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Home My WebLink About20111435 EtTETRA TECH June 6, 2011 Mr. Peter S. Hays Environmental Protection Specialist Division of Reclamation, Mining and Safety 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Response to Iverson Mine(M-2011-001) Second Adequacy Review Comments Dear Mr. Hays: We received your Second Adequacy Review comments regarding the 112 Reclamation Permit Application for the Iverson Mine dated May 17, 2011. Below is a listing of each of your comments followed by our responses in italics. 16. Portions of the proposed mine site lie within the 100-year flood plain of the Cache la Poudre River. In the event of a significant flood event(100-year flood or greater) it is likely the proposed pit will be captured by the Cache La Poudre River. Wherever mining will occur within 400 feet of the river channel, a flood analysis and flood control plan must be evaluated and submitted. This would include pit side armoring, river side armoring, inflow and outflow channels, or other appropriate measures. Accordingly, the Division requests the Applicant provide the flood elevations(s)to be expected under a"worst case"flooding scenario and specific mitigation measures that will be implemented to minimize the potential for any offsite impacts. The potential for"berms" around gravel pits to be damaged during flooding is discussed in detail in the 1987 Urban Drainage and Flood Control District(UDFCD) Publication"Technical Review Guidelines for Gravel Mining Activities within or Adjacent to 100-year Floodplains." Strips of native ground or constructed fill between the stream and the gravel pit, and generally aligned with the flow direction of the stream are referred to in the UDFCD document as riverside berms. Riverside berms are proposed in the Iverson Mine application, which may be prone to erosion during a flood event. The required inflow/outflow structures are intended to mitigate possible slope failure during flood events for these berms. The Iverson Mine is outside of the political boundaries of the UDFCD, but the technical floodplain factors that led to the formation of the UDFCD guidance still apply and will be used to review the adequacy of the flood mitigation structures proposed for the site. Additionally, the site and surrounding area have a history of flooding as demonstrated by flooding event last summer which caused extensive damage to the 83rd Joint Venture mine site located east of the Iverson Mine and involved the Boyd Freeman Ditch located adjacent to the Iverson site. We discussed this comment with Tony Waldron to understand how the Urban Drainage and Flood Control District(UDFCD)Publication "Technical Review Guidelines for Gravel Mining Activities within or Adjacent to 100-year Floodplains"would apply to the Iverson Mine project which is outside of the UDFCD. Mr. Waldron explained that the DRMS would like us to analyze the Iverson Mine project in relation to the Cache la Poudre River and use the UDFCD Guidelines to propose mitigation measures that make sense for the Iverson Mine project. Therefore, Tetra Tech conducted a site visit to the Iverson property to reevaluate the impact flow of the Cache la Poudre River may have on the Iverson Mine. The meandering nature of the Cache La 1 1900 5.Sunset Street,Suite 1-8 Longmont,CO 80501 'Rp,� �% Q' D , \Q), , PL- rp LA'' Tel 303.772.5282 Fax 303.772.7039 wwwtetratech.com V1 — i3- (1 Lk- lz -t I 2011-1435 TETRA TECH Page 2 of 3 lit] Mr. Peter Hays June 6, 2011 Poudre River adjacent to this site results in erosive headcutting on one bank of the river or the other. So, using the UDFCD's Technical Review Guidelines for Gravel Mining Activities within or Adjacent to 100-year Floodplains as a guideline, Tetra Tech advised Lafarge on where erosive headcutting is on the pit side of the river. In these areas, the mine limits will be set back 200 feet from the top of bank. Where the erosion forces are predominately on the opposite bank of the river, erosion is much less of a concern and the setback will remain 100 feet from the top of bank. In addition we recommended inflow and outflow spillways be installed in conjunction with site reclamation to control the manner in which high river flows impact the site. The recommendations made by Tetra Tech are in accordance with the best practices per Urban Drainage and Flood Control District(UDFCD) guidelines and Lafarge agreed to modify the mining and reclamation plans as recommended by Tetra Tech. Attached are updated versions of Exhibits C, D, E and F(Attachments A-D) to reflect changes associated with holding a larger mining setback from the river in some areas and constructing the inflow and outflow structures at the time of reclamation. 17. Please clarify if the conveyor structure foundation at the bike path conveyor crossing will be anchored to the ground with rebar. As shown on the details for the bike path conveyor crossing, the conveyor structure foundations will be recessed into the ground which will essentially anchors the above ground conveyor bridge structure to the ground; these foundations will not need to be further anchored to the ground with rebar. 19. The Applicant did not revise the seed mix for topsoil/overburden piles listed in Exhibit C to match Exhibit E and F. Please clarify if the Applicant intended to revise the seed mix to correspond with the seed mixture for Upland Areas. The seed mix on Exhibit C(Attachment A) has been changed to match the seed mixture for upland areas as listed in Exhibits E and F. 23. Please provide the Division with a signed and notarized letter from Mr. and Mrs. Iverson stating they are aware of and accept the potential vegetation and ground water well impacts related to mine dewatering on their property. Attached please find a notarized letter from Mr. and Mrs. Iverson(Attachment E). 