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Home My WebLink About20222293.tiffWindsor East DRMS RECEIVED APR as 2023 WEt.D COUNTY COMMISSIONERS Regular 112 Operation Reclamation Permit Application to the Colorado Division of Reclamation, Mining, and Safety April 2023 revisions APPLICANT: Martin Marietta Martin Marietta Materials, Inc 1800 North Taft Hill Road Fort Collins, Colorado 80524 REPRESENTED BY: TETRA TECH 351 Coffman Street, Suite 200 Longmont, CO 80501 (303) 772-5282 PvbI:C Rev:evJ 0.4M/23 cc : PL(TP/m.05A /Ko/aA), PW @H/ER/CK/DN/DD) 04h-7/23 2022 -2.2.9 3 EiTETRA TECH April 3, 2023 Peter Hays Division of Reclamation, Mining and Safety 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Response to 2nd Adequacy Review Comments for Martin Marietta Materials, Inc., Windsor East Mine, File No. M-2022-042, 112c Permit Application Dear Mr. Hays: This letter is in response to your 2nd Adequacy Review Letter, dated March 22, 2023, regarding Exhibit G - Water Information for Martin Marietta Windsor East Mine's 112c Permit Application (File No. M-2022-042). Please find below our responses to the comments made by Eric Scott in his letter dated March 17, 2023. For ease of review, we are only responding to the comments made by Eric where he had more to say than "Adequate as Submitted". Comments 4. Section 1.6 of the provided materials describes a "simplified model" and states that it was calibrated/verified based on observed drawdown in one well. This model is then used to predict groundwater drawdowns due to mining after one year and 5 years of dewatering at distances up to 2640 feet. DRMS will require a substantially more rigorous modelling demonstration to predict and illustrate the maximum groundwater drawdown impacts from dewatering during mining, potential impacts to nearby wells, as well as any post -mining mounding and shadowing impacts due to the construction of impermeable or low permeability mine cells. The model should provide GW drawdown/mounding contour maps based on, and verified against all available site setting and geologic information, current and historic water level data, and the predicted size and location of mining cells (for both sites). Additional modeling was not provided, however, the rationale for not providing a modeling evaluation based on: existing monitoring and drawdown data, distance and direction to nearest non -monitoring wells, and nearest well ownership and use is sound. In addition, although the likelihood of impacts to off -site wells is minimal, the monitoring and mitigation plans provided should be able to sufficiently address any unforeseen impacts if any are observed. Response Acknowledged 5. Section 2.1 of the provided exhibit states that up to 5 quarters of "baseline" GW level data will be collected for the WEM site with the exception of Cell A where dewatering will commence immediately. This is based on the rationale that GW levels in that area have already been impacted by the adjacent Parsons dewatering activity. DRMS acknowledges that the historic GW regime has likely already been impacted to some extent by the adjacent Parsons site. However, based on the observations of significant GW drawdowns at distance from the Parsons site, allowing dewatering of Cell A while attempting to collect "baseline" water level data for the remainder of the WEM site will likely render that data useless as a "baseline" for later mining drawdown comparison. Dewatering or exposure of GW should not be allowed on the WEM site until the full 5 quarters of baseline data can be collected. a. Mining below groundwater/dewatering of Cell A during collection of the 5 quarters of baseline data may also adversely impact the validity of the baseline analytical data results. TETRA TECH page 1 of 3 DRMS Adequacy Review 2 Response, Exhibit G April 3, 2023 Not addressed, however, rationale provided for the proposed activity based on existing data and continued monitoring is sound. Response Acknowledged 6. Water Quality Parameters and rationale presented in section 2.2.1 and Table 5 are acceptable as presented with the following edits. a. Add CN to section 2.2.1 or sample for it. b. WQS for U should be 0.0168 to 0.03, not 0.02 as stated in Table 5 c. Will any QA/QC samples be collected/run to verify field and lab procedures? d. I note that although there are several wells on the adjacent Parsons site, no analytical data has been presented as "background" for WEM, however, that may be a subject for another discussion. Adequate as submitted - with the exception of item "c." No response was provided to address the question if any QA/QC samples would be collected/run to verify field and lab procedures as a component of the provided analytical monitoring plan. If no QA/QC samples are collected the applicant will need to acknowledge that the only way to address potential "outlier" data, if observed, will be through re -sampling and re -analysis. Response Martin Marietta will collect a duplicate sample as part of each sample -collection round to improve QA/QC for the program. Exhibit G has been revised to reflect this. 10. Section 2.3 also states that "if a well goes dry, MM will implement mitigation measures within 7 days." In the event that a well owner reports that their well has become unusable, MM will be required to implement mitigation measures immediately (as soon as practically possible). MM will concurrently commence an investigation into the status of the complaint. The results of this investigation as well as any proposed remediation or rationale for discontinuing mitigation will be submitted to DRMS for approval within 30 days. Partly addressed. The language in comment #9 above has been incorporated. The initial investigation, as well as the temporary, and long-term impact mitigation measures proposed are reasonable and appropriate. However, the operator should acknowledge that the DRMS, and potentially the MLRB, are responsible for determining if mitigation is required, as well as when and how any mitigation measures are implemented and discontinued after the initial complaint is received. Response Exhibit G language in section 2.3 has been revised to explicitly recognize that the DRMS and/or MLRB are responsible for determining if mitigation is required and when and how mitigation measures will be implemented following receipt of a complaint. 11. Appendix G-3: Because the analyte list and reporting levels have been identified, please identify and include the sample container type and size, preservative (if required), holding times, and analytical method to be used. This information could also be included in Table 5. Adequate as submitted - Analytical methods have not been provided, but it has been noted on Table 5 that the method selected must provide reporting levels below the applicable standards. Response Acknowledged. TETRA TECH page 2 of 3 DRMS Adequacy Review 2 Response, Exhibit G April 3, 2023 Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH P.G. Christop (Arizona) Hydrogeologist cc: Julie Mikulas, Martin Marietta Pam Hora, Tetra Tech er Gutmann, 0: \Projects1Longmont18741 X117-8741006Wocs\ DRMSVAdequacy Review 2 Responses\2023 04 Adequacy Response 2 DBMS. docx TETRA TECH page 3 of 3 Windsor East Mine, Exhibit G — Water Information April 3, 2023 EXHIBIT G: WATER INFORMATION 1.0 INTRODUCTION AND BACKGROUND This Exhibit addresses the hydrologic conditions at the Windsor East Mine located in Section 36, Township 6 North, Range 67 West of the 6th Principal Meridian, Town of Windsor, Colorado (See Figure G-1), The Exhibit documents the depth and direction of groundwater flow, the nature of the subsurface geologic materials through which it flows (Figure G-2), any interactions with streams, lakes, canals or other surface water bodies in the area and the potential impacts to surrounding water users due to mining impacts. The information in this Section is intended to satisfy the requirements outlined in Sections 3.1.6, 6.3.3, 6.3.4, and 6.4.7 of the Colorado Mined Land Reclamation Board's Construction Material Rules and Regulations. Section 3.1.6 (1) Hydrology and Water Quality: 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, including, but not limited to: (a) compliance with applicable Colorado water laws and regulations governing injury to existing water rights; (b) compliance with applicable federal and Colorado water quality laws and regulations, including statewide water quality standards and site -specific classifications and standards adopted by the Water Quality Control Commission; (c) compliance with applicable federal and Colorado dredge and fill requirements; and (d) removing temporary or large siltation structures from drainage ways after disturbed areas are revegetated and stabilized, if required by the Reclamation Plan. Section 6.4.7 (1) If the operation is not expected to directly affect surface or groundwater systems, a statement of that expectation shall be submitted. This site is directly adjacent to the Cache la Poudre River. The Cache la Poudre River will be utilized for the discharge of dewatering water from each of the proposed mine cells. The presence of the river has the collateral benefit of mitigating groundwater drawdowns and associated impacts to wells east of the Site. (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 maybe affected by the proposed mining operations. Please see Exhibit C Pre -Mining Maps for the location of all 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 DTETRA TECH Page 1i1i Windsor East Mine, Exhibit G — Water Information April 3, 2023 The Windsor East site is underlain by two aquifers: The valley -fill deposits of the Lower Cache Ia Poudre River. o described in: Hershey, L.A. and PA. Schneider, 1972. "Geologic Map of the Lower Cache la Poudre River Basin, North-Central Colorado", USGS Miscellaneous Geologic Investigations Map 1-687. (See Figure G-2) The Fox Hills Sandstone o described in: Robson, S.G. 1989, "Alluvial and Bedrock Aquifers of the Denver basin — Eastern Colorado's Dual Ground -Water Resource", USGS Water -Supply Paper 2302 (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. The geologic conceptual model of the subsurface and groundwater was developed from the geologic map for the area and the boring logs associated with the installation of the monitoring well network at the Windsor East site and the Parsons Mine site located to the east (Figure G-3). Based on water levels measured in these wells, a groundwater level elevation map was developed (Figure G-5). Following removal and stockpiling of topsoil, each of the four cells will be dewatered and mined. Sand and gravel will be extracted using the "dry" mining method in which the water table is lowered to allow mining to be performed under drained conditions. To lower the water table, local dewatering is conducted using a perimeter drain constructed around each planned mining cell. The dewatering system would discharge to the Cache Ia Poudre River. Dewatering of the mine would lower the groundwater levels to a limited extent in the surrounding alluvial aquifer and will not impact the underlying Fox Hills Sandstone aquifer. Effects on groundwater levels are projected to be limited in extent due to natural and manmade hydrologic and hydrogeologic characteristics and boundaries, principally including the transmissive nature of the alluvial aquifer, the Cache Ia Poudre River, and the mining operation. Figure G-6 illustrates the resulting changes to groundwater flow directions during mining and after reclamation. The available gravel resource is anticipated to be mined for approximately 6 years; however, the rate of mining and overall life of the mine is dependent upon demand and market conditions. All material mined at Windsor East will be conveyed to Martin Marietta's adjacent Parsons Mine site for processing at the existing plant on that site. Upon completion of mining, the reclamation plan for the mine includes the placement of compacted clay embankment liners in Mining cells A and C, while cells B and D will be backfilled with non -economic grade alluvium including topsoil, sands, and fine gravel. These cells will thereby be converted to sealed water storage reservoirs, which will be owned and used by GWIP, LLC, the landowner of the Windsor East Mine site. Exhibit D: Pre -Mining and Mining Plan shows the location of the Affected Area and proposed mining cells. Changes to the hydrologic balance within the Affected Area will be limited to the localized dewatering associated with the excavation of the mine cells, and the minor alteration of the existing groundwater flow patterns due to the subsequent installation of compacted clay embankment liners during reclamation. Figures G-5 and G-6 show the mine cells and conceptual groundwater flows before and after the installation of the compacted clay liners. 1.1 HISTORIC USE The Windsor East property has historically been used for agriculture. The adjacent neighbors include Martin Marietta's Parsons Mine site to the east, agricultural land with a few residences to the north and west, and the Cache Ia Poudre River to the south. Based on well registration, land use besides agriculture within two miles of the site has included Eastman Kodak to the west and northwest, Front Range Energy to the northwest of the site, Joseph Energy to the northwest of the site, and Hensel Phelps Construction to the northwest of the site. aTETRA TECH Page 2111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 1.2 HYDROGEOLOGIC SETTING 1.2.1 Geology The geology mapped at land surface beneath the site consists of quatemary age valley -fill deposits comprised of sand, silt and gravel primarily (Figure G-2). The areas of higher elevation around the site are typically comprised of quaternary terrace deposits. Boring logs from installation of monitoring wells immediately east of the property were reviewed for details on the site geology. The Parsons sand and gravel mine has 12 monitoring wells on the property, including MW -12 which is the nearest to the Windsor East property, located between the Parsons property and the Windsor East property (Figure G-3). The boring logs generally indicate that the geology consists of a 10-30 ft thick layer of unconsolidated alluvial sediments overlying siltstone bedrock. The upper 4-14 feet of the alluvial sediments are typically finer -grained silts and clays and may be only partially saturated in many locations. The lower 4-20 feet of the alluvium consists of sands and gravels which are expected to be highly transmissive of shallow groundwater. The shallow bedrock of the Fox Hills Sandstone consists of weathered, consolidated sedimentary rock varying from claystone to siltstone as observed in the boreholes advanced on the Parsons mine property to the east. In comparison to the alluvium, the weathered bedrock is expected to be several orders of magnitude less transmissive due to the consolidated, finer -grained properties. Bedrock was encountered in the boreholes advanced at the Windsor East mine property between 15 and 22 ft below ground surface (bgs), and 13ft bgs in the nearest Parsons Mine borehole (Parson MW -12). 1.2.2 Groundwater Groundwater at the site represents a combination of water that flows through the high -permeability valley -fill alluvial deposits parallel to the Cache la Poudre River and water that infiltrates in the surrounding higher -elevation recharge areas to the north and south of the river, typically associated with the agricultural fields that dominate the land use of the area. Infiltrating water in these areas of higher elevation drains at the lower -lying erosional valleys formed by streams and rivers of the area, resulting in flow patterns that resemble a muted form of the land surface topography. The erosional valleys are typically underlain by the higher -permeability sands and gravels deposited by historic flood events and form channeled zones through which groundwater can flow more rapidly. South of the Windsor East property, the Cache la Poudre River is the surface -water feature for local groundwater discharge. Within several hundred feet of the river, groundwater flows in a direction that is near parallel to the river due to the constant interaction with the river stage within the porous sands and gravels. As a result, while groundwater beneath the site is typically slightly higher than that of the river and flows toward the river, the flow direction of groundwater flow is generally parallel to the Cache la Poudre River from west to east, at close proximity (Figure G-5). Some minor component of upward groundwater flow from the deeper bedrock may occur, but this is likely to be negligible compared to the influence of the river and the underflow within the valley -fill alluvium. The direction of regional shallow groundwater flow is therefore toward the southeast but changing to a near easterly direction near the river. Based on water -level measurements in the monitoring wells installed at the Windsor East mine property, the water table is approximately 8-11 feet below land surface. 1.3 EXISTING AND PLANNED WELLS 1.3.1 Existing Monitoring Wells A network of monitoring wells was installed in 2010 to characterize the groundwater conditions at the Parsons mine east of the Windsor East property (Figure G-3). The boreholes for the wells were drilled to the bedrock contact and the wells were constructed using 8-10 foot screened intervals between the water table and the bedrock contact. These wells generally show the direction of groundwater flow in an easterly direction, in equilibrium with the river water elevations, although subject to the influence of the Parsons mine cell dewatering. QTETRA TECH Page 3111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 1.3.2 Well Inventory In May 2022, a well inventory of the Affected Area and adjacent areas was conducted to identify wells near the project. The inventory included a search of the State of Colorado Office of the State Engineer database of wells located within 1 mile of the Affected Area (Table 1). The well inventory identified 25 constructed wells within IA mile of the Affected Area. Figure G-4 enclosed shows the Affected Area and the constructed well locations on file with the Colorado Division of Water Resources. Wells located within 600 feet of the Lease Boundary The well inventory identified two wells completed in the alluvial aquifer within 600 feet of the lease -area boundary. The first is a monitoring well (Parsons MW -12) owned by Martin Marietta (permit # 280593) associated with the Parsons mine immediately to the east of the Windsor East property. Bedrock was encountered at 13 ft bgs and water was observed at approximately 6-8 ft bgs. The second is a monitoring well owned by Hall -Irwin Corporation (permit # 277000). It was constructed in 2007 and was screened from 4 to 15 ft bgs. Bedrock was encountered at 13 ft bgs and water was observed at approximately 2 ft bgs in 2007. Monitoring holes and wells are not a concern for dewatering impacts because neither are allowed to serve as pumped sources of water. Water supply wells located within % mile of the Lease Boundary In addition to the wells identified within 600 feet of the lease boundary, the well inventory identified two residential wells, eight monitoring/observation wells, three monitoring holes, and one general purpose well completed in the alluvial aquifer within 1 mile of the lease -area boundary. Appendix G-5 provides a letter from GWIP LLC regarding the status of wells 89706-A, 113762—A, and 1472 -R -R. Permit number 89706-A Domestic/Residential well (89706-A) is registered to Brett T and Mary K Lauer. It was constructed in 1977 to a depth of 32 feet. It is located slightly more than 600 feet distance from the lease boundary on the northwest corner, and approximately 1,060 feet northwest from the nearest planned mining cell. The well is 5 -inch diameter PVC, screened from 17 to 32 ft bgs, and was equipped with a pump capable of 30 gpm. The driller's log indicates that water was encountered at 12 feet bgs in 1977. A 6 -hr pumping test conducted in 1977 resulted in sustained pumping of 20 gpm and a pumping water level of 27 ft bgs (15 feet of drawdown, a specific capacity of 1.33 gpm/ft). Bedrock was observed at 27 ft bgs. The parcel that this well sits on is owned by GWIP LLC, the property owner for this reclamation permit application. Permit number 113762--A Domestic well (113762--A) is registered to M WaterCo LLC, although originally to Harold Long and Sons. It was constructed in 1980 to a depth of 25 feet. Water was noted at 12 ft bgs and bedrock was encountered at 20 ft bgs. A sustained pumping test of 30 gpm for 2 hours was conducted in 1980 with no recorded drawdown. It is located 1500 to 2000 feet distance from the lease boundary on the north side. A registered domestic well with a similar permit number (113762-) is associated with Harold Long and Sons Inc. The date of construction was not recorded, but the well inventory indicates that it was drilled to a depth of 30 feet, encountering bedrock at 20 ft bgs. This well shares nearly identical location and construction information (and permit number) with the well registered to M WaterCo LLC and seems to be the same well. The parcel that this well sits on is owned by GWIP LLC, the property owner for this reclamation permit application. Permit number 1472 -R -R General Purpose well (1472 -R -R) is registered to West Weld Ag Investors. This well was originally drilled for Allen Lamb with permit number 1472 before 1957 and listed as an irrigation well. It was replaced by well 1472-R at an unknown date to a depth of 15 ft bgs, with a 40 ft by 60 ft sump from which water was pumped at approximately 500 gpm. A permit application was received in 1981 to replace well 1472-R with anew irrigation well by West Weld Ag Investors with a proposed maximum pumping rate of 500 gpm and a planned depth of 50 ft. The registered UTM coordinates for the well indicate that it is located several hundred feet south of the Cache la Poudre river, but the description in the permit indicates that it is located 3,300 ft south of the northern edge of OTETRA TECH Page 4111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 section 35 and 1,300 ft west of the eastern edge of section 35, and therefore may actually be located just north of the river near UTM 512260 E, 4476810 N. This location is approximately 1,200-1,300 ft west of the southwestern corner of the lease boundary, and approximately 1,500 ft from the nearest planned mining cell. A loop of the Cache la Poudre River extends between the lease area and the likely location for the well. Based on both a field and records investigation, the well listed at 1472 -R -R is believed to have been located near the irrigation center pivot, and abandoned at some time in the past. The parcel that this well sits on is owned by GNP LLC, the property owner for this reclamation permit application. Monitoring Wells on the Adjacent Parsons Mine Property Monitoring wells installed as part of the Parsons Mine operations were considered as part of this permit application. Twelve of the fourteen wells were installed in 2010 and the other two were installed more recently. Table 2 includes construction details and depth -to -water information. Measuring point elevations were surveyed on December 15, 2022, to the nearest 0.01 ft elevation. Appendix G-2 provides water levels measured over time for the Parsons Mine monitoring wells. 1.3.3 Site Monitoring Wells Martin Marietta installed five monitoring wells (Figure G-3) in August 2022 to support the monitoring plan associated with the project, documenting the groundwater conditions before initiation of mining, during mining, and after mining is complete. Through the well monitoring program, the wells will serve as points at which water levels will be measured and water quality samples collected. The boreholes for each of the wells were advanced until bedrock was encountered. Lithologic logs documenting the valley -fill sediments observed and the bedrock during drilling were recorded. The monitoring wells were constructed of two-inch Schedule 40 PVC casing and screen. Silica sand was placed from approximately two feet above the top of the screen to the bottom of the borehole (bedrock). Above the silica sand, a bentonite seal was placed in the borehole annulus to restrict infiltration of surface water. Each of the monitoring wells was finished at the surface with a locking, aboveground, steel protective casing set in concrete. Table 3 provides additional details on the monitoring well installations. Appendix G-1 presents borehole logs and well completion details for the monitoring wells. 1.4 HISTORIC AND FUTURE GROUNDWATER LEVELS Monitoring wells established at the Windsor East site in August 2022 were used to collect groundwater elevation data. This set of water level data was supplemented by water level data collected from monitoring wells on the adjacent Parsons Mine site located east of the Windsor East property. Water level data measured for the wells are included in Tables 2 and 3. Depth to water at the Windsor East site varies from 7.9 to 10.4 ft below the top of the well casing, corresponding to a range of water level elevation from 4732.14 at MW -06 to 4717.44 at MW -11. Figure G-5 presents the general direction of groundwater flow (southeast). Since 2010, regular groundwater measurements have been collected from the 14 monitoring wells around Martin Marietta's Parsons Mine site. These wells shall hereafter be referred to as the Parsons Well Network, and are numbered MW -1 through MW -14. Appendix G-2 shows the variation in water level measurements from monitoring wells MW -1 to MW -12. Water levels measured in the Parsons well network vary from 4730 feet at MW -5 to 4690 feet above mean sea level (amsl) at MW --1 where the effects of dewatering are visible in late 2021 through 2022. Water levels are seasonally at their highest elevations in August or September following the irrigation season, and typically at their lowest elevations in February to March when irrigation has been suspended for the longest period of time. The water level at MW -12 before initiation of local dewatering in 2019 ranged from 5.8 to 7.8 ft bgs (4720.5 to 4722 ft amsl), then dropped to an average of 11.3 ft bgs (4716.7 ft amsl), a drawdown of approximately 4.6 ft. This monitoring well is located approximately 100 feet from the dewatering trench of the nearest active mining cell at the Parsons Mine, and the 4.6 -foot change in water levels experienced at the Parsons Mine is expected to be representative of the drawdown that will be associated with dewatering of the mining cells at the Windsor East site. Based on observed water levels at the Windsor East and Parsons sites, dewatering will lower water levels to within 2 feet of the top of bedrock in the immediate vicinity of each mining cell. The lowered groundwater effects TETRA TECH Page 5111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 will be transmitted horizontally by the gravel aquifer, reducing water levels in the surrounding area as a "cone of depression" forms around the mining cell. During mining, water in the area will flow radially toward the dewatered cells, where it will be removed using the dewatering trench drainage system and discharged into the river. Following mining, each cell will be lined to form a hydraulically isolated reservoir. The effect of the clay liner on the groundwater within the aquifer will be the formation of a hydraulic mound upgradient of the cell where water levels will be several feet higher than under pre -mining conditions. Downgradient of the cell, the groundwater levels will be several feet lower due to a "shadow effect" behind the reservoir. These changes in groundwater levels due to the clay -lined cells are expected to have minimal effect on the groundwater in the surrounding area due to the proximity of the river adjacent to and downgradient of the lined cells. Downgradient of the lined cells, groundwater levels will reach an equilibrium with the river due to its proximity, thereby minimizing the "shadow effect". 1.5 AVAILABLE SATURATED THICKNESS The drilling and installation of monitoring wells at the Windsor East site in August 2022 indicated that bedrock was encountered between 15 and 22.5 feet below land surface. Water levels measured on August 12, 2022, ranged from 7.9 to 10.4 feet bgs. Based on this data, the saturated thickness of aquifer present beneath the site ranges from approximately 5 to 13.5 ft (Table 3). The lowest saturated thickness was recorded in MW -11 on the eastern side of the site, which is likely showing the direct impact of dewatering activities associated with the adjacent Parsons mine. Dewatering activities required as part of mining in the absence of a hydraulic barrier wall result in drawdown of the water table and associated decrease in saturated thickness of the alluvium. This has the potential to impact other wells nearby if the decline in water levels is sufficient to prohibit the well owner from extracting the associated water rights from the well. Table 4 presents historic information about the variability in saturated thickness near the site and the impact from mining based on available data. Four of the monitoring wells that were installed at the Parsons Mine Site to observe water levels at the Parsons Mine site, provide evidence of the saturated thickness of alluvium nearest to the Windsor East property. Water levels measured during pre -mining and mining conditions illustrate the expected decline in saturated thickness approximately 100 feet from the gravel mines. In particular, the Parsons Mine monitoring well MW -12 is located approximately 100 feet west of a cell that began dewatering and mining in 2019. The water level record for the well shows the range of saturated thickness for the alluvium before and during dewatering activities at this distance. MW -12 is located on the eastern edge of the Windsor East property and is therefore expected to be representative of the conditions at the site as well as of the expected impacts from dewatering during mining near the property boundary. Before 2019, the water table was an average of 6.3 feet above the top of the bedrock at MW -12 and fluctuated over a range of approximately 1 foot above or below this average. During dewatering, the depth to water increased, and the saturated thickness decreased until it was an average of 1.7 feet above the top of the bedrock, with a variation range of approximately 1 to 1.5 feet. Water wells completed in sand and gravel aquifers typically provide approximately 25 to 30 gallons per minute per foot of drawdown of saturated thickness in the well. Domestic wells are typically permitted for maximum pumping rates of 15 gallons per minute (gpm). As a result, less than 2 feet of saturated thickness above the pump intake is therefore likely to be required to provide the allowed pumping rates of 15 gpm. The reduction of saturated thickness of 4.6 ft at MW -12 to 1.7 ft above bedrock suggests that the potential for impact to a domestic well at this distance is likely, however, wells located further from the lease boundary will have more saturated thickness and hence will likely be able to pump the permitted rates. 1.6 HYDRAULIC IMPACTS The hydraulic impacts associated with dewatering around the planned mine cells are expected to spread outward as a function of the aquifer properties of the alluvium, the time elapsed since dewatering began, and the distance of observation from the point of dewatering. The previous observations of the depressed water table (drawdown) OTETRA TECH Page 6111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 due to mining at the adjacent Parsons mine (noted in the previous section) are useful for predicting the impact of the Windsor East mine. In particular, the observations at Parsons well MW -12 (located directly between a dewatered cell and the Windsor East site) represent an ideal location from which the effects of dewatering in the vicinity can be observed. As noted in Table 4, the result of dewatering at MW -12, located approximately 100 ft from the nearest cell, resulted in drawdown of 4.6 ft. This response occurred over two years, since dewatering was variable depending on mining rates. A water resources investigation (WRI) study performed by the United States Geological Survey (USGS) (Langer and Paschke, WRI 02-4267, 2002), explored the simulated spread of hydraulic impacts in a hypothetical situation involving the excavation of surface alluvium to bedrock (similar to most of the sand and gravel mine operations along the Front Range river corridors). Appendix G-4 shares this USGS WRI report. The study used analytical and numerical modeling of a pit near a river in a highly permeable unconfined aquifer. This study illustrated that in a hypothetical sand and gravel pit in an aquifer adjacent to a river, a numerical simulation of steady-state drawdown does not result in drawdown exceeding approximately 1 foot at a roughly 0.5 -mile distance from the hypothetical pit. There are no registered wells owned by parties other than Great Western or Martin Marietta within 0.5 miles of the Windsor East Mine property. As a result, there are no parties that are expected to be impacted as a result of either dewatering operations or subsequent development of lined ponds at the Windsor East Mine site. Therefore, detailed localized numerical modeling of hydraulic impacts has not been conducted.Additionally, there are likely mitigating factors to drawdown spread caused by dewatering. Active dewatering may stop and start at a location depending on the mining progress, the proximity of the Cache la Poudre River will provide a constant source of water mitigating drawdown impacts, and the aquifer may prove more or less transmissive depending on the location. With this understanding, the modeled spread of the hydraulic effects of dewatering suggests that the impact of the lowering of the water table during mining is unlikely to substantially affect any nearby water wells. 