Yard area, as circumstances warrant according to the discretion of the Operator. Of the outlying 175.17± Acres: 15.76± Acres = Plant Processing/Stockpile Area 5.60± Acres = Secondary Extraction - Plant Processing/Stockpile Area Wash Pond 21.35± TOTAL The remaining 153.82± acres of lands within the permitted limits may comprise planned or existing permanent access roads, levees, previously affected areas, and areas of minor to no disturbance (including public transportation corridors, right-of-way's, easements, permanent structures, river and stream terrace and cottonwood corridor buffer areas), or other farm land features or structures; or as otherwise determined from included maps and aerials. These lands may also include essential support operations, including: parked vehicles, equipment, plant site equipment and processing stockpiles, etc., not otherwise explicitly indicated or shown, but reasonably associated with operations of like kind, and may be varied in location and extent over time; or otherwise, field fit within the permit boundary as warranted. Wetland conditions appear confined within portions of the stream terrace and bank -full stage of the rivers, and along segments internal to the Evans Canal. Extraction will form a depression (basin) within the floodplain as shown in Exhibit C-2: Extraction Plan Map. Temporary above ground fill may occur within the floodplain, and as part of this permitted activity, provided the above ground volume does not exceed the below ground volume created by extraction. All product stockpiles and processing will occur within the city limits of Evans under this application, and North and outside of the floodplain boundary of the 100 -year floodplain of the Big Thompson River. The floodplain extent will be visually marked in the field to better assure the integrity of the floodplain. Material transport of raw materials from extraction locations to the plant site will occur via conveyor (see route on Exhibit C-2: Extraction Plan Map). This will in turn serve to minimize impacts to area transportation corridors. The actual location, extent, and nature of the conveyor systems not otherwise designated in this submittal will be provided as updates in the required OMLR Annual Reports. Known structures and landowners, including above and below ground utility owners, located on and within 200± ft. of the permit boundary, are shown on Exhibit C-1: Existing Conditions Map. Exhibit S: Stability Analysis - provides VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 17 6.4.4 EXHIBIT D - Extraction Plan certification from a registered professional engineer that these structures will not be harmed by planned extraction profiles and extents. 'For lands within the Extraction Limits, only those structures, easements, and rights -of -way shown in Exhibit C-2: Extraction Plan Map, are anticipated to remain from those shown in Exhibit C-1: Existing Conditions Map. If changes to existing or possible revised structures, easements, or right-of-way are in any manner retained, or where they might occur subsequent to OMLR approval of this application, then a Technical Revision will be submitted to update Exhibit C-2: Extraction Plan Map. All established setback distances from planned activities to any remaining features will be maintained regardless. Operations or related Processing Areas and Wash Pond are not intended to affect existing structures, Easements, or Right -of -Ways within the Planned Extraction Limits identified as remaining and are designed to avoid and retain any remaining structure, Easement or Right -of -Way on the surface, and subsurface. Future agreements may be reached allowing mining in areas currently identified as being restricted to mining containing certain structures, Easements or Right -of -Ways. Exhibit C-1 shows and identifies all these features understood by us, and the respective Surveyed information, and correlated Observation and Title Work upon which they are based and represented on the attending Maps. The Maps are not Surveys. They are Maps and as such, they comprise a reasonable representation of all site features, but must not be relied upon by themselves exclusively for location purposes. Maps and features are not a substitute for field identification of underground structures and will rely upon location services of the 811 service. Setbacks where required will be based on the actual field locations of site features. Exhibit C-2 shows the remaining Oil Wells and Lines within Planned Operations at the time of the Submittal. Any revisions, additions, or modifications of residual Oil Wells or Lines will be avoided as represented on updated Maps and Revisions to the Permit, and consistent with Setback Distances identified in this submittal. Removal of any Existing Structures such as the Oil and Gas structures and or lines, will be updated on required Annual Reports, or by Technical Revision, as warranted, or as otherwise directed consistent with Colorado Statute. Access to the Theater of Operations: Entry into the permitted areas is dependent upon the needs and necessary management of continued agricultural activities during operations, as well as essential management and 1 Adequacy Item 18 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page IS 6.4.4 EXHIBIT D - Extraction Plan mobility within the active areas of extraction, processing; and correlated need for transportation of human resources, equipment, and product. Human resources for operations, heavy equipment, and haul traffic will occur based upon the desired and dynamic activities necessitated by time and circumstance within the designated Fields. Access points for continued agricultural, extraction, and plant site operations are shown :; on Exhibit C-2: Extraction Plan Map, as follows (NOTE: Access purpose and usage may change in time from that indicated here -in. Also, General Existing Dimensions and length of existing access roads are represented in the aerial images on the Exhibit Maps relative to the Access locations detailed, below. Modifications may occur as needed and will be reported in OMLR Annual Reports.): * Entrance 1: Farmstead entrance. Limited Access. Note: Visitors will first access operations by checking in at an established plant scale -house, not here. Entrance 2: Primary Access to the lower boundary of Central Field. Entrance 3: Primary Western Access to the North-West Field. Entrance 4: Primary Eastern Access to the Wash Pond and designated Plant Site. Entrance 5: Adjacent Parcel Existing Access. Entrance 6: Oil & Gas Access into the Western Section of Central Field. Entrance 7: Primary Eastern Access to the North-West Field. Entrance 8: Primary Northern Access to Central Field. Entrance 9: Primary Northern Access into the designated Plant Site location. Entrance 10: Internal Access from Adjacent Lands. Entrance X — Agricultural/Mechanical Entrance WV — Agricultural/Mechanical — Westervelt R -O -W Access to adjacent Wetland Bank Existing roads outside of the permit boundary are shown on Exhibit C-1: Existing Conditions Map. Existing on -site internal access roads are also visible to scale in the aerial information provided under Exhibit C-2: Extraction Plan Map and other map exhibits included with this submittal. In general, Operations will predominantly utilize unmodified existing agricultural field access roads (unless otherwise indicated), which will themselves be subsequently extracted in time where they fall within the extraction limits shown on Exhibit C-2: Extraction Plan Map. No other defined roads within the Extraction Limits will occur except for the temporary paths created by extraction equipment, or otherwise determined by subsequent Revision to the permit. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 19 6.4.4 EXHIBIT D - Extraction Plan All existing agricultural roads outside of the designated extraction limits will be retained according to the desires of the landowner. The same shall form part of the final end use of the reclaimed lands, unless otherwise indicated in this submittal or by subsequent permit revision. For purposes of this submittal, all lands within the indicated permit boundary will be considered affected lands, but only those locations between the existing access roads, and which otherwise remain above the anticipated static water level of the resulting basins, will be soiled (where soil is absent) and seeded to establish vegetation consistent with the approved reclamation plan. Area and Site Soils: Soil formation surrounding and within the project area varies according to diverse geologic, natural, and man -caused influences. The United States Soil Conservation Service, Soil Surveys, are the foundation source for understanding area soils as identified on Soil Survey Maps by their Soil Unit Number. Unit 3 Soil formations for Weld County are not easily typified or quantified as other soil units, for a reason; natural and man-made alteration and use of the land over time. Planned extraction limits will affect predominantly Unit 3 Soils. Extract from Exhibit I/J. Unit 3 soils commonly form within floodplains. As a result, differing states of soil formation may exist within the soil unit designation; such as soils with little horizon development like Entisols and Inseptisols. Mollisols with deep well -developed horizons may exist in the minority and the near fringe of planned extraction. Refer to graphic above, and bleow. Enceptisol Inceptisol Molisol VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Pag 10 6.4.4 EXHIBIT D - Extraction Plan Soil Morphology With over a century of agricultural manipulation of area agricultural fields, prior mixing or importation of soils for land leveling, or flood plain management in the creation of levees, may have dramatically altered the original native soil profiles and properties. The native A profile of the upland terrace found within the agricultural Fields at the TRP, is predominantly modified as a plow (Ap) layer of 6.0± to 8.0± inches. The historic practice of incorporating manure into the plow layer should have served to maintain the organic base and quality of the cropped soils and accelerated soil horizon formation and development where it was lagging. Since the cropped soils have been irrigated, care should be taken not to salvage soils greater than 12.0± inches in depth to avoid mixing of potential accumulated salts. Generally, total soil depth (including all soil horizons) over the property may vary from approximately zero inches to four [4.0±] feet, yet predominantly having a shallow Ap plow layer of six to eight [6-8±] inches, lacking a B profile and having the potential for a mixture of silt, clay, or gravel outcrops over random areas. Gravel depth may occur from the surface to the underlying Fox Hills Sandstone varying at approximately 30.0± to 45.0± feet over the entire property. Suitable soil in excess of that needed for reclamation will be made commercially available to meet area infrastructure and residential demand. Soils found within the entire project area are described more thoroughly under Exhibit I - Soils Exhibit, and the attending Exhibit I/J - Soils and VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 6.4.4 EXHIBIT D - Extraction Plan Vegetation Map, shown not to scale, above. Additional geologic considerations are also included under Exhibit S - Stability Analysis. Area and Site Geology: The area geology is typified by mixed alluvial and aeolian development, that is commonly alluvial in nature at lower elevations. As viewed in the Geologic Timeline and shown in Figure 1, below, the aggregate deposit is found between the Laramie and Fox Hills Sandstone formations, both formed during the Upper Cretaceous Period nearly 65 million years ago. The alluvium of the river valleys and aeolian sands that cap the hills formed of the Laramie formation north of the permit area are more geologically recent, developing during the Quaternary Period. PERIOD EPOCH 1 eater nary Tprtia r i tie a Massie. s Phone kx eri e MFL .IONS OF YEARS AGO HOW IjEe It 0.1 0.6 16 5,3 112 116.4 73.7 2831 33) 4J.A S 54 i5 c3 144. 159 tan 206 221 242 .246 Geologic Time - Livescience.com VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 12 6.4.4 EXHIBIT D - Extraction Plan Figure 1: Area Geology Map The areas of extraction are in the alluvium whose general morphology, area and extent are better understood in Figure 1 above, and 2 and 3, below (Colorado Geological Survey). • • 41r•.fir - - if - . • i:i. . L ; • 'r • • �L: '-a • II" OM 11 an -.le - . - 1- r- . -z• ,�' 417 ;nazi; IV Li • • — —S ke ,!- , • a e• • - S' : t� -..1 _ .a • 1 Lion r 1 1 . 11a-- .1.1.' m -- Jut a- •. .... • • m•�` it ... . .-1-„1.� .. •gam- r•.4.• !1 r▪ wlr • n• '• i tall �" - - Sal . • p r . ' g •,.tip ▪ - a of Sc. " 1! 1' _ J 1 , .0_ •. •-i- r•1^ n - • ., 9 r ,, ._ • a . • - - - - I. 1 O` ' 0 1 �;• a 1 11 B,• - a a R• ^ n i. "r. I Y 1 Ua a .a,�• 1. i - ,k u ,,.a • p Y• .. !al's • 1 • • •.Y — o .i �• w IS -• - f- . ..• a .��.. d •- •• a ,1 a• - a a ▪ .- • - 1 �� ' / 9 •'.t. a Ji.• .'F ▪ •. •- - • -•, • . — a ` . ,'• d. ' " • ' • - - �/• 'a. '`-! Fz s L. • —.' _.. i.ii• ,� , - - • r-' ■ .. "f• �.•1•• • Tau a - . • - a - I. � c ,i. .. e ti- a. . .-i e _ r •.r SA.' •. �. ,.��.i�sa - i . ;d alp m T� Y' v 1 x o • , - _ e •'.•.-r-ay a s: e cm c• r s••- -c1 , r• •z.. • a. tl e9 ••- • N, •'• • • 0�• f S. - .. .1• • - - Figure 2: Area Geology 3D Oblique View - Ai *, _ ,j ' • • 1" -• •"au it •• 7i 1 a 1 "9' .- 1 1. • IT. : I 1 ••.. • . e , • Aa' r' "F • •-u • 'a _ • *No • -r".• ._. '• -i.n s-• ▪ •• i • .• L.� •• • '-. 1• It es I a • r! .. • so. _ a 1 • 6R C.� 1 ter, • ' ., •. z & a. -• -arn °• j'_a. at Y -• • '7 • . b ik W • ,41'_ VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 1 13 6.4.4 EXHIBIT D - Extraction Plan CORRELATION OF MAP UNITS SURIICIAL DEPOSITS H i A DE DEPOSITS DEP OSE!S GRAVEL EECLI: i_'1 DEPOSITS DEPoSIT'S, of .. 1 ,:: ; _- ' a I . Qa Q a L. _ . Oct- _ . . • !- _ . - ` . f_ -3 1 ag3, unconformi O q 3 'Inconformity CI e _ -o _ cc,aue Figure 3: Surficial Deposits relative to areas shown in Figure 2, above. The aggregate deposits of Qal and Qa2 (Figure 3, above) form the bulk of the deposit planned for extraction. Depths vary by field from approx. 30 to 45 feet. Depths are shallower as the adjacent hillside rises to the north; while the deposit dips deeper toward the South -East of each designated Field. Soil Salvage: Resource recovery will commence by first removing the upper [A profile/plow layer] six to twelve inches of soil [six (6.0±) inches typical], combined with existing grass or crop stubble. Removal will utilize scrapers or excavators, aided by dozers where necessary, and hauled to the Northeast Section of Central Field. All extraction and surface related activities detailed in this application will occur under an approved Fugitive Dust Permit issued by the Colorado Department of Public Health and Environment (CDH). Until resoiling activity occurs, where harvested soils have been stockpiled and remain undisturbed for reclamation or sale, they will be seeded with the mixture specified under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. A stabilizing cover of native vegetation may take up to three years to fully establish the desired cover. In the event the native seed mixture fails, an optional mixture of predominantly introduced species will be used as a fall back to better assure a stabilizing cover of vegetation. Still, using the VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 14 6.4.4 EXHIBIT D - Extraction Plan preferred native seed mixture offers opportunity to gauge the potential performance of the selected species prior to utilizing it over larger areas requiring reclamation later in the life of the resource recovery operation. Once vegetation is established over the initial reclamation soil stockpiles, they will likely remain untouched for the life of the operation until final reclamation of remaining affected lands takes place. Where concurrent reclamation is possible, operations will utilize soil in an over the shoulder method when practical. In this manner, reclamation is expedited without increasing soil stockpile volumes while reducing expenditures related to labor, handling, and time. Soil salvaged as stated above will range six to twelve inches in thickness. Resulting volumes of salvaged soil will range from 145,800± - 291,600± cubic yards for Central field, and from 43,000± - 86,000± cubic yards for the North West field. Salvaged soil will generally be stockpiled on top of the Westervelt soil storage area in the North-East section of Central field. Smaller short-term stockpiles may be created along the pit edges where regrading is imminent or in progress and resoiling will follow. Resoiling oiling volumes required above the waterline of the lined water storage will require much less soil. The resoiling areas are estimated at 11.82± acres for Central field and 4.80± acres for the North West field with volumes at a nominal six inches of soil cover at 9,535± and 3,872± cubic yards respectively. Excess soil not needed on site may be sold. Dewatering: As extraction activity progresses into the aggregate profile, groundwater must generally be removed in advance through the use of pumps and subsequent discharge into area tributaries. A complete dewatering evaluation was performed by AWES in their report of 27 July 2020, as provided at the back of Exhibit G: Water Information. The report concludes that 'the results of analytical and numerical solutions indicate that the proposed mine dewatering activities will not adversely affect the regional groundwater hydrology.' The reader is further assured that all discharge of waters will be conducted under an approved CDH discharge permit. Initial dewatering of the property in preparation for extraction and resource recovery will occur by establishment of a dewatering pump and/or well in the Southern boundary near an existing agricultural pond. The point of discharge is on Exhibit G: Water Information Map. Other discharge locations may occur in time as needed and otherwise approved under the applicable CDH 2 Adequacy Item 23/32 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 15 6.4.4 EXHIBIT D - Extraction Plan discharge permit requirements. Subsequent CDH approved discharge locations will be field fit and the location updated in the following OMLR Annual Report. Active Resource Recovery: Following soil salvage, the balance of the extractable deposit will be removed to the depth of the unconsolidated or weathered bedrock, transported by conveyor to the plant site pit run, and subsequently manipulated as desired by screening, crushing, washing, and other methods to size and properly dimension the earth product into diverse merchantable materials for sale. Resource recovery will commence radially North and East from a point near the existing pond and planned first discharge point shown near the Southern boundary of Central Field. There are no fixed sequences or phases scheduled as part of the extraction plan. Instead, Fields are used instead of Phases to describe the activities, since each Field can be accessed concurrently instead of sequentially with the other; as reflected or otherwise updated as part of required OMLR Annual Reports. Under this method, extraction is 'pulsed.' As such, the rate of extraction and subsequent reclamation will slow or quicken according to influences of the markets, weather, and internal logistics. Flexibility in Operations encourages better outcomes when adapting to changing circumstance or unexpected field conditions, and may involve actively working different fields or different parts of the same field as necessary. 'For Two Rivers, there are four Fields, intended as sequential areas of extraction unless market demands warrant concurrent development: • 127.10± Acres - Central Field — Center Section • 23.19± Acres - Central Field — North-East Section • 30.47± Acres - Central Field - West Section • 53.30+ Acres - North-West Field Generally, flexibility aids integrity of operations and encourages optimizing operational activity and subsequent reclamation of affected lands. Therefore, any method that accelerates the extraction timeline will be utilized, and should be encouraged to better engage the unpredictable elements and variables that reasonably affect the capacities of the Operator. Exhibit C-2: Extraction Plan Map, shows the location and planned extraction limits, general direction of extraction, and related features described above; along with features made obvious in the included aerial image of the permit location and surrounding lands. 'Adequacy Item 17: Aspects of detail required. Other aspects addressed elsewhere. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 1 16 6.4.4 EXHIBIT D - Extraction Plan 'Exhibit L: Financial Warranty Map, shows Initial Extraction proposed to begin in the yellow hatch area shown on the Exhibit L Map, comprising 16.26± acre. The direction of extraction will follow the perimeter of the extraction limits over approximately 75.45± acres in order to establish the perimeter keyway (dewatering trench') for the 127.10± acre Center Section of Central Field. The perimeter extraction will leave a 51.65± acre Core, that may be extracted as needed as keyway drainage capacity allows. The Initial Extraction area is practical as it has no encumbrances and is adjacent to the existing pond. The initial extraction area is bordered to the South along a near 800± foot section of oil and gas line that is pending removal; along with the two oil and gas wells, also pending removal (refer to Exhibit C for ownership details). If or while this infrastructure is still in place, extraction will not occur within 10 feet of these lines, or 25 feet from the wells, as indicated in the setbacks detailed below. Below this gas line is an existing pond and well that will be used as a Settling Basin Area, containing at present a solitary settling basin and pump as a point of discharge of groundwater. This pond may be expanded or added to below this line and may then be extracted itself once discharge is discontinued for Central Field Operations. Perimeter Keyway Extraction will maintain a perimeter slope no steeper than 1.25H:1V, except for the perimeter shown in red along it's extraction limit, and respective toe where cut slopes will not exceed 2.00H:1V; as indicated (refer to Exhibit S: Stability Analysis for additional information). At the toe of the cut perimeter slope is the keyway that runs below the extracted deposit of the basin, into the bedrock, which allows the subsurface waters to flow to the settling basin and discharge pumps necessary to keep the cut basin dry during a time of extraction and reclamation of the affected perimeter slopes. The keyway dimensions may vary more or less from 4± to 8± feet in depth and 4± to 16± feet in width. Extraction must be broad enough to allow equipment to safely approach the toe and excise the bed dimensions where the resulting channel is sufficient to convey the groundwaters to the settling basin for discharge. Please Note: The graphic representation of the Perimeter Keyway Extraction and Core are idealized, and may vary in shape, size, and location presented. Annual Reports will report on the nature and extent of affected lands and more properly reflect actual conditions on the ground in a given year of operations. 4 Adequacy Item 17: Modified from first adequacy response to better define the mining and reclamation plan and reference a schedule in Exhibit E. S Adequacy Item 15: Keyway clarification VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 17 6.4.4 EXHIBIT D - Extraction Plan At anticipated production levels and production only from the Center Section of Central Field, extraction of the remaining perimeter excavation could take 7-8± years. Extraction of the core could then commence and take 6-8± years, overlapping with initial development of the next field. With sequential development, extraction of the North-East Section of Central Field could take 4- 6± years, the West Section of Central Field 5-7± years, and the North-West Field, 8-10± years. Please Note: The time periods will depend on the actual rate of production required to meet market demand, and the average annual advance may also vary with thickness of the sand and gravel and ground conditions. Some flexibility may also be exercised to optimize operations around or through existing infrastructure if scheduled for removal. Table E-1 provides a projection of mine development and regrading/reclamation. The plan as described in this Exhibit D and also in Exhibit E, is a forecast and may vary according to market conditions with mining and subsequent regrading occurring faster or slower, sometimes significantly so. The geology may also dictate changes in the rate of extraction. If efficiency demands in a higher production demand scenario, up to four separate areas could be developed in the manner described simultaneously. Such changes may happen quickly and would be addressed in the Annual Report. ()In discussing this flexing of production and scaling operations up or down with OMLR staff, a concern was raised as to impacts on mule deer habitat if there were separate production areas with a larger area under active production. This has been addressed as having minimal impact in a letter from Ron Beane, Senior Wildlife Biologist with wildlife consultant ERO Resources Corp attached as an addendum to this Exhibit D. Additional information is provided under Exhibit C-1: Existing Conditions Map; which shows all known current and active significant man-made structures located on or within 200 feet of the permit boundary detailed under including creeks, roads, buildings, oil and gas facilities [such as tanks, batteries, wells and lines], and power and communication lines and support structures, easements and rights -of -way; located over the permitted lands or within 200 feet of the same. A listing of the adjoining surface owner's names and addresses located within these areas are listed under Exhibit C Text, correlated with those shown in the afore -mentioned Exhibit C-1: Existing Conditions Map. The extraction limits assure through the use of setbacks that other interests are not affected by planned extraction. Extraction is set back uniformly at a minimum 10.0± feet from the edge of property lines; easements and rights -of - way; underground gas lines or other underground facilities, irrigation ditches and seep ditch, wells and other structures. 'Minor variations may occur in the field over time from those represented on Exhibit Maps. The plans detailed in 6 Adequacy Item 17: Wildlife concern Adequacy Item 21 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION i 18 6.4.4 EXHIBIT D - Extraction Plan this application are based upon future events for which minor or temporary departures at any point in time may be evident. To the extent any significant departure in the field occurs in a time and manner not otherwise anticipated in these exhibits, the operator may cure by self -inspection, by observation from OMLR inspection in a timely manner, or by operator -initiated Revision to the Permit or otherwise via clarification in attending required OMLR Annual Reports. Extraction will not occur closer than 125+ feet from the face of a residential structure; unless there is a written accommodation with the owner of the residential structure that allows extraction to occur within a closer stated limit. Extraction will occur no closer than 25± feet from well heads and related above ground facilities. Extraction around well heads will be concurrently backfilled to maintain a 100± foot buffer from the balance of extracted lands. At all times, safety will take precedent and over -ride all other conditions in time with a matter of safety or emergency respective to any and all aspects of the approved permit. To minimize the potential of river capture, planned setbacks from the two rivers was evaluated by Flow Technologies (refer to report at the back of Exhibit G: Water Information - titled: Two Rivers Riverside Berm Failure Analysis and Flood Control Mitigation Plan' of 22 January 2020). The report finds: `... that head cutting/erosion will not progress through the full length of a 100 -ft riverside berms. It is important to note that should a flood occur that results in head cutting/erosion of a riverside berm, Varra Companies, Inc. will act diligently to restore the damaged areas to pre - flood conditions. As mentioned, this analysis is conservative and riverside head cutting/erosion is based on the 100-yr flood. There is a small probability that such a flood event could occur during extraction and when the pit is dewatere d. During extraction, a predominantly vertical advancing pit wall (the extraction front) is not anticipated due to the use of excavators in the removal of the material deposits. Excavators provide a great deal of control over the extraction process. The maximum length of the extraction front will likely never exceed the length of one side of a quarter section of land, or 1,320± feet, or less; in any given direction. The advancing front will result in a moving face with a slope typically equal to or flatter than 1.2 SH:lV, and commonly not greater than 1.2 SH:1V along the perimeter of the extraction limits to depth. 8 Adequacy Item 22 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 19 6.4.4 EXHIBIT D - Extraction Plan The exception to cut perimeter slopes is shown with a distinct Red Boundary on Exhibit C-2: Extraction Plan Map, where cut slopes will not exceed 2H:1V in order to maintain integrity and stability along that designated perimeter area (refer to the AWES Slope Stability Analyses of 23 December 2019, located at the back of this exhibit). Internal transport of extracted materials to conveyor systems or other internal transport; or otherwise by approved public roadways, will be used in the transportation of extracted materials to the designated plant/stockpile location, described in greater detail, below. Acreage to be affected during the first year of extraction activities include the establishment of the initial Wash Pond and attending Settling Pond(s), Plant Site, and Initial Areas of Extraction and attending means of transportation by ground haulage or conveyor. While the acreage required for the Plant Site and Wash Pond are not expected to change, the Initial Area of Extraction will expand until concurrent reclamation follows as each location is exhausted of resource. Although initial extraction may otherwise result in temporary slopes up to I.25h:lv, all cut slopes will be backfilled with unconsolidated bedrock, overburden (on -site unmerchantable excess materials, or imported inert materials) and soil to advance the reclamation and completion of the desired basins. Final reclaimed slopes and grades will be concurrently established where practical to 3h:lv, or flatter, and at a minimum from 5± feet above to 10± below the expected water level of each location of extraction, and to the basin floor. Concurrent backfilling and grading of cut perimeter slopes, while desirable, may be obstructed in time and extent by the need to maintain keyways and basin discharge during extraction. Backfilling of slopes can only occur once enough of the floor is exposed to facilitate backfilling and finished grade of extracted basin slopes without interfering with basin discharge operations. This makes concurrent backfill difficult to accurately forecast. Regardless, any completed slope remediation will be indicated in any subsequent OMLR Annual Report. Cut slopes will cause direct precipitation to drain internally into the resulting basins and are not anticipated to result in any off -site impacts due to erosion or stormwater runoff. The gentle to near flat topography of the area landscape tends to aid in overall stability above the planned areas of extraction. While some erosion of resulting basin perimeter slopes will be evident subsequent to extraction, the advance of reclamation activity over affected lands will provide cover for both near and long-term stability of those lands remaining above water level of the finished basins. All completed slopes VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 1 zo 6.4.4 EXHIBIT D - Extraction Plan above the anticipated static groundwater elevation will be soiled, seeded and stabilized as provided for under Exhibit E - Reclamation Plan. Of the total 234.06± acres of potential extraction, the resulting basins will function as multiple -use reservoirs with a slightly fluctuating combined water surface area covering 218.44±. The remaining balance of 3 7.9± acres of land above the anticipated high-water mark of the reservoirs, and not otherwise committed to existing or planned structures or infrastructure over the parcel, will be stabilized with vegetation; including the anticipated 16.50± acres of basin slopes reflected in the total, and 32.3 acres requiring resolling. NOTE: Shoreline irregularities and fill to establish and enhance the aesthetic and end -use functions of the resulting basins shown on Exhibit F: Reclamation Plan Map, are illustrative only, as this effect as to location and extent will be field -fit where practical, and may substantively different from that portrayed under the application. The actual location and extent will be identified in subsequent OMLR Annual Reports, and absent there, at the time of any applicable release of a location in part or whole from the permit. Since representations cannot be accurately portrayed in advance, Exhibit F simply identifies the near maximum extent [typical] of the resulting basins or ponds and the potential for shallows during lining and finished grading. The estimated timetable for extraction, commencing approximately spring to winter 2023; is estimated to take 25-30± years combined, or longer, followed by an additional five years to complete reclamation; or a total estimated life of the mine of 30-35+ years; ending approximately winter 2053 to 2058. This is a life of the mine operation and all timetables are estimates and may prove shorter or longer than stated. The final determination will occur five years after the deposit is exhausted and all marketable product has been removed and necessary infill completed at the location to the point of final reclamation as approved or modified under the terms of the permit is completed. This submittal is unable to fully forecast the maximum extent of affected land expected at any given point in time, beyond an annual basis. As operational extraction and reclamation efforts will vary annually, the timing of extraction, reclamation, and life of operation as forecasts must be based on an initial estimate [refer to Exhibit L - Reclamation Costs], then subsequently verified and adjusted as reasonably determined at the time of the required OMLR Annual Report. If justified by field conditions, a rider to the warranty would follow in due course to reflect current or forecast conditions where such conditions cannot be reasonably attenuated in a timely manner prior to the due date of the next year's Annual Report. This VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 21 6.4.4 EXHIBIT D - Extraction Plan will serve to assure flexibility and confidence in continued operations until completion of the desired end use. Additional information on the reclamation and restoration of affected lands is identified under Exhibit E: Reclamation Plan. All reclamation will follow guidelines established under Exhibit E - Reclamation Plan and Exhibit I/J: Soils and Vegetation Information, until and unless otherwise revised. To the extent possible, pond bottoms will be left rough, with the possible introduction of logs or other non -putrescent inert material to aid in aquatic habitat and cover [Refer to Exhibit H - Wildlife Information]. Plant Site Development & Operations: Plant operations are generally comprised of portable equipment. A small wash pond will be established near the onset of extraction operations as shown in Exhibit C-2: Extraction Plan Map. Deposit materials are predominantly transported or conveyed from the extraction areas to the plants or surrounding yard, where subsequently processed and scaled for sale. Pit -run (unprocessed materials) may also be loaded and transported directly from the extraction areas to area markets as needed and where appropriate. Plant Site operations may also receive and process materials, and utilize fresh water supply, sourced from locations outside of the permit area or planned areas of extraction. Provisions for a material processing plant may at some point be joined by complementary processing that may include periodic use of on -site recycling facilities. While recycling activities may occur within the approved plant site/stockpile location; concrete and/or asphalt batch plant facilities and locations are not presently determined or sought at the time of this submittal. Due to the extended life of the mine the Operator desires an essential flexibility to complement future area needs according to permit requirements and approvals applicable at the time should such facilities be sought. Any facility development of this kind will be determined at that time as identified in a later Technical Revision to the OMLR under the approved permit. These potential activities are mentioned here solely for purposes of transparency in establishing these activities as acceptable, normal, and necessary activities to meet and facilitate the delivery of essential construction material needs of the area which may occur over time during the life of the approved OMLR Construction Materials Permit Operations. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 22 6.4.4 EXHIBIT D - Extraction Plan Initial Plant Site Theater as seen in Exhibit C-2: Extraction Plan Map WASH POND 5.60± ACRES With the exception of the wash pond, whose margins follow existing surface elevations; all plant site processing activities will occur on upland areas outside of the existing 100 -year floodplain. These lands occur north and north-west of the existing Evans Ditch as it courses winds north of the Big Thompson River. Plant activities will require a wash plant and attending wash pond to recycle wash water and receive discharge silts and other reject fines from the washed product. Plant and Wash Pond areas are identified on Exhibit C-2: Extraction Plan Map. The wash pond will function as recycling wash water and receiving basin for reject fines for the intended Plant/Processing activities. Since the basin functions in a closed system, it will not require dewatering. Once the wash pond is established, wet plant operations can be created and join any dry plant activities in progress. Dry Plant operations can be readily established since water is not integral to their operations. Once established, wash pond water will function as a closed system. Settled materials from wash Ponds will be utilized as product or for reclamation as desired. Plant equipment will include, but is not limited to, a crusher, screens, and conveyors, scale house and scale, and attending equipment. Resulting stockpiles of pit run and processed products may be temporarily stockpiled here with processed stockpiles, or combined as needed, until transported to market. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION I 23 6.4.4 EXHIBIT D - Extraction Plan 9The conveyor will be set on an elevated structure at varying heights to be situated about the 1 in 100 -year flood level. An average height of 7 feet is expected. The conveyor will be supported by legs at intervals of approximately 40 feet with typically 6- x 2- x 2 -foot concrete blocks sitting on ground surface used as necessary to anchor the legs. The conveyor will span the river channel and metal (or other appropriate material) pans will be installed under the conveyor structure to prevent spillage into the river. The design will be similar to other Raptor locations where an extended span has been required to cross a county road. Final conveyor specifications are to be determined however belt width is anticipated in the range 24-36". Ultimately, once the wash plant activities near the completion of extracted deposit material, the closed system wash pond will fill with silt and be revegetated in a manner consistent with Exhibit E - Reclamation Plan. Interim clean out of the wash pond will occur until that point, returning the inert materials to the bottom of exhausted pits, or utilizing it in part or in whole as product, or for purposes as substitute soil, soil additive, or as subsoil for reclamation. Plant and material processing activity will divide materials into diverse and dynamic product stockpiles that will come and go with unpredictable variations in sale and production. To the extent possible, product material will surround plant activities to further lessen visual and noise impacts to surrounding properties. Plant placement will assure that plant noise is well below that of the nearby traffic. Relative to noise, traffic travelling on area roads at 55 mph or above is approximately 70.0± decibels within 100 feet from the centerline of the Highway. Noise at ground zero at a cone crusher, as measured by a hand- held meter, is at 80.0± decibels, dropping to 70.0± decibels at I00.0± feet from the center. The level drops an additional 5.0± decibels for every 100.0± feet from the center of the crusher and surrounding plant noise, achieving residential background levels at a total setback of 400± feet. Backup sirens and heavy equipment averaged 60.0± to 75± decibels, with similar decreases in decibel readings from the source measured in a manner similar to that indicated for the crusher and plant equipment sources. Plant stockpiles will aid muting of plant sourced noise just as noise levels at areas of extraction are buffered with increasing depth of extraction. The location of the portable scale and scale house and correlated internal traffic at the plant site location will vary depending upon production levels and areas needed for product stockpiling. Regardless, the scale house will be 9 Adequacy Item 24 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 1 24 6.4.4 EXHIBIT D - Extraction Plan located along internal paths for haul trucks, where finished material will be weighed and disembarked to help build the urban matrix of roads, highways, foundations, and desirable neighborhoods communities most desire. For a diverse list of products to be extracted and/or processed, and sold, they may include but are not limited to the more common products identified under Table DI - Earth Products, or other inert or commonly useful products used for diverse construction purposes, including, but not limited to: structural fill, concrete products, road construction products; and other products to aid the residential, commercial, industrial customer; and for any other infrastructure use. Explosives - will not be utilized. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page Ii 6.4.5 EXHIBIT E - Reclamation Plan (1) In preparing the Reclamation Plan, the Operator/Applicant should be specific in terms of addressing such items as final grading (including drainage), seeding, fertilizing, revegetation (trees, shrubs, etc.), and topsoiling. Operators/Applicants are encouraged to allow flexibility in their plans by committing themselves to ranges of numbers (e.g., 6"-12" of topsoil) rather than specific figures. (2) The Reclamation Plan shall include provisions for, or satisfactory explanation of, all general requirements for the type of reclamation proposed to be implemented by the Operator/Applicant. Reclamation shall be required on all the affected land. The Reclamation Plans shall include: (a) A description of the type(s) of reclamation the Operator/Applicant proposes to achieve in the reclamation of the affected land, why each was chosen, the amount of acreage accorded to each, and a general discussion of methods of reclamation as related to the mechanics of e ar thmoving; (b) A comparison of the proposed post -mining land use to other land uses in the vicinity and to adopted state and local land use plans and programs. In those instances where the post -mining land use is for industrial, residential, or commercial purposes and such use is not reasonably assured, a plan for revegetation shall be submitted. Appropriate evidence supporting such reasonable assurance shall be submitted; (c) A description of how the Reclamation Plan will be implemented to meet each applicable requirement of Rule 3.1; (d) Where applicable, plans for topsoil segregation, preservation, and replacement; for stabilization, compaction, and grading of spoil; and for revegetation. The revegetation plan shall contain a list of the preferred species of grass, legumes, fortis, shrubs or trees to be planted, the method and rates of seeding and planting, the estimated availability of viable seeds in sufficient quantities of the species proposed to be used, and the proposed time of seeding and planting; (e) A plan or schedule indicating how and when reclamation will be implemented. Such plan or schedule shall not be tied to any specific date but shall be tied to implementation or completion of different stages of the mining operation as described in Rule 6.4.4(1)(e). The plan or schedule shall include: (i) An estimate of the periods of time which will be required for the various stages or phases of reclamation; VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 12 6.4.5 EXHIBIT E - Reclamation Plan (ii) A description of the size and location of each area to be reclaimed during each phase; and (iii) An outline of the sequence in which each stage or phase of reclamation will be carried out. (The schedule need not be separate and distinct from the Reclamation Plan, but may be incorporated therein.) (f) A description of each of the following: (I) Final grading - specify maximum anticipated slope gradient or expected ranges thereof; (ii) Seeding - specify types, mixtures, quantities, and expected time(s) of seeding and planting; (iii) Fertilization - if applicable, specify types, mixtures, quantities and time of application; (iv) Revegetation - specify types of trees, shrubs, etc., quantities, size and location; and (v) Topsoiling - specify anticipated minimum depth or range of depths for those areas where topsoil will be replaced. Acknowledged. Rule 6.4.5(1) is an advisory statement, the particulars of which are provided for, below. MISSION STATEMENT: Utilizing Resource Recovery of Sand and Gravel as a Method of Conservation to Establish DEVELOPED WATER RESOURCES; and to function as a Foundation for the implementation of other beneficial Multiple End -Uses over the Property. Reclamation and Development of the Property over Time. The majority of sand, gravel and other earth product demand, like water, is the consequence of market forces resulting from urbanization. The commercial, industrial, transportation, and other land use matrixes arise to support and sustain a growing residential population. Governments count the roof tops for they rely upon public and commercial revenue to sustain the roads, schools, water supply and infrastructure needed to secure it. With continued growth of human habitat and development in Colorado, the products that make possible the construction and maintenance of it all, comes from the ground. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 13 6.4.5 EXHIBIT E - Reclamation Plan Unconsolidated aggregate deposits simply must be taken where they are formed. The aggregate resource must be recovered from undeveloped locations first, before those locations are overtaken by ever expanding urban development; or it is lost. Now is the time and this is the geologically determined and economically feasible location from which the proposed extraction activity must occur. Hence, the Two Rivers Sand Gravel and Reservoir Project. Underlying earth resources are too often squandered when human development occurs in advance of resource extraction and recovery. Extraction and resource recovery are required by Colorado law to occur in advance of development where sand and gravel deposits are present. The resource is 'recovered' to benefit inevitable and unrelenting human habitat and infrastructure expansion, while providing a more enduring indigenous buffer to the very impacts it serves. The extraction of aggregate resource is in fact resource conservation. Beyond that, it is an essential social asset. Without earth products, transportation maintenance costs increase as infrastructure begins to fall apart. Industries begin to shrink, along with correlated revenues for state and local governments. Impacts would likely spread downstream from there, degrading schools and everything else dependent upon government revenue, as taxes increase to make up the difference. Affected populations would likely begins to flee an ever-increasing tax burden, further depreciating home values while accelerating loss of revenues from ever diminished home valuations, loss of businesses, jobs, and ultimately the very infrastructure itself. Without earth products, the economic engine and quality of life for everyone, begins to unravel. The secondary and enduring benefit of mineral extraction is in the reclamation and restoration of extracted lands. Extraction of aggregate resources is comparatively temporary and transitional by its very nature. Reclamation at this location is geared to lay a foundation that will capture both short and long- term multiple -end use benefits that will complement the dynamic mix of surrounding land uses over time. While residential, commercial, and industrial development will eventually be inspired by economic forces over portions of the Two Rivers property; the primary end use will be the creation of essential Developed Water Resources. An understanding of the vital importance of aggregate resources to the people of Colorado is not new, but well established; and protected. It remains the stated duty of any governing body in Colorado to aid in the lawful recovery of these vital mineral resources under Title 34. Section 22-5-80 of Weld County's Code of Regulations is consistent with Colorado law, both of which require that this resource must be recovered prior to other development which would otherwise impede access to it. Municipalities are obligated for the sake of their citizens to assert the same. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 4 6.4.5 EXHIBIT E - Reclamation Plan The subsequent development of a diverse multiple land use potential at this location, when complemented with sound environmental parameters, as advanced under this application and the attending OMLR permit exhibits, is in keeping with the spirit and intent of the policies and goals of the State of Colorado, Weld County, and the Towns of Evans and Milliken. Approval of the application will allow the resource to be accessed and utilized in a responsible and orderly manner as required under both Colorado law, and consistent with local County and Municipal Regulations. Specific Reclamation Elements and Methods: This application provides substantial detail of features utilizing aerial photography that is ortho-rectified to approximately 1.0± percent of surveyed accuracy. This highly accurate and detailed portrayal of planned extraction and reclamation is visible under Exhibit C-1: Existing Conditions, Exhibit C-2: Extraction Plan Map, and Exhibit F - Reclamation Map. How reclamation will occur over affected lands is further detailed under Exhibit L - Reclamation Costs. As extraction progresses over the Fields south of the Big Thompson River, the resulting 1.25H:1V slopes (2H:1V, where indicated) created during extraction will be concurrently modified when and where practical. Concurrent reclamation is a natural incentive for Operations to speed site recovery while generally serving to lower attending financial warranty burdens. The cut slopes along the extraction limits perimeter will be finished graded by pushing the resulting pit bottom with a dozer until the resulting basin slopes conform with Rule 3.1.5(7). Since the primary end use is Developed Water Resources, the basins are intended to hold waters based upon the rights assigned by decree, or as stipulated in regulatory compliance with the Colorado Division of Water Resources, Office of the State Engineer (OSE). This may include the need to augment water sufficient to cover the anticipated exposed groundwaters of the basins in the unlined state. The entire unlined basin is or will be sufficiently covered under an approved substitute supply plan. In order to again liberate waters set aside for augmentation, the basins will at some point in the life of the activity be lined to segregate the basin from Colorado groundwaters. Lining of basins involves the placement of low permeability compactable fill, from on -site or other suitably sourced geologic materials, into the keyway (dewatering trench'); the same keyway used to facilitate discharge to keep the basins dry and free of groundwaters at the time of extraction. The balance of the basin floors ' Adequacy Item 15: Keyway clarification VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page IS 6.4.5 EXHIBIT E - Reclamation Plan (where needed) and slopes are also covered and compacted with the same materials until it meets the standards established under the August 1999 State Engineer Guidelines for Lining Criteria. Typical to obtaining approval for the constructed liner, the lined basin must pass a 90 -day leak test. Correspondence from the OSE approving the construction of the lined basin will be submitted to the OMLR on receipt; or as part of any request for release of the permit, in part or whole. Essentially, the pushed parent rock material will form the minimum 3h:ly slopes of the basin and be compacted to a permeability of 10 6; forming a lined basin that complies with Colorado Water Law and Guidelines mentioned, above. In this manner, the lined basins will maintain a required separation and accounting of stored water from the underlying ground waters. Evidence of compliance with the rules and regulations of the Colorado Division of Water Resources will be provided to the OMLR on completion of the lined basins. 2 A Backfill Notice is included with this application as an Addendum at the back of Exhibit E - Reclamation Plan, to facilitate the fill of portions of the extracted lands for final end -use potentials beyond water storage, which may include residential, commercial or industrial structures or uses otherwise approved, now or in the future, by Weld County, Colorado; or a Colorado municipality, as applicable. The extent and nature of the water storage basin represents the maximum build -out respective of optimal extraction of commercial product and resulting final slopes. As part of reclamation, lands situated above the anticipated final water level of the completed basins, and within 10.0± feet below the anticipated final water level of the basins, will be graded to 3H:1V, or flatter. Lands below 10.0± feet from the anticipated final water level of the basins will also be graded to 3H:1V, or flatter, unless 2H:1V slopes are otherwise approved by subsequent permit revision. Naturally occurring or previously established slopes may exceed 2H:1V where not otherwise affected by extraction activities and may not be altered as part of reclamation unless necessary to facilitate the reclamation of affected lands. All affected lands between the extraction limits and remaining above the anticipated high-water mark of the basins will be capped with a minimum of six (6.0±) inches of soil, as supported by Exhibit I & J - Soils and Vegetation Information. Timing and use of soil are detailed further under Exhibit I & J - Soils and Vegetation Information and Exhibit L - Reclamation Costs. Where compacted lands exist, and are to be revegetated, those locations will be ripped prior to re - soil application. There are no =c=own areas of compaction at the time of this 2 Adequacy Item 28: Paragraph removed as proposed post mining land use is lined water storage. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 16 6.4.5 EXHIBIT E - Reclamation Plan application which would require such activity; and ripping remains a contingency of the application. The final land configuration will ultimately result in two (2) reservoir basins totaling 234.06± surface acres, with a static water elevation surface area of 217.44± acres (refer to Exhibit F: Reclamation Map). The balance of unoccupied affected lands above the anticipated static water level will be stabilized where necessary utilizing the seed mixture as shown under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. Lands not otherwise occupied for developed water resources will be later developed to the highest possible end -use, and will likely comprise a mixed use which may include other general agricultural uses as well as light residential, commercial or industrial uses. The Primary Revegetation Seed Mixture, combines a thoughtful mingling of predominantly native grasses of diverse height, form, color and function, to assure that the reclaimed site can provide for a multiple -use benefit. Should post resource recovery land development be deferred, or even negated, all affected land remaining above the anticipated final water level of the resulting ponds will be stabilized with a diverse and durable cover of predominantly native grasses. This is compatible with, and an improvement over the diminished lands located in the floodplain of the two rivers, and area monocultures of residential bluegrass lawns and surrounding cropped land. 'Generally, warm and cool seed mixtures can be treated in a myriad of ways. In Table L-1 this distinction is indicated in the column labelled "C/W". Cool season mixtures are often planted in the fall and warm in the spring, however, exceptions may apply. Some argue warm season grasses are better broadcast, while others like them drilled with the cool season grasses. Combined with the creation of waterfowl habitat, the baseline reclamation plan provided for under this submittal will provide less fragmentation of the area ecology than what may otherwise exist or transpire. As such, the operation will result in immediate and enduring positive impacts to area habitat as a long-term beneficial buffer against continued developmental impacts to the river ecosystem. Consistent with previous discussions with conservationists from the Division of Wildlife; operations will result in a desirable establishment of irregularities for the finished reservoirs. For example: The basin irregularities will be provided for, both by direct concurrent grading, 'Adequacy Item 33 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 17 6.4.5 EXHIBIT E - Reclamation Plan post mine landform grading and establishment, and use of fill from excess or residual materials and reject fines from the operations. Shallower locations due to variations in site geology may allow for the creation of other shoreline features through the placement of fill. Due to the unpredictable nature of the anticipated geology [actual depth of material and type will vary - extraction and pond depths are approximated typical maximum extent] and other factors, it is a near misrepresentation to forecast the final appearance of the ponds, as it creates an unrealistic expectation in a regulated environment on the minds of various regulating agents, the general public, and on Operations. Simultaneously, setting false expectations about the final appearance of the ponds, beyond that already portrayed, will drain flexibility from Operations essential to the creation of more desirable effects, while simultaneously exerting pressure for needless and on- going revisions to the permit. It should be remembered that the Annual Report to the OMLR will provide a graphic record of this effort. Since the pace occurs over many years, there is ample time for reflection and analysis of the effort. Time and timing will also come into play respective of materials to be used as fill. The utilization of fill is dependent upon the space available for deposition over completed areas of extraction in relation to the rate of creation of reject fines and or other deposit materials. Other influences will be the attending space for stockpiling, uses, or market conditions for fill material. Some locations will be more advantageous to fill at a given point in time than others, and the attending circumstances cannot be reasonably anticipated. The random nature of this limitation will actually aid in furthering the establishment of preferred non -geometric patterns of the finished ponds. Exhibit F - Reclamation Plan Map, represents the regulated base for which reclamation must be judged as adequate for release. At the very least, the basins delineated under Exhibit F - Reclamation Plan Map, provide desirable shoreline irregularity and slopes in conformance with existing statutory requirements. Anything more is a bonus, for everyone, and every opportunity will be made to take advantage of it, as stated above. Since the creation of aesthetic effects, edge effect, and other natural landforms, remain subjective and empirical, the stated intentions and any resulting efforts to achieve such effects, beyond those identified in the approved seed mixture and as portrayed in Exhibit F - Reclamation Plan Map, is commendable, and to be encouraged. Placement of soil and initial stabilization of affected lands with a stabilizing cover of grasses will better assure a foundation for later vertical development and establishment of cover; whether resulting from natural invasion or direct planning of trees, shrubs, and fortis. By themselves, the grasses will provide a stable foundation for later VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 18 6.4.5 EXHIBIT E - Reclamation Plan enhancements, while visibly improving wildlife habitat by interrupting area monocultures. While end use development beyond that already described cannot be fully determined or detailed at this time, the trend toward continued residential, commercial and industrial development is self- evident on surrounding lands. Although the establishment of native grasses is a primal requirement under this permit, the incorporation of forbs, shrubs and trees remains at the discretion of the landowner. Markets and the inherent values of the landowner to enhance the multiple end use worth of the property will serve to encourage the vertical development and diversity of the area vegetation with the contribution of forbs, shrubs, and trees. The purpose is to add cover, food source for wildlife and pollinators, and stratified creatures that will come to inhabit and depend upon the natural configuration, character and extent of the finished landform and diverse stabilizing cover. It should also be kept in mind that extraction is occurring within an area formerly occupied by monocultural crops, The cottonwoods along the lower terrace of the two rivers will be preserved in the majority. A light culling of a few cottonwoods may occur to assure the integrity of the intended conveyor line and wash basin; or as needed to assure the protection of personnel. The riverine areas will otherwise remain untouched, further complementing the utility of the reclaimed and restored expanse. Whatever long-term development occurs at the location, and on surrounding lands, resource recovery and correlated reclamation at this location will tend to direct human densities away from the two rivers. The reduced densities will produce direct and indirect long-term wildlife benefits and diverse multiple end -use potentials involving inherent wetland development, water resources development, water fowl improvement, and other desirable effects. The long-term worth of this effect will serve to increase the other long-term values for everyone in the area communities formed by the towns of Evans and Milliken; and greater Weld County. The final acreage of land remaining for development relative to surface acres of resulting ponds is illustrated on the following Exhibit F - Reclamation Plan Map. The map details the post resource recovery land form establishment. The size of the resulting basins is a function of area geology and available resource relative to man-made obstructions that serve to prohibit a greater linkage. 4Exhibit F presents Raptor Material's current expectation of the remaining above- ground and underground structures within Affected Area at the point the 4 Adequacy Item 41 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 19 6.4.5 EXHIBIT E - Reclamation Plan reclamation of mining related disturbance is complete. Any revisions, additions, or modifications to this forecast of what may be the outcome of mining and reclamation operations some 30-35± years from now will be updated on required Annual Reports, or by Technical Revision, as warranted, or as otherwise directed consistent with Colorado Statute. The estimated timetable for extraction, commencing approximately spring to winter 2023; is estimated to take 25-30± years combined, or longer, followed by an additional five years to complete reclamation; or a total estimated life of the mine of 30-35± years; ending approximately winter 2053 to 2058. This is a life of the mine operation and all timetables are estimates and may prove shorter or longer than stated. The final determination will occur five years after the deposit is exhausted and all marketable product has been removed and necessary infill completed at the location to the point of final reclamation as approved or modified under the terms of the permit is completed. Table E-1 provides a projection of mine development and regrading/reclamation. The plan as described in Exhibit D and above in this Exhibit E, is a forecast and may vary according to market conditions with mining and subsequent regrading occurring faster or slower, sometimes significantly so. The geology may also dictate changes in the rate of extraction. If efficiency demands in a higher production demand scenario, separate areas could be developed in the manner described in Exhibit D simultaneously. Such changes may happen quickly and would be addressed in the Annual Report. Miscellaneous considerations: Fertilizer may be utilized as part of revegetation efforts. The need for fertilization and any subsequent fertilizer rates will be determined based upon soil tests taken at the time of reapplication of salvaged soil to affected lands remaining above water level. Status of fertilization and soil test results can be included in OMLR Annual Reports, as warranted. Refer to Exhibit I - Soils Information. Weed Control may involve a mix of mechanical or benign vinegar -based sprays as control methods. A detailed plan to control weeds is described in Exhibit I/J. Treatment and control of noxious or nuisance weeds will be reported in OMLR Annual Reports as warranted. A Backfill Notice follows this page. The flexible use of inert fill will facilitate the timely reclamation of affected lands. 5 Adequacy Item 29 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 1 10 6.4.5 EXHIBIT E - Reclamation Plan Table E-1 - Two Rivers Mining -Regrading Schedule Mining -Regrading Schedule Years Schedule 1-5 6-10 11-15 16-20 21-25 26-30 31-35 Area (ac) Area Mined (ac ±) Central Field Center Section 127.1 40.0 40.0 30.0 17.1 North-East Section 23.2 10.0 13.2 West Section 30.5 9.7 20.8 North West Field 53.3 19.2 34.1 Total 234.1 40.0 40.0 40.0 40.0 40.0 34.1 Length (ft) Pit wall Created (ft ±) Central Field 15,074 5,110 3,360 3,360 3,244 North West Field 6,830 4,001 2,829 Total 21,904 5,110 3,360 3,360 3,244 4,001 2,829 0 Length (ft) Pit wall Regraded (ft ±) Central Field 15,074 3,360 3,360 3,360 3,360 1,634 North West Field 6,830 1,040 5,790 Total 21,904 3,360 3,360 3,360 3,360 2,674 5,790 Length (ft) Pit wall Remaining (ft ±) Central Field 15,074 5,110 5,110 5,110 4,994 1,634 0 0 North West Field 6,830 4,001 5,790 0 Total 21,904 5,110 5,110 5,110 4,994 5,635 5,790 0 6 Adequacy Item 29 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I 11 6.4.5 EXHIBIT E - Reclamation Plan BACKFILL NOTICE: Inert fill may be imported, or utilized from existing on -site sources, to meet or exceed planned post extraction land use development potentials over the project area during the life of the operation. The extent and location of fill will be field determined. All inert materials used for backfilling will be consistent with OMLR Rules and Regulations, and those of the Colorado Department of Health and Environment. All backfill material will be placed with sufficient fines to minimize voids and settling of backfilled areas and slopes. There are no known or expected acid forming or toxic producing materials or refuse at this location, nor will materials known to possess such qualities be knowingly utilized for fill. Any other refuse or reject materials that do not meet the definition of inert and requiring removal and disposal will be placed in closed containers and taken to an appropriate landfill for disposal, unless it is otherwise 'inert,' per Rule 3.1.5(9), of the OMLR Rules and Regulations. All materials, whether extracted on -site or imported, will be handled in such a manner so as to prevent any unauthorized release of pollutants to surface or ground water resources. All fill will be integrated to meet or exceed the reclamation plan and correlated end uses authorized under the approved Colorado Office of Mined Land Reclamation permit. All fill above the anticipated static water level of the resulting basins will be soiled and stabilized according to the approved reclamation plan, or as otherwise allowed according to allowed under this application or locally approved land uses. The location and extent of fill utilized over extracted lands will be designated in required OMLR Annual Reports, permit revision, or as part of any request for release of the permitted area, in part or whole. I, Garrett C. Varra, hereby attest that the material to be utilized as inert fill in the area described as the Two Rivers Sand, Gravel and Reservoir Project; is clean and inert as defined in Rule 1.1(20), of the OMLR Rules and Regulations. Garrett C. Varra, General Manager Raptor Materials LLC VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Pagel 6.4.7 EXHIBIT G - Water Information (1) If the operation is not expected to directly affect surface or groundwater systems, a statement of that expectation shall be submitted. (2) If the operation is expected to directly affect surface or groundwater systems, the Operator/Applicant shall: (a) Locate on the map (in Exhibit C) tributary water courses, wells, springs, stock water ponds, reservoirs, and ditches on the affected land and on adjacent lands where such structures may be affected by the proposed mining operations; (b) Identify all known aquifers; and (c) Submit a brief statement or plan showing how water from de -watering operations or from runoff from disturbed areas, piled material and operating surfaces will be managed to protect against pollution of either surface or groundwater (and, where applicable, control pollution in a manner that is consistent with water quality discharge permits), both during and after the operation. (3) The Operator/Applicant shall provide an estimate of the project water requirements including flow rates and annual volumes for the development, mining and reclamation phases of the project. (4) The Operator/Applicant shall indicate the projected amount from each of the sources of water to supply the project water requirements for the mining operation and reclamation. (5) The Operator/Applicant shall affirmatively state that the Operator/Applicant has acquired (or has applied for) a National Pollutant Discharge Elimination System (NPDES) permit from the Water Quality Control Division at the Colorado Department of Health, if necessary. (1) Operations will not adversely affect surface and groundwater systems. 1Measures described in the Two Rivers Application and particularly in this Exhibit G, and also in Exhibits D and E are intended to minimize disturbances to the prevailing hydrologic balance of the affected land and of the surrounding area and to the quantity or quality of water in surface and groundwater systems both during and after the mining operation and during reclamation The manner and method of extraction is detailed under Exhibit D — Extraction Plan. Anticipated effects on surface flows are anticipated to be minor to none. Essentially, the flood plain covers a majority of the property and unless under flood conditions, upland overland flows are generally diverted by levees, surrounding roads, or grassed drainage channels; or otherwise by draining internally into existing or planned basins. a) 2Considerable efforts are made to control storm flows, including the use of grassed waterways. Some rilling will occur on cut slopes, but the sediment is Adequacy Item 43: Minimization of impacts. Adequacy Item 43: Prevention of significant runoff VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I2 6.4.7 EXHIBIT G - Water Information inbound. A minor 6 -inch furrow above cut slopes will create a 1 -foot swale that could minimize such rilling, especially valuable on reclaimed slopes above the final estimated water level of the basins. The stormwater management plan referenced in Exhibit I & J will address broader water management covering the material processing area and any piles of soil or inert fill constructed external to the excavations. b) Impacts to groundwater and area wells from groundwater discharge during mining was evaluated by AWES, LLC in their 27 July 2020 report, as included in this submittal. The report concludes: The results of analytical and numerical solutions indicate that the proposed mine dewatering activities will not adversely affect the regional groundwater hydrology. Based on the location of registered water wells, the saturated aquifer thickness west of the mine is sufficient to provided adequate well yields. The predicted drawdown associated with the mine dewatering represents the worst -case scenario and a substantial amount of time will be required before maximum drawdowns will occur.' 