31. Comment from First Adequacy Review letter: The Division will estimate the cost to reclaim the site based on the information submitted once the Applicant addresses the concerns noted in this letter. In addition, the Division will include costs to comply with the Office of the State Engineers requirement for out-of-priority groundwater depletions. The reclamation plan proposes 44.1 acres of open ground water will remain after the site is reclaimed. Lafarge or the landowner must obtain a court approved augmentation plan from the Office of the State Engineer.The Division is required to set the financial warranty at a level which reflects the actual current cost of fulfilling the conditions of the Reclamation Plan per Rule 4.2.1(1). Therefore, without an augmentation plan in place the financial warranty must be set at an amount which accounts for the exposed groundwater. The Division has identified several options for determining the amount of the financial warranty. The Applicant must choose one of the following options to be included in the financial warranty calculation: a. Backfill all of the pits to two feet above the groundwater level. b. Install a slurry wall or clay liner. c. Provide the Division with documentation from SEO, which demonstrates the Applicant owns a sufficient amount of shares of water to cover the evaporative losses from the exposed groundwater and the said shares have been committed to the SEO should the financial warranty forfeited and the permit revoked. If the Applicant obtains an augmentation plan prior to final release, then the financial warranty will be adjusted accordingly. • TETRA TECH Page 3 of 3 it[ Mr: Peter Hays June 6, 2011 Comment from Second Adequacy Review letter: The Division prepared a preliminary reclamation cost estimate for the Iverson Pit. The Division estimates the total cost to reclaim the site is$233,400. The estimate is based on the Applicant choosing Option C above and will require recalculation if a different option is chosen by the Applicant. A copy of the estimate is enclosed for your review. Lafarge will probably proceed with Option C, to provide the Division with documentation from the SEO, which demonstrates the Applicant owns a sufficient amount of shares of water to cover the evaporative losses from the exposed groundwater and the said shares have been committed to the SEC should the financial warranty be forfeited and the permit revoked. We are awaiting documentation from the SEO to satisfy this documentation requirement(Attachment F). In addition, Lafarge reviewed the cost estimate prepared by the DRMS and they find it acceptable. 37. Please clarify if Lafarge is continuing to pursue signed structure agreements with TowerCo, City of Greeley and Boyd Irrigation Company or if the Applicant is relying on the engineering evaluation to demonstrate the structures will not be damaged by mining activities. Lafarge would like to rely on the engineering evaluation to demonstrate that TowerCo's, the City of Greeley's, and the Boyd Irrigation Company's structures will not be damaged by mining activities. 39. Please provide the Division with stockpile and tower surcharge loads and document the source of the surcharge loads used in the revised slope stability analysis for the communication tower so the Division can duplicate the cross section for verification. The stockpile and tower surcharge loads are 1,100 and 3,000 pounds per square foot respectively. This information has been added to the model(see Attachment F). Thank you for your consideration. Please contact me if you have any questions regarding our responses. Sincerely, TETRA TECH -.?:///el Pamela Franch Hora, AICP Senior Planner Attachments: Attachment A: Exhibit C Attachment B: Exhibit D Attachment C: Exhibit E Attachment D: Exhibit F Attachment E: Notarized letter from Mr. and Mrs. Iverson Attachment F: Stockpile and Tower Surcharge Load Information cc: Anne Johnson, Lafarge West, Inc. LARGE MAPS AVAILABLE FOR VIEWING AT THE CLERK TO THE BOARD 'S OFFICE , IN THE PUBLIC REVIEW FILE . Attachment A: Exhibit C 1_v Jsovl Y`N' u. -Pre, oa Y1l ✓ r Ran W &103 cjpg Attachment B: Exhibit D EXHIBIT D Mining Plan General This is an application for a 112 Reclamation Permit for the Iverson Mine. The Iverson Mine is located in Section 34, Township 6 North, Range 66 West of the 6th PM and includes a total of 66.5 acres. The site is north of F Street and directly south of the Cache La Poudre River. The property contains a significant commercial deposit of sand and gravel from the River. Within the 66.5 acre permit boundary, 65.9 acres of land could potentially be disturbed; the only permitted area that won't be disturbed from its current state is the access driveway into the property. Within the 65.9 acres that could potentially be disturbed, only 39.8 acres of the property will be mined. Other unmined acreage that may be disturbed will be used for overburden and topsoil stockpiles, offsets from existing structures, internal roads, and conveyors. All of the mining activities will occur on land owned by Tim and Jeanne Iverson. A strip of land owned by the City of Greeley is also included in the permit boundary and will be disturbed; it will be used for a conveyor that will carry material from the Iverson Mine to the 35 ' Avenue Mine (M-1977-036) for processing. Existing mining activities are occurring northeast of the Iverson Mine by Lafarge (35th Avenue Mine) and a quarter of a mile east by Aggregate Industries. Otherwise, riparian vegetation and agricultural uses surround the property. The site was drilled in December 2003 and again in December 2008 and testing was performed to verify the sand