1.7 WATER USE Section 6.4.7 of the Colorado Mined Land Reclamation Board's Construction Material Rules and Regulations: (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. Water use will be at its highest during the mining phase of the project. Mining at the site will intercept groundwater tributary to the Cache la Poudre River. Consumptive uses of groundwater at the site include evaporation from groundwater exposed to the atmosphere, water retained in material hauled off -site for processing, and water used for dust control. Evaporative losses at the site are attributable to exposed groundwater in the dewatering trenches for each mine cell. Evaporative losses were calculated as the difference between gross evaporation and effective precipitation. The NOAA Technical Report NWS 33, Evaporation Atlas for the Contiguous 48 United States (U.S. Department of Commerce) was used to determine the site's average annual gross evaporation of 43 inches. Precipitation was obtained from the Western Regional Climate Center for the Fort Collins weather station (053005). The gross annual precipitation for this site was determined to be 15.08 inches. Effective precipitation was calculated as 70 percent of gross precipitation; thus, the average annual effective precipitation was determined to be 10.56 inches. The resulting evaporative loss rate is therefore 27.92 inches. The maximum total annual evaporative consumptive use at the site is estimated at 12-17 acre-feet, which is primarily a function of the water used for dust control (10-15 ac-ft/yr). OTETRA TECH Page 7111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 2.0 MONITORING AND MITIGATION PLAN This Groundwater Monitoring and Mitigation Plan is prepared as part of Martin Marietta's application to the Colorado Division of Reclamation, Mining and Safety (DRMS) for a permit for the Windsor East Mine in Weld County, Colorado. This plan presents the methods and locations for monitoring of groundwater during gravel mining and site reclamation activities. Although adverse impacts to other local users of groundwater are not expected due to activities at the mine, this plan addresses how any adverse effects to groundwater would be mitigated, should they occur. Martin Marietta will submit a Temporary Substitute Water Supply Plan to the State Engineer's Office for approval. The temporary substitute supply plan is designed to protect senior vested water rights and mitigate potential depletions of flows in adjacent waterways. 2.1 MINING PLAN Except for Cell A, the mining plan has been designed to allow for up to five quarters worth of groundwater monitoring to occur before excavation below the water table occurs. This monitoring includes monthly water level measurements in the five monitoring wells at the Windsor East Mine site, and five quarterly water -quality sample collection events. To allow for sufficient time for groundwater characterization to occur, mining is only planned to occur in the unsaturated zone until one year's worth of monitoring and groundwater sample collection has been conducted. An exception will be made for mine Cell A. This cell is the easternmost cell in the mining plan and is located within several hundred feet of the Parsons mine. As a result, water levels are already lowered in the area from Parsons dewatering. Since changes to the groundwater flow regime have already been substantially implemented, trenching and mining below the water table at Cell A with associated dewatering will begin before the five quarters of monitoring are complete. Based on the current mining schedule, mining will expose the water table after three quarters of monitoring has taken place. Following the five quarters of monitoring, dewatering trenches will be excavated around the perimeter of each remaining mine cell on a schedule determined by the mining plan. Dewatering will occur initially adjacent to the area on the east where dewatering associated with Parsons mine has already reduced water levels (Cell A). The bottom of the trench will be maintained at or deeper than the deepest point in the excavated mine cell, thereby intercepting all groundwater before it reaches the mine cell. After collection of five quarters of groundwater monitoring, mining will gradually progress westward, with perimeter dewatering drains preceding excavation below the water table. Groundwater flow into each dewatering trench will be accumulated in connected sumps and discharged directly into the Cache la Poudre River. Following completion of mining activities, mine cells A and C will be finished with a compacted embankment liner from material located on -site, keyed into the bedrock at the base of the mine cell, thus forming a low -permeability bathtub in the mine cell. Once finished, dewatering of the perimeter trench will cease, and the trench will be backfilled, allowing groundwater to return to a state of natural flow around the now -lined mine cell. It is expected that some minor hydraulic mounding may occur upgradient of the lined mine cell, with some "shadow effect" (decline in groundwater level) downgradient of the mine cell. Since no existing water wells have been identified downgradient between the mine and the river, the shadow effect is not anticipated to impact other users. Figure G-6 depicts the anticipated groundwater flow directions resulting from the installation of the compacted liners during reclamation. Mine cells B and D will be backfilled with non -economic aggregate. While this material is expected to be finer - grained than the existing subsurface sands and gravels being mined, they are not expected to represent a significant barrier to flow. Some minor hydraulic mounding may occur to the northwest of each of the cells, but the effect is presumed to be localized and limited to less than 2 feet relative to the surrounding water table. OTETRA TECH Page 8111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 2.2 MONITORING The monitoring plan will consist of regular data collection from the set of five monitoring wells installed around the perimeter of the Windsor East property (Figure G-3). Data collection activities will include monthly measurement of water levels in wells and quarterly sampling of water quality from wells and surface discharge locations for a minimum of five quarters. Following five quarters of background water quality sample collection and analysis, Martin Marietta will submit a summary of the water quality results to DRMS for review, and a formal request to reduce the analyte list and/or frequency for water quality sample collection, if appropriate. 2.2.1 Water Quality Parameters Martin Marietta will collect water samples from each of the wells and discharge outflow sites and submit the samples to an analytical laboratory to determine water quality for a set of parameters. As part of this process, notes will be recorded on field forms or in a logbook documenting the activities related to sample collection including date, time, measured water level, pre -sampling well purging details, and sample collection documentation. The DRMS recommends a set of parameters for analysis for aggregate mine permitting. These include a list of dissolved metals, radiological parameters, and miscellaneous parameters which include pH and total dissolved solids (TDS). The nature of activities associated with sand and gravel mining involves excavation of large volumes of aggregate materials using industrial machinery. These activities inherently do not result in the generation or release of coliform bacteria, asbestos, chlorophenol, foaming agents, odor, or phenol compounds. They also do not result in a change in corrosivity of water, or color change. As a result, these parameters which are otherwise a part of the DRMS requirements for water quality analysis are excluded from the list of water quality parameters. Likewise, sand and gravel mining does not lead to the generation or release of gross alpha or beta and photon emitters as part of the operation. Martin Marietta acknowledges the preference on the part of DRMS to have gross alpha radiological analysis performed and will include it in the list, but will exclude beta and photon emitters from analysis. Table 5 presents the complete list of water quality parameters proposed for analysis. Quality Assurance / Quality Control (QA/QC) samples will be collected as part of the monitoring program. Typical sampling programs may employ a range of samples for the purposes to confirm laboratory procedures, field conditions, sampling methodologies and consistency of data including trip blanks, field blanks, field duplicates. Trip blanks consist of a laboratory pre -filled volatile organic analysis (VOA) 40 mL bottle which is transported in the same coolers with the samples between the water source and the laboratory to determine whether volatile organic compounds (VOCs) are a product of the sample containment and transportation process. Field blanks are sample bottles filled using deionized or distilled water previously obtained from a laboratory and filled on site to evaluate whether the process of sample collection is a source of dissolved constituents, and are typically analyzed primarily for VOCs. Field duplicates represent a paired sample collected at the same time as the primary sample, using the same sized bottles and run for a similar set of analysis to determine whether variation due to sample collection and laboratory analysis procedures result in a significant range in analytical results. Martin Marietta will collect one field duplicate per sampling event for QA/QC purposes, but since VOCs are not a part of the sampling program, trip blanks and field blanks will not be collected. 2.2.2 Windsor East Monitoring Wells The monitoring plan will consist of regular data collection from the five monitoring wells installed around the perimeter of Windsor East (Figure G-3). Monitoring data will be used to identify potential changes in alluvial groundwater flow or elevation associated with mining and reclamation activities. Baseline data collected from the monitoring program will provide a range of relative water levels associated with pre -mining groundwater conditions. Experience at other sand and gravel mine sites in similar geologic settings shows that groundwater levels tend to fluctuate between two to four feet each year; levels are highest in the summer and lowest in the winter and early spring. Martin Marietta will conduct monthly water level monitoring for the five monitoring wells around Windsor East during dewatering and until groundwater levels have recovered once dewatering ends. OTETRA TECH Page 9111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 Groundwater samples will be collected to document baseline water quality prior to mining, then determine whether any changes have occurred as a result of mining activities. One quarterly water quality sample for laboratory analysis will be collected during each of the five quarters of monitoring to document the baseline water quality around the mine. Based on the historical water level fluctuations observed in the wells associated with the Parsons Mine, the seasonal high and low water levels for groundwater have been evaluated. Water levels are seasonally at their highest elevations in August or September following the irrigation season, and typically at their lowest elevations in February to March when irrigation has been suspended for the longest period of time. During high groundwater levels, the sample is expected to be representative of the groundwater which flows from the agricultural fields toward the river, and during the periods of low groundwater the sample is expected to be representative of alluvial channel water flowing from the west. After five quarters, water quality sample collection will continue to be conducted twice per year while mining, with sample collection timed to be consistent with high and low groundwater levels. The results of water quality sample analysis will be provided to DRMS following the baseline water quality evaluation, and during annual reporting thereafter. Appendix G-3 includes procedures for collecting water samples. These procedures include a process of pumping to purge standing well water, then using the pump to remove water for sample collection, then placing the water in sample bottles obtained from the analytical laboratory. At the end of purging, the pH of the water will be recorded using a handheld pH meter. Samples for dissolved constituents, primarily inorganics and metals, will first be filtered through a 0.45 -micron filter to remove suspended solids. Samples will then be stored on ice in a cooler for transport and submitted for analysis of the constituents listed in Table 5 under chain -of -custody protocols. If sufficient data is collected during the life of the mining operation, and a demonstration can be made that project impacts to the groundwater system have been minimized, Martin Marietta may request the approval of a Technical Revision to revise the water level monitoring frequency or water quality sample collection frequency at a later date. 2.2.3 Domestic and Irrigation Water Wells No active water wells (water -supply wells) were present within 600 ft of the lease area. 2.2.4 Dewatering Discharge Based on data collected from monitoring wells on the adjacent Parsons Mine property, the depth to groundwater fluctuates by two feet depending on the season but averages about 7 feet below ground surface. Due to the absence of large quantities of potential pollutants on site (no on -site processing or concrete or asphalt production), the mining and reclamation operations are not likely to affect groundwater quality on or off the site. Martin Marietta's Parsons facility complies with applicable requirements in the site CDPS General Permit COG501594 for Discharges Associated with Sand and Gravel Mining and Processing. CDPHE WQCD considers stormwater runoff combined with mine dewatering water to be process water. Current discharges at the Martin Marietta Windsor East Site and Parsons Pit are permitted as process water. As such, process water discharges are subject to the process water provisions in the general permit. Martin Marietta plans to obtain a City of Windsor Grading, Erosion and Sediment Control Plan (GESCP) Permit and comply with applicable requirements as stated in the City of Windsor's Municipal Code/Ordinance Chapter 13, Article, Stormwater Quality. 2.3 MITIGATION The available monitoring well data will be used to identify changes in alluvial groundwater flow associated with mining and reclamation activities. Baseline data collected from the monitoring program will provide a range of relative water levels associated with pre -mining groundwater conditions. These data will be utilized to evaluate the nature and extent of the change to the prevailing hydrologic balance and if necessary, provide for the development of corrective actions. Well owners in the section below refer specifically to owners of wells from which extracted water is put to beneficial use, such as water wells, irrigation wells, etc. Owners of monitoring OTETRA TECH Page 10111 Windsor East Mine, Exhibit G — Water Information April 3, 2023 wells are not considered well owners in this context since a change in water levels for these wells does not represent material damage. In the event of a well owner complaint, Martin Marietta commits to reporting any complaints received from well owners to the DRMS within 48 hours, investigating the complaint as soon as practical, and submitting the results to the DRMS for evaluation within 30 days. For the investigation, the first level of response will be to review water level data from the monitoring well network and, if available, a measurement of the water level in the plaintiff's well. Information will be evaluated to determine the plaintiff's complaint may be tied to dewatering or the lined reservoirs. If the data indicates that there is no reason to believe the plaintiffs well was impacted by dewatering or the lined reservoirs, that will conclude the action taken by Martin Marietta. If the data does not clearly show there is no impact, as a second level of response, Martin Marietta will present a contract to the well owner requesting access to the well to perform mechanical and electrical inspection and testing of the well and associated system, e.g. pressure tank. The agreement will explain that if the problem with the well is not due to a lower water level and is instead due to a mechanical or electrical issue, the well owner will be responsible for the repairs. If the well is determined to be in good working order and the problem is due to a lower water level, then the mining -associated impacts will be addressed to the satisfaction of the DRMS. If the DRMS determines that the impact on a well for which temporary mitigation has been initiated is not a result of Martin Marietta's activities or is not solely a result of Martin Marietta's activities, Martin Marietta will reduce or cease mitigation accordingly. In the event of a complaint that a well has become unusable, and based on the inspection results described above, Martin Marietta will implement mitigation measures within 7 days. Mitigation measures would include providing a temporary alternative water supply that meets the documented historic well production or need until further investigation can be conducted to determine if the well condition is due to the mining operation. The DRMS, and potentially the Mine Land Reclamation Board (MLRB), are responsible for determining if mitigation is required, as well as when and how any mitigation measures are implemented and discontinued after the initial complaint is received. Should DRMS or MLRB conclude that mitigation action is required, Martin Marietta will begin to implement one or more mitigation measures. Temporary mitigation measures may include, but are not limited to: Compensation for well owners to use their existing treated water system to replace the well production loss; Provision of a water tank and delivery water as necessary to meet documented historic well production or need; and Other means acceptable to both the well owner and Martin Marietta. Long-term mitigation measures may include, but are not limited to: • Cleaning a well to improve efficiency. • Providing an alternative source of water or purchasing additional water to support historic well use with respect to water quantity and quality. If needed, water quality parameters will be checked in affected wells to ensure alternative sources support the historic use. • Modifying a well to operate under lower groundwater conditions. This could include deepening existing wells or lowering the pumps. All work would be completed at Martin Marietta's expense except for replacing equipment that was non-functional prior to mining. • If existing wells cannot be retrofitted or repaired, replace the impacted well with a new replacement well. • Design and installation of a cistern. If a groundwater mitigation action is required, Martin Marietta will notify the DRMS of the condition, action taken and report the results and present a plan for monitoring the mitigation. OTETRA TECH Page 11111 n TETRA TECH April 3, 2023 Peter Hays Division of Reclamation, Mining and Safety 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Response to 3rd Adequacy Review Comments for Martin Marietta Materials, Inc., Windsor East Mine, File No. M-2022-042, 112c Permit Application Dear Mr. Hays: This letter is in response to your 3rd Adequacy Review Letter, dated March 24, 2023, regarding Martin Marietta Windsor East Mine's 112c Permit Application (File No. M-2022-042). Please find our responses below. Comments 6.4.6 Exhibit G - Water Information 1. On March 22, 2023, the Division sent a copy of the Summary of Adequacy Response Review letter from Eric Scott dated March 17, 2023 regarding Exhibit G. Please respond to the comments contained in the letter. Response Acknowledged. A separate letter (2'1 Adequacy Review Response) contains the responses to Eric Scott's comments regarding Exhibit G. 6.4.12 Exhibit L - Reclamation Costs 2. The Division calculated the cost for an independent contractor to reclaim the site based on the information provided by the Applicant in the permit application at $2,300,000.00. A copy of the Division's bond estimate is attached for review. Response Martin Marietta accepts the Division's bond estimate that was provided. 6.4.18 Exhibit R - Proof of Filing with County Clerk and Recorder 3. Please provide an affidavit or receipt indicating the date on which the revised application information required to address this adequacy letter and the second adequacy letter dated March 22, 2023 were placed with the Weld County Clerk and Recorder for public review, pursuant to Subparagraph 1.6.2(1)(c). Response Attached is a copy of the receipt documenting that the Adequacy Review 2 and 3 response documents were filed with the Weld County Clerk to the Board's office. Please be advised the Windsor East Mine application may be deemed inadequate, and the application may be denied on April 17, 2023, 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 April 17, 2023 and request for additional time. This must be received no later than the decision date. TETRA TECH page 1 of 2 DRMS Adequacy Review 3 Response April 3, 2023 Unless you should need more time to review ourAdequacy Review 2 and 3 responses, the decision date should work, and no additional time is needed. Please let us know if for any reason you need additional time to review and approve the application. Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH Pamela Franch Hora, AICP Senior Planner cc: Julie Mikulas, Martin Marietta D:1Projects\Longmont87411117-8741006Docs\DRMS\AdequacyReview3 Responses\2023 0403 Adequacy Response DRMS.docx TETRA TECH page 2 of 2 Martin Marietta April 6, 2023 Weld County Clerk to the Board's Office 1150 O Street Greeley, CO 80631 Julie Mikulas Regional Land Manager RE: Notice of Application for a Mined Land Reclamation Permit (M-2022-042), County Copy of Public Notice Documents To Whom It May Concern: Enclosed are revised pages for the 112(c) application to the Colorado Division of Reclamation, Mining and Safety for our Windsor East Mine that were delivered to you on September 22, 2022 and October 6, 2022 and March 3, 2023. Copies of these revised pages are being delivered to you pursuant to 34-32.5- 112(9)(a), C.R.S., as amended. The revised pages should be made available for public review along with the application that was delivered on September 23, 2022 and the revisions on October 6, 2022 and March 3, 2023 until the permit has been approved by the Division of Reclamation, Mining and Safety. Please acknowledge receipt of the public notice documents by signing below. Sincerely, Julie Mikulas Regional Land Manager RECEIVED THIS DAY OF 2023. Weld County Clerk to the Board By: Name: RECEIVED APR a6 2023 Title: WELD COUNTY ( flM nISSIONERS Rocky Mountain Division — Northern Office 1800 N Taft Hill Road, Fort Collins, CO 80534 julie.mikulas@martinmarietta.com www.martinmarietta.com Martin Marietta March 3, 2023 Weld County Clerk to the Board's Office 1150 O Street Greeley, CO 80631 Julie Mikulas Regional Land Manager RE: Notice of Application for a Mined Land Reclamation Permit (M-2022-042), County Copy of Public Notice Documents To Whom It May Concern: Enclosed are revised pages for the 112(c) application to the Colorado Division of Reclamation, Mining and Safety for our Windsor East Mine that were delivered to you on September 22, 2022 and October 6, 2022. Copies of these rervised pages are being delivered to you pursuant to 34-32.5-112(9)(a), C.R.S., as amended. The revised pages should be made available for public review along with the application that was delivered on September 23, 2022 and the revisions on October 6, 2022 until the permit has been approved by the Division of Reclamation, Mining and Safety. Please acknowledge receipt of the public notice documents by signing below. Sincerely, Julie Mikulas Regional Land Manager RECEIVED THIS DAY OF 2023. Weld County Clerk to the Board By: RECEIVED Name: Title: MAR 0 3 2023 WELD COUNTY COMMISSIONERS Rocky Mountain Division - Northern Office 1800 N Taft Hill Road, Fort Collins, CO 80534 julie.mikulas@martinmarietta.com www.martinmarietta.com Pvbl : G Rev;ec,J C:PL.(TP/MN/DA/Ko/DA), pw(Gr1/ER/ DN /Db) O3/2O/23 03/27/23 2o22 - 22 c13 Windsor East DRMS Regular 112 Operation Reclamation Permit Application to the Colorado Division of Reclamation, Mining, and Safety March 2023 revisions APPLICANT: Ak, Martin Marietta Martin Marietta Materials, Inc 1800 North Taft Hill Road Fort Collins, Colorado 80524 REPRESENTED BY: [I) TETRA TECH 351 Coffman Street, Suite 200 Longmont, CO 80501 (303) 772-5282 TETRA TECH March 3, 2023 Peter Hays Division of Reclamation, Mining and Safety 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Response to Adequacy Review Comments for Martin Marietta Materials, Inc., Windsor East Mine, File No. M-2022-042, 112c Permit Application Dear Mr. Hays: This letter is in response to your Adequacy Review letter, dated December4, 2022, regarding Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). Please find below our responses to the Adequacy Review comments. Comments 1. The Division state agency comments from History Colorado, Colorado Parks and Wildlife, Army Corps. of Engineers and Division of Water Resources (2). Copies of the letters are attached. Please address the comments and revise the application accordingly. Response We have prepared and sent responses to each of the referral agencies. Copies of the response letters are attached. 1.6 PUBLIC NOTICE 2. Pursuant to Rules 1.6.2(1)(d) and 1.6.5(1), please submit proof of publication in a newspaper of general circulation in the locality of the proposed mining operation. As you stated in your adequacy letter, "The Applicant submitted proof of publication via email to the Division on November11, 2022. No additional response is required by the Applicant." 3. Pursuant to Rule 1.6.2(e), please submit proof of the notice to all owners of record of surface and mineral rights of the affected land and the owners of record of all land surface within 200 feet of the boundary of the affected land including all easement holders located on the affected land and within 200 feet of the boundary of the affected land. Proof of notice may be return receipts of a Certified Mailing or by proof of personal service As you stated in your adequacy letter, "The Applicant submitted proof of notice to the owners of record of all land surface within 200 feet via email to the Division on November11, 2022. On November29, 2022, the Applicant provided Division with the return receipts of the certified mailings or other documentation for all owners of record including easement owners. No additional response is required by the Applicant." 6.4 SPECIFIC EXHIBIT REQUIREMENTS - Regular 112 Operations 6.4.5. EXHIBIT E - Reclamation Plan 4. The Applicant states the site will be mined and reclaimed to create two water storage ponds and all mine walls will be re -graded with overburden material to create a compacted liner. Please submit the design specifications for the proposed clay liners in accordance with the August 1999 State Engineer Guidelines for Lining Criteria for Division review. TETRA TECH pages of 5 DRMS Adequacy Review 1 Response March 3, 2023 During the pre -operational inspection, the Applicant stated the design of the clay liner for the reservoirs would be designed prior to the construction of the liner. Please commit to providing a copy of the clay liner design as a technical revision for Division review and approval prior to the construction of the liner. Response A cross-section illustrating the proposed design for the liner has been incorporated into Exhibit E. In addition, Exhibit E has been revised to indicate that a copy of the clay liner design will be submitted to the Division for review and approval, through a Technical Revision process, prior to construction of the liner. 6.4.7 EXHIBIT G - Water Information 5. A copy of the review memo for the content of Exhibit G - Water Information from Eric Scott dated October 14, 2022 was sent to the Applicant on October 31, 2022. Please provide a response to the memo questions. Response Attached is a copy of a letter responding to Eric Scott's Exhibit G comments. 6. In Section 2.1 Mining Plan, the Applicant states to allow sufficient time for groundwater characterization to occur, mining is only planned to occur in the unsaturated zone until one year's worth of monitoring and groundwater sample collection has been conducted. During the pre -operational inspection, the Applicant stated the mining operations would be conducted in the saturated zone sooner than originally planned by the Applicant. Please update Exhibits D and G to describe when the mining operations will occur below the groundwater elevation. Response Exhibits D and G have been updated to explain when the mining operations will occur below the groundwater elevation. A revised copy of Exhibits D and G are attached. 7. In Section 2.2.2, the Applicant states the results of water quality sample analyses will be provided to DRMS following the baseline water quality evaluation. Please commit to providing the results of the water quality sample analysis as a technical revision for Division review and approval when available. Response Section 2.2.2 has been edited to indicate that results of the water quality sample analysis will be submitted as a Technical Revision for the Division to review and approve, when the information is available. 6.4.8 EXHIBIT H - Wildlife Information 8. Please commit to following the Pinyon Environmental, Inc. recommendations related to state -listed and special concern species in Attachment H-1 and update Exhibits C and D accordingly. Response The Pinyon Environmental, Inc. recommendations related to state -listed and special concern species in Attachment H-1 will be followed. We have updated Exhibits C and D accordingly. 6.4.12 EXHIBIT L - Reclamation Costs 9. The Applicant included the cost to fertilize the reclaimed land in the reclamation cost estimate. The proposed Reclamation Plan states the Applicant will follow the recommendations, if any, of the SCS. Please provide a description of the fertilization, specify types, mixtures, quantities and time of application pursuant to Rule 6.4.5(2)(f)(iii). TETRA TECH page 2 of 5 DRMSAdequacy Review 1 Response March 3, 2023 Response At this time, it is not known if fertilizing will be needed. Before seeding, a soil test will be completed to determine if it is necessary so we cannot give types, mixtures, and quantities at this time. This item has been removed from the cost estimate. We had just added a little cost in case it was needed. 10. The proposed Reclamation Plan states all upland areas will be mulched with 1 ton of certified weed free straw per acre. Please include the mulching costs in the reclamation cost estimate. The Division recommends using 2 tons per acre of mulch. Please contact the SCS for a mulching rate recommendation and update Exhibits E and L accordingly. Response Seed mix and mulching rates approved for the adjacent Parsons Mine M-2009-082, called for 1 ton of certified weed free straw per acre and we just cut and pasted that seed mix and mulching recommendation into this application to be consistent. Mulch can be an issue with contaminating the aggregate when we are reclaiming in phases before all the mining is completed. Parsons Mine was permitted over 10 years ago, and we have reached out to the SCS to see if this is still the preferred mix and rates. We have not heard back from them. When they get back to us, if they have changes, we will submit a technical revision. 11. Please provide all information necessary to calculate the costs of reclamation, including the typical equipment utilized for each reclamation task, to allow the Division to calculate the cost of reclamation that would be incurred by the state. Response Equipment utilized for overburden and topsoil will be contracted out but typically is done with a scraper. Disking or Scarifying, Grass Drilling and Mulching are typically contracted out and they use agricultural tractors 200HP. Liner installation is also contracted out and the equipment used will be determined by the contractor. Our costs reflect the equipment included in the items. 6.4.13 EXHIBIT M - Other Permit and Licenses 12. Please commit to providing copies of all required and approved permits and licenses to the Division when available. Response Exhibit M has been revised to indicate that the operator will provide all required and approved permits and licenses to the Division when available. In addition, the list of permits required has been updated to eliminate the permits that are no longer required (an SPCC Plan because a fuel storage tank is no longer planned to be kept at this site and the Town of Windsor determined that a Grading, Erosion, and Sediment Control Plan will not be needed). 6.4.18 EXHIBIT R - Proof of Filing with County Clerk and Recorder 13. 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). Response Attached is a signed affidavit indicating that these revised application information materials were placed with the Weld County Clerk and Recorder for public review. 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 structures, the Applicant may either: a. 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 TETRA TECH page 3 of 5 DRMS Adequacy Review 1 Response March 3, 2023 b. 