3Additional groundwater evaluation is documented in an August 30, 2022 letter report addressing initial adequacy items and an August 31,2022 revised Dewatering Evaluation from AWES, LLC, both provided as addenda to Exhibit G. The estimated time to reach steady state drawdown due to the mining activity is summarized as follows: `Assuming a saturated thickness of 35 feet, a transmissivity of 4375 ft2/day, an effective porosity of 0.27 and a radius of influence of 4000 feet the time to reach steady state is calculated to be 273 days. However dewatering will be progressive during mining and an estimated 1000 days will be required to achieve this radius of influence during early dewatering operations.' c) 4POST RECLAMATION IMPACTS have been minimized: i. The AWES report of 27 July 2020 evidences that there will be no measurable impacts of either shadowing or mounding of the resulting lined basin. The operation therefore includes lining of the basin during reclamation of the resulting basin. Satisfaction of Colorado State Standards as to the integrity and functionality of the resulting lined basin will be made in cooperation with the Colorado Division of Water Resources, and any resulting submittals and approvals made available to Supplemental Groundwater Adequacy Item 13 Adequacy Item 28: Various edits in this section clarifying post mining land use as lined reservoir VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I3 6.4.7 EXHIBIT G - Water Information the OMLR at the time of the Annual Report, or by separate cover. No measurable impacts to the prevailing hydrologic balance are foreseen. ii. The Flow Technologies Report of 22 January 2020, provides a plan of modified basin design to be incorporated into this submittal as a means to minimize erosion of the basin berms while optimizing the integrity of the basin from the South Platte and Big Thompson Rivers during a 100 -year flood event. (2) (a) Please refer to Exhibit C-1: Existing Conditions Map. 5Wells are also shown on Exhibit G: Water Information Map and a table providing well details is included as an addendum to this Exhibit G. (b) The known aquifer under the site is the stream alluvium. (c) Discharge water will be dissipated with hard surface riprap or established grassed waterways. Other waters are retained by internal pit drainage, directed by vegetated berms or established waterways or through the maintenance or establishment of a stabilizing cover of vegetation, or as otherwise established under an approved Colorado Department of Health stormwater permit and/or stormwater discharge permit. 6Stockpiling of soil, overburden, or product above the existing ground elevation will not occur in a manner understood to obstruct flood waters where they might occur within the existing floodplain. It is understood and agreed here -in that their longitudinal dimensions if they occur there should extend parallel to anticipated flood flows where they exceed a cone or other shape that might find its existence contrary to intent by volume beyond that which could be understood to be temporary, or transitory; especially outside of seasonality where flooding might be more reasonably anticipated. As stated in Exhibit D, the conveyor will be set on an elevated structure at varying heights to be situated about the 1 in 100 -year flood level. An average height of 7 feet is expected. The conveyor will be supported by legs at intervals of approximately 20 feet with typically 6- x 2- x 2 -foot concrete blocks sitting on ground surface used as necessary to anchor the legs. The conveyor will span the river channel and metal (or other appropriate material) pans will be installed under the conveyor structure to prevent spillage into the river. The design will be similar to other Raptor locations where an extended span has been required to cross a county road. Final conveyor specifications are to be determined however belt width is anticipated in the range 24-36". Supplemental Groundwater Adequacy Item 4 6 Adequacy Item 45: Floodplain management. including conveyor crossing discussion VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I4 6.4.7 EXHIBIT G - Water Information 'Included as an addendum is the Headwaters Corporation report (July 2019) for what is generally referred to as the Westervelt project which was a stream and floodplain restoration project downstream and adjacent to the Two Rivers project at the confluence of the South Platte and Big Thomson rivers. As described in Exhibit I -J, approximately 200,000± cu.yd. of material excavated in the execution of this project was stockpiled in a 28± acre area comprising most of the North- East section of the Central Field. The Headwaters report discusses the excavation and placement of this material and expected hydrological impacts. 8A groundwater monitoring plan has been prepared for the Two Rivers project and is attached as an addendum to this Exhibit G. (3) The three components of the project water requirements are water removed for dust control, water removed with the product, and evaporation from exposed ground water. Dust will be controlled using truck sprinklers, and the estimated frequency is one to ten loads per day depending upon field conditions. Dust will be controlled using truck sprinklers, and the estimated frequency varies daily according to seasonal influences of rain, snow, freezing, and temperatures (Refer to Seasonal Temperatures and Precipitation. At 3,000 gallons of truck capacity, the annual demand is 10.6 acre-feet. (Refer to following Chart (days of hot, freezing, rainy and snowy days derived from; https://www.bestplaces.net/weather/county/colorado/weld): * not including Sundays Holidays . 3,000 gallons Truck per Dust Suppression Month Active Days* Hot Freezing Rainy Snowy # Days # Trucks Total Trucks # gallons total gallons Total Acre Feet Days Days Days Days per day per month per Month per year January 25 0 3`i 4 39 18 1 18 54,000 0.16 February 23 0 2 4 34 16 1 16 48,000 0.15 March April 28 26 0 0 6 8 36 24 17 16 2 3 34 48 102,000 144,000 0.31 0.44 May 25 1 10 0 9 14 5 70 210,000 0.64 June 26 7 0 9 0 2 24 10 240 720,000 2.21 July 25 1(-3 0 7 0 -9 25 10 250 750,000 2.3 August 27 12 0 8 0 -4 27 10 270 810,000 2.48 September 25 7 0 4 21 5 105 315,000 0.97 October November 25 23 0 0 5 5 19 34 19 15 3 2 57 30 171,000 0.52 90,000 0.28 December 25 0 4 38 18 1 18 54,000 0.16 303 40 77 226 230 1156 Annually 3,468,000 10.6 Acre Feet 1040 Trucks Apr.- Oct = 3,120,000 90%or 9.6 Acre Feet Adequacy Item 45: Headwaters addendum explanation Adequacy Item 46 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 5 6.4.7 EXHIBIT G - Water Information After the water table is encountered, the water removed with the estimated 1,200,000 tons of product is 35.32 acre-feet per year. The estimated net evaporation is 2.64 feet per year. At the maximum potentially exposed ground water of 217.44± acres, the annual evaporation is 574.25± acre-feet. The monthly distribution of these estimates is shown in the following table. The reclamation plan provides that the pits will9 be lined after being mined. The lined pits will not require replacement water and will be used for storage. There may be incidental demand for water to establish vegetation on the site after lining is completed. However, the ultimate demand for water will be zero. MONTH PRODUCT GAL. WATER/TON) (9.59 DUST CONTROL NET EVAPOATION Tons af Trucks af ac x %ev af November 60,000 1.77 30 0.28 217.44 0.104 22.61 December 54,000 1.59 18 0.16 j 217.44 0.000 0.00 January 54,000 1.59 18 0.16 j 217.44 0.000 0.00 February 93,000 2.73 16 0.15 j 217.44 0.113 24.57 March 127,500 3.75 34_-_-_ 0.311217_44 0.138 i-_30.01 April 138,000 4.06 48 0.44 j 217.44 0.221 48.05 May 139,500 4.11 70 0.64 j 217.44 0.288 62.62 June 135,000 3.97 240 2.21 j 217.44 0.413 89.80 July 127,500 3.75 250 2.30 j 217.44 0.453 98.50 August 118,500 3.49 270 2.48 217.44 0.418 90.89 September 93,000 2.73 105 0.97 217.44 0.294 63.93 October 60,000 1.77 57 0.52 217.44 0.199 43.27 Apr -Oct 811,500 23.88 1040 9.561 a 497.06 TOTAL 1,200,000 35.32 1156 10.62 574.25 (4) Water available for supply are from Six sources: Beeline, Big Thompson, South Platte Ditch, Hayseed Ditch as decreed in Case No. 90CW174, four shares of the Rural Ditch Company as decreed in Case No. 03CW306, five shares of Last Chance Ditch Company, 25.0 shares of Godding Ditch Company, and water decreed in Case No. 01CW274. From April through October, water use at the site will be replaced to the stream system using the historical consumptive use credits from any of the sources and/or from storage. 9 Adequacy Item 28 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I6 6.4.7 EXHIBIT G - Water Information Because storage is available to regulate the supplies, only the annual historical consumptive use for the sources is shown in the following table. Source Annual Consumptive Use, a -f Beeline 87 Big Thompson & South Platte 274 123 Hayseed Rural 434 Last Chance 1,191 Godding 384 Total = 2,493 The storage sites are lined pits described in Case No. 01CW274 decree. Water available under these storage decrees will also be stored and used for VCI operations. The storage facilities are listed in the following table. Those currently lined and approved by the state are 112, Von Ohlen, and Dakolios. VCI STORAGE FACILITIES (All Values in Acre -Feet) Reservoir Active Capacity, a -f Dead Storage, a -f i 112 1,552 0 Dakolios 1,104 0 Von Ohlen 1,300 0 Kurtz 4,000 0 YEAR NOT 7,500 3,000 EXCEED A -F refill PER of a -f 0 TO plus Total (5) 10A Colorado Wastewater Discharge Permit System Permit has been applied for with the Colorado Department of Health, and an approved permit issued September 27, 2022. The application and permit are provided as an addendum to this Exhibit. Dewatering activities are discussed in Exhibit D. 1 ° Adequacy Item 44 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 7 6.4.7 EXHIBIT G - Water Information (6) The application provides for the lining of the extracted basins (please refer to the AWES Dewatering Evaluation Report of 27 July 2020. Lining will involve the utilization of suitably derived on -site materials to meet final 3H:1V slopes. Subsequently, the same materials may be compacted to satisfy standards for lined basins as established and governed by the Colorado Department of Water Resources Office of the State Engineer. Once operations near completion of any lined basin, the OSE will be contacted and the lined basins will be approved by the OSE prior to use. The OSE approval letter will be provided to the OMLR as a condition of the permit as evidence that the lined basin has met the specifications necessary to pass a liner test as part of the OSE approval process. Consistent with conclusion in the AWES Report, lining of the completed basins will have 'will have a de-minimis is effect on groundwater hydrology. The report continues, adding that, `Predicted post lining head levels immediately up and downgradient of the barrier walls are within the range of normal seasonal water table elevation changes.' NOTE: Information showing baseline piezometer well readings and respective locations immediately follow this page. 11The table has been updated from the original application with data extended through June 2022, and the well names conformed to those on Exhibit C-1: Existing Conditions Map and Exhibit G: Water Information Map. 1' Adequacy — Dewatering Review Item 3 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page Ii 6.4.5 EXHIBIT I/J - Soils and Vegetation Information 6.4.9 EXHIBIT I - Soils Information (1) In consultation with the Soil Conservation Service or other qualified person, the Operator/Applicant shall indicate on a map (in Exhibit C) or by a statement, the general type, thickness and distribution of soil over the affected land. Such description will address suitability of topsoil (or other material) for establishment and maintenance of plant growth. The above information shall satisfy "completeness" requirements for purposes of determination of date of filing. (2) If necessary, at its discretion, the Board may require additional information on soils or other growth media to be stockpiled and used in revegetation to be submitted subsequent to the filing and notification of "completeness" of the application. 6.4.10 EXHIBIT J - Vegetation Information (1) The Operator/Applicant shall include in this Exhibit a narrative of the following items: (a) descriptions of present vegetation types, which include quantitative estimates of cover and height for the principal species in each life -form represented (i.e., trees, tall shrubs, low shrubs, grasses, forbs); (b) the relationship of present vegetation types to soil types, or alternatively, the information may be presented on a map; and (c) estimates of average annual production for hay meadows and croplands, and carrying capacity for range lands on or in the vicinity of the affected land, if the choice of reclamation is for range or agriculture. (2) The Operator/Applicant shall show the relation of the types of vegetation to existing topography on a map in Exhibit C. In providing such information, the Operator/Applicant may want to contact the local Soil Conservation District. Exhibit I & J — Soils & Vegetation Map, identifies the type and extent of soils over the project site and surrounding lands. Areas designated for resource recovery within the extraction limits will remove all recoverable soils. A portion of the available soils will be utilized for reclamation from a portion of either existing or future soil stockpiles, or suitable in situ soils, as circumstances warrant. The balance of soils not otherwise needed for reclamation of affected lands remaining above the anticipated static water level of the completed basins will be made available to meet the demands of the market. I nterpretation of current soil conditions and vegetation suitable for reclamation relies in part on information and correlated available data from the U.S. Soil Conservation Service (SCS) Soil Surveys and updated digital information of the same by the renamed U.S. Natural Resources VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 12 6.4.5 EXHIBIT I/J - Soils and Vegetation Information Conservation Service (NRCS). Range Site Descriptions (uniquely designated for each Soil Unit as shown by number and boundary on Exhibit I/J: Soils and Vegetation Map) and other related soil and ecosystem information taken from these publications. The information extracted from this source is included at the back of this exhibit. SOIL LEGEND of on -site soils (Refer to Exhibit I/J: Soils & Vegetation Map): SOI L UNIT #3. AQUOLLS & AQUENTS, GRAVELLY SUBSTRATUM; CAPABILITY SUBCLASS VI w; SALT MEADOW RANGE SITE DESCRI PTI ON [A Horizon = 0-48" Depth - Atypical - Will vary randomly - poorly formed in alluvial floodplain] SOIL UNIT #4. AQUOLLS & AQUEPTS, flooded bottoms and depressions 0% SLOPES; NO CAPABI LI TY SUBCLASS; AQUOLLS in SALT MEADOW & AQUEPTS in WET MEADOW RANGE SITE DESCRI PTI ON [A Horizon = 0-60" Depth - Atypical - Will vary randomly - poorly formed in alluvial floodplain] SOIL UNIT #51. 0TERO SANDY LOAM, 1-3% SLOPE; CAPABILITY SUBCLASS I I I e I RRI GATED & VI e NON -I RRI GATED; SANDY PLAINS RANGE SITE DESCRI PTI ON [A Horizon = 0-12" Depth] SOI L UNIT #52. 0TERO SANDY LOAM, 3-5% SLOPE; CAPABI LI TY SUBCLASS I I I e I RRI GATED & VI e NON -I RRI GATED; SANDY PLAINS RANGE SITE DESCRI PTI ON [A Horizon = 0-12" Depth] SOI L UNIT #53. OTERO SANDY LOAM, 5-9% SLOPE; CAPABILITY SUBCLASS I Ve I RRI GATED & VI e NON -I RRI GATED; SANDY PLAINS RANGE SITE DESCRI PTI ON [A Horizon = 0-12" Depth] I nterpretations of former native conditions of soils and vegetation are offset and updated by present day field investigations, aerial images, and other resources. Ultimately, what is applied relies upon an arena of experience that draws upon an empirical understanding of the web of environmental, technical, economic, industrial and regulatory factors acting in concert with historical land use influences that depart from the SCS/NRCS records reflected in the Soil Legend, above; and as shown on Exhibit I /J: Soils and Vegetation Map. The combined effort eventually finds itself as applied and established over the completed and newly adapted landscape of the future; as projected in the diverse exhibits made part of this application. The attending narrative descriptions in the included Soil Survey addendums and extracts, detail the native soils, vegetations, and associated ecological conditions likely prevalent over unaltered lands of like kind, and as they might present themselves over the identified parcels. The identified vegetation is an indicator of what did, or may, grow on the represented soils under native undisturbed soil conditions. This information is utilized to create the seed mixture(s) proposed under Exhibit L - Table L-1: Primary/Preferred Revegetation Seed Mixture. The species selected for reseeding are selected as offering the best genetic potential for establishment of a diverse and enduring stabilizing cover in the reclamation and restoration of the affected lands. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 13 6.4.5 EXHIBIT I/J - Soils and Vegetation Information A portion of in situ soils may be used in an over the shoulder method to resoil the completed banks of basin slopes or other upland areas in time. Commonly, soils will be parked in stockpiles u ntil ready for application in a manner more fully described below. Consistent with existing zoned agricultural practices, soil from an adjacent wetland bank was approved by the City of Evans, and completed in early 2021. The City of Evans approved (refer to the Addendum at the back of this Exhibit) the placement of these soils within the floodplain of the u pper North-East portion of Central Field, as shown on Exhibit C-2: Extraction Plan Map. These orphan soils are in place, seeded, and the area remains under continuing agricultural production, yet are no longer part of the area floodplain. The current extent of this 200,000± cu.yd. stockpile is represented on Exhibit L: Financial Warranty Map. This stockpile location area will also receive a portion of soils removed from planned extraction locations over other areas of Central and North-West Fields. It should be noted that a monoculture of cultivated corn occupies a majority of the planned areas of extraction, and will gradually be turned out of production through extraction. This soil may be utilized to line the resulting basins, for reclamation of affected lands above the static water level, or for market as warranted. 1As described in Exhibit D, wetland conditions appear confined within portions of the stream terrace and bank -full stage of the rivers, and along segments internal to the Evans Canal. Excavation and processing activities will not take place within these areas. Under Exhibit M is an approved U.S. Army Corps of Engineers report designating 'No Permit Required.' If and when a conveyor is built upon the projected line, the footings are not expected to exceed the requirements for a Nationwide Permit, but if they will, a Nationwide Permit will be applied for and secured prior to affecting such areas. If a Nationwide Permit is necessary, the OMLR will be provided with the necessary justification or approval under an OMLR Technical Revision to that e nd. At this time there is little to find in dominant preferred species of cover typifying the cropped fields o r riverine areas. Beyond the row crops, the former pasturelands appear impacted by overgrazing, monocultures of smooth brome, annuals, and other comparatively recent impacts. Reclamation will not return the former Fields to agricultural crop production. Further, present day impacts over the planned Processing and Wash Pond locations do not reflect representative or realistic percent cover of a desirable matrix of native vegetation communities intended for reclamation. Consequently, the reclamation target will be to establish a stabilizing foliar cover of predominantly n ative vegetation (refer to seed mixture) of approximately 20 percent [determined as measured at the stem three inches above the ground surface respective of the foliar diameter of the established grass species, as determined by ocular estimates, or utilizing standard vegetation cover analysis such as line transect, as warranted] . For clarity, topsoil is generally regarded as the plow layer (upper six inches) on agricultural soils, o r the A-1 soil profile horizon otherwise. The solum, or soil, includes the topsoil plus all other material found above the regolith of the parent rock, and generally no deeper than the optimal ' Adequacy Item 49 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 14 6.4.5 EXHIBIT I/J - Soils and Vegetation Information depth of roots of perennial plants and trees, or which otherwise meets the definition of soil. One soil differs from another soil by its unique properties and characteristics (such as horizon profile development, structure, texture, color, percent organic matter, chemical composition, etc.) and is identified as such by soil scientists, and detailed in available SCS (NRCS) Soil Survey documents. The affected soils to be extracted as permitted are designated under the soil survey to fall predominantly under Unit 3: Aquolls and Aquents, gravelly substratum; and may include minor components of Unit 10: Blankard sandy loam (refer to extracts and tables from the 1980 Weld County Soil Survey — Southern Part). Occurring in flood plain locations, as they do at this location, while described as `deep,' would apply more commonly to the Mollisols that appear to form a minor component of the area soils, while the majority of the location is more characteristic of Aquolls, Aquent or Entisol soil formations, which are commonly poorly formed soils in floodplain locations, and lacking a typical profile or horizon development; or, in the case of the Blankard Series, having a shallow A -profile of 0-5 inches in depth overlying sand and gravel. The lack of a deep, well developed soil profile is in part due to alluvial flooding which both scours and lays down sediment of diverse textural classes over time, but which lacks the appearance of an I nceptisol which is also commonly associated with flood plain locations. Deeper profiles may occur, however they are difficult to map under the best of conditions as they may vary every three (3) feet. Fundamentally, previous crop production activities over Unit 3 soils created a plow layer over the majority of Central Field, to an approximate depth of six inches; and likely contains the greater percentage of desirable organic matter and texture amenable to plant establishment and sustainability. These former rangelands turned to croplands have no predictable soil profile of consequence as you progress increasingly below the cropped layer. Other minor areas of impact over the remaining acres found within the parcel, have poorly developed soils whose depths vary from zero to eight inches. While anomalous pockets of deeper soil depths may occur, for purposes of this submittal, we will assume a soil depth to the plow layer of six inches over affected lands, excluding any obvious previously disturbed ground where soil has been removed (trenches, structures, etc.). Regardless, there is sufficient soil to assure a resoil depth of approximately six inches over the basin banks above the anticipated static water level of the reservoirs. The predominantly Otero Series soils underlying planned processing and product stockpile and transportation north of the Evans Canal are shallow soils of a foot or less over eolian deposits and alluvium; or sandstone bedrock, as in the case for the Tassel Series Soils. These soils are best left undisturbed where possible and simply reclaimed in place once processing and related activities are completed. For purposes of this submittal, all lands within the indicated permit boundary will be considered affected lands, but only those locations between the existing access roads, and which otherwise remain above the anticipated static water level of the resulting basins, will be soiled and seeded to establish vegetation consistent with the approved reclamation plan. All other previously disturbed lands outside of this area may be seeded to establish the desired vegetative cover where reaffected by planned activities, but in its previously disturbed state will not receive additional soil resources beyond what already remains, if any. Fortunately, the act of extraction serves to return affected lands to a stable configuration, and in a manner that creates a more enduring and beneficial habitat of indigenous vegetation and abundant water. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page IS 6.4.5 EXHIBIT I/J - Soils and Vegetation Information Soil salvage will commence with the removal of the surface layer of soil to a mean depth of 6.0+ inches, depending upon equipment and equipment operator limitations. Additional depths of soil (to the extent it occurs) will be removed in like manner until commercially viable overburden and aggregate are reached, unless already exposed as a result of poor soil development or flood based deposition. Soil salvage will be conducted primarily with excavators, but may include other heavy equipment such as bulldozers as warranted. To minimize the undesirable effects of soil blowing and loss, and to avoid damage to the soil resource via compaction, soil will be stripped wherever possible when soil is moist, and not dry or wet. Any portion of the solum suitable for plant regrowth will be utilized to meet the minimum depth of soil replacement for reclamation, with the excess made commercially available for export from the property. Generally, soil will be retained in sufficient volume to reclaim all lands remaining between the anticipated static water level of the basins and existing access roads which surround them at any given point in time during resource recovery operations. As detailed under Exhibit L - Reclamation Costs, the initial exposure of lands requiring revegetation will be approximately 6.15± acres, requiring 4,961± cu.yds of soil. Total replacement volume required for Central and North- West Fields combined is 16.52± cu.yds of soil. Once removed from its native location, soil retained for reclamation will be stockpiled over the North-East portion of Central Field, in an area already improved above the prior floodplain; or otherwise windrowed along the perimeter of the basin area of extraction or area to be resoiled and seeded with the reclamation seed mixture specified under Exhibit L - Table L-1: Primary/ Preferred Revegetation Seed Mixture, or as otherwise determined under an approved revision. Stabilization of inactive soil stockpiles will provide an opportunity to gauge the performance of the seed mixture while attempting to provide a stabilizing cover of vegetation over the stockpiled soil until it is ready for replacement on finished slopes and affected lands remaining above the anticipated static water level of the completed reservoir basins. Direct precipitation from short duration high intensity rainstorm events, and wind, are the common erosion forces opposed to soil stability over in situ or established perimeter basin slopes at this location. The more uncommon flood event is considered under Exhibit G: Water Information, in the included Flow Technologies, Flood Control Mitigation Plan of 22 January 2020. Never the less, with few exceptions, the natural forces are commonly slight since the location geology and agricultural uses form a nearly flat table beyond the slopes of the extracted basins. Further, extraction will result in basin slopes that cause water from direct precipitation to drain internally, minimizing concentrated flows to existing area drainageways outside of the basin areas; while acting as detention and temporarily lowering any intersecting flood velocity and peak flows during a flood event. Additional conservation measures will be taken for common storm events to assure site stability and protection of off -site areas. An example would be directing overland flows, beyond the influence of the extracted basins, to existing or established grassed water ways. The operator's stormwater management plan may address additional detailed information about maintaining on -site stability consistent with its pending Colorado Department of Health stormwater permit. The measures taken to stabilize soil stockpiles described above, should be adequate for controlling erosion from wind and direct precipitation at those locations. Wind born effects are reduced by VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 16 6.4.5 EXHIBIT I/J - Soils and Vegetation Information surface roughing during continued development of agricultural row crops, or from the natural consequence of extraction activity, itself. Due to the flat topography of the parcel, the interception of upland overland flows by local irrigation ditches and surrounding roads, there is little upland watershed that would impact these locations as a result of nominal storm related events. The greater threat of erosion will be to resoiled slopes pending establishment of vegetation during reclamation. While some sheet and rill erosion can be anticipated on unprotected areas following seed bed preparation and seeding, planned conservation measures should help to limit erosion potential that would threaten the revegetation efforts. Prior to resoiling, the foundation material that will underlie the soil will be sculpted to establish initial soil stabilization features, and left rough to aid in resoil adherence. Soil will be placed over a 12-18± inch minimum friable, or otherwise unconsolidated, subsoil. A 12-18± inch swale with slopes of 3H:1V or flatter will be placed above finished slopes where necessary to direct any u pland surface flows around the finished slopes to an established stable drainage corridor or grass -way. Resoiled areas will be allowed sufficient time to settle prior to seeding. Seeding will commonly follow in the fall or spring as detailed under Exhibit E — Reclamation Plan. Resoiling will occur when soil moisture is adequate to prevent blowing, yet dry enough to prevent compaction. Part of the soil rebuilding process on the reconstituted soils will be in establishing structure to the soils to facilitate plant -soil -water relationships. Overly compacted soils will tend to limit soil structure development and create a poor seedbed for later establishment, so revegetation may be deferred if soils to be reclaimed are manipulated while wet, instead of moist. Once applied to the surface, the new soils will be exposed to the raw forces of erosion until adequate vegetative cover and root mass develops. Erosion requires both detachment and transportation in order to occur. Running water, wind, and raindrop impact are the main forces of e rosion acting upon the soil. The use of a sterile hybrid live cover crop will aid in the stabilization of the soil by allowing a quick vegetative cover to become established in advance of the native grasses. The hybrid will also serve as an aid to reduce competition resulting from the establishment and growth of unwanted pioneer species (weeds) on disturbed ground. The attending reclamation seed mixture, and as approved, has a provision for the use of a sterile hybrid grass in lieu of mulch. Mulch, even when crimped with specialized equipment, is subject to being blown off the property, or reduced to an ineffective stubble. Often, it has been observed to intercept rainfall where it quickly evaporates from the stubble surface, limiting the benefits of light precipitation by preventing infiltration and percolation of moisture to the root zone. The hybrid on the other hand will establish quickly, but since it is sterile, will not continue to compete with the e merging native grasses. After two to three years, the hybrid grass will begin to die out just as the native grasses emerge and improve their dominance over the revegetated areas. I ncreasing Organic matter, such as the incorporation of manure into fallow soils, will aid in the restructuring of the new soils by increasing the moisture and fertility holding capacity of the upper VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 17 6.4.5 EXHIBIT I/J - Soils and Vegetation Information profile seed bed, while simultaneously facilitating healthier plant -soil -water relations and overall root development of the emerging grasses. As the roots of the emerging grasses develop and mature over time, the resulting root mass will serve to build upon the base percent organic matter content of the new soils, thereby increasing the potential for long term survival and spread of the established grasses. Soil testing may occur on the new soils to better gauge the need or success of any applied organic soil amendments respective of the resulting vegetative cover. The addition of fertilizer may also aid in the establishment, growth and survival of the emerging grasses. Fertilizer may be applied to the seeded areas at rates determined from soil tests of the reapplied soils. To this end, soils may be sampled as needed. Sampling will utilize a hand auger and approved NRCS soil sample bags, and utilizing recommended procedures. Any soil testing will be conducted by the CSU Soil Laboratory in Ft. Collins, Colorado. The tests will be used to monitor soil quality and suitability of any amendments. Fertilizer may be withheld until after emergence to deter the encouragement of weed species. The use, composition and rates of fertilization will be determined prior to the time of seeding where appropriate, and may be reported in the OMLR Annual Reports, as appropriate. WEED MANAGEMENT PLAN: Mapping and Identification: Field identification and location of targeted weed species is fundamental to determining the extent and character of weed infestation; and in the subsequent development of a treatment plan. Due to the complex nature of identification, assistance with identification and mapping will be sought from among Weld County Weed and Pest Division; Colorado State University Cooperative Extension Service; U.S. Natural Resources and Conservation Service; as well as on-line and internal resources. Mapping will attempt to identify general areas of infestation within the permit boundary, and vectors of infestation from inside or outside the permit boundary. Vectors are a consideration in prevention of future infestation, which may affect on -site behaviors, including method and means of access within permitted lands. An expectation that vectors from adjacent lands must be treated by adjacent landowners if treatment on permitted lands is to be fruitful is part of continuing treatment considerations. Since the list of noxious weed continues to grow; and considering the development of new treatments; this management plan is intended to retain the flexibility needed to meet future conditions and capabilities in the arena of weed management and control. 2Weed management will be under the supervision of a certified weed management specialist. All applicable requirements currently in force at the time will be adhered to. The primary species to be identified, mapped (if found), and treated will include those species on the State of Colorado noxious weed list, as updated. List A species will be eradicated and List B Species will be 2 Adequacy Item 34/50 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 18 6.4.5 EXHIBIT I/J - Soils and Vegetation Information controlled. Weed management efforts will also attend to current guidance from the Weld County Department of Public Works. It should be noted that many weeds are sourced and vectored from adjacent lands and waterways. Weed management will suffer to diminishing effects that may beyond the capacities of the Operator to ameliorate if responsible weed management fails on those lands. Consideration of due diligence should apply respective of on -site efforts and limitations due to sources and vectors beyond the reach of the Operator. Treatment: Once the nature and extent of weeds have been mapped, and vectors identified; a course of treatment options will be considered in order of priority of economy and effectiveness. The overall o bject of weed management will be to control weeds by establishing a healthy competitive stand of vegetation that wins the competition for plant available water. This effort is linked to on -site soil management; including monitoring of soil fertility and percent organic matter on problem lands; relative to distribution and amount of field available moisture on affected areas. Physical weed control at the site will utilize non -chemical means, unless, due to weed morphology, o r other factors, circumstance require application of other methods or an approved herbicide. If chemical weed control is utilized, it will be conducted in compliance with manufacturer's recommendations and in conformance with applicable federal, state, or local laws. Chemical treatment of weeds will be the last option considered except where all other methods of competitive control fails; including mechanical cutting, tilling, or removal of noxious weeds. Where possible, pre -emergent weed control chemicals will be utilized. An exception to chemical weed control would be operator applied concentrated vinegar based organic weed control that does not harm soil or water. This is especially advantageous in application near water bodies. I n general, weeds will be mowed or mechanically removed before a seed head can develop. This will take priority over recently seeded areas expressing emergent grasses. Where mechanical means fail; chemical applications may follow according to recommendations from previously stated sources, and applied accordingly (see above) to prevent damage to grasses, aquatic species and wildlife. An example of Chemical treatment and primary noxious weeds can be found at the Colorado State University Extension Service website: http://www.ext.colostate.edui. Still, predominant weed control efforts will focus upon prevention, principally through the establishment of a diverse stabilizing cover of grasses, as described earlier. Regardless of control methodology, the intent of mechanical and chemical methods will be to prevent weed species from reproducing vegetatively, or by seed in percentages that threaten the preferred species. I n general, the idea is to aid the grasses in out competing weed species for plant available water and n utrients in the new soils, until such a time that the grasses are fully established over the applied areas, are dominant over the weeds, and capable of self -regeneration. It should be understood that some weeds will remain. Total eradication of weeds is unlikely under the best circumstances, and is not a reasonable expectation or likely outcome. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page ll 6.4.12 EXHIBIT L - Reclamation Costs (1) All information necessary to calculate the costs of reclamation must be submitted and broken down into the various major phases of reclamation. The information provided by the Operator/Applicant must be sufficient to calculate the cost of reclamation that would be incurred by the state. (2) The Office may request the Operator/Applicant to provide additional, reasonable data to substantiate said Operator/Applicant's estimate of the cost of reclamation for all Affected Lands. Summary of Reclamation Costs: $ 14,377.10+ $ 116,583.70± $ 380,970.34± $ 20,633.30± $ 5,449.27± $ 74,552.68± $ 612,566.39± $ 10,000.00+ Site Discharge Total Grading per Extraction Front. Total Liner Construction Expense Total Re -soiling (inc. Processing area) Total Re -vegetation Expense (inc. Processing area) Total Processing/Conveyor Removal Expense Sub -Total Possible Mobilization and Demobilization Costs (pending OMLR $ 622,566.39± $ 151,501.53+ estimate) Sub -Total Direct Costs Possible Indirect Costs Pending DRMS Indirect Costs @ 24.335 % $ 774,067.93+ of Total Reclamation Costs Grand Total - Financial Warranty Amount - Pending OMLR Review and estimates including estimated expenses for State of Colorado Mobilization and Demobilization and other `Indirect' cost determinations by the Office. Continued... next page... VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I2 6.4.12 EXHIBIT L - Reclamation Costs SUMMARY OVERVIEW: Table 1 - Primary Data on Area of Total Proposed Affected Lands and Reclaimed Features: Entity Central Field North-West Field Combined Extraction — finished basin (Acres) 180.76± 53.30± 234.06± Static Water Area — surface (Acres) 168.94± 48.50+ 217.44± Static Water Area — elevation (ft.) 4673 4675 Basin Level ( Lands Above ) Static Water 11.82± 4.70± 16.52± Basin Area Volume (cu.yds.) 9,987,145.79± 2,405,314.58± 12,393,460.37± Static Water Level Volume (Gallons) 2,017, 144,043.20± 485,811,069.46± 2,502,955,112.66± Static Water Level Volume (Acre Feet) 6,190.39± 1,490.90± 7,681.83± Plant Processing Area (Acres) 15.76± Wash Pond Area (Acres) 5.60± Total Level Lands (Acres) Above Static Water 37.98± NOTE Well: All lands within the 409.234± acre permit area are considered as affected lands under C.R.S. 34-32.5-103(1) respective of this permit application and any subsequent permit revisions or amendments to the permit as originally approved. Previously affected ground prior to on -set of Operations under this permit will not be reclaimed under the terms of this permit unless otherwise re -affected beyond their original state. Public Lands and other easements and Right -of -Ways are offset from operations and while they may fall within the 409.234± acre parcel — are excepted from the permit conditions to the extent of their approved setbacks. The following estimates utilize assumptions based upon the pre -disturbed state of the application for purposes of determining estimated costs of reclamation and correlated financial warranty. Where appropriate, information is generalized and approximated from similar estimates determined by the Colorado Office of Mined Land Reclamation (OMLR), as indicated: RECLAMATI ON EXPOSURE: Based upon the Extraction and Reclamation Plans of this application, the status and trend of activities and affected land; and related calculations to estimate reclamation liability, are determined as follows. Please Note: Due to the difficulty of calculating heavy equipment costs similar to the Division's software program, unit costs from previous and reasonably current Division estimates of like or similar kind have been utilized to create a reasonably close estimate. The per unit basis from Division records are shown along with other sources used or referenced to determine unit costs, at the back of this exhibit. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I3 6.4.12 EXHIBIT L - Reclamation Costs METHOD OF EXTRACTION: Before concurrent grading, resoiling, and revegetation for reclamation can commence, a perimeter keyway (dewatering trench1) must first circumnavigate the area where the perimeter slopes form along the extraction limits. For Two Rivers, this includes four sequential areas of extraction: • 127.10± Acres - Central Field — Center Section • 23.19± Acres - Central Field — North-East Section • 30.47± Acres - Central Field - West Section • 53.30± Acres - North-West Field Exhibit L: Financial Warranty Map, shows Initial Extraction will begin in the yellow hatch area shown on the Exhibit L Map, comprising 16.26±. The direction of extraction will follow the perimeter of the extraction limits over approximately 75.45± acres in order to establish the perimeter keyway for the 127.10± acre Center Section of Central Field. The perimeter extraction will leave a 51.65± acre Core, that may be extracted as needed as keyway drainage capacity allows. The initial extraction area is bordered to the South along a near 800± foot section of oil and gas line that is pending removal; along with the two oil and gas wells, also pending removal (refer to Exhibit C for ownership details). Extraction will not occur within 10 feet of these lines, or 25 feet from the wells, as indicated in the setbacks detailed under Exhibit D: Extraction Plan. Below this gas line is an existing pond and well that will be used as a Settling Basin Area, containing at present a solitary settling basin and pump as a point of discharge of groundwater. This pond may be expanded or added to below this line, and may then be extracted itself once discharge is discontinued for Central Field Operations. Perimeter Keyway Extraction will maintain a perimeter slope no steeper than 1.25H:1 V, except for the perimeter shown in red along it's extraction limit, and respective toe where cut slopes will not exceed 2.00H:1V; as indicated (refer to Exhibit S: Stability Analysis for additional information). At the toe of the cut perimeter slope is the keyway that runs below the extracted deposit of the basin, into the bedrock, which allows the subsurface waters to flow to the settling basin and discharge pumps necessary to keep the cut basin dry during a time of extraction and reclamation of the affected perimeter slopes. The keyway dimensions may vary more or less from 4± to 8± feet in depth and 4± to 16± feet in width. Extraction must be broad enough to allow equipment to safely approach the toe and excise the bed dimensions where the resulting channel is sufficient to convey the groundwaters to the settling basin for discharge. l Adequacy Item 15: Keyway clarification VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I4 6.4.12 EXHIBIT L - Reclamation Costs Please Note: The graphic representation of the Perimeter Keyway Extraction and Core are idealized, and may vary in shape and size presented. Annual Reports will report on the nature and extent of affected lands and more properly reflect actual conditions on the ground in a given year of operations. UNI I TS OF DI STURBANCE: CE: The life of the operation is based upon a base rate of extraction approximating 8.0± acres of disturbance in a given year. This time will pulse with the market and may average 8.0+ acres, but could be faster or slower. Starting out, initial warranty necessary to cover the costs of reclamation for the extent of disturbance in a given year will also vary in time and circumstance, as the initial disturbance is generally less at the onset. So, a rate of disturbance can be estimated and the warranty adjusted incrementally with time and circumstance. Starting out in the initial projected 5 years of Operations, and incrementally thereafter, necessary warranty can be estimated and adjusted in incremental Units based upon the projected Life of the Operation. Essentially, a 30-35± year Life of Operations assumes a rate of extraction of approximately 8.0± acres per year. Considering the Mining -Regrading Schedule included as Table E-1 in Exhibit E, and the general development concept shown on Exhibit L: Financial Warranty Map, Raptor estimates for the initial 5 -year period, development of an initial 40 -acre excavation and development of a "Core" area in the Center Section of Central Field will result in creation of approximately 5,110 -foot of external perimeter pit wall. No reclamation or lining is anticipated in the initial 5 -year period. Raptor conservatively estimates for Financial Warranty purposes an approximately 50:50 split of wall excavated at 2H:1 V and 1.25:1V slopes. DEWATERI NG: Raptor assumes that the pit would be in an unlined state and if operations had ceased, would recharge to static water level requiring dewatering of the pit to allow reclamation operations to be completed. 100 hp. 4,500 gal./min. pump x (up to) 3 pumps @ 24 hours/day Volumes per Tract: VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I5 6.4.12 EXHIBIT L - Reclamation Costs Total Gallons — Central Field = 2,017,144,043.20± gallons 168.94 surface water acres = 11,940,002.6 gal./acre x 40.0± acres = 477,600,105± gallons for the initial 5 -year excavation. � = Avg. = 95,520,021.0 gal./8.0 acres x $ 0.000026/gal. discharge (refer to Kurtz est. utilizing similar pump and rates.) Total Cost for initial 40.0± acres of Discharge = 477,600,105± gallons x $ 0.000026/gal. discharge (refer to Kurtz est. utilizing similar pump and rates.) $ 12,417.60 Initial Discharge Cost for 40± acres It is assumed that ongoing dewatering will be required during reclamation of the pit and Raptor has allowed for 30 days once the pit has been dewatered. The estimated inflow rate to the fully excavated pits has been estimated at 14,700,000 gallons/day. The initial 40 -acre excavation area represents approximately 17% of total pit volume. Total discharge to maintain dry conditions for reclamation then is: 14,700,000 gallons/day x 17.1% x 30 days = 75,365,291± gallons $ 1,959.50 30 days Dewatering Cost for 40± acres $ 14,377.10 Total Dewatering Cost for 40± acres Please Note: 2The basins will be lined or otherwise segregated from the area groundwater, in order to liberate the water otherwise retained to supplement loss from evaporation in the unlined state. GRADI NG: As stated above, Raptor conservatively estimates for Financial Warranty purposes an approximately 50:50 split of wall excavated at 2H:1 V and 1.25:1V slopes along the extraction limits flanking WCR 396; and 2H:1V along the South Platte River levee, as shown on Exhibit D: Extraction Plan, and Exhibit L: Financial Warranty Map. Actual volume of fill required to grade at 3H:1V for a respective cut slope is determined in the graphics, below. Square Foot volume of backfill x 2,555 linear feet of slope divided by 27 will yield the required cubic yards needed for each section of highwall. A rate per Loose Cubic Yard of fill taken from the previously approved values determined by the OMLR, is used to better insure the integrity of the resulting values. Adequacy Item 28 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I6 6.4.12 EXHIBIT L - Reclamation Costs DIAGRA 40. OI depth .9 �P j, et/ 3H:1V_FINISHD � GRADE okra,/ FILE TO GRADE = 800 SOFT. • • 4 ACFRAM C.0'± epth Cc? FILL TO U to 4 „1 I:1V PINISHED GRACE. RADE - 1,400 SQ. FT Hauls are expected to be very short excavating material from the core area to establish final grade on those walls and placed on the exterior walls to establish the required grades and it may only require a wheel loader operating in load/carry/dump mode with a supporting tracked dozer. At most, the method of fill will utilize one (1) Excavator/Loader, two (2) Haul Trucks, and one (1) Sheep's Foot Compactor. Assuming a mean depth of advancing cut of 1.25H:1 V at the extraction limits of 40.0+ feet depth: VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I 7 6.4.12 EXHIBIT L - Reclamation Costs 2,555± lin.ft. (extraction front and side slopes) x 1,400.00± sq.ft. = 132,481± LCY 132,481± LCY x $ 0.56± per LCY. $ 74,189.63± fill along an 2,555 -foot extraction front cut at 1.25H:1 V. Assuming a mean depth of advancing cut of 2:1V at the extraction limits of 40.0± feet depth: 2,555± lin.ft. (extraction front and side slopes) x 800.00± sq.ft. (required fill — Diagram 1, above) = 75,704+ LCY 75,704± LCY x $ 0.56± per LCY. $ 42, 394.07 Sub Total -Grading to 3H :1 V along an 2,555 -foot extraction front cut at 2 H :1 V $ 74,189.63 Sub Total -Grading to 3H:1 V along an 2,555 -foot extraction front cut at 1.25H:1 V. + $ 42,394.07 Sub Total -Grading to 3H:1V along an 2,555 -foot extraction front cut at 2H:1V. $116,583.70 Total — Initial Grading. Liner I nstallation: Raptor has made allowance for liner installation on the regraded slope. Assumptions are that a 4 -foot thick liner will be installed keyed into bedrock at the base of the regraded slope and up the slope to approximately 5 -foot below the original surface elevation. It is further assumed that the interior wall of the regraded core area will be of similar length to the external wall. The keyway dimensions in bedrock are assumed to be 4x4 -foot. Perimeter liner at 5,110 lin.ft. x 2 x 111 sq.ft./ft x 4 ft. / 27 = 167,577 CY of liner placed at an estimated cost of $2.20/CY = $ 368,670.04. Keyway at the base of the 3:1 slope is estimated at 9,435 lin.ft. x 16 sq.ft./ft / 27 = 5,591 CY of liner placed an estimated cost of $2.20/CY = $12,300.30. $ 380,970.34 Total Liner Installation Cost Soil Demand AND Re -soiling of Affected Lands (refer to Exhibit D): VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I8 6.4.12 EXHIBIT L - Reclamation Costs Soil demand is limited to the cut basin slopes remaining above the static water level. For Central Field, the total area above the anticipated static water level of the basins is 11.82± acres. To estimate the area involved in resoiling the Center Section of Central Field - we'll use a percentage of the total perimeter length of the extraction limits involved: 15,075 Total perimeter length Central Field 5,110 External perimeter length Center -Central Field -extraction limits 5,110 Internal perimeter length on core area 10,220 Combined perimeter length 10,220 : 15,075 = 68% 11.82 acres x 68% = 8.01± acres requiring resoiling and revegetation (see Establishment of Vegetation over Affected Lands, below. At a depth of 0.5± feet, total volume = 8.01± acres x 0.5± feet of soil replacement, is: 8.01± acres x 43,560.0± sq.ft./acre - 27 cu.ft./cu.yd. = 6,464± cu.yds. @ 0.5' depth. The majority of soil placement can occur using the average placement distance of 600 ft., or less along embankments, (utilizing the same assumptions utilized at either Kurtz or Heintzelman Projects). 6,464± cu.yds of soil demand x $ 0.843 per LCY. $ 5,449.30 to replace 0.5± feet of soil over the existing affected lands remaining above the anticipated final water level at the Center of Central Field along the perimeter cut slopes at the extraction limits. 3Although Raptor does not anticipate the areas of soil replacement to be extensively compacted, an allowance for disking or scarifying 25% of the area at a cost of $28.5/acre. 8.01+ acres x 25% x $28.50/acre = $57.10 The processing area will also require soil replacement over the entire 21.35 acre area. 21.35± acres x 43,560.0± sq.ft./acre - 27 cu.ft./cu.yd. = 17,222± cu.yds. @ 0.5' depth. 17,222± cu.yds of soil demand x $ 0.843 per LCY. Adequacy Item 52 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 9 6.4.12 EXHIBIT L - Reclamation Costs $ 14,518.43 to replace 0.5± feet of soil over the existing affected lands in the processing area. 4Raptor assumes disking or scarifying this entire area at a cost of $28.5/acre. 21.35± acres x 100% x $28.50/acre = $608.48 $ 20,633.30 Total Soil Replacement Cost NOTE: Total Soil Demand for the entire Central Field and the North-West Field: 11.82± Acres Central Field 4.70± Acres North-West Field 16.52± Acres Total — Combined Soil Replacement Demand 16.52± Acres x 43,560 sq.ft./acre + 27 cu.ft./cu.yd. = 26,653.27± cu.yds. @ 1' depth.26,653.27± cu.yds. @ 1' depth soil + 2 = 13,326.63± total cu.yds soil required at 6 inches in depth at Central and North-West Fields for all basin slopes remaining above the anticipated static water level and below the extraction limits. Establishment of Vegetation over Affected Lands: The demand establishment of vegetation over the affected lands will also diminish proportionately with the planned extraction of the Tracts. For now, the total exposure is estimated as indicated above to be 8.01± acres for the Center Section of Central Field (see Soil Demand): NOTE: The cost for seed is estimated on Exhibit L - Table L-1: Primary/Preferred Re - vegetation Seed Mixture; however, the costs are known to fluctuate seasonally — and are estimates based on prior seasons. The seed mixture includes a substitute for mulch in the inclusion of a wheatgrass hybrid. The Division has historically agreed with and approved the inclusion of this hybrid as a substitute for mulch. The Optional Seed Mix will be used if the Primary Mixture fails, but costs less, so that cost is accounted for. These costs are as follows: $ 58.72± Preferred Seed Mix x 8.01+ acres $ 470.55± Sub -Total Seed The cost for applying seed is based upon information derived in proximity to the Northern Colorado economy. Costs for tilling, fertilizing and seeding are based upon estimates from Longs Peak Equipment Co. These costs, including labor, are reflected as follows: Adequacy Item 52 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 10 6.4.12 EXHIBIT L - Reclamation Costs $ 25.00± per acre Tilling $ 20.00± per acre Fertilizing $ 20.00± per acre Seeding $ 65.00± per acre Total Application Cost per Acre. x 8.01+ acres $ 520.87± Sub -Total — Application Costs $ 991.42± Sub -Total Re -vegetation (seed + application) Costs. Assume a 50± percent failure and add half the expense back into the total for reseeding, or. $ 495.71± Sub -Total Re -seeding costs $ 1,487.13± Excavation Area Re -vegetation Expense Re -vegetation of the 21.35 acre processing area is also estimated. $ 58.72± Preferred Seed Mix x 21.35± acres $ 1,253.67± Sub -Total Seed $ 65.00± per acre Total Application Cost per Acre. x 21.35± acres $ 1,387.75± Sub -Total — Application Costs $ 2,641.42± Sub -Total Re -vegetation (seed + application) Costs. Assume a 50± percent failure and add half the expense back into the total for reseeding, or $ 1,320.71± Sub -Total Re -seeding costs $ 3,962.13± Processing Area Re -vegetation Expense $ 5,449.27 Total Re -vegetation Cost Processing Area and Decommissioning: Raptor has estimated decommissioning costs for the Processing Area and Conveyor that will deliver mined material to that area. All plant and equipment in the processing area is portable and would have more value that the cost of loading and removing it. Decommissioning will involve the removal of concrete pads for processing equipment, concrete supports for truck scales and temporary buildings, and the conveyor infrastructure and belting. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 11 6.4.12 EXHIBIT L - Reclamation Costs Three 12 -inch -thick concrete pads are assumed in the processing area with dimensions 15- x 30 -feet, 15- x 60 -feet, and 15- x 25 -feet. Demolition and removal costs are estimated at $1.70/sq.ft. for 12" concrete pads. The truck scale will have concrete supports with an estimated volume of 10 CY. Additionally temporary buildings for the scale house/site entrance area and processing area will have concrete support blocks with estimated at 8 CY of concrete. Estimated costs for the concrete supports is $65.00/CY. Concrete pads: 1,725 sq.ft. x $1.70/sq.ft. _ $ 2,932.50 Concrete supports: 18 CY x $65.00/CY = $ 1,170.00 The decommissioning cost estimate for the conveyor structure is based on previous estimates provided by Divide Construction for other Raptor (previously Varra) operations and presented in Financial Warranty estimates. The costs have been updated to current using US Army Corps of Engineers Civil Works Construction Cost Index System (CWCCIS) indices. The regular conveyor structure in 40 -foot sections supported on concrete blocks is estimated to be 1,787± lin.ft. with an additional three extended span elevated truss sections 125 -foot in length for crossing WCR296 and the Big Thompson River. Decommissioning costs for the regular conveyor structure is estimated at $ 8.75/lin.ft. and the extended spans at $ 18,270.00 each. Conveyor decommissioning: 1,787± lin.ft. x $ 8.75/lin.ft. _ $ 15,640.18 Conveyor extended spans: 3 x $ 18,270.00 each = $ 54,810.00 $ 74,552.68 Total Processing and Conveyor Decommissioning Cost OTHER MI SCELLANEOUS COSTS: Mobilization and demobilization costs are based upon the Division's estimates, which are pending — but estimated in the summary at the beginning of this Exhibit L at $10,000. Demolition of Structures: None. Building Permits for structures will be obtain where required from the Weld County Building Department. Please Note: Since there is no possibility of the applicant in fully reproducing the Division's methods, utilizing similarities from past OMLR calculations is the VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION 12 6.4.12 EXHIBIT L - Reclamation Costs most viable and accurate means available for the applicant to derive reasonable estimates of per unit costs and should result in estimates very reliable with that of the Division. Extraction of the Core following completion of the Perimeter Extraction Keyway VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Pagel 6.4.13 EXHIBIT M - Other Permits and Licenses A statement identifying which of the following permits, licenses and approvals the Operator/Applicant holds or will be seeking in order to conduct the proposed mining and reclamation operations: effluent discharge permits, air quality emissions permits, radioactive source material licenses, the State Historic Preservation Office clearance, disposal of dredge and fill material (404) permits, permit to construct a dam, well permits, explosives permits, highway access permits, U.S. Forest Service permits Bureau of Land Management permits, county zoning and land use permits, and city zoning and land use permits. • Colorado Department of Health Storm Water Permit Approved (COG502213). • Colorado Department of Health Emission Permit N/A - Concrete Batch Plant. • Colorado Department of Health Emission Permit Pending Operations - Portable Equipment - Dry Plant • Colorado Department of Health Emission Permit Pending Operations - Wet Plant • Colorado Department of Health Emission Permit Approved (22WE0392) - Fugitive Dust - Mining Operations and related activities. • Weld County Special Use Permit N/A . • Colorado Division of Water Resources Well Permit Pending • State Historic Preservation Office clearance Pending . • U.S. Department of the Army Corps of Engineers No Permit Required Correspondence of 21 June 2021 . • Planned operations will not utilize or encounter materials, sources, or authorities over related lands and do not require permits for the following: radioactive source materials, construction of a dam, explosives, highway access, U.S. Forest Service, Bureau of Land Management, city zoning or land use. Refer to Approval from the City of Evans: Pending • Note: Any necessary permits for other planned or potential activities, including asphalt batch plants, recycling facilities and operations, etc., will be acquired prior to on -set of such plants, facilities or operations. All future permits will be submitted to the Division to update this list as necessary. Refer to Approval for Recycling Facilities and Operations from the City of Evans: Pending VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Pale 11 6.4.15 EXHIBIT 0 - Owner(s) of Record of Affected Land (Surface Area) and Owners of Substance to be Mined Owner(s) of Record of Affected Land (Surface Area): Raptor Materials, LLC 8120 Gage Street Frederick, CO 80516 Owner(s) of Substance to be Mined: Raptor Materials, LLC 8120 Gage Street Frederick, CO 80516 NOTE: Refer to Exhibit C-1: Existing Conditions Map for information regarding Other Owners of Record. VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page 6.4.19 EXHIBIT S - Permanent Man-made Structures Where the affected lands are within two hundred (200) feet of any significant, valuable and permanent man-made structure, the applicant shall: (a) (b) (c) provide a notarized agreement between the applicant and the person(s) having an interest in the structure, that the applicant is to provide compensation for any damage to the structure; or where such an agreement cannot be reached, the applicant shall provide an appropriate engineering evaluation that demonstrates that such structure shall not be damaged by activities occurring at the mining operation; or where such structure is a utility, the Applicant may supply a notarized letter, on utility letterhead, from the owner(s) of the utility that the mining and reclamation activities, as proposed, will have "no negative effect" on their utility. 6.5 GEOTECHNICAL STABILITY EXHIBIT (1) On a site -specific basis, an Applicant shall be required to provide a geotechnical evaluation of all geologic hazards that have the potential to affect any proposed impoundment, slope, embankment, highwall, or waste pile within the affected area. A geologic hazard is one of several types of adverse geologic conditions capable of causing damage or loss of property and life. The Applicant may also be required to provide a geotechnical evaluation of all geologic hazards, within or in the vicinity of the affected lands, which may be de -stabilized or exacerbated by mining or reclamation activities. (2) On a site -specific basis, an Applicant shall be required to provide engineering stability analyses for proposed final reclaimed slopes, highwalls, waste piles and embankments. An Applicant may also be required to provide engineering stability analyses for certain slopes configuration as they will occur during operations, including, but not limited to embankments. Information for slope stability analyses may include, but would not be limited to, slope angles and configurations, compaction and density, physical characteristics of earthen materials, pore pressure information, slope height, post -placement use of site, and information on structures or facilities that could be adversely affected by slope failure. (3) Where there is the potential for off -site impacts due to failure of any geologic structure or constructed earthen facility, which may be caused by mining or reclamation activities, the Applicant shall demonstrate through appropriate geotechnical and stability analyses that off -site areas will be protected with appropriate factors of safety incorporated into the VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I2 6.4.19 EXHIBIT S - Permanent Man-made Structures analysis. The minimum acceptable safety factors will be subject to approval by the Office, on a case -by -case basis, depending upon the degree of certainty of soil or rock strength determinations utilized in the stability analysis, depending upon the consequences associated with a potential failure, and depending upon the potential for seismic activity at each site. (4) At sites where blasting is part of the proposed mining or reclamation plan, the Applicant shall demonstrate through appropriate blasting, vibration, geotechnical, and structural engineering analyses, that off -site areas will not be adversely affected by blasting. 