and gravel deposits are commercially marketable. The topsoil is approximately six to twelve inches deep and there is three to six feet of overburden across the site. Based on this, it is estimated that the topsoil will amount to approximately 40,000 cubic yards and overburden will amount to approximately 230,200 cubic yards. All overburden needed for the construction of the final reclamation slopes will remain on-site. The sand and gravel is 14'-29' deep across the site and mining at the site is intended to progress down to claystone or sandstone. It is estimated that there are approximately 1,500,000 tons of sand and gravel to be mined from the site. The groundwater level lies approximately 5 to 10 feet below natural ground level, on average. The deposit is therefore classified as a wet alluvial deposit. However, mining operations will be carried out following dewatering. As described above, the site is owned by Timothy and Jeanne Iverson and the City of Greeley. Lafarge has a lease to mine the Iverson property and a conveyor access agreement with the City of Greeley on their property. Methods of Mining The typical mining procedure will be as follows. Any areas slated for protection will be identified in the field to assure that mining operations will be set back as appropriate. When mining begins, the southeast corner of the mine cell will be stripped and the topsoil and overburden will be Iverson Mine DRMS 112 Reclamation Permit Application Page DI of D4 temporarily stockpiled outside of the floodway within the designated stockpile area on the south side of the property, as identified on Exhibit C. Once the deposit from the southeast corner has been mined, the topsoil and overburden will be stripped from the center of the cell and the material will be used to reclaim the southeast corner where possible as to not impede on the conveyor. Any material from the center that cannot be placed in the southeast corner will be placed in the topsoil and overburden stockpile area. The center of the cell will then be mined. Following mining of the center of the cell the topsoil and overburden will be stripped from the north end of the cell and the material will be used to reclaim the center of the cell. The north end of the site will then be mined. Upon completion of the mining of the north end of the cell, the area will be reclaimed using some of the overburden and topsoil stockpiled on top of the mining cell on the south side of the site. Once the north end of the cell has been partially reclaimed with the stockpiled material, the southwest corner of the site will be stripped of the topsoil and overburden and that material will be used to complete the reclamation of the north end of the cell. The southwest corner of the cell will then be mined and reclaimed with the remaining stockpiled topsoil as well as the insitu overburden. Because the site will be concurrently mined and reclaimed, Lafarge anticipates that there will be no more than 3500 linear feet of exposed slope that needs to be graded for reclamation. There will be no permanent stockpiles at this site; all extra overburden will be used to create undulating shorelines. Overburden and stockpiled topsoil will be seeded as appropriate to prevent erosion. A dewatering trench will be constructed around the perimeter of the bottom of the mining cell and sump holes will be installed. The sump holes and dewatering trenches will allow sediment to settle before the water is pumped to the Cache La Poudre River in accordance with Colorado/NPDES discharge permit regulations. When the alluvium is sufficiently dry, front-end loaders will excavate the material and deposit it on conveyors. The mining face will be nearly vertical to 0.5:1 slope. The conveyors will transport the material from the Iverson Mine, across the parcel owned by the City of Greeley to the 35`h Avenue Mine plant site for processing. No processing will occur at the Iverson Mine. All surface water within the mine areas will drain internally. A Drainage Report will be prepared for Weld County and it will provide details of the conveyance of both off-site and on-site surface water through the site. Direct precipitation falling on a mine cell is collected in the perimeter dewatering trench and pumped out. There will not be any uncontrolled releases of surface water and sediment from mining areas. Storm water collected in the open mine will be managed in accordance with Colorado/NPDES discharge permit requirements. Sediment generated from localized storm water runoff and surface drainage will be managed according to the Stormwater Management Plan, enclosed in Exhibit G (Attachment G-2). Water rights at the site will be used for dust control operations along the roads, stockpiles and berms. The water balance discussed in Exhibit G estimates the gallons per week necessary to limit dust emissions. The water will be supplied using a 2,500 gallon water truck. No explosives are planned to be used. Iverson Mine DRMS 112 Reclamation Permit Application Page D2 of D4 Topsoil and Overburden Topsoil and overburden will be stripped with scrapers or a dozer and placed in separate temporary stockpiles within the permit area limits as required by Rule 3.1.9(1). All topsoil and overburden stockpiles that are placed above the existing surface will be located outside of the floodway and, when they are in the floodplain, be oriented parallel to the flow of water. These stockpiles will be 35-40 feet tall with maximum 1.5:1 (horizontal:vertical) side slopes. Stockpiles that will be in place for more than 180 days will be seeded depending on the seeding"window" parameters for dryland grass, which are typically between September and April. The Dryland Grass Seed Mix is listed on page E3 of Exhibit E. The