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 c. 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. The Division will require the Applicant to demonstrate 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, prior to the Division's consideration of a stability analysis. Response Acknowledged. 14. Please provide the Division with copies of all signed structure agreements with the owners of permanent man-made structures within 200 feet the proposed affected area boundary. Response Attached are copies of the signed structure agreements that Martin Marietta received back from the owners of permanent man-made structures within 200 feet the proposed affected area boundary. 15. The Applicant lists Martin Marietta Materials, Inc. as a structure owner on Exhibit C-2. Please update Exhibit S to include Martin Marietta Materials, Inc. as an owner of man-made structures within 200 feet of the affected area. Response Exhibit S has been updated to list Martin Marietta Materials as an owner of man-made structures within 200 feet of the affected area. 6.5 GEOTECHNICAL STABILITY EXHIBIT 16. The Division reviewed and will accept the stability analysis demonstrating the require offsets from the structures within 200 feet of the affected area of the proposed mine site if the Applicant is unable to obtain notarized structure agreements with all owners. Response Acknowledged. As part of the process to permit the site through the Town of Windsor, we made some minor modifications to the mining and reclamation plan maps. As a result, revised versions of Exhibits C and F are attached. The specific changes we made included: • Exhibit C: We added some potential water service lines (structure number 51) to sheet C-2. The City of Greeley's historic mapping shows these lines; however, the property owners that are connected to the lines indicated they do not exist as Greeley's mapping shows. The service lines would need to be potholed to locate them. This will be completed prior to mining. If the lines are found to be located where the City of Greeley's mapping shows them to be, the lines will either be relocated or Cell D will not be mined. • Exhibit F: The reclamation topography for the water storage reservoirs was modified to incorporate more curves at the shoreline. In changing the topography, the size of the reservoirs slightly decreased. The acreage information was updated on both sheets of Exhibit F. TETRA TECH page 4 of 5 DRMS Adequacy Review 1 Response March 3, 2023 Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH c-fa/inaix Pamela Franch Hora, AICP Senior Planner cc: Julie Mikulas, Martin Marietta 0: \Projects1 Longmont187411117-8741000DocsI DRMSVAdequacy Review 1 Responses\ Updated Exhibits12023 03 03 Adequacy Response 1 DRM5. docx TETRA TECH page 5 of 5 El TETRA TECH March 3, 2023 Peter Hays Eric Scott Division of Reclamation, Mining and Safety 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Martin Marietta Materials, Inc., Windsor East Mine, File No. M-2022-042, Exhibit G - Water Information Review Memo Dear Peter Hays and Eric Scott: This letter is in response to the Adequacy Review letter specific to Exhibit G, Water Information, dated October 31, 2022, regarding Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). Please find below our responses to the Adequacy Questions/Issues identified in Exhibit G. Comments 1. What will cells B and D be backfilled with and how? The narrative implies that these areas will be as permeable as native materials and pose no impediment to GW flow when mining is completed, however if they are backfilled with wash fines, or the backfill is compacted during placement, it is much more likely that they will create a similar barrier to GW flow as the lined cells along with the same potential impacts due to mounding/shadowing. Response Cell B and D will be backfilled with overburden from the site. Martin Marietta typically contracts the work out, so depending on what they have available, it will either be a scraper or a truck and dozer placing the overburden. While the backfill material is likely to be somewhat finer grained than the gravel deposits being excavated, the material is not anticipated to represent a significant barrier to flow. It may cause some minor hydraulic mounding, but not to the extent that it will require mitigation. The potential mounding of water upgradient of cells B and D will be monitored as part of the post -mining water level program. An acknowledgement of this potential will be added to Exhibit G. If monitoring shows that hydraulic mounding is causing the water table to rise to within 4 feet of land surface resulting in the potential for surface flooding, Martin Marietta will investigate and address the issue using mitigation measures such as a perimeter drain. 2. There seems to be a great deal of uncertainty about the location of well 1472 -R -R, up to and including what side of the river it is on. The location of this well should be field verified so that it can be accurately shown on the provided maps, and potential impacts be more accurately determined. Response A records search indicated that the well registered as 1472 -R -R was likely installed as a replacement well on a property purchased by the Great Western leaseholder and the well inspector was not able to locate a well south of the river. Martin Marietta conducted a field search to locate this well and was unable to find an existing well. Some evidence that an irrigation supply well had been abandoned near the center pivot for the former agricultural field in the area was located on the north side of the river. As a result, Martin Marietta and Great Western believe that the well no longer exists. 3. All of the baseline GW level, flow direction data, and estimated flow mapping presented in this exhibit is derived from WL data collected from the adjacent Parsons site. However, it is stated that the measuring TETRA TECH page 1 of 4 DRMS Adequacy Review 1 Response Exhibit G March 3, 2023 point elevations for the Parsons wells were "estimated from topo maps". Basing this kind of data presentation on "estimated" elevations from topo maps is not consistent with industry standards or the TSOP presented in the provided exhibit. For DRMS to be able to consider water level data from the Parsons site in this review, all measuring points should be surveyed to 0.01' (and tied to the same reference elevations as the WEM wells), the historic readings recalculated, and the associated tables and figures re-created as needed. a. It appears that the 5 new WEM wells have been properly surveyed as the elevations are given to 0.01', however this should be confirmed. b. All subsequent WL readings collected at the WEM and Parsons sites should be recorded to the nearest 0.01', not just the nearest tenth of a foot as shown in the provided materials. This would also be consistent with the provided TSOP. Response The five monitoring wells in the Windsor East monitoring network are all surveyed to an accuracy of 0.01 feet of elevation. In December, the Parsons mine monitoring well network was also surveyed to the same accuracy and datum. The tables and figures provided in Exhibit G have been updated to reflect the new casing measuring point elevations. 4. Section 1.6 of the provided materials describes a "simplified model" and states that it was calibrated/verified based on observed drawdown in one well. This model is then used to predict groundwater drawdowns due to mining after one year and 5 years of dewatering at distances up to 2640 feet. DRMS will require a substantially more rigorous modelling demonstration to predict and illustrate the maximum groundwater drawdown impacts from dewatering during mining, potential impacts to nearby wells, as well as any post -mining mounding and shadowing impacts due to the construction of impermeable or low permeability mine cells. The model should provide GW drawdown/mounding contour maps based on, and verified against all available site setting and geologic information, current and historic water level data, and the predicted size and location of mining cells (for both sites). Response Based on subsequent conversations with the DRMS, Exhibit G will be updated to reflect that there are no registered wells owned by parties other than Great Western or Martin Marietta within 0.5 miles of the Windsor East Mine property (a letter from GWIP, the property and well owners documenting this has been included in Exhibit G as Appendix G-5). We understand that the DRMS agrees that the need for detailed modeling is therefore no longer critical because the potential for mining -induced drawdown will not result in injury to another party's nearby well. Additionally, a study done by the United States Geological Survey (Langer and Paschke, WR102-4267, 2002), discussing analytical and numerical simulation of the hydrologic effects of mining aggregate in hypothetical sand -and -gravel and fractured crystalline -rock aquifers, will be referenced and attached to Exhibit G. This study illustrates that a numerical simulation of steady-state drawdown in a hypothetical sand and gravel aquifer adjacent to a river does not result in drawdown exceeding approximately 1 foot at a roughly 0.5 -mile distance from the hypothetical pit. 5. Section 2.1 of the provided exhibit states that up to 5 quarters of "baseline" GW level data will be collected for the WEM site with the exception of Cell A where dewatering will commence immediately. This is based on the rationale that GW levels in that area have already been impacted by the adjacent Parsons dewatering activity. DRMS acknowledges that the historic GW regime has likely already been impacted to some extent by the adjacent Parsons site. However, based on the observations of significant GW drawdowns at distance from the Parsons site, allowing dewatering of Cell A while attempting to collect "baseline" water level data for the remainder of the WEM site will likely render that data useless as a "baseline" for later mining drawdown comparison. Dewatering or exposure of GW should not be allowed on the WEM site until the full 5 quarters of baseline data can be collected. TETRA TECH page 2 of 4 DRMS Adequacy Review 1 Response Exhibit G March 3, 2023 a. Mining below groundwater/dewatering of CellA during collection of the 5 quarters of baseline data may also adversely impact the validity of the baseline analytical data results. Response Evaluation of drawdown relative to undisturbed baseline conditions in the vicinity of the Windsor East Mine property is not an issue of concern for this project because there are no water wells located within 0.5 miles of the mine that are owned by parties other than Great Western Holdings (the landowner from whom Martin Marietta is leasing the land for mining). Martin Marietta commits to collect monthly water levels for five quarters and report these to the DRMS for pseudo -background evaluation purposes. Martin Marietta acknowledges that these water level measurements will likely be partially affected by dewatering that has been occurring on the Parsons Mine property. In addition, the measurements will also likely be further influenced by the dewatering of Windsor East Cell A which is expected to begin after only three of the five quarters of water quality sampling will have been conducted. Martin Marietta does not believe that the dewatering of Cell A will have any effect on the baseline analytical data results. 6. Water Quality Parameters and rationale presented in section 2.2.1 and Table 5 are acceptable as presented with the following edits. a. Add CN to section 2.2.1 or sample for it. b. WQS for U should be 0.0168 to 0.03, not 0.02 as stated in Table 5 c. Will any QA/QC samples be collected/run to verify field and lab procedures? d. I note that although there are several wells on the adjacent Parsons site, no analytical data has been presented as "background" for WEM, however, that may be a subject for another discussion. Response CN was added to the list of parameters for analysis and sampling to test for CN began as of November2022. The WQS for uranium will be updated in Table 5 based on the comment above. QA/QC samples will be collected including a trip blank and a field duplicate for each sampling event. 7. Section 2.2 (as well as 2.2.2) states that "regular data collection" from the 5 new GW wells will take place, but does not specify what that means. I would suggest that WL data be collected at least monthly and analytical sampling be conducted quarterly (as stated) until the 5 quarters of baseline data have been obtained. Analytical sampling intervals after the initials quarters are acceptable as presented. Response Exhibit G will be updated to reflect that water level measurements will be performed monthly for five quarters, and that water samples will be collected for baseline analysis quarterly, for flee quarters. 8. All baseline data as well as any proposed modifications to the analyte list or sampling intervals should be submitted to DRMS as a TR for review and approval. Response Comment acknowledged. 9. Section 2.3 states that "in the event of a well owner compliant within 600' of the affected area" MM will submit a report to DRMS within 30 days. DRMS does not restrict the radius of impact to 600' and therefore will require MM to commit to reporting any complaints by well owners to DRMS within 48 hrs or less. MM will be required to initiate an investigation into the complaint immediately and submit the results to DRMS for evaluation within 30 days. Response Exhibit G has been amended to note that any complaints by well owners will be reported to the DRMS within 48 -hours, Martin Marietta will initiate an investigation into the complaint as soon as practical, and submit the results of the investigation to the DRMS within 30 days. Language specifying the process for the TETRA TECH page 3 of 4 DRMS Adequacy Review 1 Response Exhibit G March 3, 2023 investigation, how water levels in the area will be monitored, and comparison to baseline water levels will be provided as part of the Monitoring and Mitigation Plan. 10. Section 2.3 also states that "if a well goes dry, MM will implement mitigation measures within 7 days." In the event that a well owner reports that their well has become unusable, MM will be required to implement mitigation measures immediately (as soon as practically possible). MM will concurrently commence an investigation into the status of the complaint. The results of this investigation as well as any proposed remediation or rationale for discontinuing mitigation will be submitted to DRMS for approval within 30 days. Response Martin Marietta has revised Exhibit G committing to report any complaints from well owners to the DRMS within 48 -hours, initiating an investigation into the complaint as soon as practical, and submitting the results of the investigation as well as any proposed remediation or rationale for discontinuing mitigation to the DRMS within 30 days. If a well owner reports that their well has become unusable, Martin Marietta will investigate and implement mitigation measures immediately provided that the investigation indicates that mitigation measures are needed. Examples of mitigation measures such as a temporary alternative water supply sufficient to meet documented historic well production will be identified in the Monitoring and Mitigation Plan. 11. Appendix G-3: Because the analyte list and reporting levels have been identified, please identify and include the sample container type and size, preservative (if required), holding times, and analytical method to be used. This information could also be included in Table 5. Response This information has been included as part of Table 5 of Exhibit G. 12. Field forms or logbooks should be used to record GW well purging and field sampling data consistent with industry standards. Response Comment acknowledged. These practices are standard and will be followed. Exhibit G has been revised to note that field notes will be recorded as part of the field sample collection process including notes on the pre - sampling purge activities. Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH tlotuit4uAp jr P.G. Ar Christop Gutmann, (Arizona) Hydrogeologist cc: Julie Mikulas, Martin Marietta Pam Hora, Tetra Tech 0: \Projectsllongmont38741 1117-8741006\Doc5DRMS\Adequacy Review 1 Responses\2023 03 03 Adequacy Response 1 DRMS Exhibit G Comments. docx TETRA TECH page 4 of 4 fjiJ TETRA TECH March 1, 2023 Dawn DiPrince State Historic Preservation Officer and Holly McKee -Huth Cultural Resource Information History Colorado 1200 Broadway Denver, CO 80203 Sent via Email to: holly.mckee@state.co.us RE: Windsor East Mine, File No. M-2022-042 (HC#82104) Dear Dawn DiPrince and Holly McKee -Huth: This letter is in response to History Colorado's comment letter in response to Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). Below is your comment followed by Martin Marietta's response. Comment A search of our database indicates that no properties of historical significance included or nominated for inclusion in the state register have been recorded within the proposed permit area. Please note, as most of Colorado has not been inventoried for cultural resources, our files contain incomplete information. Consequently, there is the possibility that as yet unidentified cultural resources exist within the proposed permit area. The requirements under CRS 24-80 part 13 apply and must be followed if human remains are discovered during ground disturbing activities. Response Acknowledged. Thank you for your consideration. Martin Marietta will contact you if any Cultural Resource Information/Section 106 Compliance questions should arise. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH Pamela Franch Hora, AICP Senior Planner cc: Peter S. Hays, DRMS Julie Mikulas, Martin Marietta O:Wrojects1Longmont187411117-87410061DocsIDRMSDdequacyReview1 Responses1DRAFT Adequacy Response History Colorado.dou TETRA TECH page 1 of 'l TETRA TECH March 1, 2023 Kiel Downing Department of the Army Corps of Engineers, Omaha District Denver Regulatory Office 9307 South Wadsworth Blvd Littleton, CO 80128 RE: Section 404 of the Clean Water Act Initial Comments Dear Kiel Downing: This letter is in response to the Army Corps of Engineers comment letter on Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). The letter below details your comment followed by Martin Marietta's response. Comments If the activity you described would impact waters of the United States, the Denver Regulatory Office should be notified. Please include a map identifying dimensions of work in each aquatic site, the county, Township, Range and Section and the latitude and longitude of the activity in decimal degrees, along with a description of your request, to the Denver Regulatory Office mailbox located at DenverRegulatoryMailboximusace.army.mil or contact the Denver Regulatory Office at 303-979-4120. Response Martin Marietta and their consultant, Pinyon Environmental, worked with the Army Corps of Engineers and it was determined that the wetlands on the site were not jurisdictional. Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH Pamela Franch Nora, AICP Senior Planner cc: Peter S. Hays, DRMS Julie Mikulas, Martin Marietta C4Projects\longmont187411117-87410061 DocsI DRMSDdequacy Review 1 Responses1 DRAFT Adequacy Response 1 Corps.docx TETRA TECH page 1 of 1 iij TETRA TECH March 1, 2023 Brandon B. Marette Colorado Parks and Wildlife 6060 Broadway Denver, CO 80216 Sent via Email to: brandon.maretteiRstate.co.us RE: Response to comments regarding DRMS Permit: M2022042 Dear Brandon Marette: This letter is in response to the Colorado Parks and Wildlife (CPW) comment letter submitted to Peter Hays, DRMS via email on October 24, 2022. The email shared comments on Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). Below you will find the comments you submitted, followed by Martin Marietta's response. Comments 1. This area has a well -documented Bald Eagle Nest and roosting area, which is immediately adjacent to one of the major parking lots for access on the Poudre Trail and the Poudre Learning Center. • Therefore, per our High Priority Habitat table, CPW recommends avoiding construction during the listed nesting (Dec 1 to July 31) and roosting seasons (Nov 15 to March 15). Response Martin Marietta is aware pf the locations of the eagle nests and roosting area and they will work with Mike Sherman as mining activity progresses. 2. There could be the potential for nesting Burrowing Owls. If prairie dog towns (active or inactive) are observed within the construction site, please avoid construction during the Burrowing Owl nesting season (March 15 to August 31). • If potential habitat (prairie dog towns) is observed, and the work needs to be conducted during the nesting season, please conduct a Burrowing Owl survey per this protocol. Response Martin Marietta will conduct a Burrowing Owl survey if the prairie dog towns on the site are disturbed between March 15 and August 31. 3. There could be Northern Leopard Frogs (and other Aquatic Native Species) in this stretch of the Poudre and associated tributaries, riparian areas, and adjacent uplands. • Therefore, please ensure there are more than sufficient stormwater BMPs to protect the Poudre from spills and/or sedimentation. Response Martin Marietta will utilize stormwater BMPs to protect the Cache la Poudre River. TETRA TECH page 1 of 2 DRMS Adequacy Review 1 Response- CPW March 1, 2023 Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH '7914nt,to- Pamela Franch Hora, AICP Senior Planner cc: Peter S. Hays, DRMS Jackson Davis, DNRjackson.davisPstate.co.us Mike Sherman, DNR mike.shermanWstate.co.us Boyd Wright, DNR boyd.wrightWstate.co.us Julie Mikulas, Martin Marietta Wrojects1Longmont87411117-87410061DocsVMMS\AdequacyReview1 Responses\DRAFT Adequacy Response CPW.docx TETRA TECH page 2 of 2 L..* TETRA TECH March 1, 2023 loana Comaniciu, P.E. Division of Water Resources 1313 Sherman Street, Room 821 Denver, CO 80203 Sent via Email to: Ioana.Comaniciu(Sstate.co.us RE: Response to Consideration of 112c Construction Materials Reclamation Permit Application Windsor East Mine, File No. M-2022-042 Operator: Martin Marietta Materials, Inc. - Julie Mikulas (970)-407-3631 Contact: Tetra Tech, Inc. - Pam Hora (720) 864-4507 W1/2 of Section 36, Twp 6 North, Rng 67 West, P.M., Weld County Division 1, Water District 2 Dear loana Comaniciu: This letter is in response to your letter from Division of Water Resources (DWR) Division 1 Office, Water District 2 letter dated October 24, 2022, commenting on Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). This letter shares your comments followed by Martin Marietta's responses. CONDITIONS FOR APPROVAL N The proposed operation will consume ground water by: © evaporation, W dust control, ❑x dewatering, ❑x water removed in the mined product, © reclamation: Prior to initiation of these uses of ground water, the applicant will need to obtain either a gravel pit or other type of well permit, as applicable. However, prior to obtaining a permit, an approved water supply plan or decreed plan for augmentation is required. Prior to approving a well permit, the applicant must conduct a field inspection of the site and document the locations of all wells within 600 feet of the permit area. The applicant must then obtain a waiver of objection from all well owners with wells within 600 feet of the permit area or request a hearing before the State Engineer. Response Acknowledged Comment The site is proposed to be dry mined. Dewatering trenches will be excavated around the perimeter of each mining area prior to the commencement of mining. Prior to the exposure or use of any groundwater at the site, the applicant must first obtain a well permit and a valid substitute water supply plan or decreed plan for augmentation. The applicant has indicated that they intend to obtain a substitute water supply plan for the site. Response Acknowledged Comment Water for dust control will be supplied using a 2,500 gallon water truck. The application indicates that water rights associated with the site will be used for dust control. The applicant will need to document that any water used for dust control purposes at the site is permitted or decreed for such use and be able to provide such documentation to this office upon request. TETRA TECH page 1 of 3 DRMS Adequacy Review 1 Response. DWR Div. 1, Water District 2 March 1, 2023 Response Acknowledged Comment Stormwater will be collected in the perimeter dewatering trenches and pumped into the Cache la Poudre River. If stormwater runoff is intercepted by this mining operation and is not diverted or captured in priority, it must be released to the stream system or infiltrate into the ground within 72 hours; otherwise the operator will need to make replacements for evaporation from the surface area of the intercepted stormwater. Response Acknowledged Comment As indicated above, Cell B is proposed to be reclaimed into a stormwater detention pond. The applicant should be aware that unless the structure can meet the requirements of a "storm water detention and infiltration facility" as defined in section 37-92-602(8), C.R.S., the structure may be subject to administration by this office. The applicant should review the Division of Water Resources' Administrative Statement Regarding the Management of Storm Water Detention Facilities and Post-Wildland Fire Facilities in Colorado, which can be found at https://dwr.colorado.gov/services/water-administration/rainwater-storm-water- graywater, to ensure that the notification, construction and operation of the proposed structure meets statutory and administrative requirements. The applicant is encouraged to use Colorado Stormwater Detention and Infiltration Facility Notification Portal, located at https://maperture.digitaldataservices.com/gvh/?viewer=cswdifto meet the notification requirements. Response Acknowledged Comment The Applicant has conducted a baseline groundwater assessment to assess potential impacts associated with the proposed sand and gravel mine. As part of the baseline groundwater assessment the applicant has constructed five monitoring wells. Monitoring well data will be used to identify changes in alluvial groundwater flow associated with mining and reclamation activities. According to the application, if the extent of groundwater changes due to mining or reclamation activities is determined to be a significant contributing factor that has or may create adverse impacts, the mining -associated impacts will be addressed to the satisfaction of the Division of Reclamation, Mining and Safety. Response Acknowledged Comment In certain areas of the South Platte River Basin, staff of DWR has observed groundwater problems that appear to be related to the lining of gravel pits located near streams, and in particular, these problems occur when multiple liners are located adjacent to each other. DWR requests that DMRS consider the siting and design of lined gravel pits to ensure that they will not individually, or cumulatively, result in impacts to the timing and quantity of groundwater flow from upgradient locations back to the stream system. In addition to impacts to property, such as flooding upgradient and reduced water levels downgradient of the liner, there are decrees of the court that specify the timing, quantity and amount of water depleted from the streams by wells and accreted to the stream through recharge operations. The installation of a gravel pit liner should not result in changes to the timing, location, and amount of such groundwater flow. Response Acknowledged TETRA TECH page 2 of 3 DRMS Adequacy Review 1 Response. DWR Div. 1, Water District 2 March 1, 2023 Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH -f�/IA�►Lrh Pamela Franch Hora, AICP Senior Planner cc: Peter Hays, DRMS Julie Mikulas, Martin Marietta WrojectsLongmont18741W7-8741006Pocs\DRMS\AdequacyReview1ResponsesIDRAFT Adequacy Response 1DWRl.docx TETRA TECH page 3 of 3 TETRA TECH March 1, 2023 JavierVargas-Johnson, Water Resources Engineer Division of Water Resources 1313 Sherman Street, Room 821 Denver, CO 80203 Sent via Email to: Javier.VargasJohnson(uistate.co.us RE: Response to Consideration of 112c Construction Materials Reclamation Permit Application Windsor East Mine, File No. M-2022-042 Operator: Martin Marietta Materials, Inc. - Julie Mikulas (970)-407-3631 Contact: Tetra Tech, Inc. - Pam Hora (720) 864-4507 W1/2 of Section 36, Twp 6 North, Rng 67 West, P.M., Weld County Division 1, Water District 3 Dear Javier Vargas -Johnson: This letter is in response to your letter from Division of Water Resources (DWR) Division 1 Office, Water District 3 letter dated October 28, 2022, commenting on Martin Marietta's 112c Permit Application for the Windsor East Mine (File No. M-2022-042). This letter shares your comments followed by Martin Marietta's responses. CONDITIONS FOR APPROVAL W The proposed operation will consume groundwater by: © evaporation, ❑x dust control, reclamation, © water removed in the mined product, O processing, O other. © Prior to initiation of these uses of groundwater, the applicant will need to obtain either a gravel pit or other type of well permit, as applicable. However, prior to obtaining a permit, an approved substitute water supply plan or decreed plan for augmentation is required. ® Any stormwater runoff intercepted by this operation that is not diverted or captured in priority must be released to the stream system within 72 hours; otherwise the operator will need to make replacements for evaporation. Response Acknowledged Comment The site is proposed to be dry mined. Dewatering trenches will be excavated around the perimeter of each mining area prior to the commencement of mining. Prior to the exposure or use of any groundwater at the site, the applicant must first obtain a well permit and a valid substitute water supply plan or decreed plan for augmentation. The applicant has indicated that they intend to obtain a substitute water supply plan for the site. Response Acknowledged Comment Water for dust control will be supplied using a 2,500 gallon water truck. The application indicates that water rights associated with the site will be used for dust control. The applicant will need to document that any water used for dust control purposes at the site is permitted or decreed for such use and be able to provide such documentation to this office upon request. Response Acknowledged TETRA TECH page 1 of 3 DRMS Adequacy Review 1 Response. DWR Div. 1, Water District 3 March 1, 2023 Comment Stormwater will be collected in the perimeter dewatering trenches and pumped into the Cache la Poudre River. If stormwater runoff is intercepted by this mining operation and is not diverted or captured in priority, it must be released to the stream system or infiltrate into the ground within 72 hours; otherwise the operator will need to make replacements for evaporation from the surface area of the intercepted stormwater. Response Acknowledged Comment As indicated above, Cell B is proposed to be reclaimed into a stormwater detention pond. The applicant should be aware that unless the structure can meet the requirements of a "storm water detention and infiltration facility" as defined in section 37-92-602(8), C.R.S., the structure may be subject to administration by this office. The applicant should review the Division of Water Resources' Administrative Statement Regarding the Management of Storm Water Detention Facilities and Post-Wildland Fire Facilities in Colorado, which can be found at https://dwr.colorado.gov/services/water-administration/rainwater-storm-water- graywater, to ensure that the notification, construction and operation of the proposed structure meets statutory and administrative requirements. The applicant is encouraged to use Colorado Stormwater Detention and Infiltration Facility Notification Portal, located at https://maperture.digitaldataservices.com/gvh/?viewer=cswdif to meet the notification requirements. Response Acknowledged Comment The Applicant has conducted a baseline groundwater assessment to assess potential impacts associated with the proposed sand and gravel mine. As part of the baseline groundwater assessment the applicant has constructed five monitoring wells. Monitoring well data will be used to identify changes in alluvial groundwater flow associated with mining and reclamation activities. According to the application, if the extent of groundwater changes due to mining or reclamation activities is determined to be a significant contributing factor that has or may create adverse impacts, the mining -associated impacts will be addressed to the satisfaction of the Division of Reclamation, Mining and Safety. Response Acknowledged Comment In certain areas of the South Platte River Basin, staff of DWR has observed groundwater problems that appear to be related to the lining of gravel pits located near streams, and in particular, these problems occur when multiple liners are located adjacent to each other. DWR requests that DMRS consider the siting and design of lined gravel pits to ensure that they will not individually, or cumulatively, result in impacts to the timing and quantity of groundwater flow from upgradient locations back to the stream system. In addition to impacts to property, such as flooding upgradient and reduced water levels downgradient of the liner, there are decrees of the court that specify the timing, quantity and amount of water depleted from the streams by wells and accreted to the stream through recharge operations. The installation of a gravel pit liner should not result in changes to the timing, location, and amount of such groundwater flow. Response Acknowledged TETRA TECH page 2 of 3 DRMS Adequacy Review 1 Response. DWR Div. 1, Water District 3 March 1, 2023 Thank you for your consideration. If you have any questions or need additional information, please let me know. Sincerely, TETRA TECH Pamela Franch Hora, AICP Senior Planner cc: Peter Hays, DRMS Julie Mikulas, Martin Marietta O:Wrojects1Longmont18741\117-87410061DocsIDRMsVAdequacyReview1 Responses1DRAFT Adequacy Response DWR2.docx TETRA TECH page 3 of 3 FS 0 aOFt%ANNIML �FL000 ELevnnaxe DEEf�FAEMwEO�. AS axowN Ox PRELIM INwT FEMA FIRM (MMCH 2J,10II3 LEVEES WNON CHANNELOFAWgIOV AREATHATMUBTI eG3AOETHE 1�. WTTHOUTCUNpIIATN£LYINCRFABINO mEYW' St5RFAt¢ ELE NATION LpPE T Wl OEBNW ED HNGHf,A8SH ) ONPSFLMINART FENA FW (MATCH 21, 1022) OIECT I MINING CONORONs� gREA OF i% ANNII.LLCHANCERWOP.'E FER =TECH amlpv MGV, x]te DRAB REVMEq CERTIFICATION PAMEU PPM HHOPA, MEP GRAVEL MINING APPLICANT/ OPERATOR: Mumry MARIETrn NwTERIae FO NORMTAFi HILL ROAD PT COLLINe. COLORADO 80511 SURFACE OWNERS: �55W LLc unaN ar P<t DENVER, C/JLORAD00oZ0e-1¢te EREFERTO6HEETSC2FORAO.WCENTPq Aro OVMEHe4NmIN10POFPERMRBOUNDARY, ADJACENT PROPERrvOYtNER INFORMATION WAB PRONpED BY WELD COUNTYRECDRDS. 