1The notarised agreements between the applicant and the person(s) having an interest in the structure, that the applicant is to provide compensation for any damage to the structure obtained as of January 03, 2023 are attached as an addendum to this Exhibit S. These are unchanged from previous submission of June 13, 2022 on file as an addendum to the application. Notarized agreements obained are with: DCP Midstream - Weld County Public Works City of Aurora Water Department - JDLB Farm LLC City of Evans - Central Weld Country Water District A complete list of structure owners is shown on Exhibit C-1: Existing Conditions Map and are attached as an addendum to this Exhibit S. To assure the stability of any significant, valuable, and permanent man-made structures that may exist within 200 feet of planned extraction activity, a complete and thorough stability analysis was performed by American Water Engineering Services, LLC. (AWES). Their reports of 23 December 2019 and 10 August 2022, are based upon on -site samples collected from the intended areas of extraction. Copies of the AWES reports are included at the back of this exhibit. The included AWES report verifies that the maximum planned extraction slopes of 1.25H:1V (and 2H:1V to the extend indicated by a Red Boundary along the Eastern Extraction Limit and a portion of the Southern Extraction Limit in Central Field) will not pose a hazard to such structures. The location of the extent of the 2H:1V extraction slope limits is shown in RED as indicated on the Exhibit C-2: Extraction Plan Map. l Adequacy Item 57 VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION Page I3 6.4.19 EXHIBIT S - Permanent Man-made Structures To the extent practical, operational setbacks will be observed consistent with those detailed under Exhibit D: Extraction Plan. Grading and reclamation of completed areas of extraction will reduce extracted slopes to a minimum of 3H:1V, or flatter, over a majority of the extraction area, in conformance with Rule 3.1.5(7). VARRA COMPANIES, INC. TWO RIVERS SAND GRAVEL AND RESERVOIR PROJECT MARCH 2022 A REGULAR IMPACT [112] CONSTRUCTION PERMIT APPLICATION - COLORADO DIVISION OF RECLAMATION MIING & SAFETY OFFICE OF MINED LAND RECLAMATION ERA ERO Resources Corporation Brad Janes, Forester Raptor Materials 8120 Gage St. Erie, CO. 80516 RE: Two Rivers OMLR Comment Dear Mr. Janes, Response for Wildlife Impacts: Denver Durango Hotchkiss Idaho 1842 North Clarkson Street, Denver, CO 80218 835 East Second Avenue, Suite 400, Durango, CO 81301 161 South 2nd Street, PO Box 932, Hotchkiss, CO 81419 7154 West State Street, Suite 398, Boise, ID 83714 November 30, 2022 My understanding is that mining is dependent on the aggregate market and the law of supply and demand. Both the timing (schedule) and amount of extraction will depend on the demand for materials and any single point in time. The mine must have maximum flexibility to mine to be able to respond to the market forces that are outside of their control. Maximum flexibility under the mine plan would allow for up to "four separate extraction teams" working concurrently. Under this "worse -case" scenario and adhering to the maximum of 16 acres of mining by each extraction team would result in a maximum of 64 acres being extracted at any one time. To put this into context, the majority of the extraction operations and soil stockpiling will be conducted in on the approximately 235 acres currently under high intensity farming. Extraction on 64 acres would only be a little over one -quarter of the agricultural land. Expanding this concept to include the riparian corridors within and immediately adjacent to the extraction area, there is over 1,000 acres between CR 378 (54th Street Road) and CR 394. A maximum of 64 acres being actively extracted would amount to only 6.4 percent of the 1,000 acres, leaving more than 93 percent of the area available to wildlife. Sincerely, Ronald Beane Senior Wildlife Biologist ERO Resources Corporation Consultants in Natural Resources and the Environment www.eroresources.com Top of pipe (ft.) Ground (ft.) Bottom Depth of Well (ft) Elevation of Well Bottom (ft.) Date MW -1 MW -2 Pit 124 Piezometer MW -3 MW -4 MW -5 MW -6 MW -7 MW -8 MW -9 MW -10 MW -11 MW -12 4711.51 4690.59 4687.85 4685.07 4683.09 4692.07 4689.98 4682.23 4694.55 4697.09 4694.44 4683.49 4708.61 4686.58 4683.82 4681.02 4678.95 4688.14 4686.04 4678.28 4690.60 4693.17 4690.37 4679.34 22.3 17.19 36.11 23.38 32.8 37.87 47.12 29.42 41.41 44.97 43.75 29.85 4689.21 4673.40 4651.74 4661.69 4650.29 4654.20 4642.86 4652.81 4653.14 4652.12 4650.69 4653.64 MW -1 MW -2 Measured Depth to Water (ft.) MW -3 MW -4 MW -5 MW -6 MW -7 MW -8 MW -9 MW -l0 MW -11 MW -12 9/15/2015 18.90 9.31 10.61 9.62 8.75 9.94 12.05 8.78 12.30 17.97 17.51 9.46 10/14/2015 19.08 9.81 10.80 9.79 8.90 10.81 12.29 8.80 12.66 17.63 17.29 9.48 11/13/2015 19.20 9.51 10.39 9.31 8.49 10.46 11.89 8.13 11.89 16.56 16.47 8.71 12/11/2015 19.32 9.63 10.51 9.43 8.62 10.71 12.03 8.51 12.46 17.30 17.17 9.18 1/12/2016 19.46 9.66 dry 9.34 8.55 10.81 12.18 8.62 12.40 17.26 17.32 9.25 2/12/2016 19.54 9.64 dry 9.40 8.62 10.67 12.08 8.54 12.15 16.92 17.04 9.17 3/11/2016 19.55 9.65 dry 9.49 8.70 10.65 12.05 8.70 12.34 17.32 17.38 9.44 4/12/2016 19.55 9.65 dry 9.67 8.82 10.41 11.92 8.30 11.64 16.31 16.54 8.87 5/9/2016 18.84 9.19 10.02 9.37 8.33 8.97 10.76 6.62 9.37 13.81 14.26 6.87 6/9/2016 18.57 8.21 8.61 7.34 6.82 8.80 10.34 6.68 9.52 14.15 14.46 7.18 7/12/2016 18.83 9.50 10.40 9.90 9.07 9.61 11.51 8.51 11.63 17.76 17.26 9.38 8/12/2016 19.07 9.75 dry 9.87 9.19 10.68 12.22 9.24 12.97 18.14 18.19 10.03 9/13/2016 19.22 9.64 dry 9.72 8.93 10.10 12.17 8.60 12.12 17.99 17.86 9.65 10/10/2016 19.21 9.92 dry 9.95 9.19 10.91 12.48 8.93 12.62 17.66 17.51 9.53 11/9/2016 19.13 9.91 dry 9.73 9.05 10.80 12.22 8.77 12.41 17.23 17.18 9.37 12/2/2016 19.09 9.98 dry 9.76 9.05 11.03 12.35 9.01 12.81 18.35 17.55 9.72 1/13/2017 19.11 10.05 dry 9.85 9.11 11.63 11.33 8.76 13.05 17.68 17.20 9.33 2/10/2017 19.11 10.71 dry 10.53 9.76 11.66 13.01 9.45 13.24 17.97 17.96 10.09 3/10/2017 19.15 10.77 dry 10.66 9.91 11.79 13.09 9.58 13.36 18.17 18.07 10.21 4/11/2017 19.81 10.81 dry 10.63 9.93 11.90 13.23 9.95 13.92 19.10 18.69 10.66 5/12/2017 19.13 10.18 dry 9.86 9.18 11.04 12.68 8.78 12.06 17.00 17.09 9.23 6/9/2017 18.08 9.29 10.15 9.41 8.67 9.64 11.13 7.70 11.05 15.73 15.83 8.21 7/13/2017 18.61 9.62 dry 9.89 9.36 10.09 11.98 9.18 12.43 18.21 18.08 10.03 8/11/2017 18.75 9.14 dry 9.19 8.58 9.71 11.74 7.21 11.30 16.84 16.39 8.78 9/12/2017 18.89 9.98 dry 10.08 9.53 10.77 12.57 9.38 12.61 18.21 18.27 10.04 10/13/2017 18.77 9.87 dry 9.70 9.12 10.82 12.31 8.83 12.46 17.59 17.51 9.46 11/10/2017 18.78 9.86 dry 9.59 9.01 10.88 12.34 8.73 12.39 17.31 17.33 9.35 12/8/2017 18.86 9.98 dry 9.88 9.25 10.95 12.34 8.82 12.56 17.51 17.45 9.45 1/12/2018 18.94 10.03 dry 9.78 9.20 11.14 12.49 8.97 12.76 17.72 17.70 9.63 2/9/2018 19.00 10.12 dry 9.92 9.36 11.31 12.63 9.21 13.06 18.09 18.09 9.92 3/9/2018 19.05 10.27 dry 10.12 9.55 11.39 12.76 9.26 13.09 18.12 18.10 9.96 4/12/2018 19.09 10.37 dry 10.19 9.69 11.55 12.87 9.59 13.37 18.49 18.56 10.34 5/10/2018 18.93 10.31 dry 10.25 9.68 11.21 12.76 9.26 12.75 18.03 17.97 9.94 6/6/2018 18.87 9.98 dry 9.91 9.33 10.75 12.31 9.09 12.56 17.58 17.68 9.84 7/10/2018 19.13 10.07 dry 10.23 9.75 10.84 12.73 9.78 12.93 19.27 18.39 10.52 8/10/2018 19.15 9.85 dry 10.06 9.61 10.86 12.63 9.74 12.87 19.05 18.78 10.56 9/7/2018 19.27 10.33 dry 10.53 10.03 11.25 13.03 9.53 12.59 17.71 18.03 10.11 10/12/2018 19.31 10.33 dry 10.19 9.69 11.38 12.96 9.40 12.83 17.59 17.92 10.02 11/9/2018 19.30 10.09 dry 9.81 9.30 11.11 12.60 9.12 12.66 17.48 17.64 9.81 12/7/2018 19.35 10.17 dry 9.96 9.46 11.36 12.72 9.41 13.10 18.12 18.14 10.17 1/10/2019 19.36 10.29 dry 10.11 9.60 11.51 12.89 9.49 13.21 18.24 18.20 10.21 2/12/2019 19.40 10.27 dry 10.18 9.62 11.41 12.80 9.37 13.03 17.80 18.01 10.06 3/8/2019 19.39 10.29 dry 10.13 9.59 11.39 12.79 9.35 12.98 17.76 17.94 10.01 4/10/2019 19.36 10.30 dry 10.22 9.67 11.36 12.73 9.51 13.26 18.32 18.19 10.31 5/10/2019 19.27 10.43 dry 10.25 9.78 11.57 13.05 9.46 12.77 17.32 17.88 9.93 6/7/2019 19.12 10.22 dry 9.90 9.49 11.21 12.78 9.48 12.88 17.86 18.08 10.19 7/9/2019 19.21 9.36 dry 9.15 8.54 8.99 11.33 7.36 9.25 14.74 14.89 7.69 8/9/2019 19.29 9.49 dry 9.98 9.49 9.83 11.99 9.04 11.48 18.16 17.76 9.78 9/6/2019 19.41 9.94 dry 10.07 9.61 10.76 12.59 9.69 12.72 18.34 18.50 10.36 10/9/2019 19.40 10.13 dry 10.12 9.61 11.08 12.75 9.46 12.80 18.08 18.11 10.13 11/8/2019 19.33 9.97 dry 9.68 9.16 11.02 12.50 9.11 12.67 17.92 17.70 9.77 12/6/2019 19.31 10.13 dry 9.92 9.37 11.12 12.60 9.08 12.58 17.67 17.55 9.62 Top of pipe (ft.) Ground (ft.) Bottom Depth of Well (ft) Elevation of Well Bottom (ft.) MW -1 MW -2 Pit 124 Piezometer MW -3 MW -4 MW -5 MW -6 MW -7 MW -8 MW -9 MW -10 MW -11 MW -12 4711.51 4690.59 4687.85 4685.07 4683.09 4692.07 4689.98 4682.23 4694.55 4697.09 4694.44 4683.49 4708.61 4686.58 4683.82 4681.02 4678.95 4688.14 4686.04 4678.28 4690.60 4693.17 4690.37 4679.34 22.3 17.19 36.11 23.38 32.8 37.87 47.12 29.42 41.41 44.97 43.75 29.85 4689.21 4673.40 4651.74 4661.69 4650.29 4654.20 4642.86 4652.81 4653.14 4652.12 4650.69 4653.64 Measured Depth to Water (ft.) 1/10/2020 19.26 10.19 dry 10.03 9.50 11.26 12.68 9.21 12.57 18.07 17.83 9.80 2/7/2020 19.19 10.23 dry 10.04 9.51 11.36 12.78 9.31 13.00 18.13 18.02 9.91 3/11/2020 19.15 10.24 dry 10.08 9.57 11.41 12.85 9.37 13.03 18.15 18.07 9.97 4/9/2020 19.07 10.13 dry 10.12 9.57 11.15 12.60 9.38 12.96 18.10 17.95 10.01 5/8/2020 18.94 10.12 dry 9.96 9.51 11.13 12.59 9.53 12.89 17.89 17.88 9.99 6/9/2020 19.05 10.02 dry 9.93 9.45 10.64 12.29 9.08 12.04 17.07 17.43 9.46 7/10/2020 19.12 9.91 dry 9.91 9.46 10.83 12.53 9.89 12.72 18.51 18.70 10.47 8/7/2020 19.04 10.03 dry 10.06 9.64 10.78 12.72 9.97 12.39 18.22 18.53 10.52 9/11/2020 19.14 10.23 dry 9.99 9.59 11.22 12.96 9.72 12.36 17.42 17.93 10.11 10/7/2020 19.21 10.40 dry 10.28 9.88 11.39 13.01 10.03 12.89 18.31 18.59 10.55 11/13/2020 19.14 10.07 dry 9.88 9.41 11.02 12.62 9.53 12.38 17.63 17.70 10.06 12/9/2020 19.16 10.05 dry 9.92 9.45 10.88 12.49 9.43 12.20 17.38 17.61 9.92 1/8/2021 19.18 10.07 dry 9.91 9.32 10.92 12.47 9.40 12.26 17.39 17.67 9.89 2/8/2021 19.20 10.23 dry 10.08 9.60 11.30 12.79 9.89 12.87 18.06 18.29 10.42 3/9/2021 19.17 10.23 dry 10.05 9.55 11.16 12.76 9.59 12.43 17.43 17.71 9.98 4/9/2021 19.17 10.11 dry 10.02 9.51 11.08 12.54 9.71 12.80 18.18 18.16 10.25 5/7/2021 19.15 10.28 dry 10.23 9.67 10.90 12.64 9.15 12.01 17.13 17.23 9.48 6/11/2021 19.10 8.27 8.72 7.66 7.38 9.30 10.93 8.34 10.47 16.08 16.23 8.61 7/8/2021 19.24 9.12 10.09 8.99 8.68 9.81 11.56 9.02 11.66 17.24 17.13 9.40 8/10/2021 19.31 9.79 dry 9.71 9.25 10.59 12.34 9.45 12.40 18.06 17.85 9.91 9/10/2021 19.37 10.17 dry 10.08 9.67 11.23 12.76 10.09 13.16 18.87 18.90 10.53 10/8/2021 19.41 10.31 dry 10.08 9.64 11.47 12.98 9.99 13.20 18.68 18.78 10.43 11/10/2021 19.36 9.91 dry 9.74 9.23 10.94 12.42 9.36 12.45 17.91 17.82 9.78 12/9/2021 19.38 10.07 dry 9.85 9.34 11.07 12.55 9.44 12.51 17.73 17.72 9.86 1/10/2022 19.41 10.07 dry 9.94 9.49 11.25 12.69 9.96 12.96 18.23 18.45 10.47 2/11/2022 19.40 10.22 dry 10.03 9.51 11.26 12.80 9.69 12.70 17.80 18.04 10.16 3/14/2022 19.40 10.10 dry 9.89 9.39 11.18 12.63 9.73 12.76 17.89 18.09 10.23 4/11/2022 19.40 10.22 dry 10.09 9.60 11.26 12.72 9.92 12.94 18.08 18.33 10.41 5/10/2022 19.41 10.51 dry 10.46 10.02 11.47 13.11 10.32 13.11 18.10 19.05 10.78 6/10/2022 19.48 9.86 dry 9.83 9.36 10.51 12.26 9.53 12.27 17.57 17.62 9.91 Two Rivers Sand Gravel Reservoir Project Exhibit G Addendum 11 Water Well Detail Permit Number Latitude Longitude Owner Permit Status Construction Date Permit Category Use(s) 13950 -R -R 40.35129 -104.769112 DOS RIOS ESTATES WTR CO Well Constructed 10/11/1989 General Purpose Irrigation 270-R 40.342653 -104.785728.SHABLE, ALVA L Well Constructed 6/20/1955 General Purpose Irrigation 8303 -R -R 40.342343 -104.782483 VARRA COMPANIES INC (VARRA, GARRETT) Well Constructed 11/14/1989 General Purpose Irrigation 8304-R 40.342642 -104.780991 VARRA COMPANIES INC (VARRA, GARRETT) Well Constructed 6/30/1952 General Purpose Irrigation 320422- 40.339043 -104.78599 LAFARGEHOLCIM / AGGREGATE INDUSTRIES Well Constructed 1/22/2021 Monitoring/Observation Monitoring/Sampling 79087--A 40.339404 -104.776829 SORIN NATURAL RESOURCES PARTNERS LLC Well Constructed 5/12/1975 Residential Domestic 1282 -R -R 40.341719 -104.76314 DIXIE WATER, LLC Well Constructed 4/23/1976 General Purpose Irrigation 78568-F 40.349824 -104.761416 SORIN NATURAL RESOURCE PARTNERS LLC Well Constructed 9/24/2014 General Purpose Industrial ,American Water Engineering Services, LLC August 30, 2022 Raptor Materials, LLC 8120 Gage Street Frederick, Colorado 80516 Attn: Garrett Varra RE: Comments on Dewatering Analysis 112C Permit Application Adequacy Review DRMS Letter Date August 5, 2022 Dear Mr. Varra: This letter report presents responses to a review of a dewatering analysis performed by American Water Engineering Services, LLC (AWES) for the Raptor Materials, LLC (Raptor) mine located near Evans, Colorado. This report is intended to address the issues raised in the Division of Reclamation, Mining and Safety (DRMS) letter dated August 5, 2022. The review letter is provided as Attachment A. The following summarize DRMS comments by item. 1. Comment 6 — Please justify the assumption of anisotropy and the chosen K values for the sand and gravel aquifer. Westest, LLC of Lakewood Colorado conducted a geotechnical investigation, which consisted of drilling 12 soil borings by hollow stem auger techniques and obtaining representative soil samples to determine soil strength and grain size distribution. The borings were also completed as groundwater monitoring wells. The grain size distribution curves show the 90% retained (d10) to vary between 0.2 and 0.3 millimeters (mm). The Allen Hazen equation as presented by Freeze and Cherry, Raghunath and others provides rough estimates of hydraulic conductivity. Use of the equation K=Ad210, where K is hydraulic conductivity in cm/s, d10 is in mm and A is a constant equal to one. Based on grain size curves the hydraulic conductivity is estimated to vary between 113 and 255 feet per day. The author has also been involved with Varra Inc., mining operations since 1989 and numerous evaluations at operating mines have indicated K values ranging from 50 feet to 300 feet per day. Schneider 1983, reported K values ranging between 15 and 300 feet per day in the alluvial valley deposits, which support past analyses. The clay, sand and gravel deposits are alluvial and have bedding planes. Hydraulic conductivities are smaller in directions normal to bedding than in directions parallel to bedding. This by definition is anisotropic. As different horizontal K values were assigned for the unconsolidated deposits the aquifer within the model area is more correctly described as heterogeneous and anisotropic. 2. Comment 7 — Please describe how these wells were used for pre -mining aquifer characterization (besides the collections of water level data). The wells are small diameter i m1/t%4'I _ S 4SC9 Four Star Court, Fort Collins, CO 8524 - 97C -59C-387 Technical Adequacy Review Two Rivers Application August 30, 2022 Page 2 and were not used in aquifer characterization other than measured water levels. The soils strength and grain size data were used in slope stability analyses and K estimation. 3. Comment 8 — How many vertical layers are in the model? What are the thicknesses? Two layers were used to simulate unconsolidated alluvial deposits and bedrock. Two hydraulic conductivity zones were identified for the coarse alluvial deposits and finer grained upper terrace deposits located near the northwest model boundary. The thickness of the unconsolidated deposits varied between 12 and 44 feet in the vicinity of the mine. A plate depicting vertical layers and assigned conductivities is provided in the updated report. 4. Comment 9 — Is recharge from precipitation accounted for in the model, or is its impact assumed to be negligible? Lindsey et al., 1982, provides an average annual evaporation from shallow lake evaporation map, which indicates the study area to have between 48 and 52 inches of evaporation. Given the high potential evaporation a recharge of 10% of the annual precipitation total of 15 inches per year (1.5 inches) was used. 5. Comment 10 — Please discuss the validity of the model boundary conditions in the light of the final pit configuration (which is assumed to be that shown on the maps in the PAP). The central pit configuration was changed after my analysis without my knowledge. I have modified the constant head boundary in the central pit with little change to the predicted drawdown. An updated analysis is provided. 6. Comment 11 — Please discuss the characterization of the pre -mining water table. How reliable is the data from MW -1? How do you account for the steeper gradient? Are there any other data points in the north study area to improve the characterization? AWES was provided roughly four years of monthly water level data collected from the 12 piezometers. The levels were collected by using an electric water level meter marked to 1/100 of a foot. The top of casing and ground surface were surveyed by a professional land surveyor and water levels typically collected by a registered professional engineer. The quality of the data is considered excellent. The approximate well locations within the property boundary are depicted on Figure 1. As can be seen the spatial distribution of the wells provide excellent gradient control. The boring log of MW -1 shows that water was not encountered during drilling (indicating low permeability) and that the water table surface is located in silty, clayey sand. These soils will have orders of magnitude less permeability than clean sands or gravels which account for steeper gradients. Well records from the Division of Water Resources were researched and only one well record in close proximity to the northern model boundary was available. The well log is provided as Attachment B and the well location is depicted on Figure 1. The well log shows a sustained yield of 5 gallons per minute over a two hour interval with a drawdown of 7 feet, with the water table located primarily in shale. Using a form of Darcy's Law a permeability (K) of 13.76 feet per day is calculated based on reported data. The topographic gradient is dramatically steeper north of the alluvial valley and dips sharply to the south, southeast — groundwater flow direction and gradient typically mimic topography, which accounts for the steeper gradients. Awrs 4SC9 Four Star Court, Fort Collins, CC SC424- - )1C-i JC-3 SC7 Technical Adequacy Review Two Rivers Application August 30, 2022 Page 3 7. Comment 12 — Please clarify the initial calibration process. Please discuss the validity of the model in the north study area. The model was not calibrated using model assigned monitoring wells. These wells (measuring points) were added after the model calibrations. The measured depth to bedrock and surveyed ground surface elevations, in combination with topographic map elevations, were input into Surfer - a three dimensional contouring software package. The bedrock and ground surface elevations were then imported into Visual Modflow (VMOD). Water table elevations measured in on -site piezometers over a four year period were averaged and these elevations were used in the calibration process. A site survey also provided surface water elevations of the South Platte and Big Thompson rivers. The model boundary was superimposed over a topographic map and the author generated hand drawn contours that best reflected measured groundwater and surface water elevations. In the extreme northwest model area the elevations of the intermittent stream beds were used as water table elevations. General head boundaries were assigned to the model perimeter and head elevations were assigned where hand drawn elevations intersected the model boundary. The model was then run and predicted heads were compared to measured values. This process took several iterations as water table gradients changed dramatically throughout the model boundary. After the calibration process was completed the "cell inspector" function was used to determine the predicted head elevations for model assigned wells. The head elevations at the model assigned wells prior to pumping or lining were used as a baseline to measure the effects of dewatering and mine wall lining. It also should be noted that the Big Thompson River is a groundwater divide and groundwater conditions north of the river have little to no effect on dewatering simulations. 8. Comment 13 — Please simulate the dewatering of the full extent of the mined area. Please estimate the time to achieve steady state conditions. Dewatering simulations for the total area mined are provided in an updated report attached to this submittal. Bear 1979, presents solutions for the time required to reach steady state and can be estimated by the following equation. R(t) = 1.9(Tt/ne)1/2 Where: R(t) = radius of influence as a function of time (ft.) T = transmissivity (ft2/day) t = time (days) ne = effective porosity (dimensionless) Assuming a saturated thickness of 35 feet, a transmissivity of 4375 ft2/day, an effective porosity of 0.27 and a radius of influence of 4000 feet the time to reach steady state is calculated to be 273 days. However dewatering will be progressive during mining and an estimated 1000 days will be required to achieve this radius of influence during early dewatering operations. AWFS x_809 Four Star Court, Fort Collins, CO 80524_ - 97C-590-3807 Technical Adequacy Review Two Rivers Application August 30, 2022 Page 4 9. Comment 14 — Please add a column to Table 1 showing the predicted water levels under the pit dewatering scenario. The table should show the fullest extent of the potential drawdown caused by the mine operation. The table has been modified as requested. 10. Comment 15 - Please update the report to present any relevant analytical solutions that support the conclusion. Relevant analytical solutions have been added to the dewatering report. If you have any questions or need additional information, please contact me at (970) 590-3807. Sincerely, AWES, LLC Joby Adams, P.G., REM Principal/Hydrogeologist firtALIWUS 4.8 9 Four Star Court, Fort: Collins, CO 8 524 - 97C -59C -38C7 AMERICAN WATER ENGINEERING SERVICES, LLC GROUNDWATER MONITORING PLAN RAPTOR TWO RIVERS MINE 14822 396 HWY EVANS, COLORADO AWES PROJECT tt 2022-RM-P124 November 2022 Prepared for: Raport Materials, LLC. 8120 Gage Street Frederick, CO 80516 Lea r __t GoosIeeafh Dee /19/2011 tat 10:34/131" lob -101 1126ber - ele 1011 ft de alt 1h11 1'r Prepared by: AWES, LLC 4809 Four Star Ct. Fort Collins, CO 80524 ;,Lows 48C1 Four Star Court, Fort Collins, CC SCS24 AWES, LLC Table of Contents 1.0 INTRODUCTION 1 1.1 Objectives 1 1.2 Background Information 1 2.0 GROUNDWATER MONITORING 1 2.1 Monitoring Well Installation 1 2.2 Groundwater Level Measurements 2 2.3 Chemical Analyses 2 2.4 Drawdown/Mounding Modeling 2 2.5 Contingency Plan and Abatement 2 3.0 ORGANIZATION AND STAFF ASSIGNMENTS 3 3.1 Project Personnel 3 3.2 Subcontractors 3 4.0 OVERVIEW - QUALITY ASSURANCE/QUALITY CONTROL 3 5.0 REMARKS 4 FIGURES Figure 1- Site Location Map Figure 2 — Monitoring Well Location Map APPENDIX Appendix A — Boring Logs Appendix B — Methods and Procedures AWES, LLC GROUNDWATER MONITORING WORK PLAN VARRA TWO RIVERS MINE PROJECT WELD COUNTY, COLORADO 1.0 INTRODUCTION This Groundwater Monitoring Plan (Plan) has been prepared by AWES, LLC on behalf of Raptor Materials, LLC (Raptor) for the proposed Two Rivers mine project located in Weld County, Colorado (Figure 1). The current mining plan includes dry mine gravel extraction from two pits that will encompass approximately 270 acres. This plan will be submitted to the Division of Reclamation, Mining and Safety (Division) as part of Raptor's mine permit application. 1.1 Objectives The objectives of this Plan are to identify potential liabilities with the extraction of aggregate under semi - saturated conditions. Specific objectives for the Raptor project are described below. • To determine the aerial extent of drawdown associated with mine dewatering; • To determine the effects of dry mine aggregate extraction on local hydrology and water quality; • To generate predictive models on possible adverse drawdown in adjacent domestic wells; and • To determine the effects of lined pit reclamation on the local groundwater flow regime. 1.2 Background Information The proposed gravel quarry is located in sections 3 and 4 of Township 4 North, Range 66 West and sections 33 and 34, Township 5 North, Range 66 West of the 6th Principal Meridian. The surrounding land use consists of agricultural, rural residential and oil and gas gathering. The proposed mine area occupies an estimated 380 acres with an extraction area of 270 acres. The anticipated extraction depth will vary between 12 and 44 feet below grade. Information provided by geotechnical investigations, monitoring well water level data and water resource evaluation reports document the local and regional hydrogeology. In January 2015, 12 soil borings were drilled from ground surface to bedrock to determine the potential aggregate mass within the proposed mine boundary. These borings were completed as one -inch groundwater monitoring wells and the well locations are depicted on Figure 2. The depth to bedrock within the proposed mine pit boundaries varied between 12 and 44 feet below ground surface. In general soil conditions consist of less than one to six feet of top soil and sandy clay underlain by sand and gravel with occasional clay and poorly graded sand lenses. The coarse alluvial deposits are underlain by bedrock which consists of siltstone, sandstone and claystone. 2.0 GROUNDWATER MONITORING 2.1 Monitoring Well Installation As mentioned in January 2015, WesTest, LLC drilled 12 soil borings from ground surface to bedrock using hollow stem auger techniques and completed the borings as one -inch groundwater monitoring wells. The 1 AWES, LLC construction details of the monitoring wells were not reported in WesTest's summary report but are identified as one -inch monitoring wells by the operator. Boring logs are presented in Appendix A. 2.2 Groundwater Level Measurements All monitoring wells were surveyed to the nearest 0.01 foot for vertical elevation and to the nearest 0.5 foot for horizontal location. Groundwater level measurements in all wells have been measured by an electric water level indicator on a monthly basis since September 2015. Raptor will continue to measure water levels on a monthly basis during dewatering operations. After reclamation groundwater levels will be measured on a quarterly basis for one year and then on an annual basis until the mine permit has been withdrawn. 2.3 Chemical Analyses Table 1 presents field parameters and laboratory analyses for samples obtained from no less than one up - gradient and two down gradient wells. Water levels will be measured from all wells on a monthly basis. Two baseline samples will be obtained from one upgradient and two downgradient wells no less than two months apart. The wells will be sampled for the laboratory parameters if there is an exceedance in the stormwater laboratory parameters. On an annual basis field parameters of pH, specific conductance and temperature will be measured in waters obtained from the selected wells after three well bore volumes have been evacuated. Table 1— Analytical Parameters Parameter Analytical Method Units Water Standard Quality Frequency Field Parameters pH Measurement Direct s.u. 6.5-9 Annual Specific Conductance Measurement Direct uS/cm N/A Annual Temperature Measurement Direct °F N/A Annual Water Level Measurement Direct Ft. N/A Monthly Laboratory Parameters Arsenic, Total EPA 200.8 ug/L 10 Two baseline samples/stormwater upset Selenium, Dissolved EPA 200.8 ug/L 50 Two baseline samples/stormwater upset 2.4 Drawdown/Mounding Modeling Water level data will be used for drawdown and mounding analyses. The average of monthly water level data over a one year period will be input into the geostatistical software package Surfer®. Variations in pre -mining water levels will be presented on a two dimensional contour map and will be compared to numerical predictions and will be provided to the Division upon request. 2.5 Contingency Plan and Abatement As mine dewatering will create a groundwater sink it is highly unlikely that changes in groundwater quality will occur due to mining activities. As water levels will be measured on a monthly basis unanticipated 2 AWES, LLC groundwater drawdown can be predicted and evaluated for possible injury to off -site well owners. The extent of any abatement will be determined by negotiations with affected parties. 3.0 ORGANIZATION AND STAFF ASSIGNMENTS 3.1 Project Personnel Ms. Tana Kersting of Raptor will serve as field coordinator and will be responsible for obtaining water levels and will perform or supervise water quality sampling. Mr. Garrett Varra of Raptor will provide senior review of field and analytical data and will serve as project coordinator. 3.2 Subcontractors Subcontracted services for this project will include Technology Laboratories, Inc., of Fort Collins, Colorado who will perform analytical services. 4.0 OVERVIEW - QUALITY ASSURANCE/QUALITY CONTROL Quality assurance (QA) is a management system for ensuring that all information, data, and decisions resulting from the project are technically sound and properly documented. Quality Control (QC) is the functional mechanism through which quality assurance achieves its goals. Quality control programs, for example, define the frequency and methods of checks, audits, and reviews necessary to identify problems and dictate corrective action to resolve these problems, thus ensuring data of high quality. Thus, a QA/QC program pertains to all data collection, evaluation, and review activities that are part of the project. The use of qualified personnel for conducting various portions of the project is of paramount importance to an effective QA/QC program. This pertains not only to qualified QA/QC specialists, but also to specialists in other fields, including hydrogeologists, air quality specialists, soil scientists, analytical chemists and other scientific and technical disciplines. The project manager should ensure that qualified specialists, primarily individuals with the proper education, training, and experience, including licensed or certified professionals, are directing and performing the various project activities. The same general principles apply to selection of contractors and/or outside laboratories. Another important aspect of the QA/QC program is the communication between the QA/QC organization and the project manager. Regular appraisal by the project manager of the quality aspects related to the ongoing project data -gathering efforts provides the mechanism whereby the established objectives may be met. QA/QC procedures should provide details relating to the schedule, information to be provided, and the mechanism for reporting to the project manager. Reports to the project manager should include: • Periodic assessment of measurement data accuracy, precision, and completeness; • Results of performance audits; • Results of system audits; • Significant QA/QC problems and recommended solutions; and • Resolutions of previously stated problems. 3 AWES, LLC 5.0 REMARKS The scope of work is based upon current available information and our understanding of this project. As the project develops, changes to the project scope of work may be required. If changes in the scope of work are dictated by the needs of the project, these changes will be presented prior to implementation. This Groundwater Monitoring Plan was prepared by AWES, LLC. Date Joby L. Adams, P.G., REM Principal/Hydrogeologist 4 Figure 1- Site Location Map Varra Companies - Conrad Capital Group Property f l rl / II .a' r+" T i �". UN 4738 9 e: r / De 7-4 6b 4728 I • a *. 4723 - 4 ._ I II 1 MILE 0 1000 FEET 0 500 1000 METERS Map created with TGPO! ® ©2002 National Geographic (www_nai an.alea raphic _cooin'topci) ll p� 4727 * WOOS_ 47.0 43 4725 • w I` O s S`3 0 APPENDIX A SOIL BORING LOGS ST 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net Depth (ft.) Boring 1 LOGS OF BORINGS PROJECT: Two Rivers Property WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler Depth (ft.) Boring 2 REPORT DATE: February 12, 2015 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 3 0 5 10 15 20 25 30 35 40 45 50 50/4 50/5 W = 16.1 DD= 114.0 0 5 10 15 20 25 30 35 40 45 50 50/4 W = 15.9 DD = 108.8 #200 = 67.3 Qu = 11,090 0 5 10 15 20 25 30 35 40 45 50 0 ..u. 150/5 W=14.1 DD= 118.6 Qu = 18,440 FIGURE 2 ST 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net Depth (ft.) Boring 4 LOGS OF BORINGS PROJECT: Two Rivers Property REPORT DATE: February 12, 2015 WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler Depth (ft.) Boring 5 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 6 0 5 10 15 20 25 30 35 40 45 50 0 25/12 W = 21.1 DD = 105.2 0 5 10 15 20 25 30 35 40 45 50 #4=57 #10 = 36 #40 = 16 #200 = 5.9 #4 = 84 #10 = 60 #40 = 22 #200 = 1.9 ////////////// ////////////// 50/3 W = 20.1 LL=38 PI = 14 #200 = 88.4 0 5 10 15 20 25 30 35 40 45 50 0 • 4 ........................... ........................... 50/5 W = 15.6 DD = 115.9 Qu = 18,050 1 50/0 FIGURE 3 ST 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net Depth (ft.) Boring 7 LOGS OF BORINGS PROJECT: Two Rivers Property REPORT DATE: February 12, 2015 WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler Depth (ft.) Boring 8 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 9 0 5 10 15 20 25 30 35 40 45 50 #4 = 60 #10 = 30 #40 = 11 #200 = 3.8 2 0 50/4 0 5 10 15 20 25 30 35 40 45 50 0 Mat MIMMTNIT /%%%%%%%%%%%%i ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// V.......................... .......................... I' 50/3 0 5 10 15 20 25 30 35 40 45 50 #4=86 #10=61 #40 = 18 #200 = 4.1 d 50/6 W = 24.6 DD = 99.3 Qu = 4,120 FIGURE 4 �T25T 627 Sheridan Boulevard • Lakewood, CO 80214 303.975.9959 • office@westest.net Depth (ft.) Boring 10 LOGS OF BORINGS PROJECT: Two Rivers Property REPORT DATE: February 12, 2015 WesTest PROJECT NO.: 440515 CLIENT: Varra Companies LOGGED BY: Zachary Wheeler Depth (ft.) Boring 11 DATE DRILLED: January 27-30, 2015 DRILLER: Dakota Drilling Depth (ft.) Boring 12 0 5 10 15 20 25 30 35 40 45 50 U 150/3 0 5 10 15 20 25 30 35 40 45 50 0 ////////////// rrrrrrrrrrrrrr 11111111111111 rrrrrrrrrrrrr/ ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// "III", //////////////////////////////////////// /1/11/1/////// ////////////// ////////////// ////////////// ////////////// ////////////// ////////////// i _ ................... .................... .................... .................... i 50/3 0 5 10 15 20 25 30 35 40 45 50 #4 = 69 #10 = 55 #40 = 22 #200 = 2.7 0 50/4 FIGURE 5 627 Sheridan Boulevard • Lakewood. CO 80214 303.975.9959 • office@westest.net LEGEND AND NOTES TWO RIVERS PROPERTY PROJECT NO.: 440515 i X 0 0 Topsoil Overburden, silty sandy CLAY to silty SAND, TRACE GRAVEL, stiff, slightly moist to moist, light brown to dark brown SAND, occasional GRAVEL, loose to medium dense, slightly moist to wet, tan to brown SAND, with gravel, loose to medium dense, slightly moist to wet, tan to brown SAND, gravelly, medium dense, wet, tan to brown Silty clayey SAND, loose to medium dense, moist to wet, brown CLAY, soft to medium stiff, very moist to wet, brown SANDSTONE-CLAYSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, gray to brown CLAYSTONE BEDROCK, very hard, moist to very moist, gray SANDSTONE-SILTSTONE BEDROCK, interbedded, hard to very hard, moist to very moist, brown to gray Indicates bulk sample location Indicates 2" Modified California Barrel Sample location (ASTM D 3550) Water level at number of days indicated Caved at number of days indicated W Indicates % moisture (ASTM D 2216) DD Indicates dry density (pcf) (ASTM D 7263) Qu Indicates unconfined compressive strength (psf) (ASTM D 2166) 50/4 Location of sample; indicates that 50 blows with a 140 pound hammer, falling 30 inches, were required to drive a 2 -inch diameter sampler 4 inches. The borings were drilled on January 27, 2015 through January 30, 2015, with a Longyear 66 Drill Rig and 4 1/4 I.D. Hollow Stem Augers. 2. The stratification lines represent the approximate boundary between soil types and the transition may be gradual. 3 4 The boring logs show subsurface conditions on the date and at the locations indicated. It is not warranted that they are representative of subsurface conditions at other locations and times within the project area. The boring locations were staked in the field by referencing to existing landmarks. The boring locations are adequate for purposes of this report, but should be considered as approximate for any other use. 5. Free water was encountered in the borings as indicated. Fluctuations in the water level should be anticipated. FIGURE 6 APPENDIX B METHODS AND PROCEDURES AWES, LLC METHODS AND PROCEDURES Groundwater Sampling All monitoring wells where groundwater is encountered will be sampled according to the protocols listed below. All pertinent information will be recorded on a sampling information form or field book. Field Protocol Step 1- Measure water level. Step 2 - A dedicated polyethylene bailer will be used to develop each well. Three well volumes will be evacuated from each well prior to sampling. Step 3 - Collect water samples. Water samples will be collected using a polyethylene bailer. Step 4 - Store samples in a cooler on ice for transport to the laboratory. Follow all documentation and chain - of -custody procedures. Step 5 - Clean equipment. Water level measurement equipment will be cleaned with ethanol followed by a deionized water rinse. Upon completion of soil or groundwater sampling, a chain of custody log will be initiated. A copy of the chain of custody will be returned to the project manager. Chemical Analysis All analytical parameters are presented on Table 1. Groundwater Elevation Measurements The following outlines our standard groundwater quality sampling methodology. Before purging any of the soil test borings or monitoring wells, water level measurements must be taken. Measuring Point Establish the measuring point for the well. The measuring point is marked on the north side of the top of the monitoring well riser. The top of the riser is normally a one or two inch casing inside a locked protective casing. The riser will generally be PVC pipe. The measuring point should be described on the groundwater sample collection record or field book. Access After unlocking or opening a monitoring well, the first task will be to obtain a water level measurement. Water level measurements will be made using an electronic water level indicator. Depth to water and total depth of the well will be measured for calculation of purge volume. AWES, LLC Measurement To obtain a water level measurement, lower a decontaminated electronic water level probe into the monitoring well. Care must be taken to assure that the electronic probe hangs freely in the monitoring well and is not adhering to the well casing. The electronic probe will be lowered into the well until the audible sound of the unit is detected and the light on the electronic sounder illuminates. At this time, the precise measurement should be determined by repeatedly raising and lowering the probe to obtain an exact measurement. The water level measurement is then entered on the groundwater sampling collection record sheet or field book to the nearest 0.01 feet. Decontamination The electronic probe shall be decontaminated immediately after use by wiping with isopropyl alcohol -soaked paper towels. If applicable always proceed in order from the suspected cleanest well or soil test boring to the suspected most contaminated one. Purge Volume Computation All monitoring wells will be purged prior to sample collection. Depending upon the rate of recovery, three to five volumes of groundwater present in a well or bore hole shall be withdrawn prior to sample collection. If a well or bore hole bails dry, the well or bore hole should be allowed to recharge and a sample taken as soon as there is sufficient volume for the intended analysis. The volume of water present in each well or bore hole shall be computed using the two measurable variables, length of water column in soil boring or monitoring well and diameter. Purging and Sample Collection Procedures Bailing • Obtain a laboratory decontaminated disposable bailer and a spool of nylon rope or equivalent bailer cord. Tie a bowline knot or equivalent through the bailer loop. Test the knot for adequacy by creating tension between the line and the bailer. Tie again if needed. New rope will be used for every sample or purge. New clean latex gloves will be used when touching the rope or bailer. • Spread a clean plastic sheet near the base of the well. The plastic sheet should be of sufficient size to prevent bailer or bailer rope from contacting the ground surface. • Place the bailer inside the well to verify that an adequate annulus is present between the bailer and the well casing to allow free movement of the bailer. • Lower the bailer carefully into the well casing to remove the sample from the top of the water column, taking care not to agitate the water in the well. • Pour the bailed groundwater into a bucket. Once the bucket is full, transfer the water to a barrel and contain on -site. If no regulated substances are suspected the evacuated water can be poured on the ground if local regulations allow. AWES, LLC • Raise the bailer by grasping a section of cord, using each hand alternately. This bailer lift method will assure that the bailer cord will not come into contact with the ground or other potentially contaminated surfaces. Sampling Instructions for obtaining samples for parameters are reviewed with the laboratory coordinator to insure that proper preservation and filtering requirements are met. • Appropriate sample containers will be obtained from the contract laboratory. After samples are collected, they will be put on ice in coolers (4°C). Care will be taken to prevent breakage during transportation or shipment. • Samples collected by bailing will be poured directly into sample containers from bailers. The sample should be poured slowly to minimize air entrapment into the sample bottle. During collection, bailers will not be allowed to contact the sample containers. • Upon completion of sampling a chain -of -custody log will be initiated. Chain -of -custody records will include the following information: project name and number, shipped by, shipped sampling point, location, field ID number, date, time, sample type, number of containers, analysis required and sampler's signature. The samples and chain -of -custody will be delivered to the laboratory. Upon arrival at the laboratory the samples will be checked in by the appropriate laboratory personnel. Laboratory identification numbers will be noted on the chain -of -custody record. Upon completion of the laboratory analysis, the completed chain -of -custody record will be returned to the project manager. Field Cleaning Procedures For all equipment to be reused in the field, the following cleaning procedures must be followed: • Disassemble the equipment to the extent practical. • Wash the equipment with distilled water and laboratory -grade detergent. • Rinse with distilled water until all detergent is removed. • Rinse the equipment with isopropyl or methanol, making sure all surfaces, inside and out, are rinsed. • Triple rinse the equipment with distilled water. Laboratory Selection The project manager should consider the following factors when selecting a laboratory: • Capabilities (facilities, personnel, instrumentation), including: • Participation in interlaboratory studies (e.g., EPA or other Federal or State agency sponsored analytical programs); • Certifications (e.g., Federal or State); • References (e.g. other clients); Experience. • Turnaround time; and • Technical input (e.g., recommendations on analytical procedures). AWES, LLC The project manager is encouraged to gather pertinent laboratory -selection information prior to extensively defining analytical requirements under the project. A request may be made to a laboratory to provide a qualifications package that should address the points listed above. Once the project manager has reviewed the various laboratory qualifications, further specific discussions with the laboratory or laboratories should take place. In addition, more than one laboratory should be considered. For large-scale investigations, selection of one laboratory as a primary candidate and one or two laboratories as fall -back candidates should be considered. The quality of the laboratory service provided is dependent on various factors. The project manager should be able to control the quality of the information (e.g., samples) provided to the laboratory. It is extremely important that the project manager communicate to the laboratory all the requirements relevant to the project. This includes the number of samples and their matrices, sampling schedule, parameters and constituents of interest, required analytical methodologies, detection limits, holding times, deliverables, level of QA/QC, and required turnaround of analytical results. Field and Laboratory Quality Control General Quality control checks are performed to ensure that the data collected is representative and valid data. Quality control checks are the mechanisms whereby the components of QA objectives ore monitored. Examples of items to be considered are as follows: 1. Field Activities: • Use of standardized checklists and field notebooks; • Verification of checklist information by an independent person; • Strict adherence to chain -of -custody procedures; • Calibration of field devices; • Collection of replicate samples; and • Submission of field blanks, where appropriate. 2. Analytical Activities: • Method blanks; • Laboratory control samples: • Calibration check samples; • replicate samples; • Matrix -spiked samples; • "Blind" quality control samplers; • Control charts; • Surrogate samples; • Zero and span gases; and • Reagent quality control checks. COLO RADO Department of Public Health Et Environment Dedicated to protecting and improving the health and environment of the people of Colorado CERTIFICATION TO DISCHARGE UNDER CDPS GENERAL PERMIT COG500000 DISCHARGES ASSOCIATED WITH SAND a GRAVEL MINING AND PROCESSING (and other Nonmetallic Minerals except fuel) Certification Number: COG502213 This Certification to Discharge specifically authorizes: Raptor Materials LLC to discharge from the facility identified as Two Rivers Sand, Gravel, and Reservoir Project to: South Platte River Facilit y Located at: 14822 CR 396, Milliken, Weld County, CO 80543 Center Point Latitude 40.348515, Longitude -104.74918 Outfall(s) Defined Water Discharge to Surface Outfall( Lat, Long s) Discharge Outfall(s) Description Receiving Stream MGD 001 40.343206, -104.778490 Process and commingled stockpiled extracted water from intercepted groundwater, stormwater soil /aggregate access from or South Platte River 6.4 All discharges must comply with the lawful requirements of federal agencies, municipalities, counties, drainage districts and other local agencies regarding any discharges to storm drain systems, conveyances, or other water courses under their jurisdiction. Permit Limitations and Monitoring Requirements apply to outfall 001A as outlined in the Permit in Parts I.C.1, I.D, and I.E. Crushed Stone and Construction Sand and Gravel Facilities (SIC Codes 1422) Permitted Feature ID: 001A Permitted Feature Type: External Outfall Limit Set: 2 Parameter Units Maximum Discharge Concentrations Limitations Monitoring Frequency Sample Type 30 -Day Average 7 -Day Average Daily Max. Flow, 50050 MGD 6.4 NA Re port p Instantaneous, Monthly1 In-situ1 pH, Maximum) 00400 (Minimum - s.u. NA NA 6.5-9.0 2x/month Grab Total Suspended Solids, 00530 mg/l 30 45 NA 2x/month Grab Page 1 of 3 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wqcd Oil 84066 and Grease Visual NA NA NA 2x/month Visual2 Oil and 03582 Grease, m /l g NA NA 10 Contingent2 g Grab Site Specific Limitations Total 51500 Flow3, EG MG Monthly Report NA NA Instantaneous, Monthl y Calculated Total Electrical Conductivity 00094 (EC), dS/m Report NA NA Quarterly Grab Arsenic, Recoverable, 00978 Until 12/31/2026 Total ug/l l g 3.0 2x/month Grab Arsenic, Recoverable, 00978 Effective Total 1/1/2027 ug/l l g 0.02 2x/month Grab Selenium, Dissolved, 01323 Potentially ug/l 4.6 NA 18.2 2x/month Grab 1: Flow - The chronic flow limit is equal to the flow rate provided in the permit application, and will be stated on the certification. If power is not available, flow may be measured on an instantaneous basis. 2: Oil and Grease: - A visual observation of the discharge for each permitted outfall must be made 2 times per month. In the event an oil sheen or floating oil is observed, a grab sample shall be collected, analyzed, and reported on the DMR. In addition, corrective action shall be taken immediately to mitigate the discharge of oil. 3: Total Flow - Total flow is the cumulative flow of the discharge for the month in million gallons. If continuous flow monitoring is not conducted, the permittee must calculate the total flow for the month or quarter using the 30 -day average flow (measured) and the number of days the facility discharged within the month or quarter. Compliance Schedule All information and written reports required by the following compliance schedules should be directed to the Clean Water Compliance Unit for final review unless otherwise stated. All submittals must reference the Facility's Certification Number. Pursuant to the COG500000 general permit, which authorizes compliance schedules in specific circumstances, the certification requires the following compliance schedules. A. Activities to Meet Total Recoverable Arsenic Limits In order to meet arsenic final limitation, the following schedule for identifying and implementing strategies to attain arsenic limitation is included in the permit. Code Event Description Due Date 43699 Facility Evaluation Plan Submit arsenic standard needed; submit a standard a modification such OR report if that the that has changed a compliance limitation identifies request (or and to sources the the schedule the division effluent new of if to meet standard) arsenic the from to the still underlying 001 the can new standard cannot discharge meet total be attained, the recoverable new is not 06/30/2025 Page 2 of 3 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wgcd 43699 Facility Evaluation Plan Submit the a report final limitations that evaluates may be attained. and identifies strategies such that compliance with 12/31/2025 00899 Implementa tion Schedule Submit such final that date. a progress compliance report with summarizing the the final arsenic progress in implementing limitations may the be attained strategies by the 09/30/2026 CS017 Achieve Final Compliance with Discharge Limits Submit arsenic study results that limitations. show compliance has been attained with the final 12/31/2026 Certification issued: 9/27/2022 Effective: 10/01/2022 Expiration Date: 2021-12-31 The general permit CGG500000 expired 12/31/2021 and is administratively continued. This certification is also administratively continued. It will remain in effect until the general permit is renewed or other actions are taken. This certification under the permit requires that specific actions be performed at designated times. The certification holder is legally obligated to comply with all terms and conditions of the permit. Approved by Andrea Stucky - Work Group Lead Industrial Et Natural Resource Extraction Permitting Unit Permits Section Water Quality Control Division Page 3 of 3 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wgcd COLORADO Department of Public Health & Environment Dedicated to protecting and improving the health and environment of the people of Colorado Kevin Jeakins, VP Raptor Materials LLC 8120 Gage St Frederick, CO 80516 Memorandum TO: Raptor Materials LLC FROM: Emily Mortazavi, Permit Writer (720) 515-0522 DATE: 2022-09-27 RE: Certification, Colorado Discharge Permit System - Sand and Gravel Mining and Processing Fact Sheet and Information for Permit Number COG500000 Certification Number: COG502213 Permittee-Facility: Raptor Materials LLC - Two Rivers Sand, Gravel, and Reservoir Project ATTACHMENTS: Certification COG502213 CDPS General Permit for Sand and Gravel Mining and Processing (And Other Nonmetallic Minerals Except Fuel) The Water Quality Control Division (the Division) reviewed the application materials submitted for the Two Rivers Sand, Gravel, and Reservoir Project facility (the facility) and determined that it qualifies for coverage under the CDPS General Permit for Sand and Gravel Mining and Processing (And Other Nonmetallic Minerals Except Fuel, (the general permit). The attached certification authorizes discharges under the general permit; a copy of the general permit is also attached. The certification authorizes the permittee to discharge in accordance with the conditions of the general permit, and provides site -specific monitoring requirements. The permittee is required to comply with all conditions included in the general permit as well as the certification. DISCHARGE SPECIFIC INFORMATION The discharge is to South Platte River within Segment 01 b of the Middle South Platte River Sub -basin, South Platte River Basin, found in the Classifications and Numeric Standards for the South Platte River Basin Laramie River Basin Republican River Basin Smoky Hill River Basin (Regulation No. 38) (COSPMS01b). Segment0l b is Reviewable, and is classified for the following beneficial uses: Aquatic Life, Class 1 Warm; Recreation Class E; Water Supply; and Agriculture. This facility discharges mine dewatering and commingled stormwater at Outfall 001A. The permitted flow for this facility is 6.4 MGD. Low Flow Determination To determine the low flows available to the Two Rivers Sand, Gravel, and Reservoir Project, a representative upstream gage was not available and the confluence of the Cache La Poudre River and South Platte River as well as the Big Thompson and the South Platte River occurs between the discharge location and the next downstream gage. Therefore, division subtracted Cache La Poudre flows at the USGS Gage Station 06752500 (Cache La Poudre near Greeley) (prior to confluence with the South Platte) from flows at USGS Gage Station 06754000 (South Platte River near Kersey, CO) located downstream of the facility and confluence, to determine a representative low flow at the facility. The calculated Daily flows from were obtained and the annual 30E3 low flow was calculated using U.S. Fact sheet Page 1 of 4 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wgcd Environmental Protection Agency (EPA) DFLOW software. The output from DFLOW provides calculated chronic low flows for each month. Flow data from January 1, 2011 through December 31, 2021 were available for both gage stations. These gage stations, and time frames were deemed the most accurate and representative of current flows and were therefore used in this analysis. Based on the low flow analysis described above, the upstream low flows available to the Two Rivers Sand, Gravel, and Reservoir Project discharge were calculated and are presented in the table below. Low Flows for South Platte River at the Stiles Mining Resource Low Flow (cfs) Annual Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 30E3 Chronic 137 293 293 210 155 147 137 137 137 138 221 334 347 For the purposes of determining antidegradation requirements and EC requirements, the 30E3:Design Flow dilution ratio equals 14:1 for this discharge. PROCESS WATER: BASIS FOR SITE SPECIFIC Electrical Conductivity (EC): Segment Segment 01 b of the Middle South Platte River Sub -basin, South Platte River Basin is designated for agricultural beneficial use, and has a ratio of the chronic low flow of the receiving stream to the design flow less than 100:1, in accordance with Water Quality Policy 24. An irrigation intake is located 3 miles downstream of the discharge. Therefore, the facility is required to monitor EC levels during this permit term to characterize EC in discharges from this industry. Total Arsenic: Segment 01 b of the Middle South Platte Sub -basin, South Platte basin is listed as impaired (Regulation No. 93)) for total arsenic in accordance with Section 303(d) of the federal Clean Water Act. Further, the Division has not yet developed a TMDL for total arsenic for this segment. This parameter has the potential to be in the discharge as it is may be present in groundwater dewatering discharges when natural background levels are concentrated through pumping. The standard currently has a temporary modification, and is listed as "hybrid," expiring December 31, 2024 (Regulation 38, Effective December 31, 2021). Regulation 38 specifies that for new or increased discharges that commence on or after 6/1/2013, the temporary modification adopted is As(ch) = 0.2-3.0 µg/L (Trec), expiring on 12/31/2024. This facility is considered to be a new discharge as the discharges commenced after this date, and division practice for new discharges subject to the As(ch) temporary modification is to apply the technology -based limit of 3.0 µg/L. Representative data of the discharge provided by the permittee on 9/6/2022 (2 µg/l), shows that the facility can meet the technologically based limit of 3.0 µg/L. Subsequent to the temporary modification expiration date, the limit based on the WQBEL of 0.02 µg/l for the 30 day average will take effect. Based on the sample results, the permittee may not be able to meet the final limitation of 0.02 µg/l, so a compliance schedule is included in the permit. Upon expiration of the temporary modification, the compliance schedule for total recoverable arsenic will begin. There is not sufficient data to determine an interim limit during the compliance schedule, so the effluent limit of 3 ug/L will continue during the compliance schedule. Potentially Dissolved Selenium: Selenium has the potential to be in the discharge as wastewater discharged from sand and gravel operations typically results from the pumping of groundwater that accumulates in the pits and from the washing of rock/gravel. The selenium concentration in this wastewater is influenced by local geology, groundwater hydrology, and upgradient land use. Selenium WQBELs Numeric standards are developed on a basin -specific basis and are adopted for particular stream segments by the Water Quality Control Commission. For segment COSPMS01b, the chronic water quality standard for selenium is equal to 4.6 ug/l, while the acute standard is equal to 18.2 ug/l. Fact sheet Page 2 of 4 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wgcd Determining Reasonable Potential for Selenium WQBELs The Two Rivers Sand, Gravel, and Reservoir Project has submitted selenium discharge data, and an analysis must be performed to determine whether to include WQBELs in the certification. This qualitative reasonable potential (RP) analysis is based on the Determination of the Requirement to Include Water Quality Standards - Based Limits in CDPS Permits Based on Reasonable Potential, dated December, 2002. Representative data (on -site groundwater sample since pit has not been constructed) of the discharge provided by the permittee on 9/6/2022 show potentially dissolved selenium at 6 ug/L. Therefore, there is reasonable potential for exceedance of the chronic and acute selenium standards, and limitations are included and effective upon the effective date of the certification. The permittee only submitted one data point for selenium, which is not representative of the chronic 30 -day average limitation. The permittee has not provided additional data to determine a 30 -day average value for selenium. Additionally, the division notes that a groundwater sample was collected as the pit has not yet been constructed. As such, this is not inconsistent with the prohibitions at 61.8(1). ANTIDEGRADATION REVIEW Consistent with the COG500000 fact sheet, AD limitations will not be calculated for facilities discharging to segments that are impaired for a pollutant of concern. FEE INFORMATION The Annual Fee for this certification is $435 (category 07, Subcategory V -A- Sand and gravel with process discharge and stormwater, per CRS 25-8-502). Do Not Pay This Now. Annual fees are sent to the legal or billing contact in July. The initial invoice will be sent to the legal contact shortly. GENERAL INFORMATION • Changes to the certification: Any changes that need to be made to the certification page - changes in sampling location, monitoring requirements, etc., must be submitted using the "Permit and Certification Modification form" available on the Division's website, www.coloradowaterpermits.com, and signed by the legal contact. • Monitoring and requirements: Monitoring must occur at the frequency established in the permit certification. Weather conditions may not always allow the permittee to collect a sample during business hours; however, the monitoring frequency established in the permit certification must be met. For facilities required to conduct chemical monitoring, the Division strongly recommends that the permittee contact a lab prior to setting up a sampling program. Process water sampling shall occur at a point after treatment, or after the implementation of any control measures. If control measures or treatment are not implemented, sampling shall occur where the discharge leaves control of the permittee, and prior to entering the receiving stream. Samples must be representative of what is entering the receiving stream. • Discharge Monitoring Reports (DMRs): DMRs will be mailed or emailed approximately one month following certification issuance. DMRs must be submitted quarterly as long as the certification is in effect. If the permittee, using an approved analytical method, monitors any parameter more frequently than required by this permit, then the results of such monitoring shall be included in the calculation and reporting of the values required in the DMRs form. If DMR forms have not been received prior to the end of the first quarter following issuance of the certification, please contact the Division at 303-692-3517. The division now has the ability to allow facilities to submit their DMRs electronically. Monitoring results shall be summarized for each quarter via the division's NetDMR service unless a waiver is granted in compliance with 40 CFR 127. If a waiver is granted, monitoring results shall be reported on division approved discharge monitoring report (DMR) forms (EPA form 3320-1). For more information, please call the NetDMR team at 303-691-4046 or visit www.colorado.gov/cdphe/e-reporting-rule-discharge-monitoring- report-information. • Termination requirements: The permittee may initiate termination of permit coverage by submitting a "CDPS Permits and Authorization Termination Form." To terminate the permit, the permittee must meet all termination requirements as stated in the general permit (Part I.A.7). This form is available on the Division's web site (www.coloradowaterpermits.com) and must be signed by the legal contact. Fact sheet Page 3 of 4 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wgcd CHEMICALS The permittee did not specify any chemicals for use in waters that may be discharged from the facility. On this basis, no chemicals are approved under this permit certification. Discharges with chemical addition (including, but not limited to chemical additions at any point in the treatment process, release agents, etc.), are eligible for coverage under this permit only if the Division approves the use of the specific chemical(s) and provides notification of such approval to the permittee. To request Division approval, the permit applicant must submit a modification request that includes a list of proposed chemicals, the purpose of the use, dosage rates, and the most current Material Safety Data Sheet (MSDS) for each chemical. In granting the use of such chemicals, the Division may impose additional limitations and monitoring requirements in the permit certification. Until approved, use of any chemical in waters that may be discharged could result in a discharge of pollutants not authorized under the permit. COMPLIANCE SCHEDULES Pursuant to the COG500000 general permit, which authorizes compliance schedules in specific circumstances, the certification requires the following compliance schedules for total recoverable arsenic. See the certification for more information. A compliance schedule has been included in the permit for total recoverable arsenic at outfall 001. The compliance schedule allows the permittee time to collect the necessary data to identify sources of arsenic to the discharge and identify and implement strategies to control these sources or treatment alternatives such that compliance with the final limitations may be attained. For arsenic, two years subsequent to the end of the temporary modification was determined to be an appropriate amount of time to control sources and implement treatment strategies. The compliance schedule for total recoverable arsenic begins upon the expiration of the temporary modification. Note that if the underlying standard for arsenic changes and data indicates that a compliance schedule is no longer needed, the permittee must submit a permit modification request to remove the compliance schedule. CERTIFICATION RECORDS INFORMATION The table below provides the information contained in Division records for this certification. Any changes to the contacts listed below must be provided to the Division on a "Notice of Change of Contacts" form, and must be signed by the legal contact. This form is available on the Division's website at www.coloradowaterpermits.com. Industrial Activities: Extraction of sand, gravel and related earth SIC Code(s): 1422 products stockpiled and processed as construction mater Legal Contact (receives all legal documentation, pertaining to the permit certification, including invoice; is contacted for any questions relating to the facility; and receives DMRs as appropriate): Kevin Jeakins, VP Phone number: 303-666-6657 Raptor Materials LLC Email: kjeakins@raptormaterialsllc.com 8120 Gage St Frederick, CO 80516 Facility Contact (contacted for general inquiries regarding the facility): Tana Kersting , ENS Asst Phone number: 303-447-2084 Raptor Materials LLC Email: tkersting@raptormaterialsllc.com 8120 Gage St Frederick, CO 80516 Billing Contact (receives the invoice pertaining to the permit certification): Grace Prebarich, Billing Raptor Materials LLC 8120 Gage St Frederick, CO 80516 DMR Contact Kevin Jeakins VP Raptor Materials LLC 8120 Gage St Frederick, CO 80516 Phone number: 303-666-6657 Email: gprebarich@varracompanies.com Phone number: 303-666-6657 Email: kjeakins@raptormaterialsllc.com • DIVISION USE ONLY G3A DMRs: Regular Submission Frequency Fact sheet Page 4 of 4 4300 Cherry Creek Drive S., Denver, CO 80246-1530 P 303-692-2000 www.colorado.gov/cdphe/wgcd STATE OF COLORADO COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Water Quality Control Division CDPS GENERAL PERMIT COG500000 FOR DISCHARGES FROM SAND AND GRAVEL MINING AND PROCESSING (AND OTHER NONMETALLIC MINERALS EXCEPT FUEL) AUTHORIZATION TO DISCHARGE UNDER COLORADO DISCHARGE PERMIT SYSTEM In compliance with the provisions of the Colorado Water Quality Control Act, (25-8-101 et seq., CRS, 1973 as amended) and the Federal Water Pollution Control Act, as amended (33 U.S.C. 1251 et seq.; the "Act"), sand and gravel mining and processing operations, and facilities that mine and process other nonmetallic minerals except fuel, are authorized to discharge from authorized locations throughout the State of Colorado to specified surface waters of the State. Such discharges shall be in accordance with effluent limitations, monitoring requirements and other conditions set forth in Parts I, II, and III hereof. This permit specifically authorizes the entity identified in the certification of this permit to discharge process water and stormwater at the location(s) described in the certification of this permit, to waters of the state as identified in the certification of this permit. The applicant may demand an adjudicatory hearing within thirty (30) days of the date of issuance of the final permit determination, per the Colorado Discharge Permit System Regulations, 61.7(1). Should the applicant choose to contest any of the effluent limitations, monitoring requirements or other conditions contained herein, the applicant must comply with Section 24-4-104 CRS and the Colorado Discharge Permit System Regulations. Failure to contest any such effluent limitation, monitoring requirement, or other condition, constitutes consent to the condition by the Applicant. The authorization to discharge under this permit is in effect from the date of the certification of this permit until the expiration date identified below. This permit shall expire at midnight December 31, 2021 Issued and Signed this 13th day of October 2016 COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Janet S. Kieler Digitally signed by Janet S. Kieler DN: dc.=local, dc=dphe, ou=Divisions, ou=WQC, ou=Users, cn=Janet S. Kieler, email=janet.kieler@state.co.us Date: 2016.10.13 16:46:39 -06'00' Janet Kieler, Permits Section Manager Water Quality Control Division ISSUED AND SIGNED: October 13, 2016 EFFECTIVE DATE OF PERMIT: January 1, 2017 Administratively continued 1/1/2022 PART I Page 2 of 67 Permit No.: COG500000 TABLE OF CONTENTS PART I 5 A. COVERAGE UNDER THIS PERMIT — Process water and stormwater 5 1. Activities Covered 5 2. Limitations on Coverage 6 3. Chemical addition 7 4. Obtaining and maintaining Authorization under this permit 7 5. Transfer of permit coverage 8 6. Modifying an existing permit 8 7 Permit Termination Procedures 9 B. PERMIT COMPLIANCE — Process water and stormwater 10 1. Facilities Operation and Maintenance 10 C. EFFLUENT LIMITATIONS and MONITORING REQUIREMENTS....................10 1. Process Water Discharge Effluent Limitations 10 2. Stormwater Discharge Effluent Limitations 19 D. WHOLE EFFLUENT TOXICITY (WET) TESTING REQUIREMENTS — Process water and stormwater 21 1. WET Test Requirements 22 2. Toxicity Reopener 22 E. GENERAL MONITORING AND SAMPLING REQUIREMENTS — Process water and stormwater 22 1. Monitoring Periods and Monitored outfalls 22 2. Representative sampling and Monitoring points 22 3. Adverse Weather Conditions 23 4. Analytical requirements 23 5. Flow Measuring Device — Process water discharges 24 6. Extra monitoring 25 F. REPORTING AND RECORDKEEPING — Process water and stormwater 25 1. Routine Reporting of data — DM Rs 25 2. Additional Reporting 25 3. Records 25 4. Signatory and certification requirements 26 G. CONTROL MEASURES — Stormwater only 26 1. Installation and implementation specifications 26 2. Maintenance of Control Measures and Associated Documentation 27 H. GENERAL MONITORING REQUIREMENTS - Stormwater only .... ....... ..............o.m................... 27 1. Substantially identical outfalls 27 2. Measurable storm events and Delayed release of stormwater 27 3. Storm event information 27 4. Sample Type and Requirements 28 5. Climates with Irregular Stormwater Runoff 28 6. Monitoring for allowable non-stormwater discharges 28 7. Monitoring Exceptions for Inactive and Unstaffed Sites 28 8. Monitoring Exceptions for Completed and Finally Stabilized Areas 29 9. Revocation of Monitoring Exception 29 I. SPECIFIC MONITORING REQUIREMENTS - Stormwater only 29 1. Visual Monitoring 29 2. Benchmark Monitoring 30 3. Water Quality Standards Monitoring 31 4. Additional Monitoring Required by the Division 31 J. FACILITY INSPECTIONS - Stormwateronly......®..........g.a..®®.g.4..®..g....®..........g.4..®®.g.4....a.....................®..g.4..®..g....®.............32 1. Inspection frequency and personnel 32 2. Inspection scope 32 3. Inspection documentation 32 4. Inspection frequency exceptions for Inactive and Unstaffed Sites 33 5. Runoff event inspection exception at Completed and Finally Stabilized Areas 33 6 Non-compliance discovered during inspection 34 K. CORRECTIVE ACTIONS - Stormwater only 34 1. Conditions that must be eliminated...................................................................................................................................34 PART I Page 3 of 67 Permit No.: COGS00000 2. Condition requiring review and modification 34 3. Corrective action reports and deadlines 34 4. Control measure modification 35 5 Substantially identical outfalls 35 L. GENERAL SWMP REQUIREMENTS - Stormwater only 35 1. SWMP requirement 35 2. Preparation, Submission and Implementation 35 3. Signatory Requirements 35 4. Permit Retention 35 5. SWMP Retention 35 6. Consistency with Other Plans 36 7 Required SWMP Modifications 36 M. SPECIFIC SWMP REQUIREMENTS - Stormwater only 36 1. SWMP Administrator 36 2. Facility Description 36 3. Facility Map 36 4. Facility Inventory and Assessment of Pollutant Sources 37 5. Description of Control Measures 38 6. Additional Control Measure Requirements 39 7. Inspection Procedures and Documentation 39 8. Monitoring Procedures and Documentation 39 9. Corrective Action Documentation 40 N. STORMWATER SPECIFIC REPORTING AND RECORDKEEPING - Stormwater only ...e4.n.o..a%..o..o....e'.n.o..e4.n.o..am.o..am.o40 1. Routine Reporting of data — DM Rs 40 2. Annual report 41 3. SWMP records 41 O. SECTOR -SPECIFIC REQUIREMENTS FOR ASPHALT BATCH PLANTS — Stormwater only 41 1. Asphalt batch plants 41 2. Sector -Specific Benchmarks 42 P. SECTOR -SPECIFIC REQUIREMENTS FOR CONCRETE BATCH PLANTS - Stormwater only 42 1. Concrete Batch Plants 42 2. Additional Practice -Based Effluent Limits 42 3. Additional SWMP Requirements 42 4. Sector -Specific Benchmarks 42 Q. OTHER TERMS AND CONDITIONS Stormwater only ..........................oaa0000a..00a.. .............................................. ...... .....oaooa ....... a.oao43 PARTII...........................................................0...............@.............40.. OD...... ODD..O.O ODD..... ...... ......ODD..O.OODD..O..OD..40..ODD............. ODD44 A. NOTIFICATION REQUIREMENTS..........e4......e4.n.o..a4...o..e4......e4......e4.n.o..a4...o..e4......e4......e4.n.o..a4...o..e4......e4......e4.n.o..a4...o..e......44 1. Notification to Parties 44 2. Change in Discharge 44 3. Noncompliance Notification 44 4. Transfer of Ownership or Control 45 5. Other Notification Requirements 45 6. Bypass Notification 46 7. Bypass 46 8. Upsets 46 9. Submission of Incorrect or Incomplete Information 47 B. RESPONSIBILITIES 47 1. Reduction, Loss, or Failure of Treatment Facility 47 2. Inspections and Right to Entry 47 3. Duty to Provide Information 48 4. Availability of Reports 48 5. Modification, Suspension, Revocation, or Termination of Permits By the Division 48 6. Oil and Hazardous Substance Liability 51 7. State Laws 51 8. Permit Violations 51 9. Severability 51 10. Confidentiality 51 PART I Page 4 of 67 Permit No.: COG500000 11. Fees 51 12. Duration of Permit 51 13. Section 307 Toxics 51 14. Effect of Permit Issuance 52 PART III 53 Appendix A — Description of Standard Industrial Classification (SIC) Code Major Group 14 facilities56 Appendix B — Failures/Violations of the WET Permit Limit and Automatic Compliance Response 57 Appendix C — Definitions 60 PART I Page 5 of 67 Permit No.: COG500000 PART I A. COVERAGE UNDER THIS PERMIT — Process water and stormwater 1. Activities Covered This permit authorizes the discharge of process water and stormwater runoff to surface waters of the state, from active and inactive eligible facilities engaged in mining and processing of sand and gravel (and other nonmetallic minerals, except fuel). Such facilities are described by Standard Industrial Classification (SIC) Code Major Group 14, unless a specific SIC code is made ineligible under Part I.A.2. of this permit. Appendix A provides a description of SIC Code Major Group 14 facilities. This permit also authorizes the discharge of stormwater runoff to surface waters of the state from the following non -mining activities that are located at sand and gravel facilities: asphalt batch plants (SIC code 2951), concrete batch plants (SIC Code 3273), and asphalt and concrete recycling industrial activities. This permit contains both process water and stormwater provisions, as follows: • Applicable to ALL discharges: Parts I.A, 1.8, I.13, I.E, and I.F; Part II; Part III; and all Appendices • Applicable to process water discharges, only: Part I.C.1 • Applicable to stormwater discharges, only: Part I.C.2 and Parts I.G through Q a. Eligible Process water discharges: Process water discharges from facilities that produce the commodities listed below are specifically eligible for coverage u nder this permit. • Dimension stone (SIC code 1411) • Crushed stone (SIC code 1422, 1423, 1429) • Construction sand and gravel (SIC code 1442) • Industrial sand (SIC code 1446) • Kaolin and Ball Clay (SIC code 1455) • Clay, Ceramic, and Refractory Minerals, Not Elsewhere Classified (SIC code 1459) • Graphite (SIC code 1499) The following process water discharges are eligible for coverage under this permit, unless made ineligible under Part I.A.2,: i mine dewatering, which includes: • any water, including groundwater, seepage, and stormwater (precipitation and surface runoff), that is impounded or that collects in the mine pit (surface or underground workings) and is pumped, drained, or otherwise removed from the mine through the efforts of the mine operator; • additionally, for construction sand and gravel facilities and industrial sand facilities only, wet pit overflow caused solely by direct rainfall and/or groundwater seepage. ii. process generated wastewater, which includes any wastewater used in slurry transport of mined materials, air emissions control, and processing exclusive to mining (40 CFR Part 436); iii. water used in sand and gravel processing (e.g., sorting, screening, crushing, and classifying); iv. stormwater runoff that becomes comingled with the above listed wastewaters before the discharge point. b. Eligible Stormwater discharges: Stormwater discharges from all SIC Major Group 14 facilities, and from asphalt batch plants (SIC code 2951); concrete batch plants (SIC code 3273); and asphalt and concrete recycling activities conducted at such facilities, are eligible for coverage u nder this permit. Please see Appendix C - Definitions for how the terms 'asphalt batch plant' and `asphalt concrete' are u sed in this permit. Stormwater discharges from the following areas at all SIC code Major Group 14 facilities are eligible for coverage under this permit unless made ineligible under Part I.A.2: PART I Page 6 of 67 Permit No.: COG500000 i. industrial plant yards; ii. immediate access roads and rail lines used or traveled by carriers of raw materials, manufactured products, waste material, or by-products used or created by the facility; iii. material handling sites, including those used for asphalt and concrete recycling activities, asphalt batch plants, and concrete batch plants; iv. sites used for storage and maintenance of material handling equipment; v. shipping and receiving areas; vi. manufacturing buildings, including asphalt batch plants and concrete batch plants; v. storage areas and stockpiles of raw material, intermediate products, byproducts, finished products or waste products (including topsoil, overburden, and materials associated with asphalt and concrete recycling activities, asphalt batch plants, and concrete batch plants); vii. areas where industrial activity has taken place in the past and significant materials remain and are exposed to stormwater; viii. all disturbed areas (other than those subject to the process water discharge provisions above), including mine pit out slopes; and, ix. stormwater run-on that commingles with stormwater discharges associated with sand and gravel mining and processing. c. Allowable non-stormwater discharges: The following non-stormwater discharges, as applicable to a facility, are authorized by this permit provided that appropriate control measures are implemented to minimize erosion and sediment transport resulting from such discharges, and the non-stormwater component(s) of the discharge and the control measure(s) used are identified in the Stormwater Management Plan (SWMP): i. Uncontaminated condensate (external atmospheric condensation, only) from air conditioners, coolers, and other compressors and from the outside storage of refrigerated gases or liquids; ii. Landscape (including reclamation activities) watering provided all pesticides, herbicides, and fertilizer have been applied in accordance with the approved labeling; iii. Incidental windblown mist from cooling towers that collects on rooftops or adjacent portions of the facility, but not intentional discharges from the cooling tower (e.g., "piped" cooling tower blow down or drains); and iv. Process water discharges as characterized in Part I.A.1.a above. 