stockpiles will be broadcast seeded and incorporated into the weed control program. Weed control consists of monthly inspections and, if necessary, chemical treatments in the applicable fall and spring seasons. Commodities to be Mined The primary commodity to be mined will be aggregate. Lafarge will supply local, county, and state governments, as well as private industry with aggregate from this facility. Some gold may be discovered on site during the mining process. If gold is found, it will be used for commercial purposes. Offsets With the exception of a small wetland that was created by the property owner on the east edge of the mining cell, Lafarge will stay out of wildlife and riparian vegetation areas along the Cache la Poudre River. Lafarge is proposing to mine through this small created wetland area because when dewatering occurs in conjunction with the mining operation, it would be difficult to keep water in the wetland to support the wetland vegetation. Therefore, Lafarge will be working with the Corps of Engineers regarding the regulatory requirements related to the impact area. The details regarding any impacts will be worked out with the Corps of Engineers prior to the commencement of mining. In addition, a mining setback from existing structures will be maintained according to the Geotechnical Slope Analysis included in the Stability Exhibit. The highwall of the mine is set back at least 50 feet from all existing manmade structures and a minimum of 100-200 feet from the bank of the Cache la Poudre River. The meandering nature of the Cache La Poudre River adjacent to this site results in erosive headcutting on one bank of the river or the other. Where erosive headcutting is on the pit side of the river, the mine will be set back 200 feet from the bank. Where the erosion forces are predominately on the opposite bank of the river, erosion is much less of a concern and the setback will be 100 feet from the top of bank. Inflow and outflow spillways will be installed in conjunction with site reclamation to control the manner in which high river flows impact the site. Use of these spillways is in accordance with the best practices per Urban Drainage and Flood Control District(UDFCD) guidelines. When such spillways are used, the UDFCD typically permits mining to within 200 feet of the river bank. Roads and Conveyors All of the material will be transported from the mining face to the 35"' Avenue plant site for processing via conveyors. The conveyor will leave the Iverson Mine cell at the southeast corner of the Iverson property, cross the City of Greeley property on the north side of the Boyd and Freeman Ditch then turn to head north along the east property boundary of the City of Greeley property. The conveyor will cross the Poudre River Trail which is located on the City of Greeley property (per the agreement with the City of Greeley, the conveyor will be elevated at least 14'6" over the trail) and Iverson Mine DRMS 112 Reclamation Permit Application Page D3 of D4 Great Western Railway of Colorado's railroad right of way. The railroad tracks where the conveyor will cross are currently not being used by Great Western Railway of Colorado; therefore, Lafarge has an agreement with Great Western Railway of Colorado to have an at-grade crossing for the conveyor as well as for trucks. The conveyor bridge will be composed of steel; the footings are anchored in concrete. Details for the conveyor bridge can be found on Exhibit C. Upon completion of mining operations, the conveyors will be removed and all areas affected by the conveyors will be revegetated. All existing on-site roads are shown on Exhibit C, Pre-Mining Plan. Any existing gravel access roads shared with ongoing oil and gas production on the perimeter of the mining cell will remain in place once mining and reclamation are complete. The roads will be maintained by the operator to provide required access to the various activities on the property. Existing roads are typically 12' to 15' wide, gravel access lanes. If needed, roads will be relocated to accommodate mining activities. Relocated access lanes will be constructed with 6" of native sand and gravel from the floor of the mine and remain in place once mining and reclamation are complete. The main vehicular access to the site will be off of F Street. The only traffic that will use this access will be up to employees who will run the equipment. Generally there will be about four employees working on the site, but there is the potential for up to 10 employees on the site. A small parking lot area is proposed in the southeast corner of the site to accommodate employee vehicles. Mine Schedule The Iverson Mine operation will process up to approximately 600,000 tons of aggregate per year. At this rate, Lafarge anticipates mining and reclaiming the site in approximately four to five years. However, the rate of mining and overall life of the mine is dependent upon demand and market conditions. Equipment The following equipment and facilities may be utilized at the Iverson Mine site: Loaders (2) Diesel Powered Generator Set as needed (2) Dozer(2) Scrapers (2) Grader(1) Trackhoe (1) Water Truck (1) Pumps as needed (2) Conveyors and Feeders Portable Toilet(2) Fuel Station (10,000 gallon diesel fuel tank) Iverson Mine DRMS 112 Reclamation Permit Application Page D4 of D4 Attachment C: Exhibit E v EXHIBIT E Reclamation Plan Design Intent The Iverson property will be reclaimed as an unlined, open water pond surrounded by uplands. Native and adaptive plantings and ground covers will be used to restore and enhance all areas disturbed by mining activities. The most appropriate primary post-mining land use designation for the site is wildlife habitat given the fact that a majority of the