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THENCE CCNRNU LNG NORM 00.10w"EAB' THENCE6DIIiH 03'3T'1Y EASiA p16TANCE THENCE 60Um &•A'Ea' t'.esF A pISTANCI THENCE THENCE MEET. 00•]021' WESTA DIBTAN THENCE MEET. 60'Jt'12' V"EeTADIOTNJ' E Ngini 00.00'00" WEST A CE PEP,. 00'JT81• PIPET PMMP E NORTH 80.50' W' EA6i A wBTANCE OF 1320.5 FEET: TIERCE NORM 00.5225• WESTAOLTTANCEOF 2J/E9 FEETTOn3E PwNTOF BEOWNINO.. PALO PESCNBEP PAPCEL OF LANG ...TAMP A TOTAL OF 9,MPMME EM. FT. CM 150;!!0 AGREE, MORE OR LEE6. O NORTH LINE A DISTANCE OF 1bT10 FEET; 2 B SS PROD: 11T-0TN000 DENT: OEVM: C-1 m.M6MwatMLn,wmNrsFaMNtm Ra lPemM L�r 'THEEXACTLOC4TONB aFTfEBE WATEW BEPNCELIHEBIe IINNNOWN, PIBORTOMININa T1EYKHLBE FlELO LOCATED. LINER pWE pe BHONN ON TH IB MPP, lHE LINER LMLL BE RELOC4TEO OW CELL o NiLL NOL BE MINED, LEGEND Windsor East Mine, Exhibit D - Mining Plan March 2023 1.0 GENERAL The Windsor East Mine property is located within the Town of Windsor in Weld County, Colorado. The Windsor East Mine site is on land owned by GWIP, LLC (GWIP). Martin Marietta Materials (Martin Marietta) has a lease to mine the GWIP property. The leased area is located within Parcel 08073600021, in Section 35 and 36, Township 6 North, Range 67 West of the 6th Prime Meridian. The geographic coordinates for the main entrance area are 40.450040° N, -104.851359° W. The property contains a significant commercial deposit of sand and gravel that is associated with the Cache la Poudre River. While the property is owned by GWIP, LLC, the mineral rights in the affected area are owned by the Colorado State Board of Land Commissioners. The Windsor East Mine is 150.3 acres. The permit boundary and affected area are the same for this application. Within the site, 90.1 acres of the land will be mined, and the remaining unmined acres will be used for overburden and topsoil stockpiles, offsets from existing structures and property lines. The permit boundary for the site was established to avoid impacting the riparian area along the Cache la Poudre River. In addition, all mining excavations will be set back a minimum of 200' from the riverbank and then backfilled to be no closer than 400' from the riverbank. Riverbank locations were located using GPS in June 2022 and the locations may vary over time. Offset distances are in accordance with the Technical Review Guidelines for Gravel Mining and Water Storage Activities, published by the Mile High Flood District in January 2013. A wetland area was identified on the site and mapped. The US Army Corps of Engineers has determined that this is non jurisdictional. Please see Exhibit J for the documentation. The proposed mining plan shows that Martin Marietta will mine through this area. A Biological Resources Technical Memorandum, produced by Pinyon Environmental, Inc., provided recommendations on state -listed or special concern species that have the potential to occur or be impacted by the mine. Martin Marietta will follow the recommendations provided by Pinyon. Please see Exhibit H for the documentation. There were oil and gas wells and flowlines through the middle of the property that were owned by Noble and DCP Midstream that are no longer used. Most of the wells have been plugged and abandoned per COGCC requirements. There is only one well left (State 8-36) for DCP to complete abandonment and the 150' radius will be maintained until the abandonment is complete. Martin Marietta has contacted DCP Midstream and found out that all the flowlines were properly abandoned in place and Martin Marietta can remove them as they mine. Martin Marietta will contact DCP Midstream as they encounter and remove these lines so that DCP can appropriately document their removal. There is also an oil and gas flowline running north and south along the east edge of the property. Martin Marietta is working with DCP Midstream to determine what needs to be done to cross this line with conveyor and equipment. It is estimated that the overburden will amount to approximately 676,000 cubic yards. Overburden exists to an average depth of approximately 5 feet over the entire site. All overburden and clay needed for the construction of the final reclamation will come from this site. The average depth of sand and gravel is 10 feet across the site and mining at the site is intended to progress down to bedrock. Deere & Ault Consultants, Inc. drilled 8 borings in 2017 for the property owner and Martin Marietta drilled 16 borings across the site in December 2019 with similar results. The results of these borings were used to understand the subsurface conditions across the Windsor East Mine area. Drilling logs indicate the general subsurface profile consists of approximately 3 to 9 feet of silty to clayey sand overburden, overlying approximately 6 to 17 feet of well graded gravel with varying amounts of sand and silt, overlying claystone bedrock. Groundwater was encountered at depths ranging from 4 to 7 feet in the most recent 2019 Martin Marietta OTETRA TECH Page 114 Windsor East Mine, Exhibit D — Mining Plan March 2023 borings. There is evidence that dewatering from the Parsons Mine to the east has increased the depth of the water table to 11-12 feet below the surface. The site will be mined in four phases, called out on the Exhibit C Mining Plan map as Cells A, B, C and D. These phases are neither representative of the maximum area of disturbance nor do they limit disturbance to a particular phase. Agricultural, industrial, residential, and mining uses surround the property. 2.0 METHODS OF MINING The typical mining procedure for all phases 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. The topsoil and overburden will be stripped with scrapers and stockpiled in the designated stockpile areas identified in Exhibit C. Overburden found on the site, will also be used to fill in the reclamation slopes. Overburden and topsoil reserved for reclamation will be vegetated and stabilized in accordance with Rule 3.1.9(1). Mining will expose groundwater (for details on the timing, please see Section 2.1 of Exhibit G).Prior to mining, a dewatering trench will be constructed around the perimeter of each phase. A sump hole will be created at the lowest point of each dewatering trench. The sump holes and dewatering trenches will allow sediment to settle before the water is pumped to the Cache Ia Poudre River using a dewatering pump in accordance with Colorado/NPDES discharge permit regulations. Pipes will be used to transport the water from the mine to the Cache Ia Poudre River. The location of the discharge pipes will be adjusted throughout the mining process. When the mined alluvium is sufficiently dry, front-end loaders will excavate the material. The high wall of the mine cells will not exceed a 1:1 slope. All mined material will be deposited on conveyors which will transport the material to Martin Marietta's existing plant site at the Parsons Mine (M-2009-082), directly east of Windsor East. No materials processing will occur at the Windsor East Mine site. Surface water within the mine areas will drain internally. 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. Water rights associated with the site will be used for dust control operations along the roads, stockpiles, transport of material 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 will be used to mine the site. 3.0 OVERBURDEN Topsoil and overburden will be stripped with scrapers or a dozer and placed separately in temporary stockpiles within the permit area limits. The topsoil will be segregated and stored separately from the overburden material as required by Rule 3.1.9(1). The stockpiles will have an average height of 8 feet tall; they will have maximum 3:1 (horizontal:vertical) side slopes. The topsoil stockpiles will be protected from wind and water erosion by vegetative cover (see the Seed Mix for Upland Areas found in Exhibit E). The stockpiles will be broadcast seeded and incorporated into the weed control program. Weed control consists of chemical treatments as needed in the applicable fall and spring seasons. Topsoil and overburden stockpiles reserved for reclamation will be vegetated and stabilized in accordance with Rule 3.1.9(1). The overburden stockpiles will be continuously rotating. Initially, a portion of a phase will be stripped, and the overburden stockpiled temporarily within the permit boundaries. Once the deposit has been mined from the stripped portion, the temporary stockpile will be removed and used for reclamation. The remaining portion of the cell will then be stripped, and the overburden will be stockpiled on the mine floor or placed immediately in the reclamation slope. No excess overburden is anticipated for this site. OTETRA TECH Page 214 Windsor East Mine, Exhibit D — Mining Plan March 2023 4.0 COMMODITIES TO BE MINED The primary commodity to be mined will be aggregate and a secondary commodity will be gold. Martin Marietta will supply local, county, and state governments, as well as private industry with aggregate from this facility. If gold is mined it will be used for commercial purposes. 5.0 OFFSETS Tetra Tech prepared a Slope Stability Analysis to ensure that all existing structures will be protected based on the proposed reclamation slopes. 6.0 ROADS AND CONVEYORS Preparation for mining for each phase will include a 15' wide gravel access road around the perimeter of the cell. Any additional short-term haul access will be constructed with 6" of native sand and gravel from the floor of the mine. These gravel roads will be removed and reclaimed as mining and reclamation is completed for each phase. These areas have been included in the permitted acreage. All the material will be transported via conveyor from the mining cells to Martin Marietta's Parsons Mine to the east for processing. The conveyor is set on concrete block or frames. The main line will run down the future Crossroads path and feeders will be dropped into each phase we are mining and then removed before reclamation. All areas affected by the conveyors will be re-topsoiled and seeded to restore ground to the original condition. A 10.5' wide existing road that currently connects to WCR 23 will be utilized to provide street access to this site. The location of this existing road is shown on Exhibit C, Pre -Mining Plan. It is located northwest of cell B. 7.0 MINE SCHEDULE Depending on market conditions, the Windsor East Mine operation will process approximately 450,000 - 500,000 tons of aggregate per year. At this rate, Martin Marietta anticipates mining and reclaiming the site in approximately 8 years (about 6 years to mine and another 2 years to complete reclamation and get grasses to establish). The table outlines the anticipated mine schedule by phase. As previously stated, this schedule is just an estimate since the rate of mining and overall life of the mine is dependent upon demand and market conditions. Phase Mine Area (in acres) l Projected Time to Mine (in years) Cell A 35.3 2± Cell B 17.7 1± Cell C 32.3 2± Cell D 4.8 1± 8.0 PHASE OVERVIEW The four cells in Windsor East will be mined as explained below. The following is a detailed description of Martin Marietta's plan to mine the four cells that are proposed along with an explanation of how the topsoil and overburden will be handled. Please refer to Exhibit C-3 for the locations of each mining cell, topsoil stockpile (TS#) and overburden stockpile (OB#). OTETRA TECH Page 304 Windsor East Mine, Exhibit D — Mining Plan March 2023 1. The topsoil from Cell A will be stripped and placed on the north property line in stockpile TS1. Overburden from Cell A will be stockpiled in OB1. 2. Cell A will then be mined. 3. Topsoil from Cells B and C will be stripped and placed in stockpiles TS1, TS2, and TS3. Overburden from Cell B will remain in place and overburden from Cell C will be used to reclaim the slopes of Cell A. Any excess overburden from Cell B will be placed in stockpile OB1 or in the overburden overflow area on top of Cell B. 4. Cell C will be the second cell mined. The slopes of Cell C will be concurrently reclaimed using overburden from stockpiles OB1 and the overburden overflow area on top of Cell B. 5. Cell D topsoil will be stripped and used in reclamation of Cells A and C. Overburden from Cell D will be used in the reclamation of Cell C. Any excess overburden from Cell D will be placed in stockpile OB2. 6. Cell D will then be mined. It will then be reclaimed by backfilling it with overburden from the overburden overflow area on top of Cell B including the overburden originally left behind in Cell B. 7. Cell B will be the last cell mined, and it will be backfilled with the remaining overburden from stockpile OB1. 8. The topsoil from TS1, TS2 and TS3 will then be used to complete reclamation of Cells B and C as well as the edges of Cells A and C. 9.0 EARTHMOVING Earthmoving is performed using a combination of mobile mining equipment including, but not limited to loaders, dozers, scrapers, backhoes, water trucks, diesel powered generators, and pumps. OTETRA TECH Page 414 Windsor East Mine, Exhibit E — Reclamation Plan March 2023 EXHIBIT E - RECLAMATION PLAN 1.0 DESIGN INTENT This site will be mined and reclaimed to create two water storage ponds that the landowner, GWIP will own and use for water storage. Water stored in the ponds will be used by GWIP to satisfy augmentation requirements. Currently, GWIP leases water from the Town of Windsor to satisfy some augmentation requirements. So, upon completion of the reservoirs, GWIP will no longer need to lease water from Windsor to meet this requirement. Two lined water storage reservoirs surrounded by revegetated upland areas will be created by the mining and reclamation process. Native and adaptive plantings and ground covers will be used to restore and enhance all areas disturbed by mining activities that will not be within a lined water storage cell. This reclamation plan was developed based on: A thorough evaluation of the environmental resources and existing conditions on and adjacent to 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 Windsor, the Colorado Division of Mining, Reclamation and Safety and other applicable local, State and Federal agencies. Key considerations include the following: The permit boundary on the south was placed outside of the Cache la Poudre riparian corridor to protect the area. All wetlands on the site were located and delineated. The one wetland found is being reviewed by the Corps of Engineers to determine if it is jurisdictional or not. If found to be jurisdictional, the mining plan will be adjusted to protect the wetland from disturbance. The 200' setback from the river will be clearly marked in the field and best management practices will be used as necessary to implement the CDPHE Storm Water Management Plan for the site. Maintenance activities on the site will also include a comprehensive Weed Management Plan (see attached) to limit the spread of invasive species into the riparian areas and wetlands. Much needed water storage reservoirs will be created on the site. The reservoirs will be lined with compacted material acceptable to construct liners that are found on the site. Five groundwater monitoring wells have been installed to establish pre -mining baseline water levels along with the Parsons Mine (M-2009-082) monitoring wells. The wells will be used to monitor effects from mining and provide information for mitigation of potential impacts on groundwater levels and riparian vegetation, as necessary. If levels drop below seasonal levels, dewatering water will be diverted to the areas to sustain existing vegetation to limit impacts during mining. Details of the monitoring and mitigation plans are provided in Exhibit G. 2.0 POST -MINING LAND USE The post -mining land use, as proposed in this Reclamation Plan consists of water storage ponds surrounded by upland vegetation. All disturbed areas will be vegetated as appropriate with a native seed mix, as recommended by the Soil Conservation Service (recommended seed mixes below). These uses are compatible with the surrounding land uses and with the Town of Windsor planning goals. TETRA TECH Page 1 j4 Windsor East Mine, Exhibit E — Reclamation Plan March 2023 Martin Marietta will concurrently mine and reclaim this site. Reclamation, including regrading and seeding, will be completed within two to five years following the completion of mining or filling operations for each phase. 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. 3.0 RECLAMATION MEASURES - MATERIAL HANDLING Site reclamation measures are illustrated in Exhibit F. Reclamation of the site will include 2 water storage ponds (54.77 acres) and 35.43 acres of upland vegetation. The ponds will be reclaimed as water storage ponds. All mine walls will be re -graded with overburden material to create a compacted liner. A cross-section of the proposed design for the liner is below. EXAMPLE OF CLAY LINER DESIGN Full design of each liner will be completed by a registered professional engineer as mining of the cell is completed based on soil analysis, site conditions and DRMS slope stability requirements. Full design will be submitted to the DRMS as a Technical Revision to M-2022-042. TYPICAL CROSS SECTION Q 1G 20 SCALE IN FEET * Slope design to be determined by PE based on soil analysis, site conditions and DRMS slope stability requirements A copy of the clay liner design will be submitted to the Division for review and approval, through a Technical Revision process, prior to construction of the liner. Slopes above the post -mine high water level will be 3:1 and slopes below the post -mine high water level will not exceed 3:1. Topsoil will be spread to a minimum depth of 6" over the surface of all areas outside the water storage basins that are to be revegetated as uplands. Scrapers will be used to place the backfilled material. Using scrapers to layer the lifts at a maximum 3:1 slope ensures a stable configuration. Reclamation quantities and costs are summarized in Exhibit L. TETRA TECH Page 214 Windsor East Mine, Exhibit E — Reclamation Plan March 2023 4.0 WATER Overburden and mine materials will be inert and impacts to local surface water or groundwater quality are not anticipated to occur because of mining activities. Martin Marietta Materials, 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 adjacent Cache la Poudre River and riparian vegetation. Cell B will be backfilled above the water table leaving a 5 -foot depression as defined in our lease. No stormwater will be directed to this depression, but any stormwater collected will dissipate into the ground. GWIP, LLC, the landowner, intends to use this depression as part of their stormwater detention when they develop on adjacent land and will work with Town of Windsor on their development once our reclamation permit is released. Martin Marietta is not required to install any structures as part of the depression including but not limited to headwalls, outlets, piping and forebays. 5.0 WILDLIFE Presently, the area is used for general agriculture. There is significant habitat for many wildlife species along the river corridor which is outside our permit boundary. Please see Exhibit H (Wildlife Information) for more information pertaining to the recommendations and conclusions from the environmental report. 6.0 TOPSOILING Topsoils in the proposed mine areas are predominantly Aquoll and Aquents, Ellicott, Colombo clay loam, Kim loam, and Nunn clay loam. All suitable soil material will be salvaged for topsoil replacement. Topsoil will be replaced, where required, in reclaimed areas at a depth of a minimum of 6 inches. The topsoil will be segregated and stored separately from the overburden material as required by Rule 3.1.9(1). Sufficient topsoil will be stockpiled within each phase to reclaim all disturbed areas. The mine plan map depicts the location and configuration of the berms. The berms will be protected from wind and water erosion by vegetative cover if in place for more than 180 days and will be vegetated depending on the seeding "window" parameters for dryland grass, which are typically between September and April. 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. 7.0 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. The above procedures may be modified as conditions dictate. 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. OTETRA TECH Page 314 Windsor East Mine, Exhibit E — Reclamation Plan March 2023 8.0 WEED MANAGEMENT PLAN A weed management program will be undertaken to control noxious and invasive plant species and to replace those species with native and naturalized vegetation. Canada thistle (Cirsium arvense) and leafy spurge (Euphorbia esula) will be treated by a combination of mowing at regular intervals and herbicides used at the appropriate times and applications levels. Please see the attached Weed Management Plan. 9.0 SEED MIX FOR UPLAND AREAS C©rl m tc Name e y .. io4 .l, .. JG� `n tt n . inn: Western Wheatgrass Agropyron smithii Arriba 17.0% 1.74 Sideoats Grama Bouteloua curtipendia Butte 17.5% 1.80 Mountain Brome Bromus marginatus Bromar 17.0 % 1.74 Prairie Sandreed Calamovilfa longifolia Goshen 1.0% 0.48 Switchgrass Panicum virgatum Pathfinder 7.0% 0.67 Alkali Sacaton Sporobolus airoides 1.0% 0.10 Needle and Thread Stipa comata 13.0% 1.29 Northern Sweetvetch Hedysarum boreale Timp. 10.0% 1.02 Rocky Mountain Penstemon Penstemon strictus Bandera 5.0% 0.46 Scarlet Globemallow Sphaeralcea coccinea ARS2936 3.0% 0.26 Prairie Wildrose Rosa Arkansana 8.5% 0.87 Total lbs/ac l 1 100% 10.43 totes: 1. Pure Live Seed pounds per acre; rates shown are for drill seeding; double rates for broadcast seeding. 2. All upland areas will be mulched with 1 ton of certified weed free straw per acre. Mulch shall be applied within 24 hours of seeding and crimped in place. OTETRA TECH Page 414 SEED MIX AND SEED MIX NOTES: 1. ALL SUESRRRIONS WILLDEIFAMINED IN CONSULTATI E%PERT6, AND APPEOPRIATETOTHEREGION AND Z FIG�H EW4TERIMEI9 APPRp%IMATE EASED aN ANt owft0. ] uRIN6T1E FlRsl'FAVOR �EpING WILL eEDIXiE EEMEENHEPTEMEERANI HEATHER cpNOiT10NS REDUIPESEEDING OUT6101 GMs6ESARE TO EEEHTABusHEp ABOVETHEHH]H-WATEI]UNE ON SERVOIRBIOESLOPES. NEWeEEp6PIANTEDINroACOVERCROP,OR CERTIFIED NEERFREE 61RAW CRIMPED INro TOP801L. AERATION WTM MnTER4,E, SAFETY IHFORMEp PAMELA EN.. HOPq. NON ONTE GRAVEL MINING APPLICANT/ OPERATOR: MARTIN M4RIETTw L1glERHEs tBJO NORTH TAFT HILL ROAD FOgT CO W Na,.CO10RA00 m41 SURFACE OWNERS: ON1LLALLc EN COInR400 EP�imE EXISTING VEGETATION: RTeYPINYON B-IVIaorvMENFN., INc. PRovIDEOTHATTHE PRaECTAREA Is cuRRENTLY LBED PR IPNLo)ANp WETITANp AETu THEEA6TN FTHESITEINPtFwsEs EIXHBRJIIFORM pE VEG ONINFORMATION. SURVEY INFORMATION: J.EO'ALUMINUM CAPBEFIN CIXICRETESFAM19E➢•KING 6URVEYOR9 YNN�KOWil42sT iBeT', IN THE vICINRYt'ri ,VACORNEROFeECTIWm,'RN,RWW, ATIHENE6TENTRANCE TOKODAKROAD, JEN.OFTHECENTFA LINEOFKOpAK ROADAN010.0'E.OF THE 6TOP fiIGN. FIEVATION • {i5{.T.1 FEET PIAVp Ism OAiuFq 1u. ==eM1AHEMOSREAT NESTERNALTNN6P& LAND TIRE SURVEY pATEp FLOOD HAZARD INFORMATION: IAIN 6NFORMATION I6cMoIMZN4REYFLODOINSON OF1NI5 LANo UE6 WI'IHMZONEAE PECML FLOOD NAIAIROAREtRINUNDATEDs'(IHE I%ANNUAl CHPNCE RaOO)AND REGULATORY RECLAMATION AREA ACREAGE TABLE: WATER 6TIXiAGE EE6ENVOIR COMMON NAME NEE.. WHFA .. eIpEMTS GPAMA NOWT. EECME PgnIRIE84NDPEEO BWTCHGMs9 ...NON NEE. !MOTH.. NORTHERN 6NEETVETCH SCIENTIFIC NAME AGROPYEONONOTHII VARIETY % OF MIX PLS APPLICATION RATE (LBS/AC) GUNMEN. Mus MgaolNAnw ON...FA LONG.. PANICUM VIRGATUM ENE, ...TN EROME PATHFINDER 11,6% ....UM BFEALE ...TEN. NMI.. EANDE0.n LFFOLOSEMALLOW PRAIRIE LMI➢R0.5E TOTAL LBS/AC R084AAKANSANA AR8JEE0 10096 SHEET INDEX: EYHIEITF RECLAMATION PLWEAST 61 ENOTES PERMIT BOUNDARY AND AFFECTED AREA LEGAL DESCRIPTION: A PARCEL OF LAND, LOCA1Ep INTHE WEST N4LF (W1IM oFBECTION THIRTYSIX(JB)ANDTHE NORTHEA61'g11ARTER OF Xtt..sENEN NEfiTI pTWR. 61%m eniN)c14L MER�pIAM(BTH HI.M.)�]co�NTY pF VWI,p, siATEOF pO)�panLO, MppE ARI'I LAgLYDESCmEEp EOFBApnsECTION90 eeE.emN NORTIm•30'01'EASTHITHPL. EEARwOS CONTAI NNEp HEREw REIATNE THERETO. PgNTOFBEeINNINp.. EpE6CRIEEDPARCELOF LANDGONTNNSATOTAIF 0,5HA0.09O. FT.F 150310AGREE,VZEs LE66AN01S USIf�TTOANYIXISTNO Ew6EMEN18ANp RIGMS OFNt4Y OF REcgip pRABMOW IXi6TINGON 6AI0OE6cRIEEp PPA FlANO. ORVM: F-1 PH Windsor East Mine, Exhibit G — Water Information March 2023 EXHIBIT G: WATER INFORMATION This Exhibit addresses the hydrologic conditions at the Windsor East Mine located in Section 36, Township 6 North, Range 67 West of the 6th Principal Meridian, Town of Windsor, Colorado (See Figure G-1), The Exhibit documents the depth and direction of groundwater flow, the nature of the subsurface geologic materials through which it flows (Figure G-2), any interactions with streams, lakes, canals or other surface water bodies in the area and the potential impacts to surrounding water users due to mining impacts. The information in this Section is intended to satisfy the requirements outlined in Sections 3.1.6, 6.3.3, 6.3.4, and 6.4.7 of the Colorado Mined Land Reclamation Board's Construction Material Rules and Regulations. Section 3.1.6 (1) Hydrology and Water Quality: 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, including, but not limited to: (a) compliance with applicable Colorado water laws and regulations governing injury to existing water rights; (b) compliance with applicable federal and Colorado water quality laws and regulations, including statewide water quality standards and site -specific classifications and standards adopted by the Water Quality Control Commission; (c) compliance with applicable federal and Colorado dredge and fill requirements; and (d) removing temporary or large siltation structures from drainage ways after disturbed areas are revegetated and stabilized, if required by the Reclamation Plan. Section 6.4.7 (1) If the operation is not expected to directly affect surface or groundwater systems, a statement of that expectation shall be submitted. This site is directly adjacent to the Cache Ia Poudre River. The Cache Ia Poudre River will be utilized for the discharge of dewatering water from each of the proposed mine cells. The presence of the river has the collateral benefit of mitigating groundwater drawdowns and associated impacts to wells east of the Site. (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. Please see Exhibit C Pre -Mining Maps for the location of all 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 OTETRA TECH Page 111 Windsor East Mine, Exhibit G — Water Information March 2023 The Windsor East site is underlain by two aquifers: • The valley -fill deposits of the Lower Cache la Poudre River. o described in: Hershey, L.A. and PA. Schneider, 1972. "Geologic Map of the Lower Cache la Poudre River Basin, North-Central Colorado", USGS Miscellaneous Geologic Investigations Map I-687. (See Figure G-2) • The Fox Hills Sandstone o described in: Robson, S.G. 1989, "Alluvial and Bedrock Aquifers of the Denver basin — Eastern Colorado's Dual Ground -Water Resource", USGS Water -Supply Paper 2302 (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. The geologic conceptual model of the subsurface and groundwater was developed from the geologic map for the area and the boring logs associated with the installation of the monitoring well network at the Windsor East site and the Parsons Mine site located to the east (Figure G-3). Based on water levels measured in these wells, a groundwater level elevation map was developed (Figure G-5). Following removal and stockpiling of topsoil, each of the four cells will be dewatered and mined. Sand and gravel will be extracted using the "dry" mining method in which the water table is lowered to allow mining to be performed under drained conditions. To lower the water table, local dewatering is conducted using a perimeter drain constructed around each planned mining cell. The dewatering system would discharge to the Cache la Poudre River. Dewatering of the mine would lower the groundwater levels to a limited extent in the surrounding alluvial aquifer and will not impact the underlying Fox Hills Sandstone aquifer. Effects on groundwater levels are projected to be limited in extent due to natural and manmade hydrologic and hydrogeologic characteristics and boundaries, principally including the transmissive nature of the alluvial aquifer, the Cache la Poudre River, and the mining operation. Figure G-6 illustrates the resulting changes to groundwater flow directions during mining and after reclamation. The available gravel resource is anticipated to be mined for approximately 6 years; however, the rate of mining and overall life of the mine is dependent upon demand and market conditions. All material mined at Windsor East will be conveyed to Martin Marietta's adjacent Parsons Mine site for processing at the existing plant on that site. Upon completion of mining, the reclamation plan for the mine includes the placement of compacted clay embankment liners in Mining cells A and C, while cells B and D will be backfilled with non -economic grade alluvium including topsoil, sands, and fine gravel. These cells will thereby be converted to sealed water storage reservoirs, which will be owned and used by GWIP, LLC, the landowner of the Windsor East Mine site. Exhibit D: Pre -Mining and Mining Plan shows the location of the Affected Area and proposed mining cells. Changes to the hydrologic balance within the Affected Area will be limited to the localized dewatering associated with the excavation of the mine cells, and the minor alteration of the existing groundwater flow patterns due to the subsequent installation of compacted clay embankment liners during reclamation. Figures G-5 and G-6 show the mine cells and conceptual groundwater flows before and after the installation of the compacted clay liners. 1.1 HISTORIC USE The Windsor East property has historically been used for agriculture. The adjacent neighbors include Martin Marietta's Parsons Mine site to the east, agricultural land with a few residences to the north and west, and the Cache la Poudre River to the south. Based on well registration, land use besides agriculture within two miles of the site has included Eastman Kodak to the west and northwest, Front Range Energy to the northwest of the site, Joseph Energy to the northwest of the site, and Hensel Phelps Construction to the northwest of the site. OTETRA TECH Page 2111 Windsor East Mine, Exhibit G — Water Information March 2023 1.2 HYDROGEOLOGIC SETTING 1.2.1 Geology The geology mapped at land surface beneath the site consists of quaternary age valley -fill deposits comprised of sand, silt, and gravel primarily (Figure G-2). The areas of higher elevation around the site are typically comprised of quaternary terrace deposits. Boring logs from installation of monitoring wells immediately east of the property were reviewed for details on the site geology. The Parsons sand and gravel mine has 12 monitoring wells on the property, including MW -12 which is the nearest to the Windsor East property, located between the Parsons property and the Windsor East property (Figure G-3). The boring logs generally indicate that the geology consists of a 10-30 ft thick layer of unconsolidated alluvial sediments overlying siltstone bedrock. The upper 4-14 feet of the alluvial sediments are typically finer -grained silts and clays and may be only partially saturated in many locations. The lower 4-20 feet of the alluvium consists of sands and gravels which are expected to be highly transmissive of shallow groundwater. The shallow bedrock of the Fox Hills Sandstone consists of weathered, consolidated sedimentary rock varying from claystone to siltstone as observed in the boreholes advanced on the Parsons mine property to the east. In comparison to the alluvium, the weathered bedrock is expected to be several orders of magnitude less transmissive due to the consolidated, finer -grained properties. Bedrock was encountered in the boreholes advanced at the Windsor East mine property between 15 and 22 ft below ground surface (bgs), and 13ft bgs in the nearest Parsons Mine borehole (Parson MW -12). 