2. Limitations on Coverage This permit does not authorize the discharges or activities listed below. Permittees may seek individual or alternate general permit coverage for such discharges, as appropriate and available. a. Stormwater discharges associated with construction activity that disturbs one acre or more; b. Process water discharges from asphalt batch plants (resulting from the production of asphalt concrete); c. Process water discharges from concrete batch plants, including drum and truck wash water; d. Stormwater and process water discharges from placer mining industrial activities (SIC Major Group 10); e. Discharges to receiving waters designated as "outstanding waters" in accordance with 5 CCR 1002-31 (Regulation 31 - The Basic Standards and Methodologies For Surface Water); f. Discharges that are currently covered under an individual permit or an alternative general permit; g. Discharges of non-stormwater, except those authorized non-stormwater discharges listed in Part I.A.1.c; h. Discharges currently covered by a Division Low Risk Guidance Document; i. Process water discharges solely to ground water if such discharges are subject to direct regulation by the EPA or by implementing agencies under Section 25-8-202(7) of the Water Quality Control Act or Senate Bill 181 (including the Division of Reclamation, Mining and Safety). This exclusion does not apply to discharges to groundwater that have a hydrologic connection to surface waters and for which the Division determines the surface waters requirements of Regulations 31 through 39, and 61 apply; PART I Page 7 of 67 Permit No.: COG500000 J Process water discharges from operations that produce the following commodities (SIC Code in parentheses): • Gypsum (1499); • Asphaltic minerals (1499); • Asbestos and wollastonite (1499); • Barite (1479); • Fluorspar (1479); • Salines from brine lakes (2899); • Borox (1474); • Potash (1474); • Phosphate Rock (1475); 3. Chemical addition • Sodium sulfate (1474); • Frasch sulfur (1479); • Bentonite (1459); • Magnesite (1459); • Diatomite (1499); • Jade (1499); • Novaculite (1499); and • Tripoli (1499) Discharges with chemical addition (including, but not limited to chemical additions at any point in the treatment process, release agents, etc), are eligible for coverage under this permit only if the Division approves the use of the specific chemicals) and provides notification of such approval to the permittee. To request Division approval, the permit applicant must submit a list of proposed chemicals, including dosage rates, used in the treatment process. Additionally, the applicant must submit an MSDS for each chemical proposed for use. In granting the use of such chemicals, the Division may impose additional limitations and monitoring requirements in the permit certification. Chemicals used in waters that will or may be discharged to waters of the State must be used in accordance with all state and federal regulations, and in strict accordance with the manufacturer's site -specific instructions. 4. Obtaining and maintaining Authorization under this permit a. Application Requirements: To obtain authorization for discharges under this permit: i. The applicant must meet the eligibility requirements under Parts I.A.1. ii. For stormwater discharges, the applicant must develop a Stormwater Management Plan (SWMP) in accordance with the requirements of this permit prior to submitting an application to the Division, and must certify in the application that a SWMP has been completed. iii. The applicant must submit a complete, accurate, and signed permit application, on a form provided by the Division, by mail or hand delivery to the Division at least 60 days before the anticipated date of discharge; or for stormwater-only discharges, at least 60 days before the facility commences industrial activity that may result in a discharge of stormwater. The applicant must sign the application in accordance with the requirements of Part I.F (Reporting and Recordkeeping) of this permit. The complete application shall be submitted to: Colorado Department of Public Health and Environment Water Quality Control Division Permits Section, WQCD-PCP-B2 4300 Cherry Creek Drive South Denver, CO 80246-1530 iv. The applicant(s) must receive written notification that the Division granted permit coverage. b. Permit Certification Procedures: Following review of the application or other information, the Division may: i. request such additional information as is reasonably necessary to evaluate the discharge; ii. delay the authorization to discharge pending further review; iii. notify the applicant that additional terms and conditions are necessary; iv. provide a compliance schedule in the certification for terms and conditions that are new or more stringent than previous conditions; v. deny the authorization to discharge under this general permit. PART I Page 8 of 67 Permit No.: COGS00000 The Division will notify the applicant in writing of its request or determination for items i. — v. c. Alternative permits i Division required alternate permit coverage: The Division may require an applicant or permittee to apply for an individual permit or an alternative general permit if it determines the discharge does not fall under the scope of this general permit. In this case, the Division will notify the applicant or permittee that an individual or alternate permit application is required. ii. Permittee request for alternate permit coverage: A permittee authorized to discharge under this general permit may request to be excluded from coverage by applying for an individual permit. In this case, the permittee must submit an individual application, with reasons supporting the request, to the Division at least 180 days prior to any discharge. The permittee's authorization to discharge under this general permit is terminated on the effective date of the individual permit. d. Permit Expiration, and Continuation A permittee desiring continued coverage under this general permit must reapply at least 180 days in advance of the permit expiration date. The Division will determine if the permittee may continue to discharge under the terms of the general permit. An individual permit may be required for any facility not reauthorized to discharge under the reissued general permit. If this permit is not reissued or replaced prior to the expiration date, it will be administratively continued and remain in force and effect. For permittees that have applied for continued permit coverage, discharges authorized under this permit prior to the expiration date will automatically remain covered by this permit until the earliest of: i An authorization to discharge under a reissued permit, or a replacement of this permit, following the timely and appropriate submittal of a complete application requesting authorization to discharge under the new permit and compliance with the requirements of the new permit; or ii. The issuance and effect of a termination issued by the Division; or iii. The issuance or denial of an individual permit for the facility's discharges; or iv. A formal permit decision by the Division not to reissue this general permit, at which time the Division will identify a reasonable time period for covered dischargers to seek coverage under an alternative general permit or an individual permit. Coverage under this permit will cease when coverage under another permit is granted/authorized; or v. The Division has informed the permittee that discharges previously authorized under this permit are no longer covered under this permit. S. Transfer of permit coverage A permittee may transfer coverage under this general permit to a new discharger if all of the following conditions are met: a. The permittee (existing discharger) and new discharger submit a complete and accurate Notice of Transfer form, signed by the permittee and the new legal entity, to the Division at the address listed in Part I.A.4, at least 30 days prior to the proposed transfer date. The Notice of Transfer form must contain a specific date for transfer of permit responsibility, coverage, and liability b. The type of industrial activities and practices remain substantially unchanged. c. The Division does not notify the permittee of the need to submit a new application for coverage under the general permit or for an individual permit. d. The Division does not notify the permittee and new discharger of its intent to revoke coverage under the general permit. 6. Modifying an existing permit A permittee may modify an existing permit certification if all of the conditions identified below are met. PART I Page 9 of 67 Permit No.: COGS00000 Modifications include but are not limited to: adding or removing discharge outfalls, introducing new or additional chemicals to the treatment process or effluent, modifying treatment in a manner that would result in a new or altered discharge in terms of location or effluent quality, changing permit coverage from one that authorizes process water discharges (or process water and stormwater discharges), to one that authorizes stormwater discharges only because the process water discharge has been terminated, etc. Note that modifications may be subject to a fee, consistent with Part II of the permit. a. The permittee must submit a complete and accurate Modification Form, signed by the permittee, to the Division at the address listed in Part I.A.4, at least 60 days prior to implementing any requested modifications that result in a discharge to state waters. b. The permittee is not authorized to discharge under the modified conditions until the modified certification is issued and effective. 7. Permit Termination Procedures To terminate permit coverage, the permittee must submit a complete and accurate Notice of Termination form, signed by the permittee, to the Division at the address listed in Part I.A.4. The permittee's authorization to discharge under this permit terminates as notified by the Division. A Notice of Termination request that does not meet one or more of the conditions identified below is not valid. The permittee is responsible for complying with the terms of this permit until notified by the Division that the authorization is terminated. Conditions for a Notice of Termination request include: a. Termination Criteria for facilities with Division of Reclamation, Mining and Safety (DRMS) financial and performance warranties The Division may approve a Notice of Termination request when the following criteria are met for the entire sand and gravel facility: i. all permitted process water discharges authorized by this permit (as applicable to the facility), have ceased; and ii. all permitted stormwater discharges authorized by this permit have ceased because the industrial activity (including soil disturbing activities) has ceased, and no significant materials or industrial pollutants remain exposed to stormwater (i.e., all raw materials, intermediate products, byproducts, finished products and waste products have been removed or are not exposed to stormwater); and iii. the DRMS has released the permittee from further responsibility for the facility, and the permittee provides documentation with the Notice of Termination request that DRMS approved the applicable financial and performance warranty release. b. Termination Criteria for facilities without DRMS financial and performance warranties The Division may approve a Notice of Termination request when the following criteria are met for the entire sand and gravel facility: i. all permitted process water discharges authorized by this permit (as applicable to the facility), have ceased; and ii. all permitted stormwater discharges authorized by this permit have ceased because the industrial activity (including soil disturbing activities) has ceased, and no significant materials or industrial pollutants remain exposed to stormwater (i.e., all raw materials, intermediate products, byproducts, finished products and waste products have been removed or are not exposed to stormwater); and iii. the site has attained final stabilization, with little evidence of soil erosion or other runoff problem, as follows: a) a uniform, perennial vegetative cover has been established with a plant density of at least 70 percent of pre -disturbance levels, or equivalent permanent, physical erosion reduction methods have been employed; b) all alternatives to vegetation must be permanent, must stabilize all disturbed areas, and all stabilization control measures must be selected, installed, and implemented following good engineering, hydrologic, and pollution control practices adequate to prevent pollution or degradation of State waters; PART I Page 10 of 67 Permit No.: COG500000 iv. the permittee provides documentation with the Notice of Termination request that the above conditions for termination have been met for the facility, and includes photographic documentation of final stabilization conditions. c. The permittee has obtained authorization under an individual or alternative general permit for all facility discharges. d. No Exposure Certification. If the facility authorized to discharge stormwater-only under this permit becomes eligible for a no exposure exclusion from permitting under 5 CCR 1002-61.3(2)(h), the permittee may submit a complete and accurate No Exposure Certification to the Division at the address listed in Part I.A.4. The Division will terminate permit coverage using information provided in the No Exposure Certification form; the permittee does not need to submit a Notice of Termination. The Division may, after consultation with the permittee and upon good cause, revise the vegetative cover requirements on a case -by -case basis. B. PERMIT COMPLIANCE — Process water and stormwater A permittee must comply with all the terms and conditions of this permit. Violation of the terms and conditions specified in this permit may be subject to civil and criminal liability pursuant to sections 25-8-601 through 612, C.R.S.. Correcting a permit violation does not remove the original violation. Failure to take any required corrective actions, as detailed in Part IX (Corrective Actions), constitutes an independent, additional violation of this permit and may be subject to civil and criminal liability. However, where corrective action is triggered by an event that does not itself constitute permit noncompliance, such as an exceedance of an applicable benchmark, there is no permit violation unless the permittee fails to take the required corrective action within the relevant deadlines. 1. Facilities Operation and Maintenance The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control which are installed or used by the permittee as necessary to achieve compliance with the conditions of this permit. Proper operation and maintenance also includes effective performance, and adequate laboratory and process controls, including appropriate quality assurance procedures. This provision requires the operation of back-up or auxiliary facilities or similar systems when installed by the permittee only when necessary to achieve compliance with the conditions of the permit. Any sludge produced at the wastewater treatment facility shall be disposed of in accordance with State and Federal guidelines and regulations. The permittee shall take all reasonable steps to minimize or prevent any discharge of sludge use or disposal in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. As necessary, accelerated or additional monitoring to determine the nature and impact of the noncomplying discharge is required. C. EFFLUENT LIMITATIONS and MONITORING REQUIREMENTS In accordance with the Water Quality Control Commission Regulations for Effluent Limitations, Section 62.5; the Colorado Discharge Permit System Regulations, Section 61.8(2), 5 C.C.R. 1002-61; and the effluent limitation guidelines found 40 CFR Part 436 (Mineral Mining and Processing Point Source Category), the permitted discharge shall not contain effluent parameter concentrations that exceed the effluent limitations identified in this Part, and specified in the permit certification. 1. Process Water Discharge Effluent Limitations The permittee shall monitor the effluent consistent with the requirements identified in Tables C.1.1 through C.1.6 and specified in the permit certification, as applicable to the permitted feature. "Report Only" monitoring requirements for additional site -specific parameters may be included in the permit certification to obtain additional effluent quality data. The permittee must conduct all required monitoring and reporting consistent with Parts I.E and I.F of this permit, unless otherwise noted. PART I Page 11 of 67 Permit No.: COG500000 a. Dimension Stone facilities (SIC code 1411) Table C.1.1— Applicable Limitations ICIS Code 50050 00400 84066 03582 00530 51500 1 51500 EG 70295 00665 00665 00665 01323 01323 00094 Various Various Parameter Flow, MGD1 pH, s.u. O il and Grease, mg/I O il and Grease, mg/I Total Suspended Solids, mg/I Flow, Total, MG4 Flow, Total, MG4 Total Dissolved Solids, mg/I' Total Phosphorus (as P), mg/I6 Total Phosphorus (as P), Ib/month6 Total Phosphorous, cumulative lbs/previous 12 consecutive months Selenium, Potentially Dissolved, µg/I Selenium, Potentially Dissolved, lbs/day7 Electrical Conductivity (EC), dS/m Other Pollutants of Concern Whole Effluent Toxicity (WET) Limitations Monitoring Frequency 30 day average Limit in cert. al MI al a 30 Report Quarterly Total Report Monthly Total Report Various Various Various Various Various Various Various 7 day average Daily Max. 2 year average Minor Facilities General Permit Requirements a VIM a MS 45 Report 6.5-9.0 10 a al a la Site Specific Requirements IS a a MN Various a MIND a Oa a MIND a Mg Various Various Various alakaa Various IS a a al IMP a a Mil Various Various Monthly (Continuous or Instantaneous2) 2x/month 2x/month Contingent 2x/month Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various 2x/month 2x/month Quarterly Various Major Facilities 2x/month (Continuous or Instantaneous2) Weekly Weekly Weekly Weekly Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various Weekly Weekly Quarterly Various Sample Type Recorder or In -situ Grab Visual3 Grab3 Grab Calculated Calculated Grab Composite Calculated Calculated Grab Calculated Grab Grab or Composite Chronic Stat Diff and IC25≥IWC Acute LC50>100% Quarterly Quarterly 3 Composites/ Test Grab N ote 1: Flow Limit — The chronic flow limit is equal to the flow rate provided in the permit application, and will be stated in the certification. N ote 2: Flow Measurement — If power is not available, flow may be measured on an instantaneous basis. N ote 3: Oil and Grease: — A visual observation of the discharge for each permitted outfall must be made 2 times per month or weekly, as stated in the certification. In the event an oil sheen or floating oil is observed, a grab sample shall be collected weekly, analyzed, and reported on the DMR. In addition, corrective action shall be taken immediately to mitigate the discharge of oil. PART I Page 12 of 67 Permit No.: COGS00000 N ote 4: Total Flow — Total flow is the cumulative flow of the discharge for the quarter or month in million gallons. If continuous flow monitoring is not conducted, the permittee must calculate the total flow for the month or quarter using the 30 -day average flow (measured) and the number of days the facility discharged within the month or quarter. N ote 5: Total Dissolved Solids (TDS— Analysis for salinity, measured as TDS, and a requirement to report quarterly total flow will be included in the permit certification for all discharges to the Colorado River Basin. N ote 6: Total Phosphorus — Analysis for Total Phosphorus, as P, will be included in the permit certification for all discharges to waters with a control regulation for P. Monitoring requirements and effluent limitations vary depending on the applicable control regulation (Regulations 71 through 74). N ote 7: Selenium Loading Calculation -- To determine selenium loading values, use the calculation formula below: Loading in lbs/day = (30 day average effluent flow in MGD x 30 day average selenium concentration in mg/I) x 8.34 1000 ug/I = 1 mg/I PART I Page 13 of 67 Permit No.: COG500000 b. Crushed Stone, and Construction Sand and Gravel (SIC codes 1422, 1423, 1429, 1442) Table C.1.2 — Applicable Limitations ICIS Code 50050 00400 84066 03582 00530 51500 1 51500 EG 70295 00665 00665 00665 01323 01323 00094 Various Various Parameter Flow, MGD1 pH, s.u. Oil and Grease, mg/I Oil and Grease, mg/I Total Suspended Solids, mg/I Flow, Total, MG4 Flow, Total, MG4 Total Dissolved Solids, mg/I' Total Phosphorus (as P), mg/I6 Total Phosphorus (as P), Ib/month6 Total Phosphorous, cumulative lbs/previous 12 consecutive months Selenium, Potentially Dissolved, µg/I Selenium, Potentially Dissolved, lbs/day7 Electrical Conductivity (EC), dS/m Other Pollutants of Concern Whole Effluent Toxicity (WET) Limitations Monitoring Frequency 30 day average Limit in cert. a Ma a MN 30 Report Quarterly Total Report Monthly Total Report Various Various Various Various Various Various Various 7 day Daily 2 year average Max. average General Permit Requirements Report 6.5-9.0 10 45 a OM la a Site Specific Requirements Various Various Various Various Ma Various Various Various Minor Facilities Monthly (Continuous or Instantaneous2) 2x/month 2x/month Contingent 2x/month Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various 2x/month 2x/month Quarterly Various Major Facilities 2x/month (Continuous or Instantaneous2) Weekly Weekly Weekly Weekly Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various Weekly Weekly Quarterly Various Sample Type Recorder/ In -situ Grab Visual3 Grab3 b3 Grab Calculated Calculated Grab Composite Calculated Calculated Grab Calculated Grab Grab or Composite Chronic Stat Diff and IC25≥IWC Acute LC50>100% Quarterly Quarterly 3 Composites/ Test Grab Notes 1-7 are located with Table C.1.1 PART I Page 14 of 67 Permit No.: COG500000 c. Industrial Sand (SIC code 1446) Table C.1.3 — Applicable Limitations for mine dewatering; and process -generated wastewater from facilities that DO NOT use HF Flotation ICIS Code 50050 00400 84066 03582 00530 51500 1 51500 EG 70295 00665 00665 00665 01323 01323 00094 Various Various Parameter Flow, MGD1 pH, s.u. Oil and Grease, mg/I Oil and Grease, mg/I Total Suspended Solids, mg/I8 Flow, Total, MG4 Flow, Total, MG4 Total Dissolved Solids, mg/I5 Total Phosphorus (as P), mg/I6 Total Phosphorus (as P), lb/month6 Total Phosphorous, cumulative lbs/previous 12 consecutive months Selenium, Potentially Dissolved, µg/I Selenium, Potentially Dissolved, Ibs/day' Electrical Conductivity (EC), dS/m Other Pollutants of Concern Whole Effluent Toxicity (WET) Limitations Monitoring Frequency 30 day average Limit in cert. 25 7 day Daily 2 year average Max. average General Permit Requirements Minor Facilities Monthly Report (Continuous or Instantaneous2) 6.5-9.0 2x/month 2x/month 10 ---- Contingent Federal Effluent Limitation Guidelines Report Quarterly Total Report Monthly Total Report Various Various Various Various Various Various Various Me a a al 45 Site Specific Requirements a a la INS Various On MI a a a On a Ina Various Various Various Various NM a a Ma Various Various 2x/month Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various 2x/month 2x/month Quarterly Various Major Facilities 2x/month (Continuous or Instantaneous2) Weekly Weekly Weekly Weekly Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various Weekly Weekly Quarterly Various Sample Type Recorder/ In -situ Grab Visual3 Grab' Grab Calculated Calculated Grab Composite Calculated Calculated Grab Calculated Grab Grab or Composite Chronic Stat Diff and IC25≥IWC Acute LC50>100% Quarterly Quarterly 3 Composites/ Test Grab Notes 1-7 are located with Table C.1.1 Note 8: Precipitation Event Relief: As specified by the ELG, any overflow from facilities subject to Subpart D — Industrial Sand shall not be subject to the limitations for total suspended solids if the facility is designed, constructed, and maintained to contain or treat the volume of waste water which would result from a 10 -year, 24 -hour precipitation event. PART I Page 15 of 67 Permit No.: COG500000 c. Industrial Sand (SIC code 1446) (continued) Table C.1.4 — Applicable Limitations for process -generated wastewater from facilities that use HF Flotation ICIS Code 50050 00400 84066 03582 00951 51412 00951 51500 1 51500 EG 70295 00665 00665 00665 01323 01323 00094 Parameter Flow, MGD1 pH, s.u. Oil and Grease, mg/I Oil and Grease, mg/I Total Fluoride, mg/I9 Total Suspended Solids, lbs/1000 lbs production$ Total Fluoride, lbs/1000 lbs production' Flow, Total, MG4 Flow, Total, MG4 Total Dissolved Solids, mg/I5 Total Phosphorus (as P), mg/I6 Total Phosphorus (as P), lb/month6 Total Phosphorous, cumulative lbs/previous 12 consecutive months Selenium, Potentially Dissolved, µg/I Selenium, Potentially Dissolved, lbs/day7 Electrical Conductivity (EC), dS/m Limitations Monitoring Frequency 30 day average Limit in cert. MO a a MO 0.023 lbs per 1,000 Ibs total product 0.003 lbs per 1,000 lbs total product 7 day Daily Max. 2 year average average General Permit Requirements al a a la al a a la al a a la Report 6.5-9.0 10 2.0 Minor Facilities Monthly (Continuous or Instantaneous2) 2x/month 2x/month Federal Effluent Limitation Guidelines Report Quarterly Total Report Monthly Total Report Various Various Various Various Various Various 0.046 lbs per 1,000 lbs total product 0.006 lbs per 1,000 lbs total product Site Specific Requirements __ MM. OM a a VIII Various MS a a Si Various Various Various OM a a MPS Various Contingent 2x/month 2x/month 2x/month Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various 2x/month 2x/month Quarterly Major Facilities 2x/month (Continuous or Instantaneous2) Weekly Weekly Weekly 2x/month 2x/month 2x/month Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various Weekly Weekly Quarterly Sample Type Recorder/ In -situ Grab ViSual3 Grab' Grab Calculated Calculated Calculated Calculated Grab Composite Calculated Calculated Grab Calculated Grab PART I Page 16 of 67 Permit No.: COG500000 Various Various Other Concern Whole Pollutants Effluent Toxicity of Various (WET) ---- Various Various Various Various Grab Composite or Chronic Stat Diff and IC259IWC ---- Quarterly Quarterly Composites/ Test 3 Acute LC50>100% ---- Grab Notes 1-7 are located with Table C.1.1 Note 8: Precipitation Event Relief: As specified by the ELG, any overflow from facilities subject to Subpart D — Industrial Sand shall not be subject to the limitations for total suspended solids if the facility is designed, constructed, and maintained to contain or treat the volume of waste water which would result from a 10 -year, 24 -hour precipitation event. Note 9: Fluoride Water Quality Standard Based Effluent Limitation: The acute water quality based standard limitation of 2.0 mg/I for fluoride applies only on segments that are designated for domestic water supply use. PART I Page 17 of 67 Permit No.: COG500000 d. Kaolin; Ball Clay; and Clay, Ceramic, and Refractory Minerals, Not Elsewhere Classified, Excluding Bentonite and Magnesite (SIC codes 1455 and 1459) Table C.1.5 — Applicable Limitations ICIS Code 50050 00400 84066 03582 00530 51500 1 51500 EG 70295 00665 00665 00665 01323 01323 00094 Various Various Parameter Flow, MGD1 pH, s.u. Oil and Grease, mg/I Oil and Grease, mg/I Total Suspended Solids, mg/I Flow, Total, MG4 Flow, Total, MG4 Total Dissolved Solids, mg/I5 Total Phosphorus (as P), mg/I6 Total Phosphorus (as P), lb/month6 Total Phosphorous, cumulative Ibs/previous 12 consecutive months Selenium, Potentially Dissolved, µg/I Selenium, Potentially Dissolved, Ibs/day' Electrical Conductivity (EC), dS/m Other Pollutants of Concern Whole Effluent Toxicity (WET) Limitations Monitoring Frequency 30 day average Limit in cert. a la Mb IMINI 30 Report Quarterly Total Report Monthly Total Report Various Various Various Various Various Various Various 7 day Daily 2 year average Max. average General Permit Requirements 45 Report 6.5-9.0 10 la a all a al a a la a NM a Ma all a a Ma Site Specific Requirements Various la a SIM VIII all. a a PPM Various all a a NM a NM al a Various Various Various a Ma a all a Ma a all al a Mb a Various Various Minor Facilities Monthly (Continuous or Instantaneous2) 2x/month 2x/month Contingent 2x/month Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various 2x/month 2x/month Quarterly Various Major Facilities 2x/month (Continuous or Instantaneous2) Weekly Weekly Weekly Weekly Continuous or Instantaneous2 Continuous or Instantaneous2 Quarterly Various Various Various Weekly Weekly Quarterly Various Sample Type Recorder/ In -situ Grab Visual3 Grab3 Grab Calculated Calculated Grab Composite Calculated Calculated Grab Calculated Grab Grab or Composite Chronic Stat Diff and IC25≥IWC Acute LC50>100% Quarterly Quarterly 3 Composites/ Test Grab Notes 1-7 are located with Table C.1.1 PART I Page 18 of 67 Permit No.: COG500000 e. Graphite Mining (SIC code 1499) Table C.1.6 — Applicable Limitations ICIS Code 50050 00400 84066 03582 00530 74010 51500 1 51500 EG 70295 00665 00665 00665 01323 01323 00094 Various Various Parameter Flow, MGD1 pH, sw. O il and Grease, mg/I O il and Grease, mg/I Total Suspended Solids, mg/I Total Iron, mg/I Flow, Total, MG4 Flow, Total, MG4 Total Dissolved Solids, mg/I5 Total Phosphorus (as P), mg/I6 Total Phosphorus (as P), lb/month6 Total Phosphorous, cumulative lbs/previous 12 consecutive months Selenium, Potentially Dissolved, µg/I Selenium, Potentially Dissolved, Ibs/day' Electrical Conductivity (EC), dS/m Other Pollutants of Concern Whole Effluent Toxicity (WET) Limitations Monitoring Frequency 30 day average Limit in cert. a Ma a Ma ann. aa 10 1 7 day Daily 2 year average Max. average General Permit Requirements Ma a OM a anaaa Monthly Report (Continuous or Instantaneous') 6.5-9.0 2x/month 2x/month 10 ---- Contingent Federal Effluent Limitation Guidelines Report Quarterly Total Report Monthly Total Report Various Various Various Various Various Various Various NM a la a Minor Facilities 20 2 al a a MI Site Specific Requirements a a al Mb Various a a al Mb a a al Mb a a al Mb Various Various Various lean Various Various Various 2x/month 2x/month Continuous or Instantaneous' Continuous or Instantaneous' Quarterly Various Various Various 2x/month 2x/month Quarterly Various Major Facilities 2x/month (Continuous or Instantaneous') Weekly Weekly Weekly Weekly Weekly Continuous or Instantaneous' Continuous or Instantaneous2 Quarterly Various Various Various Weekly Weekly Quarterly Various Sample Type Recorder/ In -situ Grab Visual3 Grab3 Grab Grab Calculated Calculated Grab Composite Calculated Calculated Grab Calculated Grab Grab or Composite Chronic Stat Diff and IC259IWC Acute LC50>100% Quarterly Quarterly 3 Composites/ Test Grab N otes 1-7 are located with Table C.1.1 N ote 8: As specified by the ELG, for facilities subject to Subpart AL — Graphite, only that volume of water resulting from precipitation that exceeds the maximum safe surge capacity of a process waste water impoundment may be discharged from that impoundment. The height difference between the maximum safe surge capacity level and the normal operating level must be greater than the inches of rain representing the 10 -year, 24 -hour rainfall event as established by PART I Page 19 of 67 Permit No.: COGS00000 the National Climatic Center, National Oceanic and Atmospheric Administration for the locality in which such impoundment is located. 2. Stormwater Discharge Effluent Limitations a. Practice Based Effluent Limitations i. Minimize exposure The permittee must minimize the exposure of pollutant sources associated with manufacturing, processing, and material storage areas (including loading and unloading, storage, disposal, cleaning, maintenance, and fueling operations) to rain, snow, snowmelt, and runoff. Minimizing exposure may include locating these industrial materials and activities inside or protecting them with storm resistant coverings. ii. Good housekeeping The permittee must keep clean all areas exposed to stormwater runoff, as necessary to minimize potential sources of pollutants, using such measures as sweeping at regular intervals, keeping materials orderly and labeled, and storing materials in appropriate containers. iii. Maintenance of Control Measures The permittee must maintain all control measures (structural and non-structural) used to achieve the effluent limits required by this permit in effective operating condition. The permittee must conduct maintenance of control measures in accordance with Part.I.G (Control Measures) of this permit. iv. Spill prevention and response procedures The permittee must minimize the potential for leaks, spills and other releases that may be exposed to stormwater and develop plans for effective response to such potential spills. The permittee must at a minimum implement: a) Procedures for regularly inspecting, testing, maintaining, and repairing all industrial equipment and systems to avoid situations that may result in leaks, spills, and other releases of pollutants in stormwater discharged to receiving waters. b) Procedures for plainly labeling containers that could be susceptible to spillage or leakage to encourage proper handling and facilitate rapid response if spills or leaks occur; c) Preventative measures such as barriers between material storage and traffic areas, secondary containment provisions, or procedures for material storage and handling; • Permittees must implement control measures (secondary containment or equivalent protection) for any chemical (e.g., petroleum products, pesticides, magnesium chloride, treatment chemicals, etc.) located at the facility to contain all spills and prevent any spilled material from entering state waters. The containment system must have sufficient capacity to contain 10% of the volume of containers, or the volume of the largest container plus 10%, whichever is greater. d) Procedures for expeditiously stopping, containing, and cleaning up leaks, spills, and other releases. Employees who may cause, detect, or respond to a spill or leak must be trained in these procedures and have necessary spill response equipment available; and e) Procedures for notification of appropriate facility personnel, emergency response agencies, and regulatory agencies. Contact information must be in locations that are readily accessible and available. v. Erosion and sediment controls The permittee must stabilize exposed areas and manage runoff using structural and/or non-structural control measures to minimize onsite erosion and sedimentation, and the resulting discharge of pollutants. Among other actions taken to meet this effluent limit, flow velocity dissipation devices must be placed at discharge locations and within outfall channels where necessary to minimize erosion and/or settle out pollutants. vi. Management of runoff and Pollutant Removal The permittee must divert; infiltrate; reuse; contain; or treat stormwater runoff to remove pollutants, in a manner that minimizes pollutants in stormwater discharges from the site. PART I Page 20 of 67 Permit No.: COGS00000 vii. Salt storage piles or piles containing salt The permittee must enclose or cover storage piles of salt, or piles containing salt, used for deicing or other commercial or industrial purposes, including maintenance of paved surfaces, and implement appropriate measures to minimize exposure resulting from adding to or removing materials from the pile. Piles do not need to be enclosed or covered if stormwater runoff from the piles is not discharged or if discharges from the piles are authorized under another permit. viii. Employee Training The permittee must develop and implement a training program for employees. Training must be conducted at least annually, and must address the following, as applicable to the trainee's activities: the site -specific control measures used to achieve the effluent limits in this Part, components and goals of the SWMP, monitoring and inspection procedures, and other applicable requirements of the permit. At a minimum, the following individuals must be trained: a) Employee(s) overseeing implementation of, revising, and amending the SWMP. b) Employee(s) performing installation, inspection, maintenance, and repair of control measures. c) Employee(s) who work in areas of industrial activity subject to this permit. d) Employee(s) who conduct stormwater discharge monitoring required by Part.I.I of this permit. ix. Non stormwater discharges The permittee must eliminate non-stormwater discharges not authorized by this or any other CDPS permit, or conducted in accordance with a Division Low Risk Guidance document. x. Waste, Garbage and Floatable Debris The permittee must minimize the discharge of waste, garbage, and floatable debris from the site by keeping exposed areas free of such materials or by intercepting them before they are discharged. xi. Dust generation and vehicle tracking of industrial materials The permittee must minimize generation of dust and off -site tracking of raw, final, or waste materials. b. Water Quality Based Effluent Limitations i. Water Quality Standards Discharges authorized under this permit must be controlled as necessary to meet applicable water quality standards. The Division expects that compliance with all other terms and conditions in this permit will control discharges as necessary to meet applicable water quality standards. If at any time the permittee becomes aware, or the Division determines, that the authorized discharge causes or contributes to an exceedance of applicable water quality standards, the permittee must conduct, document, and report corrective action as required in Part I.I< (Corrective Actions). If information in the application, required reports, or from other sources indicates that compliance with the other terms and conditions of this permit will not control the discharge as necessary to meet applicable water quality standards, the Division may include a site -specific water quality -based effluent limitation in the permit certification, or require the permittee to obtain coverage under an individual permit. The Division may include a compliance schedule for any new or revised water quality -based effluent limitation included in a permit certification, as appropriate. The Division may also include additional terms and conditions in the permit certification to determine whether compliance with the remaining terms and conditions of the permit will control the discharge as necessary to meet applicable water quality standards, or to monitor compliance with a site - specific water quality -based effluent limitation. PART I Page 21 of 67 Permit No.: COG500000 ii. Additional requirements for discharge to water quality impaired waters a) Existing Discharge to an Impaired Water with an EPA Approved or Established TMDL. Where a pollutant and applicable water quality standard has been identified, the Division may apply the monitoring requirements of Part 1.1.3 in the permit certification. When the Division determines that compliance with the other terms and conditions of this permit will not control the discharge as necessary to be consistent with the assumptions and requirements of the TMDL, including any wasteload allocation for the facility, the Division may include a site -specific water quality -based effluent limitation in accordance with Part I.C.2.b.i above in the permit certification, or inform the permittee if coverage under an individual permit is necessary. The Division may also include additional terms and conditions in the permit certification to determine whether the discharge is consistent with the assumptions and requirements of the TMDL. b) Existing Discharge to an Impaired Water without an EPA Approved or Established TMDL. Where a pollutant and applicable water quality standard has been identified, the Division may apply the monitoring requirement of Part 1.1.3 in the permit certification. Note that this provision also applies to situations where the Division determines that the discharge may need to be controlled as necessary to meet water quality standards in a downstream water segment, even if the discharge is to a receiving water that is not specifically identified on a Section 303(d) list. c) New Discharge to an Impaired Water. Where a pollutant and applicable water quality standard has been identified, the Division will make a determination whether the discharge has reasonable potential to cause or contribute to an exceedance of the applicable water quality standard for the identified pollutant. Where reasonable potential is determined, the Division will include monitoring requirements of Part 1.1.3 and/or a site -specific water quality -based effluent limitation in accordance with Part I.C.2.b.i. The water quality -based effluent limitation will be narrative, and consistent with the following statement: "Discharges authorized under this permit must be controlled as necessary to meet the applicable water quality standard for [the subject pollutant] at the point of discharge (end of pipe)." iii. Additional requirements for discharges to waters designated as critical habitat for threatened and endangered species Where a pollutant and applicable water quality standard has been identified, the Division may apply the monitoring requirements of Part 1.1.3 in the permit certification. The Division may also include additional terms and conditions in the permit certification to determine whether compliance with the remaining terms and conditions of the permit will control the discharge as necessary to eliminate or minimize the potential for no more than minor detrimental effects to listed species in regards to receiving water mixing (October 2005 Memorandum of Agreement (MOA) entered into by the Division, EPA, and USFWS). iv. Additional requirements for new or increased discharges to reviewable waters If the Division determines that compliance with the other terms and conditions of this permit will not control the discharge as necessary to be consistent with the applicable antidegradation requirements, the Division may include additional terms and conditions in accordance with Part I.C.2.b.i above in the permit certification, or inform the permittee if coverage under an individual permit is necessary. D. WHOLE EFFLUENT TOXICITY (WET) TESTING REQUIREMENTS — Process water and stormwater The Division may require WET testing for discharges on a site -specific basis, to ensure that there are no discharges of pollutants "in amounts, concentrations or combinations which are harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life", as required by Section 31.11 (1) of the Basic Standards and Methodologies for Surface Waters. WET testing requirements are identified below. Appendix B identifies the test results that constitute a failure and/or violation of WET; and automatic compliance response triggers and associated required actions. PART I Page 22 of 67 Permit No.: COGS00000 1. WET Test Requirements a. Acute Testing Requirements: For facilities where acute WET testing is required, the permittee shall conduct an acute 48 -hour WET test using Ceriodaphnia dubia, and an acute 96 -hour WET test using Pimephales promelas. Acute tests shall be conducted as a static replacement test using a single effluent grab sample. The permittee shall conduct each acute WET test in accordance with the 40 CFR Part 136 methods described in Methods for Measuring the Acute Toxicity of Effluents and Receiving Water to Freshwater and Marine Organisms, Fifth Edition, October 2002 (EPA -821-R- 02-012) or its most current edition. b. Chronic Testing Requirements: For facilities where chronic WET testing is required, the permittee shall conduct the chronic WET test using Ceriodaphnia dubia and Pimephales promelas, as a static renewal 7 -day test using three separate composite samples. The permittee shall conduct each chronic WET test in accordance with the 40 CFR Part 136 methods described in Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Water to Freshwater Organisms, Fourth Edition, October 2002 (EPA -821-R-02-013) or the most current edition. For the chronic Ceriodaphnia dubia test, the termination requirement shall be where 80% or more of the surviving control females having produced their third brood. If this requirement is not met, the test is considered invalid and retesting must be performed during the monitoring period. The permittee will be required to submit documentation showing that the appropriate number of the surviving control females have had their third brood with the WET information summary that is submitted to the Division with the WET test results. c. Acute and Chronic Testing Requirements: The minimum dilution series to be used at the facility will be specified in the certification. If the permittee uses more dilutions than prescribed, and accelerated testing is to be performed, the same dilution series shall be used in the accelerated testing as was used in the failed test. All WET tests shall be done at the frequency listed in Part I.C.1. Test results shall be reported along with the Discharge Monitoring Report (DMR) submitted for the end of the reporting period when the sample was taken. (i.e., WET testing results for the calendar quarter ending March 31 shall be reported with the DMR due April 28, etc.) The permittee shall submit all laboratory statistical summary sheets, summaries of the determination of a valid, invalid or inconclusive test, and copies of the chain of custody forms, along with the DMR for the reporting period. If a test is considered invalid, the permittee is required to perform additional testing during the monitoring period to obtain a valid test result. Failure to obtain a valid test result during the monitoring period shall result in a violation of the permit for failure to monitor. 2. Toxicity Reopener This permit may be reopened and modified to include additional or modified numerical permit limitations, new or modified compliance response requirements, changes in the WET testing protocol, the addition of both acute and chronic WET requirements, or any other conditions related to the control of toxicants. E. GENERAL MONITORING AND SAMPLING REQUIREMENTS — Process water and stormwater 1. Monitoring Periods and Monitored outfalls Monitoring requirements in this permit begin in the first full month following the permit effective date. Applicable monitoring requirements apply to each outfall authorized by this permit, except as otherwise exempt from monitoring as a "substantially identical outfall" (for stormwater only - see Part I.H.1 of the permit). 2. Representative sampling and Monitoring points Samples and measurements taken for the respective identified monitoring points required in the permit certification shall be representative of the volume and nature of the wastestream and/or effluent. Monitoring points shall be so designed or modified so that a sample of the effluent can be obtained at a point after the final treatment process and prior to discharge to state waters. All samples shall be taken at the monitoring points specified in the permit certification and, when specified, before the effluent joins or is diluted by any other wastestream, body of water, or substance. Monitoring points shall not be changed without a modification request submitted to and approval by the Division. The permittee shall provide access to the PART I Page 23 of 67 Permit No.: COG500000 Division to sample at these points. Except where specified, grab samples shall be used for all monitoring and shall not be combined. 3. Adverse Weather Conditions When adverse weather conditions prevent sample collection according to the relevant monitoring schedule, the permittee must take a substitute sample, as possible, during the remaining monitoring period; for stormwater, the permittee must take a substitute sample during the next qualifying storm event. Adverse conditions are those that are dangerous or create inaccessibility for personnel, such as local flooding, high winds, or electrical storms. Adverse weather does not exempt the permittee from having to file timely DMRs. The permittee must report any failure to monitor and indicate the basis for not sampling during the usual reporting period. 4. Analytical requirements The permittee shall install, calibrate, use and maintain monitoring methods and equipment, including biological and indicated pollutant monitoring methods. All sampling shall be performed by the permittee according to specified methods in 40 C.F.R. Part 136; methods approved by EPA pursuant to 40 C.F.R. Part 136; or methods approved by the division in the absence of a method specified in or approved pursuant to 40 C.F.R. Part 136. The permittee may use an equivalent and acceptable alternative to an EPA -approved method without EPA review where the requirements of 40 CFR Part 136.6 are met and documented. The permittee may use an Alternative Test Procedure (ATP). An ATP is defined as a way in which an analyte is identified and quantified that is reviewed and approved by EPA in accordance with 40 CFR Part 136.4 for nationwide use, or a modification to a 40 CFR 136 approved method that is reviewed and approved by EPA in accordance with 40 CFR Part 136.5 for limited use. a. The permittee must select a test procedure that is "sufficiently sensitive" for all monitoring conducted in accordance with this permit. b. The PQLs for specific parameters are listed in tables E.4-1, below. c. If the permit contains an interim effluent limitation (a limit is report until such time as a numeric effluent limit becomes effective) for a parameter, the final numeric effluent limit shall be considered the AWQC for the purpose of determining whether a test method is sufficiently sensitive. d. When the analytical method which complies with the above requirements has an ML greater than the permit limit, and the permittee's analytical result is less than the ML, the permittee shall report "BDL" on the DMR. Such reports will not be considered as violations of the permit limit, as long as the method is sufficiently sensitive. For parameters that have a report only limitation, and the permittee's analytical result is less than the ML, (where X = the ML) "< X" shall be reported on the DMR. e. In the calculation of average concentrations (i.e. 7- day, 30 -day average, 2 -year rolling average) any individual analytical result that is less than the ML shall be considered to be zero for the calculation purposes. When reporting: • If all individual analytical results are less than the ML, the permittee shall report either "BDL" or "<X" (where X = the ML), following the guidance above. • If one or more individual results is greater than the ML, an average shall be calculated and reported. Note that it does not matter if the final calculated average is greater or less than the ML, it must be reported as a value. PART I Page 24 of 67 Permit No.: COG500000 Table E. 4-1. Practical Quantitation Limits (PQLs) Parameter Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Calcium Chromium Chromium, Trivalent Chromium, Hexavalent Copper Iron Lead Magnesium Manganese Mercury Mercury, Low Level Molybdenum Nickel Selenium Silver Sodium Thallium Zinc Reporting Units µg/L2 µg/L µg/L µg/ L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/L µg/ L µg/ L µg/ L µg/ L µg/ L Metals, inorganics, nutrients, radiological parameters, and nonylphenol PQL 15 2 1 1 2 20 0.5 120 20 2o314 2 203 0.5 35 2 0.23 0.002 0.5 1 13 0.5 150 0.5 10 Parameter Ammonia N itrogen N itrate+Nitrite N itrogen N itrate Nitrogen Nitrite Nitrogen Total Kjeldahl Nitrogen Total Nitrogen Total Inorganic N itrogen Phosphorus BOD/CBOD Chloride Total Residual Chlorine, DPD Total Residual Chlorine, Amperiometric Cyanide Fluoride Phenols Sulfate Sulfide Total Dissolved Solids (TDS) Total Suspended Solids (TSS) Radium -226 Radium -228 Uranium N onylphenol, ASTM D7065 Reporting Units mg/L2 N mg/L N mg/L N mg/L N mg/L N mg/L N mg/L N mg/L P mg/L mg/L mg/L mg/L µg/L mg/L µg/L mg/L mg/L H2S mg/L mg/L pCi/L pCi/L µg/ L µg/ L PQL 0.2 0.1 0.1 0.05 0.5 0.5 0.2 0.053 2 2 0.5 0.05 103 0.5 30 2 0.1 10 5 1 1 1 10 1 µg/L = micrograms per liter 2 mg/L = milligrams per liter 3 PQL established based on parameter specific evaluation 'For hexavalent chromium, samples must be unacidified so dissolved concentrations will be measured rather than potentially dissolved concentrations. 5. Flow Measuring Device - Process water discharges The permittee shall provide flow measuring and metering to give representative values of throughput and treatment of the wastewater system. The flow measuring device may be equipped with a local flow indication instrument and a flow indication- recording-totalization device suitable for providing permanent flow records. At the request of the Division, the permittee must be able to show proof of the accuracy of any flow -measuring device used in obtaining data submitted in the monitoring report. The flow -measuring device must indicate values within ten (10) percent of the actual flow discharging from the point source. PART I Page 25 of 67 Permit No.: 000500000 6. Extra monitoring lithe permittee, using an approved analytical method, monitors any parameter more frequently than required by this permit, then the results of such monitoring shall be included in the calculation and reporting of the values required in the Discharge Monitoring Report Form (DMRs) or other forms as required by the Division. Such increased frequency shall also be indicated. F. REPORTING AND RECORDKEEPING — Process water and stormwater 1. Routine Reporting of data — DMRs As directed by the Division, the permittee may be required to report the data gathered in compliance with Parts I.C on a monthly basis for those facilities subject to a WLA and associated concentration based WQBEL in the permit certification; reporting shall be a on a quarterly basis for all other facilities. Reporting of all data shall comply with the requirements of Part I.E. (General Monitoring and Sampling Requirements) and Part I.F. (Reporting and Record keeping) of this permit. Starting December 21, 2016, the permittee must electronically report DMRs by using the EPA's Net-DMR service unless a waiver is granted in compliance with 40 CFR 127. If submitted on paper, the data must be reported on Division approved discharge monitoring report (DMR) forms (EPA form 3320-1). The permittee must submit these forms by mail. The original signed copy of each discharge monitoring report (DMR) shall be submitted to the Division at the following address: Colorado Department of Public Health and Environment Water Quality Control Division WQCD-P-B2 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 For both electronic and paper reporting the data must be received no later than the 28th day of the following month (for example, the DMR for the first calendar quarter must be received by the Division by April 28th). If no discharge occurs during the reporting period, "No Discharge" shall be reported. The Discharge Monitoring Report paper and electronic forms shall be filled out accurately and completely in accordance with requirements of this permit and the instructions on the forms. They shall be signed by an authorized person as identified in Part I.F.4. 2. Additional Reporting In addition to the reporting requirements stipulated in this Part, the permittee is also subject to the standard permit reporting provisions of Part II of this permit. 3. Records a. The permittee shall establish and maintain records. Those records shall include, but not be limited to, the following: i. The date, type, exact place, and time of sampling or measurements; ii. The individual(s) who performed the sampling or measurements; iii. The date(s) the analyses were performed; iv. The individual(s) who performed the analyses; v. The analytical techniques or methods used; and vi. The results of such analyses. vii. Any other observations which may result in an impact on the quality or quantity of the discharge as indicated in 40 CFR 122.44 (i)(1)(iii). b. The permittee shall retain for a minimum of three (3) years records of all monitoring information, including all original strip chart recordings for continuous monitoring instrumentation, all calibration and maintenance records, copies of all PART I Page 26 of 67 Permit No.: COGS00000 reports required by this permit and records of all data used to complete the application for this permit. This period of retention shall be extended during the course of any unresolved litigation regarding the discharge of pollutants by the permittee or when requested by the Division or Regional Administrator. 4. Signatory and certification requirements a. All reports and other information required by the Division, shall be signed and certified for accuracy by the permittee in accord with the following criteria: i. In the case of corporations, by a responsible corporate officer. For purposes of this section, the responsible corporate officer is responsible for the overall operation of the facility from which the discharge described in the form originates; ii. In the case of a partnership, by a general partner; iii. In the case of a sole proprietorship, by the proprietor; iv. In the case of a municipal, state, or other public facility, by either a principal executive officer, or ranking elected official. For purposes of this section, a principal executive officer has responsibility for the overall operation of the facility from which the discharge originates; v. By a duly authorized representative of a person described above, only if: a) The authorization is made in writing by a person described in i, ii, iii, or iv above; b) The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity such as the position of plant manager, operator of a well or a well field, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company. (A duly authorized representative may thus be either a named individual or any individual occupying a named position); and, c) The written authorization is submitted to the Division. b. If an authorization as described in this section is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of this section must be submitted to the Division prior to or together with any reports, information, or applications to be signed by an authorized representative. The permittee, or the duly authorized representative shall make and sign the following certification on all such documents: "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is to the best of my knowledge and belief, true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." G. CONTROL MEASURES - Stormwater only All control measures used by the permittee to meet the effluent limitations contained in this permit must be selected, designed, installed, implemented, and maintained in accordance with good engineering hydrologic and pollution control practices, and the manufacturer's specifications, when applicable. The term "Minimize", for purposes of implementing control measures to meet the requirements of Part I.C.2 of this general permit, means reduce and/or eliminate to the extent achievable using control measures that are technologically available and economically practicable and achievable in light of best industry practice. 1. Installation and implementation specifications Installation and implementation specifications for each control measure type used by the permittee to meet the effluent limitations contained in this permit, must be retained with the SWMP (see Part I.M of this general permit). PART I Page 27 of 67 Permit No.: COGS00000 2. Maintenance of Control Measures and Associated Documentation a. The permittee must maintain all control measures used to achieve the effluent limits required by this permit in effective operating condition (see Part I.C.2). For this permit, maintenance includes preventative and routine maintenance, modification, repair, replacement, or installation of new control measures. Observations resulting in maintenance activities can be made during a site inspection, or during general observations of site conditions. b. Corrective actions associated with maintaining control measures must be conducted with due diligence, as soon as possible after the need is discovered, to achieve the effluent limits required by this permit. The permittee must implement interim control measures to achieve the effluent limits required by this permit while performing maintenance of the primary control measure. c. The permittee shall document corrective actions associated with maintaining control measures, in accordance with Part. I.K (Corrective Actions) of this permit, and shall revise the facility SWMP to reflect replacement or installation of new control measures. H. GENERAL MONITORING REQUIREMENTS - Stormwater only 1. Substantially identical outfalls When a facility has two or more outfalls that, based on a consideration of features (e.g. grass vs. pavement, slopes, catch basins vs. swales) and activities within the area drained by the outfall, the permittee reasonably believes discharge substantially identical effluents, the permittee may monitor the effluent of one such outfall and report that the results also apply to the substantially identical outfalls. a. For visual assessments, this provision applies only when visual assessments are rotated between each substantially identical outfall throughout the period of the permittees coverage under this permit. b. As required in Part I.M.8, the SWMP must describe the rationale for any substantially identical outfall determinations. 2. Measurable storm events and Delayed release of stormwater a. Rain event: The permittee must conduct all required monitoring on a storm event that results in an actual discharge from the facility ("measurable storm event"), which includes discharges to surface water within the facility permit boundary, and that follows the preceding measurable storm event by at least 72 hours (3 days). b. Snowmelt event: The permittee must conduct snowmelt monitoring at a time when a measurable discharge occurs from the facility, which includes discharges to surface water within the facility permit boundary occurs. c. Delayed release of stormwater: In the event stormwater is detained at the facility (such as in a detention pond/area), and discharges or is manually released at a later date, the permittee must conduct all required monitoring at the time of release, and record Storm Event information (see Part I.H.3, below) for the previous measureable storm event. This requirement pertains to those discharges that result in an actual discharge from the facility, or that discharge to surface water within the facility permit boundary. Discharges from the mining pit (process water) are not subject to this provision. 3. Storm event information a. Rain event: For each measurable storm event that is monitored to meet the requirements of the permit, the permittee must document: i The date, time of the start of the discharge, time of sampling, duration (in hours) of the rainfall event, and magnitude (in inches) of the storm event sampled; and ii. The duration between the storm event sampled and the end of the most recent storm event that produced a discharge PART I Page 28 of 67 Permit No.: 0OO500000 This documentation is required only for those storm events that result in a discharge that the permittee monitors. b. Snowmelt monitoring: The permittee must document the date of the sampling event for each monitored snowmelt event. This documentation is required only for those snowmelt events that result in a discharge that the permittee monitors. 4. Sample Type and Requirements a. Grab samples shall be used for all monitoring and shall not be combined. b. Permittees must take a minimum of one grab sample from a discharge resulting from a measurable storm event. c. Grab samples must be collected within the first 30 minutes of a measurable storm event (see Part I.H.2). If it is not possible to collect the sample within the first 30 minutes of a measurable storm event, the sample must be collected as soon as practicable after the first 30 minutes, and documentation must be kept with the SWMP explaining why it was not possible to take samples within the first 30 minutes. d. In the case of snowmelt, samples must be taken during a period with a measurable discharge. e. All discharge samples at a facility must be taken during the same storm event, if feasible. 5. Climates with Irregular Stormwater Runoff a. If a facility is located in an area where limited rainfall occurs during parts of the year, or in areas where freezing conditions exist that prevent runoff from occurring for extended periods, the permittee may submit a modification request to the Division, to change the required monitoring events to seasons when precipitation occurs, or when snowmelt results in a measurable discharge from the facility. b. The permittee must still collect the required number of samples. c. The permittee must maintain the revised monitoring schedule with the facility's SWMP as specified in Part I.M.8. 6. Monitoring for allowable non-stormwater discharges A permittee is only required to monitor allowable non-stormwater discharges (as delineated in Part I.A.1.c) when they are commingled with stormwater discharges associated with industrial activity. 7. Monitoring Exceptions for Inactive and Unstaffed Sites The requirement that permittees conduct and document visual monitoring, benchmark sampling, or water quality standards monitoring of stormwater discharges does not apply at inactive and unstaffed sites (please see Appendix C - Definitions for how the term 'inactive' is used in this permit). Routine reporting of DMR data must follow the reporting conventions required at the Stormwater Specific Reporting and Recordkeeping section (Part I.N) of the permit. Additional requirements apply to these facilities, as provided below. a. At inactive and unstaffed facilities that maintain a condition of no exposure, i.e., there are no industrial materials or activities exposed to stormwater: i. The permittee must maintain a statement in the facility SWMP (Part I.M.8) indicating that the site is inactive and unstaffed (and associated dates), and that there are no industrial materials or activities exposed to precipitation, in accordance with the substantive requirements in 5 CCR 1002-61.3(2)(h). The statement must be signed and certified in accordance with Part I.F (Reporting and Recordkeeping). ii. If conditions change and industrial materials or activities become exposed to stormwater, this exception no longer applies and instead, the exception at Part I.H.7.b, below, applies. b. At inactive and unstaffed facilities that do not maintain a condition of no exposure, the permittee must conduct additional facility inspections as required at Part I.J.4 of this permit. PART I Page 29 of 67 Permit No.: COGS00000 c. If conditions change and the facility becomes active and/or staffed, exceptions under this part no longer apply and the permittee must immediately resume quarterly visual monitoring and benchmark sampling, and applicable water quality standards sampling at the frequency identified in the permit certification. d. The presence of staff at the facility to conduct required facility inspections does not change the inactive and unstaffed status of the facility for the purposes of this part. 8. Monitoring Exceptions for Completed and Finally Stabilized Areas The requirement that permittees conduct and document visual monitoring, benchmark sampling, or water quality standards monitoring of stormwater discharges does not apply at completed facilities, completed portions of facilities, or finally stabilized portions of facilities that meet all of the following conditions: a. All industrial activities (such as mining, processing, batch plant activities, other land disturbing activities, fueling, loading/unloading etc.) are temporarily or permanently complete in the specified area, where temporarily complete means that such industrial activities are not currently conducted at the facility, but may recommence in the future; and b. The permittee has implemented all final stabilization measures (with or without seeding) to enable the specified area to attain final stabilization, or the specified area has attained final stabilization consistent with Part.I.A.7.a orb of the permit; and c. All final stabilization measures are selected, designed, installed, implemented and maintained in accordance with good engineering hydrologic and pollution control practices such that they effectively reduce pollutant potential and the potential for control measure failure for the designated area; and d. The permittee amended the SWMP to identify those areas for which this exception applies, including the date the areas met the exception conditions. Stormwater discharges from portions of facilities that are permanently stabilized (i.e., meet the termination criteria at Part I.A. 7.b of the permit, or have obtained an Acreage (or partial) Release from the DRMS for that portion of the facility) no longer require CDPS permit coverage, as the discharge no longer meets the definition of "stormwater discharges associated with industrial activity" pursuant to Regulation 61.3(2). In such cases, the permittee may request that the division reduce the facility permit boundary by the relevant portion of the facility. 