property will be covered by the open water pond. However, this designation is for purposes of the DRMS application only and the property is not designated by any other agency as wildlife habitat. Therefore, following reclamation and release of the property by the DRMS, the land use of the property could be changed by the land owner according to the land use regulations of Weld County. This Iverson Mine reclamation plan was developed based on the following considerations: • A thorough evaluation of the environmental resources and existing conditions on and adjacent to the property, particularly the Cache la Poudre River riparian corridor along the west, north and east sides of the property; • The context of the property relative to existing and planned land uses in the area; • The volume, depth and configuration of the mineral resource; • The landowners' plans for the property; and • The rules and policies of the Colorado Division of Minerals and Geology and other applicable local, State and Federal agencies. • The open water pond, which will be created upon reclamation of the Iverson property, may provide some wildlife habitat due to its proximity to the river corridor. Post-Mining Land Use Following the mining of the Iverson property, the land will be reclaimed with an open water pond surrounded by upland. All areas reclaimed as upland will be re-vegetated with a native seed mix, as recommended by the Soil Conservation Service (recommended seed mixes below). This use is compatible with the surrounding land uses. Lafarge will concurrently reclaim mine walls where mining has been completed. Reclamation, including re-grading and seeding, will be completed within two to five years following the completion of mining or filling operations. The mining and reclamation will leave no high walls on the property. No acid forming or toxic materials will be used or encountered in the mining. There will be no auger holes, adits, or shafts left on the site. Topsoiling Topsoils in the proposed mine areas are Aquolls and Aquents, Ascalon loam, Dacono clay loam, Nunn loam, and Otero sandy loam. All suitable soil material will be salvaged for topsoil replacement. The topsoil will be segregated and stored separately from the overburden material as required by Rule 3.1.9(1). Upon reclamation of the site, all upland areas will be reclaimed with at least six inches of topsoil. Iverson Mine DRMS 112 Reclamation Permit Application Page El of E4 Soil amendments are not expected to be required due to the nature of the soils. However, topsoil samples will be subjected to agricultural testing prior to reclamation to assess fertilizer requirements. The Soil Conservation Services (SCS) will be contacted periodically throughout reclamation for soil tests. SCS soil fertilizer recommendations, if any, will be followed. Reclamation Measures—Material Handling Site reclamation measures are illustrated on Exhibit F. The Iverson property will be reclaimed as an open water pond surrounded by upland. The pond will be an un-sealed groundwater pond. All mine walls will be re-graded with overburden material. If needed, portions of the deposit not mined may be used to supplement the overburden. Slopes both above and below the post-mine high water level will all be 3H:1 V or flatter. Topsoil will be spread over the surface of the re-graded slopes in all areas above the post-mining pond level; all topsoil-covered surfaces will be revegetated with the appropriate seed mix. Topsoil replaced in upland areas will be at a depth of at least six inches. Scrapers and a dozer will be used to place the backfilled overburden and topsoil. Using the scrapers and dozer to layer the lifts at a maximum 3H:1 V slope ensures a stable configuration. Site grading will be performed to create stable topography and will be consistent with post-closure land uses. Reclamation costs and quantities are summarized in Exhibit L. Water Overburden and mine materials will be inert and impacts to local surface water or groundwater quality are not anticipated to occur as a result of mining activities. Lafarge West, Inc. will comply with all applicable Colorado water laws and all applicable Federal and State water quality laws and regulations and appropriate storm water management and erosion control to protect the river and existing riparian vegetation. Wildlife The Iverson property is adjacent to the Cache la Poudre River corridor which provides wildlife habitat to a variety of species (see Exhibit H for details). All mining will be setback 100-200 feet from the bank of the river to be outside of the riparian corridor to minimize any potential impacts on wildlife within the riparian corridor. Revegetation Following topsoil replacement, reseeding will be performed according to SCS recommended practices. Based on SCS guidance for other local projects having similar surficial soils, the following revegetation procedures are anticipated: • Grass seed will typically be planted in unfrozen soil between October 1 and April 30. • Grass seed will be planted with a grass drill, or where necessary, with a broadcast seeder. • The proposed seed mix and application rates in pounds of pure live seed per acre are described on the following pages. • Weed control practices will be implemented as required. Iverson Mine DRMS 112 Reclamation Permit Application Page E2 of E4 The above procedures may be modified as conditions dictate. Russian Olives existing prior to mining will not be removed by Lafarge. If a significant invasion of noxious weeds occurs, the area will be mowed periodically for control. Weeds will be mowed before they go to seed during the first growing season. Mechanical control will be used as a first priority. Chemical methods will be used only if no other