1.2.2 Groundwater Groundwater at the site represents a combination of water that flows through the high -permeability valley -fill alluvial deposits parallel to the Cache la Poudre River and water that infiltrates in the surrounding higher -elevation recharge areas to the north and south of the river, typically associated with the agricultural fields that dominate the land use of the area. Infiltrating water in these areas of higher elevation drains at the lower -lying erosional valleys formed by streams and rivers of the area, resulting in flow patterns that resemble a muted form of the land surface topography. The erosional valleys are typically underlain by the higher -permeability sands and gravels deposited by historic flood events and form channeled zones through which groundwater can flow more rapidly. South of the Windsor East property, the Cache la Poudre River is the surface -water feature for local groundwater discharge. Within several hundred feet of the river, groundwater flows in a direction that is near parallel to the river due to the constant interaction with the river stage within the porous sands and gravels. As a result, while groundwater beneath the site is typically slightly higher than that of the river and flows toward the river, the flow direction of groundwater flow is generally parallel to the Cache la Poudre River from west to east, at close proximity (Figure G-5). Some minor component of upward groundwater flow from the deeper bedrock may occur, but this is likely to be negligible compared to the influence of the river and the underflow within the valley -fill alluvium. The direction of regional shallow groundwater flow is therefore toward the southeast but changing to a near easterly direction near the river. Based on water -level measurements in the monitoring wells installed at the Windsor East mine property, the water table is approximately 8-11 feet below land surface. 1.3 EXISTING AND PLANNED WELLS 1.3.1 Existing Monitoring Wells A network of monitoring wells was installed in 2010 to characterize the groundwater conditions at the Parsons mine east of the Windsor East property (Figure G-3). The boreholes for the wells were drilled to the bedrock contact and the wells were constructed using 8-10 foot screened intervals between the water table and the bedrock contact. These wells generally show the direction of groundwater flow in an easterly direction, in equilibrium with the river water elevations, although subject to the influence of the Parsons mine cell dewatering. OTETRA TECH Page 3(11 Windsor East Mine, Exhibit G — Water Information March 2023 1.3.2 Well Inventory In May 2022, a well inventory of the Affected Area and adjacent areas was conducted to identify wells near the project. The inventory included a search of the State of Colorado Office of the State Engineer database of wells located within'/ mile of the Affected Area (Table 1). The well inventory identified 25 constructed wells within 1/2 mile of the Affected Area. Figure G-4 enclosed shows the Affected Area and the constructed well locations on file with the Colorado Division of Water Resources. Wells located within 600 feet of the Lease Boundary The well inventory identified two wells completed in the alluvial aquifer within 600 feet of the lease -area boundary. The first is a monitoring well (Parsons MW -12) owned by Martin Marietta (permit # 280593) associated with the Parsons mine immediately to the east of the Windsor East property. Bedrock was encountered at 13 ft bgs and water was observed at approximately 6-8 ft bgs. The second is a monitoring well owned by Hall -Irwin Corporation (permit # 277000). It was constructed in 2007 and was screened from 4 to 15 ft bgs. Bedrock was encountered at 13 ft bgs and water was observed at approximately 2 ft bgs in 2007. Monitoring holes and wells are not a concern for dewatering impacts because neither are allowed to serve as pumped sources of water. Water supply wells located within'/z mile of the Lease Boundary In addition to the wells identified within 600 feet of the lease boundary, the well inventory identified two residential wells, eight monitoring/observation wells, three monitoring holes, and one general purpose well completed in the alluvial aquifer within '/ mile of the lease -area boundary. Appendix G-5 provides a letter from GWIP LLC regarding the status of wells 89706-A, 113762—A, and 1472 -R -R. Permit number 89706-A Domestic/Residential well (89706-A) is registered to Brett T and Mary K Lauer. It was constructed in 1977 to a depth of 32 feet. It is located slightly more than 600 feet distance from the lease boundary on the northwest corner, and approximately 1,060 feet northwest from the nearest planned mining cell. The well is 5 -inch diameter PVC, screened from 17 to 32 ft bgs, and was equipped with a pump capable of 30 gpm. The driller's log indicates that water was encountered at 12 feet bgs in 1977. A 6 -hr pumping test conducted in 1977 resulted in sustained pumping of 20 gpm and a pumping water level of 27 ft bgs (15 feet of drawdown, a specific capacity of 1.33 gpm/ft). Bedrock was observed at 27 ft bgs. The parcel that this well sits on is owned by GWIP LLC, the property owner for this reclamation permit application. Permit number 113762--A Domestic well (113762--A) is registered to M WaterCo LLC, although originally to Harold Long and Sons. It was constructed in 1980 to a depth of 25 feet. Water was noted at 12 ft bgs and bedrock was encountered at 20 ft bgs. A sustained pumping test of 30 gpm for 2 hours was conducted in 1980 with no recorded drawdown. It is located 1500 to 2000 feet distance from the lease boundary on the north side. A registered domestic well with a similar permit number (113762-) is associated with Harold Long and Sons Inc. The date of construction was not recorded, but the well inventory indicates that it was drilled to a depth of 30 feet, encountering bedrock at 20 ft bgs. This well shares nearly identical location and construction information (and permit number) with the well registered to M WaterCo LLC and seems to be the same well. The parcel that this well sits on is owned by GWIP LLC, the property owner for this reclamation permit application. Permit number 1472 -R -R General Purpose well (1472 -R -R) is registered to West Weld Ag Investors. This well was originally drilled for Allen Lamb with permit number 1472 before 1957 and listed as an irrigation well. It was replaced by well 1472-R at an unknown date to a depth of 15 ft bgs, with a 40 ft by 60 ft sump from which water was pumped at approximately 500 gpm. A permit application was received in 1981 to replace well 1472-R with a new irrigation well by West Weld Ag Investors with a proposed maximum pumping rate of 500 gpm and a planned depth of 50 ft. The registered UTM coordinates for the well indicate that it is located several hundred feet south of the Cache la Poudre river, but the description in the permit indicates that it is located 3,300 ft south of the northern edge of OTETRA TECH Page 4111 Windsor East Mine, Exhibit G — Water Information March 2023 section 35 and 1,300 ft west of the eastern edge of section 35, and therefore may actually be located just north of the river near UTM 512260 E, 4476810 N. This location is approximately 1,200-1,300 ft west of the southwestern corner of the lease boundary, and approximately 1,500 ft from the nearest planned mining cell. A loop of the Cache la Poudre River extends between the lease area and the likely location for the well. Based on both a field and records investigation, the well listed at 1472 -R -R is believed to have been located near the irrigation center pivot, and abandoned at some time in the past. The parcel that this well sits on is owned by GWIP LLC, the property owner for this reclamation permit application. Monitoring Wells on the Adjacent Parsons Mine Property Monitoring wells installed as part of the Parsons Mine operations were considered as part of this permit application. Twelve of the fourteen wells were installed in 2010 and the other two were installed more recently. Table 2 includes construction details and depth -to -water information. Measuring point elevations were surveyed on December 15, 2022, to the nearest 0.01 ft elevation. Appendix G-2 provides water levels measured over time for the Parsons Mine monitoring wells. 1.3.3 Site Monitoring Wells Martin Marietta installed five monitoring wells (Figure G-3) in August 2022 to support the monitoring plan associated with the project, documenting the groundwater conditions before initiation of mining, during mining, and after mining is complete. Through the well monitoring program, the wells will serve as points at which water levels will be measured and water quality samples collected. The boreholes for each of the wells were advanced until bedrock was encountered. Lithologic logs documenting the valley -fill sediments observed and the bedrock during drilling were recorded. The monitoring wells were constructed of two-inch Schedule 40 PVC casing and screen. Silica sand was placed from approximately two feet above the top of the screen to the bottom of the borehole (bedrock). Above the silica sand, a bentonite seal was placed in the borehole annulus to restrict infiltration of surface water. Each of the monitoring wells was finished at the surface with a locking, aboveground, steel protective casing set in concrete. Table 3 provides additional details on the monitoring well installations. Appendix G-1 presents borehole logs and well completion details for the monitoring wells. 1.4 HISTORIC AND FUTURE GROUNDWATER LEVELS Monitoring wells established at the Windsor East site in August 2022 were used to collect groundwater elevation data. This set of water level data was supplemented by water level data collected from monitoring wells on the adjacent Parsons Mine site located east of the Windsor East property. Water level data measured for the wells are included in Tables 2 and 3. Depth to water at the Windsor East site varies from 7.9 to 10.4 ft below the top of the well casing, corresponding to a range of water level elevation from 4732.14 at MW -06 to 4717.44 at MW -11. Figure G-5 presents the general direction of groundwater flow (southeast). Since 2010, regular groundwater measurements have been collected from the 14 monitoring wells around Martin Marietta's Parsons Mine site. These wells shall hereafter be referred to as the Parsons Well Network, and are numbered MW -1 through MW -14. Appendix G-2 shows the variation in water level measurements from monitoring wells MW -1 to MW -12. Water levels measured in the Parsons well network vary from 4730 feet at MW -5 to 4690 feet above mean sea level (amsl) at MW -1 where the effects of dewatering are visible in late 2021 through 2022. Water levels are seasonally at their highest elevations in August or September following the irrigation season, and typically at their lowest elevations in February to March when irrigation has been suspended for the longest period of time. The water level at MW -12 before initiation of local dewatering in 2019 ranged from 5.8 to 7.8 ft bgs (4720.5 to 4722 ft amsl), then dropped to an average of 11.3 ft bgs (4716.7 ft amsl), a drawdown of approximately 4.6 ft. This monitoring well is located approximately 100 feet from the dewatering trench of the nearest active mining cell at the Parsons Mine, and the 4.6 -foot change in water levels experienced at the Parsons Mine is expected to be representative of the drawdown that will be associated with dewatering of the mining cells at the Windsor East site. Based on observed water levels at the Windsor East and Parsons sites, dewatering will lower water levels to within 2 feet of the top of bedrock in the immediate vicinity of each mining cell. The lowered groundwater effects TETRA TECH Page 5111 Windsor East Mine, Exhibit G — Water Information March 2023 will be transmitted horizontally by the gravel aquifer, reducing water levels in the surrounding area as a "cone of depression" forms around the mining cell. During mining, water in the area will flow radially toward the dewatered cells, where it will be removed using the dewatering trench drainage system and discharged into the river. Following mining, each cell will be lined to form a hydraulically isolated reservoir. The effect of the clay liner on the groundwater within the aquifer will be the formation of a hydraulic mound upgradient of the cell where water levels will be several feet higher than under pre -mining conditions. Downgradient of the cell, the groundwater levels will be several feet lower due to a "shadow effect" behind the reservoir. These changes in groundwater levels due to the clay -lined cells are expected to have minimal effect on the groundwater in the surrounding area due to the proximity of the river adjacent to and downgradient of the lined cells. Downgradient of the lined cells, groundwater levels will reach an equilibrium with the river due to its proximity, thereby minimizing the "shadow effect". 1.5 AVAILABLE SATURATED THICKNESS The drilling and installation of monitoring wells at the Windsor East site in August 2022 indicated that bedrock was encountered between 15 and 22.5 feet below land surface. Water levels measured on August 12, 2022, ranged from 7.9 to 10.4 feet bgs. Based on this data, the saturated thickness of aquifer present beneath the site ranges from approximately 5 to 13.5 ft (Table 3). The lowest saturated thickness was recorded in MW -11 on the eastern side of the site, which is likely showing the direct impact of dewatering activities associated with the adjacent Parsons mine. Dewatering activities required as part of mining in the absence of a hydraulic barrier wall result in drawdown of the water table and associated decrease in saturated thickness of the alluvium. This has the potential to impact other wells nearby if the decline in water levels is sufficient to prohibit the well owner from extracting the associated water rights from the well. Table 4 presents historic information about the variability in saturated thickness near the site and the impact from mining based on available data. Four of the monitoring wells that were installed at the Parsons Mine Site to observe water levels at the Parsons Mine site, provide evidence of the saturated thickness of alluvium nearest to the Windsor East property. Water levels measured during pre -mining and mining conditions illustrate the expected decline in saturated thickness at a distance of approximately 100 feet from the gravel mines. In particular, the Parsons Mine monitoring well MW -12 is located approximately 100 feet west of a cell that began dewatering and mining in 2019. The water level record for the well shows the range of saturated thickness for the alluvium before and during dewatering activities at this distance. MW -12 is located on the eastern edge of the Windsor East property and is therefore expected to be representative of the conditions at the site as well as of the expected impacts from dewatering during mining near the property boundary. Before 2019, the water table was an average of 6.3 feet above the top of the bedrock at MW -12 and fluctuated over a range of approximately 1 foot above or below this average. During dewatering, the depth to water increased, and the saturated thickness decreased until it was an average of 1.7 feet above the top of the bedrock, with a variation range of approximately 1 to 1.5 feet. Water wells completed in sand and gravel aquifers typically provide approximately 25 to 30 gallons per minute per foot of drawdown of saturated thickness in the well. Domestic wells are typically permitted for maximum pumping rates of 15 gallons per minute (gpm). As a result, less than 2 feet of saturated thickness above the pump intake is therefore likely to be required to provide the allowed pumping rates of 15 gpm. The reduction of saturated thickness of 4.6 ft at MW -12 to 1.7 ft above bedrock suggests that the potential for impact to a domestic well at this distance is likely, however, wells located further from the lease boundary will have more saturated thickness and hence will likely be able to pump the permitted rates. 1.6 HYDRAULIC IMPACTS The hydraulic impacts associated with dewatering around the planned mine cells are expected to spread outward as a function of the aquifer properties of the alluvium, the time elapsed since dewatering began, and the distance of observation from the point of dewatering. The previous observations of the depressed water table (drawdown) OTETRA TECH Page 6111 Windsor East Mine, Exhibit G — Water Information March 2023 due to mining at the adjacent Parsons mine (noted in the previous section) are useful for predicting the impact of the Windsor East mine. In particular, the observations at Parsons well MW -12 (located directly between a dewatered cell and the Windsor East site) represent an ideal location from which the effects of dewatering in the vicinity can be observed. As noted in Table 4, the result of dewatering at MW -12, located at a distance of approximately 100 ft from the nearest cell, resulted in drawdown of 4.6 ft. This response occurred over two years, since dewatering was variable depending on mining rates. A water resources investigation (WRI) study performed by the United States Geological Survey (USGS) (Langer and Paschke, WRI 02-4267, 2002), explored the simulated spread of hydraulic impacts in a hypothetical situation involving the excavation of surface alluvium to bedrock (similar to most of the sand and gravel mine operations along the Front Range river corridors). Appendix G-4 shares this USGS WRI report. The study used analytical and numerical modeling of a pit near a river in a highly permeable unconfined aquifer. This study illustrated that in a hypothetical sand and gravel pit in an aquifer adjacent to a river, a numerical simulation of steady-state drawdown does not result in drawdown exceeding approximately 1 foot at a roughly 0.5 -mile distance from the hypothetical pit. There are no registered wells owned by parties other than Great Western or Martin Marietta within 0.5 miles of the Windsor East Mine property. As a result, there are no parties that are expected to be impacted as a result of either dewatering operations or subsequent development of lined ponds at the Windsor East Mine site. Therefore, detailed localized numerical modeling of hydraulic impacts has not been conducted.Additionally, there are likely mitigating factors to drawdown spread caused by dewatering. Active dewatering may stop and start at a location depending on the mining progress, the proximity of the Cache Ia Poudre River will provide a constant source of water mitigating drawdown impacts, and the aquifer may prove more or less transmissive depending on the location. With this understanding, the modeled spread of the hydraulic effects of dewatering suggests that the impact of the lowering of the water table during mining is unlikely to substantially affect any nearby water wells. 1.7 WATER USE Section 6.4.7 of the Colorado Mined Land Reclamation Board's Construction Material Rules and Regulations: (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. Water use will be at its highest during the mining phase of the project. Mining at the site will intercept groundwater tributary to the Cache Ia Poudre River. Consumptive uses of groundwater at the site include evaporation from groundwater exposed to the atmosphere, water retained in material hauled off -site for processing, and water used for dust control. Evaporative losses at the site are attributable to exposed groundwater in the dewatering trenches for each mine cell. Evaporative losses were calculated as the difference between gross evaporation and effective precipitation. The NOAA Technical Report NWS 33, Evaporation Atlas for the Contiguous 48 United States (U.S. Department of Commerce) was used to determine the site's average annual gross evaporation of 43 inches. Precipitation was obtained from the Western Regional Climate Center for the Fort Collins weather station (053005). The gross annual precipitation for this site was determined to be 15.08 inches. Effective precipitation was calculated as 70 percent of gross precipitation; thus, the average annual effective precipitation was determined to be 10.56 inches. The resulting evaporative loss rate is therefore 27.92 inches. The maximum total annual evaporative consumptive use at the site is estimated at 12-17 acre-feet, which is primarily a function of the water used for dust control (10-15 ac-ft/yr). OTETRA TECH Page 7111 Windsor East Mine, Exhibit G - Water Information March 2023 This Groundwater Monitoring and Mitigation Plan is prepared as part of Martin Marietta's application to the Colorado Division of Reclamation, Mining and Safety (DRMS) for a permit for the Windsor East Mine in Weld County, Colorado. This plan presents the methods and locations for monitoring of groundwater during gravel mining and site reclamation activities. Although adverse impacts to other local users of groundwater are not expected as a result of activities at the mine, this plan addresses how any adverse effects to groundwater would be mitigated, should they occur. Martin Marietta will submit a Temporary Substitute Water Supply Plan to the State Engineer's Office for approval. The temporary substitute supply plan is designed to protect senior vested water rights and mitigate potential depletions of flows in adjacent waterways. 2.1 MINING PLAN Except for Cell A, the mining plan has been designed to allow for up to five quarters worth of groundwater monitoring to occur before excavation below the water table occurs. This monitoring includes monthly water level measurements in the five monitoring wells at the Windsor East Mine site, and five quarterly water -quality sample collection events. To allow for sufficient time for groundwater characterization to occur, mining is only planned to occur in the unsaturated zone until one year's worth of monitoring and groundwater sample collection has been conducted. An exception will be made with regard to mine Cell A. This cell is the easternmost cell in the mining plan and is located within several hundred feet of the Parsons mine. As a result, water levels are already lowered in the area from Parsons dewatering. Since changes to the groundwater flow regime have already been substantialy implemented, trenching and mining below the water table at Cell A with associated dewatering will begin before the five quarters of monitoring are complete. Based on the current mining schedule, mining will expose the water table after three quarters of monitoring has taken place. Following the five quarters of monitoring, dewatering trenches will be excavated around the perimeter of each remaining mine cell on a schedule determined by the mining plan. Dewatering will occur initially adjacent to the area on the east where dewatering associated with Parsons mine has already reduced water levels (Cell A). The bottom of the trench will be maintained at or deeper than the deepest point in the excavated mine cell, thereby intercepting all groundwater before it reaches the mine cell. After collection of five quarters of groundwater monitoring, mining will gradually progress westward, with perimeter dewatering drains preceding excavation below the water table. Groundwater flow into each dewatering trench will be accumulated in connected sumps and discharged directly into the Cache la Poudre River. Following completion of mining activities, mine cells A and C will be finished with a compacted embankment liner from material located on -site, keyed into the bedrock at the base of the mine cell, thus forming a low -permeability bathtub in the mine cell. Once finished, dewatering of the perimeter trench will cease, and the trench will be backfilled, allowing groundwater to return to a state of natural flow around the now -lined mine cell. It is expected that some minor hydraulic mounding may occur upgradient of the lined mine cell, with some "shadow effect" (decline in groundwater level) downgradient of the mine cell. Since no existing water wells have been identified downgradient between the mine and the river, the shadow effect is not anticipated to impact other users. Figure G-6 depicts the anticipated groundwater flow directions resulting from the installation of the compacted liners during reclamation. Mine cells B and D will be backfilled with non -economic aggregate. While this material is expected to be finer - grained than the existing subsurface sands and gravels being mined, they are not expected to represent a significant barrier to flow. Some minor hydraulic mounding may occur to the northwest of each of the cells, but the effect is presumed to be localized and limited to less than 2 feet relative to the surrounding water table. OTETRA TECH Page 8(11 Windsor East Mine, Exhibit G — Water Information March 2023 2.2 MONITORING The monitoring plan will consist of regular data collection from the set of five monitoring wells installed around the perimeter of the Windsor East property (Figure G-3). Data collection activities will include monthly measurement of water levels in wells and quarterly sampling of water quality from wells and surface discharge locations for a minimum of five quarters. Following five quarters of background water quality sample collection and analysis, Martin Marietta will submit a summary of the water quality results to DRMS for review, and a formal request to reduce the analyte list and/or frequency for water quality sample collection, if appropriate. 2.2.1 Water Quality Parameters Martin Marietta will collect water samples from each of the wells and discharge outflow sites and submit the samples to an analytical laboratory to determine water quality for a set of parameters. As part of this process, notes will be recorded on field forms or in a logbook documenting the activities related to sample collection including date, time, measured water level, pre -sampling well purging details, and sample collection documentation. The DRMS recommends a set of parameters for analysis for aggregate mine permitting. These include a list of dissolved metals, radiological parameters, and miscellaneous parameters which include pH and total dissolved solids (TDS). The nature of activities associated with sand and gravel mining involves excavation of large volumes of aggregate materials using industrial machinery. These activities inherently do not result in the generation or release of coliform bacteria, asbestos, chlorophenol, foaming agents, odor, or phenol compounds. They also do not result in a change in corrosivity of water, or color change. As a result, these parameters which are otherwise a part of the DRMS requirements for water quality analysis are excluded from the list of water quality parameters. Likewise, sand and gravel mining does not lead to the generation or release of gross alpha or beta and photon emitters as part of the operation. Martin Marietta acknowledges the preference on the part of DRMS to have gross alpha radiological analysis performed and will include it in the list, but will exclude beta and photon emitters from analysis. Table 5 presents the complete list of water quality parameters proposed for analysis. 2.2.2 Windsor East Monitoring Wells The monitoring plan will consist of regular data collection from the five monitoring wells installed around the perimeter of Windsor East (Figure G-3). Monitoring data will be used to identify potential changes in alluvial groundwater flow or elevation associated with mining and reclamation activities. Baseline data collected from the monitoring program will provide a range of relative water levels associated with pre -mining groundwater conditions. Experience at other sand and gravel mine sites in similar geologic settings shows that groundwater levels tend to fluctuate between two to four feet each year; levels are highest in the summer and lowest in the winter and early spring. Martin Marietta will conduct monthly water level monitoring for the five monitoring wells around Windsor East during dewatering and until groundwater levels have recovered once dewatering ends. Groundwater samples will be collected to document baseline water quality prior to mining, then determine whether any changes have occurred as a result of mining activities. One quarterly water quality sample for laboratory analysis will be collected during each of the five quarters of monitoring to document the baseline water quality around the mine. Based on the historical water level fluctuations observed in the wells associated with the Parsons Mine, the seasonal high and low water levels for groundwater have been evaluated. Water levels are seasonally at their highest elevations in August or September following the irrigation season, and typically at their lowest elevations in February to March when irrigation has been suspended for the longest period of time. During high groundwater levels, the sample is expected to be representative of the groundwater which flows from the agricultural fields toward the river, and during the periods of low groundwater the sample is expected to be representative of alluvial channel water flowing from the west. After five quarters, water quality sample collection will continue to be conducted twice per year while mining, with sample collection timed to be consistent with high and low groundwater levels. The results of water quality sample analysis will be provided to DRMS following the baseline water quality evaluation, and during annual reporting thereafter. OTETRA TECH Page 9(11 Windsor East Mine, Exhibit G — Water Information March 2023 Appendix G-3 includes procedures for collecting water samples. These procedures include a process of pumping to purge standing well water, then using the pump to remove water for sample collection, then placing the water in sample bottles obtained from the analytical laboratory. At the end of purging, the pH of the water will be recorded using a handheld pH meter. Samples for dissolved constituents, primarily inorganics and metals, will first be filtered through a 0.45 -micron filter to remove suspended solids. Samples will then be stored on ice in a cooler for transport and submitted for analysis of the constituents listed in Table 5 under chain -of -custody protocols. If sufficient data is collected during the life of the mining operation, and a demonstration can be made that project impacts to the groundwater system have been minimized, Martin Marietta may request the approval of a Technical Revision to revise the water level monitoring frequency or water quality sample collection frequency at a later date. 2.2.3 Domestic and Irrigation Water Wells No active water wells (water -supply wells) were present within 600 ft of the lease area. 2.2.4 Dewatering Discharge Based on data collected from monitoring wells on the adjacent Parsons Mine property, the depth to groundwater fluctuates by two feet depending on the season but averages about 7 feet below ground surface. Due to the absence of large quantities of potential pollutants on site (no on -site processing or concrete or asphalt production), the mining and reclamation operations are not likely to affect groundwater quality on or off the site. Martin Marietta's Parsons facility complies with applicable requirements in the site CDPS General Permit COG501594 for Discharges Associated with Sand and Gravel Mining and Processing. CDPHE WQCD considers stormwater runoff combined with mine dewatering water to be process water. Current discharges at the Martin Marietta Windsor East Site and Parsons Pit are permitted as process water. As such, process water discharges are subject to the process water provisions in the general permit. Martin Marietta plans to obtain a City of Windsor Grading, Erosion and Sediment Control Plan (GESCP) Permit and comply with applicable requirements as stated in the City of Windsor's Municipal Code/Ordinance Chapter 13, Article, Stormwater Quality. 2.3 MITIGATION The available monitoring well data will be used to identify changes in alluvial groundwater flow associated with mining and reclamation activities. Baseline data collected from the monitoring program will provide a range of relative water levels associated with pre -mining groundwater conditions. These data will be utilized to evaluate the nature and extent of the change to the prevailing hydrologic balance and if necessary, provide for the development of corrective actions. Well owners in the section below refer specifically to owners of wells from which extracted water is put to beneficial use, such as water wells, irrigation wells, etc. Owners of monitoring wells are not considered well owners in this context since a change in water levels for these wells does not represent material damage. In the event of a well owner complaint, Martin Marietta will commit to reporting any complaints received from well owners to the DRMS within 48 hours, to investigating the complaint as soon as practical, and to submitting the results to the DRMS for evaluation within 30 days. For the investigation, the first level of response will be to review water level data from the monitoring well network and, if available, a measurement of the water level in the plaintiffs well. The information will be evaluated to determine if there is a reason to believe the plaintiffs complaint may be tied to dewatering or the lined reservoirs. If the data indicates that there is no reason to believe the plaintiffs well was impacted by dewatering or the lined reservoirs, that will conclude the action taken by Martin Marietta. If the data does not clearly show there is no impact, as a second level of response, Martin Marietta will present a contract to the well owner that requests access to the well to perform a mechanical and electrical inspection and testing of the well and associated system, e.g. pressure tank. The agreement will explain that if the problem with the well is not due to a lower water level and is instead due to a mechanical or electrical issue, the well owner will be responsible for the repairs. If the OTETRA TECH Page 10111 Windsor East Mine, Exhibit G — Water Information March 2023 well is determined to be in good working order and the problem is due to a lower water level, then the mining - associated impacts will be addressed to the satisfaction of the DRMS. If the DRMS determines that the impact on a well for which temporary mitigation has been initiated is not a result of Martin Marietta's activities or is not solely a result of Martin Marietta's activities, Martin Marietta will reduce or cease mitigation accordingly. In the event of a complaint that a well has become unusable, and based on the inspection results as noted above, Martin Marietta will implement mitigation measures within 7 days. Mitigation measures would include providing a temporary alternative water supply that meets the documented historic well production or need until further investigation can be conducted to determine if the well condition is due to the mining operation. Martin Marietta will begin to implement one or more mitigation measures if mining or reclamation activity is determined to be a significant contributing factor to groundwater changes requiring mitigation. Temporary mitigation measures may include, but are not limited to: Compensation for well owners to use their existing treated water system to replace the well production loss; Provision of a water tank and delivery water as necessary to meet documented historic well production or need; and Other means acceptable to both the well owner and Martin Marietta. Long-term mitigation measures may include, but are not limited to: Cleaning a well to improve efficiency. Providing an alternative source of water or purchasing additional water to support historic well use with respect to water quantity and quality. If needed, water quality parameters will be checked in affected wells to ensure alternative sources support the historic use. Modifying a well to operate under lower groundwater conditions. This could include deepening existing wells or lowering the pumps. All work would be completed at Martin Marietta's expense except for replacing equipment that was non-functional prior to mining. If existing wells cannot be retrofitted or repaired, replace the impacted well with a new replacement well. Design and installation of a cistern. If a groundwater mitigation action is required, Martin Marietta will notify the DRMS of the condition, action taken and report the results and present a plan for monitoring the mitigation. 