9. Revocation of Monitoring Exception The division retains the authority to revoke any Monitoring Exception identified in this Part where it is determined that the discharge causes, has a reasonable potential to cause, or contributes to an instream excursion above an applicable water quality standard, including designated uses. I. SPECIFIC MONITORING REQUIREMENTS - Stormwater only 1. Visual Monitoring Once each quarter for the entire permit term, the permittee must collect a stormwater sample from each outfall (or a substantially identical outfall pursuant to Part I.H.1 above) and conduct a visual assessment of each of these samples. a. These samples should be collected in such a manner that the samples are representative of the stormwater discharge. b. The visual assessment must be made of a sample in a clean, clear glass or plastic container, and examined in a well -lit area. The permittee must visually inspect the sample for the presence of the following water quality characteristics: i. Color; ii. Odor; iii. Clarity; iv. Floating solids; v. Settled solids; PART I Page 30 of 67 Permit No.: COG500000 vi. Suspended solids; vii. Foam; viii Oil sheen; and ix. Other obvious indicators of stormwater pollution. c. Quarterly Visual Assessment Documentation. The permittee must document the visual assessment results and maintain this documentation onsite with the facility SWMP as required in Part I.M.8. The permittee is not required to submit visual assessment findings to the Division, unless specifically requested to do so. At a minimum, visual assessment documentation of the must include: i. Sample location(s); ii. Sample collection date and time, and visual assessment date and time for each sample; iii. Personnel collecting the sample and performing visual assessment, and their signatures; iv. Nature of the discharge (i.e., runoff or snowmelt); v. Results of observations of the stormwater discharge; vi. Probable sources of any observed stormwater contamination; and vii If applicable, why it was not possible to take samples within the first 30 minutes. d. Quarterly Visual Assessment Corrective Actions: If the visual assessment indicates the control measures for the facility are inadequate or are not being properly operated and maintained, the permittee must conduct corrective actions consistent with Part I.I< (Corrective Actions) of this permit. e. The permittee shall maintain visual monitoring procedures in the SWMP as required in Part I.M.B. 2. Benchmark Monitoring This permit provides pollutant benchmark concentrations that may be applicable to the discharge authorized by this permit. The benchmark concentrations are not effluent limitations; a benchmark exceedance, therefore, is not a permit violation. When the discharge exceeds an applicable benchmark concentration, the permittee must conduct corrective actions consistent Part IX (Corrective Actions) of this permit. Failure to respond to benchmark value exceedances is a violation of the permit. a. Applicability of Benchmark Monitoring The permittee shall monitor at each benchmark sampling location for each benchmark parameter(s) specified for the industrial activity in Part 1.O - Asphalt Batch Plants, and Part I.P - Concrete Batch Plants of this permit. The Division may also include a site specific benchmark in a permit certification as appropriate to ensure that compliance with the other terms and conditions of the permit will control discharges as necessary to meet water quality based effluent limitations contained in Part I.C.2.b of the permit. b. Benchmark Monitoring Schedule Benchmark monitoring must be conducted quarterly, for the first 4 full quarters of permit coverage. Exceptions to this schedule include: i) Permittees at facilities in climates with irregular stormwater runoff may request a modification of this quarterly schedule as specified in Part I.H.5 of this permit. c. Averaging monitoring values Permittees must calculate average concentrations in accordance with the requirements of Part I.E.4 of this permit. d. Benchmark Monitoring Actions — Data not exceeding benchmarks After collecting 4 benchmark samples, if the average of the monitoring values for any parameter, at a specific outfall, does not exceed the benchmark, the permittee may reduce benchmark monitoring frequency for that parameter to once -per - year, rotating through the quarterly monitoring periods. DMR reporting shall be consistent with Part I.N of this permit. PART I Page 31 of 67 Permit No.: COGS00000 e. Benchmark Monitoring Actions — Data exceeding benchmarks i) If the averaged monitoring values for any parameter, at a specific outfall, exceeds the benchmark, as described in a) through c) below, the permittee must conduct corrective action in accordance with Part I.I<—Corrective Actions of this permit. a) The average of the initial 4 quarterly sample monitoring values for any parameter exceeds the benchmark. b) If less than 4 benchmark samples have been taken, but the sum of the quarterly sample results to date is more than 4 times the benchmark level (i.e., an exceedance of the 4 quarter average is mathematically certain ), this is considered a benchmark exceedance. c) If any of the annual samples taken after the first 4 quarterly samples (i.e., samples 5 through 8), when averaged with the proceeding samples, causes an average monitoring value that exceeds the benchmark for any parameter, this is considered a benchmark exceedance. ii) Following control measure(s) modification, the permittee must continue quarterly monitoring for 4 additional quarters. For this monitoring: a) If the average of the monitoring values for any parameter does not exceed the benchmark, the permittee may monitor once -per -year as described in Part1.1.2.d, above. b) If the average of the monitoring values for any parameter still exceeds the benchmark (or if an exceedance of the benchmark by the 4 quarter average is mathematically certain prior to conducting the full 4 additional quarters of monitoring), the permittee must again conduct corrective actions consistent with Part IX (Corrective Actions) of this permit unless the Division waives the requirement for additional monitoring and corrective action. 3. Water Quality Standards Monitoring a. Applicability of water quality standards monitoring Consistent with the provisions in Part I.C.2., the Division may apply monitoring conditions (i.e., sampling parameters, sampling frequency, and sample type) in the permit certification issued to a permittee for discharges to impaired waters, discharges to waters designated as critical habitat for threatened and endangered species, and other discharges as necessary to determine if compliance with the other terms and conditions of the permit will control discharges as necessary to meet water quality standards. Monitoring conditions will be consistent with applicable water quality standard(s) for the receiving water, and as applicable, the assumptions of any available wasteload allocation in an applicable TMDL. Water quality standards monitoring is only required at a facility if specified in the certification. b. Monitoring Frequency and modification When specified in the certification, the permittee must monitor discharges once per quarter at each outfall (except substantially identical outfalls) discharging stormwater to impaired waters. c. Modifying Monitoring Requirements A permittee may request modification of the water quality standards monitoring requirements required by the permit certification if, after one year of monitoring or 4 samples, a pollutant, at a specific outfall, is not detected above the applicable, end -of -pipe water quality standard in any sample. 4. Additional Monitoring Required by the Division The Division may notify a permittee of additional discharge monitoring requirements. Any such notice will briefly state the reasons for the monitoring, locations, and monitoring parameters, frequency and period of monitoring, sample types, and reporting requirements. Such monitoring may include salinity and in -stream sampling and whole effluent toxicity testing. PART I Page 32 of 67 Permit No.: COGS00000 J. FACILITY INSPECTIONS — Stormwater only 1. Inspection frequency and personnel a. The permittee shall conduct and document visual inspections of the facility at least quarterly (i.e., once each calendar quarter). Inspections shall be conducted at least 20 days apart. b. The permittee shall conduct a minimum of one (1) of the annual quarterly inspections during a runoff event, which for a rain event means during, or within 24 hours after the end of, a measureable storm event; and for a snowmelt event, means at a time when a measurable discharge occurs from the facility. c. The permittee shall ensure that qualified personnel conduct inspections. 2. Inspection scope Each inspection shall include: a. Observations made at stormwater sampling locations and areas where stormwater associated with mining and processing is discharged off -site, to waters of the state, or to a storm sewer system that drains to waters of the state. b. Observations for the presence of floating materials, visible oil sheen, discoloration, turbidity, odor, etc. in the stormwater discharge(s). c. Observations of the condition of and around stormwater outfalls, including flow dissipation measures to prevent scouring. d. Observations for the presence of illicit discharges or other non -permitted discharges. e. A verification that the descriptions of potential pollutant sources required under this permit are accurate. f. A verification that the site map in the SWMP reflects current conditions. g. An assessment of all control measures used to comply with the effluent limits contained in this permit, noting all of the following: i. Effectiveness of control measures inspected. ii. Locations of control measures that need maintenance or repair. iii. Reason maintenance or repair is needed and a schedule for maintenance or repair. iv. Locations where additional or different control measures are needed and the rationale for the additional or different control measures. 3. Inspection documentation The permittee shall document the findings for each inspection in an inspection report or checklist, and keep the record onsite with the facility SWMP. The permittee shall ensure each inspection report documents the observations, verifications and assessments required in Part I.J.2 above, and additionally includes: a. The inspection date and time; b. Locations inspected; c. Weather information and a description of any discharges occurring at the time of the inspection; d. A statement that, in the judgment of 1) the person conducting the site inspection, and 2) the person described in Part I.F.4 (Reporting and Recordkeeping), the site is either in compliance or out of compliance with the terms and conditions of this permit, with respect to Part I.J.2 (Inspection Scope); e. A summary report and a schedule of implementation of the corrective actions that the permittee has taken or plans to take if the site inspection indicates that the site is out of compliance; f. Name, title, and signature of the person conducting site inspection; and the following statement: "I certify that this report is true, accurate, and complete, to the best of my knowledge and belief."; g. Certification and signature of the person described in Part I.F.4 (Reports and Recordkeeping), or a duly authorized representative of the facility thereof. PART I Page 33 of 67 Permit No.: COGS00000 4. Inspection frequency exceptions for Inactive and Unstaffed Sites The requirement that permittees conduct and document quarterly visual inspections of the facility, and conduct at least one (1) inspection per calendar year during a runoff event, does not apply at inactive and unstaffed sites. Instead, the following requirements apply to such facilities (see also Monitoring Exceptions for Inactive and Unstaffed Sites at Part I.H.7 of the permit): a. At inactive and unstaffed facilities that maintain a condition of no exposure, i.e., there are no industrial materials or activities exposed to stormwater: i. The permittee must conduct two site inspections annually, in the spring and fall, in accordance with the requirements of this Part. ii. The permittee must maintain a statement in the facility SWMP pursuant to Part I.M.7 indicating that the site is inactive and unstaffed (and associated dates), and that there are no industrial materials or activities exposed to precipitation, in accordance with the substantive requirements in 5 CCR 1002-61.3(2)(h). The statement must be signed and certified in accordance with Part I.F.4 (Reports and Recordkeeping). iii. If conditions change and industrial materials or activities become exposed to stormwater, this exception no longer applies and instead, the exception at Part I.J.4.b, below, applies. iv. If conditions change and the facility becomes active and/or staffed, exceptions under this part no longer apply and the permittee must immediately resume inspections as required in Parts I.J.1-3 above. b. At inactive and unstaffed facilities that DO NOT maintain a condition of no exposure, i.e., industrial materials or activities ARE exposed to stormwater: i. The permittee must conduct six site inspections annually, once every two calendar months, at least 20 days apart, in accordance with the requirements of this Part. ii. The permittee must maintain a statement in the facility SWMP pursuant to Part I.M.7 indicating that the site is inactive and unstaffed, and associated dates. The statement must be signed and certified in accordance with Part I.F.4 (Reports and Recordkeeping). iii. If conditions change and the facility becomes active and/or staffed, exceptions under this part no longer apply and the permittee must immediately resume inspections as required in Parts I.J.1-3 above. c. The presence of staff at the facility to conduct required facility inspections does not change the inactive and unstaffed status of the facility for the purposes of this part. S. Runoff event inspection exception at Completed and Finally Stabilized Areas The requirement that permittees conduct and document at least one (1) inspection per calendar year during a runoff event, does not apply at completed facilities, completed portions of facilities, or finally stabilized portions of facilities that meet all of the conditions below. Note that all other inspection provisions in this part remain applicable. a. All industrial activities (such as mining, processing, batch plant activities, other land disturbing activities, fueling, loading/unloading etc.) are temporarily or permanently complete in the specified area, where temporarily complete means that such industrial activities are not currently conducted at the facility, but may recommence in the future; and b. The permittee has implemented all final stabilization measures (with or without seeding) to enable the specified area to attain final stabilization, OR the specified area has attained final stabilization consistent with Part.I.A.7.a or b of the permit; and PART I Page 34 of 67 Permit No.: COG500000 c. All final stabilization measures are selected, designed, installed, implemented and maintained in accordance with good engineering hydrologic and pollution control practices such that they effectively reduce pollutant potential and the potential for control measure failure for the designated area; and d. The permittee amended the SWMP to identify those areas for which this exception applies, including the date the areas met the exception conditions. Stormwater discharges from portions of facilities that are permanently stabilized (i.e., meet the termination criteria at Part I.A. 7.b of the permit, or have obtained an Acreage (or partial) Release from the DRMS for that portion of the facility) no longer require CDPS permit coverage, as the discharge no longer meets the definition of " stormwater discharges associated with industrial activity" pursuant to Regulation 61.3(2). In such cases, the permittee may request that the division reduce the facility permit boundary by the relevant portion of the facility. 6. Non-compliance discovered during inspection Any corrective action required as a result of a facility inspection must be performed consistent with Part I.K (Corrective Actions) of this permit, and retained with the SWMP. K. CORRECTIVE ACTIONS — Stormwater only 1. Conditions that must be eliminated If any of the following conditions occur at the permitted facility (as identified by the permittee; the Division; or an EPA official, or local, or State entity), the permittee must review and revise the selection, design, installation, and implementation of facility control measures to ensure that the condition is eliminated and will not be repeated in the future: a. An unauthorized release or discharge (e.g., spill, leak, or discharge of non-stormwater not authorized by this or another permit) occurs; b. Facility control measures are not stringent enough for the discharge to meet applicable water quality standards; c. Modifications to the facility control measures are necessary to meet the practice -based effluent limits in this permit; or d. The permittee finds in a facility inspection that facility control measures are not properly selected, designed, installed, operated or maintained. 2. Condition requiring review and modification If any of the following conditions occur, the permittee must review the selection, design, installation, and implementation of facility control measures to determine the appropriate modifications necessary to attain the effluent limits in this permit: a. Construction or a change in design, operation, or maintenance at the facility significantly changes the nature of pollutants discharged in stormwater from the facility, or significantly increases the quantity of pollutants discharged; or b. The average of quarterly sampling results as described in Part I.l.2.e of this permit exceeds an applicable benchmark. 3. Corrective action reports and deadlines The permittee must document discovery of any condition listed in Parts I.K.1 and I.K.2 above, within 5 days as described below, submit the documentation in an annual report as required in Part I.N, and retain a copy onsite with the facility SWMP. Within five (5) days of discovery of any condition listed in Parts I.K.1 and I.K.2, the permittee must document the following information: a. Identification of the condition triggering the need for corrective action review; b. Description of the problem identified; c. Date the problem was identified; PART I Page 35 of 67 Permit No.: COG500000 d. Summary of corrective action taken or to be taken (or, for triggering events identified in Part I.K.2 where the permittee determines that corrective action is not necessary, the basis for this determination); e. Notice of whether SWMP modifications are required as a result of this discovery or corrective action; f. Date corrective action initiated; and g. Date corrective action completed or expected to be completed. 4. Control measure modification Modification of any control measure as part of the corrective action required by Parts I.K.1 and I.K.2 must be performed consistent with Part I.G (Control Measures) of this permit. 5. Substantially identical outfalls If the event triggering corrective action is associated with an outfall that represents other substantially identical outfalls, the permittee's review must assess the need for corrective action for each outfall represented by the outfall that triggered the review. Any necessary changes to control measures that affect these other outfalls must also be performed consistent with Part I.G (Control Measures) of this permit, and the permittee must implement interim or temporary controls measures during the maintenance effort. L. GENERAL SWMP REQUIREMENTS - Stormwater only The General SWMP requirements contained in this section address administrative requirements of the SWMP, as opposed to the specific SWMP content requirements provided in Part I.M of the permit. An existing permittee authorized under the previous versions of this permit shall modify the existing SWMP to comply with the requirements of this permit within 180 -days of the facility permit certification effective date. 1. SWMP requirement The permittee must develop, implement, and maintain a SWMP for each facility authorized by this permit. The SWMP shall be prepared in accordance with good engineering, hydrologic and pollution control practices (the SWMP need not be prepared by a registered engineer). The permittee must modify the SWMP to reflect current site conditions (see Part I.L.7 below). 2. Preparation, Submission and Implementation The permittee must complete a SWMP prior to submitting the permit application for authorization to discharge industrial stormwater from a facility, and submit it to the Division if requested. The permittee must implement the SWMP when the facility begins industrial activities, which includes installation of control measures. 3. Signatory Requirements The permittee must sign and certify all SWMPs in accordance with Part I.F.4 (Reporting and Recordkeeping); this requirement applies to the original SWMP prepared for the facility, and each time the permittee modifies a SWMP as required by Part I.L.7.a and b below. 4. Permit Retention The permittee must maintain a copy of this permit and the permit certification issued to the permittee with the SWMP. 5. SWMP Retention The permittee must retain a copy of the SWMP at the facility unless another location, specified by the permittee, is approved by the Division. PART I Page 36 of 67 Permit No.: COGS00000 6. Consistency with Other Plans The permittee may incorporate, by reference, applicable portions of plans prepared for other purposes at their facility. Plans or portions of plans incorporated by reference into a SWMP become enforceable requirements of this permit and must be available along with the SWMP as required in Part.I.L.5 above. 7. Required SWMP Modifications a. Division initiated Modifications i. The permittee must modify the SWMP when notified by the Division that it does not meet one or more of the requirements of this permit. Unless otherwise provided by the Division, the permittee shall have 30 days after notification to make the necessary changes to the SWMP and implement them. ii. The Division may require the permittee to submit the modified SWMP to the Division. iii. If the Division determines that the permittee's stormwater discharges do not, or may not, achieve the effluent limits required by this permit, the Division may require the permittee, within a specified time period, to develop and implement a supplemental control measure action plan, which describes additional SWMP modifications to adequately address the identified water quality concerns. b. Permittee initiated Modifications i The permittee must modify the SWMP whenever necessary to address any of the triggering conditions for corrective action in Part IX (Corrective Actions) to ensure that they do not reoccur. ii. The permittee must modify the SWMP whenever there is a change in design, construction, operation, or maintenance at the facility that significantly changes the nature of pollutants discharged in stormwater from the facility, significantly increases the quantity of pollutants discharged, or that requires the permittee to implement new or modified control measures. iii. The SWMP modifications may include a schedule for control measure design and implementation, provided that interim control measures needed to comply with the permit are documented in the SWMP and implemented during the design period. iv. The permittee must make all SWMP modifications in accordance with the corrective action deadline in Part IX (Corrective Actions). M. SPECIFIC SWMP REQUIREMENTS - Stormwater only 1. SWMP Administrator The SWMP shall identify a specific individual(s) by name or by title whose responsibilities include: SWMP development, implementation, maintenance, and modification. 2. Facility Description The facility description shall include: a. A narrative description of the industrial activities conducted at the facility; b. The total size of the facility property in acres; c. The general layout of the facility including mining areas, revegetated areas, buildings, raw material storage areas, and the flow of goods and materials through the facility. 3. Facility Map The SWMP shall include a legible site map(s), showing the entire facility, and vicinity as appropriate, identifying: PART I Page 37 of 67 Permit No.: 0O0500000 a. The boundary of the mining and processing operation. b. The location of the facility in relation to surface waters that receive industrial stormwater discharges from the facility (including the name of the surface water; if the name is not known, indicate that on the map); a separate vicinity map may be necessary to comply with this requirement. c. The location of significant impervious surfaces within the facility property boundaries, including paved areas and buildings. d. The locations of all facility stormwater conveyances including ditches, pipes, and swales. e. The locations of stormwater inlets and outfalls, with a unique identification code for each outfall (e.g., Outfall No. 001, No.002, etc), and indicating whether one or more outfalls are "substantially identical" under Part I.H (General Monitoring Requirements); and an approximate outline of the areas draining to each outfall. f. The directions of stormwater flow indicated by arrows; g. The areas where mining and processing activities are currently or have previously been conducted, where such activities are exposed to precipitation. This includes all areas of soil disturbance and reclamation/revegetation. h. The locations of all actual or potential pollutant sources (including sediment) associated with mining and processing activities, including but not limited to those identified in the Facility Inventory and Assessment of Pollutant Sources (below) and the following: i. Vehicle fueling areas; ii. Fertilizer or chemical storage areas; iii. Areas used for storage or disposal of overburden, materials, soils or wastes; iv. Areas used for mineral milling and processing; v. All access and haul roads; and vi. All asphalt or concrete batch plants, or areas used for recycling of asphalt or concrete. i The location of any and all process water discharge outfalls, including specified locations of mine dewatering operations. j. The location of all structural and applicable non-structural control measures used to meet the effluent limits required by this permit. k. The locations where significant spills or leaks identified under Part I.L.4.b have occurred. I. The locations of all stormwater monitoring points applicable to the facility (visual monitoring; benchmark monitoring, water quality -based monitoring). m. Location and description of any non-stormwater discharges authorized in Part I.A.1.c or authorized by separate permit coverage. n. Locations and sources of run-on to the facility from adjacent property that contains significant quantities of pollutants. o. The date that the facility site map was prepared and/or amended. 4. Facility Inventory and Assessment of Pollutant Sources The facility inventory and assessment shall include the following: a. Inventory of facility activities and equipment The inventory shall identify all areas (except interior areas that are not exposed to precipitation) associated with industrial activities that have been, or may potentially be, sources of pollutants, that contribute, or have the potential to contribute, any pollutants to stormwater, including but not limited to the following: i. Loading and unloading of materials, including solids and liquids. ii. Outdoor storage of materials or products, including solids and liquids. iii. Outdoor manufacturing and processing. PART I Page 38 of 67 Permit No.: COGS00000 iv. On -site dust or particulate generating processes, including dust collection devices and vents. v. On -site waste treatment, storage, or disposal, including waste ponds and solid waste management units. vi. Vehicle and equipment fueling, maintenance, and/or cleaning (includes washing). vii. Immediate access roads and rail lines used or traveled by carriers of raw materials, manufactured products, waste material, or by-products used or created by the facility. viii. Roofs or other surfaces exposed to air emissions from a manufacturing building or a process area. ix. Roofs and associated surfaces composed of galvanized materials that may be mobilized by stormwater (e.g., roofs, ducts, heating/air conditioning equipment, gutters and downspouts). b. Inventory of materials The inventory shall list materials that contribute, or have the potential to contribute, pollutants to stormwater, including but not limited to the following: i. The types of materials handled at the facility that may be exposed to precipitation or runoff and could result in stormwater pollution. ii. The types of materials handled at the facility that may leak or spill, and be exposed to precipitation or runoff and result in stormwater pollution. iii. A narrative description of any potential sources of pollutants from past activities, materials and spills that could contribute pollutants to stormwater discharges, and the corresponding outfall(s) that would be affected by such spills and leaks. The description shall include the method and location of any on -site storage or disposal; and documentation of all significant spills and leaks of oil or toxic or hazardous pollutants that occurred at exposed areas, or that drained to a stormwater conveyance, in the 3 years prior to the SWMP preparation date. c. Assessment of potential pollutant sources The assessment of potential pollutant sources shall provide a short narrative or tabulation describing the potential of a pollutant to be present in stormwater discharges for each facility activity, equipment and material identified above. The permittee shall update this narrative when data become available to verify the presence or absence of these pollutants. Potential pollutant sources include: i. Loading and unloading operations; ii. Outdoor storage of chemicals or equipment; iii. Crushing facilities or significant dust and particulate generating activities; iv. On site waste disposal practices; v. Stockpiles of overburden, raw material, intermediate products, byproducts, finished products or waste products; vi. Asphalt or concrete batch plants or areas used for recycling of asphalt or concrete; vii. Routine maintenance activities involving fertilizers, pesticides, detergents, fuels, solvents, oils, etc.; viii. Haul roads; and ix. Disturbed and revegetated areas. 5. Description of Control Measures a. The permittee shall document the location, installation date, type, and implementation specifications of each non- structural and structural control measure implemented at the facility to achieve meet the effluent limitations contained in this permit. Documentation must include those control measures implemented for stormwater run-on that commingles with any discharges covered under this permit. b. Installation and implementation specifications for each control measure used by the permittee to meet the effluent limitations contained in this permit must be retained with the SWMP. PART I Page 39 of 67 Permit No.: COGS00000 6. Additional Control Measure Requirements The permittee shall document the schedules, procedures, and evaluation results for the following subset of practice -based effluent limitations. a. Good Housekeeping (see Part I.C.2.a.ii) - A schedule for regular pickup and disposal of waste materials, along with routine inspections for leaks and conditions of drums, tanks and containers. b. Maintenance (see Part I.C.2.a.iii) - Preventative maintenance schedules for industrial equipment and systems; control measures; and any back-up practices in place should a runoff event occur while a control measure is off-line. c. Spill Prevention and Response Procedures (see Part I.C.2.a.iv) - Procedures for preventing, responding to, and reporting spills and leaks. The permittee may reference other plans (e.g., a Spill Prevention Control and Countermeasure (SPCC) plan) otherwise required by a permit for the facility, provided that a copy of the other plan is kept onsite with the SWMP, and made available for review consistent with Part I.L (SWMP-General SWMP Requirements). d. Employee Training (see Part I.C.2.a.viii) - A schedule for all types of training required by this permit, content of the training, and log of the dates on which specific employees received training. e. Non-Stormwater Discharges (see Part I.C.2.a.ix) - Documentation of the stormwater conveyance system evaluation for the presence of non-stormwater discharges not authorized in Part.I.A.1.c, and the elimination of all unauthorized discharges. Documentation of the evaluation must include: i. The date of any evaluation; ii. A description of the evaluation criteria used; iii. A list of the outfalls or onsite drainage points that were directly observed during the evaluation; iv. The different types of non-stormwater discharge(s) and source locations; and v. The action(s) taken, such as a list of control measures used to eliminate unauthorized discharge(s), if any were identified. 7. Inspection Procedures and Documentation The permittee shall document inspection procedures, and maintain such procedures and other documentation with the SWMP, as follows: a. The permittee shall document procedures for performing the facility inspections required by Part I.J (Facility Inspections) of the permit. Procedures must identify: i. Person(s) or positions of person(s) responsible for inspection; ii. Schedules for conducting inspections, including tentative schedule for facilities in climates with irregular stormwater runoff discharges; and iii. Specific items to be covered by the inspection, including inspection schedules for specific outfalls. b. The permittee shall maintain inspection documentation with the SWMP as required by Part LJ (Facility Inspections) of this permit. c. Permittees that invoke the exception to quarterly inspections for inactive and unstaffed facilities must include in the SWMP the signed and certified documentation to support this claim as required in Part I.J (Facility Inspections). 8. Monitoring Procedures and Documentation The permittee shall document monitoring procedures, and maintain such procedures and other documentation with the SWMP, as follows: a. The permittee shall document procedures for performing any applicable types of monitoring required by Part I.I (Specific Monitoring Requirements) of the permit, including: i. Visual assessment monitoring (see Part 1.1.1) PART I Page 40 of 67 Permit No.: COGS00000 ii. Benchmark monitoring (see Part I.1.2) iii. Water Quality Standards monitoring (see Part 1.1.3); and iv. Additional monitoring as required by the Division (see Part 1.1.4). b. For each type of monitoring, procedures must identify: i. Locations where samples are collected, and outfall identification by its unique identifying number; ii. Staff responsible for conducting stormwater sampling; iii. Procedures for sample collection and handling, including any deviations from sampling within the first 30 minutes of a measurable storm event; iv. For any parameters requiring analysis, the name of the parameter, the holding times and preservatives, the analytical methods used, and the laboratory quantitation levels; v. Procedures for sending samples to a laboratory, as applicable; vi. Monitoring schedules, including any deviations from the monitoring schedule for alternate monitoring periods for climates with irregular stormwater runoff (see Part I.H.5); vii. The numeric control values (benchmarks, TMDL-related requirements, or other requirements) applicable to discharges from each outfall. c. Permittees must maintain Quarterly Visual Assessment documentation (see Part1.1.1.c) with the SWMP. d. Permittees that invoke the Monitoring Exceptions for Inactive and Unstaffed Sites and for Completed and Finally Stabilized Areas, must include in the SWMP the signed and certified documentation to support this claim. e. Permittees that use the substantially identical outfall monitoring exception (Part I.H.1) must document the following in the SWMP: i. Location of each of the substantially identical outfalls, and the outfall sampled; ii. Description of the general industrial activities conducted in the drainage area of each outfall; iii. Description of the control measures implemented in the drainage area of each outfall; iv. Description of the exposed materials located in the drainage area of each outfall that are likely to be significant contributors of pollutants to stormwater discharges; v. Impervious surfaces in the drainage area that could affect the percolation of stormwater runoff into the ground (e.g., asphalt, crushed rock, grass, etc.); vi. Why the permittee expects the outfalls to discharge substantially identical effluents. 9. Corrective Action Documentation The permittee must maintain a copy of all Corrective Action reports that document corrective actions taken by the permittee consistent with Part 1.1< (Corrective Actions) of this permit, with the facility SWMP. N. STORMWATER SPECIFIC REPORTING AND RECORDKEEPING - Stormwater only 1. Routine Reporting of data — DMRs In addition to the Reporting and Recordkeeping requirements provided at Part I.F of this permit, the required DMR reporting conventions for stormwater discharges are as follows: a. If no discharge occurs during the reporting period, "No Discharge" shall be reported on the DMR. b. If the permittee's benchmark sampling frequency is reduced consistent with Part I.I.2.d of this permit (Benchmark Monitoring Actions — Data not exceeding benchmarks), the permittee must submit quarterly DMRs and indicate "Benchmark Met" in the result field on the DMR for each parameter that meets the sampling frequency reduction criteria. PART I Page 41 of 67 Permit No.: COG500000 c. If the permittee's monitoring is excepted consistent with Parts I.H.7 and I.H.8 of this permit, the permittee must submit quarterly DMRs and indicate "General Permit Exemption" in the result field on the DMR for each parameter for the period the site meets the monitoring exception criteria. 2. Annual report ICIS Code Description Due date Frequency 00308 The period permittee January shall 1 through submit an annual December report 31. to the division for the reporting February 28 Annual a. The annual report shall include: i. Name of permittee, address, phone number ii. Permit certification number iii. Facility name and physical address iv. Contact person name, title, and phone number v. Summary of inspection dates vi. Summary of visual monitoring vii. Corrective action documentation as required in Part I.J., and status of any outstanding corrective action(s). b. The signed copy of each annual report shall be submitted to the Division at the address below, and a copy maintained with the SWMP. Attn: Annual Report Colorado Department of Public Health and Environment Water Quality Control Division WQCD-P-B2 4300 Cherry Creek Drive South Denver, Colorado 80246-1530 3. SWMP records The permittee shall retain copies of the facility SWMP, including any modifications made during the term of this permit, documentation related to corrective actions taken, all reports and certifications required by this permit, monitoring data, and records of all data used to complete the application to be covered by this permit, for a period of at least 3 years from the date that coverage under this permit expires or is terminated. O. SECTOR -SPECIFIC REQUIREMENTS FOR ASPHALT BATCH PLANTS — Stormwater only The requirements of this Part apply to stormwater discharges associated with industrial activity from asphalt batch plants (SIC Code 2951) located at sand and gravel facilities, and to areas of the permittee's facility where those sector -specific activities occur. These sector -specific requirements are in addition to any requirements specified elsewhere in this permit. 1. Asphalt batch plants Asphalt batch plants (permanent and mobile) that operate at sand and gravel facilities, where the facility is permitted for such operations, may be covered by this permit. Asphalt batch plants that operate at sand and gravel facilities, where the facility is NOT permitted for such operations, must obtain alternate permit coverage, currently under CDPS general permit COR900000. PART I Page 42 of 67 Permit No.: COG500000 2. Sector -Specific Benchmarks Table O-1 identifies benchmarks that apply to discharges associated with industrial activity from asphalt batch plants Table O-1. Sector Parameter Benchmark Monitoring Concentration Asphalt Paving Mixtures and Blocks (SIC 2951) Total Suspended Solids (TSS) 100 mg/L P. SECTOR -SPECIFIC REQUIREMENTS FOR CONCRETE BATCH PLANTS - Stormwater only The requirements of this Part apply to stormwater discharges associated with industrial activity from concrete batch plants (SIC Code 3273) located at sand and gravel facilities, and to areas of the permittee's facility where those sector -specific activities occur. These sector -specific requirements are in addition to any requirements specified elsewhere in this permit. 1. Concrete Batch Plants Concrete batch plants (permanent and mobile) that operate at sand and gravel facilities, where the facility is permitted for such operations, may be covered by this permit. Concrete batch plants that operate at sand and gravel facilities, where the facility is NOT permitted for such operations, must obtain alternate permit coverage, currently under CDPS general permit COR900000. 2. Additional Practice -Based Effluent Limits a. Good Housekeeping Measures. With good housekeeping, prevent or minimize the discharge of spilled cement, aggregate (including sand or gravel), settled dust, or other significant material in stormwater from paved portions of the site that are exposed to stormwater. Consider sweeping regularly or using other equivalent measures to minimize the presence of these materials. Indicate in the facility SWMP the frequency of sweeping or equivalent measures. Determine the frequency based on the amount of industrial activity occurring in the area and the frequency of precipitation, but it must be performed at least once a month if cement, aggregate, or settled dust are being handled or processed. The permittee must also prevent the exposure of fine granular solids (e.g., cement, etc.) to stormwater, where practicable, by storing these materials in enclosed silos, hoppers, or buildings, or under other covering. 3. Additional SWMP Requirements a. Drainage Area Site Map. Document in the SWMP the locations of the following, as applicable: dust control device; recycle/sedimentation pond, clarifier, or other device used for the treatment of process wastewater; and the areas that drain to the treatment device. b. Certification. For facilities producing ready -mix concrete, concrete block, brick, or similar products, include in the non- stormwater discharge certification a description of measures that ensure that process waste waters resulting from washing trucks, mixers, transport buckets, forms, or other equipment are discharged in accordance with CDPS requirements or are recycled. 4. Sector -Specific Benchmarks Table P-1 identifies benchmarks that apply to discharges associated with industrial activity from concrete batch plants Table P-1. Sector Parameter Benchmark Monitoring Concentration Ready -Mixed Concrete (SIC 3273) Total Suspended Solids (TSS) 100 mg/L Total Iron 1.0 mg/L PART I Page 43 of 67 Permit No.: COGS00000 Q. OTHER TERMS AND CONDITIONS - Stormwater only 1. All dischargers must comply with the lawful requirements of counties, drainage districts and other state or local agencies regarding any discharges of stormwater to storm drain systems or other water courses under their jurisdiction. 2. Reporting to Municipality — Any permitted facility discharging to a municipal storm sewer shall provide the municipality with a copy of the permit application, and/or Annual Reports, upon request. A copy of the SWMP shall also be provided to the municipality upon request. Part II Page 44 of 67 Permit No. COG500000 PART II A. NOTIFICATION REQUIREMENTS 1. Notification to Parties All notification requirements under this section shall be directed as follows: a. Oral Notifications, during normal business hours shall be to: Water Quality Protection Section — Industrial Compliance Program Water Quality Control Division Telephone: (303) 692-3500 b. Written notification shall be to: Water Quality Protection Section — Industrial Compliance Program Water Quality Control Division Colorado Department of Public Health and Environment WQCD-WQP-B2 4300 Cherry Creek Drive South Denver, CO 80246-1530 2. Change in Discharge The permittee shall give advance notice to the Division, in writing, of any planned physical alterations or additions to the permitted facility. Notice is required only when: a. The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged, or; b. The alteration or addition results in a significant change in the permittee's sludge use or disposal practices, and such alteration, addition, or change may justify the application of permit conditions that are different from or absent in the existing permit, including notification of additional use or disposal sites not reported pursuant to an approved land application plan. Whenever notification of any planned physical alterations or additions to the permitted facility is required pursuant to this section, the permittee shall furnish the Division such plans and specifications which the Division deems reasonably necessary to evaluate the effect on the discharge, the stream, or ground water. If the Division finds that such new or altered discharge might be inconsistent with the conditions of the permit, the Division shall require a new or revised permit application and shall follow the procedures specified in Sections 61.5 through 61.6, and 61.15 of the Colorado Discharge Permit System Regulations. 3. Noncompliance Notification The permittee shall give advance notice to the Division, in writing, of any planned changes in the permitted facility or activity that may result in noncompliance with permit requirements. a. If, for any reason, the permittee does not comply with or will be unable to comply with any discharge limitations or standards specified in this permit, the permittee shall, at a minimum, provide the Division with the following information: i) A description of the noncompliance and its cause; ii) The period of noncompliance, including exact dates and times and/or the anticipated time when the discharge will return to compliance; and iii) Steps being taken to reduce, eliminate, and prevent recurrence of the noncomplying discharge. b. The permittee shall report the following circumstances orally within twenty-four (24) hours from the time the permittee becomes aware of the circumstances, and shall mail to the Division a written report containing the Part II Page 45 of 67 Permit No. COG500000 information requested in Part II.A.4 (a) within five (5) working days after becoming aware of the following circumstances: i) Circumstances leading to any noncompliance which may endanger health or the environment regardless of the cause of the incident; ii) Circumstances leading to any unanticipated bypass which exceeds any effluent limitations in the permit; iii) Circumstances leading to any upset which causes an exceedance of any effluent limitation in the permit; iv) Daily maximum violations for any of the pollutants limited by Part I.A of this permit as specified in Part III of this permit. This includes any toxic pollutant or hazardous substance or any pollutant specifically identified as the method to control any toxic pollutant or hazardous substance. c. Unless otherwise indicated in this permit, the permittee shall report instances of non-compliance which are not required to be reported within 24 -hours at the time Discharge Monitoring Reports are submitted. The reports shall contain the information listed in sub -paragraph (a) of this section. 4. Transfer of Ownership or Control The permittee shall notify the Division, in writing, thirty (30) calendar days in advance of a proposed transfer of the permit. a. Except as provided in paragraph b. of this section, a permit may be transferred by a permittee only if the permit has been modified or revoked and reissued as provided in Section 61.8(8) of the Colorado Discharge Permit System Regulations, to identify the new permittee and to incorporate such other requirements as may be necessary under the Federal Act. b. A permit may be automatically transferred to a new permittee if: i) The current permittee notifies the Division in writing 30 calendar days in advance of the proposed transfer date; and ii) The notice includes a written agreement between the existing and new permittee(s) containing a specific date for transfer of permit responsibility, coverage and liability between them; and iii) The Division does not notify the existing permittee and the proposed new permittee of its intent to modify, or revoke and reissue the permit. iv) Fee requirements of the Colorado Discharge Permit System Regulations, Section 61.15, have been met. 5. Other Notification Requirements Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule in the permit, shall be submitted to the WQCD Industrial Compliance Program on the date listed in the compliance schedule section. The fourteen (14) calendar day provision in Regulation 61.8(4)(n)(i) has been incorporated into the due date. The permittee's notification of all anticipated noncompliance does not stay any permit condition. All existing manufacturing, commercial, mining, and silvicultural dischargers must notify the Division as soon as they know or have reason to believe: a. That any activity has occurred or will occur which would result in the discharge, on a routine or frequent basis, of any toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following "notification levels": i) One hundred micrograms per liter (100 µg/I); Part II Page 46 of 67 Permit No. COG500000 ii) Two hundred micrograms per liter (200 µg/I) for acrolein and acrylonitrile; five hundred micrograms per liter (500 µg/l) for 2.4-dinitrophenol and 2-methyl-4.6-dinitrophenol; and one milligram per liter (1.0 mg/I) for antimony; iii) Five (5) times the maximum concentration value reported for that pollutant in the permit application in accordance with Section 61.4(2)(g). iv) The level established by the Division in accordance with 40 C.F.R. § 122.44(f). b. That any activity has occurred or will occur which would result in any discharge, on a non -routine or infrequent basis, of a toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following "notification levels": i) Five hundred micrograms per liter (500 µg/l); ii) One milligram per liter (1 mg/I) for antimony; and iii) Ten (10) times the maximum concentration value reported for that pollutant in the permit application. iv) The level established by the Division in accordance with 40 C.F.R. § 122.44(f). 6. Bypass Notification If the permittee knows in advance of the need for a bypass, a notice shall be submitted, at least ten (10) calendar days before the date of the bypass, to the Division. The bypass shall be subject to Division approval and limitations imposed by the Division. Violations of requirements imposed by the Division will constitute a violation of this permit. 7. Bypass a. "Bypass" means the intentional diversion of waste streams from any portion of a treatment facility. b. Bypasses are prohibited and the Division may take enforcement action against the permittee for bypass, unless: i) The bypass is unavoidable to prevent loss of life, personal injury, or severe property damage; ii) There were no feasible alternatives to bypass such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime. This condition is not satisfied if adequate back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occurred during normal periods of equipment downtime or preventive maintenance; and iii) Proper notices were submitted in compliance with Part II.A.5. c. "Severe property damage" as used in this Subsection means substantial physical damage to the treatment facilities which causes them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production. d. The permittee may allow a bypass to occur which does not cause effluent limitations to be exceeded, but only if it also is for essential maintenance or to assure optimal operation. These bypasses are not subject to the provisions of paragraph (a) above. e. The Division may approve an anticipated bypass, after considering adverse effects, if the Division determines that the bypass will meet the conditions specified in paragraph (a) above. 8. Upsets a. "Upset" means an exceptional incident in which there is unintentional and temporary noncompliance with permit effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include Part II Page 47 of 67 Permit No. COG500000 noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventative maintenance, or careless or improper operation. b. Effect of an Upset An upset constitutes an affirmative defense to an action brought for noncompliance with permit effluent limitations if the requirements of paragraph (b) of this section are met. No determination made during administrative review of claims that noncompliance was caused by upset, and before an action for noncompliance, is final administrative action subject to judicial review. c. Conditions Necessary for a Demonstration of Upset A permittee who wishes to establish the affirmative defense of upset shall demonstrate through properly signed contemporaneous operating logs, or other relevant evidence that: i) An upset occurred and that the permittee can identify the specific cause(s) of the upset; and ii) The permitted facility was at the time being properly operated and maintained; and iii) The permittee submitted proper notice of the upset as required in Part II.A.4. of this permit (24 -hour notice); and iv) The permittee complied with any remedial measure necessary to minimize or prevent any discharge or sludge use or disposal in violation of this permit which has a reason able likelihood of adversely affecting human health or the environment. In addition to the demonstration required above, a permittee who wishes to establish the affirmative defense of upset for a violation of effluent limitations based upon water quality standards shall also demonstrate through monitoring, modeling or other methods that the relevant standards were achieved in the receiving water. d. Burden of Proof In any enforcement proceeding the permittee seeking to establish the occurrence of an upset has the burden of proof. 9. Submission of Incorrect or Incomplete Information Where the permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or in any report to the Division, the permittee shall promptly submit such facts or information. B. RESPONSIBILITIES 1. Reduction, Loss, or Failure of Treatment Facility The permittee has the duty to halt or reduce any activity if necessary to maintain compliance with the effluent limitations of the permit. Upon reduction, loss, or failure of the treatment facility, the permittee shall, to the extent necessary to maintain compliance with its permit, control production, control sources of wastewater, or all discharges, until the facility is restored or an alternative method of treatment is provided. This provision also applies to power failures, unless an alternative power source sufficient to operate the wastewater control facilities is provided. It shall not be a defense for a permittee in an enforcement action that it would be necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this permit. 2. Inspections and Right to Entry The permittee shall allow the Division and/or the authorized representative, upon the presentation of credentials: a. To enter upon the permittee's premises where a regulated facility or activity is located or in which any records are required to be kept under the terms and conditions of this permit; b. At reasonable times to have access to and copy any records required to be kept under the terms and conditions of this permit and to inspect any monitoring equipment or monitoring method required in the permit; and Part II Page 48 of 67 Permit No. COG500000 c. To enter upon the permittee's premises in a reasonable manner and at a reasonable time to inspect and/or investigate, any actual, suspected, or potential source of water pollution, or to ascertain compliance or non compliance with the Colorado Water Quality Control Act or any other applicable state or federal statute or regulation or any order promulgated by the Division. The investigation may include, but is not limited to, the following: sampling of any discharge and/or process waters, the taking of photographs, interviewing of any person having knowledge related to the discharge permit or alleged violation, access to any and all facilities or areas within the permittee's premises that may have any affect on the discharge, permit, or alleged violation. Such entry is also authorized for the purpose of inspecting and copying records required to be kept concerning any effluent source. d. The permittee shall provide access to the Division to sample the discharge at a point after the final treatment process but prior to the discharge mixing with state waters upon presentation of proper credentials. In the making of such inspections, investigations, and determinations, the Division, insofar as practicable, may designate as its authorized representatives any qualified personnel of the Department of Agriculture. The Division may also request assistance from any other state or local agency or institution. 3. Duty to Provide Information The permittee shall furnish to the Division, within a reasonable time, any information which the Division may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit, or to determine compliance with this permit. The permittee shall also furnish to the Division, upon request, copies of records required to be kept by this permit. 4. Availability of Reports Except for data determined to be confidential under Section 308 of the Federal Clean Water Act and the Colorado Discharge Permit System Regulations 5 CCR 1002-61, Section 61.5(4), all reports prepared in accordance with the terms of this permit shall be available for public inspection at the offices of the Division and the Environmental Protection Agency. The name and address of the permit applicant(s) and permittee(s), permit applications, permits and effluent data shall not be considered confidential. Knowingly making false statement on any such report may result in the imposition of criminal penalties as provided for in Section 309 of the Federal Clean Water Act, and Section 25-8-610 C.R.S. 5. Modification, Suspension, Revocation, or Termination of Permits By the Division The filing of a request by the permittee for a permit modification, revocation and reissuance, termination or a notification of planned changes or anticipated noncompliance, does not stay any permit condition. a. A permit may be modified, suspended, or terminated in whole or in part during its term for reasons determined by the Division including, but not limited to, the following: i) Violation of any terms or conditions of the permit; ii) Obtaining a permit by misrepresentation or failing to disclose any fact which is material to the granting or denial of a permit or to the establishment of terms or conditions of the permit; or iii) Materially false or inaccurate statements or information in the permit application or the permit. iv) A determination that the permitted activity endangers human health or the classified or existing uses of state waters and can only be regulated to acceptable levels by permit modifications or termination. b. A permit may be modified in whole or in part for the following causes, provided that such modification complies with the provisions of Section 61.10 of the Colorado Discharge Permit System Regulations: i) There are material and substantial alterations or additions to the permitted facility or activity which occurred after permit issuance which justify the application of permit conditions that are different or absent in the existing permit. Part II Page 49 of 67 Permit No. COG500000 ii) The Division has received new information which was not available at the time of permit issuance (other than revised regulations, guidance, or test methods) and which would have justified the application of different permit conditions at the time of issuance. For permits issued to new sources or new dischargers, this cause includes information derived from effluent testing required under Section 61.4(7)(e) of the Colorado Discharge Permit System Regulations. This provision allows a modification of the permit to include conditions that are less stringent than the existing permit only to the extent allowed under Section 61.10 of the Colorado Discharge Permit System Regulations. iii) The standards or regulations on which the permit was based have been changed by promulgation of amended standards or regulations or by judicial decision after the permit was issued. Permits may be modified during their terms for this cause only as follows: (A) The permit condition requested to be modified was based on a promulgated effluent limitation guideline, EPA approved water quality standard, or an effluent limitation set forth in 5 CCR 1002-62, § 62 et seq.; and (B) EPA has revised, withdrawn, or modified that portion of the regulation or effluent limitation guideline on which the permit condition was based, or has approved a Commission action with respect to the water quality standard or effluent limitation on which the permit condition was based; and (C) The permittee requests modification after the notice of final action by which the EPA effluent limitation guideline, water quality standard, or effluent limitation is revised, withdrawn, or modified; or (D) For judicial decisions, a court of competent jurisdiction has remanded and stayed EPA promulgated regulations or effluent limitation guidelines, if the remand and stay concern that portion of the regulations or guidelines on which the permit condition was based and a request is filed by the permittee in accordance with this Regulation, within ninety (90) calendar days of judicial remand. iv) The Division determines that good cause exists to modify a permit condition because of events over which the permittee has no control and for which there is no reasonable available remedy. v) Where the Division has completed, and EPA approved, a total maximum daily load (TMDL) which includes a wasteload allocation for the discharge(s) authorized under the permit. vi) The permittee has received a variance. vii) When required to incorporate applicable toxic effluent limitation or standards adopted pursuant to § 307(a) of the Federal act. viii) When required by the reopener conditions in the permit. ix) As necessary under 40 C.F.R. 403.8(e), to include a compliance schedule for the development of a pretreatment program. x) When the level of discharge of any pollutant which is not limited in the permit exceeds the level which can be achieved by the technology -based treatment requirements appropriate to the permittee under Section 61.8(2) of the Colorado Discharge Permit System Regulations. xi) To establish a pollutant notification level required in Section 61.8(5) of the Colorado Discharge Permit System Regulations. xii) To correct technical mistakes, such as errors in calculation, or mistaken interpretations of law made in determining permit conditions, to the extent allowed in Section 61.10 of the Colorado State Discharge Permit System Regulations. xiii) When required by a permit condition to incorporate a land application plan for beneficial reuse of sewage sludge, to revise an existing land application plan, or to add a land application plan. Part II Page 50 of 67 Permit No. COG500000 xiv) When another State whose waters may be affected by the discharge has not been notified. xv) For any other cause provided in Section 61.10 of the Colorado Discharge Permit System Regulations. c. At the request of a permittee, the Division may modify or terminate a permit and issue a new permit if the following conditions are met: i) The Regional Administrator has been notified of the proposed modification or termination and does not object in writing within thirty (30) calendar days of receipt of notification, ii) The Division finds that the permittee has shown reasonable grounds consistent with the Federal and State statutes and regulations for such modifications or termination; iii) Requirements of Section 61.15 of the Colorado Discharge Permit System Regulations have been met, and iv) Requirements of public notice have been met. d. For permit modification, termination, or revocation and reissuance, the Division may request additional information from the permittee. In the case of a modified permit, the Division may require the submission of an updated application. In the case of revoked and reissued permit, the Division shall require the submission of a new application. e. Permit modification (except for minor modifications), termination or revocation and reissuance actions shall be subject to the requirements of Sections 61.5(2), 61.5(3), 61.6, 61.7 and 61.15 of the Colorado Discharge Permit System Regulations. The Division shall act on a permit modification request, other than minor modification requests, within 180 calendar days of receipt thereof. Except for minor modifications, the terms of the existing permit govern and are enforceable until the newly issued permit is formally modified or revoked and reissued following public notice. f. Upon consent by the permittee, the Division may make minor permit modifications without following the requirements of Sections 61.5(2), 61.5(3), 61.7, and 61.15 of the Colorado Discharge Permit System Regulations. Minor modifications to permits are limited to: i) Correcting typographical errors; or ii) Increasing the frequency of monitoring or reporting by the permittee; or iii) Changing an interim date in a schedule of compliance, provided the new date of compliance is not more than 120 calendar days after the date specific in the existing permit and does not interfere with attainment of the final compliance date requirement; or iv) Allowing for a transfer in ownership or operational control of a facility where the Division determines that no other change in the permit is necessary, provided that a written agreement containing a specific date for transfer of permit responsibility, coverage and liability between the current and new permittees has been submitted to the Division; or v) Changing the construction schedule for a discharger which is a new source, but no such change shall affect a discharger's obligation to have all pollution control equipment installed and in operation prior to discharge; or vi) Deleting a point source outfall when the discharge from that outfall is terminated and does not result in discharge of pollutants from other outfalls except in accordance with permit limits. vii) Incorporating conditions of a POTW pretreatment program that has been approved in accordance with the procedures in 40 CFR 403.11 (or a modification thereto that has been approved in accordance with the procedures in 40 CFR 403.18) as enforceable conditions of the POTW's permits. g. When a permit is modified, only the conditions subject to modification are reopened. If a permit is revoked and reissued, the entire permit is reopened and subject to revision and the permit is reissued for a new term. Part II Page 51 of 67 Permit No. COG500000 h. The filing of a request by the permittee for a permit modification, revocation and reissuance or termination does not stay any permit condition. i. All permit modifications and reissuances are subject to the antibacksliding provisions set forth in 61.10(e) through (g). j. If cause does not exist under this section, the Division shall not modify or revoke and reissue the permit. 6. Oil and Hazardous Substance Liability Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties to which the permittee is or may be subject to under Section 311 (Oil and Hazardous Substance Liability) of the Clean Water Act. 7. State Laws Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties established pursuant to any applicable State law or regulation under authority granted by Section 510 of the Clean Water Act. Nothing in this permit shall be construed to prevent or limit application of any emergency power of the division. 8. Permit Violations Failure to comply with any terms and/or conditions of this permit shall be a violation of this permit. The discharge of any pollutant identified in this permit more frequently than or at a level in excess of that authorized shall constitute a violation of the permit. Except as provided elsewhere in this permit, nothing in this permit shall be construed to relieve the permittee from civil or criminal penalties for noncompliance (40 CFR 122.41(a)(1)). 9. Severability The provisions of this permit are severable. If any provisions or the application of any provision of this permit to any circumstances, is held invalid, the application of such provision to other circumstances and the application of the remainder of this permit shall not be affected. 10. Confidentiality Any information relating to any secret process, method of manufacture or production, or sales or marketing data which has been declared confidential by the permittee, and which may be acquired, ascertained, or discovered, whether in any sampling investigation, emergency investigation, or otherwise, shall not be publicly disclosed by any member, officer, or employee of the Commission or the Division, but shall be kept confidential. Any person seeking to invoke the protection of this Subsection (12) shall bear the burden of proving its applicability. This section shall never be interpreted as preventing full disclosure of effluent data. 11. Fees The permittee is required to submit payment of an annual fee as set forth in the 2005 amendments to the Water Quality Control Act. Section 25-8-502 (I) (b), and the Colorado Discharge Permit System Regulations 5 CCR 1002-61, Section 61.15 as amended. Failure to submit the required fee when due and payable is a violation of the permit and will result in enforcement action pursuant to Section 25-8-601 et. seq., C.R.S. 1973 as amended. 12. Duration of Permit The duration of a permit shall be for a fixed term and shall not exceed five (5) years. If the permittee desires to continue to discharge, a permit renewal application shall be submitted at least one hundred eighty (180) calendar days before this permit expires. Filing of a timely and complete application shall cause the expired permit to continue in force to the effective date of the new permit. The permit's duration may be extended only through administrative extensions and not through interim modifications. If the permittee anticipates there will be no discharge after the expiration date of this permit, the Division should be promptly notified so that it can terminate the permit in accordance with Part II.B.4. 13. Section 307 Toxics If a toxic effluent standard or prohibition, including any applicable schedule of compliance specified, is established by regulation pursuant to Section 307 of the Federal Act for a toxic pollutant which is present in the permittee's discharge and such standard Part II Page 52 of 67 Permit No. COG500000 or prohibition is more stringent than any limitation upon such pollutant in the discharge permit, the Division shall institute proceedings to modify or revoke and reissue the permit to conform to the toxic effluent standard or prohibition. 