alternative produces acceptable results. Marsh and aquatic plants are expected to establish themselves along the shoreline of the post- mining pond. The species of plants anticipated to establish themselves naturally along the pond shoreline include cattails, willows, cottonwoods, and bulrushes. The existing riparian areas along the Cache la Poudre River would function as a seed bank for the pond area. These plants should minimize shore erosion potential. The following are the proposed seed mixtures to be used on site where appropriate. However, availability may dictate the need for variety substitution. Seed Mix for Upland Areas °la bf PLS Common Name Scientific Name Variety Mix Application Rate lbs/ac Western Wheatgrass Agropyron smithii Arriba 17.0% 2.55 Sideoats Grama Bouteloua curtipendia Butte 17.5% 2.63 Mountain Brome Bromus marginatus Bromar 17.0 % 2.55 Prairie Sandreed Calamovilfa longifolia Goshen 1.0% .15 Switchgrass Panicum virgatum Pathfinder 7.0% 1.05 Alkali Sacaton Sporobolus airoides 1.0% .15 Needle and Thread Stipa comata 13.0% 1.95 Northern Sweetvetch Hedysarum boreale Timp. 10.0% 1.50 Rocky Mountain Penstemon Penstemon strictus Bandera 5.0% .75 Scarlet Globemallow Sphaeralcea coccinea ARS2936 3.0% .45 Prairie Wildrose Rosa Arkansana 8.5% 1.28 Total lbs/ac 100% 15.01 Pure Live Seed pounds per acre; rates shown are for drill seeding; double rates for broadcast seeding. Iverson Mine DRMS 112 Reclamation Permit Application Page E3 of E4 Seed Mix for Transitional Zone/Water's Edge of PLS Common Name Scientific Name it `_ Variety; Mix Application. Rate'!(tbs/ac) Western Wheatgrass Agropyron smithii Arriba 10.6% 1.59 Side Oats Grama Bouteloua curtipendia Butte 9.2% 1.38 Canada wildrye Elymus canadensis Mandan 18.1% 2.72 Streambank Wheatgrass Elymus lanceolatus ssp. Sodar 9.8% 1.47 psammophilus Switchgrass Panicum virgatum Pathfinder 5.7% .86 Sand dropseed Sporobolus cryptandrus 0.2% 0.03 Scarlet Globemallow Sphaeralcea coccinea ARS2936 3.8% 0.57 American vetch Vica americana 42.6% 6.39 Total lbs/ac 100% 15.01 Pure Live Seed pounds per acre; rates shown are for drill seeding; double rates for broadcast seeding. Iverson Mine DRMS 112 Reclamation Permit Application Page E4 of E4 Attachment D: Exhibit F Zverfon rni Zh ecva v\ _m PkUvA a pp Attachment E: Notarized letter from Mr. and Mrs. Iverson May 23, 2011 Ms.Anne Best Johnson,AICP Lafarge West, Inc. 11409 Business Park Circle, Suite 200 Longmont, CO 80504 RE: Acknowledgement and Acceptance of Potential Impacts on Existing Iverson Property Groundwater Wells and Vegetation Dear Ms. Johnson: We understand and accept the fact that Lafarge will need to dewater as part of the mining activity on our property located at 5011 F Street, Greeley, Colorado 80631 and that groundwater levels may be impacted. We acknowledge and accept the fact that the effect on groundwater levels could stress the existing vegetation on our property and cause it to die. In addition, we understand that we may experience drawdown in our groundwater wells and that Lafarge will follow the attached Iverson Mine Groundwater Monitoring and Mitigation Plan if this occurs. Sincerely, Tim D. Iverson JJ nne Iverson Attachment Notary Certificate: State of Colorado )ss. County of Weld -Vol The foregoing instrument was acknowledged before me this '-J day of , 2011, by Tim D. and Jeanne Iverson. My Commission Expires: 7-13-a O/ ,cis) £1Ls- Lns-A-) Pod, 4te• Notary PubliclisSal t sHM" i el F"SDP COO Attachment F: Stockpile and Tower Surcharge Load Information o 1 O c) 4- > o CO a CD a C Q ,� m Q c co co N a3 co o r 00 a3 r a D r O D r aI ' • L •_ c13 -c c O 0 _ cn _ O cu > 41 U '(I o ° W 'ai o ° O .0- o ° it '� o ° a) > al Ni Q) > en Q) o Q) N r E �- .c - E .c .- E .c .- Ems _ .— .a) c o c cu c of as c o n a) c o I z D O Cl_ Z D O a. Z D O D. Z D O a 0 CD `. - _. . a / I f) / a col 0 00 •• / `n r_ / r / o } ' / J } } / O x / 0 a) % { fir:° 4 coI :. w4.�' ` ':'• ' U D u CO a o u CO II a 4- U a 0 C N C u. M 4. r + s S 4-• 4 # u ,a? o 4- cc U a O C a L. cDW CO c 0 3 a -I—. a 4oso -- O 0. a 3 Ilir t iEjJ 0 H D a, i c Cl) E i a I V O U 0 + Cl) :It' - ' a RS 0 c .- I a .� = a - I a a E - .W O o C CO 5 U) U + i C C I I c • C I r La r O >• V ' 0 if � cy c\ — a) i ' in a) — ; O ca r ra tiFi 4 I I o Lc a �L. AL LC ,J U LO In 0 in 0 In o LO o �n o �n 0 �n o Q 0) Cn CO CO I` N- (.0 (.0 �n Ln d- CO CO N N CD CD CO CO CO Co CD Co CD CO CO CO CO Co CD CD ( 000 [- x) (4) uo!JGnes EMITETRA TECH June 6, 2011 Weld County Clerk to the Board of County Commissioners 915 10th Street Greeley, CO 80631 RE: Iverson Mine, Response to DRMS 2n°Adequacy Review Letter Dear Clerk: Attached please find a copy of documentation to be submitted to the DRMS regarding 112 Reclamation Permit M-2011-001 regarding the Iverson Mine in Weld County,Colorado. As required by Section 1.6.2 (1)(c) of the Colorado MLRB Rules, a copy of this documentation must be made available to the public through the County in which the project is located. Therefore, please file these documents with the copy of the Iverson Mine Application that we delivered to your office on January 3, 2011. As proof that you have received this documentation, please sign and time and date stamp below. Thank you for your assistance. Sincerely, TETRA TECH Ylin%/u:Fk u fZ ; J Pamela Franch Hora,AICP Senior Planner Attachment This is to certify that the above referenced documentation for the Iverson Mine DRMS application was received by the Weld County Clerk to the Board of County Commissioners to be kept on file for public viewing. Certification: The above mentioned document was received by: Weld Coun Jerk to the Board oh County Commissioners Time and Date Stamp Here: P:\23511\133-23511-10002\ProjMgmtWorrespondence\Weld County\Record of Filing 6611.doc t.2 Tel Fax TETRA TECH I r_D h: t r June 8, 2011 Mr. Peter S. Hays Environmental Protection Specialist Division of Reclamation, Mining and Safety 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Response to Iverson Mine(M-2011-001)Second Adequacy Review Comment#31 Dear Mr. Hays: Below is the Iverson Mine Second Adequacy Review Comment#31 followed by Lafarge's response to the comment. 