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I • • !• Se ..Iy • • • • r • V . • w ••/ • a • • Legend Great Western Lease Area Mining Cells Valley -fill deposits Qf: Flood -plain deposits, sand, silt, and clay Qt: Terrace deposits, arkosic gravel and sand; contains some loosely cemented sand and gravel Fox Hills Sandstone Kfh: Fox Hills Sandstone undifferentiated 4. ♦ I w a • • • • • I • • • 4 • • ■ • • I •' • w * r a I • 3P• 19 t * • a K ♦ • • • w • o ! r!♦ ° 0 • a • •I • 4. •i a. a • a/r•er.aiaall •aLuA•rw•'r X1/11.1 • 1chv•5j}••• r r IF ) = it a • r • • • ♦ • Y G-2 Project No.: 117-8741006 Exhibit • Le end Great Western Lease Area Mining Cells Primary Monitoring Location Parsons Mine Wells 8/22/2022 - O:\PROJECTSILONGMONT18741\117-8741006\GIS\MXD\EXHG4 REGISTEREDWELLS.MXD -JEREMY.ANDRYAUSKAS NG EDIT.MXD - KATELYN.GOEN 2/15/2023 - \\TT.LOCAL\IER\PROJECTS\LONGMONT187411117-87410061GIS\MXD\EXHG5_PREMIN Primary Monitoring Location Flow Direction during Mining Flow Direction Post -Reclamation Table 1. Well Inventory Search Results Permit Number Contact Name Town ship 280593 277000- MARTIN MARIETTA MATERIALS INC HALL-IRWIN CORPORATION Range 6.0 N 67.0 W 6.0 N 67.0 W Section Q160 36 25 N E SE Q40 NW SW UTM X 513402.6 513411.5 UTM Y 4477581 4477818 Distance < 600 ft < 0.5 mi <100ft <100ft Yes Yes Yes Yes Permit Category 89706--A LAUER BRETT T & MARY K 6.0 N 67.0 W 26 SE SE 512509.3 4477876 640 ft No Yes Monitoring/Observation Monitoring/Observation Residential 280591- MARTIN MARIETTA MATERIALS INC 6.0 N 67.0 W 36 NE SW 513702.1 4477332 900 ft No Yes Permit Issued 5/7/2009 3/28/2008 4/21/1977 Construction Date 4/20/2007 3/1/2007 4/29/1977 Use(s) Monitoring/Sampling Monitoring/Sampling Domestic Elevation Depth 4725 4727 14 14 Screen Screen Top Bottom 6 4 32 17 280588- MARTIN MARIETTA MATERIALS INC 6.0 N 67.0 W 36 N E NW 513702.5 4477496 940 ft No Yes 280590- 1472 -R -R 277001- 113762--A 280589- 46989-MH 276998- 280592- 310649- 34951-M 273582- 80887- F 34953-M 43115- 34954-M 80889-F 34952-M 317847- 34941-M MARTIN MARIETTA MATERIALS INC WEST WELD AG I HALL-IRWIN CORPORATION M WATERCO LLC MARTIN MARIETTA MATERIALS INC PARSONS, SALLY HALL-IRWIN CORPORATION MARTIN MARIETTA MATERIALS INC GREAT WESTERN DEVELOPMENT CO EASTMAN, KODAK BROE LAND ACQUISITIONS II LLC FRONT RANGE ENERGY LLC EASTMAN, KODAK HENSEL PHELPS CONST EASTMAN, KODAK FRONT RANGE ENERGY LLC EASTMAN, KODAK JOSEPH ENERGY LLC EASTMAN, KODAK 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 6.0 N 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 67.0 W 36 35 25 25 36 36 25 36 26 35 35 26 26 26 26 26 26 26 34 N E SE SE SW N E N E SE N E SE NW NW SE SW SE SW SE SW SW SE SW NE SW NE SE SE NW SE N E N E SE NW SE NW SE NW SE N E N E 513594.4 512410.1 513792.4 513394.6 513941.6 514004.4 513410.8 514062.2 512567.4 511773.7 511749.1 512052.5 511752.9 511997.7 511761.9 511838.4 511484.6 511413 510971.7 4477089 4476792 4477895 4478305 4477286 4477189 4478397 4477002 4478569 4477440 4477321 4478393 4477922 4478388 4478175 4478531 4478135 4478225 4476873 960 ft 1300 ft 1320 ft 1700 ft 1750 ft 1970 ft 1980 ft 2300 ft 2580 ft 2790 ft 2800 ft 2880 ft 2900 ft 2950 ft 3200 ft 3690 ft 3980 ft 4280 ft 5300 ft No No No No No N o N o No No No No N o N o No No No No No No Yes Yes Yes Yes Yes Yes Yes Yes Yes No No No No No No No N o N o N o Monitoring/Observation Monitoring/Observation Monitoring/Observation General Purpose Monitoring/Observation Residential Monitoring/Observation Monitoring Hole (Notice of Intent) Monitoring/Observation Monitoring/Observation Monitoring/Observation Monitoring/Observation Residential General Purpose Monitoring/Observation Residential Monitoring/Observation General Purpose Monitoring/Observation Monitoring/Observation Monitoring/Observation 5/7/2009 5/7/2009 5/7/2009 4/29/1982 3/28/2008 4/21/1980 5/7/2009 4/17/2007 3/28/2008 5/7/2009 8/22/2018 4/11/1989 5/14/2007 5/9/2017 4/11/1989 4/11/1989 5/9/2017 4/11/1989 7/1/2020 4/11/1989 4/20/2007 4/19/2007 4/20/2007 3/2/2007 4/28/1980 4/19/2007 4/19/2007 3/1/2007 4/20/2007 7/20/2017 5/10/1989 12/13/2007 1/23/2006 5/8/1989 9/19/1970 5/10/1989 2/1/2006 5/10/1989 3/19/2020 5/8/1989 Monitoring/Sampling Monitoring/Sampling Monitoring/Sampling Irrigation Monitoring/Sampling Domestic, Stock Monitoring/Sampling Monitoring/Sampling Monitoring/Sampling Monitoring/Sampling Monitoring/Sampling Monitoring/Sampling Commercial Industrial, Irrigation, Other Monitoring/Sampling Domestic Monitoring/Sampling Industrial, Irrigation, Other Monitoring/Sampling Monitoring/Sampling Monitoring/Sampling 4723 15 4724 16 4727 16 4724 9 More Info 14 https://dwr.state.co.us/Tools/WeIlPermits/3639673L 15 https://dwr.state.co.us/Tools/WeIlPermits/3627148E 32 https://dwr.state.co.us/Tools/WeIlPermits/9065892 4 14 https://dwr.state.co.us/Tools/WeIlPermits/3639673) 6 14 https://dwr.state.co.us/Tools/WellPermits/3639673G 6 4 25 12 4722 18 4722 18 4740 24 4724 17 4758 26 4753 10 16 https://dwr.state.co.us/Tools/WeIlPermits/36396731 https://dwr.state.co.us/Tools/WellPermits/0221570 10 https://dwr.state.co.us/Tools/WeIlPermits/3627148F 25 https://dwr.state.co.us/Tools/WeIlPermits/0914278 6 16 https://dwr.state.co.us/Tools/WeIlPermits/3639673H 6 16 https://dwr.state.co.us/Tools/WellPermits/0046989 4 25 https://dwr.state.co.us/Tools/WellPermits/3627148C 6 16-https://dwr.state.co.us/Tools/WeIlPermits/3639673K https://dwr.state.co.us/Tools/WellPermits/3688007 5 10 https://dwr.state.co.us/Tools/WellPermits/0297546O 32 12 18 29 18 16 13 32 https://dwr.state.co.us/Tools/WeIlPermits/3616219 https://dwr.state.co.us/Tools/WeIlPermits/3679484A 8 18 https://dwr.state.co.us/Tools/WeIlPermits/0297546Q https://dwr.state.co.us/Tools/WeIlPermits/9064312 8 18 https://dwr.state.co.us/Tools/WeIlPermits/0297546R https://dwr.state.co.us/Tools/WeIlPermits/3679484C 6 16 https://dwr.state.co.us/Tools/WeIlPermits/0297546P https://dwr.state.co.us/Tools/WeIlPermits/10004233 16 6 16 https://dwr.state.co.us/Tools/WeIlPermits/0297546E Table 2. Parsons Mine Well Construction Summary Land Well Location Surface Top of Screene i Casing Top of Elevation Elevation screen (ft Latitude Longitude Northing Easting (ft asl) (ft asl) BTOC) MW -1 40 27'09.1 N 104 49'40.2 W 1408407.20 3187071.64 4732.55 4734.88 7.2 MW -2 40 27'23.0 N 104 49'40.2 W 1409820.68 3187507.17 4739.56 4741.94 19.2 MW -3 40 27'28.6 N 104 49'43.7 W 1410378.60 3186772.58 4743.25 4745.43 20.7 MW -4 40 27'08.0 N 104 50'03.3 W Destroyed est 4731 4.7 MW -5 40 27'28.1 N 104 50'06.5 W 1410302.087 3185005.977 4748.44 4748.51 18.7 MW -6 40 27'18.1 N 104 50'12.9 W 1409320.737 3184458.427 4749.83 13.7 MW -7 40 26'52.2 N 104 50'14.7 W 1406761.58 3184129.57 4724.06 4726.31 5.7 MW -8 40 26'42.3 N 104 50'05.4 W Destroyed est 4721 6.3 MW -9 40 26'40.0 N 104 50'23.0 W 1405423.6 3183773.8 4727.01 4729.90 5.7 MW -10 40 26'47.8 N 104 50'18.5 W 1406223.77 3184126.00 4723.11 4728.27 3.7 MW -11 40 26'37.0 N 104 50'03.3 W 1405142.17 3185307.82 4724.58 4727.27 5.7 MW -12 40 26'55.8 N 104 50'30.9 W 1407046.36 3183142.78 4725.58 4728.19 5.7 MW -13 40 26'55.4 N 104 49'41.5 W 1407007.63 3186986.18 4721.13 4723.89 MW -14 40 26'46.1 N 104 49' 54.7 W 1406061.78 3185977.16 4721.42 4723.87 Note: Surveyed coordinates are Colorado State Plane North, US ft, NAD83. Table 3. Windsor East Monitoring Well Construction Summary Well Measuring Point Screened Interval Location Elevation (ft BTOC) Top of Bottom Casing Top of of Northing Easting (ft amsl) Screen Screen MW -05 1407363.18 3180756.42 4741.04 4.0 24.0 Depth to Depth to Water Bedrock Total Measured Depth Date (ft BTOC) (ft BTOC) 24.0 8/12/22 8.9 22.5 MW -06 1406448.96 3180558.21 4734.84 7.0 17.0 19.0 8/12/22 7.9 16 MW -07 1405083.81 3180568.65 4733.71 6.0 16.0 17.5 8/12/22 10.4 16 MW -10 MW -11 1407540.29 1406241.22 3183012.41 3183097.25 4728.44 4727.64 8.0 6.0 18.0 16.0 20.0 20.5 8/12/22 8/12/22 8.8 16 10.2 15 Notes: amsl = above mean sea level; BTOC = Below Top of Casing Coordinates are reported in Colorado State Plane North (US ft, NAD 83) Table 4: Saturated Thickness and Dewatering Impacts at Parsons Pre -mining Conditions Average Mining Conditions Minimum. Maximum Average 7.0 7.0 13.5 8.5 9. 7.3 7.2 Est Drawdown / Change in Saturated Thickness 0.1 ft 8.7 6,6 4.2 S,;2 6.1 7.2 5.3 6.9 1.7 3.3 1.7 1.9 ft E 3-5 ft 4.6 ft Table 5. Water Quality Sampling Parameters Parameter Aluminium - Dissolved Applicable Water Quality Standard Concentration 5 mg/L Notes and Field Filtration Filter in field (0.45 micron) Container Volume 250 mL Preservative HNO3 Hold Time 180 days Antimony - Dissolved 0.006 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Arsenic - Dissolved 0.01 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Barium - Dissolved 2.0 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Beryllium - Dissolved 0.004 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Boron - Dissolved 0.75 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Cadmium - Dissolved 0.005 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Chromium - Dissolved (CrVI) 0.1 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Cobalt - Dissolved 0.05 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Copper - Dissolved 0.2 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Cyanide - Free 0.2 mg/L 500 mL NaOH 14 days Fluoride - Total F 2.0 mg/L 125 mL Temp (< 60C) 28 days Iron - Dissolved 0.3 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Lead - Dissolved 0.05 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Lithium - Dissolved 2.5 mg/L Filter in field (0.45 micron) 250 mL NNO3 180 days Manganese - Dissolved 0.05 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Mercury - Dissolved 0.002 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Molybdenum - Dissolved 0.21 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Nickel - Dissolved 0.1 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Nitrate (NO3) 10.0 mg/L as N Filter in field (0.45 micron) 125 mL Temp (< 60C) 28 days Nitrite (5O2) 1.0 mg/L as N Filter in field (0.45 micron) 125 mL Temp (< 60C) 28 days Nitrate+Nitrite (NO2+NO3), dissolved 10.0 mg/L as N Filter in field (0.45 micron) pH 6.5 - 8.5 Measure in field 125 mL Temp (< 60C) <24 hrs (lab) Selenium - Dissolved 0.02 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Silver - Dissolved 0.05 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Sulfate - Total 250 mg/L 125 mL Temp (< 60C) 28 days Thallium - Dissolved 0.002 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days TDS 400 mg/L Lab Filtration 500 mL Temp (< 60C) 7 days Uranium - Dissolved 0.0168 to 0.03 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Vanadium - Dissolved 0.1 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Zinc - Dissolved 2 mg/L Filter in field (0.45 micron) 250 mL HNO3 180 days Gross Alpha Particle Activity 15 pCi/L 1 L HNO3 180 days Chloride, dissolved 250 mg/L Filter in field (0.45 micron) 125 mL Temp (< 60C) 28 days Notes: Detection Limit / Reporting Limit must be equivalent to the water quality standard or lower. APPENDIX G-1 BORING LOGS AND WELL COMPLETION DIAGRAMS WINDSOR EAST AND PARSONS MINE MONITORING WELLS Site Name: Site Location: Boring Number: Latitude: - Date Started:- -� �ce, Rig Type: i'``''\ . r_ Drilling Method: , C ! > S " -. �.- I' :,4bitik cs- Martin Marietta Surface Elevation (Feet): Overburoerl Thickness (Feet): Boring Total Depth (Feet). Depth (Feet) (1) Grain (2) Round (3) Grads isk1/44ste Logged By: Longitude: Date Completed: Drilling Contractor: Borehole Diameter: Page of as 4,3 7- Depth to Water (Feet): •� Depth to Bedrock (Feet): L 1 r______ Backfill Type: l ( mss- C 53 ng: I )u ldwatel etui &Odwes � �'Description, Time, Material and Comments Iiioi t w. t d 4 w _ , � 2T 1 ♦ v+� iecal "y ♦7t^- -\tit` y�i,t brt.."..4:0. !�t ,,, ) c'• AA " Iry �'t'13---ni ilk*, size �.� - e> , 1y ' _.r. ) ' 1 V Sine ji,‘tralita. 1 To S 4-- - -C1 ct( t 1 (I S /bat% Sbitt41 4 y e ti f f !u .ev ' 46‘t; -ti V6 -- - 5 n Al ( -.37)4 I +.w+a. ..e.' - w....:.r......�. .. _ 0 I \ Ittj k ZAC) -- -- .....�_..,� .a \CACc.\\\\k f ..-N.C Ca Size;B=Boulder, �'�-Cobble, . ing: P=poorly R=rounded, graded, rwsubrounded, M=moderately G -Gravel, a= subangular. graded, S=san d. W=well V=very; A�=angular graded; _ F -Fine, �1��ectium, Xzsee description ..•-..�.• �C�Goar5 e al e3e-c-s+ a Site Name: _ s. Site Location: Boring Number: Latitude: Date Started Rig Type: Drilling Meth Surface Elegy Overburden Boring Total Marietta Page 2 of Martin .�--= Logged By: Longitude: z Date Completed: '$ - e> - ` (---- \\ti.. (\eV. ' Drilling Contractor: S Diameter: . Borehole , i7,\ ration Thickness (Feet): (Feet):��,,S Depth Depth to to Water Bedrock (Feet): (Feet): �� `,� ci I Depth (Feet): - Backfill Type: (r m to CD '_ Sample Mites Material Description, and Comments 0 a, is `a, Time, .�. .N U) c •- o C c a c V- L O 6 'u.C�`�t 6 c2 i,� , /eft, Cer-srti\V- BerAc) IN,)(e_ Cm LA__ , itren;I: gen\--w:k\-c_ se cAAI, .\ Src_i"---_____a 1�` Sono \4--L\A-\ Wa _ — 6->c 9\9e-- 7-, e- �- O\ C S\t - 7_ -' ,,, ., - MI it -A cis Lee() 4 . S - c , Lt\v..)ca , I Sgii-\ 1 - ---) geAVosttick t•e, _3 CcLAteS C -1O CCk-cO cH OtA- \-\44.v\i Ceiti-eirvC- V1Ve I/E Qb 19(‘Q C \\ s er \CN cts keb eke* % \r. L \r\t\q, etr\?)(d--%\ ‘-iLt VC -Vito ,.............„ c \` _..a —s- 11 (1) Grain Size:B=Boulder, P=Cobble, G=Gravel, S=sand, V=very, F -Fine, M=Medturn, C=Coarse (2) Rounding: R= rounded, r=subrounded, a=subangular, A=angular (3) Grading: P=poorly graded, M=moderately graded, W -well graded, X -see description C. 1� cis k „pc pin epVSj b_sa e_c utak,\Dt ..S tNfOmY\i . I IA Pocik c\h cootAfe- cIrttsci- 0\ \<0 00-1" Lesko &-- -2 c) eaaolPtlitivci -6 Nsi it eQc,\N c;� c ciit\LAA!' cJ C)-60-itb SeW weld o\ (9cc cerva Asti %:.tc\k if\ Martin Marietta Page 1 of Site Name: Site Location: Boring Number: (} Latitude: LtQ. 41`7 2 S� Date Started: '$ i t 1 24 Z2- (2: So Rig Type: CP.KS$'- '7. OD ° [ ►r , Drilling Method: -(of lv W Surface Elevation (Feet): 9 7 '; Ts" 35 Overburden Thickness (Feet): Boring Total Depth (Feet): q 1 Ct Depth (Feet) 4, Co 1 . 3 Logged By: _ Longitude: Date Completed: Drilling Contractor: Borehole Diameter: Depth to Water (Feet): Depth to Bedrock (Feet): Backfill Type: Time, Material Description, and Comments B b,�, i D V( Yr. 0 SF tolzo >c )(4'1 G 0 f'V c ,. c tG 7 (1) Grain Size:B=Boulder, P=Cobble, G=Gravel, S=sand, V=very, F=Fine, M=Medium, C -Coarse (2) Rounding: R=rounded, r=aubrounded, a=subengular, A=angular (3) Grading: P=poorly graded, M=moderately graded, W=well graded, X=see description in Marietta Page . . Site Name: r Site Location: _co,..„ 1 s Boring Number: Latitude: Date Started: Rig Type; Drilling Method: Uo(Io 5t -e.— Surface Elevation (Feet): 1.41.--1 '7O4 Overburden Thickness (Feet): 7 Depth to Bedrock (Feet): Boring Total Depth (Feet): 17 /z ( — 1ti'IL0—O `7 1tp, 4f,f3c C410i / 2022. c —;≤-:3OO v-ced . Logged By: be,„(.1 1 , 1, ef Longitude: — 1 Lisr.c12'7Date Completed: 01 Z (e of Drilling Contractor: Ae De-, II, J Bbrehoie Diameter: g.-.1 f , „r L. Depth to Water (Feet): i7 ,-►f., Backfiill Type: Over burl , $e l �' ► Ltd rJeR t, /OW 1. 2fiseet'404-0 4 v rG ` ` t 't C Patty { r vrr rap 0 4-v _Se, - Scrr., ". �nL Lip ►uc�.rc, I G '4 3,Y�tJt�GA3ln$_ c c { Uc 2" C VC . of 0 gia (1) Grain Size:B=Boulder, P=Cobble, G=Gravel, S -sand, V=very, F=Fine, M=Medium, C=Coarse (2) Rounding: R=rounded, r-subrounded, a-subangular, A=angular (3) Grading: P. -poorly graded, M=moderately graded, W=well graded, X =see description O01 B 0 S :3 Martin Marietta Page I of Site Name: Site Locationst, Boring Number: +} A W i s x Logged By: J Latitude: ( ; Date Started:;. Rig Type: ...cc -- Drilling Method: 1.40,110,_, Surface Elevation (Feet): Overburden Thickness (Feet): _ Boring Total Depth (Feet): Depth (Feett 2O1 ,L Longitude: Date Completed: 202.M - Drilling Contractor: Borehole Diameter:. Depth to Water (Feet): Depth to Bedrock (Feet): I BackfiltType: t•�i3� � fi r� �„ (,Fe -1 Time, Material Description, and Comments 0 tt v -eke- i t 01 s i l "may c. 4- 42_0 �... .C1 !C` u--- c-1„, 5602 I to zD 4,, (1) Grain Size:B=Boulder, P=Cobbte, G=Gravel, S:=sand, V=very, F=Fine M=Medium, C. -Coarse (2) Rounding: R=rounded, r=subrounded, a=subanguiar, A=angular (3) Grading: P=poorly graded, M=moderately graded, W=welt graded, X=see description ict Site Name: (qr.' .r. Site Location: Boring Number: mVV- 4 Latitude: 9 . 4./16 6 X! Date Started: 1 1292 S!3 Rig Type: C"U+rtzsue^ 3D° Drilling Method: it o t t cA.J Surface Elevation (Feet): '727, 4,3C Overburden Thickness (Feet): Boring Total Depth (Feet): 2.tI Martin Marietta Page of Depth (Feet) O Logged By: 1:T.tv r Longitude: if, 4.2 1 Z Date Completed: 91 t 1 Zd 22.. Drilling Contractor: A��,�,-�„ Borehole Diameter: S Depth to Water (Feet): Depth to Bedrock (Feet): 1S" Backfill Type: Ano,.. 11 B ns c its c ,42 c ca Time, Material Description, and Comments +t9 it,t,E N1/4, 1,, , C-1„ ` W+►a‘s 3 -5 101,1 1 it (1) Grain Size:B=Boulder, P=Cobble, G=Gravel, S=sand, V=very, F=Fine, M=Medium, C=Coarse (2) Rounding: R=rounded, r=subrounded, a=subangular, A=angular (3) Grading: P=poorty graded, M=moderately graded, W=well graded, X=see description, #F CLIENT .moor 1V°Y h ArnertC& BOREHOLE LOG PROJECT LOCATIO wi>ndSoF, CO n PROJECT NO . L F- O 5 3 S A,d%1-tt i G1�clY� GiORTH _ • EAST DRILLER ►✓T0\LLINQ ENkNECRS INC. RIG CM BITS S.2S H • S.•A.I FLUIDS LOGGED BY Charceh4 a. BH NO. PAGE DATE START 4/1 /7-b°1 DATE FINISH 4/(Q1200 g'/2ooR GOD ELEV. TOC ELEV. TOTAL DEPTH WATER DEPTH SAMPLE TYPES: C" Cuttings WS Wash Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Ocher SAMPLER SPECIFICATIONS: ..}. Length Z-5 Material S y2'21 O.D. 2' Liner 1.D. I .' Other -- DEPTH (FT) BIT CASI C SAMP NO. SAM? TYPE RECOV. FT/FT BLOWS per 6' SYM SURFACE CONDITION; Gra.sS ....VAPOR SOIL/ROCK DESCRIPTION ac 11S Core • 2 = 73 -...5 _ _ E. =-10 S,2S H S.A ?S A� e1-st to 3/ 0 *'0 3.0 - Ctrttiy,9 - 510 AMID__. CUN. . Br0wv,corn 2 S0.►nd -AYELC•e..- Yoo1s, Y)0 st-. --3 SS y VI " 24.,tt 5 .� ssI 3'-jo - - 3.O'`�o 4.Sr7StLT AND C.Lf1`i �1rowh -----a-1,44.' 1;�t1-� sew1/4,51 1 � 1Jc., y SIOv1J-. UP 'k 0 2- i vs.C.ln 1,1 clichmtel Mo°s� 7 4.Q -to 5.O NO RE ov'ER"( Au3eYP,rj ti, 17. 5.011.0 C1.01 -. e_. Ai, S\ LI AND .. Stoop_ U i to 2- i ,neln r,-, d z arn.e .e,1. enOiCt. Rooc4tt D,1%,5 due .1, giOv1.Qr SS 10 �K 13 SS2 q' "to 11/ Q.& 1© 9.V silfq AND CRAV6L lUOwv, rnRol d.e.vlsL., I\li'& Sit — t,11, eas- orvil See. A'Ilo-rLoe1 11 00 DENSITY: GRANULAR: 0 —lo Loose 10-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-0 Med Stiff 0-15 Stiff 15-30 Very Stiff PROPORTIONS: 0-10X. Trace 10-207 Little 20-357. Some 35-507 And REMARKS/WEATHER 6©F Suvw7 I'IC STATUS PRELIMINARY. _ FINAL: ►II .nvir•caGr-ovp Limited C+entwv-sesi. bolo+-om> CLIENTLatcA.Y Q 1VoY to A ' erko PROJECT LOCATIO PROJECT NO _ l,_F_^ O S $ BOREHOLE LOG BH NO PAUL "- OF 3�___.--._. . NORTH DRILLER'1LLINa° Et'I \NEERS INC. DATE START 4/18/20n3 ' EAST RIG C M E 45 DATE FINISH 4A �Zoo1- COD ELEV BITS g.2S" H.S. A,1 FLUIDS --- TOTAL DEPTH 16 TOC ELEV. LOGGED BY Char ©ev, S . WATER DEPTH 9 / SAMPLE TYPES. Cuttings WS Wash (SS�Split Spoon NX NX Core ��((' Dry Core CS Continuous Sampler Other. SAMPLER SPECIFICATIONS: Length e.ngth '5 - Material S le e'! D '�' -- Liner — I.D. 1-9'' Other DEPTH (Ii') BIT CASING SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6' SYM SURFACE CONDITION: a',12-C S0IL VAPOR PID❑ PI0❑ DO HS Core SOIL/ROCK DESCRIPTION —Io t -it -17 -►3 - =-(4 -1S = -16 - :1 -fig 19 7 l- 8.2s l.y•S{i Zs' � R µ \�/� k)? ht..k._ N GI R' to uJE.o' MO R��o' = A ugerecl -10 14' 111-0t014.0' - Cott sq - SAND ANb GRAVEL- soYne. s;t{- sowsAor-. = iZotJ 1A d5((;r 8,e_i'b sior\N . .- - Z44. —y 24L Z, 32 SS3 14/ to l6' 14.0 ko (5.Z! - SILT �Yow� veYy sk;�-c some sow.( we.j- 15..2'fio 16.0' — SILTS- oNE. , Qt.QV _ AND OF BORE,HoLr _ vQY s L_ -tack. sovw�} i.( we.atk9rea. U eY wkc9is `A. ere -el to 15 .S' 1 1- vb o f OREMok..E Ai- 16_0 sv�S 1001. W\ovL\ ©Yiv,q vie_. V\1 - 1 { 1/4j = ,..-....- _._ ----.._._ LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER S`QQ `rnN I GRANULAR: 0--10 Loose 10-30 Med Dense 30-50 Dense X50 Very Dense COHESIVE: 0-4 Soft 4-8 Mod Stitt 8-15 Stitt 15-30 Very Stiff 0-10X Trece 10-20X Little 20-35X Some 35-509: And �( U OF S U 1/\V / LAC STATUS. PRELIMINARY: FINAL 0/ ►II EnvtroGroup Limited CvT.2n 2 Color raap CLIENT. Lafctr z kk it, AYneyica. PROJECT LOCATIO V`) iv►d Sow CO PROJECT NO. L -o538 NORTH EAST C RD ELEV. TOC ELEV BOREHOLE LOG Andy c3/4 - DRILLER -MU -Ng EnctINE RS INC. RIG CME.-3-S BITS'.ZS H • G.- A.1 FLUIDS LOGGED BY Char©evt S • RH NO. PAGE OF 3 DATE START 4-A8i2oo DATE FINISH 4/(' f Zsb�- TOTAL DEPTH ti WATER DEPTH q SAMPLE TYPES: ,C�7'� Cuttings 4?.$) Split Spoon DC Dry Core Other WS Wash EX NX Core CS Continuous Sampler SAMPLER SPECIFICATIONS: Length Z •5 O.D. 1" 1. D. l .� •r Material Steel Liner Other --- r----S0IL i FT) _NIT CASING DAMP N0. DAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: Gr. G E.GDEPTH VAPOR SOIL/ROCK DESCRIPTION P1FED❑ Bs HS Core --0 zy PVC-©_o�"sitsc o 1 r+n = t = :3 ^y _ , 6 - _ -10 g 2s H.S.A 4.)-S 3.-D. S ' g CY2.tL A -puRE GoLD BtNTONITE COARSE CHtP t 3/e i0 -w) SftiCcs.80,, j tC%io Loch, C0.St-v15 - = Cop R;Ser' —33 to I.2r CotiCY4A. 0 4o Zf Svre.e,,,-9-:22 - IS —' B..e,..-1O,;tn 2'fb 6' Cap � S .�-'- t S. S' SdtMO 6' 1 O 16 l- _ 1 I /l r`ATf —___ .__ Q� GRANULAR 0-10 loose 10-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-d Soft e-6 Med Stiff 5-15 Stiff 15-30 Very Suit PROPORTIONS: 0-10X 10•-20X. 20-357 35-50X Trace Little Some And REMARKS/WEATHER �VHvt+ !.Ole STATUS. PRF LIM,!NARY _ .__ FINAL: EnviroGroup t_imitt3ci con casnniel. Cloloret7q r:I.IENT _l 1G�Y NotL America PIICJECr' LOCATiO wt s_ or, Co PROJECT NO LF -O538 • iNt)RTii GOO ELEV. TOC ELEV BOREHOLE LOG Auch, P ci c�Yd DRILLER ✓1k1L1.(Ng E I iNECQS INC. RIG C M E - 35 BITS R.2S"H.C. ..!FLUIDS LOGGED BY CharceV► s. BH N0. PAGE �_ OF _ DATE START 4/1 2/2oo DATE FINISH 4A '2 200? TOTAL DEPTH 30.3' WATER DEPTH I4' SAMPLE TYPES. C Cuttings WS Wash Spill Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: SAMPLER SPEC)FICATIONS: Length Z,,5 O.D. Z Material Steel Liner Other DEPTH (Pr ) -1 L K-3 S _C BIT CASING 2..2S t1.S.A 4.2su 1.1). SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6" M URFACE CONDITION: Gra SS SOIL/ROCK DESCRIPTION SOIL VAPOR P150 FD❑ ac HS Core /luge0a j *0 4' `04.0' cutt- C ILT Au2' CLAY 'BYowi o iiil e._ Saute It1}i.a. I = Yave 1 tra c.e Yeoto (Yi 01St ' Jj 22 24 4' 3 4 0 LOC STATUS. PREI.IMINARY: FINAL: S$ 1 4.0'x"0 5.4' 4/ tog SILT AND CLAY. -BYOWM -St7 .2' 10 6.0 No ZFc k`t AUgQrec3—`{o q' Ct*1hrc s1L_-T4ND.` CLAY, 3row� tl t� s c ,:t►�tl� gYAVe.1 , "D0.Wip. enviro.roup Limited JI(P ConConnlml, Colorruyr. LI..it r LfaTcoA. (Ve Th America PROJECT LOCATIO VONc)Sor, GO PROJECT NO. LF-O53g NORTH if FAST G RD ELEV. TOC ELEV. SAMPLE TYPES: BOREHOLE LOG DRILLER ✓r\t,1IN, Er,s INEERS INC, IG CME �S BITS &2S'H•S. A.1 FLUIDS LOGGED BY Char©eo Cuttings WS Wash S Split Spoon NO NX Core Dry Core CS Continuous Sampler 42ther�_ -- DEPTH BIT (FT ) CASING t2 44 5 SOAP NO. .S BH NO. PAGE 2- OF •G -- DATE START 4-AS/20457- DATE FINISH 4/11 /2-003 TOTAL DEPTH 38,3 , WATER DEPTH ti 4' SAMPLER SPECIFICATIONS: Length Z O. D. J I.D. (.F" --- Material 512.e...l Liner — Other — DAMP RECOV. BLOWS, SYM SURFACE CONDITION: GraSS TYPE FT/FT per 6' SOIL/ROCK DESCRIPTION SOIL VAPOR PIOO eoO DO HS C p '4 8.215 4? e 0 8' o IV NO RE coy EV( 6 16, 1 2. 4v 14 IS ‘5- 24! /A vgered -to 141 1' 1(5.14! - Cot SILT ANb CLAY BYow,,,`J, rat- sod t.0CATl0N SKETCH SS 3 14/1-0 16' 14' -to 15.3' (SAND AND GRAVEL Brovw Yne.d deves_ , SOWio.. SUM.— Up -10 Z - 1v\ CIA d; ocwletev -t>acp SO if C-Ioy WEB;---- -- = 15 03/ 1ct. IC.0' NO RECoVER. io t6.0/1-0 tq,o. SlIND AND GIRAVEL, 3YOWt'1 EOYYte StpN,2_ d,comitvr ,1-ra cg. il-r.(C!t cla,,, S S 4 19 -to zt'--�- Ick.o "to 20.5' SAND AND A'f-L UYowy1 , W0eJ d e ISQ.. sO'MR. slew_ See LOG STATUS DENSITY: GRANULAR: COHESIVE: 0-10 Loose 0-4 Soft 10-30 Med Demo 4-8 Med Stiff 30-50 Dense 8-15 Stiff >50 Very Dense 15-30 Very Stiff !:,1..1MINARY - FINAL PROPORTIONS: 0 -lox 10-20% 20-35X 35-50X Trace Little Some And REMARKS WEATHER 60F Svrrvy..,� t'.��I Envlro�r oup ted p Centenntp,. Ceti eCia CLIENT LL MAY.Y. I\ior1 l Tericck PROJECT LOCA 1011 SOY, CO BOREHOLE LOG Z v PROJECT NO. LF O 53 K PAGE .3 OF . NORTH DRILLER\LL(NS ENGINEERS 1NC, DATE START 4/1 a-4°°7 EAST RIG C. ME- 3-5 DATE FINISH 4A 2 A0o7- cm) Ei.EV BITSg.25y 11 -S. q . ( FLUIDS •-- TOTAL DEPTH ®.3 TOC ELEV. LOGGED BY ChArcevs S - WATER DEPTH 14 SAMPLE TYPES: CT Cuttings WS Wash SS Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS:ej22 Length 2 ., Material A 0.D. 2' Liner —' 1.D. I.3 " Other 1,EPTII (FT.) BIT CG ASIN SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6' SYM SURFACE CONDITION: I IAiSS PSoHVFOR SOIL/ROCK DESCRIPTION 50 Hs Core S^ x —20 i- _2 I ' 22 23 24425 25 26 272Ss.2' 72 1 '3o ' N R.25 H. �:D. 12 SO �y up "0 2- i vac\„ d to wee it.rr t wa.. , Si It , ' t c -e, c -d o�y . W F"�'_ 70.c; to 21.of MO RECOV.GRk Au3ere.d Io 24/ 2 1.0f 'IP 24. 0' - CUtttr SAND I ND G RA\JE L . -BYowvni� red by o `y---- so ._ s1ov1, up -tom - iwGV CJt;c5VhQkR - . WL-'T f1' 2 �f 24- Z2 40 35 3 I ss 5 24'1.0 -2.6 24.0-(a X5.8 S��1D AN IJGRAV L. - Brow, 1-... redbrowt l , v�.ry jd€ssQ, Some sio o Uf lb 2- 1sdA ci i 0.rvl a-.1. , W PT 2_ -t-O 26.0' IVo CECovERi • AuTerVd -to 29' .2. .o i028.0 - C Yt(Ir, - SAND AND G,PA'J L. _ 3, -1,,,,k ` -i-0 redbrrown som, 9 tOh e S up t0 2- i+tiCtn oliAleV-t j' S ( �-O 2.O'12_ Culi, SIL1 sToNE. 2 ov.nn ( � 1�- so -tramc_(c,� WET - sS 6 2q/ -1-a 30,3' LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER U, ��w A Qv_" �', GRANULAR: 0-10 Loose 10-30 Med Dense 30-50 Dense 3)50 0— Very Dense COHESIVE: 0-4 Soft 4-8 Med Stiff 6-15 Stiff 15-30 Very Stiff 0 -LOX Trace 10-200 Little 20-357 Some 35-50X. And (� 60 r U 'iew / LOG STATUS: PRELIMINARY __._. _ ...____. FINAL: t/ EnviroGroup t-imiLed SIN Can Connlet. C..olOreao CLIENT LafG`r t iVoirT Hrnerica PROJECT LOCATIO W iYlci 'oY . Cb PROJECT NO. (.F'-OS3g a BOREHOLE LOG NORTH EAST CRD ELEV. TOC ELEV SAMPLE TYPES: CT Cuttings SS Split Spoon DC Dry Core Other. NH N0. PAGE 4 OF DATE START 443/iv'a - DATE FINISH 4/672.- 9 - DRILLER ✓1MLL'NQ° EN(NEEQS INC, RIG CM'E 45 BlT5g.2) RlI.S.i.IFLUIDS LOGGED BY ChArcevt WS Wash NX NX Core CS Continuous Sampler SAMPLER SPECIFICATIONS: Length 2 i5 O. D. 2 I.E. TOTAL DEPTH 30.3 WATER DEPTH , Material � 1 Liner '--- Other — UEPTH i� ) HIT CASING SAMP NO. SAMP TIP RECOV. FT/FT BLOWS per s" 5Yt� SURFACE CONDITION: VAS'S SOIL VAPOR SOIL/ROCK DESCRIPTION BOO r DO ca 30 .3 S H.S,A 42S I.D. �F ENiJ AID 29.0' :-T- SILT STONE. , BYo r�^ • bM Otto VeYy S 1�' IFi�"sz. cla s�1vt_ `�r ra.c sowtdt' . Sr0 wadh t. Frrter sam a au • to -E.41 fa 2q - S' IH sfali rCGk.; br4 Lwail -] --(0,4-"s 2" PVC )o c.re.el,t Coo ow.d Lock- -' CQ:Kc R g ¢r ' 3 b )°1. i ' CoOtc . .c O 'Cre.c 11.2 -62-9.2 14, (3.z 4z.. cal, Z Cot P 2,1:2' —2.9.s' ri1 f A $oer J 1� -Ib -1,,,,,,,,q 6 bot S' So 4 bay Con, CY'.e t a.. I b oo e - Inr.ATIIIM Qin., tom GRANULAR: 0-10 Loose 10-30 Med Dense 30 —so Dense >50 Very Dense COHESIVE: 0-4 Soft 4-S Med Stiff 8-15 Stiff 15-30 Very Stiff PROPORTIONS: 0-10X 10-20X 20-95X. 3,50X 'heed Little Some And REMARKS/WEATHER 30F S-uvw1/47 LOG STATUS. / ` PRELIMINARY. FINAL:V 1K't EnviroGrotlp E.imit:c:cl '� ConCorYl�yf,Colprd.cN.1 PROJECT LOCATIo hs sor , 0.0 PROJECT NO. ... LF-053i' li NORTH - ...._,.1,1,, rAt. + OF DRILLER 11.\LLtNa ENC�INEERs INC. DATE START 4A V20ei • r.,A'•'' RIG C M E - -3 `j DATE FINISH 4/tg /2.0.7- `, ORO ELEV I:, BJTS R.2S"l-I.S..ra,I FLUIDS TOTAL DEPTH 31 'MC ELEV LOGGED BY Chq r0 �N � • A / WATER DEPTH I'� SAMPLE TYPES: C1' Cuttings WS Wash Split Spoon NX NX Core I. ?C Dry Core CS Continuous Sampler Other SAMPLER SPEC,JFICATIONS: Length Dgth z;'5 Material stee..1 I.D. t.6 Liner _� Othe......._=_..- [DEPTH (FT? BIT CASING SAMP NO SAMP TYPE RECOV. FT/FT BLOWS per 6' SYM SURFACE CONDITION: t� t- SS SOIL VAPOR PiFIDE] BC Hs SOIL/ROCK DESCRIPTION -0 1 k _ 2 �y. = -J C • g • .._(LiSS . Core -S ru 4•�' 3.D. - — - - - eyed to 4' r.Ak2 0 `to 4.0 i V1 vt . S(Li ANb CLAY = Bra,...., , I i flirt._ 'A,,,,c1 I i-ii (,rt.. gYavtrl -track. YBn' U, rno itfi, 8c.;to 6 S S lg' � 24M 2 3 3 4 4.0 0 5,,..:�(NE SANG $Yowvt ©OSL /— SowIQ StFt ,,So ceky we.t ( ?u, 50,), wcKeY 1 S,S' l0 6.o' NO . FINE CAND sow,t_m It , s , ,�i we.i i, o'ta `i.o' � Ctrl•; V,„ _ SILT AND CLA_V( _ z. 9' to It . ss 16" �y ?4. 6 1Z - FlM �l.o to 1p_3' To I''1�Diu SANDI = TYf� dev,s�. , Some.c subs v Q `�o z-��n-Dowry C.\ d; f U SPI0ter , TDo i p _'_nCATION SKETCH DENSITY- PROPORTIONS: REMARKS/WEATHER 30f S UVo (/ SeeLoose V e e ¶ `_' V 1 GRANULAR: 10-30 led Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 Mod suit 8-15 Stiff 15-30 Very Stiff 0-10X Trace 10-205 CLUe 20-355 Some 35-505 And I.0(; STATUS. r•I.ELIM!NARY FINAL BOREHOLE LOG BH NO 3 ErwiroGroup Limited pi Gmntenraa,, Co,orefoo CLIENT Lottoor America - PROJECT LOCATIO wI,Cor� CO PROJECT NC LF-053g NORTH LAST 1LCRD ELEV. t TOC ELEV. SAMPLE TYPES: �Cuttings (SS)Split Spoon 11)YE Dry Core Lher. BOREHOLE LOG DRILLER ✓i iLL`Ng E1 'NEEQS (NC, RIG CME �5 BITS g.2S"I-).S, A,l FLUIDS LOGGED BY Cho.r©ev WS Wash NX NX Core CS Continuous Sampler (DEPTH J(PT) 10 ^r 111 CIS -16 BIT CASING .d $.25 H.S,A s. BH NO. 3 PAGE Z OF 4 DATE START '¢A0 -0o? DATE FINISH 4/16/L614)� TOTAL DEPTH 311 WATER DEPTH 4 - SAMPLER SPECIFICATIONS: Length Z.' D. �.s—'_ I.D. 12 ee .. Material 512-x.1 Liner Other DAMP DAMP RECOV. BLOWS SURFACE CONDITION: ara.SS NO. TYPE FT/FT per 6' SYM 20 SOIL/ROCK DESCRIPTION SOIL VAPOR PING MD Jbe3' 10 tl.o' No REcovER`‘ l h� b Recl bYOwV, 1r`1ed a2v,S2 i�TaC.rt. 2¢N i S;1% W Qt . 5.3 to 16_o' NO RI✓C0 ER`f 4uoere.d io Ia' 16'.0 to (- CAN', — SAIv17 Akfb (;RAVEL ,--lace O ' Wa.t A u5e'eci lb (4 ]i.0 to 14.0' - Cut1;,g - SAND 4ND QRAV5L. BYowv) Core SS 3 14' to tb' 14.01lo 15,3' SAND AND GRAVSL_ SS Iq.o -fo 20.5 4 IQ to 2.1 SAND AMb CRAWL . G2 Some stmet Uib 2- 7 „11 di avrle�R , h ElLO. 5 . �N2 J ATION SKETCH DENSITY: Q e P i C?A,1/4 10-30 lied Denim 4-8 ::t e 10-201tttlemitt 20-35X Se o Fy Stilt 35-50X And LOG STATUS: PRELIMINARY: PROPORTIONS: REMARKS WEATHER GRANULAR: COHESIVE: 0-10 Loose 0-4 Soft 0-107. Trace FINAL: �y+l+ Eny.:7,=oup Limited Cante.nnidl, COlOrOdO CLIENT 1.a "ale %Vor , 4wterico, PROJECT LOCATION Wir Sort CO PROJECT NO. Al' -- O 0 s 1S PAGE "' OF NORTH DRILLER\LL{NQ ENCOINEERS INC, DATE START 4/IS/2C°7 EAST RIG C_ME 45 DATE FINISH 4-/1g/LC°3- CRD ELEV HITS2.25"H.S. A.1FLUIDS `" TOTAL DEPTH 3 V TOC ELEV LOGGED BY Chcroev, S. WATER DEPTH (4- i SAMPLE TYPES: CT Cuttings WS Wash 8 , SS Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS: Length 2 . St 2R. 1 g � Material O.D. 2' Liner -- I.D. I u •'3 Other — -- DEPTH (FT.) r HIT CASING DAMP NO. SAME' TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: GrassSOIL ProOvnop SOIL/ROCK DESCRIPTION BO Os Core Y20 = 1) • �Z ?f.1- 2S $ zq 30 - 5H g.2ave-R. HS.A x+.25 I.D. 5O%, zo.S' io 2(.o No RSCOVcR,`i, ....... Au3ereJ *O 24.' 21.oi o24.o - e.,�i�nj - sAND AND ...... GRflV EL . 3,0w� o . sme Up 1`YaC.a-- S ;tfi sS 5 24' tm 2 / ..- y Z 24-" Z5 32 3S 3(5�6, 24.o'to2S,'' SAND AND GRAVE , _. BYowo ? &&4S.2 so, -(O- , QA15VIILS up -to z- [0c1., 4;0,,,,A-o- fira.CK sit}. 2 5-x' -to 26.o/ N© RECpv 6.R`( ..... .. 2(a.o' jo29.o _• Cvi}Tv,- BAND AND GRAD EL s0,►e`��4es u "to __ - 2-„',cln d;osw,ekec 'lraru. si1- SS 6 2cl' k0 31' Ili' �4y b 12• 201.0/ to Bo/ SILT STok1E. _ are - . _. \a., sfi� sorl.a_ C.lovy ,+Ya.CIL• SOWA . 431.A117 vvceiterejwc . _ LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER UeQ d7I GRANULAR: 0-10 Loose 10-30 Mad Dense 30-60 Dense >50 Very Dense COHESIVE 0-4 Solt 4-e tomStiff 8-16 SUM 15-30 very MI 0-10X Trace 10-2ox LHti. 20-36X Some 35-50Z And -40 f k..Pir'1(N�/ BOREHOLE LOG BHN0. 