14. Effect of Permit Issuance a. The issuance of a permit does not convey any property or water rights in either real or personal property, or stream flows or any exclusive privilege. b. The issuance of a permit does not authorize any injury to person or property or any invasion of personal rights, nor does it authorize the infringement of federal, state, or local laws or regulations. c. Except for any toxic effluent standard or prohibition imposed under Section 307 of the Federal act or any standard for sewage sludge use or disposal under Section 405(d) of the Federal act, compliance with a permit during its term constitutes compliance, for purposes of enforcement, with Sections 301, 302, 306, 318, 403, and 405(a) and (b) of the Federal act. However, a permit may be modified, revoked and reissued, or terminated during its term for cause as set forth in Section 61.8(8) of the Colorado Discharge Permit System Regulations. d. Compliance with a permit condition which implements a particular standard for biosolid use or disposal shall be an affirmative defense in any enforcement action brought for a violation of that standard for biosolid use or disposal. PART III Page 53 of 67 Permit No.: COG500000 PART III CATEGORICAL INDUSTRIES Aluminum Forming Asbestos Manufacturing Battery Manufacturing Builders' Paper and Board Mills Canned & Preserved Fruits and Vegetables Processing Canned & Preserved Seafood Processing Carbon Black Manufacturing Cement Manufacturing Coal Mining Coil Coating Copper Forming Dairy Products Processing Electrical and Electronic Components Electroplating Explosives Manufacturing Feedlots Ferroalloy Manufacturing Fertilizer Manufacturing Glass Manufacturing Grain Mills Gum and Wood Chemicals Manufacturing Hospital Ink Formulation Inorganic Chemicals Manufacturing Iron and Steel Manufacturing Leather Tanning and Finishing Volatiles acrolein acrylonitrile benzene bromoform carbon tetrachloride chlorobenzene chlorodibromomethane chloroethane 2-chloroethylvinyl ether chloroform dichlorobromomethane 1,1-dichlorethane 1,2-dichlorethane 1,1-dichlorethylene 1,2-dichlorpropane 1,3-dichlorpropylene ethylbenzene methyl bromide methyl chloride methylene chloride Meat Products Metal Finishing Metal Molding and Casting (Foundries) Mineral Mining and Processing Nonferrous Metals Manufacturing Nonferrous Metals Forming and Metal Powders Oil and Gas Extraction O rganic Chemicals, Plastics, and Synthetic Fibers O re Mining and Dressing Paint Formulation Paving and Roofing Materials (Tars and Asphalt) Pesticide Chemicals Petroleum Refining Pharmaceutical Manufacturing Phosphate Manufacturing Photographic Plastics Molding and Forming Porcelain Enameling Pulp, Paper, and Paperboard Manufacturing Rubber Manufacturing Soap and Detergent Manufacturing Steam Electric Power Generating Sugar Processing Textile Mills Timber Products Processing PRIORITY POLLUTANTS AND HAZARDOUS SUBSTANCES ORGANIC TOXIC POLLUTANTS IN EACH OF FOUR FRACTIONS IN ANALYSIS BY GAS CHROMATOGRAPHY/MASS SPECTROSCOPY (GC/MS) Base/Neutral acenaphthene acenaphthylene anthracene benzidine benzo(a)anthracene benzo(a)pyrene 3,4-benzofluoranthene benzo(ghi)perylene benzo(k)fluoranthene bis(2-chloroethoxy)methane bis(2-chloroethyl)ether bis(2-chloroisopropyl)ether bis(2-ethylhexyl)phthalate 4-bromophenyl phenyl ether butylbenzyl phthalate 2-chloronaphthalene 4-chlorophenyl phenyl ether chrysene dibenzo(a,h)anthracene 1,2-dichlorobenzene Acid Compounds 2-chlorophenol 2,4-dichlorophenol 2,4,-dimethylphenol 4,6-dinitro-o-cresol 2,4-dinitrophenol 2-nitrophenol 4-nitrophenol p-chloro-m-cresol pentachlorophenol Phenol 2,4,6-trichlorophenol Pesticides aldrin alpha-BHC beta-BHC gamma-BHC delta-BHC chlordane 4,4° -DDT 4,4'-DDE 4,4'-DDD dieldrin alpha-endosulfan beta-endosulfan e ndosulfan sulfate e ndrin e ndrin aldehyde heptachlor heptachlor epoxide PCB -1242 PCB -1254 PCB -1221 PART III Page 54 of 67 Permit No.: COG500000 PRIORITY POLLUTANTS AND HAZARDOUS SUBSTANCES ORGANIC TOXIC POLLUTANTS IN EACH OF FOUR FRACTIONS IN ANALYSIS BY GAS CHROMATOGRAPHY/MASS SPECTROSCOPY (GC/MS) Volatiles 1,1,2,2-tetrachloroethane tetrachloroethylene Toluene 1,2-trans-dichloroethylene 1,1,1-trichloroethane 1,1,2-trichloroethane trichloroethylene vinyl chloride Base/Neutral Acid Compounds 1,3-dichlorobenzene 1,4-dichlorobenzene 3,3-dichlorobenzidine i ne diethyl phthalate dimethyl phthalate di -n -butyl phthalate 2,4-dinitrotoluene 2,6-dinitrotoluene di-n-octyl phthalate 1,2-diphenylhydrazine (as azobenzene) fluorene fluoranthene hexachlorobenzene hexachlorobutadiene hexachlorcyclopentad iene hexachloroethane indeno(1,2,3-cd)pyrene isophorone n aphthalene n itrobenzene N -nitrosodimethylamine N -nitrosodi-n-propylamine N -nitrosodiphenylamine phenanthrene pyrene 1,2,4-trichlorobenzene lorobenzene OTHER TOXIC POLLUTANTS (AMMONIA, METALS AND CYANIDE) AND TOTAL PHENOLS Antimony, Total Arsenic, Total Beryllium, Total Cadmium, Total Chromium, Total Copper, Total Lead, Total Mercury, Total Nickel, Total Selenium, Total Silver, Total Thallium, Total Zinc, Total Cyanide, Total Phenols, Total Pesticides PCB -1232 PCB -1248 PCB -1260 PCB -1016 toxaphene PART III Page 55 of 67 Permit No.: COG500000 TOXIC POLLUTANTS AND HAZARDOUS SUBSTANCES REQUIRED TO BE IDENTIFIED BY EXISTING DISCHARGERS IF EXPECTED TO BE PRESENT Toxic Pollutants Asbestos Hazardous Substances Acetaldehyde Allyl alcohol Allyl chloride Amyl acetate Aniline Benzonitrile Benzyl chloride Butyl acetate Butylamine Captan Carbaryl Carbofuran Carbon disulfide Chlorpyrifos Coumaphos Cresol Crotonaldehyde Cyclohexane 2,4-D(2,4-Dichlorophenoxy acetic acid) Diazinon Dicamba Dichlobenil Dichlone 2,2-Dichloropropionic acid Dichlorvos Diethyl amine Dimethyl amine Dinitrobenzene Diquat Disulfoton Diuron Epichlorohydrin Ethanolamine Ethion Ethylene diamine Ethylene dibromide Formaldehyde Furfural Guthion Isoprene Isopropanolamine Keithane Kepone Malathion Mercaptodimethur Methoxychlor Methyl mercaptan Methyl methacrylate Methyl parathion Mexacarbate Monoethyl amine Monomethyl amine Naled Napthenic acid Nitrotoluene Parathion Phenolsulfanate Phosgene Propargite Propylene oxide Pyrethrins Quinoline Resorcinol Strontium Strychnine Styrene TDE (Tetrachlorodiphenylethane) 2,4,5-T (2,4,5-Trichlorophenoxy acetic acid) 2,4,5-TP [2-(2,4,5-Trichlorophenoxy) propanoic acid] Trichlorofan Triethylamine Trimethylamine Uranium Vandium Vinyl Acetate Xylene Xylenol Zirconium Appendix A Page 56 of 67 Permit No.: COG500000 Appendix A — Description of Standard Industrial Classification (SIC) Code Major Group 14 facilities Major group 14 includes establishments primarily engaged in mining or quarrying, developing mines, or exploring for nonmetallic minerals, except fuels. Dimension Stone (SIC code 1411) - Establishments primarily engaged in mining or quarrying dimension stone. Also included are establishments engaged in producing rough blocks and slabs. Crushed and Broken Limestone (SIC code 1422) - Establishments primarily engaged in mining or quarrying crushed and broken limestone, including related rocks, such as dolomite, cement rock, marl, travertine, and calcareous tufa. Crushed and Broken Granite (SIC code 1423) - Establishments primarily engaged in mining or quarrying crushed and broken granite, including related rocks, such as gneiss, syenite, and diorite. Crushed and Broken Stone, Not Elsewhere Classified (SIC code 1429) - Establishments primarily engaged in mining or quarrying crushed and broken stone, not elsewhere classified. Construction Sand and Gravel (SIC code 1442) - Establishments primarily engaged in operating sand and gravel pits and dredges, and in washing, screening, or otherwise preparing sand and gravel for construction uses. Industrial Sand (SIC code 1446) - Establishments primarily engaged in operating sand pits and dredges, and in washing, screening, and otherwise preparing sand for uses other than construction, such as glassmaking, molding, and abrasives. Kaolin and Ball Clay (SIC code 1455) - Establishments primarily engaged in mining, milling, or otherwise preparing kaolin or ball clay, including china clay, paper clay, and slip clay. Clay, Ceramic, and Refractory Minerals, Not Elsewhere Classified (SIC code 1459) - Establishments primarily engaged in mining, milling, or otherwise preparing clay, ceramic, or refractory minerals, not elsewhere classified. Potash, Soda, and Borate Minerals (SIC code 1474) - Establishments primarily engaged in mining, milling, or otherwise preparing natural potassium, sodium, or boron compounds. Phosphate Rock (SIC code 1475) - Establishments primarily engaged in mining, milling, drying, calcining, sintering, or otherwise preparing phosphate rock, including apatite. Chemical and Fertilizer Mineral Mining, Not Elsewhere Classified (SIC code 1479) - Establishments primarily engaged in mining, milling, or otherwise preparing chemical or fertilizer mineral raw materials, not elsewhere classified. Nonmetallic Minerals Services, Except Fuels (SIC code 1481) - Establishments primarily engaged in the removal of overburden, strip mining, and other services for nonmetallic minerals, except fuels, for others on a contract or fee basis. Miscellaneous Nonmetallic Minerals, Except Fuels (SIC code 1481) - Establishments primarily engaged in mining, quarrying, milling, or otherwise preparing nonmetallic minerals, except fuels. This industry includes the shaping of natural abrasive stones at the quarry. Appendix B Page 57 of 67 Permit No.: COG500000 Appendix B — Failures/Violations of the WET Permit Limit and Automatic Compliance Response A. Failures and Violations of the Permit Limit 1. Acute Testing: An acute WET test failure/violation is whenever the LCSO, which represents an estimate of the effluent concentration which is lethal to 50% of the test organisms in the time period prescribed by the test, is found to be less than or equal to 100% effluent. When WET testing is specified in the certification, an acute WET test failure is a violation of the permit. In the event of any acute WET test failure/violation, the permittee must provide written notification of the failure to the Division, along with a statement as to whether accelerated testing or a Toxicity Identification Evaluation (TIE) is being performed, unless otherwise exempted, in writing, by the Division. Notification must be received by the Division within 14 calendar days of the permittee receiving notice of the WET testing results. 2. Chronic testing: A chronic WET test is considered to have failed one of the two statistical endpoints when either the NOEC or the IC25 are at any effluent concentration less than the IWC. The IWC for this permit has been determined to be 100% effluent, as dilution considerations do not apply to this general permit. A chronic WET test violation is when both the NOEC and the IC25 are at any effluent concentration less than the IWC. When specified in the certification, a chronic WET test failure is a violation of the permit. The permittee must provide written notification to the Division if a chronic WET test violation occurs, or if two consecutive reporting periods have resulted in failure of one of the two statistical endpoints (regardless of which statistical endpoints are failed). Such notification should explain whether it was a violation, a failure of both endpoints when only monitoring is required, or two consecutive failures of a single endpoint. The written notification must also indicate whether accelerated testing or a Toxicity Identification Evaluation or Toxicity Reduction Evaluation (TIE or TRE) is being performed, unless otherwise exempted, in writing, by the Division. Notification must be received by the Division within 14 calendar days of the permittee receiving notice of the WET testing results. B. Automatic Compliance Response 1. The permittee is responsible for implementing the automatic compliance response provisions of this permit when one of the following occurs: a. For all WET testing: i. there is a violation of the permit limit (as described for acute and chronic limitations above); ii. the permittee is otherwise informed by the Division that a compliance response is necessary. b. For acute WET testing: i. during a report -only period, when the LC50 endpoint is less than the applicable IWC c. For chronic WET testing: i. two consecutive monitoring periods have resulted in failure of one of the two statistical endpoints (either the IC25 or the NOEC). Note that this provision is applicable during 'report' only periods as well as when permit limitations are applicable. ii. during a report only period, when both the NOEC and the IC25 are at any effluent concentration less than the IWC. 2. When one of the above listed events occurs, the following automatic compliance response shall apply. The permittee shall either: a. conduct accelerated testing using the single species found to be more sensitive as described in this appendix, Part C, or b. conduct a Toxicity Identification Evaluation / Toxicity Reduction Evaluation (TIE/TRE) investigation as described below in this appendix, Part D. Appendix B Page 58 of 67 Permit No.: COG500000 C. Accelerated Testing If accelerated testing is being performed, testing will be at least once every two weeks for up to five tests, at the appropriate IWC, but only one test should be run at a time. For chronic WET testing, only the IC25 statistical endpoint is used to determine if the test passed or failed at the appropriate IWC. However, if accelerated testing is required due to failure of one statistical endpoint in two consecutive monitoring periods, and in both of those failures it was the NOEC endpoint that was failed, then the NOEC shall be the only statistical endpoint used to determined whether the accelerated testing passed or failed at the appropriate IWC. Accelerated testing shall continue until; 1) two consecutive tests fail or three of five tests fail, in which case a pattern of toxicity has been demonstrated or 2) two consecutive tests pass or three of five tests pass, in which case no pattern of toxicity has been found. Note that the same dilution series should be used in the accelerated testing as was used in the initial test(s) that result in the accelerated testing requirement. If no pattern of toxicity is found the toxicity episode is considered to be ended and routine testing is to resume. If a pattern of toxicity is found, a TIE/TRE investigation is to be performed. If a pattern of toxicity is not demonstrated but a significant level of erratic toxicity is found, the Division may require an increased frequency of routine monitoring or some other modified approach. The permittee shall provide written notification of the results within 14 calendar days of completion of the Pattern of Toxicity/No Toxicity demonstration. D. Toxicity Identification Evaluation / Toxicity Reduction Evaluation (TIE/TRE) If a TIE/TRE is being performed, the results of the investigation are to be received by the Division within 180 calendar days of the demonstration of acute WET in the routine test, as defined above, or if accelerated testing was performed, the date the pattern of toxicity is demonstrated. A status report is to be provided to the Division at the 60 and 120 calendar day points of the TIE/TRE investigation. The Division may extend the time frame for investigation where reasonable justification exists. A request for an extension must be made in writing and received prior to the 180 calendar day deadline. Such request must include a justification and supporting data for such an extension. Under a TIE, the permittee may use the time for investigation to conduct a preliminary TIE (PTIE) or move directly into the TIE. A PTIE consists of a brief search for possible sources of WET, where a specific parameter(s) is reasonably suspected to have caused such toxicity, and could be identified more simply and cost effectively than a formal TIE. If the PTIE allows resolution of the WET incident, the TIE need not necessarily be conducted in its entirety. If, however, WET is not identified or resolved during the PTIE, the TIE must be conducted within the allowed 180 calendar day time frame. The Division recommends that the EPA guidance documents regarding TIEs be followed. If another method is to be used, this procedure should be submitted to the Division prior to initiating the TIE. If the pollutant(s) causing toxicity is/are identified, and is/are controlled by a permit effluent limitation(s), this permit may be modified upon request to adjust permit requirements regarding the automatic compliance response. If the pollutant(s) causing toxicity is/are identified, and is/are not controlled by a permit effluent limitation(s), the Division may develop limitations the parameter(s), and the permit may be reopened to include these limitations. If the pollutant causing toxicity is not able to be identified, or is unable to be specifically identified, or is not able to be controlled by an effluent limit, the permittee will be required to either: 1. Conduct an investigation which demonstrates actual instream aquatic life conditions upstream and downstream of the discharge, or identify, for Division approval, and conduct an alternative investigation which demonstrates the actual instream impact. This should include WET testing and chemical analyses of the ambient water. Depending on the results of the study, the permittee may also be required to identify the control program necessary to eliminate the toxicity and its cost. Data collected may be presented to the WQCC for consideration at the next appropriate triennial review of the stream standards; or 2. Move to a TRE by identifying the necessary control program or activity and proceed with elimination of the toxicity so as to meet the WET effluent limit. Appendix B Page 59 of 67 Permit No.: COG500000 If toxicity spontaneously disappears in the midst of a TIE, the permittee shall notify the Division within 10 calendar days of such disappearance. The Division may require the permittee to conduct accelerated testing to demonstrate that no pattern of toxicity exists, or may amend the permit to require an increased frequency of WET testing for some period of time. If no pattern of toxicity is demonstrated through the accelerated testing or the increased monitoring frequency, the toxicity incident response will be closed and normal WET testing shall resume. The control program developed during a TRE consists of the measures determined to be the most feasible to eliminate WET. This may happen through the identification of the toxicant(s) and then a control program aimed specifically at that toxicant(s) or through the identification of more general toxicant treatability processes. A control program is to be developed and submitted to the Division within 180 calendar days of beginning a TRE. Status reports on the TRE are to be provided to the Division at the 60 and 120 calendar day points of the TRE investigation. If toxicity spontaneously disappears in the midst of a TRE, the permittee shall notify the Division within 10 calendar days of such disappearance. The Division may require the permittee to conduct accelerated testing to demonstrate that no pattern of toxicity exists, or may amend the permit to require an increased frequency for some period of time. If no pattern of toxicity is demonstrated through the accelerated testing or the increased monitoring frequency, the toxicity incident response will be closed and normal WET testing shall resume. Appendix C Page 60 of 67 Permit No.: COG500000 Appendix C — Definitions 1. "Acute Toxicity" — The acute toxicity limitation is exceeded if the LC50 is at any effluent concentration less than or equal to the IWC indicated in this permit. 2. "Applicable water quality criterion (AWQC)" is the quantitation target level or goal. The AWQC may be one of the following: Where an effluent limit has been established, i. The AWQC is the effluent limit. Where an effluent limit has not been established, the AWQC may be i. An applicable technology based effluent limit (TBEL); ii. Half of a water quality standard; iii. Half of a water quality standard as assessed in the receiving water, or potential WQBEL; or iv. Half of a potential antidegradation based effluent limitation, which can be an antidegradation based average concentration or a potential non -impact limit. 3. "Asphalt batch plant" — refers to the manufacturing plant that combines aggregate and an asphalt binder to produce asphalt concrete. 4. "Asphalt concrete" — produced in a manufacturing plant (asphalt batch plant) and is known by many different names, such as hot mix asphalt, plant mix, bituminous mix, bituminous concrete, etc. 5. "Best Management Practices (BMPs)" — schedules of activities, practices (and prohibitions of practices), structures, vegetation, maintenance procedures, and other management practices to prevent or reduce the discharge of pollutants to state waters. BMPs also include treatment requirements, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. See 5 CCR 1002-61.2(9). 6. "Chronic toxicity", which includes lethality and growth or reproduction, occurs when the NOEC and IC25 are at an effluent concentration less than the IWC indicated in this permit. 7. "Composite" sample is a minimum of four (4) grab samples collected at equally spaced two (2) hour intervals and proportioned according to flow. For a SBR type treatment system, a composite sample is defined as sampling equal aliquots during the beginning, middle and end of a decant period, for two consecutive periods during a day (if possible). 8. "Continuous" measurement, is a measurement obtained from an automatic recording device which continually measures the effluent for the parameter in question, or that provides measurements at specified intervals. 9. "Control Measure" refers to any BMP or other method (including effluent limitations) used to prevent or reduce the discharge of pollutants to waters of the state. 10. "Daily Maximum limitation" for all parameters (except temperature, pH and dissolved oxygen) means the limitation for this parameter shall be applied as an average of all samples collected in one calendar day. For these parameters the DMR shall include the highest of the daily averages. For pH and dissolved oxygen, this means an instantaneous maximum (and/or instantaneous minimum) value. The instantaneous value is defined as the analytical result of any individual sample. For pH and dissolved oxygen, DMRs shall include the maximum (and/or minimum) of all instantaneous values within the calendar month. Any value beyond the noted daily maximum limitation for the indicated parameter shall be considered a violation of this permit. For temperature, see Daily Maximum Temperature. 11. "Daily Maximum Temperature (DM)" is defined in the Basic Standards and Methodologies for Surface Water 1002-31, as the highest two-hour average water temperature recorded during a given 24 -hour period. This will be determined using a rolling 2 - hour maximum temperature. If data is collected every 15 minutes, a 2 hour maximum can be determined on every data point after the initial 2 hours of collection. Note that the time periods that overlap days (Wednesday night to Thursday morning) do not matter as the reported value on the DMR is the greatest of all the 2 -hour averages. For example data points collected at: Appendix C Page 61 of 67 Permit No.: COG500000 08:15, 08:30, 08:45, 09:00, 09:15, 09:30, 09:45, 10:00, would be averaged for a single 2 hour average data point 08:30, 08:45, 09:00, 09:15, 09:30, 09:45, 10:00, 10:15, would be averaged for a single 2 hour average data point 08:45, 09:00, 09:15, 09:30, 09:45, 10:00, 10:15, 10:30, would be averaged for a single 2 hour average data point This would continue throughout the course of a calendar day. The highest of these 2 hour averages over a month would be reported on the DMR as the daily maximum temperature. At the end/beginning of a month, the collected data should be used for the month that contains the greatest number of minutes in the 2 -hour maximum. Data from 11 pm to 12:59 am, would fall in the previous month. Data collected from 11:01 pm to 1:00 am would fall in the new month. 12. "Discharge" - when used without qualification, means the "discharge of a pollutant." See 5 CCR 1002-61.2(22). 13. "Discharge of a pollutant" - the introduction or addition of a pollutant into state waters. See 25-8-103(3) C.R.S. 14. "Dissolved (D) metals fraction" is defined in the Basic Standards and Methodologies for Surface Water 1002-31, as that portion of a water and suspended sediment sample which passed through a 0.40 or 0.45 UM (micron) membrane filter. Determinations of "dissolved" constituents are made using the filtrate. This may include some very small (colloidal) suspended particles which passed through the membrane filter as well as the amount of substance present in true chemical solution. 15. "Geometric mean" for E. coli bacteria concentrations, the thirty (30) day and seven (7) day averages shall be determined as the geometric mean of all samples collected in a thirty (30) day period and the geometric mean of all samples taken in a seven (7) consecutive day period respectively. The geometric mean may be calculated using two different methods. For the methods shown, a, b, c, d, etc. are individual sample results, and n is the total number of samples. Method 1: (1/n) Geometric Mean = (a*b*c*d*...) Method 2: "*" - means multiply Geometric Mean = antilog ( [log(a)+log(b)+log(c)+log(d)+...]/n ) Graphical methods, even though they may also employ the use of logarithms, may introduce significant error and may not be used. In calculating the geometric mean, for those individual sample results that are reported by the analytical laboratory to be "less than" a numeric value, a value of 1 should be used in the calculations. If all individual analytical results for the month are reported to be less than numeric values, then report "less than" the largest of those numeric values on the monthly DMR. Otherwise, report the calculated value. For any individual analytical result of "too numerous to count" (TNTC), that analysis shall be considered to be invalid and another sample shall be promptly collected for analysis. If another sample cannot be collected within the same sampling period for which the invalid sample was collected (during the same month if monthly sampling is required, during the same week if weekly sampling is required, etc.), then the following procedures apply: i. A minimum of two samples shall be collected for coliform analysis within the next sampling period. ii. If the sampling frequency is monthly or less frequent: For the period with the invalid sample results, leave the spaces on the corresponding DMR for reporting coliform results empty and attach to the DMR a letter noting that a result of TNTC was obtained for that period, and explain why another sample for that period had not been collected. If the sampling frequency is more frequent than monthly: Eliminate the result of TNTC from any further calculations, and use all the other results obtained within that month for reporting purposes. Attach a letter noting that a result of TNTC was obtained, and list all individual analytical results and corresponding sampling dates for that month. Appendix C Page 62 of 67 Permit No.: COG500000 16. "Good Engineering, Hydrologic and Pollution Control Practices" - methods, procedures, and practices that a) are based on basic scientific fact(s); b) reflect best industry practices and standards; c) are appropriate for the conditions and pollutant sources; and d) provide appropriate solutions to meet the associated permit requirements, including all effluent limitations. 17. "Grab" sample, is a single "dip and take" sample so as to be representative of the parameter being monitored. 18. "IC25" or "Inhibition Concentration" is a point estimate of the toxicant concentration that would cause a given percent reduction in a non -lethal biological measurement (e.g. growth or reproduction) calculated from a continuous model (i.e. interpolation method). IC25 is a point estimate of the toxic concentration that would cause a 25 -percent reduction in a non- lethal biological measurement. 19. "Impaired Water" (or "Water Quality Impaired Water")— A water is impaired for purposes of this permit if it has been identified by a State or EPA pursuant to Section 303(d) of the Clean Water Act as not meeting applicable State water quality standards (these waters are called "water quality limited segments" under 40 CFR 30.2(j)). Impaired waters include both waters with approved or established TMDLs, and those for which a TMDL has not yet been approved or established. 20. "Inactive mining operations" — Regulation 61.3(2)(e)(iii)(C) identifies that "inactive mining operations" are mining sites that are not being actively mined, but which have an identifiable owner/operator; inactive mining sites do not include sites where mining claims are being maintained prior to disturbances associated with the extraction, beneficiation, or processing of mined materials, nor sites where minimal activities are undertaken for the sole purpose of maintaining a mining claim). This term includes the following types of facilities that have an identifiable owner/operator: • mineral mining and/or milling occurred in the past but is not covered by an active mining permit issued by DRMS; • operations are limited seasonally (i.e., intermittent operations), consistent with DRMS requirements for notification, only during the portion of the year when the facility is not active; or • operations cease for 180 -days or more for reasons not associated with intermittent status, and still has reserves (consistent with temporary cessation status as defined by DRMS), only during the time period the facility is not active; or • exploration or extraction activities have ceased permanently. 21. "Industrial Activity" — for this permit means those activities identified by the SIC codes described in the applicability section of the permit. 22. "Industrial Stormwater" - stormwater runoff from industrial activity. 23. "In -situ" measurement is defined as a single reading, observation or measurement taken in the field at the point of discharge. 24. "Instantaneous" measurement is a single reading, observation, or measurement performed on site using existing monitoring facilities. 25. "LC50" or "Lethal Concentration" is the toxic or effluent concentration that would cause death in 50 percent of the test organisms over a specified period of time. 26. "Maximum Weekly Average Temperature (MWAT)" is defined in the Basic Standards and Methodologies for Surface Water 1002-31, as an implementation statistic that is calculated from field monitoring data. The MWAT is calculated as the largest mathematical mean of multiple, equally spaced, daily temperatures over a seven-day consecutive period, with a minimum of three data points spaced equally through the day. For lakes and reservoirs, the MWAT is assumed to be equivalent to the maximum WAT from at least three profiles distributed throughout the growing season (generally July -September). The MWAT is calculated by averaging all temperature data points collected during a calendar day, and then averaging the daily average temperatures for 7 consecutive days. This 7 day averaging period is a rolling average, i.e. on the 8th day, the MWAT will be the averages of the daily averages of days 2-8. The value to be reported on the DMR is the highest of all the rolling 7 -day averages throughout the month. For those days that are at the end/beginning of the month, the data shall be reported for the month that contains 4 of the 7 days. Appendix C Page 63 of 67 Permit No.: COG500000 Day 1: Average of all temperature data collected during the calendar day. Day 2: Average of all temperature data collected during the calendar day. Day 3: Average of all temperature data collected during the calendar day. Day 4: Average of all temperature data collected during the calendar day. Day 5: Average of all temperature data collected during the calendar day. Day 6: Average of all temperature data collected during the calendar day. Day 7: Average of all temperature data collected during the calendar day. 1st MWAT Calculation as average of previous 7 days Day 8: Average of all temperature data collected during the calendar day. 2nd MWAT Calculation as average of previous 7 days Day 9: Average of all temperature data collected during the calendar day. 3rd MWAT Calculation as average of previous 7 days 27. "Measurable storm event" - a storm event that results in an actual discharge from the facility. 28. "Minimize" - reduce and/or eliminate to the extent achievable using control measures (including best management practices) that are technologically available and economically practicable and achievable in light of best industry practice. 29. "Minimum level (ML)" means the lowest concentration of an analyte that can be accurately and precisely quantified using a given method, as determined by the laboratory. 30. "New Discharger" - means any building, structure, facility, or installation from which there is or may be a discharge of pollutants that did not commence at the particular site before August 13, 1979, that is not a new source, and that has never received a final effective permit for discharges at the site. See 5 CCR 1002-61.2(65). 31. "NOEC" or "No -Observed -Effect -Concentration" is the highest concentration of toxicant to which organisms are exposed in a full life cycle or partial life cycle (short term) test, that causes no observable adverse effects on the test organisms (i.e. the highest concentration of toxicant in which the values for the observed responses are not statistically different from the controls). This value is used, along with other factors, to determine toxicity limits in permits. 32. "No exposure" — all industrial materials or activities are protected by a storm -resistant shelter to prevent exposure to rain, snow, snowmelt, and/or runoff. 5 CCR 1002-61.3(2)(h). 33. "Person" - an individual, corporation, partnership, association, state or political subdivision thereof, federal agency, state agency, municipality, Commission, or interstate body. See 5 CCR 1002-61.2(73). 34. "Point source" - any discernible, confined, and discrete conveyance, including, but not limited to, any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. "Point Source" does not include irrigation return flow. See 5 CCR 1002- 61.2(75). 35. "Pollutant" - dredged spoil, dirt, slurry, solid waste, incinerator residue, sewage, sewage sludge, garbage, trash, chemical waste, biological nutrient, biological material, radioactive material, heat, wrecked or discarded equipment, rock, sand, or any industrial, municipal or agricultural waste. See 5 CCR 1002-61.2(76). 36. "Potentially dissolved (PD) metals fraction" is defined in the Basic Standards and Methodologies for Surface Water 1002-31, as that portion of a constituent measured from the filtrate of a water and suspended sediment sample that was first treated with nitric acid to a pH of 2 or less and let stand for 8 to 96 hours prior to sample filtration using a 0.40 or 0.45 -UM (micron) membrane filter. Note the "potentially dissolved" method cannot be used where nitric acid will interfere with the analytical procedure used for the constituent measured. 37. "Practical Quantitation Limit (PQL)" means the minimum concentration of an analyte (substance) that can be measured with a high degree of confidence that the analyte is present at or above that concentration. The use of PQL in this document may refer to those PQLs shown in Part I.E of this permit or the PQLs of an individual laboratory. Appendix C Page 64 of 67 Permit No.: COG500000 38. "Qualified Personnel" for stormwater provisions - those who possess the knowledge and skills to assess conditions and activities that could impact stormwater quality at a facility, and who can also evaluate the effectiveness of control measures. 39. "Quarterly measurement frequency" means samples may be collected at any time during the calendar quarter if a continual discharge occurs. If the discharge is intermittent, then samples shall be collected during the period that discharge occurs. 40. "Recorder" requires the continuous operation of an automatic data retention device for providing required records such as a data logger, a chart and/or totalizer (or drinking water rotor meters or pump hour meters where previously approved.) 41. SAR and Adjusted SAR - The equation for calculation of SAR-adj is: SAR-adj Where: Na+ ++ :,. + Mg 2 Na+= Sodium in the effluent reported in meq/I Mg++= Magnesium in the effluent reported in meq/I Ca.= calcium (in meq/l) in the effluent modified due to the ratio of bicarbonate to calcium The values for sodium (Na+), calcium (Ca++), bicarbonate (HCO3-) and magnesium (Mg++) in this equation are expressed in units of milliequivalents per liter (meq/l). Generally, data for these parameters are reported in terms of mg/I, which must then be converted to calculate the SAR. The conversions are: meq/I = Concentration in mg /l Equivalent weight in nig / meq Where the equivalent weights are determined based on the atomic weight of the element divided by the ion's charge: Na+ = 23.0 mg/meq (atomic weight of 23, charge of 1) Ca++ = 20.0 mg/meq (atomic weight of 40.078, charge of 2) Mg++ = 12.15 mg/meq (atomic weight of 24.3, charge of 2) HCO3- = 61 mg/mep (atomic weight of 61, charge of 1) The EC and the HC03 -/Ca++ ratio in the effluent (calculated by dividing the HCO3 - in meq/I by the Ca++ in meq/l) are used to determine the Ca. using the following table. Table — Modified Calcium Determination for Adjusted Sodium Adsorption Ratio HCO3/Ca Ratio And EC 1, 2, 3 Salinity of Effluent (EC)(dS/m) 0.1 0.2 0.3 0.5 0.7 1.0 1.5 2.0 3.0 4.0 6.0 8.0 Ratio of HCO3/Ca .05 13.20 13.61 13.92 14.40 14.79 15.26 15.91 16.43 17.28 17.97 19.07 19.94 .10 8.31 8.57 8.77 9.07 9.31 9.62 10.02 10.35 10.89 11.32 12.01 12.56 .15 6.34 6.54 6.69 6.92 7.11 7.34 7.65 7.90 8.31 8.64 9.17 9.58 .20 5.24 5.40 5.52 5.71 5.87 6.06 6.31 6.52 6.86 7.13 7.57 7.91 .25 4.51 4.65 4.76 4.92 5.06 5.22 5.44 5.62 5.91 6.15 6.52 6.82 .30 4.00 4.12 I 4.21 I 4.36 I 4.48 4.62 I 4.82 4.98 5.24 5.44 5.77 6.04 .35 3.61 3.72 3.80 3.94 i 4.04 4.17 4.35 4.49 4.72 4.91 5.21 5.45 .40 3.30 3.40 3.48 3.60 3.70 3.82 3.98 4.11 4.32 4.49 4.77 4.98 .45 3.05 3.14 3.22 3.33 3.42 3.53 3.68 3.80 4.00 4.15 4.41 4.61 Appendix C Page 65 of 67 Permit No.: COG500000 . 50 . 75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 3.00 3.50 4.00 4.50 5.00 7.00 10.00 20.00 30.00 2.84 2.93 3.00 3.10 3.19 3.29 3.43 3.54 3.72 3.87 4.11 4.30 2.17 2.24 2.291 2.37 I 2.431 2.51 2.62 2.70 2.84 2.95 3.14 3.28 1.79i 1.85 1.89 1.96 2.01 2.09 1.54 II 1.59 1.63 1.68 1.73 1.78 1.37 1.41 1.44 1.49 1.53 1.58 2.16 1.86 1.65 1.23 1.27 1.30 1.35 1.38 1.43 1.13 1.16 1.19 1.23 1.26 1.31 1.04 1.08 1.10 1.14 1.17 1.21 0.97 1.001 1.02 1.06 1.09 1.12 1.49 1.36 1.26 1.17 2.23 1.92 1.70 1.54 1.40 1.30 2.35 2.02 1.79 1.62 2.44 2.59 2.71 2.10 2.23 2.33 1.86 1.97 2.07 1.68 1.773{ 1.86 1.48 I 1.54 1.63 1.70 1.37 1.42 1.51 1.58 1.21 1.27 1.32 1.40 1.47 0.85 0.89 I 0.91 I 0.94 0.96 I 1.00 I 1.04 1.07! 1.13 I 1.17 1.24 1.30 0.78 0.80 0.82 0.85 0.87 0.90 0.94 0.97 1.02 1.06 1.12 1.17 0.71 0.66 0.61 0.49 0.39 0.24 0.73 0.75 0.78 f 0.80 0.82 0.86 0.88 0.93 0.97 1.03 1.07 0.68 0.69 0.63 0.65 0.72 0.74 0.76 0.79 0.82 0.86 0.67 0.69 r 0.71r 0.74 0.76 0.80 0.90 0.95 0.99 0.83 0.88 0.93 0.50 0.52 0.53 0.55 0.57 0.59 0.61 0.64 0.67 0.71 0.74 0.40 0.41 0.42 0.43 0.45 0.47 0.48 0.51 0.53 0.56 0.58 0.25 0.26 0.26 0.27 0.28 0.29 0.30 0.32 0.33 0.35 0.37 0.18 0.19 0.20 0.20 0.21 0.21 0.22 0.23 0.24 0.25 0.27 0.28 Adapted from Suarez (1981). 2 Assumes a soil source of calcium from lime (CaCO3) or silicates; no precipitation of magnesium, and partial pressure of CO2 near the soil surface (Pco2) is 0.0007 atmospheres. 3 Ca., HCO3, Ca are reported in meq/I; EC is in dS/m (deciSiemens per meter). Because values will not always be quantified at the exact EC or HCO3 /Ca" ratio in the table, the resulting Ca. must be determined based on the closest value to the calculated value. For example, for a calculated EC of 2.45 dS/m, the column for the EC of 2.0 would be used. However, for a calculated EC of 5.1, the corresponding column for the EC of 6.0 would be used. Similarly, for a HCO3-/Ca++ ratio of 25.1, the row for the 30 ratio would be used. The Division acknowledges that some effluents may have electrical conductivity levels that fall outside of this table, and others have bicarbonate to calcium ratios that fall outside this table. For example, some data reflect HCO3-/Ca++ ratios greater than 30 due to bicarbonate concentrations reported greater than 1000 mg/I versus calcium concentrations generally less than 10 mg/I (i.e., corresponding to HCO3 /Ca" ratios greater than 100). Despite these high values exceeding the chart's boundaries, it is noted that the higher the HCO3 /Ca" ratio, the greater the SAR-adj. Thus, using the Ca. values corresponding to the final row containing bicarbonate/calcium ratios of 30, the permittee will actually calculate an SAR-adj that is less than the value calculated if additional rows reflecting HCO3-/Ca" ratios of greater than 100 were added. 42. "Seven (7) day average" means, with the exception of fecal coliform or E. coli bacteria (see geometric mean), the arithmetic mean of all samples collected in a seven (7) consecutive day period. Such seven (7) day averages shall be calculated for all calendar weeks, which are defined as beginning on Sunday and ending on Saturday. If the calendar week overlaps two months (i.e. the Sunday is in one month and the Saturday in the following month), the seven (7) day average calculated for that calendar week shall be associated with the month that contains the Saturday. Samples may not be used for more than one (1) reporting period. (See the "Analytical and Sampling Methods for Monitoring and Reporting Section in Part I.D.3 for guidance on calculating averages and reporting analytical results that are less than the PQL). 43. "Significant spills and leaks" - include, but are not limited to, releases of oil or hazardous substances in excess of quantities that are reportable under CWA Section 311 (see 40 CFR 110.6 and 40 CFR 117.21) or Section 102 of the Comprehensive Environment al Response, Compensation and Liability Act (CERCLA), 42 USC §9602. This permit does not relieve the permittee of the reporting requirements of 40 CFR 110, 40 CFR 117, and 40 CFR 302 relating to spills or other releases of oils or hazardous substances. Appendix C Page 66 of 67 Permit No.: COG500000 44. Significant materials — includes, but is not limited to raw materials; fuels; materials such as solvents, detergents, and plastic pellets; finished materials such as metallic products; raw materials used in food processing or production; hazardous substances designated under Section 101(14) of CERCLA as amended by SARA (1986); any chemical the facility is required to report pursuant to Section 313 of Title III of SARA (1986); fertilizers; pesticides; and waste products such as ashes, slag and sludge that have the potential to be released with stormwater discharges. See 5 CCR 1002-61.2(76). 45. "Stormwater" - stormwater runoff, snow melt runoff, and surface runoff and drainage. See 5 CCR 1002-61.2(103). 46. "Stormwater Discharges Associated with Industrial Activity" - the discharge from any conveyance that is used for collecting and conveying stormwater and which is directly related to manufacturing, processing or raw materials storage areas at an industrial plant. Except for the provision of 61.3(2)(c) that addresses construction activities associated with oil and gas operations or facilities, the term does not include discharges from facilities or activities excluded from the NPDES program under 40 CFR Part 122 or the CDPS program under Regulation No. 61. For the categories of industries identified in this permit, the term includes, but is not limited to, stormwater discharges from industrial plant yards; immediate access roads and rail lines used or traveled by carriers of raw materials, manufactured products, waste material, or by-products used or created by the facility; material handling sites; refuse sites; sites used for the application or disposal of process waste waters); sites used for the storage and maintenance of material handling equipment; sites used for residual treatment, storage, or disposal; shipping and receiving areas; manufacturing buildings; storage areas (including tank farms) for raw materials, and intermediate and final products; and areas where industrial activity has taken place in the past and significant materials remain and are exposed to stormwater. See 5 CCR 1002-61.3(2)(e). 47. "Sufficiently sensitive test procedures": i An analytical method is "sufficiently sensitive" when the method detects and accurately and precisely quantifies the amount of the analyte. In other words there is a valid positive result; or ii. An analytical method is "sufficiently sensitive" when the method accurately and precisely quantifies the result to the AWQC, as demonstrated by the ML is less than or equal to the AWQC. In other words, the level of precision is adequate to inform decision making; or iii. An analytical method is "sufficiently sensitive" when the method achieves the required level of accuracy and precision, as demonstrated by the ML is less than or equal to the PQL. In other words, the most sensitive method is being used and properly followed. 48. "Thirty (30) day average" means, except for fecal coliform or E. coil bacteria (see geometric mean), the arithmetic mean of all samples collected during a thirty (30) consecutive -day period. The permittee shall report the appropriate mean of all self - monitoring sample data collected during the calendar month on the Discharge Monitoring Reports. Samples shall not be used for more than one (1) reporting period. (See the "Analytical and Sampling Methods for Monitoring and Reporting Section in Part I.D.3 for guidance on calculating averages and reporting analytical results that are less than the PQL). 49. "Total Maximum Daily Loads (TMDLs)" - A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. A TMDL includes wasteload allocations (WLAs) for point source discharges; load allocations (LAs) for nonpoint sources and/or natural background, and must include a margin of safety (MOS) and account for seasonal variations. (See section 303(d) of the Clean Water Act and 40 CFR 130.2 and 130.7). 50. "Total Metals" means the concentration of metals determined on an unfiltered sample following vigorous digestion (Section 4.1.3), or the sum of the concentrations of metals in both the dissolved and suspended fractions, as described in Manual of Methods for Chemical Analysis of Water and Wastes, U.S. Environmental Protection Agency, March 1979, or its equivalent. 51. "Total Recoverable Metals" means that portion of a water and suspended sediment sample measured by the total recoverable analytical procedure described in Methods for Chemical Analysis of Water and Wastes, U.S. Environmental Protection Agency, March 1979 or its equivalent. 52. "Toxicity Identification Evaluation (TIE)" is a set of site -specific procedures used to identify the specific chemical(s) causing effluent toxicity. Appendix C Page 67 of 67 Permit No.: COG500000 53. "Toxicity Reduction Evaluation (TRE)" is a site -specific study conducted in a step -wise process to identify the causative agents of effluent toxicity, isolate the source of toxicity, evaluate the effectiveness of toxicity control options, and then confirm the reduction in effluent toxicity after the control measures are put in place. 54. "Twenty four (24) hour composite" sample is a combination of at least eight (8) sample aliquots of at least 100 milliliters, collected at equally spaced intervals during the operating hours of a facility over a twenty-four (24) hour period. For volatile pollutants, aliquots must be combined in the laboratory immediately before analysis. The composite must be flow proportional; either the time interval between each aliquot or the volume of each aliquot must be proportional to either the wastewater or effluent flow at the time of sampling or the total wastewater or effluent flow since the collection of the previous aliquot. Aliquots may be collected manually or automatically. 55. "Twice Monthly" monitoring frequency means that two samples shall be collected each calendar month on separate weeks with at least one full week between the two sample dates. Also, there shall be at least one full week between the second sample of a month and the first sample of the following month. 56. "Visual" observation is observing the discharge to check for the presence of a visible sheen or floating oil. 57. "Water Quality Control Division" or "Division" means the state Water Quality Control Division as established in 25-8-101 et al.) 58. "Water Quality Standards" - means a narrative and/or numeric restriction established by the Commission applied to state surface waters to protect one or more beneficial uses of such waters. Whenever only numeric or only narrative standards are intended, the wording shall specifically designate which is intended. See 5 CCR 1002- 31.5(37). 59. "Wet pit" — generally, a non -navigable waters (frequently a flooded dry pit), from which raw material is extracted using dragline or barge -mounted dredging equipment (hydraulic dredge), both above and below the water table. (40 CFR 436). Additional relevant definitions are found in the Colorado Water Quality Control Act, CRS §§ 25-8-101 et seq., the Colorado Discharge Permit System Regulations, Regulation 61 (5 CCR 1002-61) and other applicable regulations. STATE OF COLORADO COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT Water Quality Control Division COLORADO DISCHARGE PERMIT SYSTEM (CDPS) FACT SHEET TO PERMIT NUMBER COG500000 GENERAL PERMIT FOR DISCHARGES FROM SAND AND GRAVEL MINING AND PROCESSING (AND OTHER NONMETALLIC MINERALS EXCEPT FUEL) Permit Writer - Al Stafford October 13, 2016 TABLE OF CONTENTS I. TYPE OF PERMIT 1 II. FACT SHEET DESCRIPTION 1 III. NEED FOR PERMIT REQUIREMENTS 2 A. Pollutant potential 2 B. Compliance History 3 C. Basis for Determining Permit Terms and Conditions 4 IV. SCOPE OF THE GENERAL PERMIT 6 A. Standard Industrial Classification (SIC) codes and Descriptions of Covered Discharges 6 B. Summary of Major Changes from Last Permit Versions 8 C. Limitations on Coverage 11 V. BASIS FOR MAJOR CHANGES FROM LAST PERMIT VERSIONS 13 A. General 13 B. Process water 14 C. Stormwater 15 VI. DISCUSSION OF PROCESS WATER EFFLUENT LIMITATIONS 25 A. Regulatory Basis for Limitations 25 B. Parameter Evaluation 33 C. Parameter Speciation 36 VII. ADDITIONAL TERMS AND CONDITIONS 36 A. Monitoring 36 B. Reporting 36 C. Spills 37 D. Signatory and Certification Requirements 37 E. Compliance Schedules 37 F. Economic Reasonableness Evaluation 37 VIII. PUBLIC NOTICE COMMENTS - See Appendix B for Division Response to Public Comments document 38 IX. REFERENCES 38 APPENDIX A — Description of Standard Industrial Classification (SIC) Code Major Group 14 facilities 40 APPENDIX B - See Division Response to Public Comments document for Appendix B40 I. TYPE OF PERMIT Master General, NPDES, Surface Water, Sixth Renewal, Statewide. II. FACT SHEET DESCRIPTION This fact sheet addresses the following statutory and regulatory requirements: • A permit "rationale" as required by Colorado Discharge Permit System Regulations, 5-CCR-61.5(2) • A "preliminary analysis" as required by Colorado Water Quality Control Act, C.R.S. 25-8-502(3)(b) COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 2, Permit No. COGS00000 • A "statement of basis and purpose" as required by the federal Discharge Permit Regulations, 40 CFR 124.7, to "describe the derivation of permit conditions and the reasons" • A "fact sheet" as required by the federal Discharge Permit Regulations 40 CFR 124.8 and 124.56 to "briefly set forth the principal facts and the significant factual, legal, methodological and policy questions considered in preparing the draft permit. describe the reason" for permit terms and conditions • A "statement of basis and purpose" as required by SB 13-073 and incorporated into Colorado Water Quality Control Act, C.R.S. 25-8-503.5, "explaining the need for the proposed requirements" and to "present evidence supporting the need for the proposed requirements, including information regarding pollutant potential and available controls, incidents of environmental damage, and permit violations" III. NEED FOR PERMIT REQUIREMENTS This section includes factors explaining the need for the proposed requirements and presents evidence supporting the need for the proposed requirements, including information regarding pollutant potential and available controls, incidents of environmental damage, and permit violations. The Division has also included some background information to provide context for the statutory and regulatory direction as to how permit terms and conditions are established. A. Pollutant potential Sand and Gravel The Development Document for Effluent Limitations Guidelines and Standards for the Mineral Mining and Processing Industry Point Source Category (EPA 440/1-76/059b, July 1979) provides the supporting data and rationale for development of the ELGs and standards of performance for this point source category (i.e., 40 CFR Part 436). For the facilities that are eligible to discharge under the final permit, the major waste water pollutant parameters identified in the development document include total suspended solids, dissolved solids, iron, zinc, fluoride and pH. Note that a number of additional pollutant parameters were studied, including metals, temperature, asbestos, and radium 226, but were not found to be significant at the time the development document was published. Further, EPA documented the pollutants that are typically associated with sand and gravel mining operations in the federal register with the issue of the 1995 MSGP (60 Federal Register 189, p. 50919. September 29, 1995). For most activities, such as site preparation, mineral extraction, mineral processing, and reclamation, typical pollutants included dust, total suspended solids, total dissolved solids, and turbidity. EPA also identified the potential for pollution from oil and fuel, and other toxic contaminants, such as metals, benzene, trichloroethane, tetrachloroethylene, polyaromatic hydrocarbons, and solvents from equipment and vehicle maintenance, as well as nitrogen and phosphorus from any fertilizer used in reclamation activities. In 2006, EPA issued an industrial stormwater factsheet series and identified the pollutants that may be present in stormwater discharges from sand and gravel operations and Best Management Practices (BMPs) to control these pollutants (US Environmental Protection Agency. EPA -833-F-06-025, Dec. 2006). The pollutants identified in the 1995 FR were also identified in the 2006 fact sheet. With respect to selenium, numerous peer -reviewed articles on the environmental impacts of high selenium levels on aquatic life have been published. Many of these studies are cited in the January, 2011 TMDL. (See, i.e., Ohlendorf, et.al., 1986, 1988). These studies, and the potential impacts to aquatic species from selenium, were considered as part of the development process for the TMDL. Currently EPA is reviewing the Aquatic Life criterion for selenium. 79 FR 27601-27604. Once finalized, EPA's revised water quality criterion for selenium will provide recommendations to states and tribes authorized to establish water quality standards under the Clean Water Act. Asphalt Batch Plants EPA documented the pollutants typically associated with stormwater discharges from asphalt paving manufacturing facilities, which includes asphalt batch plants, in the federal register with the issue of the 1995 MSGP (60 Federal COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 3, Permit No. COG500000 Register 189, p. 50861 and 50862. September 29, 1995). For material storage and handling activities, typical pollutants included total suspended solids, oil and grease, pH and chemical oxygen demand (COD). In addition, the 2006 industrial factsheet series issued by EPA for Asphalt Paving and Roofing Materials Manufacturers and Lubricant Manufacturers (US Environmental Protection Agency. EPA -833-F-06-019, Dec. 2006) identifies the pollutants that may be present in stormwater discharges from these industrial activities, which includes asphalt batch plants. This factsheet expands the list of pollutants identified in the 1995 FR to also include total dissolved solids (TDS), biochemical oxygen demand (BOD), benzene, methylene blue active substances (MBAS), and metals. Concrete Batch Plants EPA documented the pollutants that are typically associated with concrete mixing operations in the federal register with the issue of the 1995 MSGP (60 Federal Register 189, p. 50869 and 50870. September 29, 1995). For concrete mixing activities, typical pollutants included TSS, pH, COD, lead, iron and zinc. At facilities that also conduct equipment/vehicle fueling and maintenance, additional potential pollutants included oil and grease, BOD, lead, aluminum, arsenic, cadmium, chromium, and benzene. In 2006, EPA issued an industrial stormwater factsheet series and identified the pollutants that may be present in stormwater discharges from concrete manufacturing operations and BMPs to control these pollutants (US Environmental Protection Agency. EPA -833-F-06-020, Dec. 2006). The pollutants identified in the 2006 factsheet included TSS, pH, COD, lead, iron, zinc, oil and grease, BOD. B. Compliance History The Division reviewed indicators of permit compliance for general permits COG500000 and COR340000 as part of the renewal process. The Division reviewed Discharge Monitoring Report (DMR) data for general permit COG500000, and obtained input from Division inspectors who conduct field -based assessments of compliance for both COG500000 and COR340000 general permits. DMR data The Division reviewed DMR data for approximately 160 facilities authorized under COG500000 from 2008 through 2013. Overall, facilities reported "no discharge" conditions approximately 70% of the time, and failed to submit DMRs approximately 6% of the time. The Division observed that sampling data accuracy was hindered by incorrect data entry or unit conversions in a number of instances. All facilities were required to monitor or sample for discharge flow, total suspended solids, oil and grease, and pH. The Division made the following observations for these parameters: • Flow: 65% of the reported flows were less than one million gallons per day; an additional 32% were between one and ten million gallons per day. • Total suspended solids: The data revealed that there was a 1.9% exceedance rate of the 30 day average effluent limitation. • Oil and grease: Many facilities entered observations incorrectly and were unclear on the need for sampling; however, of the samples analyzed, none displayed exceedances of the daily maximum effluent limitation. • pH: a total of 0.5% of the samples values fell outside of the limitation range. Facilities discharging to the Colorado River Basin were required to monitor for total dissolved solids (TDS) — the mean 30 day average was 1,742 mg/I, with concentrations ranging from zero to 13,160 mg/I. This wide range indicates that TDS discharge concentrations are site specific and vary depending on current site activity. A total of 19 facilities were required to sample for total recoverable iron — 0.5% of the samples exceeded the 30 day average limitation. One facility sampled for manganese — the 30 day average data displayed a wide range from 5- 915 µg/I. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 4, Permit No. COGS00000 Ten facilities were required to sample for phosphorus, but all facilities either did not submit data or observed "no discharge" conditions during all monitoring periods. Two facilities were required to sample for sulfate — twenty total samples were analyzed, and concentrations ranged from 240-551 mg/I. While no selenium limitations were applied in the permit certifications, a total of 54 facilities were required to sample for selenium. A total of 444 samples were analyzed, the mean 30 day average concentration was 6.2 µg/I, and the median concentration was 1.0 µg/I. The data indicates a 30% exceedance rate of the 30 day average chronic water quality standard of 4.6 µg/I. Field -based Compliance Assessments Input from Division inspectors who conduct field -based compliance assessments for the general permits indicate that some existing permit conditions are not sufficiently clear to enable a compliance determination in the field. Examples include variable monitoring frequency (weekly vs. 2 days/month), continuous vs. instantaneous flow measurement, applicability of monitoring to stormwater discharges, etc. The Division clarified these requirements in this renewal. Input also indicated that other agency requirements (e.g., Division of Reclamation, Mining and Safety and Mine Safety and Health Administration) and site topography/grading practices may benefit permittees with respect to permit compliance. For example, safety berm requirements can serve as an effective perimeter berm BMP; facility grading that directs stormwater to the mine pit can minimize the need for erosion/sediment control BMPs. However, Division inspectors commonly observed deficiencies during field -based compliance assessments, which include: • DMR forms not sent to the Division; or DMR information not reported appropriately (units not reported in correct columns; oil and grease not reported properly); • Non -detects results not averaged appropriately; units not reported correctly; or conversion from laboratory report units to permit required units not done correctly; • Flow measured as instantaneous instead of continuous. • Stormwater Management Plan (SWMP) deficiencies; • Comprehensive inspections deficient or not conducted; • Annual reports deficient and not signed by appropriate personnel; • Inadequate secondary containment (lack of good housekeeping); • Equipment leaks, drip, spills (lack of spill response BMPs); • Installation details for BMPs implemented in field not included in SWMP; • Access road BMP deficiencies, including vehicle tracking. The Division used this information to structure some of the changes and clarifications made to the permit, as discussed in Part III.C and Part V of this Fact Sheet. C. Basis for Determining Permit Terms and Conditions The Division develops permit terms and conditions as directed through federal and state statutes and implementing regulations as summarized below. Congress created the National Pollutant Discharge Elimination System (NPDES) permit program through enactment of the Federal Water Pollution Control Act (FWPCA) Amendments of 1972. This followed a period of previous water quality legislation where Congress had authorized states to develop water quality standards that were intended to limit discharges of pollutants based on the individual characteristics of waterbodies. The FWPCA Amendments of 1972 introduced the NPDES program including the requirement to include technology -based requirements to address a concern about a lack of progress in water quality protection and a lack of enforceability in previous legislation. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 5, Permit No. COG500000 The FWPCA Amendments contained four important principles related to the NPDES program as summarized by EPA: 1. The discharge of pollutants to navigable waters is not a right. 2. A discharge permit is required to use public resources for waste disposal and limits the amount of pollutants that may be discharged. 3. Wastewater must be treated with the best treatment technology economically achievable, regardless of the condition of the receiving water. 4. Effluent limits must be based on treatment technology performance, but more stringent limits may be imposed if the technology -based limits do not prevent violations of water quality standards in the receiving water. The NPDES permit was created by Congress as the implementation tool for restriction of the quantity, rate, and concentration of pollutants that the point sources may discharge into water. The Division, as the delegated authority for development and issuance of NPDES permit for the state of Colorado, is obligated to develop and issue NDPES permits in a manner that meets both state and federal statutory and regulatory requirements. Routine review is an integral aspect of the NPDES program. Congress's expectation is that permits remain current in their ability to incorporate advancements in science and technology, law, and be reflective of current industrial operations resulting in a discharge of pollutants to waters. The Division must renew general permits once every 5 years, and must include such conditions in the renewal permit that are necessary to implement statutory and regulatory provisions. This comprehensive permit renewal results from the Division's review of the sand and gravel stormwater and process water permits, which identified differences in the existing permits relative to EPA's MSGP, other state permits, case law, and statutory and regulatory direction provided. EPA summarizes the major steps for development and issuance of NPDES permits, as required by 40 CFR §124, as follows: 1. Receive application from permittee. 2. Review application for completeness and accuracy. 3. Request additional information as necessary. 4. Develop technology -based effluent limits using application data and other sources. 5. Develop water quality -based effluent limits using application data and other sources. 6. Compare water quality -based effluent limits with technology -based effluent limits and choose the more stringent of the two as the effluent limits for the permit. 7. Develop monitoring requirements for each pollutant. 8. Develop special conditions. 9. Develop standard conditions. 10. Consider variances and other applicable regulations. 11. Prepare the fact sheet, summarizing the principal facts and the significant factual legal, methodological and policy questions considered in preparing the draft permit including public notice of the draft permit, and other supporting documentation. 12. Complete the review and issuance process. 13. Issue the final permit. 14. Ensure permit requirements are implemented. During the development of this permit, the Division received a number of comments suggesting that the Division perform a cost -benefit analysis to justify the changes in terms and conditions, specifically monitoring and recordkeeping requirements and effluent limitations. Neither the Colorado Water Quality Control Act and the Colorado Discharge Permit Regulations (5 CCR 61) nor the federal Clean Water Act, and federal discharge permit regulations (40 CFR 122, 124, etc), require a formal monetized cost benefit analyses for development of permit terms and conditions, where every dollar spent on pollution control, monitoring, and recordkeeping must return at least a dollar in enhanced water quality. Rather, the Division develops permit terms and conditions as directed through federal and state statutes and implementing regulations with key thresholds for decision making as COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 6, Permit No. COG500000 summarized below. All NPDES permits are required to contain technology -based limitations. [see 40 CFR §§122.44(a)(1) and 125.3. CWA sections 301(b)(1)(A) for (BPT); 301(b)(2)(A) for (BAT); and 301(b)(2)(E) for (BCT).] The Division developed technology based effluent limits consistent with the federal requirements cited above, and state requirements such as those contained in 5 CCR 1002-62. The Division also found in this case that more stringent limits must be imposed for some discharges, specifically those discharging to impaired waterbodies consistent with the assumptions and requirements of TMDLs. Additional information regarding the derivation and establishment of effluent limits is contained in this fact sheet. All NPDES permits are required to contain monitoring requirements. Federal and state permitting regulations require that at a minimum permits specify monitoring requirements for each pollutant limited in the permit, and for industrial stormwater permits, specify on -site inspection requirements. Permits must specify monitoring equipment, methods, intervals, and frequencies sufficient to yield data which are representative of the monitoring activity and must specify the content of records to be maintained, and records retention requirements. The state discharge permit regulations establish a threshold of "reasonableness" in directing the derivation of monitoring and recordkeeping requirements. For development of this permit the Division determined the monitoring and records logically needed to meet the threshold of representative of the monitoring activity, demonstrate that the monitoring was adequately performed, document the conditions surrounding the event and what was observed, and document findings and actions taken, while not including superfluous requirements. IV. SCOPE OF THE GENERAL PERMIT Two CDPS general permits currently exist (see table below) related to sand and gravel or other non-metallic mineral mining and processing facilities (except fuel), hereafter referred to as 'sand and gravel facilities' in this fact sheet. The COG500000 general permit authorized both process water and stormwater discharges; the COR340000 general permit authorizes stormwater-only discharges. Together these general permits provide coverage for discharges from approximately 660 sand and gravel facilities across the state. Both permits were administratively extended to provide ongoing permit coverage until the renewal was complete. This renewal master general permit is necessary to provide continued coverage for these existing discharges, and for new discharges from sand and gravel facilities. Permit name and number Effective date Expiration date Sand Except & Gravel Fuel) (COG500000) Mining and Processing (And Other Nonmetallic Minerals, July 1, 2008 June 30, 2013 Stormwater Processing (And Discharges Other Nonmetallic Associated with Minerals, Sand & Gravel Except Fuel) Mining (COR340000) and October 2007 1, September 30, 2012 This renewal master general permit (permit) combines the two general permits referenced above. The Division determined that combining the two existing general permits will result in a more comprehensive permitting approach; consistency of permit requirements; clearly defined termination requirements; and a more efficient renewal process. A. Standard Industrial Classification (SIC) codes and Descriptions of Covered Discharges This permit authorizes the discharge of process water and stormwater runoff to surface waters of the state, from active and inactive eligible facilities engaged in mining and processing of sand and gravel (and other nonmetallic minerals, except fuel). Such facilities are generally described by Standard Industrial Classification (SIC) Code Major Group 14. This permit also authorizes the discharge of stormwater runoff to surface waters of the state from the following non -mining activities that are located at sand and gravel facilities: asphalt batch plants (SIC code 2951), concrete batch plants (SIC Code 3273), and asphalt and concrete recycling industrial activities. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 7, Permit No. COGS00000 The public notice version of the permit did not authorize the non -mining discharges described above, opting to authorize them through alternate permits and focus the renewal permit solely on mining activities. However, after considering the stakeholder comments received on this proposed approach during the public notice period, and further weighing the associated advantages and disadvantages of authorizing discharges from the non -mining activities, the division ultimately decided to include coverage for stormwater discharges from asphalt batch plants (SIC code 2951); stormwater discharges from concrete batch plants (SIC code 3273); and stormwater discharges from asphalt and concrete recycling activities in final permit COG500000 (see response to Comment ID COG50-2.2 and COG50-5.3). Note that the term `asphalt batch plant' (2951 SIC code) as used in the renewal permit documents refers to the manufacturing plant that combines aggregate and an asphalt binder to produce asphalt concrete. Asphalt concrete is known by many different names, such as hot mix asphalt, plant mix, bituminous mix, bituminous concrete, etc. The division is using the term `asphalt batch plant' instead of `asphalt concrete batch plant' to avoid any confusion with concrete batch plants (3273 SIC code), and for consistency with other CDPS permits. The final permit clarifies the types of discharges that are eligible for permit coverage, as follows: 1. Process water discharges from facilities that produce the following commodities. • Dimension stone (SIC code 1411) • Crushed stone (SIC code 1422, 1423, 1429) • Construction sand and gravel (SIC code 1442) • Industrial sand (SIC code 1446) • Kaolin and Ball Clay (SIC code 1455) • Clay, Ceramic, and Refractory Minerals, Not Elsewhere Classified (SIC code 1459) • Graphite (SIC code 1499) This list includes all commodities identified in the applicable federal Effluent Limitation Guideline [40 CFR Part 436 (Mineral Mining and Processing Point Source Category)] for which a facility discharge is allowed. The list also includes facilities that produce Dimension stone, Kaolin and Ball Clay, and Clay, Ceramic, and Refractory Minerals, as the Division has permitted discharges from such facilities in the past. The list does not include those subparts that require `no discharge' of process generated wastewater, as discussed in the Limitations on Coverage section of this fact sheet. APPENDIX A of this fact sheet provides a description of each SIC code identified above. The following process water discharges from the facilities identified in this section are eligible for permit coverage. a. mine dewatering, which includes: i. any water, including groundwater, seepage, and stormwater (precipitation and surface runoff), that is impounded or that collects in the mine pit (surface or underground workings) and is pumped, drained, or otherwise removed from the mine through the efforts of the mine operator; ii. additionally, for construction sand and gravel facilities and industrial sand facilities only, wet pit* overflow caused solely by direct rainfall and/or groundwater seepage. b. process generated wastewater, which includes any wastewater used in slurry transport of mined materials, air emissions control, and processing exclusive to mining (40 CFR Part 436); c. water used in sand and gravel processing (e.g., sorting, screening, crushing, and classifying); d. stormwater runoff that becomes comingled with the above listed wastewaters before the discharge point. * The division also provided a definition for "wet pit", consistent with the development document for the federal ELG (40 CFR 436), as a non -navigable water (frequently from a flooded dry pit) from which raw COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 8, Permit No. COGS00000 material is extracted using dragline or barge -mounted dredging equipment (hydraulic dredge), both above and below the water table. 2. Stormwater discharges from the areas identified below, at active and inactive SIC code Major Group 14 facilities, including those from asphalt and concrete batch plants (SIC codes 2951 and 3273), and from asphalt and concrete recycling activities. Note that the final permit does not include stormwater discharges from refuse sites; sites used for the application or disposal of process waste waters; and sites used for residual treatment, storage, or disposal as stormwater discharges from these activities are not included in the eligibility scope of the permit. For example, sand and gravel facilities that have a concurrent or post - mine land use as a landfill must obtain CDPS stormwater discharge permit coverage separate from this permit. a. industrial plant yards; b. immediate access roads and rail lines used or traveled by carriers of raw materials, manufactured products, waste material, or by-products used or created by the facility; c. material handling sites, including those used for asphalt and concrete recycling activities, asphalt batch plants, and concrete batch plants; d. sites used for storage and maintenance of material handling equipment; e. shipping and receiving areas; f. manufacturing buildings, including asphalt batch plants and concrete batch plants; g. storage areas and stockpiles of raw material, intermediate products, byproducts, finished products or waste products (including topsoil, overburden, and materials associated with asphalt and concrete recycling activities, asphalt batch plants, and concrete batch plants); h. areas where industrial activity has taken place in the past and significant materials remain and are exposed to stormwater; i. all disturbed areas (other than those subject to the process water discharge provisions above), including mine pit out slopes; and, j. stormwater run-on that commingles with stormwater discharges associated with sand and gravel mining and processing. 