31. The Division will estimate the cost to reclaim the site based on the information submitted once the Applicant addresses the concerns noted in this letter. In addition,the Division will include costs to comply with the Office of the State Engineers requirement for out-of-priority groundwater depletions. The reclamation plan proposes 44.1 acres of open ground water will remain after the site is reclaimed. Lafarge or the landowner must obtain a court approved augmentation plan from the Office of the State Engineer.The Division is required to set the financial warranty at a level which reflects the actual current cost of fulfilling the conditions of the Reclamation Plan per Rule 4.2.1(1). Therefore,without an augmentation plan in place the financial warranty must be set at an amount which accounts for the exposed groundwater. The Division has identified several options for determining the amount of the financial warranty. The Applicant must choose one of the following options to be included in the financial warranty calculation: a. Backfill all of the pits to two feet above the groundwater level. b. Install a slurry wall or clay liner. c. Provide the Division with documentation from SEO,which demonstrates the Applicant owns a sufficient amount of shares of water to cover the evaporative losses from the exposed groundwater and the said shares have been committed to the SEO should the financial warranty forfeited and the permit revoked. If the Applicant obtains an augmentation plan prior to final release, then the financial warranty will be adjusted accordingly. Comment from Second Adequacy Review letter: The Division prepared a preliminary reclamation cost estimate for the Iverson Pit. The Division estimates the total cost to reclaim the site is$233,400. The estimate Is based on the Applicant choosing Option C above and will require recalculation if a different option is chosen by the Applicant. A copy of the estimate is enclosed for your review. Lafarge has chosen to go with Option C. Attached please find a letter from the SEO to fulfill the documentation requirement. Tel Fv. �1u ataVQ-) em3 Cl/. Pt_ , c) 1Q- 15-II © TETRA TECH Page 2 of 2 Mr.Peter Hays June 8, 2011 With this letter, all Adequacy Review comments for Iverson Mine(M-2011-001)have now been addressed. Thank you for your consideration. Sincerely, TETRA TECH AL-71PPamela Franch Hora,AICP Senior Planner Attachment:Letter from Office of the State Engineer cc: Anne Johnson, Lafarge West, Inc. 4Oe• . • DEPARTMENT OF NATURAL RESOURCES DIVISION OF WATER RESOURCES �8�6 ** John W.ffickerdooper Mike June 8, 2011 ' Director Dick• �tattee& Mr. Corey Hansen Lafarge North America, Inc. 10170 Church Ranch Way Suite#200 Westminster, CO 80021 RE: Lafarge West Inc. Iverson Mine(M-2011.001) Section 34,Township 6 North, Range 66 West, 6"'P.M. Water Division 1,Water District 2,Weld County Dear Mr. Hansen: This letter is in response to the letter dated May 16, 2011 from Jared Damns at Applegate Group, Inc. requesting confirmation of the adequacy of the share dedication for the proposed Iverson Mine. According to the letter, during mining operations the site will be dewatered to allow dry mining, so groundwater exposure during the life of the mining operation is expected to be minimal. However, at the conclusion of mining, the proposed reclamation plan anticipates that an unlined pond of approximately 44.4 acres in size will remain on site. The estimated net evaporation from exposed water In the area of the proposed mining operation is 2.92 acre- feet/acre per year based on a gross evaporation of 45 inches and average historical precipitation of 14.2 inches, based on information obtained from the nearby Greeley UNC climate station. Therefore, the total annual depletion that would result from the 44.4 acres of exposed ground water is 129.72 acre-feet per year. In accordance with the letter dated April 30, 2010 from the Colorado Division of Reclamation, Mining, and Safety("DRMS"), all sand and gravel mining operators must comply with the requirements of the Colorado Reclamation Act and the Mineral Rules and Regulations for the protection of water resources. The April 30, 2010 letter from DRMS requires that you provide information to DRMS to demonstrate you can replace long term injurious stream depletions that result from mining related exposure of ground water. The DRMS letter identifies four approaches to satisfy this requirement. In accordance with approach no. 4, you have provided a affidavit from Tim Iverson dated May 12, 2011 that dedicates 6.25 shares of the Greeley Irrigation Company ("GIG")to the augmentation of the sand and gravel operation assigned DRMS permit no. M-2011-001 and the future Substitute Water Supply Plan for as long as there are depletions at the associated gravel pits or until such time as another replacement source is obtained. In addition, the affidavit states that the shares will not be sold, leased, or traded to others during the term of this dedication. A copy of the affidavit is attached to this letter. This affidavit is acceptable for the dedication of the shares; however, if the State Engineer determines that a different affidavit or dedication process is necessary to assure proper dedication of the shares, additional information may be required as part of the Substitute Water Supply Plan ("SWSP")approval process. Office of the