3 LOC STATUS. PRELIMINARY. _ •_ FINAL Yf EnviroGroup Limited 1 Centennial, Colorsiao CLIENT trafGoT�j Q 1VoTM Hrnerico. PROJECT LOCATIO� W �r, Sor, , Co PROJECT NO. t, h - V 313 PAGE 4 OF '`I' NORTH �t� DRILLER Dr4LLIN�si EN1lNEERs INC. DATE START 44e/2.009- EAST RIG COTE. E 7.5 DATE FINISH 44€I�OL_ `31 GRD ELEV. BITS2.2O° Ii .S. Ad FLUIDS --TOTAL DEPTH t TOC ELEV. LOGGED BY nieNroevt . S WATER DEPTH 14/ SAMPLE TYPES: CT Cuttings WS Wash SS Split Spoon NX NX Core ' DC Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS: Length 2 • steel ri errial 0.D. 7' I.D. 1.3.Other -- , DEPTH j, (FT ) SIT CI31'NC SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: GrQ9S rsoQy�soxp SOIL/ROCK DESCRIPTION so is sera ~� X31 Zb 3C� 3O_ol"to 3Lc( MO (kEOOv.E•RN ,25 H.S,A 1.D, END ofp0REH' i /1 ne.r.J to 31• __ END oF $o4Ettot,C. _ ..... ..._ nOVl1tOYtv't \ IQQi 1W:1..11Otlov 2' PV C. 10 -#ooh' CCYQ12N ._ i'1 W — 3 C.,5;,3 4 ►O4L Cc,f 47 1?'s 3�7-"-- _ r4e.>; —3 b0 20.9.E Cc„nc€. to 0 fo tkYeevl 20.3/ to 30.3' BCv,tov,:lte c1,ig 4I -TO Co'? 30<1*r1_o31.o T;Itel sO N1 Ig.SJl sated 3 ba s -8 e,41, uT 2 a;;vp 6.6 boo CAhCY>t.ls 2 bo' S LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER ` aQ er 1) �� GRANULAR: 0-10 t.00ia t0 —so the Dania 30-60 Donee >60 Very Derma COHESIVE: 0-4 Soft 4-8 Lad Stiff 8-16 Stiff IS -30 Very Stiff 0-10X 'race to —cos Liu'. eo-355 Some 35-507, And �© I �,-,'‘,.7 BOREHOLE LOG BH NO. 3 LOC STATUS. PRELIMINARY. FINAL; t/ E�vtroGr-oup Limirgct p CansrunntntCotorbrio CLIENT _Lc (Ot9 .2 (\kith America - PROJECT LOCATIO I . 1 JiN c tJm r CO PROJECT NO L. F - O 5 3_$ NORTI1 DRILLER MLLtNg ENC->1INEeRS INC. DATE START 4 /t /zoo EAST RIG C M E - 75 DATE FINISH 4/I g /2007 G RD ELEV. BITS ge2S' H • S••A• I FLUIDS TOTAL DEPTH / 3. 7' 9'OC ELEV. L LOGGED BY Cl-la. r©el/, g WATER DEPTH 4' BOREHOLE LOG A�dc1�o,Yd BH NO. 4 - PAGE OF 7 - SAMPLE TYPES: C ' Cuttings WS Wash Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other:.. DEPTH (FT.) BIT CASING DAMP NO. DAMP RECOV. BLOWS SYM TYPE FT/FT per 6" SOIL/ROCK DESCRIPTION SAMPLER SPEC)FICATIONS: Length Z;S O.D. Z LD. la Material ctj'( Liner Other - SURFACE CONDITION: Gras SS SOIL VAPOR, PlaD FID❑ BO HS Core �4 4.7s0 3.D. 10N 6 — 12 Z4" t 2 12 u2k.re.3 +0 4- O Jr. 4.o — QA;r,g - CIL1 AND Cam'{ - $YO\h +T EN EH. YeIA1Q . (YIeficI.t as i 4' 4.o' Ito 4:S' 614AV t_ , $NOsNh, ,',e ) Cl eY,S L , ttO5C2 Sowwd -YOLC2 CAD,,/ . Wei 4.$' -l0 6.0 No 2E co yr R`( /U3QTea "to R' tu_o'1lO q,©' °AIN L , `BYow, se".p_ ci • sow, sAme. up •to 2 -►,cti, d� o w, el e� tYacQ 31t , tYa.C .,e- 4crY , t\I et. 7e 5 q_ot10 Il.o' SAND AND GRAVEL .`6Nro , `to red bro`^^ s c evIge. , `IYOt I e,lfi 2�r IS LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER GRANULAR: COHESIVE: T SQQ ` 1O,V\ 0-10 taose 10 —SO Med Dense 0-4 Soft 4—B Med Stiff 0-10R 10-20Z Trace Little , , Suv\�►�y 30-50 Dense 6-15 Stiff 20-35R Some >50 Very Dense 15-30 Very Stiff 35-502. And LOG STATUS: PRELIMINARY: - FINAL Enviro.roue Limirac3 IIL'tli C,enre+nni®I, Cnicx�raG1r.� CLIENT -L OtY e. Not America.. PROJECT L0CATI0O PROJECT NO. LF -O53g NORTH DRILLER ✓r\LL(N, ENC�(NEERS INC. DATE START 4/le /2004• EAST RIO C 1`'1 rj DATE FINISH 4A S /2-003ERD ELEV. BITS g•2S�fH. A,I FLUIDS -^- TOTAL DEPTH 13. TOC ELEV IS_. LOGGED BY Charcev► �. WATER DEPTH 4 SAMPLE TYPES: e4.,,,-1,...„ WS Wash NX NX Core Dry Core CS Continuous Sampler Other:.- ..... SAMPLER SPECIFICATIONS: Length 2 .5 ' MaterialSt2 e, S.D. 2"' Liner I.D. I -.4" Other - DEPTH (FT ) BIT CASING SAMP NO SAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: =f•ra-SS MO noso1L VAPOR SOIL/ROCK DESCRIPTION 50 HS Core - 10 -,1 —12 13 = -) 4 _ —IS , 6 ;1l —1$ 19 FL 20 • •-•- -• - .„ g,25 li.s,A 4 2s L p - 1� Aueria "to I2.' II-o'to 12.0 - Cutivtq - GILT. BYowv\ �if p ?fl 20 42 to,,1z..o So tu. std , S 0,,,,,Y 3,rave.A . W' * $ S 3 12( 0 14-/ r to 13.3' U--TS-1-O. Ng . Grk.t _ vfay S't� `f , *ace_ e.tol , L ki o i weaitleiR. J • Wei 13.31+ i3.�/ N6 REC.otEWI E.Ni7 Cc 'Bout.Lto1Q_ Row,i0t- n w e U1 3,, siotl1A` a t.+ C4j op L) .V? 2 ipV' .4 --Coot sCY•Q.2AV0 Cass h o lock. nW - 4 cap R,skr — 3 +O 43/ 3 / Co, CY'4 4 o +0 21 saw 4.7' to 11.x.1 1Cvt`aoSL. 842_2' it) 4( 09) 11.E1{0 12_0' Gi1}Rr En,e 1 4' oto 13.3� LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER Zee.. GRANULAR: 0-10 Loose 1D-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 lied Stiff 0-15 Stiff 15-30 Very Stiff 0-107. Trace 10-20% Little 20-357. Some 35-507. And IO J ov-7 BOREHOLE LOG BH NO. 2-- _ OF 2. LOG STATUS. P'RELIMINARY. _ . FINAL: EnviroGroup Lim ite G Canconniel, Coioreoo CLIENT _I-ctf.071.e, NorV #imeyicc0.. PROJECT LOCATIO I W i,t Sort CO PROJECT NO. L F- O 5 BOREHOLE LOG BH NO. 5 NORTH PAGE 1' OF '`'- DRILLER JILL,Nis° ERNC-;\NEEpS INC. DATE START 'VII 4.9 "AS RIG C__' - `E 45 DATE FINISH 4M/zoo- CRD PI..EV BlTS2.7(6'11 .S. A.1 FLUIDS - TOTAL DEPTH 31 ' i TOC ELEV. LOGGED BY Cho.r©e►n s► WATER DEPTH 14' ri SAMPLE TYPES: Cuttings WS Wash SS Split Spoon HX TI;sore Dry Care CS Continuous Sampler Other SAMPLER SPECIFICATIONS: ' �j QQ, V Material �_ Dgth Liner 1.D 1.2 " Other ___.__..—__�_�__ DEPTH (FT.) ° BIT CASING DAMP NO. SAMP TYPE R5000. FT/FT BLOWS per 6.. SYM SURFACE CONDITION: G'raSS Sou. VAPOR MO POD 8C NS Core SOIL/ROCK DESCRIPTION j a_ � ? E L 4 �2.0 F E' C - ,4 'i.--.9 :724 -1D . 8 25 NSA ,25 Auq•ere., t0 4/ o to 4,o - C-hvlg - 5(L7 ANOCL.A't, ""2 Bxowv, ,1l+ii.& co+ n . l'+f11.)._ 9Yove ss 1 4/ to 4,/ ii - 24-" 4 4 4 4 4. ©i to ' S 1 LT r COWL. sannd line- c1a Mo lgt --- .2'i a 6.d NO RE.cO v "R`( A vgerecl to q 6.011b9.0/ SILT. EYowti1 y vr56 0co , little. day . Mo;%t r• -- sSz g1fb%1 1 'r 2Q �� r 4 f r • o to lo,� C1-Py' Blro wv\ 1 i 14_ sit I:ill . sot' moist LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER oe Y1d1v\ GRANULAR: 0-10 Loose 10-30 Med Dense 30-50 Dense s50 Very Dense COHESIVE: 0-4 Soft 4-8 Med Stiff 8-15 Stitt 15-39 Very Stiff 0-107 Tr.. 10-207. Little eo-35X Some 35-50X And r 50 �tnd (� 7 S V V,N\y / LOG STATUS PRELIMINARY FINAL ✓ lI ErwiroGroup Limited C3or lietnrltHt. CaiorC1C 0 CLIENT.La-6Ye''vost America.. BOREHOLE LOG PROJECT LOCATIO`fN1 WinciE CO PROJECT NO. L - 0 5 3 g - NORTH DRILLER \L11Ne E.N1kNEERSINC, DATE START 4/19 /Zoo? •r.:AST RIG C NI E 45 DATE FINISH 4/19 /20:27- GRO ELEV. BITSg.2S"H., A.IFLUIDS '- TOTAL DEPTH 3{,' TOC ELEV. LOGGED BY ChAr©ev, Sc WATER DEPTH 14' SAMPLE TYPES: Cuttings WS Wash (5S) Split Spoon LT( NX Core bC` Dry Core CS Continuous Sampler Other. _ . SAMPLER SPECIFICATIONS: Length Z. .5' Material tQ�1 O.D. Z" Liner I.D. 1.7' Other f _ - DEPTH (FT) BIT CASING DAMP NO. RAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: rGLSS SOIL VAPOR P.0 i7DQ SOIL/ROCK DESCRIPTION 50 11S Core 7 Pp _ -12 -13 ,---.-(4 t. =1 S 16 ,t1 = E--t9SS 'F.._ _ �Q •u g25 si 1� q 1n.3-'ta .i.o' NO . ...vFR`i Au u rna "n 14' 11.0"O 14,o' - C-vihnc- CLA'f . BeovAii ti1a.. sill- tt 1,L so,,J, V41of c L Ss 3 14�to16' f' 17 ----- M 2� c l0 -+ to 1 '�0 15.o SAND 4 o D AN7 GRAVEL. `�irovwt Yvv,4 dehse_ *rata.. a.. sits" 'T rac caw/. , W e� . I5.C�'-1-> l6_O' NO R covERY A UgeTQd -to lc( _ 16.0'+0 19.o - C.,_*;,.., - SAND 4Nr) GRAV2L teat c �i1'f' -r-rac..2- of ' Iq' -to 21/ ... 22' y T4 12 24 Iq.o'-toao.e.' SAND AP.D GRAVED . BYow1A V QN y deNS2 tircoCo. S ll- , iyaCQ clay _ Wc+ LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER 2.-.2(L. 'P1 Cl" GRANULAR: 0-10 Loose 10-30 Sled Dense 30-50 n.... >50 Very Dense COHESIVE: 0-4 Solt 4-8 Red Stiff a-15 scut 15-30 Very Stiff 0-10X grace 10-20X Little 20-35X some 35-507. And ( ,' 5O F `o 1 IV\) 1 0 UVIvly BH NO. 5 I.00. STATUS Pith LIMINARY. FINAL: Ij EnviroGroup l-irnited 1 Contenniel. Coiorcio CLIENT Lafoo A.IvorTh Nmertcca, PROJECT LOCATION —W iyi c1 So r . CO PROJECT NO. L F - O 5 BOREHOLE LOG DRILLER \L1IN4 EN%1NEERS INC. RIG c_ME 3-5 RITS a .Z 54 H -I .S. A ,1 FLUIDS HH NO. PAGE 3 OF DATE START 44 R/zoo7" DATE FINISH 4/1q/v,03- TOTAL DEPTH 31� SS Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other - 0.D. 2' Liner - 1.D. 1.1 g Other — DEPTH (FT) BIT Cii-gik SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6" .„„ .5'. SURFACE CONDITION: h.SS SOIL VAPOR .00 F.0 SO1L/ROCK DESCRIPTION 110 IIS Core 2 2 • • • r siq e ii-u3ereci to 2-111 • s till -1g, et.o,p_2tve7t2. Qs 6 2cl/to 31/ DENSITY: GRANULAR: o -lo Loose 10-30 lied Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 lied Stiff 8-15 Stiff 15-30 Very SU11 PROPORTIONS: 0-10r. 10-2. 20-367. 35-60% Trace Illtle Some And REMARKS/WEATHER 50F w;v,dY LOG STATUS. PRELIMINARY: FINAL EnviroGraup Limited CLIENT_tafctrNorT America BOREHOLE LOG PROJECT LOCATIOlI Winds©Y, CO HH NO. .7 PROJECT NO. _ F-OS3$ PAGE _OF 4' NORTH DRILLER ✓ 1U INa ENCI' 1NEERS INC. DATE START 4 A 2003. EAST RIG C -ME 45 - DATE FINISH 4-49A 007 GRD EI.F.V BITS93S'Hj H.S. A.1FLUIDS --- TOTAL DEPTH 3 1 '1 TOC ELF.V LOGGED SY Chmr©ev S. WATER DEPTH 14 ' SAMPLE TYPES: CT Cuttings WS Wash SS Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other SAMPLER SPECIFICATIONS: Length 2 • 1 Material St'e'p' 1 0.5. 20 Liner '-' w F.D. 1..3 Other -- -- DEPTH (FT.) BIT CASING SAM. N0. TAMP TYPE RECOV. FT/FT per 6' per 6" SYM /� SURFACE CONDITION: �7II G2 SS SOIL VAPOR Prop flop SOIL/ROCK DESCRIPTION SC AS Cora u 31 , 8?5 H.S,A, 435* I.D. 50 We,*• 30.2' "1o31.d No RE.C.oV5Q- - CN./D cA, HOR.i oL-6.- A O3eel ed t0 2\.>,'._ Acid Sovv,cl to 2c1..0' - Ey:\ d o -e box -4113o\ 5,— _......... (11ov\1ter ing well DAsUlloit(con 24 PVC 1 © - 4cV Saes?), I IMw 5 ... casihc .4 ,4 lock. Risk,- — to Ige9' Coo,clretc, O'to 3 ... Sc-e.A lge-i'io z$.if 1e4o41A dA f 3f+otif C..? Z $ .9'k o2 q . o' ,c11 -to SowJ 1-10 31,( ' f I UHA ac,—,) 4 19O.O,s eevA0 ,AlL- 6.5 1.a s - _ C.Ie rtCY Av. 'Z- ‘,,,,,,55 LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER eQ ?10. GRANULAR: 0-10 Loose 10-30 Med Dense 30-60 Dense >50 Very Donee COHESIVE: 0-4 Soil 4-8 Med SUff 8-16 St111 15-30 Very SUfi 0-109. Trace 10-20X Uttle 20-35X Some 35 -SOX And 5 O F � `Av t ty J gUVVA/ LOG STATUS: PRELIMINARY. . FINAL: EnviroGroup Liminad CentanNet, Colordcao CLIENT La L e' �oT`L Amer+ca. PROJECT LOCATION W R d Sow CO PROJECT E -0538 NORTH EAST GRD ELEV. TOC ELEV. BOREHOLE nfLOG &att'ict/QA DRILLER ✓tr`LL(NEN) 0tNEEQS INC, RIG CME_-�5 HITS R,2S" t•S_ J FLUIDS LOGGED NY CharoeD S BH NO. 6 PAGE I OF 3 DATE START 4/(9 /ZC3a- DATE FINISH 4/19 /2007 TOTAL DEPTH IS) WATER DEPTH 9' `AMPLE TYPES. C' Cuttings Split Spoon DC Dry Core Other: WS Wash NX NX Core CS Continuous Sampler SAMPLER SPEC)FICATIONS: Length Z-5 all 1" I.D. 1.3 Material Ste'el Liner Other --- DEPTH (PT) BIT CASING RAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: Gm SS SOIL/ROCK DESCRIPTION SOIL VAPOR PIO0 PM t1s Core 4 zs IU_ 2 2. 2 2 A u er&I. 0 lo 45 o - C 0-tL- - SILT AND CLAY D0.Y1e brow., 1Intl,¢.. sow s tr«CA. toots , rioiSi- SS 4'to6' 4.E/ to 5. G' CLA`i , BYO,o,, \ i s4 -t, m U ; sit -1 0 6.01 Mo RECovs{Z`t Au vs,2d 6.ot to 9 .o' CLA`S so,d l,-1t1,a s• 1� Mt,� si` S2 9o((/ `O'0tco! 3 2_ SAND AND GRAVEL , 13ro,,.A., vog,s I i lsz c brt. 2 - ► "CIA d; 0 0 11- "tax (g_ G )1 f 'brine.,:. Cl V\1,a LOCATION SKETCH SER. Pte \ DENSITY: GRANULAR: 0-10 Loose 10-30 Mad Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 Med Stiff 8-16 Stiff 15-30 Very Stiff PROPORTIONS: 0-10% Trace 10-20% Little 20-35.% Some 36-50% And REMARKS/WEATHER 50 v.I ,,J'� SVVW\ LOG STATUS. PRELIMINARY:,_,___.___-___._._. FINAL arwiroaroup Limitad Contennicst Ccacm-eioo CLIENT L -Lx -&Y e. IVOY�t\ 01Yrtertca PROJECT LOCATIO W ivi d sor. CO PROJECT NO. L F- 053g 3 g NORTH ::AS: G RD ELEV. TOC ELEV SAMPLE TYPES: Cuttings SS Split Spoon Dry Core Other: BOREHOLE LOG DI -I NO. 6 PAGE 2- OF DRILLER afNILLINa ENCzINEcRs INC. DATE START 4/tq /2003" RIG CM E 5 DATE FINISH 44 q /2,40-3 BITS S.2S"1-(.S. A., FLUIDS -- TOTAL DEPTH 2 S_5 LOGGED BY Charoev, S. WATER DEPTH 9 WS Wash NX NX Core CS Continuous Sampler SAMPLER SPECIFICATIONS: Length Z .5 O. D. 2." I.D. Material Stez4 Liner — Other DEPTH (FT) CASING DAMP NO. SAMP TYPE RECOV. FT/FT Blows SYM per B" SURFACE CONDITION: a•ra-SS SOIL VAPOR PID0 PM SOIL/ROCK DESCRIPTION eo HS Core =11 --12 =1� =14 -1$ =l9 20 4.25 11.SA. 4 2c" CD 3 (5 10.21 tb tl.oi No REc 'i c 144 24" 5 10 20 A'o eved to 14' 11 .dto 140' -- CUlj;l•.q — SAND AN d - aRAV F L . {brow,, , sore si-em.s. - = p 10 z- iv,c1, ct;,,,,,,ile1CY bats._. C\ 1- ,trod". R CAC w e. -k._ 7+p ES 3 14' 16' 14.o'i515.2' SAND AND GIRANE-L,- )tOl A4 VYIEG clQtoEl 5DW1Q acmes ti `lo 2.--1,e-V, cluot, of., ` YcacsL �(t grace. W ,2+. 15.2.'to160 N0 4. cov>=R`f 16.0/1•019.0 - SAND Ak 6RAVFL , so e R otoh\RE - 2- IYICY\ d\ 01Q P.,1c firac..., s i\1 c\...y . Ss4 10t021' q.0/to2.o.z' QAN5 AND ap.A\IFL C - vod �kuSQ, SOo-n Stcrit .s up to 2- Tndln dr LOCATION SKETCH VQO DENSITY: GRANULAR: 0-10 Loose 10-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 Med Stiff 8-15 Stiff 15-30 very Stiff PROPORTIONS: 0-10a Trece 10-207. Little 20-357. Some 35-507. And REMARKS/WEATHER SO W,v,d‘f svv\v\y :.oc STATUS PRELIMINARY. FINAL it+l EnviroGroup Limited C oarmennim, coioredo CLIENT taTCAVIR. NOMNOMA IiTericck, PROJECT LOCATION V01118 d S� CO BOREHOLE LOG 6 PROJECT NO.. Fi ^ U 5 "'. Alt_ PAGE _? OF��.._-..__.._. NORTH DRILLER DILLIN4 ENC2MNEERS INC, DATE START 4/i 1/ o. EAST RIG CPE 45 DATE FINISH 4/ICf /2oo7' G RD ELEV. BITS9.75' H ..S. A.1 FLUIDS - TOTAL DEPTH 25.3 / TOC ELEV LOGGED BY Charce►n S. WATER DEPTH Q' SAMPLE TYPES. CT Cuttings WS Wash SS Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other:_ SAMPLER SPECIFICATIONS: } Length 2 ., material ,�.Q'>2,1 O.D2' Liner - 1.D. I •.3 " Other * DEPTH (FT) BIT CASING DAMP NO. DAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: l•> RS PSQVAPOR DO❑ SOIL/ROCK DESCRIPTION BO Hs Core -2o ti z :-.-27.. 24S� . (� -LOCATION y g 25 H SA, 42s 7 D. L50�... , LO 3° �rct.C.2 Sit "ii- Cit50 \N AL i 20.2' fia 21 _o' MO AG '\JE9 f A u8RX.za lo 24-'• - SAND AND 21,o'' o24._o' - CUBi 5rc� - RA VF L, . IYo4.n/N `kr . S�� 1� Ilra c a. clay. . U.I a + _ 5 Z..4-' to 26. / 10 ?_5 .50 4, 24.o'toZ5 3' SiL"r5-TONE Grszyr vO. ki�-4 1;44iz. So,w,a `f'ra..C..s:_. I CAol , w s a �� Bevtithilo Co, ENO C' -�� 6a c Yet , BoR z s 6,a5 2- lo c 1 trx„-�. 5 !END OF -$O 1-I DL -E.- ... - z r 'eve. 10-4,4- SCYVS.ea+n Mw - 6 cc.c;r,q LOCk J •- ^ 7RQP — 3 to n:4' 3' CaAure.f a_ O fo 3 = 5:C:( ('C'.", 12,-' 3i ' 10 7a9'' 171r 01ii (,4 C 121_.3 to 1Z.' ' • dap z3.::?' -1,.1.4 I Fii'LCh'CwVt i2'+U 25. SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER V -e� 1, A v\ 1 GRANULAR: 0 -SO Loose 10-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Solt 4-e Med :n 8-15 Stiff 15-30 Very Stiff 0 -to% Trace 10-20% Little 20-35% Some 35-507. And r� , �,v� J�"' . i t wl h Q� LOG STATUS PRELIMINARY: FINAL: enviroGroup Limited Centonnlel. color -moo CLIENT_ -f°`r Z N°4^ Arnepca- BOREHOLE LOG PROJECT LOCATIO11Inlivl I r _CO PROJECT NO. ._LF -O53$ /Iva RId qTi BH NO. PAGE -I____ OF 2 - NORTH EAST DRILLER ILLIN C EN(INEC2S INC. DATE START / C /2007 RIG CME.---5 DATE FINISH 4/I Zoe GRD ELEV. BITS g.2S a H...A.I FLUIDS TOTAL DEPTH 16' TOC ELEV LOGGED BY Ch,Ar©eve S. WATER DEPTH Ct / SAMPLE TYPES: C Cuttings WS Wash Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other...._.___. SAMPLER SPECIFICATIONS: Length _Z -5 Material Stepl co..2" Liner _ Other I.D. LS - DEPTH (FT) BIT CASING SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: Grass SS 901E VAPOR PI[Q FID ❑ SOIL/ROCK DESCRIPTION SC HS Core — k 4 104' 0-4.0'; cullil - SILT AM 1-tA`l__ ])cm t bYo1wvo 11�c&c.o EUo a -TT +Para Yootl . oi0 5t gZS` 7.— E1.S.A -:.4. SS 1 4/-10 6' = AI S f, 4 zs --- Z 1� l SovnQ , `VroktL Sill PI O;S\- __ _9 - 10 J..D. --- . -- 24-0 Z Z r 5 # o 6 . o' iJ © REco v �.R`( -- Av�exe. a -t© 9' 6.o'in ck_o CLAN , `Biros,,,, sovwt .. _ s 1 racu.. o4 , (10-‘5"t" .sS L ci' -ro Il -- --- (� it 24- 10 ?o `�eo io 10.3' P'lEDty SAND , 111-5,1,4111-5,1,4-�.___. de.tis,e -VT NC . SI\\- , \YE�e. clay_ .._- - W ei-. LOCATION SKETCH • • GRANULAR: COHESIVE: _ .-)1.0,,,,,\ 0-10 Loose 0-4 sat 0-307. Trace F SV Wh �/ VQ e 10-30 Med Dense Dense 4-8 Med Stiff 10-207: Little / w�V.el >50 Very Dense a-15 15-30 Stiff Very Stiff 20-357. 35-5030-50 7: Some And I LOG STATUS: PRELIMINARY FINAL: jl EnviroGrot.ip t_imited Cr_nr..nni , Colorcido CLIENT LeAtt)q 2, Noiit, America BOREHOLE LOG PROJECT LOCATIOI CO PROJECT NO _ L E- O 5 3 BH NO. PAGE 2 - NORTH DRILLER ✓1MLLINg EN)t)NEGRS INC. DATE START 4/19 /2OOi DATE FINISH 4.A q /2.00 EAST G RD ELEV. T0C ELEV. RIG C NNE 45 BITS 8 2S H .S. A.1 FLUIDS '--- LOGGED BY Chc r©ev S.. SAMPLE TYPES: Cuttings WS Wash SS)Split Spoon NX NX Core Dry Core CS Continuous Sampler Other: DEPTH (FT) C - 75k SAMP NO. TOTAL DEPTH k e WATER DEPTH 1 / SAMPLER SPECIFICATIONS: Length Z .5 O.D. 5 i. D. Material -1-Q-'1 Liner '-- Other SAMP RECOV. BLOWS SYM SURFACE CONDITION: C -I' i'Ct-SS TYPE FT/FT per 6" SOIL/ROCK DESCRIPTION SOIL VAPOR rinD flog HS Core (0 =t3 =15 16 =18 19 - 2 2-0 ZZ t O ,-3/ -VD \\ . o' Nth evE.C.b\rE Rai Averec) ‘‘.0 -10 14.c5' -- C tk t v e -- 61 -PT . G'Y sow sc �c� trace_ 5, l} SS3 14'10747 11- 2-0 25 29 30 14.PJ% t5.T' CLAISToNE . 61.7 `vtxt, ±ia t!2 Salr,c .`'Yaea- Sl t ty •�/ec1 YFU+ve.Y� moil . L -N7) OF oR� NoL F N[a bV w)RE ON n [C NJ W EL . INST.41L411 c11) 2 4 PV C. $ -f00c vC re.Evt Cc a —a .6- Loa_ �-4-P R1 SSR —3 40 i ' Cov.CY .>z. cc reed 509-' to r3;9-/ Be vik„ It_ z' s' CaDao 13.E��lal4o' �;1�eAc towd 3 - (7r LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER 50 F S°why u',�' Aq l GRANULAR: e—IO Loose 10-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 Med SLIM 8-15 SUM 15-30 Very Stiff 0-10% Trace 10-20%G Mlle 20-35% Some/ 35-50% And LOG STATUS. PRELIMINARY: FINAL: til l=r•1virOCti1^oup 1_�,-i„t:t�t:i Cent C .foracit. CLIENT .e America, BOREHOLE LOG PROJECT LACATIO Sor, CO n 1` 'PROJECT No. LF -O53$ Avid, 4 X_14.0 NORTH DRILLER KIL14Na ENIkNIFieS INC. BH NO. PAGE OF DATE START 4 /19 /2051 - DATE FINISH 4/1C /:s7 TOTAL DEPTH WS .3' EAST CIII) ELEV TOC ELEV. RIG CME- t5 BITS Se2S }.H •' -A.I FLUIDS LOGGED BY CharoeV WATER DEPTH SAMPLE TYPES: C Cuttings WS Wash 610 Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: , SAMPLER SPECIFICATIONS: Length Z -5 0.D. Z" I.D. ...La_" Material Stec( Liner - Other - DEPTH (F•) BIT CASING DAMP NO. SAMP RECOV. TYPE FT/FT BLOWS SYM SURFACE CONDITION: GrA SS per 6" SOIL/ROCK DESCRIPTION SOIL VAPOR PlD o FID ❑ S Core i-4 =s =G =1 =g 4?s 1. D. AvrY0, Rio 4' -to 4.0/ Cu% AND CLAY .D b . sew, rooks ,_ sS 1 4' to b' X6' SS -- 24'4 SS 2y �`Ty Z 4,d -to �J . b CLA'i DctAk 6,a,, , , 1011(a s11 -1- s SAND AND Nth \ITL, 12- 3,�t hrnD.ci, dQ�%Q- 'raClL si��' Mc.); S.-1 to 6.o' NO p,1cov E R`f Uo1eFecl c �' 6,gio R,o' "SANi≥ /KID GRAvsL Brbvwt Sore Aio? / U to e� i a wl e� eft S ossnQ.0-104, , Ve Yy rnvi5+ SS 2. `oil q_cf�o,o.o' SAND AND GRAVFL . LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER SQL CJ T I OM GRANULAR: 0-10 Loose 10-30 Med Dense COHESIVE: 0-4 Soft 4-8 Med Stiff 0-105 10-20X Trace Little n F' Sl�V1Y�tif 30-50 .0 Dense Very Dense 8-15 15-30 SUff Very Stiff 20-35X 35-50X Some And \AIWel 4/ I.OG STATUS: l/ PRELIMINARY .................__. __...._._.__..,_.__._._ FINAL Erivirc-,Group t_irnlzNcl Cedrarv,ial. Colorado BOREHOLE LOG CLIENT L.a-fCA.YQJ'E' NotNoftIA FIr1er1CU PROJECT LOCATION 'tiai lSor, CO PROJECT NO 1. F - U 5 .613 PAGE 2- OF NORTH DRILLER ✓1S\L1INg ENC-MEERS INC. DATE START a' /i9 /7o? EAST RIG CM F q'5 DATE FINISH 4 /15 (/2007- CRD ELEv BITS 8.2S K.S. A.I FLUIDS -- TOTAL DEPTH 18.3 TOC ELEV. LOGGED BY Chor©etn S. WATER DEPTH 1 SAMPLE TYPES: eCuttings WS Wash Split Spoon NX NX Core Dry Core CS Continuous Sampler Other:. SAMPLER SPECIFICATIONS: Length Z -s Material Sie'e' 0.D 2.4'Liner I. D. l --3" Other 1 DEPTH (FT.) BIT CASING DAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6' .J. SURFACE CONDITION: C--;r•I^a- SS SOIL VAPOR PIOQ FTD❑ BC RSlCore SOIL/RIXCK-. DESCRIPTION - to .1'711 = 1 2 1.5 P4 r-15 `i6 - -`1 = lq. •- - 8.2t, l-i.S,A, Z' 4. 5 t2,.3 --- r 4 up tv 2-1,Icln diawl eier- 'fiat.2 ctam/ w �"k , 10.0 *o 11,0"..N O g,C.©v5.1Z`f Au eye() -to 14' ti.o'to 14.0/ - Cv't'thcl -- cAND AND I f1AVEI BYnvnn , S0,141_ 8 up t, 2. - I v,c.1, n oS) ede*.. W -et - _ ..... SS 3 VI- - o i6' .. SS N 24 5 10 is 14.0% 15.5' S ANI b AND tf(AVEL , "grow, )(ma.dean°Qsto,e,s v �b �--some_ 2- -- t teiClA c41-o..�^Q is . lA..)P 1S.5'--ott.o N0 RE CO VEfV- Q . Q req_ 14-1 16.o/ -f -o ti.o - Cott.-tiQ-,y.g SAND AND 1.� v 10 1O 3 4 5n/-1 .-. g RA v - - e 31-6 A,. , s w4.,Q.. CSC love-- v 0 s 4 1'3' *o rt.' o Yo,•-,e� - - 1 01-F0 lS .3' 6.44-`c STONE . .1(4.y vn F lG F N 17 o f BoRt(ji5 - - Sit iy W as Lyej Y►'t o t $C . ! -- END of oR,WY.: - LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER S Q q_ 'pI .— GRANULAR: 0-10 loose 10-30 Ned Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Solt 4-8 lied Stiff ii -15 Stiff 15-30 Very Stiff 0-10n Trace 10-20% little 20-35n Some 35-50n And 5 ' SU yin/ ` _' If �/v iV�a\/ r B S L0C STATUS: PRELIMINARY FINAL El EriviroGr•oup Limited GonLann�il, Lolrn-erxi CLIENT Latch Q %VOrT F{YY�Q,-tiCG. PROJECT LOCATION -05 J �h Sow, CO PROJECT NO. F a NORTH EAS1' GRD ELEV. TOT ELEV. BOREHOLE LOG BH NO. PAGE ,.. OF 3 .__......_ DRILLER .PrtLLiNC ENC,INEcRs INC, RIG CAE 75 BITSg.25N ,2V`11.S. PI.1 FLUIDS - LOGGED BY Chckroev, S DATE START 4/9 7 DATE FINISH 4/(9 hero? TOTAL DEPTH 1 e0 3 WATER DEPTH '9 ' SAMPLE TYPES: Cuttings WS Wash �J Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS: Length 2 O. D. 2 I. D. I . Material SfeR' 1 Liner — Other — -. DEPTH (FT ) BIT SAMP CASING NO. SAMP TYPE RECO V. FT/FT BLOWS per 6" SYM SURFACE CONDITION: IraSS SOIL/ROCK DESCRIPTION SOIL VAPOR MO .O HS Core S?s H.S,A 4.25 z ' INC 10 --(oot TLCYAp..ov1 M w J covi l,A) 00,8 ! o e k cap -- Riser — 3 -t0 4.1 t anrg, cn-- d fie 2( 2 �rQ 6 3' `� O 16.3 BRu uo 1u C f) 2-f o5' Cap 131-t.0 IC .S' F, l-1-er somii 5' +1) )9,17 3 LOCATION SKETCH DENSITY: GRANULAR: 0-10 Looso 10-30 Med Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-e Aced Stiff 8-15 Stiff 15-30 Very Stiff PROPORTIONS: 0-10X 'race 10-207 Little 20-357. Some 35-507, And REMARKS/WEATFIER so F ,9uyul v‘ fd/ LOG STATUS PRELIMINARY. FINAL. ✓ +I' EnviroGroup Limited 1 Cermannlel, COiOrPJuo La tc�r fLCLIENT2. kkith Amer cck. .._ PROJECT LOCATIO 'J in d SOY , CO PROJECT NO. L F- 0 53g BOREHOLE LOG Aid, .l�ari OH NO. q PA(.F. 11F NORTH DRILLER{ 1LLINg ENIQINECRS INC.. DATE START 4/zoizoo7 EAST RIG C l • Mi E ".35 DATE FINISH 4/zo/zob9- GOD ELEV BITS 2.2S'H.S.•A•IFLUIDS TOTAL DEPTH 161 TOC ELEV. LOGGED BY Charoel, S. WATER DEPTH q' SAMPLE TYPES: CCuttings WS Wash Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: SAMPLER SPECJFICATIONS: Length Z • 5 Material StPO. 0.D. 2''_� Liner - 1.O. ___.-_ ....2__.___ ___.... Other .- ____._..___....... DEPTH (IT.) BIT CASING SAMP NO. SAMP TYPE RECOV. FT/FT BLOWS per 6" S.,,M SURFACE CONDITION: (�roCSS soQnfloa P1° SOIL/ROCK DESCRIPTION BG HS Core t -2 c -4 5 _ =- G 4 t. 2 i-9 I. to g 2S Hs.a• G ze .0. • A u5 lzr "-o 4 0 10 4,o' - CGiti SILT AND t CLAY- l�ar1c, kin -ow, , 1Ya ci- $ow,a , moie ZS 4'�fo 6' 3 S s ie ___. 2`� 4 3 ; ____, -.... 4.0' to 5.3' SAND AN l7 -TRAVEL, -�•- -- Brow, toed clev4S.e tra.c.s� 3 H _ - ra,C.e. dal . s l o f 5.3' t0 6.o' No R,ECo v E R`( A uger ed i O q' 6.0'to'1.0' ... CU's-tt N)i) 3 SAND A a S RAV EL . -8,-To,. :tic,. si t.k , � -tra.t& c.kc,t Mois S S 2. 61 k O tt' ---- GO 1-2-"10 24 15 Q.o'j© io,o/ SAND AND QRAVEL, BTOWv1 ev1St_ so1^'lA cxv-• t t jCl 2- —I hci+ Aio. m.i,g r ' trace x,11 - Wei - .-- LOCATION LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER c� U A c4/'a� l GRANULAR: 0-10 loose 10-30 Mad Denee 30-60 Dame >50 Very Dense COHESIVE: 0-4 Soft 4—e tied Stiff 8-15 Stiff 15-30 Very Stiff 0-10% 'hate 10-20% Uttle 20-35% Some 35-50% And 5O F SL -3,1)A7 (/ LOG STATUS PRELIMINARY. FINAL l=nvirsoGroup Limited Contonnitil, cencipinae) L_ufcAY e.1rt,k n America. BOREHOLE LOG CLIENT ...._....___•--_- - - t PROJECT LOCATIO - W �''+d SnY C O PROJECT NO. LF-O53$ NH NO. PAGE 2- OF 3 NORTH DRILLER .rfNILI.tN� E(\lC3INECRS 4NC. DATE START MO «•e? DATE FINISH 4-/2.0/2.01,7 TOTAL DEPTH 16' EAST RIG CNE E 5 BITSg.25 1-1.S. Al FLUIDS �-- LOGGED BY Char©ev S. GRD ELEV. ' TOC ELEV WATER DEPTH l/ SAMPLE TYPES: e Cuttings WS Wash I S Split Spoon NX NX Core Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS: Length x• y O.D. Z 1.D. 1.P•. Material -1-'2-e'l Liner Other } DEPTH BIT ! PT 1 ,CASING SAMP NO SAMP TYPE RECOV. BLOWS SYM FT/FT per 6" SURFACE CONDITION: Gq-a-ss SOIL/ROCK DESCRIPTION SOIL VAPOR PIDO flD❑ fiC s Corc -40 X11 --13 --14 =15 -1$ =19 20 $2 4r 2 1._D. 14 10 to-0� NO REcoQ ER1 A 4?.YP-cl -to 14! e - C o' - q.AP1 AND QRAV E.L - %Yowv\ s o PQ SkovtoS t)9 to Z- ;,c\ ckla neker SS 3 144' `J lS� 12 12 24' 19 Z0 ^N i� O7- 'GORE )O F 14.o`t5 15.5' S(LT5TONE. 6'ly s t . No' fi''crack s cad ,�YOt.C ¢.. c L,.y we.Att,Yea vQCy Wlo} _ p1ugeTed o ti6' •F.N OF30REE-10LE rnoamtv,q �� iwElaacrflo t z 4 PVC. to- at -it S c Ye.lv1 (vVN -9 LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER GRANULAR: COHESIVE: 0-10 10-30 loose Med Dona. 0-4 4-8 Soft N.(1 Stiff 0-107. 10-207. Trace Little 50 V St -,A7 30-50 Dense 8-15 Stiff 20-3531 Some >50 Very Dense 15-30 Very Stiff 35-50% And LOG STATUS PRELIMINARY. •_ FINAL: Erivir•o.r.OUP LirrtiLr.d Con uonnlal, CglgrHfJcl _t'O` TG r N triT Fi m e ri cc5, PROJECT LOCATl0 w 1,8 Sop CO PROJECT NO. L F- O S 3$ BOREHOLE LOG BH NO. PAGE OF NORTH I, AST C RD ELEV. TOC ELEV DRILLER TikILLINa ENGPIEERS INC, RIG C_ VE 75 BITS' .2S' H •S. q. I FLUIDS - LOGGED BY Cho5rOetn S_ DATE START 4/WOy(z1903 DATE FINISH 4120 TOTAL DEPTH I6 WATER DEPTH !1 SAMPLE TYPES: Cuttings WS Wash S Split Spoon NX NX Core SC Dry Core CS Continuous Sampler Other SAMPLER SPECIFICATIONS: Length 2 �� O.D. 2 1.5. f.7° Material St)e'd Liner Other — `s DEPTH (PT•) BIT CRSING SAMP NO. SAMP TYPE RECO V. FT/FT BLOWS per 6" SYM SURFACE CONDITION: 4. -.S'S SOIL VAPOR PID O F D (] SOIL/ROCK DESCRIPTION DC Os Core E 4.2s. t). CwSowy 6 LOC.k- 4 Ser -3 a 5,3" Co1.ncreto o -foe _ SCYQ.Q.vt t:1' t D 1S.�'J €rllbvt:t cto P 2.''�' O 5 s Ca.? 1 5.3 -i'o 16/ Fact So►oJ 5 to tAn c._:.OhcY/ tO 1 boo '3C d 4 b0.oS Bt4 otovi ij e. c14-", 'z bet. S LOCATION SKETCH • GRANULAR: .• V, COHESIVE: ,v�.a. nr.m�+nra�WEATMat 0-10 Loose 0-4 Soft 0-10X Trace F St.}s. ` 10-30 Med Denee 4—a Med Stiff 10-200 Little / U Q_ `A 30-50 Dense 8-15 Stiff 20-350 Some >50 Very Dense 15-30 Very Stiff 35-50X And '..SC STATUS PRELIMINARY. FINAL: V EnviroGroup Limiter, Centennial. Colorado .4 CLIENT. Lafoo e Noitt, America PROJECT LOCATION W iR Sod', C0 PROJECT NO. Lf - 0 5 3 $ NORTH EAST O RD ELEV. TOC ELEV. BOREHOLE LOG Aid., 4 4 d6,4 DRILLER MILINEt\i1NE1 RS INC. RIG CME-"3-5 BITS R.2S H•S••A•I FLUIDS LOGGED BY Channel" BH NO. PAGE OF 2 - DATE START 4/20 /260 DATE FINISH 41ZO/Ztx%o7' TOTAL DEPTH 15.3 WATER DEPTH 4/ SAMPLE TYPES C" Cuttings Split Spoon DC Dry Core Other: WS Wash NX NX Core CS Continuous Sampler SAMPLER SPECIFICATIONS: Length Z • .5 0.0 z- ,. 1.D. 1.7 Material ste.2.1 Liner Other . -- DEPTH (FT.) BIT CASING DAMP NO. SAMP TYPE RECOV. FT/FT BLOWS, S per 6� URFACE CONDITION: Grex SS SOIL VAPOR PID❑ PIO0 SOIL/ROCK DESCRIPTION HS Core =3 =4 5 =6 =rj to g 2S 0.S.1 0 iJ 7:D. _3eTecl ` I, 4' o -tee 4.4 CLA`f . 170.r�- tyoc2 YmofS . m© -‘S ss t 4 / 1 , ' 4.0 -i-o 5.3' SAND AND GP,AVE 41 3 3 Brow,, ©ovQ, Sovha. ` -lovv2 ; ue 10 ?_-- ch,y,et -, "Aye, \>A e_t - - 5.3'to 6.0' N O f ECuV C. R'f Auce,p a r 6.0%9-0 - CLItt l rio) - GctA\IfL . 5Y(;vl.vt sow12 sties - SANIi AND up Jo Z - 1Yutn clza-YMP-XRY f`trtLc 2 . ss 1 q' k‘' .o' +o )0.5' SAND AND iSZAVEL. Brow, , l ocsa ; scym.e. ulO i s up to - w44 LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER GRANULAR: 0-10 Loose COHESIVE: 0-4 Soft 0-109. Tract �� s..`' ,,,N f0-30 Med Dense 30-50 4-8 Med Stiff 8-15 10-201L Little Dense >80 Very Dense Stiff 15-30 Very Stiff 20-359. 35-50. Some And 3UVW1 1.05 ST ATUS: PRELIMINARY: FINAL: _ EnviroGroup Limit ed �I Centannlal. Colorado CLIENT L cfo 9 . Nof is America. PROJECT LOCATION Wih Sol", CO PROJECT NO. LF-053 BOREHOLE LOG BH NO. ID __ . PAGE Z OF_? __. NO RTIl EAST En 1)1EV 'roc ELEV. DRILLERD1LL1N4 ENC-><iNEERS INC,. RIG CNE -5 BITS$•2S/,I"1.S. A.IFLUIDS y - LOGGED BY ChArOet, S. DATE START 412.0freiR DATE FINISH 412.C12.907 TOTAL DEPTH 153 WATER DEPTH SAMPLE TYPES: Cuttings S Split Spoon Dry Core Other: _ WS Wash NX NX Core CS Continuous Sampler SAMPLER SPECIFICATIONS: Length z .5 O.D. 7" I.D. I -3"" Material Liner Other DEPTH. SIT DAMP ( FT• ) CASING N0. DAMP RECOV. TYPE FT/FT BLOWS SYM per 6' SURFACE CONDITION: a. PQ. SS SOIL/ROCK DESCRIPTION SOIL VAPOR PLOD FIDD BC HS Core —1 fr -13 8.21; t�s sA �f 4 4 2s' 1v -15 1531 =18 3 15 10.5''011.o MO k�Gokl.e.1 ( 16" 16� .FWD OF S4 4 acy 9u'4, to zo s0'l41 ja,s 1 1.929 bA A c,cjareel to t4' il.o'to t4„0' - cukh0, - C;AN1+J AND C-3RAV TArevq,, ve s s{ t t kmQ SS14''1-0W 140 `�0 153' SILTSToNE. 4Tey Veyl hi -_k c.10,/_, t; tQ SOA,.d s'141,41y weof1-el. \Pt,/ mops€ ND OF 3oRELbL t' ort.;{oript e^/at( Lvt,facittrsvl 7-I PVC 40 -roof screevt MW -to casiv.3 s4 Loci 11 SR& —3 to 3."3'' 6.ACre.t L ct -C) L5 screw 3:3 -/-to 13,x' Be4o u 1e d,,ze 1.5#to 3i Cap 139'+0 14/ R ltey sow 3/ {o 15 i e 3 LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER I I (SQ k_ P 4 o,v1 GRANULAR: 0-10 Loose 10-30 fled Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-0 Med Stiff 8-15 Stiff 15-30 Very Stiff 0-10% Trace 10-20% Little 20-35% Some 35--50% And W F a JUh7 .LOG STATUS PRELIMINARY: _ FINAL Ei 'li mGr•oup Limited Cont®nntel, Cotorsoo CLIENT t.CIfC`Y .e. NaYt1i Ame1kcs. BOREHOLE LOG PROJECT LOCATION W;Y ciSoY, CO PROJECT NO.-. l,F-0538 ,LJv,d‘ 4 RIC11.,4 NORTH DRILLER .IJrVLLINg ENC- \NEERS INC. BH NO. I PAGE I OF__ -3 _ �._.- DATE START 4 /7-0/2oo DATE FINISH 4-12.0 /2.DC EAST RIG CME--�5 BITS '.�S N H • �•• � .' FLUIDS LOGGED BY Chor©evs S. CRI) EI_EV. TOC ELEV. TOTAL DEPTH 1-3-03 WATER DEPTH (3 ISAMPLE TYPES: C Cuttings WS Wash +c$ Split Spoon NX NX Core DC Dry Core `--CS Continuous Sampler Other SAMPLER SPECIFICATIONS: Length Z ;,5 0.0 ._ . x 1. D. 1.1 Material Steal Liner --- Other . - DEPTH (FT.) BIT DAMP CASING NO. DAMP RECOV. TYPE FT/FT BLOWS, S per YM 6' SURFACE CONDITION: Grp SS SOIL VAPOR Plop PloD SOIL/ROCK DESCRIPTION HS Core 2 3 4 G -10 g 2S I-S,A . to 4•-' o 4,0' 1L7 A of aLA`{ boovvv, 1i{'11io sown1 SS 4/ to 6' 12 2-4 12 20 4.O'to 5.S' SANI) AND aRA\IEL. . -Brow" wi.e cd , Somme SIovi.AS vp 'to z-iv�cln dic�vKe �IYotC� tlt. {•o 6.o' No REc.IDv .P..`f Av3exed to o' C.O't0 t 0'-tu'*ivIq - SAND AND t 1RA\M-L _ '8Yovitn S O` r2 0-10,Q0 = - up 1. Z.-ivtc.{/1 CJIa'Me.leY,+-rac _ 1 z4" 9 c8S 2 9 / fo 9'-}'o 10,5 `SANt7 AND GMVEL.-zo 1 -mva de,e ) GOm2. TAOY,.Q S op ID LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER ---777 f)' �` Jv \� 1 J SSoft n C. �� GRANULAR: 0-10 Loose 10-30 Med Dense 30-50 Dense COHESIVE: 0-4 4-0 tied Stiff 5-15 Stiff 0-107. ]0-201C 20-35% Orson LitUe Some .0 Very Dense 15-30 Very SUff 35-50% And LOG STATUS: PRELIMINARY. FINAL Envirof}rou� L=f° GQ.�te nniaL Colorr�rt CLIENT . Illo lIA America. PROJECT LOCATIO'* WirtSot, CO PROJECT NO. L F- 0 5 3 fNORTH • EAST BOREHOLE LOG BH NO. 1 PAGE 2- OF 3 GRD ELEV LTOC ELEV S'e _ DRILLER ✓r\LL`Ng ENI INEERS INC, RIG CNE fJ BITS S.25'hH.S. A.l FLUIDS - LOGGED BY ChcroeteS. SAMPLE TYPES: Cu WS Wash SS) Split Spoon NX NX Core Dry Core CS Continuous Sampler Other: DEPTH (FT) 6-17-.1r DAMP TYPE RECOV. FT/FT DATE START 4120/2007 DATE FINISH 412.0/2.00 -1 - TOTAL DEPTH 13.3 WATER DEPTH (I/ SAMPLER SPECIFICATIONS: Length Z y5 O.D. Z 1.D. l.7' Material Liner Other BLOWS SYM SURFACE CONDITION: al..- SS per 6' SOIL/ROCK DESCRIPTION SOIL VAPOR PID ❑ OD Core =1z =14 --IS Lib I� 425" 10 13 - iartn dtarf�e}e� races %ilt W szt zoo 1 o 15 241.7 15 1O -16 1U, 5040 AvgQx-ecl to 14-, 1,4 .O' C ;� - �AIv l7 AND GRAVEL_ . ' 1OwH g sowo_. 2. Ohe.s up 10 2.- oc1A d;a�rnQ er j-fiIOtC H _ - SI , V.121 14_01't -c, I SS 3 14' to \a' 5.5' SAND AND gRANSL... 13x o wv, hrte_a de, SQ. t i \ Q A'AohH S UQ to a--encli1 d1•grne..ke�r, e_ s51� . W.A. 20 F"t�l l7 0V IS.s'� tS .�f Stul ST©tya . 0,9 St S f' 1 kittte. Sowtri olodaYotet' B it LE- 1S3fto 16.0f NO RECOVER`( _.._ A kl erect SS A- I6' ka t 8' 16.o'�o 1i.3' SILTSIoNF . Gcovi Vef s-hc'Q, sovvvd , Yr, oc:LTA- I w COtkLEY ec) . vex- y w'bist —1 LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER ''OF. S Uln y I f) .....0 Q ) \�� GRANULAR: 0-10 Loose 10-30 Ned Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 Med Stiff 8-15 Stiff 15-30 Very Stiff 0-10X. Trace 10-20X Little 20-35X. Some 35-50X. And LOG STATUS PRELIMINARY: _ FINAL: EriviraGroup Limit eel Genconni®[, C01tlrBCq CLIENT 1 G'MAr z Ne.TAIA NTrnefica PROJECT LOCATION 1J Ord So CO PROJECT NO. (. F - 0 5 3 BOREHOLE LOG BH NO. PAGE 3 11 OF 3 NORTH DRILLER ✓T.11.1.tNA EN�(NEERS INC. DATE START 4 /zo' %oc DATE FINISH 4• /zO/2Ooj TOTAL DEPTH 17.3 / WATER DEPTH 9 I:; AST RIG CMS. 75 BITSgs2Jy(1-S.A.lFLUIDS `" LOGGED BY Charel S . CRD ELEV TOC ELEV. SAMPLE TYPES: CT Cuttings WS Wash SS Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other _. SAMPLER SPECIFICATIONS: Length 2 ., 0. I.D.f " Material Ste 'P_ Liner Other -- DEPTH (FT) SIT CASING DAMP NO. DAMP TYPE RECOV. FT/FT BLOWS per 8" S SURFACE CONDITION: ►'ASS SOIL VAPOR PIDQ TIDO SOIL/ROCK DESCRIPTION as Core 8.2s NSA. EN -0 oF 1oRE \0L_�. m0,1 oY 1,"\ \,1 e.W LI sta i1C\k•blT__ 25 ?NC I0-fock Scusm &l .p ��Quev Ar Loci "3 to S�1 C.otncreia- o'�oZ - Sc.TeQ.,A 5 'trots j-/ vi,1,ctA,P z o� exp. 5 1(' F;tiox S° 0J 5 to Ca��Ye e � ?e.,,Ac ri:1Q. c Irv, ' 2 bo s Miler SC� 4 190.°�S a J LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER Sa. Q 'PI0-10 GRANULAR: Loose 10-30 Med Donee 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-A Mod Stiff 8-15 Stiff 15-30 Very Stiff 0-10S Trace 10-20S Little 20-35X Some 35-507. And -to F 3tY\W\f (/ LOC STATUS. PRELIMINARY FINAL Ial EnviroGroup t_imiracf r Cenuenniai. Colorer. CLIENT Le fo'r .. t'030 L America, BOREHOLE LOG PROJECT LOCATIO�et^)in Solr, CO PROJECT NO. LF -O 53 Avdt1 �- Ric1,1ciT BH NO. 12 PAGE OF 2 - NORTH IL1INg Ect1NE RS INC. DRILLER /i,!N DATE START 4/Zo/Zoo7 EAST M RIG C i • I E --i-5 DATE FINISH 4/20/Z007' GRD ELEV. BITS 9.2S"H • C.. 4.1 FLUIDS TOTAL DEPTH I4.3' TOC ELEV. LOGGED BY Char©evs S. WATER DEPTH 9, SAMPLE TYPES- a( Cuttings WS Wash Split Spoon NX NX Core DC Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS: Length Z • 5 Material StQQ1 . __� ._ O.D. -a. Liner ,, _._..