3. Allowable non-stormwater discharges as described in this part, provided that appropriate control measures are implemented to minimize erosion and sediment transport resulting from such discharges, and the non- stormwater component(s) of the discharge and the control measure(s) used are identified in the Stormwater Management Plan (SWMP). Note that in the final permit, the division clarified that `uncontaminated condensate' as an allowable non-stormwater discharge refers to external atmospheric condensation only. a. Uncontaminated condensate (external atmospheric condensation, only) from air conditioners, coolers, and other compressors and from the outside storage of refrigerated gases or liquids; b. Landscape (including reclamation activities) watering provided all pesticides, herbicides, and fertilizer have been applied in accordance with the approved labeling; c. Incidental windblown mist from cooling towers that collects on rooftops or adjacent portions of the facility, but not intentional discharges from the cooling tower (e.g., "piped" cooling tower blow down or drains); and B. Summary of Major Changes from Last Permit Versions With respect to process water discharges eligible for coverage under the renewal permit, the Division made changes to the permit to clarify and update effluent limitations and other terms and conditions, consistent with regulatory COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 9, Permit No. COG500000 requirements and direction, and Division practice. This fact sheet addresses these changes, and an updated evaluation of parameters has been added. With respect to stormwater discharges eligible for coverage under this renewal permit, the Division's approach was consistent with that taken for general permit COR900000 (Stormwater Discharges Associated with Non -Extractive Industrial Activity). Specifically, the Division evaluated the effluent limitations, and terms and conditions contained in EPA's 2008 and 2015 MSGPs related to sand and gravel industrial activities, and the associated basis for each provided in the Fact Sheets. The Fact Sheets for the MSGPs provide detailed background and basis for the organization, scope and content of those permits; these documents are available on EPA's website. In this fact sheet, the Division has documented where terms and conditions in this permit are consistent with the MSGPs. Pre -Public Notice stakeholder meeting As part of the renewal of the existing general permits, the Division conducted a stakeholder process that included a Pre -Public Notice Meeting on February 28, 2014. The purpose of the stakeholder meeting was to increase awareness of the renewal process for the general permit, discuss the substantive areas of review, and obtain input for developing draft permit conditions. The Division considered the stakeholder input received during the meeting, and written input received after the meeting. The division considered the stakeholder input in developing draft permit conditions, and balanced these comments with regulatory and environmental obligations. Major stakeholder input that was submitted is detailed below: 1. Within the stakeholder process, the Division sought guidance on whether the former COG500000 and COR340000 permits should be combined into one permit that authorizes both stormwater and process water discharges. Permittees responded positively to this proposal, so long as the Division made the difference in permit requirements for stormwater and process water discharges very clear. The Division consequently has combined the two permits, and has clearly labeled throughout the permit sections that apply only to stormwater or only to process water discharges. The Division also provided a general overview at the beginning of the permit, which specifies which sections apply to only one type of discharge. 2. Stakeholders expressed concern regarding requiring benchmark sampling for stormwater discharge only facilities due to burden and the capacity of Practice Based Effluent Limitations to minimize pollutants of concern from discharging from the site. As noted further within this Fact Sheet, the Division has determined that benchmark sampling will not be required for stormwater discharges from SIC code Major Group 14 activities, and instead visual monitoring will be required, as further described below. 3. The Division also addresses within this Fact Sheet stakeholder concerns regarding unstaffed and remote sites. The Division acknowledges the burden in sampling at inactive and unstaffed sites (whether they are remote or not), and therefore did not require visual monitoring at such facilities. However, some level of monitoring must be maintained to continue to ensure a low pollutant potential, and therefore an increased inspection frequency is included in the permit for these sites. 4. An issue of high input within the industry was the implementation of the selenium TMDL for the Gunnison River and tributaries, as well as selenium monitoring on impaired segments. Implementation for these situations is further addressed within this fact sheet, which takes into account the input of the permittees as well as the assumptions and requirements of the established TMDL. Intake credits are also discussed in response to stakeholder comments regarding this topic. Summary of Major Changes from the Last Permit Versions that were contained in the Draft Permit This fact sheet provides a description of the major and significant changes from the existing sand and gravel stormwater discharge permit (COR340000) and process water discharge permit (COG500000). A summary of the major changes from the previous permits are provided below; Part V of this fact sheet provides further detail, including additional basis for the changes, where warranted. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 10, Permit No. COG500000 General • The Division added a new section entitled Allowable Non-Stormwater Discharges to the renewal permit to identify all allowable non-stormwater discharges, including those not specific to this sector. The Division added this section to clarify the scope of the renewal permit. • The renewal permit clarifies the administrative aspects of permit coverage (i.e., Application Requirements, Permit Certification Procedures, Alternative permits, Permit Expiration and Continuation, Transfer of permit coverage, Modifying an existing permit, and Permit Termination Procedures), and includes clear direction for permittees to change permit coverage from one that authorizes both process water and stormwater, to stormwater-only permit coverage. • The Division added a new section entitled Permit Compliance to the renewal permit to clarify conditions that constitute a violation of the permit (e.g., failure to comply with the terms and conditions of the permit; failure to perform corrective actions, etc.). This section also clarifies that correcting a permit violation does n ot remove the original violation. Process water • Discharges from facilities that produce Phosphate rock (SIC code 1475) are no longer eligible for coverage u nder this permit. • Process water discharges from asphalt batch plants are no longer eligible for coverage under this permit. • Process water discharges from concrete batch plants, including wash water discharges from associated trucks and drums are no longer eligible for coverage under this permit. • Flow limitations were added to the effluent limitations tables. • Effluent limits for selenium were derived for discharges to the Gunnison River and tributaries, consistent with the assumptions and requirements of the TMDL. Stormwater Many of the provisions applicable to stormwater in the renewal permit are consistent with CDPS general permit COR900000. Changes the division made to the final permit resulting from public comments are provided following the original list. • The Division modified the self -inspection requirements in the renewal permit. Most significant among the changes are inspection frequency (i.e., quarterly inspections); inspection scope (i.e., one inspection must be conducted during a run-off event); modified inspection frequency for inactive and unstaffed facilities (6 per year); and corrective action requirements. • The Stormwater Discharge Effluent Limitations contained in this permit are located in a section separate from the Stormwater Management Plan (SWMP), thereby differentiating effluent limitations from other terms and conditions of the permit. • The Division modified the practice -based effluent limitations required by this permit from those required u nder permits COG500000 and COR340000. Most significant among the changes are including the term "minimize" within the practice -based effluent limitations, and adding several new practice -based effluent limitations. • The Division added a new section (Water Quality Based Effluent Limitations) that addresses water quality - based effluent limitations (WQBELs) applicable to stormwater discharges. • The Division consolidated and clarified monitoring requirements for stormwater discharges in the General Monitoring Requirements - Stormwater Only section of the renewal permit. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 11, Permit No. COG500000 • The Division added a new section (Specific Monitoring Requirements - Stormwater Only), that addresses requirements for Visual Monitoring, and Water Quality Standards monitoring requirements as applicable to the facility. • The Division added a new section (Corrective Actions) that identifies permittee responsibilities with respect to resolving specific facility conditions. Summary of Major Changes from the Draft Permit to the Final Permit The division solicited input on the draft permit conditions, specifically for situations where reviewers found that the information presented in the draft permit, upon which the Division relied to make draft decisions, was incomplete; and on the specific permit language. The final permit contains permit conditions based on the best information available to inform decisions for Colorado, and incorporates additional information received on these topics during public notice, as appropriate. The final permit contains the following new or modified provisions. Please see the Division Response to Public Comments for a discussion of these changes. • The division added flexibility to the self -inspection requirements in the permit by adding an exception to the annual runoff event inspection for Completed and Finally Stabilized Areas. • The division added coverage for stormwater discharges from asphalt batch plants (SIC code 2951), stormwater discharges from concrete batch plants (SIC code 3273), and stormwater discharges from asphalt and concrete recycling activities in final permit COG500000. • The division modified the Specific Monitoring Requirements - Stormwater Only section, to add Benchmark Monitoring requirements for Asphalt Batch Plants and Concrete Batch Plants, as applicable to the facility, and added Sector -Specific Requirements for Asphalt Batch Plants and Concrete Batch Plants at Parts 1.O and I.P, respectively. • The division added definitions to the permit (Appendix C) to clarify the meaning of `inactive' for this permit, which broadens the applicability of the monitoring exceptions for inactive and unstaffed sites, and to clarify the terms wet pit, asphalt batch plant, and asphalt concrete as used in this permit. • The division added new monitoring exceptions for Completed and Finally Stabilized Areas. • The division added a new provision that allows the division to revoke any monitoring exception. • The division added requirements regarding EPA's Net-DMR submittal. C. Limitations on Coverage This section of the fact sheet identifies those discharges from sand and gravel facilities that are specifically excluded from permit coverage. Permittees may seek individual or alternate general permit coverage for such discharges, as appropriate and available. After public notice, the division added a limitation of coverage for discharges from placer mining activities (SIC Major Group 10) to clarify that the scope the permit, like the previous permit, does not authorize discharges from placer mining activities. The division further clarified the requirement to obtain permit coverage under the Construction stormwater permit (general permit COR030000) in this fact sheet (see below). In addition, the division removed the limitation for process water discharges from `major' facilities, as determined by the NPDES Permit Rating Work Sheet. The following list of limitations incorporates these changes. Please see the Division Response to Public Comments for a discussion of these changes. • Stormwater discharges associated with construction activity that disturbs one acre or more are excluded from coverage. Consistent with Division practice, construction activity does not include land disturbance resulting from the act of mining, such as removal of topsoil and overburden to expose mineable minerals, or the COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 12, Permit No. COG500000 extraction, removal or recovery of minerals. Construction activity does include construction of facilities necessary to conduct mining activities, including but not limited to haul roads, pads, structures, etc. The Division considered including these construction activities (those that exceed one -acre of disturbance) as an industrial activity authorized under this renewal permit. However, the Division determined that because an ELG has been promulgated by EPA for the construction and development category (Effluent Limitations Guidelines and Standards for the Construction and Development Point Source Category, 40 CFR Part 450), it was more appropriate to interpret the ELG during renewal of the CDPS stormwater construction permit (COR030000). In addition, the Division finds it most efficient, for general permits, to have a specific type of discharge authorized in just one general permit rather than multiple general permits. For these reasons, the Division decided against providing coverage for construction activities in this renewal permit. Therefore, stormwater discharges from construction of haul road, pad, structure, etc. at sand and gravel facilities, that exceeds the one -acre threshold and that do not commingle with process water from the facility (see discussion on Commingled discharges below), must be covered by a separate stormwater construction permit certification. • Commingled discharges: The division considers stormwater runoff (from industrial or construction activities) that combines with process water (such as water in the mine pit), to be process water. Such discharges are subject to the process water provisions in the permit, and the stormwater provisions do not apply. This approach also applies to stormwater runoff from construction activities at the facility that exceed the one -acre threshold; specifically, if run-off from such activities commingles with facility process water, the commingled discharge is subject to the process water provisions in the permit, and the activity does not require separate construction stormwater permit coverage. • Discharges to outstanding waters are excluded because the Division requires such discharges to be authorized by an individual permit to fulfill the antidegradation requirements of Regulation 31 -The Basic Standards and Methodologies for Surface Water. • Discharges solely to ground water are excluded water if such discharges are subject to direct regulation by implementing agencies under Section 25-8-202(7) of the Water Quality Control Act or Senate Bill 181. At mining facilities, discharges solely to ground water fall under the jurisdiction of the Division of Reclamation, Mining and Safety. This exclusion does not apply to point source discharges of pollutants to groundwater in direct hydrologic connection to surface waters and for which the Division determines the surface waters requirements of Regulation 61 apply, such as for some discharges to groundwater in alluvial areas. • Discharges currently covered by another permit or a Division Low Risk Guidance Document are excluded. As stated in the Low Risk Policy, the Division does not intend to provide general permit coverage for discharges covered by a Low Risk Guidance Document. • Discharges with chemical additions (including release agents) are not authorized unless expressly approved by the Division, and the Division provides notification of such approval to the permittee. A release agent is a substance used to aid in the separation of the desired material from the substrate, and must be disclosed. Part I.A.3 of the permit provides the process and information required to request Division approval of a specific chemical. If authorized, all chemicals must be used and stored in accordance with the manufacturers' recommendations and in accordance with any applicable state or federal regulation. On a case -by -case basis, the Division may determine that some discharges with chemical addition require individual permit coverage, such as if the specific chemical proposed contains constituents of concern that requires a more extensive reasonable potential analysis, or if dilution is required to meet applicable water quality standards in the receiving water. • Process water discharges from the facilities listed below are excluded from coverage due to the potential toxicity and wide variety of pollutants, the minimal operations in Colorado, or Federal ELGs that require no discharge of process water from these facilities: COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 13, Permit No. COG500000 no Facility discharge types of that process require water 40 CFR Subpart 436 SIC Code Gypsum air emissions facilities that control do scrubbers not employ wet E 1499 Asphaltic mineral facilities F 1499 Asbestos and wollastonite facilities G 1499 Barite wet processes facilities that or flotation do not employ processes J 1479 Flourspar media separation facilities that or flotation do not employ processes heavy K 1479 Saline from brine lake facilities L 2899 Borax facilities M 1474 Potash facilities N 1474 Sodium sulfate facilities O 1474 Phosphate Rock R 1475 Frasch sulfur facilities S 1479 Bentonite facilities V 1459 Magnesite facilities W 1459 Diatomite facilities X 1499 Jade facilities Y 1499 Novaculite facilities Z 1499 Tripoli facilities AF 1499 Asphalt batch plants 40 CFR 443 2951 Concrete drum wash batch out plants, including associated truck and --- 3273 V. BASIS FOR MAJOR CHANGES FROM LAST PERMIT VERSIONS A. General 1. Termination criteria The permit identifies the process by which the permittee can inactivate permit coverage, and the mandatory termination conditions for sand and gravel facilities that have a Division of Reclamation, Mining and Safety (DRMS) financial and performance warranty, and those that do not. Termination of permit coverage requires that 'all permitted process water discharges authorized by this permit ... have ceased'. This requirement applies specifically to the discharge authorized by the Water Quality Control Division. While this discharge remains, the permit certification cannot be terminated. In some cases, the post -mining land -use for the sand and gravel pit is identified as a pond (such as for livestock watering, recreation purposes, etc.), and occasionally, the pond will discharge due to localized hydrology, etc. In such cases, when the post -mining land -use is achieved, the Division does not require continued permit coverage for discharges from the pond, for the following reasons. • The post -mining land -use pond no longer meets the definition of a `mine' — As provided in the effluent limitation guidelines found at 40 CFR Part 436 (Mineral Mining and Processing Point Source Category), COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 14, Permit No. COG500000 the term 'mine' means an area of land, surface or underground, actively mined for the production of [commodity] from natural deposits. • The pond discharge does not meet the definition of 'mine dewatering' — As provided in the effluent limitation guidelines found at 40 CFR Part 436, 'mine dewatering' includes any water, including groundwater and stormwater, that is impounded or that collects in the mine and is pumped, drained, or otherwise removed from the mine through the efforts of the mine operator. Because the post -mining land -use pond is no longer a mine, and therefore, the pond discharge is not mine dewatering, the Division determined that continued permit coverage for any discharge from the pond is not required. Note that termination is contingent on the permittee demonstrating to the Division that DRMS approved the applicable financial and performance warranty release, or alternatively, that the facility meets the final stabilization criteria established in the permit. This termination approach is a long-standing Division practice for sand and gravel facilities with a post -mining land -use as described above. The Division added the specific termination criteria in the permit and the associated discussion in the fact sheet to facilitate public comment and improve transparency and certainty. 2. Electronic reporting of data The final permit includes requirements regarding EPA's Net-DMR submittal, and dates when permittees must start reporting data electronically. Prior to December 21, 2016, the permittee may elect to electronically submit DMRs instead of mailing paper DMRs by using the EPA's Net-DMR service. Starting on December 21, 2016, the permittee must electronically report DMRs by using the EPA's Net-DMR service unless a waiver is granted in compliance with 40 CFR 127. B. Process water This section provides the basis for major changes to the process water provisions from the previous permit versions. The discussion of process water effluent limitations is at Section VI of this fact sheet. Note that after public notice, the division made the following changes to the final permit: • removed the limitation for process water discharges from 'major' facilities, and such facilities are now e ligible for coverage under the final permit, and • removed the discussion regarding facilities that produce asphalt emulsion from the fact sheet, as it is u nlikely that this manufacturing industrial activity occurs at mining facilities in Colorado. The following list incorporates changes to the final permit resulting from the division's review of comments received during the public notice period. Please see the Division Response to Public Comments for a discussion of these changes. 1. Process water discharges from Dimension stone; Kaolin and Ball Clay; and Clay, Ceramic, and Refractory Minerals The Division clarified the types of facilities that are eligible for coverage under the permit, and specifically identified the following commodities: Dimension stone (SIC code 1411); Kaolin and Ball Clay (SIC code 1455); and Clay, Ceramic, and Refractory Minerals (SIC code 1459 - except bentonite) as eligible. The Division highlighted these specific commodities as Division records indicate that discharges from such facilities have been previously permitted -- such facilities are not prohibited from discharging by an applicable federal ELG, and the pollutants of concern are similar to other facilities eligible for coverage under the permit. 2. Process water discharges from Graphite mining facilities The Division clarified the types of discharges from graphite facilities that are eligible for coverage under the permit. In accordance with the Federal ELG for graphite facilities, "Only that volume of water resulting from precipitation that exceeds the maximum safe surge capacity of a process waste water impoundment may be COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 15, Permit No. COG500000 discharged from that impoundment. The height difference between the maximum safe surge capacity level and the normal operating level must be greater than the inches of rain representing the 10 -year, 24 -hour rainfall event as established by the National Climatic Center, National Oceanic and Atmospheric Administration for the locality in which such impoundment is located." 3. Discharges from facilities that produce Phosphate rock (SIC code 1475) excluded from coverage The Division removed from the types of facilities eligible for coverage under the permit, facilities that produce Phosphate rock (SIC code 1475). The Division determined that the pollutants of concern associated with Phosphate rock are different from other facilities eligible for coverage under the permit (based on the Toxic Pollutant Potential factor for the NPDES Permit Rating Work Sheet), and review of Division and DRMS records indicates that facilities that produce Phosphate rock are not currently permitted. Any new facilities that produce Phosphate rock and require discharge permit coverage must apply for an individual permit or an alternative general permit, as applicable. 4. Process water discharges from asphalt batch plants excluded from coverage The Division determined, based on review of the applicable federal ELG (40 CFR 443) and associated Development Document, that the required level of technology -based control (BPT/BAT/NSPS) for discharges from facilities that produce asphalt concrete is 'no discharge of process wastewater pollutants to navigable waters'. Therefore, the Division excluded process water discharges from asphalt batch plants from coverage under this permit. 5. Process water discharges from concrete batch plants (including truck wash water /drum wash out) excluded from coverage The Division determined that the pollutants of concern associated with truck wash water and process water discharges from concrete batch plants are different and potentially more toxic than those for other facilities eligible for coverage under the permit. Therefore, the Division excluded process water discharges from concrete batch plants from coverage this permit. 6. Flow limitation The Division added a flow limitation in the permit, as required by 5 CCR 1002-61.8(2)(i). The chronic flow limit will be equal to the maximum monthly average flow rate provided in the permit application. As required by 5 CCR 1002-62.5(7), the flow -measuring device must indicate values within ten percent of the actual flow being measured. The division is also requiring reporting for total quarterly flow in cases where needed to support a loading analysis. 7. Standardized monitoring frequency The final permit provides coverage for process water discharges from both `minor' and `major' facilities, determined using the NPDES Permit Rating Work Sheet. Therefore, the final permit contains monitoring frequencies for both major and minor facilities, consistent with Water Quality Control Division Policy WQP-20 (Baseline Monitoring Frequency, Sample Type, and Reduced Monitoring Frequency Policy for Domestic and Industrial Wastewater Treatment Facilities). 8. Separate monitoring parameter line for selenium The Division added a separate line for selenium in the effluent limitations tables in Part I.C.1 of the permit (selenium was included in the `Other Pollutants of Concern' line in the previous permit). This change was made for clarity, and to clearly identify the regulatory basis for selenium monitoring. C. Stormwater 1. Control measures The Division uses the term "control measure" instead of "Best Management Practice (BMP)" throughout this permit. This term has a broader range of meaning than BMP, as it includes both BMPs and "other methods", and COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 16, Permit No. COG500000 as such, better describes the range of pollutant reduction practices a permittee may implement. The Division does not typically mandate specific control measures a permittee must implement to control pollutant sources at their facility. The permittee has the flexibility to select appropriate control measure that when implemented, enable the permittee to meet all applicable permit effluent limitations for stormwater discharges from their facility. In this part of the permit, the Division uses and defines the term "minimize" to provide the permittee with a clear expectation for the level of performance of control measures implemented to achieve effluent limits that require the permittee to "minimize" pollutants. The Fact Sheet for EPA's MSGPs provides significant discussion about both terms with respect to the levels of technology -based control required by this permit. This permit requires that installation and implementation specifications be retained with the Stormwater Management Plan for each control measure used by the permittee to meet the effluent limitations contained in the permit. The Division finds that this necessary to ensure the permittee recognizes, selects, and implements control measures that are appropriate for specific pollutant sources. The Division's expectation for maintenance of control measures is that the permittee conduct this action "immediately, in most cases". The intent of this permit condition is that the permittee correct control measures as they are discovered, and that interim control measures are implemented while the primary control measure is corrected. 2. Stormwater Discharge Effluent Limitations This permit identifies all stormwater effluent limitations required by the permit (practice -based effluent limits and water quality -based effluent limitations), and clearly states that all discharges authorized under the permit shall attain these effluent limitations. This permit does not contain any numeric effluent limits based on effluent limitation guidelines (ELGs) for stormwater, as they are not applicable to the discharges eligible for coverage under this permit. The effluent limitations contained in this permit are located in a section separate from the SWMP, thereby differentiating effluent limitations from other terms and conditions of the permit. The practice -based effluent limits (PBELs) are technology -based effluent limits - technology -based effluent limits are required for all CDPS permits. The PBELs correspond to the required levels of technology -based control (BPT, BCT, BAT) for various discharges under the Colorado Water Quality Control Act. For this permit, the technology -based effluent limits for stormwater discharges (i.e., the PBELs) are based on Best Professional Judgment (BPJ) decision -making. The renewal permit includes water quality -based effluent limits as necessary to meet applicable water quality standards and supplement the technology -based effluent limits. The Division determined that it was appropriate to include the BPJ based technology -based effluent limits and the water quality -based effluent limits on the same basis EPA used in development of EPA's MSGPs. a. Practice -based Effluent Limitations The Division modified the practice -based effluent limitations required by this permit. Most significant among the changes are including the term "minimize" within the practice -based effluent limitations, and adding four new practice -based effluent limitations, as described below. i. Minimize Exposure Minimizing exposure prevents pollutants from coming into contact with precipitation and can reduce the need for control measures to treat or otherwise reduce pollutants in stormwater runoff. As such, this is one of the most important control options. ii. . Management of Runoff Managing runoff (diverting, infiltrating, reusing, containing, or treating stormwater runoff) prevents stormwater contact with exposed materials or pollutant sources, and like minimizing exposure, can reduce the need for control measures to treat or otherwise reduce pollutants in stormwater runoff. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 17, Permit No. COG500000 iii. Waste, Garbage and Floatable Debris In addition to other stormwater pollutants, the permittee must minimize the discharge of waste, garbage, and floatable debris, pollutants associated with most if not all industrial activities, so that these pollutants are not ultimately discharged to receiving waters. Trash and floating debris in waterways have become significant pollutants, especially near areas where a large volume of trash can be generated in a concentrated area. Trash can cause physical impairments in water bodies to aquatic species and birds, is also visual pollution, and detracts from the aesthetic qualities of receiving waters. iv. Salt Storage Piles or Piles Containing Salt Salt storage piles are prevalent across the country. The permit requires that permittees adequately control salt piles to prevent aquatic effects resulting from stormwater runoff from such piles. Preventing exposure of piles to stormwater or run-on also eliminates the economic loss from materials being dissolved and washed away. b. Water Quality -Based Effluent Limitations The renewal permit includes a new section that addresses water quality -based effluent limitations (WQBELs) applicable to stormwater discharges. The permit allows the Division to conduct a reasonable potential analysis that allows one of three outcomes to be determined: 1) a finding of reasonable potential, which for a new (proposed) discharge would need to be based on information other than monitoring from the proposed facility, such as monitoring information for similar sites/discharges, published scientific information, or information in the application, 2) a monitor -only reasonable potential decision, which indicates that the Division expects the pollutant to be present in the discharge, but does not have certainty that levels will cause or contribute to an exceedance of a water quality standard, or 3) a finding of no reasonable potential and no monitoring, indicating that the Division either does not expect the pollutant to be present or if expected to be present it is at levels significantly below the applicable water quality standard. i. Water Quality Standards a) Consistent with EPA's MSGPs and general permit COR900000, the Division included the requirement that `stormwater discharges authorized under the renewal permit must be controlled as necessary to meet applicable water quality standards'. Generally, this means attaining the water quality standards in the receiving water, but may be end -of -pipe due to site - specific circumstances such as for new discharges to impaired waters. This statement replaces the statement in the preceding sand and gravel stormwater permit that `stormwater discharges from the industrial activity shall not cause, have the reasonable potential to cause, or measurably contribute to an exceedance of any water quality standard, including narrative standards for water quality'. This requirement applies to all stormwater discharges; additional requirements apply to discharges to Water Quality Impaired Waters and Waters Designated as Critical Habitat for Threatened and Endangered Species, as described below. b) The Division expects that compliance with the other conditions in the renewal permit will control discharges as necessary to meet applicable water quality standards. However consistent with EPA's MSGPs and general permit COR900000, the Division included a provision in the permit that allows a site -specific water quality -based effluent limitation to be included in the certification as necessary to comply with water quality standards. The Division also included a provision in the permit that allows site -specific terms and conditions to be included in the certification to determine whether compliance with the other terms and conditions of the permit will control the discharge as necessary to meet applicable water quality standards. c) The type of information that the Division anticipates may become available substantiating the need for a site specific water quality -based effluent limitation includes, but is not limited to, in - stream water quality data, discharge monitoring data and information regarding corrective COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 18, Permit No. COG500000 actions. Any site -specific water quality -based effluent limitation will be derived from and comply with the associated water quality standard. d) The type of additional terms and conditions the Division anticipates could be appropriate to determine if compliance with the other terms and conditions of the permit will control the discharge as necessary to meet applicable water quality standards includes, but is not limited to in stream monitoring, site -specific discharge water quality standards monitoring, site -specific benchmarks, and source characterization studies. ii. Additional Requirements for Discharges to Water Quality Impaired Waters a) Existing Discharge to an Impaired Water with an EPA Approved or Established TMDL. Consistent with EPA's MSGPs and general permit COR900000, the Division will implement a new review process for existing discharges to impaired waters with an approved or established TMDL. Where an operator indicates on its application that the discharge is to one of these waters, the Division will determine whether the pollutant is of concern for the discharge and review the applicable TMDL to determine whether the TMDL includes requirements that apply to the individual discharger or to its industrial sector. The Division will determine whether additional requirements are necessary to comply with the wasteload allocation or alternatively, whether an individual permit application is necessary. Where the discharge is authorized under the general permit, the Division may include water quality standards monitoring to verify that the discharge will be controlled as necessary to be consistent with the assumptions and requirements of the TMDL through compliance with the other terms and conditions of the general permit. The Division utilizes this process for new discharges to impaired waters, and intends to extend this process to existing discharges to impaired waters in this category under this renewal permit. The Division included a specific section regarding water quality standards monitoring in the permit. Stormwater discharges to stream segments subject to the selenium TMDL — The EPA approved a selenium TMDL for the Gunnison River and Tributaries, Uncompahgre River and Tributaries, in February 2011. This TMDL identifies that selenium contributions to sand and gravel discharges occur when selenium -laden groundwater intercepts sand and gravel pits and is discharged as process water. Therefore, for the 12 segments subject to the TMDL identified above and for this permit term, the Division will not require permittees to sample stormwater-only discharges for selenium, for such discharges from the facility through outfalls not associated with the mining pit (e.g., through sheet flow, diverted stormwater, detained stormwater, etc.). b) Existing Discharge to Impaired Waters without an EPA Approved or Established TMDL. The Division will implement a new review process for existing discharges to impaired waters without an approved TMDL. Where an operator indicates on its application that the discharge is to an impaired waters where a TMDL has not yet been established, the Division will determine whether a pollutant has been identified as a constituent of concern in an impairment listing, and if this constituent it is a concern for the proposed discharge covered by the permit. If so, the Division may include water quality standards monitoring to provide information to support development of the TMDL and to determine if the discharge, once a TMDL is issued, will be controlled as necessary to be consistent with the assumptions and requirements of the TMDL through compliance with the other terms and conditions of this permit. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 19, Permit No. COG500000 The Division utilizes this process for new discharges to impaired waters, and intends to extend this process to existing discharges to impaired waters in this category under this renewal permit. The Division included a specific section regarding water quality standards monitoring in the permit. c) New Discharge to an Impaired Water. The Division considered emulating the conditions included in EPA's MSGPs and determined that an alternate approach was more appropriate for this permit and consistent with permitting practices conducted by the Division in Colorado. EPA's MSGPs substantively addresses requirements for new discharges to impaired waters under limitations on coverage and does not include additional water quality -based effluent limits to further control those discharges. In EPA's MSGPs, EPA included language from the permit regulations that prohibit issuance of a permit to new discharges to impaired waters in certain circumstances, as a permit condition under limitations on coverage. The Division has had a longstanding practice of meeting the subject regulatory prohibition through two practices: 1) assigning water quality -based effluent limits at the point of discharge (end of pipe) to new discharges to impaired waters, which does not allow a discharge to cause or contribute to a violation of a water quality standard, and 2) denying permit applications in cases where the Division has determined (and the applicant has been unable to substantiate otherwise) that the discharge without additional treatment or controls, would not be controlled as necessary to meet to meet permit terms and conditions, specifically water quality -based effluent limits. The Division intends to continue that process with this renewal permit, and has included a narrative water quality -based effluent limitation in the permit, which will be included in permit certifications authorizing new discharges to impaired waters, including naming the relevant water quality standards. The Division determined that it was appropriate to include a narrative water quality - based effluent limitation in the permit as an additional protection to ensure compliance with water quality standards and make it clear to the permittee that water quality standards must be met at the point of discharge (end of pipe). In addition, where an operator indicates on its application that the discharge is to an impaired water, the division will determine whether a pollutant (including selenium) is of concern for the discharge. If so, the Division may include water quality standards monitoring to provide information to support development of the TMDL and to determine if the discharge, once a TMDL is issued, will be controlled as necessary to be consistent with the assumptions and requirements of the TMDL through compliance with the other terms and conditions of this permit. iii. Additional Requirements for Discharges to Waters Designated as Critical Habitat for Threatened and Endangered Species. The Division, EPA, and USFWS entered into a Memorandum of Agreement (MOA) "regarding enhanced coordination in implementing Colorado's mixing zone rule and the Service's August 11, 2003 biological opinion on this matter" in October 2005 (The Mixing MOA). The Mixing MOA evolved from an Endangered Species Act (ESA) Section 7 consultation that was conducted as part of EPA's approval of Colorado's water quality standards mixing zone provisions. In development of the Mixing MOA, the parties were primarily focused on ensuring no more than minor detrimental effects from larger, continuous point source discharges during critical low flow conditions. Since execution of the Mixing MOA and consistent with options included in the Mixing MOA, the Division's has issued permits for larger, continuous discharges that have required the discharges to meet water quality standards at the point of discharge (end of pipe) based on critical low flow conditions. The Division has also required a large continuous discharge to occur from a diffuser to ensure instantaneous COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 20, Permit No. COG500000 mixing. The Mixing MOA also includes an option for passive mixing in situations where the permittee can demonstrate that such mixing will be protective of the listed species. The Division has determined that additional information is needed to determine whether compliance with the other conditions of this permit will control the discharges as necessary to eliminate or minimize the potential for no more than minor detrimental effects to listed species in regards to receiving water mixing. The Division has included a provision in the permit that requires water quality -based monitoring for discharges to waters designated as critical habitat for threatened and endangered species. The Division has also included a provision that allows additional terms and conditions to be included in the certification, and the types of additional terms and conditions the Division anticipates could be appropriate includes, but is not limited to studies to determine whether instantaneous mixing occurs due to the location of the discharge and flow in the receiving water at the time of discharge, and studies to determine whether passive mixing is protective of listed species. iv. Additional Requirements for New or Increased Discharges to Reviewable Waters Consistent with EPA's MSGPs and general permit COR900000, the Division expects that compliance with the other conditions of the permit will control discharges as necessary to comply with the applicable antidegradation requirements. However, the Division included a provision in the permit that allows additional terms and conditions to be included in the certification as necessary to comply with antidegradation requirements. Types of information that may become available warranting site -specific conditions includes but is not limited to information on new or increased discharges, including information provided consistent with Part I.I and Part II (Change in Discharge) of the renewal permit. 3. General Monitoring Requirements — Stormwater Only The Division consolidated and clarified stormwater monitoring requirements for the permittee in this section of the renewal permit. Applicable monitoring requirements in the renewal permit apply to each outfall authorized by the permit, except as otherwise exempt from monitoring as a "substantially identical outfall." Outfalls are locations where stormwater exits the facility property, including pipes, ditches, swales, sheet flow and other structures that transport stormwater (EPA 832-B-09-003 (Industrial Stormwater Monitoring and Sampling Guide — March 2009 [Final Draft]), or where the discharge enters a surface water within the facility permit boundary. To be considered substantially identical, outfalls must have generally similar industrial activities, control measures, and exposed materials that may significantly contribute pollutants to stormwater. When a permittee believes its facility has two or more outfalls that qualify as substantially identical, the permittee may monitor one of these outfalls and report that the quantitative data also apply to the other substantially identical outfalls. The Division encourages permittees to use the "substantially identical outfall' provision in the permit as it can significantly reduce the monitoring recordkeeping and reporting burden. In addition to the monitoring exception included the draft permit (i.e., Monitoring Exceptions for Inactive and Unstaffed Sites), the final permit contains an additional monitoring exception (Monitoring Exceptions for Completed and Finally Stabilized Areas) for mine sites, or areas of the mine site, where the pollutant potential and potential for control measure failure is significantly reduced. Please see the Division Response to Public Comments for a discussion of these changes. 4. Specific Monitoring Requirements — Stormwater Only The Division added a new section that addresses requirements for Visual Monitoring and Water Quality Standards monitoring requirements, as applicable to the facility. Consistent with EPA's MSGPs and COR900000, the Division added the requirement for the permittee to conduct quarterly visual examinations of stormwater discharges for the presence of obvious indicators of stormwater pollution. These assessments of stormwater discharges are an inexpensive and valuable part of the stormwater management and planning process. Permittee responsibilities with respect to documentation of results and corrective actions are provided. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 21, Permit No. COG500000 The final permit authorizes stormwater discharges from asphalt batch plants (SIC code 2951) and concrete batch plants (SIC code 3273). Therefore, the division also added the associated benchmark sampling requirements for these industrial activities, consistent with CDPS general permit COR900000, and described below. a. Stormwater benchmark sampling Sand and gravel industrial activities The renewal permit does not include benchmark sampling requirements for stormwater discharges from sand and gravel facilities (SIC code major group 14 activities). This is different from the Division's approach in the COR900000 general permit (Stormwater Discharges Associated with Non -Extractive Industrial Activity), which was to adopt the benchmark parameter and concentrations required in EPA's MSGPs — for sand and gravel facilities, EPA's benchmark parameters are Nitrate plus Nitrite Nitrogen and Total Suspended Solids (TSS). The Division deviated from the benchmark approach for this renewal permit for several reasons. First, because this permit addresses only one sector, and the sector requires monitoring and reporting for just two benchmarks, the Division had more time to evaluate the basis for the benchmarks, and weigh the pros and cons of adopting the benchmarks versus determining an equivalent alternative to the benchmark approach. Secondly, as provided in the 1995 Federal Register (Federal Register / Vol. 60, No. 189 / Friday, September 29, 1995), the benchmarks for this sector are Nitrate plus Nitrite Nitrogen and TSS, which are based on stormwater discharge monitoring data reported to EPA by the Sand and Gravel sector. The benchmark concentration for Nitrate plus Nitrite Nitrogen is 0.68 mg/I, and is based on data from the National Urban Runoff Program. The Division was concerned that since the source of the nitrogen is likely fertilizer used in reclamation efforts, that permittees could find themselves performing corrective action for exceeding the benchmark value for a pollutant that may not be controlled with conventional control measures for this sector. Further, the permit requires that permittees apply fertilizer in accordance with the approved labeling, and the narrative WQBEL is applicable to all discharges from Sand and Gravel facilities, including those that use fertilizer. Therefore, the Division determined that it would not apply Nitrate plus Nitrite Nitrogen benchmark sampling for discharges from these facilities in the renewal permit. The Division considered retaining the TSS benchmark sampling and reporting requirements and associated corrective action in the renewal permit; and looked at the cost and benefit of benchmark monitoring, and sampling and reporting for just one parameter, particularly one for which specific technology -based effluent limitations are addressed in the permit. The Division further considered that the Division of Reclamation, Mining and Safety provides some oversight of such facilities with respect to erosion and sediment control. In an effort to reduce the burden of sampling/reporting for one parameter, and because the Division determined that compliance with the technology -based effluent limitations (PBELs) and other terms and conditions of this permit (such as control measure requirements, visual monitoring, inspections, and documentation requirements) will adequately control stormwater discharges for TSS, the Division decided to not require TSS benchmark sampling for discharges from these facilities in the renewal permit. Asphalt batch plant and concrete batch plant industrial activities Because the final permit authorizes stormwater discharges from asphalt and concrete batch plants, the division included applicable benchmark monitoring requirements for these activities. • Benchmark Monitoring: This renewal permit contains the requirement to conduct benchmark monitoring as an indicator of the performance of the measures undertaken to meet the stormwater effluent limitations contained in the permit. This approach (including specific benchmark parameters and concentrations) is consistent with the benchmark monitoring requirement in the CDPS non -extractive industrial stormwater general permit (permit COR900000) for asphalt and concrete batch plants. The benchmark concentrations are not effluent limits. Therefore, an COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 22, Permit No. COG500000 exceedance of the benchmark four -quarter average is not a violation of the permit, provided that no separate water quality exceedance resulted from the associated stormwater discharges. • Benchmark Monitoring Schedule: The renewal permit requires that the permittee conduct benchmark monitoring quarterly for the first four (4) full quarters of permit coverage. • Benchmark Monitoring Actions: Data not exceeding benchmarks: Benchmark monitoring frequency can be reduced if the permittee can demonstrate monitoring values below the benchmarks concentrations. If, after collecting 4 benchmark samples, the average of the monitoring values for any parameter does not exceed the benchmark, the permittee may submit a request to the division to reduce benchmark monitoring frequency to once -per -year, and rotate through the quarterly monitoring periods such that eight (8) samples are collected every five years. This monitoring framework allows samples to capture seasonal variations in stormwater discharges, yet relieves the permittee from quarterly sampling for the entire permit term, unless the benchmarks are exceeded (see below). • Data exceeding benchmarks: The renewal permit specifies Corrective Actions (required permittee actions, documentation and timelines) when the averaged monitoring values for any parameter exceeds the benchmark. After corrective action is taken, the permittee is required to continue quarterly monitoring for 4 additional quarters, and calculate average monitoring values. If the data from the additional monitoring does not exceed the benchmarks, permittees may reduce benchmark monitoring frequency to once -per -year as previously described. If this data from the additional monitoring exceeds the benchmarks, the permittees must again perform Corrective Actions and continue quarterly sampling. This monitoring framework requires continued quarterly sampling only for those facilities that continue to exceed benchmarks in stormwater samples. 5. Inspections The Division modified the self -inspection requirements in the renewal permit. Most significant among the changes are inspection frequency (i.e., quarterly inspections); inspection scope (i.e., one inspection must be conducted during a run-off event); and corrective action requirements. This permit specifically addresses an increased inspection frequency (6 per year) for inactive and unstaffed facilities that do not meet the condition of no exposure, as such facilities continue to be sources of pollutants for stormwater runoff. The Division made changes to this section of the permit largely based on its observations during compliance inspections of permitted sand and gravel facilities. Such observations include non -compliant field conditions the permittee did not identify and correct. Unlike the public notice version of general permit COR900000, this permit requires quarterly not monthly inspections, although in some instances, more frequent inspection (e.g., monthly) may be appropriate for areas of the facility with significant activities and materials exposed to stormwater. The Division believes that the requirement for more frequent facility inspections (i.e., quarterly inspections) and documented corrective actions is a useful means for permittees to evaluate the effectiveness of implemented control measures, and correct any deficiencies. The Division also added the requirement to conduct one of the quarterly inspections during a run-off event, consistent with general permit COR900000. The Division determined that the run-off event inspection is a particularly useful tool for assessing control measure performance, and has received anecdotal information from permittees/stakeholders authorized under general permit COR900000 substantiating this determination. As in general permit COR900000, this permit allows an exception to the quarterly inspection frequency for inactive and unstaffed facilities, but only if a condition of no exposure is first established at the facility and documented in the facility SWMP. If this is the case, such facilities are required to conduct two facility inspections annually, in the spring and fall. This twice yearly inspection frequency is intended to ensure that COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 23, Permit No. COG500000 there are no industrial materials or activities exposed to stormwater, i.e., to maintain the condition of no exposure. Facilities that are both inactive and unstaffed, when the facility no longer has industrial activities or materials exposed to stormwater, could alternatively submit a No Exposure Certification permitting under 5 CCR 1002-61.3(2)(h), terminating permit coverage. However, the Division realizes that some facilities plan to recommence industrial activity in the future and therefore may wish to keep active permit coverage. The permit also includes an increased frequency requirement (6 per year) for those facilities that are inactive and unstaffed, but that cannot establish a condition of no exposure. The Division recognizes that some facilities, such as those meeting the conditions of "temporary cessation" in accordance with DRMS requirements, continue to be sources of pollutants as these facilities are not reclaimed, and may not be able to qualify for a condition of no exposure. Because the discharge of pollutants does not cease when pollutants sources at such facilities remain exposed to stormwater, oversight of facility conditions by the permittee is necessary. The increased inspection frequency provides an alternative approach to requiring that permittees conduct quarterly visual monitoring for such facilities, as in general permit COR900000. The Division recognizes the burden associated with obtaining visual samples of stormwater at remote facilities that are not staffed, and developed the increased inspection frequency option accordingly. This is the Division's best effort to balance having requirements adequate to address the pollutant source, while reducing the burden to the extent possible since the facilities are not staffed to support active mining operations. In response to comments received during the public notice period, the division added an additional exception to the inspection requirements in the final permit, specifically for the runoff event inspection at Completed and Finally Stabilized Areas (see response to Comment ID COG50-5.11). 6. Corrective Actions This new section identifies permittee responsibilities with respect to resolving specific facility conditions. The corrective action process is critical to fixing conditions occurring during the permit term that are indicative of permit violations. Conditions fall into two categories: those the permittee must eliminate, and those that require the permittee to review and modify control measures. Permittee responsibilities with respect to corrective action reports and deadlines, control measure modification and substantially identical outfalls are addressed. In the final permit, the 24 -hour and 5 -day reporting requirements are condensed into one 5 -day reporting requirement. 7. SWMP requirements This permit locates all technology -based effluent limitations (i.e., practice -based effluent limitations and federal ELGs), and water -quality based effluent limitations in sections separate from the requirement to develop and implement a SWMP. As such, the requirement to prepare a SWMP and the documentation requirements set forth in the SWMP are not effluent limitations themselves, but terms and conditions of the permit, because the permittee is documenting information on how it intends to comply with the effluent limitations of the permit. This difference allows the permittee to modify, at any time and as required by the terms and conditions of the permit, the control measures used to meet these effluent limitations. The Fact Sheets for EPA's MSGPs provides significant discussion regarding the effluent limitation vs. the requirement to develop a SWMP, as required by this permit. The final permit allows 180 days from the certification effective date, for an existing permittee to modify the SWMP to meet the final permit requirement. Please see the Division Response to Public Comments for a discussion of this change. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 24, Permit No. COG500000 a. General SWMP Requirements i. SWMP requirement: The Division added the requirement that the permittee must modify the SWMP to reflect current site conditions. The Division expects that the permittee use the SWMP as a tool to plan and implement stormwater management at the facility. The requirement that permittees update the facility SWMPs to reflect current site condition formalizes this expectation. ii. Signatory Requirements: The Division added the requirement that the permittee must sign and certify all SWMPs, which applies to the original SWMP prepared for the facility, and each time the permittee modifies a SWMP. This requirement ensures that the individual or a position with responsibility for the overall operation of the regulated facility or activity, or a duly authorized representative of that person consistent with 5 CCR 1002-61.4(1)(f), is aware of and approves changes to the SWMP. iii. Permit Retention: The Division added the requirement that the permittee must maintain a copy of this renewal permit and the permit certification issued to the permittee with the SWMP. The Division determined that it is appropriate to require the permittee to retain a copy of this permit and the permit certification with the SWMP to allow the facility's personnel ready access to both. The Division notes that an electronic copy easily available to facility personnel is also acceptable. b. Specific SWMP Requirements The Division modified the Specific SWMP Requirements to require that permittees maintain additional documentation with the SWMP. These documentation requirements include: i. Facility Map. The Division added a requirement to the renewal permit that requires permittees to identify the locations and sources of run-on to the facility from adjacent property that contains significant quantities of pollutants. ii. Facility Inventory and Assessment of Pollutant Sources. The Division added the requirement to maintain, and update as data is available, an assessment of potential pollutant sources that describes the potential of a pollutant to be present in stormwater discharges for each facility activity, equipment and material identified by the permittee. iii. Additional Control Measure Requirements. The Division added the requirement to document, and maintain with the SWMP, the schedules, procedures, and evaluation results for the following subset of practice -based effluent limitations. • Good Housekeeping; • Maintenance; • Spill Prevention and Response Procedures; • Employee Training; and, • Non-Stormwater Discharges. The stormwater provisions in existing permits COR340000 and COG500000 require such procedures and practices — this permit additionally requires that the permittee document these procedures and practices in the SWMP. Documentation may be electronic as long as all other requirements of the permit are met. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 25, Permit No. COG500000 iv. Inspection Procedures and Documentation. The Division added the requirement to document, and maintain with the SWMP, inspection procedures and other documentation related to inspections. v. Monitoring Procedures and Documentation. The Division added the requirement to document, and maintain with the SWMP, monitoring procedures and other documentation related to monitoring. 8. Reporting and Record keeping Permittees required to sample stormwater, other than visual monitoring, must summarize monitoring results for each calendar quarter and submit the results to the division on a quarterly basis (by the 28th day of the following month). These changes are consistent with the existing reporting convention for monitoring results in Division permits. The Division enters all industrial stormwater facility data into EPA's database of record, which is called the "Integrated Compliance Information System" (ICIS), and is a secure system for National Pollutant Discharge Elimination System (NPDES) that is only available to EPA and state users. The public can access information in ICIS by using the "Enforcement and Compliance History Online" (ECHO), or Envirofacts. The final permit includes requirements regarding EPA's Net-DMR submittal, and dates when permittees must start reporting data electronically. Prior to December 21, 2016, the permittee may elect to electronically submit DMRs instead of mailing paper DMRs by using the EPA's Net-DMR service. Starting on December 21, 2016, the permittee must electronically report DMRs by using the EPA's Net-DMR service unless a waiver is granted in compliance with 40 CFR 127. To ensure that permittees know how to report information on the DMR form, this permit contains data reporting conventions, to include reporting "No Discharge" on the DMR if no discharge occurs within the reporting period; "General Permit Exemption" for each parameter for the period the site meets the monitoring exception. The Division modified the required content of the Annual Report. Specifically, only a summary of inspection dates need to be reported; however, all correct action documentation (including that for inspections) and the status of any outstanding corrective action(s) must be submitted with the annual report. As such, the annual reporting requirements are less than that required by the previous permits, unless the facility has corrective actions to document. VI. DISCUSSION OF PROCESS WATER EFFLUENT LIMITATIONS A. Regulatory Basis for Limitations 1. Technology Based Limitations a. Federal Effluent Limitation Guidelines — The federal guidelines that apply to discharges from sand and gravel facilities are found under 40 CFR Part 436 (Mineral Mining And Processing Point Source Category). These limitations will typically apply, unless the Division applies a more stringent limitation or an alternate limitation (as is the case with pH, as discussed in the Parameter Evaluation section of the fact sheet). b. Regulation 62: Regulations for Effluent Limitations — Regulation 62 includes effluent limitations that apply to all discharges of wastewater to State waters. This regulation is applicable to the discharges from sand and gravel facilities certified under the COG500000 permit, and is the basis for the oil and grease and total suspended solids (TSS) effluent limitations where federal Effluent Limitation Guidelines do not apply to the discharge. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 26, Permit No. COG500000 2. Numeric Water Quality Standards For sand and gravel facilities, applicable water quality standards exist for pH, metals, and organic parameters, and may be applied as daily maximum (acute), 30 -day average (chronic) limits, or two-year rolling averages. Most acute and chronic water quality standards will apply at the point of discharge (end -of -pipe), with case -by - case exceptions for select parameters, which are detailed below. While effluent limitations for metals and other parameters are not automatically included in certifications under this general permit, they may be added on a case -by -case basis based on discharge- or receiving water -specific considerations. 3. Narrative Water Quality Standards Section 31.11(1)(a)(iv) of The Basic Standards and Methodologies for Surface Waters (Regulation No. 31) includes the narrative standard that State surface waters shall be free of substances that are harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life. a. Agricultural Use Protection (SAR, EC, and TDS) - Section 31.13(2) of the Basic Standards and Methodologies for Surface Waters (Regulation No. 31) also includes specific narrative provisions for the protection of agriculture as follows; Agriculture. These surface waters are suitable or intended to become suitable for irrigation of crops usually grown in Colorado and which are not hazardous as drinking water for livestock. For the protection of irrigated crops, the Division initiated a workgroup in 2007 to address concerns about the impacts of industrial discharges on the quality of downstream water and its suitability for use in irrigating crops. As a result of the workgroup, the Division determined that additional discharge controls were necessary in certain situations to protect the beneficial uses of downstream crop irrigation. This culminated in Water Quality Policy (WQP) #24, entitled Implementing Narrative Standards in Discharge Permits for the Protection of Irrigated Crops (hereafter the Ag Policy), March 10, 2008. The evaluation of the suitability (i.e., quality) of irrigation water is complex and involves interactions of plant tolerances, soil types, and agricultural management practices. Irrigation water has two properties — salinity and sodicity — that can have concurrent impacts on the irrigated crop beneficial use. The Division has thus determined that two parameters, specifically electrical conductivity (EC) and sodium absorption ratio (SAR), are the best parameters to regulate in discharge permits to control levels of salts to minimize both the loss of irrigated crop yield and the sodium hazard. Electrical Conductivity (EC or Specific Conductivity): Crops have varying sensitivity to electrical conductivity. Studies have established the maximum conductivity in the water that will result in a `no reduction' of crop yield. Thus, an EC value based on a `no reduction' of crop yield is implemented in permits as the maximum conductivity based on the most sensitive crop usually grown in the area. Common crop EC thresholds reproduced from the Ag Policy are summarized in the table below. Note that this is not an exhaustive list and ECvalues for additional crops are listed in tables in appendixes to the Ag Policy. Maximum EC,„, That Will Not Reduce The 100% Yield of Selected Irrigated Crops Common Colorado Crops Irrigation Water Electrical Conductivity (ECW) Beans 0.7 Onion 0.8 COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 27, Permit No. COG500000 Maximum ECW That Will Not Reduce The 100% Yield of Selected Irrigated Crops Common Colorado Crops Irrigation Water Electrical Conductivity (ECW) Corn (grain) 1.1 Potato 1.1 Peaches 1.7 Corn (silage) 1.2 Alfalfa 1.3 Orchard grass 1.5 Grapes 1.5 Wheat 4.0 Sugarbeet 4.7 Barley 5.3 The permit writer will determine if EC must be limited and/or monitored in the discharge to protect downstream crop irrigation. For new discharges, this may include an EC limitation in the permit, if warranted. For existing discharges, a 'report' only requirement is anticipated during this permit term to characterize EC in discharges from this industry. Sodium Adsorption Ratio (SAR): This value is a representation of the relative proportion of sodium cations to calcium and magnesium cations (also known as the "sodium hazard"). The equation for SAR follows: SAR Na + C.. a ++ + Mg' 2 The SAR standard used to establish a SAR permit limit, is calculated using the SAR/EC equation of SAR = (7.1* EC) -2.48), reproduced herein from the Ag Policy. A permit limitation for SAR is based on this calculation using an EC value from the established crop grown in the area. For example, CORN GRAIN IRRIGATED CROP EC for Corn (grain) = 1.1 SAR= (7.1 *1.1)-2.48=5.3 Note that to retain a `no reduction in infiltration' per the Ag policy, SAR permit limitations are capped at 9. Please see the Ag policy for a full discussion of EC and SAR for irrigated crops. Since sand and gravel process water discharges covered under this permit are typically from shallow mining operations (e.g. alluvial pit dewatering), or from processing related to materials extracted from shallow deposits (crushing, sorting, screening, etc.), SAR values in the soil profile can be used to estimate the concentrations of SAR in the effluent. The Division reviewed statewide NRCS SSURGO Soils profiles in areas where the majority of process water discharges occur. The result of this analysis indicates that, for the vast majority of sites, there is no reasonable potential for SAR to cause or contribute to an exceedance of the standard. Thus, monitoring for SAR will not typically be required. Note however, that for facilities located in high SAR soil locations, or facilities where SAR is expected in concentrations that may cause or contribute to an exceedance of the standard, a limitation or reporting for SAR may be implemented on a case -by -case basis. An individual permit may be requested for detailed mixing zone (dilution) considerations, if warranted. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 28, Permit No. COG500000 Total Dissolved Solids (TDS) - The Division's practice has been to include a TDS limitation of 3,500 mg/I where discharges are to surface waters that are used for livestock (range cattle) watering. This practice is based on EPA's "Blue Book" (Water Quality Criteria 1972 ("Blue Book"). U.S. Environmental Protection Agency. Wash., D.C.: U.S. Government Printing Office, #R3-73-003, 3/73. The "Blue Book" was developed by a Committee on Water Quality Criteria formed through the National Academy of Sciences. The Colorado State University (CSU) Cooperative Extension also uses the "Blue Book" values as recommendations for livestock watering (Livestock Drinking Water Quality, CSU Cooperative Extension, October 1993, Reviewed March 1999). b. Whole Effluent Toxicity - The Division has established the use of Whole Effluent Toxicity (WET) testing as a method for identifying and controlling toxic discharges from wastewater treatment facilities. WET testing is used as a means to ensure that there are no discharges of pollutants "in amounts, concentrations or combinations which are harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life" as required by Regulation 31, Section 31.11 (1). The requirements for WET testing are implemented in accordance with Division policy, Implementation of the Narrative Standard for Toxicity in Discharge Permits Using Whole Effluent Toxicity (Sept 30, 2010). 4. Water Quality Regulations, Policies, and Guidance Documents a. Antidegradation — As required by Section 31.8 of The Basic Standards and Methodologies for Surface Water, an antidegradation (AD) review is required for discharges to "reviewable waters", except in cases where the regulated activity will result in only temporary or short term changes in water quality, or where the ratio of the low flow to the facility flow is 100:1 or more. Discharges permitted under this general permit are not normally temporary or short-term, thus, these discharges are not exempted from an AD review. Based on the information and data in the application, the permit writer will assess the ratio of the chronic low flow of the receiving stream to the facility design flow to determine if antidegradation applies. The AD review is applicable only to water -quality based effluent limitations, not technology -based effluent limitations. For discharges eligible under this general permit, an antidegradation (AD) limit will be calculated as 15% of the Water Quality Standard, and the resulting effluent limitation will be identified as a site -specific limitation in the certification. The permittee would then have the choice of this AD limit, or of a non -impact limitation (NIL). The NIL is either the limitation contained as of September 2000, or may be determined by the use of an implicit limitation if a previous limit did not exist. The implicit limit is determined as the maximum effluent concentration in the years prior to September 2000 (later data may be substituted on a case -by -case basis if data is unavailable from this time period). Alternately, if effluent data are not available, the division will include monitoring requirements in the permit so that data can be collected in order to make such a determination of an implicit limit. An individual permit will be required where the permittee requests consideration of dilution and ambient water quality. In addition, the permittee may elect to perform an alternatives analysis. As this may be subject to public notice requirements, an individual permit will be required. See Regulation 31.8(3)(d) and the Division's Antidegradation Guidance document for more information regarding an alternatives analysis. AD limitations will not be calculated for facilities discharging to segments that are impaired for a pollutant of concern. For these facilities, the water quality standard will be applied, as there is no new or increased impact to the assimilative capacity of the previously impaired stream segment. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 29, Permit No. COG500000 b. Discharges to Threatened and Endangered (T&E', Species Designated Waters — Discharges to T&E waters are subject to the Memorandum of Agreement between the Division and the U.S. Fish and Wildlife Service. In summary, a discharge to a T&E water must achieve one of three options: 1) The permit contains end of pipe limitations based on the water quality standards; 2) the permittee installs a diffuser, and is then granted a portion of the assimilative capacity of the receiving stream; or 3) the discharge is relocated to a segment that is not designated as T&E habitat. For facilities discharging to T&E species designated water, all WQBELs must be met at the point of discharge (end -of -pipe) and therefore, the first option is met. End -of -pipe limitations will satisfy the MOA, and no further consideration is needed. c. Antibacksliding — As the receiving waters are either designated Use -Protected, or the Division has performed an antidegradation evaluation in accordance with the Antidegradation Guidance, the antibacksliding requirements in Regulation 61.10 have been met. d. Implementation of Total Maximum Daily Loads (TMDLs) — When reissuing the renewal certifications and for new permit applications under this revised general permit, the Division will assess whether or not any permitted facility discharges to segments for which a TMDL has been completed and approved. As required under the Clean Water Act Section 303(d), TMDLs are submitted, through the normal public n otification process, to EPA Region VIII for their review and approval. At the present time, at least twelve sand and gravel facilities in the Gunnison and Uncompahgre Basins with effective permit certifications are subject to a waste load allocation (WLA) in the February 2011 selenium TMDL for the Gunnison River and Tributaries, Uncompahgre River and Tributaries. The Division will establish effluent limitations, consistent with the requirements and assumptions of the TMDL, and as consistent with the Reasonable Potential Analysis described in Part VI.A.4.i, below. Selenium limitations will be applied as necessary in the permit certifications issued to facilities assigned WLAs in the TMDL. As part of the renewal, the Division included a provision in the general permit that authorizes including additional effluent limits and other terms and conditions in a certification for discharges to segments for which a TMDL has been completed. The Division will apply a limitation in the certifications consistent with the assumptions and requirements of the TMDL. e. Determination of Discharges to 303(d) Listed Waters When reissuing the renewal certifications and for n ew permit applications under this revised general permit, the Division will assess whether or not any permitted facility discharges to segments, or may effect a downstream portion of a segment, on the 303(d) list of impaired waters. The Division has included a provision in the general permit that authorizes the inclusion of additional effluent limits and other terms and conditions in a certification for discharges to segments that are on the 303(d) list of impaired waters. The determination of whether compliance with numeric effluent limitations is required will be made on a case -by -case basis. f. Colorado Mixing Zone Regulations — With the exception of facilities discharging to segments assigned TMDLs, the mixing zone regulations do not apply to discharges covered under this general permit, as n early all effluent limitations are applicable at the point of discharge (end of pipe). The Division is not considering mixing zones for this general permit due to the time and resources required to conduct a thorough analysis of the receiving stream and associated assimilative capacity. g. Total Phosphorus — If the discharge from a facility, certified under this permit, ultimately impacts a water body subject to a Phosphorus Control Regulation, such as WQCC Regulations 71— 74, restrictions on the amount of total phosphorus discharged may be placed in the certification under this general permit. These control regulations may impose total phosphorus concentration limitations. No COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 30, Permit No. COG500000 phosphorus data have been submitted from these facilities in the previous permit term. Reporting requirements and/or limitations will be implemented for facilities discharging to the basins specified by these regulations. h. Salinity Regulations — In compliance with the Colorado River Salinity Standards and the Colorado Discharge Permit System Regulations (Regulation 39), the permittee shall monitor for total dissolved solids on a quarterly basis when discharging to the Colorado River basin. Data submitted during the previous permit term did not include loading calculations, and also displayed a large range of concentrations both between sites and within sites over time, rendering it difficult to determine compliance with the salinity standards. Therefore, reporting for both concentration and load (lbs/day) will be required in the permit certification. i. Reasonable Potential Analysis — Regulation 61, Section 61.8(2)(b)(i)(A) requires that permit limitations be placed upon any discharged pollutant that causes or contributes to, or that has the reasonable potential (RP) to cause or contribute to, an exceedance of water quality standards. The Division's RP analysis is based on the Division's procedural guidance Determination of the Requirement to Include Water Quality Standards -Based Limits in CDPS Permits Based on Reasonable Potential, dated December 2013. This guidance document utilizes both quantitative and qualitative approaches to establish RP depending on the amount of available data. A qualitative determination of RP may be made where ancillary and/or additional treatment technologies are employed to reduce the concentrations of certain pollutants. Because it may be anticipated that the limits for a parameter could not be met without treatment, and the treatment is not coincidental to the movement of water through the facility, limits may be included to assure that treatment is maintained. This is the case for pH, selenium and other metals, and organic compounds in discharges from sand and gravel facilities. A qualitative RP determination may also be made where a state or federal ELG exists for a parameter. This is the case for iron and fluoride (40 CFR Part 436 -Mineral Mining And Processing Point Source Category). To conduct a quantitative RP analysis, a minimum of 10 effluent data points from the previous 5 years, should be used. The equations set out in the guidance for normal and lognormal distribution, where applicable, are used to calculate the maximum estimated pollutant concentration (MEPC). For data sets with non -detect values, and where at least 30% of the data set was greater than the detection level, MDLWIN software is used consistent with Division guidance to generate the mean and standard deviation, which are then used to establish the multipliers used to calculate the MEPC. If the MDLWIN program cannot be used the Division's guidance prescribes the use of best professional judgment. For some parameters, recent effluent data or an appropriate number of data points may not be available, or collected data may be in the wrong form (dissolved vs total) and therefore may not be available for use in conducting an RP analysis. Thus, consistent with Division procedures, monitoring will be required to collect samples to support a RP analysis and subsequent decisions for a numeric limit. A compliance schedule may be added to the permit to require the request of an RP analysis once the appropriate data have been collected. For other parameters, effluent data may be available to conduct a quantitative analysis, and therefore an RP analysis will be conducted to determine if there is RP for the effluent discharge to cause or contribute to exceedances of ambient water quality standards. The guidance specifies that if the MEPC exceeds the maximum allowable pollutant concentration (MAPC), limits must be established and where the MEPC is greater than half the MAPC (but less than the MAPC), monitoring must be established. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 31, Permit No. COG500000 Where there is no RP, no concentration based effluent limit is included. However, the division has prescribed ongoing monitoring to inform future RP analyses and TMDL implementation. j. Intake Credits — The Division included a discussion of intake credits in this fact sheet in response to questions and written input received during the pre -public notice stakeholder process. In response comments received on the draft permit, the Division took a second look at the potential applicability of intake credits under the general permit. In doing so, the Division re -reviewed all available EPA guidance, including the EPA Region 8 memo on Intake Credits and the Region 5 Great Lakes System (GLS) rule which both discuss the application of intake credits. In general terms, an intake credit refers to the extent that the presence of a pollutant in intake waters should be considered when conducting a reasonable potential analysis and in the establishment of effluent limitations. Allowances for intake credits under the Clean Water Act were originally designed to apply in the context of cooling water intake structures or similar water uses where water from a surface water diversion was not chemically modified before it was discharged to the same stream. Intake credits may be available for other industrial processes, but are only allowed under very specific circumstances. Regulation 61 prohibits the Division from issuing intake credits if issuance would be inconsistent with federal law (Regulation 61.8(2)(d)(i)). As a preliminary matter, the Division concludes that intake credits incorporated into the general permit on an industry -wide basis are not appropriate under state or federal law. This position is consistent with numerous court decisions that have held that the application of intake credits can only be analyzed in the context of a particular factual setting. See American Iron & Steel Inst. v. EPA,115 F.3d 979, 999 (D.C. Cir.1997), citing NRDC v. EPA, 859 F.2d 156, 204-205 (D.C. Cir. 1988); Diamond Shamrock Corp. v. Costle, 580 F.2d 670, 674 (D.C. Cir. 1978). Intake credit availability differs based on the effluent limitation in the permit. Intake credit rules vary for technology -based effluent limits ("TBELs"), water quality based effluent limits ("WQBELs"), and WLAs assigned under a TMDL. The draft sand and gravel general permit contains TBELs, WQBELs, and WLA requirements. Any intake credits incorporated into the draft general permit must be consistent with EPA's requirements for TBELs, WQBELs, and WLAs. Intake Credits for a TBEL - EPA allows intake credits for TBELS if a discharger demonstrates that the intake water is drawn from the same body of water into which the discharge of effluent is made. 40 CFR §122.45(g)(4). The application of intake credits for TBELs is not at issue for this permit. Intake Credits for a WQBEL - National federal guidelines for intake credits for WQBELs have not been codified. EPA takes different approaches for WQBEL intake credits at a regional level. For many years, the Division relied upon a 1992 EPA Region 8 memo for guidance. EPA also adopted more official intake credit guidance for WQBEL in the Water Quality Guidance for the Great Lakes System (EPA Region V). 60 F.R. 15366. The Great Lakes System approach is not a legal requirement in Colorado since it only applies to EPA Region 7 states. However, the Division reviewed this approach as useful guidance to aid in its determination of whether intake credits could be applied. The Region VIII and Region V approaches are consistent, but the Great Lakes System rule is' much more comprehensive. Under the 1992 EPA Region 8 memo approach, intake credits are only available if: 1) the industrial activity discharging water in no way modifies the intake water character; 2) the point of diversion is the same waterbody as the point of discharge; and 3) the time of the discharge does not create a water quality standard exceedance that would not occur otherwise. Under the Great Lakes System approach, EPA developed procedures for considering intake pollutants in determining reasonable potential and for establishing WQBELs. EPA has allowed Great Lakes States to COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 32, Permit No. COG500000 determine that there is no reasonable potential for the discharge of an identified intake pollutant or pollutant parameter to cause or contribute to an excursion above a narrative or numeric water quality standard where a discharger specific demonstration is made in accordance with Procedure 5 of 40 C.F.R. §132 Appendix F. This demonstration must be made as part of a permit application, and must show that all five of the following conditions are satisfied: 1) The facility withdraws 100 percent of the intake water containing the pollutant from the same body of water into which the discharge is made 2) The facility does not contribute any additional mass of the identified intake pollutant to its wastewater 3) The facility does not alter the identified intake pollutant chemically or physically in a way that would cause adverse impacts to occur that would not occur if the pollutants were left in the stream; 4) The facility does not increase the identified intake pollutant concentration 5) The timing and location of the discharge would not cause adverse water quality impacts to occur that would otherwise not occur if the identified intake pollutant were left in the stream. 40 C.F.R. §132 Appendix F Procedure 5.D.3. 1) Same Body of Water requirement: In order to be considered the same body of water under Procedure 5, the permitting authority must determine that a pollutant in the intake water would have reached the vicinity of the outfall point in the receiving water within a reasonable period had it not been removed by the permittee. This can be demonstrated by showing that 1) the background concentration of the pollutant in the receiving water and the intake and the receiving water are the same; 2) there is a direct hydrologic connection between the intake and discharge points; 3) and the water quality characteristics are similar in the intake and receiving waters. An intake pollutant from groundwater may be considered to be from the same body of water if the permitting authority determines that the pollutant would have reached the vicinity of the outfall point in the receiving water within a reasonable period had it not been removed by the permittee. Importantly, a pollutant is not from the same body of water if the groundwater contains the pollutant partially or entirely due to human activity, such as industrial, commercial, or municipal operations, disposed actions, or treatment processes (40 C.F.R. §132, Appendix F, Procedure 5 D.2). The Division concluded that there has not been a sufficient demonstration that all sand and gravel facilities covered under the permit can sufficiently demonstrate the "same body of water" requirements under the Great Lakes System approach. Some commenters have argued that alluvial groundwater flowing into sand and gravel should generally be considered the same "body of water" as a surface water stream, based in part on assumptions of Colorado water rights administration and Water Quality Control Commission standards for alluvial wells. While these arguments have been made in general terms, they do not include site -specific analyses about intake and receiving water quality, hydrologic connection, and discharge characteristics for each covered facility. It is problematic to make general conclusions about the characteristics of the intake and discharge locations of all sand and gravel operations in the State of Colorado in the context of a general permit. Each individual mining operation has unique hydrology, and water that collects in a gravel pit may come from various sources. Making this conclusion on a state-wide basis is also inconsistent with previous decisions in the federal case law cited above. 2) Contribution of Additional Mass of Identified Pollutants: Under the Great Lakes System approach, EPA also allows states to consider intake pollutants in establishing effluent limits where reasonable potential exists. A permitting authority can establish limits based on a principle of "no net addition" (i.e., the limit would allow the mass and concentration of the pollutant to discharge up to the mass and concentration of the pollutant in the intake water. The COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 33, Permit No. COG500000 permitting authority may establish effluent limitations allowing the facility to discharge a mass and concentration of the pollutant that are no greater than the mass and concentration of the pollutant identified in the facility's intake water ("no net addition limitations"). This procedure allows the discharge to design and operate its treatment system to only remove the mass and concentration of the pollutant contributed by their operations. This determination can only be made if a permittee can also demonstrate that the intake water is from the "same body of water" as the receiving water. As stated previously, Division concluded that there has not been a sufficient demonstration that all sand and gravel facilities covered under the permit can sufficiently demonstrate the "same body of water" requirements; therefore the Division cannot issue an intake credit based solely on an analysis of the contribution of pollutant mass. However, looking at this issue independently, the Division also cannot concluded that, that "no reasonable potential" exists if intake credits were granted on an industry -wide basis to all covered facilities. There is not sufficient information about the individual intake and receiving water quality, and the water quality characteristic of the effluent being discharged from covered facilities to conclude that no reasonable potential exists. Furthermore, there is not sufficient information to determine the mass and concentration of intake water bodies and receiving water bodies. Without this information, the Division cannot conclude that all sand and gravel facilities throughout the state do not contribute additional mass of pollutants, are not increasing intake pollutant concentrations, do not alter the intake pollutant in a way that would cause adverse impacts, and are not timing their discharge in a way that would cause adverse water quality impacts. Intake Credits when a TMDL has been established — As a general rule, intake credits are generally not available for waterbodies where a TMDL has been established. The development of a TMDL process is the preferred mechanism for addressing the equitable division of the loading capacities in non - attainment waters (see 60 FR 15371). Discharge limitations in a WLA apply regardless of background water quality. Any application of intake credits to WLAs would need to occur through the TMDL process rather than a permitting process. Here, a TMDL has already been established on the Gunnison River and Tributaries, Uncompahgre River and Tributaries. The concept of intake credits was raised during the TMDL development process. Intake credits were not applied in the development of selenium TMDLs being implemented in this permit. Intake credits cannot be independently established along these stretches as part of the permitting process. The TMDL specifically identifies sand and gravel operators as a point -source contributor of selenium. (TMDL, p. 57-58). Water treatment at sand and gravel facilities typically consists of retention in settling ponds, and little, if any selenium removal is accomplished. (TMDL, p. 58). B. Parameter Evaluation 1. Total Suspended Solids (TSS) — Limitations for TSS in the renewal permit are based on both the federal ELG (as applicable to discharges from specific mining commodities) and Regulation 62. • Industrial Sand and Graphite Mining: The federal ELG (40 CFR Part 436) is applied to discharges consistent with Regulation 62. • The Regulation 62 TSS limitations are applied to all other process water discharges authorized by the permit, for which a federal ELG for TSS does not exist. These limitations are the same as those contained in the previous permit and are imposed upon the effective date of this permit. 2. Oil and Grease — Limitations for Oil and Grease in the renewal permit are based on Regulation 62. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 34, Permit No. COG500000 This limitation is the same as that contained in the previous permit and is imposed upon the effective date of this permit. 3. pH — This parameter is limited by the water quality standards of 6.5-9.0 s.u., as this range is more stringent than other applicable standards. This limitation is the same as that contained in the previous permit and is imposed upon the effective date of this permit. 4. Selenium a. Discharges to stream segments subject to the selenium TMDL — The EPA approved a selenium TMDL for the Gunnison River and Tributaries, Uncompahgre River and Tributaries, in February 2011. The TMDL affects non -attainment portions of 12 stream segments in these water sheds. Currently, sand and gravel facilities discharge to 4 segments included in this TMDL as follows; Lower Gunnison- COGULG01, COGULG02 North Fork of the Gunnison- COGUNF03 Uncompahgre River- COGUUN04b The Division will implement a waste load allocation (WLA) in the permit certifications for facilities discharging within the segments listed in the TMDL consistent with the requirements and assumptions of the TMDL. In addition, consistent with Regulation 61.8(2)(i), all pollutants limited in permits shall have limitations, standards or prohibitions expressed in terms of concentration and mass or concentration and flow. Therefore, for facilities that are subject to a mass -based WLA for selenium, the Division may also implement a concentration -based limitation for selenium in the permit certification, based on a quantitative reasonable potential (RP) analysis as described in Part VI.A.4.i. For existing sand and gravel dischargers, the mass -based WLA listed in the TMDL for each segment is noted as `WLA Sand and Gravel' or `WLA' depending on the segment. A separate allocation for each facility was not assigned in the TMDL. Rather, to allow flexibility in implementation, the WLA for all sand and gravel facilities on a given segment is listed collectively, as one allocation (lbs/day). Thus, where more than one sand and gravel discharger is present on a segment, implementation of limitations for specific dischargers may be based on, or adjusted from, the design flow of the facility at the time of the TMDL, and the presence or absence of other sand and gravel dischargers on the segment since the development of the TMDL. For new sand and gravel dischargers, loading allocations may be based on the collective allocation within the TMDL, the `WLA Reserve,' where applicable, or the water quality standard will be applied end of pipe. For all facilities, concentration -based limitations may be based on mixing zone considerations, where consistent with the TMDL. The TMDL notes that in some months certain segments may be in attainment (assimilative capacity is available) of the standard. As a result, the concentration -based limitations in these months may incorporate dilution, where available, using the monthly low flows documented in the TM DL. b. Discharges to 303(d) waters listed for selenium — Consistent with Division practice, this permit establishes monitoring requirements for these pollutants until such time as the TMDL(s) is complete and waste load allocations have been determined. The Division will require sampling and reporting of selenium data for discharges to 303(d) listed waters impaired for selenium. At a minimum, the sampling and reporting will be a "monitor and report" requirement. The Division may determine whether compliance with numeric effluent limitations is also required, on a case -by -case basis. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 35, Permit No. COG500000 5. Site Specific Organics, Inorganics, and Metals — The Division may make a case -by -case determination as to whether organics, inorganics, and metals are potential pollutants of concern that must be limited and/or monitored to protect the classified uses assigned to the receiving water. The case -by -case determination will be made based on the chemicals used in the treatment process, pollutants of concern for the industrial sector, the potential for characterization of the mine dewatering water to change due to locations of contaminant plumes (such as Leaking Underground Storage Tanks, Corrective Action sites, Voluntary Clean - Up sites, Superfund site, etc.), and data used to characterize the mine water. a. Discharges to 303(d) waters listed for arsenic, iron and manganese: The Division may require sampling and reporting of iron and manganese data for discharges authorized under this permit, as they have been identified as pollutants that dewatering activities can increase in pollutant concentration and loading due to their presence in the dewatering environment. The Division also considered requiring sampling and reporting of arsenic data for discharges to 303(d) waters listed for arsenic, since arsenic is also present in the dewatering environment, it can be affected by the discharge activity. Due to the uncertainty in the underlying standard and the limitation of `current conditions' for facilities existing prior to June 2013, the Division decided not to impose this requirement for this permit term. The effluent data collected during the course of this permit term will be used to make a new reasonable potential determination at the time of permit renewal in accordance with Clean Water Policy 1, Determination of the Requirement to Include Water Quality Standards -Based Limits in CDPS Permits Based on Reasonable Potential." The limitations for organics, inorganics, and metals are based upon the water quality standards contained in Regulation 31 and the basin regulations (Regulations 32-38). Standards for metals in the basin regulations that are shown as Table Value Standards (TVS) must be derived from equations that depend on the receiving stream hardness or species of fish present. These equations can be found in the basin regulations (Regulations 32-38). The effluent data collected during the course of this permit term will be used to make a new reasonable potential determination at the time of permit renewal in accordance with Clean Water Policy 1, Determination of the Requirement to Include Water Quality Standards -Based Limits in CDPS Permits Based on Reasonable Potential." 6. Electrical Conductivity (EC or Specific Conductivity) - Consistent with the discussion at A.3.a of this section, reporting for this parameter will be included in the permit certification. 7. Whole Effluent Toxicity (WET) Testing — The Division anticipates that the majority of discharges from sand and gravel facilities will not require WET testing; however, some discharges covered under this general permit may exhibit whole effluent toxicity based on the potential pollutant concentrations in the discharge (e.g., chemical additive use, or treatment or production processes that add pollutants to the discharge). Therefore, WET monitoring requirements or limitations may be imposed in the permit certification, on a case -by -case basis. For most certifications covered by this permit, a mixing zone is not applicable, and the low flow is considered to be zero. Therefore, consistent with the Division WET policy [Implementation of the Narrative Standard for Toxicity in Discharge Permits Using Whole Effluent Toxicity (Sept 30, 2010)], chronic WET testing will generally be applied in the permit certification. The WET dilution series will be specified in the certification, and will be 0% effluent (control), 20%, 40%, 60%, 80%, and 100% (effluent) for facilities for which a mixing zone is not applicable. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 36, Permit No. COG500000 However, on a site -specific basis, the Division may apply acute WET testing requirements in the permit certification, consistent with the Division WET policy referenced above, for facilities that demonstrate to the Division that they qualify for acute WET testing. The permittee should read the WET testing section of Part I.D and Appendix B of the permit carefully, as this information has been updated in accordance with the Division's updated WET policy, Implementation of the Narrative Standard for Toxicity in Discharge Permits Using Whole Effluent Toxicity (Sept 30, 2010). These sections of the permit outline the test requirements and the required follow-up actions the permittee must take to resolve a toxicity incident. The permittee should also read the above mentioned policy, which is available on the Permit Section website. The permittee should be aware that some of the conditions outlined above may be subject to change if the facility experiences a change in discharge, as outlined in Part II.A.2. of the permit. Such changes shall be reported to the Division immediately. C. Parameter Speciation 1. Total / Total Recoverable Metals (EXCEPT Arsenic) For standards based upon the total and total recoverable methods of analysis, the limitations are based upon the same method as the standard. 2. Dissolved Metals / Potentially Dissolved For metals with aquatic life -based dissolved standards, effluent limits and monitoring requirements are typically based upon the potentially dissolved method of analysis, as required under Regulation 31, Basic Standards and Methodologies for Surface Water. Thus, effluent limits and/or monitoring requirements for these metals will be prescribed as the "potentially dissolved" form. 3. Dissolved Iron and Dissolved Manganese if WS based The dissolved iron and chronic manganese standards are drinking water -based standards. Thus, sample measurements for these two parameters must reflect the dissolved fraction of the metals. 4. Fluoride if WS based The fluoride standard is a drinking water -based standard. Therefore, to conservatively protect drinking water uses, sample measurements for this parameter must reflect the total fluoride method. VII. ADDITIONAL TERMS AND CONDITIONS A. Monitoring Effluent Monitoring — Effluent monitoring is required as shown in the general permit document. Refer to the permit certification for locations of monitoring points. Monitoring requirements have been established in accordance with the frequencies and sample types set forth in the Baseline Monitoring Frequency, Sample Type, and Reduced Monitoring Frequency Policy for Industrial and Domestic Wastewater Treatment Facilities. B. Reporting Discharge Monitoring Report — Facilities authorized under this permit must submit Discharge Monitoring Reports (DMRs). The final permit includes the requirement for electronic submission of DMRs to the division. Prior to December 21, 2016, the permittee may elect to electronically submit DMRs instead of mailing paper DMRs by using the EPA's Net-DMR service. Starting on December 21, 2016, the permittee must electronically report DMRs by using the EPA's Net-DMR service unless a waiver is granted in compliance with 40 CFR 127. For those facilities subject to a WLA and associated concentration based WQBEL in the permit certification, DMRs shall be submitted on a monthly basis to assure loading calculations are as accurate as possible. DMRs shall be submitted on a quarterly basis for all other facilities. These reports should contain the required summary of the test COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 37, Permit No. COG500000 results for all parameters and monitoring frequencies identified in the permit certification. See the permit, Part I.F, for details on such submission. Many facilities statewide are required to submit monthly DMRs, though the practice for the sand and gravel industry has been quarterly submission to reduce the burden to the permittees. For sand and gravel facilities subject to a selenium WLA, the increased DMR burden (monthly) is necessary to incorporate monthly variations in dilution that are included in the TMDL, which may result in monthly effluent limitations. The Division considered requiring monthly DMR submittal to improve the accuracy of salinity loading for facilities discharging to the Colorado River basin. However, the Division found that more accurate salinity loading information can be obtained by requiring permittees to report quarterly total flow as well as a TDS concentration. Special Reports — Special reports are required in the event of an upset, bypass, or other noncompliance. Please refer to Part ILA. of the permit for reporting requirements. Permittees are no longer required to submit these reports to the US Environmental Protection Agency Region VIII. C. Spills Spill requirements apply to materials spilled that result in their presence in the discharge authorized under this permit. Spills that may cause pollution of state waters that are not discharged through an outfall authorized under this general permit are not within the scope of this general permit and are required to be reported in accordance with the Colorado Water Quality Control Act 25-8-601(2), since the Division views these actions as not authorized under the scope of a discharge permit. Additional information regarding reporting of unauthorized spills is contained in the Divisions Guidance for Reporting Spills. D. Signatory and Certification Requirements Signatory and certification requirements for reports and submittals are discussed in Part I.F.4 of the permit. E. Compliance Schedules Existing dischargers may be granted compliance schedules for any new effluent limitations applicable to the discharge. Some items requiring a compliance schedule may require an individual permit. F. Economic Reasonableness Evaluation Section 25-8-503(8) of the revised (June 1985) Colorado Water Quality Control Act required the Division to "determine whether or not any or all of the water quality standard based effluent limitations are reasonably related to the economic, environmental, public health and energy impacts to the public and affected persons, and are in furtherance of the policies set forth in sections 25-8-192 and 25-8-104." The Colorado Discharge Permit System Regulations, Regulation No. 61, further define this requirement under 61.11 and state: "Where economic, environmental, public health and energy impacts to the public and affected persons have been considered in the classifications and standards setting process, permits written to meet the standards may be presumed to have taken into consideration economic factors unless: 1. A new permit is issued where the discharge was not in existence at the time of the classification and standards rulemaking, or 2. In the case of a continuing discharge, additional information or factors have emerged that were not anticipated or considered at the time of the classification and standards rulemaking." The evaluation for this permit shows that the Water Quality Control Commission, during their proceedings to adopt the basin regulations, considered economic reasonableness. Furthermore, no new information has been presented regarding the classifications and standards. Therefore, the water quality standard -based effluent limitations of this permit are determined to be reasonably related to the COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 38, Permit No. COG500000 economic, environmental, public health and energy impacts to the public and affected persons and are in furtherance of the policies set forth in Sections 25-8-102 and 104. If a party that desires coverage under this general permit disagrees with this finding, pursuant to 61.11(b) (ii) of the Colorado Discharge Permit System Regulations, they should submit all pertinent information to the Division during the public notice period. VIII. PUBLIC NOTICE COMMENTS - See Appendix B for Division Response to Public Comments document. IX. REFERENCES A. Colorado Department of Public Health and Environment, Water Quality Control Division Files, for Permit Number COG500000. B. Basic Standards and Methodologies for Surface Water, Regulation No. 31, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective January 31, 2013. C. Classifications and Numeric Standards for Arkansas River Basin, Regulation No. 32, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective December 31, 2013. D. Classifications and Numeric Standards for Upper Colorado River Basin and North Platte River (Planning Region 12), Regulation No. 33, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective September 30, 2013. E. Classifications and Numeric Standards for Upper San Juan River and Dolores River Basins, Regulation No. 34, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective September 30, 2013. F. Classifications and Numeric Standards for Gunnison and Lower Dolores River Basins, Regulation No. 35, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective September 30, 2013. G. Classifications and Numeric Standards for Rio Grande Basin, Regulation No. 36, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective December 31, 2013. H. Classifications and Numeric Standards for Lower Colorado River Basin, Regulation No. 37, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective September 30, 2013. I. Classifications and Numeric Standards for South Platte River Basin, Laramie River Basin, Republican River Basin, Smoky Hill River Basin, Regulation No. 38, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective September 30, 2013. J. Colorado Discharge Permit System Regulations, Regulation No. 61, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective January 30, 2012. K. Regulations for Effluent Limitations, Regulation No. 62, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective July 30, 2012. L. Colorado River Salinity Standards, Regulation No. 39, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective August 30, 1997. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 39, Permit No. COG500000 M. Colorado's Section 303(d) List of Impaired Waters and Monitoring and Evaluation List, Regulation No 93, Colorado Department of Public Health and Environment, Water Quality Control Commission, effective April 30, 2010. N. Antidegradation Significance Determination for New or Increased Water Quality Impacts, Procedural Guidance, Colorado Department of Public Health and Environment, Water Quality Control Division, effective December 2001. O. Memorandum Re: First Update to Antidegradation) Guidance Version 1.0, Colorado Department of Public Health and Environment, Water Quality Control Division, effective April 23, 2002. P. Determination of the Requirement to Include Water Quality Standards -Based Limits in CDPS Permits Based on Reasonable Potential Procedural Guidance, Colorado Department of Public Health and Environment, Water Quality Control Division, effective December 2013. Q. The Colorado Mixing Zone Implementation Guidance, Colorado Department of Public Health and Environment, Water Quality Control Division, effective April 2002. R. Baseline Monitoring Frequency, Sample Type, and Reduced Monitoring Frequency Policy for Domestic and Industrial Wastewater Treatment Facilities, Water Quality Control Division Policy WQP-20, May 1, 2007. S. Implementing Narrative Standard for Toxicity in Discharge Permits Using Whole Effluent Toxicity (WET) Testing. Colorado Department of Public Health and Environment, Water Quality Control Division Policy Permits -1, September 30, 2010. T. Code of Federal Regulations, 40 CFR Part 132, Water Quality Guidance for the Great Lakes System, Office of the Federal Register, Government Printing Office, effective July 24, 1975 and as amended. U. Code of Federal Regulations, 40 CFR Part 443, Paving and Roofing Materials (Tars and Asphalt) Point Source Category, Office of the Federal Register, Government Printing Office, effective July 1, 2015. V. Code of Federal Regulations 40 CFR Part 436, Mineral Mining And Processing Point Source Category Point Source Category, Office of the Federal Register, Government Printing Office, effective October 16, 1975 and as amended. W. McKee, Jack and Harold Wolf, Water Quality Criteria ("California Book") Sacramento, State of California Water Resources Control Board, 2nd Ed. 1963 X. Environmental Protection Agency, Office of Wastewater Management, Water Permitting 101. Available at: https://www3.epa.gov/npdes/pubs/101pape.pdf. Last accessed October 10, 2016. Y. Environmental Protection Agency. Final Water Quality Guidance for the Great Lakes System. 60 Fed. Reg. 15366, March 23, 1995. Z. Environmental Protection Agency Region VIII. Intake Credits. Memo Ref: 8WM-WQ, March 2, 1992. COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division Fact Sheet — Page 40, Permit No. COG500000 APPENDIX A — Description of Standard Industrial Classification (SIC) Code Major Group 14 facilities Major group 14 includes establishments primarily engaged in mining or quarrying, developing mines, or exploring for n onmetallic minerals, except fuels. Dimension Stone (SIC code 1411) - Establishments primarily engaged in mining or quarrying dimension stone. Also included are establishments engaged in producing rough blocks and slabs. Crushed and Broken Limestone (SIC code 1422) - Establishments primarily engaged in mining or quarrying crushed and broken limestone, including related rocks, such as dolomite, cement rock, marl, travertine, and calcareous tufa. Crushed and Broken Granite (SIC code 1423) - Establishments primarily engaged in mining or quarrying crushed and broken granite, including related rocks, such as gneiss, syenite, and diorite. Crushed and Broken Stone, Not Elsewhere Classified (SIC code 1429) - Establishments primarily engaged in mining or quarrying crushed and broken stone, not elsewhere classified. Construction Sand and Gravel (SIC code 1442) - Establishments primarily engaged in operating sand and gravel pits and dredges, and in washing, screening, or otherwise preparing sand and gravel for construction u ses. Industrial Sand (SIC code 1446) - Establishments primarily engaged in operating sand pits and dredges, and in washing, screening, and otherwise preparing sand for uses other than construction, such as glassmaking, molding, and abrasives. Kaolin and Ball Clay (SIC code 1455) - Establishments primarily engaged in mining, milling, or otherwise preparing kaolin or ball clay, including china clay, paper clay, and slip clay. Clay, Ceramic, and Refractory Minerals, Not Elsewhere Classified (SIC code 1459) - Establishments primarily e ngaged in mining, milling, or otherwise preparing clay, ceramic, or refractory minerals, not elsewhere classified. Potash, Soda, and Borate Minerals (SIC code 1474) - Establishments primarily engaged in mining, milling, or otherwise preparing natural potassium, sodium, or boron compounds. Phosphate Rock (SIC code 1475) - Establishments primarily engaged in mining, milling, drying, calcining, sintering, or otherwise preparing phosphate rock, including apatite. Miscellaneous Nonmetallic Minerals, Except Fuels (including Graphite) (SIC code 1499) - Establishments primarily e ngaged in mining, quarrying, milling, or otherwise preparing nonmetallic minerals, except fuels. This industry includes the shaping of natural abrasive stones at the quarry. APPENDIX B — See Division Response to Public Comments document for Appendix B. Varra Companies, Inc. s/sty 00 f:' elpf)f> %t Lot,, Office of Special Projects 8120 Gate street rederick, Colorado 80516 Tele hone 303 i 666-6657 Fax 303 666-6743 Statement of Understanding Landowner of Adjacent Structure Statement: Our notarized signature below testifies we have been provided with and opportunity to review: i a Stability Analysis Report pertaining to the proposed Two Rivers Sand, Gravel and Reservoir Project Regular Impact (112) Permit Application W2022-013.: 3.: and, a Map showing the approximate relationship of our property and the potential for any qualified significant. valuable and permanent man-made structure(s), which may occur within 200 feet of lands affected ‘ it zin the proposed Two Rix Syr- Said, Gravel and Resen of r Project Regular Impact (112) Permit Application M-2022-{13. Upon review of the available materials reference here or the attending Public Notice; Arid, understanding the relationship of any s ' `cant, valuable and permanent man made structures under our ownersh p and which may stand tw-ithin 200 feet of lands affected within the proposed 1 e\ o Rivers S aniL Gravel and ResellReservoir Project a Regular I m pact (112) Permit Application M 2022 -U13,; Further, by our signatures, as notarized below, we concur that planned activities detailed in the application for permit M -2022-013.; do not impact our qualil-ied significant, valuable and permanent adjacent man-made structures: and to assure you that in the unlikely event damage occurs to such structures as a direct result of authorized active operations, those damages will be compensated for by the Operato consistent th established law. Signature of Adjacent Landowner tfav, Tint Name State of County of ,r, /0,4 - --- ill orate ret‘ tAL) J 55. The foregoing, instrument was acknowledged befo by LpwIsl � tt Company or Corporation ♦.. -et liew LORR; ANN CARLSON NOTARY PUBLIC STATE OF COLORADO eft, 7 Date 10"" ,—-- 'Pi.J / '�� riletietc me this day .ie wit, c cx ct for j (1 V fl\ 1T&V1 • Title 1 (---Ce1/4._ ?frk-AA, Dc in 1 4' Notary Public My Commission expires: NOTARY ID - I MY COMMISSION EXPIRES MARCH 42, 2025 2 Varra Companies, Inc. Office of Special Projects 8120 Oa2eStreet Frederick, Colorado 80516 Telephone (?0 ; 666-665.7 Fax (303 666.4743 Statement of Under tan in g Landowner of Adjacent Structure Statement: Our notarized signature below testifies we have been provided with and opportunity to review: I) a Stability ity Analysis Report pertaining to the proposed Two Rivers Sand. Gravel and Reservoir Project — Regular Impact (1.12) Permit Application rM-2 ??-013.; and, 2) a Map showing the approximate relationship of our property and the potential for any qualified significant, valuable and permanent man-made structure(s), which may occur within 200 feet of lands affected within the proposed Two Rivers Sand, Gravel and Reservoir Project — Regular Impact (112) Permit Application M-2022-013. Upon review of the available materials reference here or the attending Public Notice; And, understanding the relationship of any significant, valuable and permanent man-made structures under our ownership and which may stand within 200 feet of lands affected within the proposed Two Rivers Sand, Gravel and Reservoir Project — Regular Impact (112) Permit Application M -2022M13.: Further, by our signatures, as notarized below, we concur that planned actinties detailed in the application for permit M -2022--0B.; do not impact our qualified significant., valuable and permanent adjacent man-made structures: and to assure you that in the unlikely event damage occurs to such structures as a direct result of authorized active operations, those damages will be compensated for by the Operator, con istent wit estabhshcd l '. 4 I Sign tur of' Adjacent Larcdowner sl Print Name Azi end et-knn q d- '1► d State of CcCciett.t, dd County of ) ss. c/c Date The foregoing instrument was acknowledged before me this Sday of by ' ( � , r.or it im:), t‘ —1 71 A.; — ). Title Jr` Company or Corporation 2022 AL la w , 2021 for tL' J / (;,*J7 out t re Notary Public l` di, ree My Commission expires: - - J. ' " . . 2 91c08 03 NDftBOJ 4d ales — • C MSS ISS it. W s a lass .err els r. 0 a w3... asr ISO WASSIS MIS r s a- 0.0 c 73 PC) frn >1f rn rrs rn y) z n 1n tr- 0 CO O CO sue " r 0 44 1 coo O1 —rut rim CO M Z C CO r 0 t XI i s ;;+.y;i L4 i. i C- v :lnc'r Ci 14 $c co O -Ace � ..It ont leg 1,3 it'll thi ?vac' O Ill " hit 111 iv Q►I rip Vana Companies, Inc. Office of Special Projects 8120 Gaee Street Frederick. Colorado 80516 Teter -111 (303) 666-6657 Fax (3 3) 6664743 Statement of Understanding Landowner of Adjacent Structure Statement: Our notarized signature below testifies ies we have been provided with and opportunity to review: I} a Stability Analysis Report pertaining to the proposed Two Rivers Sand, Gravel and Reservoir Project - Regular Impact (112) Permit Application Ni 2022-013.; and, a Map showing die approximate relationship of our property and the potential for any qualified significant, valuable and permanent man-made structure(s), which may occur within 200 feet of lands affected within the proposed Two Rivers Sand, Gravel and Reservoir Project -- Regular Impact (112) Permit Application NI 2022 013. Upon review of the available materials reference here or the attendirg Public Notice; And, understanding the relationship of any siicant, valuable and permanent manmade structures under our ownership and which may stand within 200 feet of lands affected within the proposed Two Rivers Sand, Gravel and Reservoir Project - Regular Impact (112) Permit Application M-2022 013.; Further, by our signatures, as notarized below, we concur that planned activities detailed in the application for permit NI2022 013.; do not impact our qualified significant, valuable and permanent adjacent man made structures. and to assure you that in the unlikely event damage occurs to such structures as a direct result of authorized active operations, those damages will be compensated for by the O rat 6 r, consistent with established law. (f dr--_, I A b .� __= 5/612022 1011 Signature of Adjacent Landowner Date Marshall P. Brown Print Name State of Colorado � Arapahoe )ss. County of P } foregoingin instrument was f o thi d of 1 The - st h►ef re �e � a� by Marshall P. Brown General Manager for Aurora Water Company or Corporation Title CASEY LEE ROSSIAMI NOTARY PUBLIC STATE OF COLORADO NOTARY ID 20204017 or( iSssati guns arson _ - -J My Commission expires: 131 r 20'??-, .i) -� L+ 2 w ass .mss + • r+ w•sm. ara w••is are mita ime ale r •rra• Wag cora it rr� van sae w - pr was .rs cif w a Sala !i• a a t• is rt 4 n ctod fig Q ED 01 fai J 4- a m co a' fD or 0 CV fl1 01.149 a• "4 oo E s sto 1.. Pt on, ilaw V 0 art n siJ ;ma Pr3 C 0 rob It VUO2 fV 1O AU) r M C 1 1 4 1 • Ys - I % F Car-% s 4 rtreb ret tie ` 1 z I Varra Companies,Inc. Office ofSpecial Projects 8120 Gage Street Frederick. Colorado 80516 Tel hoe 0303) 040-6657 Fax (303) 664-6743 Statement of Understanding Landowner of Adjacent Structure Statement: Our notarized signature below testifies we have been provided with and opportunity to review: 1) a Stability Analysis Report pertaining to the proposed Two Rivers Sand, Cray d and RL: e r 7oir Project - Regular Impact X112) Permit Application -2022-0I3.; and, 2) a Map showing the approximate relationship of our property and the potential for any qualified significant, valuable and permanent man-made structure(s), xvhich may occur eN'ithin 200 feet of lands affected within the proposed Two Rivers Sand, Gravel and Reservoir rrt)jcLt - Regular impact (112) Permit Application NI -2022-0B. Upon review of the available materials reference here or the attending Public Notice: And, understanding the relationship of any significant. valuable and permanent man made structures under our ownership and which may stand within 200 feet of lands affected within the proposed I wa Rivers Sand, Gravel and Reservoir Project -- Regular Impact (112) Permit Application M-2072 013.; Further, by our signatures, as notarized below, we concur that planned activities detailed in the application for permit M-2022-0134 do not impact our qualified significant, valuable and permanc in adjacent man-made structures: and to assure you that in the unlikely event damage occurs to such structures as a direct result of authorized active operations, those damages will be compensated for by the orator} consistent with established law. igntu re of Adjacent Landowner IL? Clicatitt#came--- Print Natant' County of fr y Date 20,7 /Ger fatrini LPL Cts The foregoing instrument was acknowledged before me this to by -1-544e„. Lerflat Title Company or C nr;nnration 1.----CAIRekEEGLEFF-1 NOTARY PUBLIC STATE OF COLORADO NOTARY IDI99640 95 MY COOMISSION WIRES 01121 /202 at' My Commission expires: le S y,Y Lit 2t 2: r, a fl gl tart ci :w Dt Yeti g i r es - 4 4 it W • • mar • Actint 0.111. • r. 40.14%1inaraf ljetjt - 4 J i h • a 4- U it •e4 . t -L.fr'ialtr *4 4• .4 O-7.r� 41•; • �L2 • ,C-` .: c 0 C I 4 to sr c tan E reset- 800 al 0 V gni w c sk e A w zaNcp mat a id N 0 M S --Aam 3c)0 3 ra) ``ep C eats tams puma teem far Amami oafs mown b• p ONO* .mom 4444 ogee, Mar sem arm wr. .tw etala 114.4, Its 1 MIS seeks IMMO Sat ..4 Sra. rna seaRma MIN! OMEN MOURNER! MOWS A : t �•' a ( * _ �- = ae ; : s Varra Companies, Inc. Office of Special Projects 8120 Gage Street Frederick. Colorado 80516 Telephone (303) 666-6657 Fax (303) 666-6743 Statement of Understanding Landowner of Adjacent Structure Statement: Our notarized signature below testifies we have been provided with and opportunity to review: 1) a Stability Analysis Report pertaining to the proposed Two Rivers Sand, Gravel and Reservoir Project — Regular Impact (112) Permit Application M-2022-013.; and, 2) a Map showing the approximate relationship of our property and the potential for any qualified significant, valuable and permanent man-made strueture(s), which may occur within 200 feet of lands affected within the proposed Two Rivers Sand, Gravel and Reservoir Project — Regar Impact (112) Permit Application M-20?2-013. Upon review of the available materials reference here or the attending Public Notice., And, understanding the relationship of any significant, valuable and permanent man-made structures under our ownership and which may stand within 200 feet of lands affected within the proposed Two Rivers Sand. Gravel and Reservoir Project — Regular impact (112) Permit Application M-2022--013.; Further, by our signatures, as notarized below, we concur that pi ed activities detailed in the application for permit M -2o22-013.; do not impact our qualified significant, valuable and permanent adjacent man-made structures: and to assure you that in the unlikely event damage occurs to such structures as a direct result of authorized active operations, those damages will be compensated for by the Operator, consistent with established law. Signature of Adjacent Landow*nereb\ss5:13/44-Tswi Print Name State of Ccs\oct C' sc. County of �, u Q_\ Date The foregoing instrument was acknowledged before me this ' \ day of inc\(.3,\--1 , At t rSc _ � � - '4 - (a- e c:15; N for . ��-- �. Title Company or Corporation SAMANTHA SESLAR NOTARY PUBLIC STATE OF COLORADO Public 2022 ?2, cr-E) a a, My Commission expires:fl'2t/ 9/, 4 1.); p NOTARY ID 20144021533 MY COMMISSION EXPIRES MAY 29, 2026 2 �t tr.� i r '% rift 4 l3. es. sest V.4, %:t' 14aa 0 i i DENVER Co 802 U) 0 0 es 1:7-1 Ana Mit gimp as tN a C tN C arm St cm C Q .o. A C a I CN co fav Lu a.+ f ..r I t_! '. ,r. -• s *. • on fag It Gen c.nesj • c:›1° \test 01411124 S i▪ ms 4-....., Oulaleek Higue elelnye game newels .e..r ..lialo▪ r net w. Heats S ale • .tom` ..i.. . rye h . i. Sags tens Rea mak etli-a s.R Iron • -ts- lwry .4.n, .ter. .R .tr Mae tr ... ' -'-'-a. ..fir .ti S.dlwh Varra Companies, Inc. Office of Special Projects 8110 gage Street Frederick. Colorado 80516 Telephone (303 666-6657 Fax (303) 666-6743 Statement of Understanding Landowner of Adjacent Structure Statement: Our notarized signature below testifies we have been provided with and opportunity toreview: 1) a Stability Analysis Report pertaining to the proposed Two Rivers Sand, Gravel and Reservoir Project -- Regular Impact (112) Permit Application M-2022 -013.; and, 2) a Map showing the approximate relationship of our property and the potential for an)' quaffed significant, valuable and permanent man-made structure(s), which may occur within 200 feet of lands affected ti ithin the proposed Two Rivers Sand, Gravel and Reser%n r Project - Regular impact (112) Permit Application N4-2022-013. Upon review of the available materials reference here or the attending Public Notice; And, understanding the relationship of any signii icont, valuable and permanent man-made structures under our ownership and which may stand within 200 feet of lands affected within the proposed Two lugs sand, Gravel and Reservoir Project - Regular impact (112) Permit Application M-2022--013.; Further, by our signatures, as notarized below, we concur that planned activities detailed in the application for permit M-2022-013., do not impact our qualified significant, valuable and permanent adjacent man-made structures: and to assure you that in the unlikely event damage occurs tosuch structures as a direct result of authorized active operations, those damages will he compensated for by the Operator, consistentwith established law. Sighature of Adjacent Landowner I r It 161 -4C —k— -. 1 i I e ..� 1 s t ! i y 1 Print Name State of County of LU/Of j . d 1 SS. V>, Date The foregoing instrument was acknowledged before me this L day of y Company or Corporation ROX ANNE GARCIA -s NOTARY PUBLIC STATE OF COLORADO NOTARY ID 1997 261 MY COMM I° PIPES MAY 02, 2025 t 1)/Cl lcc'g Title I for f; •f1 Nota y Public My Commission expires: ,2022 „?022, Coe, ) v 1 1.4 0 kid 'U lrbl tar+ AY 20 22 VORA (49 ccths Fs Og: <0 5 a1 z t11 QJ ; c Val CC tee in '44 apatite t1y rag dczt • Eh guilt ► try„ilrfiltrlfflit .Ps K EO �Nf NOTIFICATIONS STATUS: X=recd /T=recd-via-tracking /O=null #: PARCEL #: I PARCEL OWNER OF RECORD I ADDRESS ADDRESS I CITY STATE I ZIP CODE I SEE SRUCTURES/ROW/EASEMENTS, BELOW I Initial I Resend 1 105704000024 RAPTOR MATERIALS LLC 8120 GAGE ST. FREDERICK CO 80534 PDC ENERGY INC. Self Notified 2 105704000025 " " 14822 HIGHWAY 396 - EVANS " " PDC ENERGY INC. 3 105703000026 " " " " 4 105703000027 " " " " " 5 095934300006 " " " " NOBLE ENERGY INC. 6 095933000007 " " 14822 HIGHWAY 396 - EVANS " " 7 105704000003 SHABLE HOMESTEAD LLC 12701 STATE HWY. 60 MILLIKEN CO 80543-9308 PDC ENERGY INC. X 8 095933000023 JDLB FARM LLC 7251 W 20TH ST., BLDG L STE 200 GREELEY CO 80634-4626 PDC ENERGY INC. X " NOBLE ENERGY PRODUCTION 9 095933000024 X 10 095933000009 JOYCE J ALLELY 17 DOS RIOS GREELEY CO 80634-9502 11 095933000008 ii ii"ii" 12 095933400029 i. i."i." PDC ENERGY INC. 13 095933400030 " " " " 14 095934400010 i." " " " PDC ENERGY INC. 15 095934300001 TAMMY SUE CAMENISCH 14898 COUNTY ROAD 396 MILLIKEN CO 80543-9305 X 16 095934300005 " 14898 COUNTY ROAD 396 14898 COUNTY ROAD 396 - EVANS MILLIKEN " " 17 095934400036 CITY OF AURORA CITY MANAGER 15151 E. ALAMEDA PKWY. AURORA CO I 80012 X 18 095934400035 PDC ENERGY INC. 19 105703300004 ii" " ii " " NOBLE ENERGY INC. 20 105704400001 " " " " " " NOBLE ENERGY INC. 21 105704000023 " " " " " " 22 105703100045 DIXIE WATER LLC. 400 POYDRAS ST., STE 2100 NEW ORLEANS LA 70130-3282 X 23 105703200041 ROBERT I LEMON 1675 BROADWAY, STE. 1275 DENVER CO 80202-4602 O X 24 105703300007 4848 THOMPSON PKWY, STE. 410 JOHNSTOWN CO 80534-6511 T JBS FIVE RIVERS CATTLE FEEDING LLC 25 105704300028 SW SPRUCE MOUNTAIN LLC 812 GRAVIER ST., STE 360 NEW ORLEANS LA 70112-1408 T 26 105704300030 AGGREGATOR LLC 812 GRAVIER ST., STE 360 14240 COUNTY ROAD 396 - WELD NEW ORLEANS LA 70112-1408 C/O RUBY ALVAREZ T #: RECEPTION U/ID I OWNER: STRUCTURE - EASEMENT - ROW I ADDRESS ADDRESS I CITY STATE I ZIP CODE I TELEPHONE #: I 26 92305 WCR 396 CITY OF EVANS 1100 37TH ST. EVANS CO 80620 970-475-1170 X ATTN: JIM BECKLENBERT, CITY MGR. 27 149698 EVANS TOWN DITCH CITY OF EVANS PUBLIC WORKS 1100 37TH ST. EVANS CO 80620 970-475-1170 X 28 WCR 396 TOWN OF MILLIKEN MILLIKEN TOWN HALL; 1101 BROAD ST. MILLIKEN CO 80543 970-587-4331 X ATTN: TIM SINGWALD, TOWN ADM. 29 90538 WELD COUNTY DEPT. OF PUBLIC WORKS JAY MCDONALD, DIRECTOR P.O. BOX 758 GREELEY CO 80632 970-4000-3750 X3750 X 30 Overhead @ WCR 396 CENTURY LINK 2505 1ST AVE. GREELEY CO 80631 855-891-4083 T aka, Lumen -X ATTN: DAN ORTEGA, ENGINEER III 31 Overhead @ WCR 396 XCEL ENERGY 3737 WEST 10TH ST. GREELEY CO 80632 970-395-1239 T ATTN: RIGHT OF WAY DEPT. 32 BURIED LINE @ 396 CENTRAL WELD COUNTY WATER DISTRICT 2235 SECOND AVENUE GREELEY CO 80631 970-352-1284 X ATTN: RIGHT OF WAY DEPT. 33 BURIED LINE @ 396 835 E. STATE HWY. 56 BERTHOUD CO 80513-9237 970-532-2096 X LITTLE THOMPSON WATER DISTRICT ATTN: RIGHT OF WAY DEPT. 34 2410746 SNYDER OIL CORPORATION 777 MAIN ST., STE 2500 FORT WORTH TX 76102 817-338-4043 T ATTN: RIGHT OF WAY DEPT. "ii ii1625 BROADWAY, STE. 2090 DENVER CO 80202 - T "i. i.1625 BROADWAY, STE. 2200 DENVER CO 80202 303-592-8500 T 35 351023 NOBLE ENERGY PRODUCTION, INC. GREELEY CO 80631 970-304-5000 T ATTN: RIGHT OF WAY DEPT. 2115 117TH AVE. ONE WELL NE SEC. a.k.a., CHEVRON " 1001 NOBLE ENERGY WAY HOUSTON TX 77070 800-220-5824 X 36 3537429 DCP MIDSTREAM 3026 4TH AVE. GREELEY CO 80631 970-356-9700 X ATTN: RIGHT OF WAY DEPT. 3944956 X 3944957 iiX 37 2003166 NATURAL GAS ASSOCIATES 621 17TH ST., STE. 2010 DENVER CO 80293 303-623-0747 T -Arriving Late ATTN: RIGHT OF WAY DEPT. 38 CAUTIONARY NOTICE ANADARKO PETROLEUM 1201 Lake Robbins Dr. THE WOODLANDS TX 77380 832-636-1000 X ATTN: RIGHT OF WAY DEPT. 39 3525268 KERR-MCGEE OIL & GAS ONSHORE LP " " " " " X ATTN: RIGHT OF WAY DEPT. 40 3525268 K.P. KAUFMAN COMPANY, INC. 1675 BROADWAY; 28TH FLOOR DENVER CO 80202 303-825-4822 T ATTN: RIGHT OF WAY DEPT. 41 2058722 PANHANDLE EASTERN PIPE LINE COMPANY 8111 WESTCHESTER DR., STE. 600 DALLAS TX 75225 800-275-7375 X ATTN: RIGHT OF WAY DEPT. 42 SEE ABOVE XCEL ENERGY 1500 6TH AVE. GREELEY CO 80631 970-395-1239 O X ATTN: RIGHT OF WAY DEPT. 43 BALANCE OF WELLS PDC ENERGY INC. 1775 SHERMAN ST.; STE.300 DENVER CO 80203 970-506-9272 X ATTN: RIGHT OF WAY DEPT. 44 Overhead @ WCR 396 POUDRE VALLEY REA 7649 REA Parkway FORT COLLINS CO 80528 800-432-1012 X ATTN: RIGHT OF WAY DEPT. 45 AS LABELED WESTERVELT ECOLOGICAL SERVICESS 7348 S. ALTON WAY, STE9-D CENTENNIAL CO 80112 720-955-3029 X ATTN: RIGHT OF WAY DEPT. WsWWI D.ta" Permit Number Latitude longitude Owner Permit Status Construction Date Permit Category Usels) - \ 13350-11-1140.35 •101.76911 005IdO6 ESTATES y1TTR CO Well Constructed 10/11/L989 General Purpose irrigation • 27I}R 40 -101785 SHAYLEtALVAI Well Constructed 6/20/1955 GeneralPu Ini atomd3°i3•R'R se 40.342343 -104.782 VARRACOMPANIESINC IVARRA, GARRETT) Well Constructed 11/14/1989 General Purpose Uri', anon kill •304R 40.342642 100.78099VARNAC0MPANIESINCWARR&GARRET11 W_ellConsuusled W_3Q11952GeneralPurpose 320422- 40.339043 ' 104. /8S99 (Ai ARGEHOl.CIM / AGGREGATE INDUSTRIES Well Constructed _�Imgation 1/27/2021 Monitorin Observation Monitorin: Stun' lin74047••A 40 339404 r SORIN NATURAL RESOURCES PARTNERS U.C Well Constructed 5/12/1975 Residential Domestic DIME WATEA 11C Well Constructed V23/19 • General Purpose Irrigation . SORIN NATURAL RESOURCE PARTNERS U.C Will Constructed 2014 General Industnal _..__-----.. -.. ., _ .a.e.-.- r . - .. . f -s. ~ J f St al st ; r '' 1 ell- r` •1.Y it ....r, •• 1 !.' . R •else. OS 4a loo y • _. • �_. MALI IN tit 1 .r ~t•. tl-:-• L•— eair r }ter__. JJ Oil; _ �♦ , �.r... «i_: y a J '� r hz •`'fir, .r� ;" ,, ��.�tTaiYs' *Lf %a •� :. am• {� 1 4'• „' t—i. I_ .s- .'� al� ' *ton Tplitt• v • f .- z r fir. �t,',T i l ate, *�C�a �,_ . N,! - 0 t .. •• .. -•-J, ---- I Y. _ _. - ' - :a :i;1 _ _ - :.,-� ;.Y- ��..{ ••1� �5-Y..' ;No, . _ ' '�fi, �' - t: . Wit'''' i -. , I '' J),$ `y 1 ` 1 1 "y `e• - M - _ •� L _ . .'— 1 eh1 r • .r< _-- �1 .ate— -...... >. i ► i a ,.. : e ` ��•, �{ wE �w, r1' ...- ••x- a. _ - •.' . •-� . . . 1- ice♦• • T • 1 I t y ~"�/ \\ _ .. n -t - c r !I/ ��tr i' -.. .�r �r r'//-/ \ . _ .. ♦ \1\ I; r..t' It 1'.iLrr •r - Y+ .` . a t _ n - r Mir o _ .i , ` t s ITif.,•.Nfl• � �� - - I- J i 1 4 _ -- 1 _ , __ .._ . r, \, •' : !, %_-.f'erat*reta .r . N. w_ , r - t ' J -r i YV YWIY0YY.Y �. _ ..•••••-•a••1.••••• Ma - .4 • I" Itil »•-....-.. - '.-. - ... ._ -. DC E ►s-�' _ .r ...a.. .. .ra _ I _.a I P '1. I NI. " Eill E -1-- - r _ _ WW RUC Pjli C, f:I:,Y CVCRGt' •••,.r• ..r f _ S. YUMA ••• r.••was 4•• • rill._ Siaga.. i 111rr":lla .— _ I.Y' . , • . , , ,..gaol - J1_iisi r'�.>SS.a i.r.a.j r1N.at^.a f.a[_a. .. r., flan% Y•.•,•t•L-I'LL •_�-• NIR •••r.. .•. . • a � • ♦ !� "reit• .� -ow fr • .••\I•. �. ,. - , m. a ...ice _gall«. _ t - — . +,.ng..'14...44.„,„•••• i' �� A -1-.. I,ce N.A. a r .=...L.e.��.a I r .•'f�'_ as.•. a As _. -. .-.••..•_..r . _Y r ... _..4 •, fq !flat,J • 3.1.1 •�.. .... •w. -. __.. N.W f_.. .. a 2 fY lRL1-1,e Y! '-r 1", I r - _ . . IA M ., `• g -. .1 .I. i_•/ . r• • -• Y •Mir vrr• _ .. VM . ' .a •in.Y.w•1 • Ha. u,. . • ••. tta• Mn al •. - ffn.:- .Y 46 nat. - .•• _ _ -Y- ,^ , .� • I - eme_..n �• _. ._ .. awns; yip .,. .. - - -- am .., • .. ♦L"u •- _ - •-•• ,••••••••••••••. •,r�R--,rv•• .•,r • — •• 1 '•a ap AiM r �/\ _• ... • ''T.w•rrr... t. _t-r...t u. .._!•6.111=___ _:Y it w.tirr�. -S . w.w t- S 1..11N v .T I tl•S -iYL'�� •..,/•.♦.•P .`slur•/• 'a ••••••••••RL. P. ., 1 . Jn•1 i-.a.r..a_t r .a- �a.s i • 4N VII VAIlyiALS tom. coat °°°-�C' Two Rivers S a r d 'ravel sic Reservoir Pro 'c c : , NOTES Drown by A_ Jones ScA:E. ' inch - 463 +�=� Checkeden 1 °eEv50m4 22 •eaoa r!. %snot •►�i-.-w• oRmosG =xh1bi-, C- •Ex's;1ng Condil'ons Mop Christensen rn arY, �727V ' PAGE. 1.� -t.— . I a RAPTOR MATERIALS. L..: Wt. 41 •1\t` c,ttc.C. _G Y.JG as1g tat•••T•t tail n-Nt1 PRaxt:1 Two Rivers Sone, Crave and Reservoir Project ant" Exhibit C-2: Extraction Plar, Moo TEMP SOIL STOCKPILE LOCATION -PO55 PARKING & EQUIPMENT STORAGE (SUBS. TO CHANGE) "°'E' 234.06±Acres Basins Total + 5.60±Acre Wosh Pond ROW it Easements nol shown from Exhibit C-1, Existing Conditions Mop. we obso+ete a vacated Inca - 200 feat OAr_ 22 1.ebruory 2027 RE Vts OA 20 hovember 2022 PACE o' 1 "I's"' Iwo Rivers yard, Gravel Reservoir Project 234.06i Acres Rosins Total NAP tat VAIUALS. 'LC WA co* tiny 'iCO4Y cat as. wat.'s. :- @n—Nt• DRAWING- = xh;bi; F: Rcclama:'on P cn Map IDF PiPEE-SGIS.Ui ref Pin -.44.1.:.! ONL'` II IU'S .IHJL IUIiL LA .LMLN I RIGH S -OF -WA f SHOWN IN THIS EXHIBIT =. RECI AMAT rN PI AN MA;',ARE ANTIC PATE. TO RLMA NJ I f LII II IS• TOWN IN LXII ;iI I L-1. r EXIS"ING CONDIT ONS MAR. IF CHANGES IC EXISTING OR IOSSIS = RFv:SFD STRUCTURES. . ASFVVEENTS. OR kill i 15-U1 -WAY ARE IN ANY MANNL -' RL AIWA). OR WHERE THE' MIGHT OCCUR SUBSEOSENT TO OMLR APPROVAI OF T -,S APPLICATION, TI -EN A TT CHNICAI - RLVISION WILL UL WUNI I ILO IV UI'DAIL _??111Ci1 • I : RECLMMATON PLAN MAP. Drown by. BL ones Checced by P. E Christensen SCALE 1 Inch = 203 feet DATE. 02 Fevruc'y 2322 REV 5)O04: 23 November 2D22 PACE. 1 DI Water Well pawl Permit Number Istit*dt ham male Dearer I6035129 304.769I11DcsRIOSt_STATt W1RCD 10 j&%53 104 7115 73 SemSLI. ALVA I. AtE 117343-IC#1.78148 VANAA I'OWANI11 DA VARRA GARAI III 40 J4164: 104.771091 VARM C.CINIPANIES 1NC I,1: ARRA_ GARRET ) 40.339013 lota ms99 LA1ANGENCACIM 7AGGiREGATE MHOPJSTRIES 40-339401 -101.77631 S•ORW NAILMALtRESOUlnS PARTNERS t1C 4030719 104 t}kA11Ylit WAWA, ut 11011482 -301 7E1411SSSORIN NATURlu RESOURCE PARTNERS UC RAITOR SAWPAIS (LC an Oa flat tits& $sn w -.w r vs nn %tstut JCmtnrtron Date Perms[ Careion _ Wen Winttuctad*IA/11'i well Canttivcletl.y Well C onstrwrt ad Wall Gwnttucted II Canurutted Vie II Cannrrocred ; 'kraals' GeneralPu_!fote 'rnAilrw. Cone al Ear nu Itn a11nn Le nee*, PVT POW On alum 'WI, 'I 3031952 General Putout& XVI Mocth tl.. JOhsewauon Reareleallal Dental P\r Caitiff* Pilling Dr awn by ;:netted Ri Ares 3y. 3. E. 'steneen 5C LE ac M a 300 Tee DATE 22 Iebruory 2022 RE *SAN PAGE i CP 1 20 love over or 2021 h.E.k.Er.t,. 1J• d S! w,. t 1 soft 1 .r.• •N1l•F•.t1• Lent• \sa-J1.. w •••••K •.•S.. 1X.!•.1•V•YM • r.• N•3 ton ►..• • Oros. •.•a,IN• J .r • r •VA•+ 4 •a • • • se. •-•.1•-••••• is r• is a -. x> • ••••p." a:Q ••••.• • r• Se' *4 -a VS .. v: a kJ"' O✓ J a'Xl+r •• M• - ar• I. *al - Apr .1t ^. -lie roil Ls/ Yi•, •..•Jr•.• aM. NI. St 'lair• , •• J. Jolly 401 t. V•.... I VIAre, .1 •+ ' 1 .1a• we ;WO, • . WI •a;.' a •n •N ?e4'* by- • _- 4.44 • 1 •.$J••'.% tA?tpt 11 MIM$. ;it ra .AW I. •atacactt caaaac eel. R1cr.MR : W Y. an-ars• SF -11 INC; I'ONi P"-tel. Two Rivers Sand, ;ravel .?cservo r Pro:cc: DQAVANC Exhibit I/J: Sols arc Vegctatioh Mcp VOTts 234.06±Acres Basins Total 'town by 31 Jones LEGEND' ea w• • N• r 10 Checked %CALL I inch a 300 feel by p Witt 22 Pe0•./a'y 2022 Chreitensen n'."4 •" . - ._ PAZ( 1 Di ' I VV J \ VC.' b JU IUD VI UVCZI Ut ZU I\v5U' VUII t UJtJLI 734.06! Acres 3asins To:ol 7.60 Acre Wash Pond D oun by & :res 0* m arr. CCOD.CO t%,. RUes?S iw: w -w• y 127 r.-•8:116 nt 1 net . L• - J 111: 1/4 CENTRAL FIELD CENTER SECTION DR"""` Exhioit ='roricicjl Worronty Map Chet sea Dy P. Christear R[YSIOW V s ua { �_.I z• 22 Feb'uory 2022 PAC[ Hello