State Engineer 1313 Sherman Street,Suite 818•Denver,CO 80203•Phone:303-866-3581 •Fax:303-866-3589 www.water.state.co.us Mr. Corey Hansen June 8, 2011 Page 2 The GIC owns a sit interest in the water rights decreed to the Greeley Canal No. 3 and 60 preferred rights in Fossil Creek Reservoir. A portion of the Greeley Canal No.3 was changed in Division 1 Water Court in case no. 96CW658 based on a ditch-wide analysis by the Poudre Prairie Mutual Reservoir and Irrigation Company. The decree in case no. 1996CW658 found that 519.7 shares were used to irrigate 3,501 acres with an average historic consumptive use of 5,358 acre-feet per year,which yields an average consumptive use credit of 10.31 acre-feet per share (5,358 acre-feet/519.7 shares)or an average consumptive use credit of 1.53 acre-feet per acre. The 6.25 shares of GIC are expected to yield a consumptive use amount of 64.4 acre-feet per year(10.31x6.2534.4 acre-feet). Based on the consumptive use amounts determined in case no. 96CW658 Mr. Iverson's 6.25 GIC shares would be adequate to replace depletions from approximately 22.1 acres of exposed water surface. Since the dedicated shares are not adequate to replace depletions from all ground water projected to be exposed as part of final reclamation, the Applicant must not exceed 22.1 acres of exposed water surface, until such time as additional water is dedicated or adequate bonding is obtained. For purposes of this letter the 22.1 acres would be the surface area of the exposed ground water that would result if dewatering ceased and the ponds were allowed to fill. Prior to any exposure of ground water at the site, or consumption of ground water for any purpose, the Applicant must obtain a SWSP and well permit. The dedication of the shares as referenced herein will be incorporated into the SWSP approval along with the requirement that no more than 22.1 acres of ground water be exposed until such time as additional water is dedicated to the plan or adequate bonding is obtained to assure that that all permanent depletions from either an unforeseen abandonment of the site by the Applicant or as a result of long term ground water exposure after completion of mining and reclamation will be replaced so as to prevent injury to other water rights. Please contact Joanna Williams at (303) 866-3581 ext. 8265, if you have any questions concerning this letter. Sincerely, tz�� a "'L Joa a Williams P.E. r Resource Engineer Attachment: Affidavit from Tim Iverson regarding dedication of the 6.25 GIC shares GIC stock certificate cc: Peter Hayes, Division of Reclamation Mining and Safety Jonathan Hemandez, Division 1 • Dedication of Water Rights to Lafarge West Inc.'s Iverson Sand &Gravel Pit M-2011-001 I, Tim Iverson •as the owner of 6.25 Greely irrigation Company shares,hereby affirm that 6.25 shares will be dedicated to the augmentation of the sand and gravel operation assigned DRMS permit number M-2011-001 and the future Substitute Water Supply Plan for as long as there are depletions at the associated gravel pits or until such time as another replacement source is obtained. The 6.25 shares will not be sold,leased,or traded to others during the term of this dedication. Tim Iverson Date: S• (Z . 20 STATE OF COLORADO ) COUNTY OF W€,I ) I , The foregoing instrument was acknowledged before me this /1'''day of , 2010,by Tina Tut-es-64-1ant and • My commission expires: 3-If- -1°17* Witness my hand and official seal. tpRY ****c lir �(�c Mtn° I 'S i DAM i E Notary Public -'i'; N° 3066 INCORPORATED JULY 15,1882 SHARES--6-1/4--- • The Greeley Irrigation Company Capital Stook$13,126.00 628 Shares of the par value of$26 each •, -''.• ) This certifies that The Public Trustee of Weld County for the use of • Norwest Bank Greeley, National Association, Beneficiary of First Deed of Trust; and Tim D. Iverson and Jeanne Iverson, Joint Tenants, Equitvli;the owner of ---6'1/4-- ' Shares of the Capital Stock of ' Owners •':; .. THE GREELEY IRRIGATION COMPANY transferable only on the books of the Corporation by the holder hereof, or by .i Attorney, upon surrender of this Certificate properly endorsed. "- IN WITNESS WHEREOF,.the said Corporation has caused this Certificate to be signed by Its duly authorized officers and to be sealed with the seal of the Corporation, at Greeley, Colorado, this 31st day of March A.D. 1 A 94 J CORPORATE SEAL c •i jo-y._.,..,,_ ..a C_clnep.,+ C—_ / err. 3� eeo (( mrury reeeovrr • ' Iv • i © TETRA TECH June 8,2011 Weld County Via Email Clerk to the Board of County Commissioners 91510'Street Greeley,CO 80631 RE: Iverson Mine,Response to DRMS 2n°Adequacy Review Comment#31 Dear Clerk: Attached please find a copy of documentation to be submitted to the DRMS regarding 112 Reclamation Permit M-2011-001 regarding the Iverson Mine in Weld County,Colorado. As required by Section 1.6.2 (1)(c)of the Colorado MLRB Rules,a copy of this documentation must be made available to the public through the County in which the project is located. Therefore, please file these documents with the copy of the Iverson Mine Application that we delivered to your office on January 3, 2011. As proof that you have received this documentation,please sign and time and date stamp below. Thank you for your assistance. Sincerely, TETRA TECH �,/� r� �� di Pamela Franch Flora,AICP Senior Planner Attachment This is to certify that the above referenced documentation for the Iverson Mine DRMS application was received by the Weld County Clerk to the Board of County Commissioners to be kept on file for public viewing. Certification: The above mentioned document was received by: Weld County Clerk to the Board of missloners G Time and Date Stamp Here: , p\23511\133.2331110002\hyM{mt\Conupooderoa\Vhtl CnMyylxord of MN 6811 doc Tel Fax Hello