__=.. I.D. I.N Other - - • DEPTH (FT.) BIT CASING SAMP NO. DAMP TYPE RECOV. FT/FT BLOWS per 6" SYM SURFACE CONDITION: Cr'''. E.G SOIL VAPOR MO F1D❑ SOIL/ROCK DESCRIPTION 8G HS Core _ �2 ^4 E S G E C - i- tr $.2-S a?s4 I.D. A u3erec (o 4-' 0 Ct 4.0' - c ui-i h -- SI L► A MD e -L/ `(, ?).Ypwh , TY'GS.(.O. 845,a ;trace..YL90S_ 0)p`SL- --1- - S%,1 4' -to 6' ---I-H---- 18(' _ 2�j- I 2 2 4.0r to 5.5 FINE SAND . By,,,,o red bwv. ( oost. ISo'm e. sr1.}- , � I;1� YaVeA Mops 55,` 'to 6.o` No RECAvE-≥ A u3..reci to 9' 6,o'to9.o' -- Ct.4 ns.3 - EtNE sAND. Drowlr, -Icy tree b•-oa s. , som e S,lV J } 3 9.-S2_ c -t' --o kk 1 . Gb' 24-" 2 9.o/*0 10 ' MEDIuM sgr.D . 1 Tc = 'Ae.d. devEse. Sorn, S,1 -}1 -,q\ - (3,,,,,A, W Q..t . LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER C' r� e v` GRANULAR: 0-10 Loose 10-30 mad Dense 30-50 Dense >50 Very Dense COHESIVE: 0-4 Soft 4-8 And Stiff 8-15 Stiff 15-30 Very Stitt 0-1071 Trace 10-207. Little 20-35X Some 35-5071 And L i0 ` S"V 7 l/ LOG STATUS: PRELIMINARY: FINAL enviroGroup Limited Contenniol. Color -moo c.:.IEN; [stab R. No to America. PROJECT LOCATI�wNh°Sore Co PROJECT NO. LF-O53e NORTH DRILLER TikILLINg ENGINE RS INC. DATE START 4�O/2007 EAST RIG C ME 45 DATE FINISH 4/2A/20. q LC,RD ELEV BITS $•2°1 H.S. A.I FLUIDS '-- - TOTAL DEPTH /4.3 ' TOC ELEV. LOGGED BY O10,r° et,, S. WATER DEPTH q' SAMPLE TYPES: e4,iittingc,c. WWash NXNXore Dry Core CS Continuous Sampler Other: SAMPLER SPECIFICATIONS: Length 2 -5- MaterialtQ e.l 0.D. 2-'y Liner J.D. 1-.3' �- Other _ !DEPTH. (P1' ) NIT CASING DAMP NO. DAMP TYPE RECOV FT/FT BLOWS per 6' SYM SURFACE CONDITION: C-�•ra.SS SOIL VAPOR AID❑ F SOIL/ROCK DESCRIPTION a;, Hs Core . - -I0 ^11 ,_ 12 13 • 4 82 ti.sA •2s' I `2 16 10.-51-1-0 tt . o' k)C) P E eb'J E.R1' At. eyed lc) t3' _ 1►.0'-10 (3.W ..ueottiti . -,MEDIUM SAND BYo o sowle 510- i,%.R.- ob ✓el. 'w.. -r G 3 (3' -to t5' 8S 10 z.7A I3.o'to (4.3' SIt_�SToNE , C1re\. _ V eY St 1 l i t.e sar°d 1; *g. • cm, s ()w.. noct.¢.T4ely .._ c6 Il 12, 1cl L..;C5ekv\ ?o ip. 3 c J o „ t^ - A &u. - ID o bc, J .. t b 130RE •�S g 0 wCkk\,11x . NeYy . McASk".. AvneYeel io VA- s' E NS QF BoR,EtioL- MntitT0P..( G WELL IN°TALLA-T ■�- - 2 y PVC.., ca —6,A &CYDg,vO nlw 12- Ccks1,0-• L08, - ca Ri sex --3 0.3 3 Cov cret L a to n\L G S.31 -10t3, -ii tse,-10,A, k, z • _. Ca. 13:1' 14' F(kOY 3ov,rl 3'to lq 3 - LOCATION SKETCH DENSITY: PROPORTIONS: REMARKS/WEATHER 00-10 /�, V Q"� �� GRANULAR: Loose 10-30 Med Dense 30-50 Dense >50 Vary Dense COHESIVE: 0—A Sort 4-8 Med Stiff 8-15 Stiff 15-30 Very SW 0 -ton Trace 10-207 Little 20-357 Some 35-507. And -'J,') F JUvw �ri(_J l`// BOREHOLE LOG BH NO. PAGE ._ Z OF -2— LOG STATUS: PRELIMINARY _ FINAL: _ V EriviroGroup Limirad APOENDIX ER LEVEL ELEVATION. TIME SERIES,GRAPHS (HYDROGLRAPH'S)a PARSONS MINE M0NITjORING-WELLS Water elevation (ft asl) 4755 4750 4745 4740 4735 4730 4725 4720 4715 4710 4705 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 ---l-Water Level Bedrock Elevation Ground Elevation Date Land surface elevation = 4732.548 ft asl Note: Elevations are from survey data taken in December 2022 TITLE: Water Level Elevation at Parson Monitoring Well MW -1 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado eaalaInlik h TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT U 117-8741006 FIGURE G-1 DATE 08/01/2022 4755 4750 4745 4740 ^ 4735 4f 0 4730 :7; r6 a) v 4725 Sv 4-) its 4720 4715 4710 4705 -r- --, • • • • a..... - - n i • • Nim•ip-"- e•Ariv\,,gits. ?Ph% • 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date —4—Water Level Bedrock Elevation Ground Elevation Land surface elevation = 4739.56 ft asl Note: Elevations are from survey data taken in December 2022 TITLE: Windsor East Water Level Elevation at Parson Monitoring Well MW -2 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado FOISMINIMMIN TETRA TECH APPROVED DRAFTED PROJECT # CG KG, DS 117-8741006 FIGURE G-2 I DATE 08/01/2022 J 4755 4750 4745 4740 4735 ro 0 4730 ro a) a 4725 S -- a) 4J ra 4720 4715 4710 4705 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date h1/4 tbe% Ares 1 1 t i I # —*'—Water Level Bedrock Elevation Ground Elevation Land surface elevation = 4743.246 ft asl Note: Elevations are from survey data taken in December 2022 TITLE: Water Level Elevation at Parson Monitoring Well MW -3 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado AMINSIMINIaas TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT # 117-8741006 FIGURE G-3 I DATE 08/01/2022 I 4755 4750 4745 4740 4735 co 4-a 9- C O 44 ro 0 4725 C) 4J ra 4730 4720 4715 4710 4705 End of data \W„, .s\ret\ ,Aritb 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date —41—Water Level Bedrock Elevation Land surface elevation = 4731 ft asl Note: Elevations are referenced to the surface elevation provided by Martin Marietta, which is believed to be estimated from local topographic map contours. This well has since been destroyed. Windsor East II TLC: Water Level Elevation at Parson Monitoring Well MW -4 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado eases APPROVED CG DRAFTED KG, DS TETRA TECH PROJECT # 117-8741006 FIGURE G-4 S _ J DATE 08/01/2022 J 4755 4750 4745 4740 4735 a) 4725 a) (3 4720 4715 4710 4705 \r•-•%•-•-\._: r3/4* -%1\ 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date --O—Water Level —Bedrock Bedrock Elevation Ground Elevation Land surface elevation = 4748.444 ft asl Note: Elevations are from survey data taken in December 2022 TITLE: Water Level Elevation at Parson Monitoring Well MW -5 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado orb TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT # 117-8741006 FIGURE ES I DATE 08/01/2022 4755 4750 4745 4740 4735 CD 4-1 C 4730 C) v 4725 v c>3 r 4720 4715 4710 4705 4700 -- I rn Jr4r4\--limake 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date --41—Water Level Bedrock Elevation Ground Elevation Land surface elevation = 4749.825 ft asl Note: Elevations are from survey data taken in December 2022 1/4 Windsor East TITLE: Water Level Elevation at Parson Monitoring Well MW -6 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado f _ h l TETRA TECH APPROVED DRAFTED PROJECT k DATE CG KG, DS 117-8741006 08/01/2022 FIGURE G-6 W Locations 1755 4750 4745 4740 4735 0 4730 ra a) v 4725 L cu 4J 4720 4715 4710 4705 4700 SO• S S • 416V, ,•!lo 471.%) p 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date ---•—Water Level Bedrock Elevation Ground Elevation Land surface elevation = 4724.057 ft asl Note: Elevations are from survey data taken in December 2022 Windsor East 1.1 TITLE_: Water Level Elevation at Parson Monitoring Well MW -7 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT ft 117-874100G FIGURE G-7 I DATE 08/01/2022 I 4755 4750 4745 4740 4735 CO 4f 4730 C) a 4725 a} 4720 4715 4710 4705 4700 End of data i tee i _ 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date —111—Water Level Bedrock Elevation Land surface elevation = 4721 ft asl Note: Elevations are referenced to the surface elevation provided by Martin Marietta, which is believed to be estimated from local topographic map contours. This well has since been destroyed. TITLE: Water Level Elevation at Parson Monitoring Well MW -8 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado ellIIIIIIMMEM1 TETRA TECH APPROVED CG DRAFTED PROJECT Pt KG, DS 117-8741006 FIGURE G-8 DATE 08/01/2022 J 4755 4750 4745 4740 4735 r0 C O cu 4725 4J 4720 4730 4715 4710 4705 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date -- Water Level -- Bedrock Elevation Ground Elevation Land surface elevation = 4727.005 ft asl Note: Elevations are from survey data taken in December 2022 TITLE: Water Level Elevation at Parson Monitoring Well MW -9 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado ogrt TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT U 117-8741006 FIGURE G-9 DATE 08/01/2022 J 4755 4750 4745 4740 4735 0 4730 ro cu cu 4725 v 4720 4715 4710 4705 $64“-' IIIIIMMMIMMIUMMMOMMIntenten-as • ..l ]2^s'= f.•lS V 4„. 464, diestp% 4,10 a 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date et Water Level - -Bedrock Elevation Ground Elevation Land surface elevation = 4723.11 ft asl Note: Elevations are from survey data taken in December 2022 TITLE Windsor East Water Level Elevation at Parson Monitoring Well MW -10 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado APPROVED DRAFTED TETRA TECH PROJECT# CG KG, DS 117-8741006 FIGURE G-10 I DATE 08/01/2022 r 4755 4750 4745 4740 4735 r 4730 O 0 a) v 4725 a) 4J co 4720 4715 4710 4705 4700 • -: Q i %b. .414linftft". ailleaL• alga et% S Well Locations 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date —Oa Water Level r ------R Bedrock Elevation Ground Elevation Land surface elevation = 4724.581 ft asl Note: Elevations are from survey data taken in December 2022 Windsor East TITLE: Water Level Elevation at Parson Monitoring Well MW -11 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado I TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT # 117-8741006 DATE 08/01/2022 FIGURE 4755 4750 4745 4740 4735 (f, r0 0 4730 CD CU 4725 4720 4715 4710 4705 4700 • .46* 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date —0—Water Level -- ----Bedrock Elevation Ground Elevation Land surface elevation = 4725.579 ft asl Note: Elevations are from survey data taken in December 2022 TITLE: Water Level Elevation at Parson Monitoring Well MW -12 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado TETRA TECH APPROVED CG DRAFTED PROJECT # DATE KG, DS 117-8741006 08/01/2022 FIGURE G-12 J ul 03 4- C O 4J ro aJ a& 4725 a) c 4720 4755 4750 4745 4740 4735 4730 4715 4710 4705 i ..w ..0%••-••••-eassar. ass•-••••••ajbas,..----witivia 4700 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date --�— Water Level Ground Elevation Land surface elevation = 4721.131 ft asl Note: Elevations are from survey data taken in December 2022 TITIF: Water Level Elevation at Parson Monitoring Well MW -13 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado Tt TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT it 117-8741006 FIGURE G-13 I DATE 08/01/2022 r 4755 4750 4745 4740 4735 c/') i-� 4- 4730 ro v 4725 4-0 a) 4720 4715 4710 4705 4700 r awe% lame 7/6/2009 11/18/2010 4/1/2012 8/14/2013 12/27/2014 5/10/2016 9/22/2017 2/4/2019 6/18/2020 10/31/2021 3/15/2023 Date ---41- Water Level Ground Elevation Land surface elevation = 4721.422 ft asl Note: Elevations are from survey data taken in December 2022 TM": L[: Windsor East Water Level Elevation at Parson Monitoring Well MW -14 MARTIN MARIETTA LOCATION: Windsor East Mine, Windsor, Colorado (m) TETRA TECH APPROVED CG DRAFTED KG, DS PROJECT #i 117-8741006 DATE 08/01/2022 FIGURE G-14 APPENDIX G-3 SAMPLE COLLECTION PROTOCOLS Windsor East Sand and Gravel Mine; Martin Marietta Materials June 2022 ATTACHMENT G-3: GROUNDWATER MONITORING AND SAMPLE COLLECTION PROCEDURES 1.1 SCOPE AND APPLICATION The purpose of this Standard Operating Procedure (SOP) is to provide guidance for determining the depth to water in a well using an electronic water level indicator. In this SOP, wells are defined as monitoring wells, piezometers, temporary well points, and potable wells. Permanent wells should be surveyed such that wells can be located and water elevations can be determined. At sites where there are multiple wells, a complete round of water level measurements should be collected site -wide prior to commencement of activities that will affect groundwater levels. A permanent survey mark should be placed on the top of the well casing (TOC) as a reference point for groundwater level measurements. If the lip of the riser pipe/well casing is not flat, a notch can be made on the polyvinyl chloride (PVC) riser and used as the reference point. Alternatively, the reference point may be located on the top of the outer protective casing (if present). If using a measurement reference point, it must be documented in a site -specific logbook or on a field data sheet. All field personnel must be informed of the measurement reference point used to ensure the collection of consistent data. 1.2 WATER -LEVEL MONITORING An electronic water -level indicator is used to measure the depth to water in each well. The indicator consists of a wired cable with a probe at the end. When the probe contacts water, the water completes a circuit causing the indicator to emit a sound at the surface. The water -level indicator should be turned on, then lowered until the probe emits a tone indicating contact with water. The distance from the water surface to the TOC should then be recorded using the gradational scale on the cable. The water level measurement should be recorded on a water - level monitoring field form or notebook, then the measurement should be repeated to confirm the reading. All measurements should be recorded to one hundredth (0.01) of a foot. It is important to record the date and time of each measurement along with the well identification and the depth -to -water value since water levels can vary over time. Water level measuring equipment will be cleaned of visible water and particulate matter prior to and after use at each measuring location via wiping/rinsing. The groundwater elevation can then calculated by subtracting the depth -to -water measurement from the surveyed TOC elevation. 1.3 WATER QUALITY SAMPLE COLLECTION The procedure for collecting a water quality sample involves the use of a pump or bailer to remove three well - volumes of water from the well to ensure that the water remaining is representative of aquifer water, then to use the pump or bailer to pass samples of water through a filter to remove suspended particles and collect the filtered sample in a bottle. 1.3.1 Well Purging An adequate purge is normally achieved using this method by removing three well volumes of standing groundwater at relatively high flow rates prior to sampling while recording the pumping rate, discharge volume, water level and routine groundwater parameters over time. Routine groundwater parameters should include temperature, pH, and specific electrical conductance at a minimum, but may additionally include turbidity. It is TETRA TECH Page 114 Windsor East Sand and Gravel Mine; Martin Marietta Materials June 2022 assumed that stabilization of the groundwater measurements indicates the purge water is representative of ambient water from the underlying aquifer. Groundwater quality parameters are generally considered stabilized after three consecutive sets of readings do not vary by more than 10 percent (%), however the criteria for sample collection will be based on purge volume, rather than parameter stability. The time between readings (typically 5 to 10 minutes) should be chosen to ensure enough data have been collected to document the stability of parameters. If the calculated purge volume is large, measurements taken every 15 minutes may be adequate. To calculate the volume of a well, use the following equation: Well Volume (gallons) = rrr2hk where: rr=3.14 r = radius of monitor well (feet) h = height of the water column (feet). (This may be determined by subtracting the: depth to water from the total depth of the well as measured from the same reference point). k = conversion factor, 7.48 gallons per cubic foot (gal/ft3) The volume, in gallons per linear foot, for various standard monitoring well diameters (nominal): Well diameter (inches) 2 3 4 Volume (gal/ft.) 0.1631 0.3670 0.6528 1.3.2 Sample Preservation and Containers Groundwater samples will be collected in bottles which are chosen to be appropriate for the analysis by an analytical laboratory, and may be supplied directly by the laboratory. The analytical method specifies the type of bottle, preservative, holding time and filtering requirements for a groundwater sample. Samples should be collected, when possible, directly from the sampling device into appropriate sample containers, with an appropriate sample identification label. Record all pertinent data in a site -specific logbook and on a laboratory - supplied chain of custody (COC) record. The samples should be placed in a cooler and maintained at less than or equal (≤) to 4 degrees Celsius (C) and protected from sunlight. Ideally, samples should be transported to the analytical laboratory within 24 hours of collection. If large numbers of samples are being collected, shipments may occur on a regular basis after consulting the analytical laboratory. In all circumstances, samples need to be analyzed before the holding time expires. 1.3.3 Sample Collection After purging, groundwater samples may be collected using a bailer or the flow -stream from the pump. Samples collected for dissolved metals analysis require filtration. Groundwater is primarily filtered to exclude silt and other particulates from the samples that would interfere with the laboratory analysis. In -line filters (typically 0.45 -micron) are used specifically for the preparation of groundwater samples for dissolved metals analysis, and for filtering large volumes of turbid groundwater. An in -line filter can be used with a peristaltic pump to transfer the sample from the original sample bottle, through the filter, and into a new sample container. The filter must be replaced between sampling locations. OTETRA TECH Page 214 Windsor East Sand and Gravel Mine; Martin Marietta Materials June 2022 The filters used in groundwater sampling are self-contained and disposable. Disposable filters are preferred and often used to reduce cross -contamination of groundwater samples. Disposable filter chambers are constructed of polypropylene material, with an inert filtering material within the housing. The proper collection of a sample for VOC analysis requires minimal disturbance of the sample to limit volatilization. The following procedures are required to be used: 1. Open the vial, set cap in a clean place, and collect the sample. When collecting duplicate samples; collect both samples at the same time. 2. Fill the vial to almost overflowing. Do not rinse the vial, or let it excessively overflow. It needs to have a convex meniscus on the top of the vial before securing the cap. 3. Check that the cap has not been contaminated and place the cap directly over the top and screw down firmly. Do not over tighten the cap. 4. Invert the vial and tap gently. Observe vial for at least 10 seconds. If an air bubble appears, unscrew the cap and pop the bubble or refill with more sample then re -seal. Do not collect a sample with air trapped in the vial. 5. The holding time for unpreserved samples to be analyzed for VOCs is 7 or 14 days for preserved samples. Samples should be shipped or delivered to the laboratory as fast as practical in order to allow the laboratory time to analyze the samples within the holding time. Ensure that the samples are stored at ≤ 4 degrees C during transport but do not allow them to freeze. 1.3.3.1 Bailer Purging Wells are typically purged using either pumps or bailing. Bailing is a process in which a plastic disposal bottom loading bailer with a string or thin rope attached is lowered by hand into a well, allowed to fill with water, and then retrieved. Once retrieved the water in the bailer is decanted into containers on the ground surface for subsequent disposal. Manual bailing, or the use of dedicated or disposable bottom loading drop bailer approximating 3 feet in length and one liter storage capacity, attached by a string or rope to remove water from a small diameter well for well development and/or sampling is performed as follows: • Open the well protector top, typically removing the protective lock and/or unbolting the cover, to access the well riser piping. • Affix the bailer to the rope, string, or cord with a knotting technique that will ensure its permanent attachment and prevent bailer loss over the course of the purging cycle. Knots can loosen or slip when the rope becomes wet in conjunction with the application of the additional weight of the full bailer. • Place the bailer in the well and lower it to the water table surface, slowly allowing the bailer to sink and fill with water (this avoids turbulent flow of water in the wells casing and minimizes off gassing). • Retrieve the bailer by manually pulling the attached rope by either coiling it hand over hand or allowing it to collect onto the plastic sheeting on the ground until the bailer exits the well riser. Then grasp the bailer and decant the purge water into a bucket or other interim container. This procedure is repeated until the prescribed volume of water has been purged from the well. 1.3.3.2 Mechanical Pump Purging Small diameter electric submersible pumps may be employed for some circumstances. Comparatively high volume pumps, such as a "Whale" or "Keck" model/brand employ a 12v battery or rechargeable power source may be used individually or in series to accommodate deep pumping situations or increase pumping volume. OTETRA TECH Page 314 Windsor East Sand and Gravel Mine; Martin Marietta Materials June 2022 Although this document does not provide a specific description for the use of each type of pump, the application and field use of a small diameter 12v pump such as a "Whale Pump" or equivalent is as follows: • Measure the overall well depth and construct the pump with supply tubing "string" accordingly, allowing extra tubing length as necessary to accommodate discharge to storage and/or sampling containers. The electrical wire supply line should be of adequate gauge and constructed to a length sufficient to access a nearby power source. Multiple "in -line" pumps may be used in accordance with manufacturers suggested recommendations to facilitate an adequate pumping rate and volume in deep wells. • Lower the supply tubing with attached pump(s) in the well to the desired depth, commonly near the well bottom or lower level of the screened interval. The pumping "string" can be affixed to a permanent object, typically the riser protective piping, with a small clamp to keep the pumps from contacting the bottom of the well or maintain a desired or prescribed sampling depth. • Attached the electrical supply wires employing small clamps on the positive (+) and negative (-) battery terminal in the event a standard 12v automobile battery is utilized as power source or insert the plug to the cigarette plug- in if wired accordingly. There will be a short delay until the pumps engage and flow is actuated if wired correctly and the power source is adequate. • As water flows from the supply tubing, place the purged water into an interim storage container, commonly a five -gallon bucket, for transport to a long term storage or staging area pending disposal analysis. The direct discharge of purged water may be warranted based on historical site findings or client direction. • Continue with the pumping/storage/disposal routine until the desired or prescribed volume of water has been removed. lift.locaNERlProjectslLongmont187411117-87410061DocsIDRMS108 - Exhibit G - Water InformationlAppendices1Groundwater Monitoring and Sample Collection Protocols v1.l.docx 111 TETRA TECH Page 414 APPENDIX G-4 USGS WATER RESOURCE INVESTIGATIONS REPORT 02-4267 USGS science for a changing world Analytical and Numerical Simulation of the Steady -State Hydrologic Effects of Mining Aggregate in Hypothetical Sand -and -Gravel and Fractured Crystalline -Rock Aquifers Water -Resources Investigations Report 02-4267 U.S. Departmentof the Interior U.S. Geological Survey Analytical and Numerical Simulation of the Steady -State Hydrologic Effects of Mining Aggregate in Hypothetical Sand -,n -Gravel and Fractured Crystalline -Rock Aquifers By L.R. Arnold, W.H. Langer, and B.S. Paschke U.S. GEOLOGICAL SURVEY Water -Resources Investigations Report 02-4267 Denver, Colorado 2003 U.S. DEPARTMENT OF THE INTERIOR Gale A. Norton, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. For additional information write to: district Chief U.S. Geological Survey Box 25046, Mall Stop 415 Denver Federal Center Denver, CO 802246 Copies of this report can be purchased from: U.S. Geological Survey Information Services Box 25286 Denver Federal Center Denver, CO 80225 CONTENTS Acknowledgments ........:..... �....,.,.,.....,.;...... ,<... ,. ., .., ., .., Fractured Crystalline -Rock Aqul%r . ...,. „•. ., .,,. Gr ml -water Hydraulics and Mathernaatical Method Simulation of the Hydrologic Effects of Mining gate 9 Simulation of Pits in =ad -Goren Aquifers ..:...... ....F;.,: ,.....,. , ....,,< .. 9 Analytical Simulations mai Semsitivitie ............. ....... .... ........ .. ...... . .. ,....s....,...::.,, .,.,,. 10 Simulation 1 -Pit in a medium -size& homogeneous. isotropic aquifer,:... , .... . ..... ............ l Sint, FIGURES Results and comparison to analytical simulation.„.......—.... . .......T . ,,,... , ..,.,.,::., 14 Siniulatinn 2 -Pit in a mediums sized, homogeneous aquifer with tic arose (r ty ..:.. ....... ......... I 3 -Pi r:n a talc. hamtoge ous, isotropic ailuifer,..... T...., . ... ....... ... . ................: ?1 w e wtuife in a medium-sized. homogeneous. Sirmulatic n 4 -Pit it irttulatiott Five issmrapic itquif Simulati€rtt t1-Fi► ve lo d. homogeme Nutoe Kcal Sems tivitlr Analysis , ..:..,, .,.... aim of Quarries mctured G ystalixtie Rock Aquifers , Analytical Simulations and Sensitivities ... .... ....... „ ..,, ,. Numerical Simulations . ., ..,, Simulation 7 --Quarry in a homogeneous. isotropic uifer, Boundary conditions Results and comparison to analytical sitttulutaon.. ..... .. 34 Simulation im a honmo aenemms aquifer with horizontal nrtisatrospy,. .. ,.. 39 Simulation 9 -Quarry in an aquifer with lateral variations of hydraulic conductivity ...... .................* 41 Simulation 10 -Quarry in an aquifer with ground -water flow in deep. low -permeability Slmulatioit l 1 si y ittR zte ii by a hydraulically cup Simula a low-conductivil Numerical Sensitivity Analysis:. ........ •...,.a.. ..:..,.;. ........ ......... ... ....a..., ,o...,... 51 Range area, for t'r cili'an 6. `, l3ra It own relative to distr pit radius. simulated by us+ . One -percent scaled sensiti t alculrated font a pit in a . Certceptual diagram for nu 10. Finite -difference grid and Diagrams of, 11a.,. Numerical simmulation lit medium-si l s nd ad- r l lb. Numerical simulation fit mediu 11 c. Steady-state aquifer of loll l?a. Nauru] 121ry N ward pit in a sand -and -gravel aquifer for thr v imulated by use of the Marinelli and Niccoti analytical solutoon a ewateted pit in a d-ancl-gravel aquifer for three values of Nit:c.uli analytical solution. 12 rnalytical solution of Marinelli and Nic ali+ r interttt cltate conditions aflame for numerical simulation I tdy-state prnining dis! sl aquifer under homage dy-st 16 a hyp onditions . . 16 by a dewatered pit in tt bonsogefrectus. i. atropic sa -an tied by use teat Martuelli as ie, l , ialytical sulutt n ..... ................ . 17 teady-state premining distribution of hydraulic head in a hypothetical reel aquifer under homogeneous and vertically anisotropie conditions.. 20 ad -state drawdawn caused by a desvalmed pit in it hypothetical. el aquifer under homogeneous and vertically aniSottopic'conditions................ ap ittrnerical simulation 3.- "t rdy-state preminiag distribution of hydraulic head in a hypothetical, large sand -mid -gravel aquifer under homogeneous and isotropic conditions 21 Numerical simulation 3 —Steady-state dtnwdown caused by a dewatered pit in a hypothetical, large sand -and -gravel aquifer under homogeneous and isotropic ctrnditions..,:. . rical simulation 4 —Steady-state premining distribution of hydraulic head in a hypothetical. all s td -and -gravel aquifer 'under homogeneous and isotropic conditions ... .............:.. ... . ...:.....,.. 23 14b. Nmnerical simulation teady-state drawdown caused by a dewatered pit in a hypothetical ad -turd -gravel aquifer under homogeneous and isotropic conditions .;.:....,. ...,... ,..... 23 IS. Numerical simulation 5 —Steady-state drawdowa caused lay five closely spaced pits lined with sltrrtrtyy walls itt a.hypotheticat+ rmediutrr-si.d sand -and -gravel aquifer under bomogennmrs and isotropic canditiotts= >„ . .:E , ' 16. Numerical sirttulatit+n to Steady -sty diawdeNia caused by five closely spaced. water -filled pits undergoing evaparauve losses in a hypothetical, medium-sized sand -and -gravel aquifer under homogeneous. and isotropic conditions,. ......, . Y ...,..>.: ..... ........ ... :..:: ........... 25 17. atiott cif hypottlttetical head observations treed to calculate co Oa scaled sensitivities for 27.Graphs It Composite scald fiettsrcvrries lati I....................27 19. Drawdown lative to d staeen frctrn a druurmteeed circular quarry in a frartarred crystallMe-ma aquifer for three v 22 as of the hydrologic effects of mining aggregate in sand-attd-gravel aquifers 26 �dcrctavity simulated by use of fire 11?Irtrrinelli and Niccoli 29 Drawdown relative to distance from a dewatd circular quarry in a fractured crystalline -rock aquifer three values of recharge. simulated by use of the Marinelli and Nireoli analytical solution. . 21. unsaid n relative to distance from a dcwatered circular quarry in a fractured cnystall rte- k .aquifer..... fior three values of quarry penetration of the water table, simulated by use of the Marinelli and Niccoli analytical tlutirn 3li l rawdown relad a to distance trtntt a dewatered circular quarry to a fractured ystr� to -rock fifer farthree values of quarter radius, sarrtulated by use of the Marinelli and`Niccoli analytical solution ............. Deawdo n zelati tar distant P out a dewatered linear quarry in a fractured crystalline -rock aquifer quarry penetration of the water table. simulated by use of equation 7 ...... .. . 31 24. Drawdown saldistartc,e from a devvatere4 linear quarry in a fractured crystalline -rock aquifer for three value of recharge simulated by use of equation 31 25. Drawdown relative to distance from a dewatered linear query in a for t crysrtall a-rc k aquifer for three values of quarry penetration of the water able„ simulated by we of erlttation . ........ ................ :32 28. 29, Pipit 30-36. Diagrams showing: 2+ . One -percent scaled searsitivit es for eters ira the analytical solution of Marinelli an calculated for a elrcul:cr quarry in fractt d crystalline -rock aquifer under intermediate 27. mate-pearcpt scaled sensitivities for parameters in equation 7, calculated fora lineararqua a ;k aquifer under intermediate conditions :: ........ ......... . ........... ............... d:and boandary conditions for nun neat simulation if ...... ....... .,, .:, .,.......,........ 0aa. Numerical simulation 7 -Steady-state premitaing distribution of hydraulichead iat,a matured crystalline -rock aquifer under homogeneous and isotropic conditions.._.. 301,. Numerical simulation 7 -Steady-state drawderwn caused by a dewaatered quarry in It aquifer under homogeneous and isotropic conditions aused by a d catered quarry in a homogeneous„ isotropic, fxamure infinite extent, airntdated by use of the Marinelli and Niocoli anal s -Steady-state ponnining distribution of hydraulic head in a hypothetical turgid crystalline -rock aquifer underhotnogeneous and horizontally anisotropic conditions„,-,.......-.-- 39 Numerical simttlation 6 teady-atate o rawdtt urt caused by a dewatered quarry in a hypothetical crystalline -rock aquifer under hotrta eneous and horizontally anisotropie conditions....,............... 1 simulation 9 -Steady-state preminita distrilnttion of hydraulic head in a hypothetical crystalline -rock .aquifer with lateral v adetss of hydraulic conductivity ..r ... .......: .............::... 43 32 NUMrrical sitxtx ,lation Steady-state drawdown caused by a dewatered quarry in a hypothetical fractured cryne-rte acltaifer with lateral orations of hydraulic conductivity ..................... .... ............... 44 13a. Numerical sitnulatioll l0-Steady-statepremituug distribution of hydraulic head in a hypothetical l fractured crystalline -rock aquifer with ground -water flow, in deep, low -permeability fractures,..........,..--, , 45' 331x. Numerical simulation 10 -Steady-state de.,rawdown caused by a dewatd quarry in a hypothetical fractured crystalline -rock aquifer with ground -water flow in deep, low -permeability fractures...-..... 34a. Numerical simulation 11 -Steady-state 'remitting distribution or hydraulic head in a hypothetical fractured crystnilinet-rock aquifer with a hydraulically conductive fault; zone , , . 47`' 34b. Numerical simulation 11 -Steady-state drawdown caused by a dewatered qua hydraulically conductive fault zone hi a hypothetical fractured crystanine-rock aquifer., .,; Numerical simulation 12 -Steady-state prcmining distribution of h draulic hid ira as h pathetical fraetured crystalline -rock aquifer with a low -conductivity fault -cote..,.. ....,F .. ........:......;.: ,....F.;......... 49 r'cal simulation 12 -Steady -caused by a dewatered quarry intersee by a ctivity fault zone in talline-rock aquifer........,...........„ .... .............. of hypothetical head abscond ca users to c to Mate cdmpositu scaled sensitivities for simulations of the hydrologic effects crf minitag axggcegate in fracturedcrystalline-rock fractured crystalline-i Stir. Steady-state dta d crystalline -rock agrrif la, Nummricat simulation 37. Gaaiph ahowistg cotnptssite scaled sensitivities for pramete in nu TABLES 1 ₹ Steady-state ground -water budget for six numerical; simulations e sand=and ratuel aquifers. Steady-state ground -water budget for six numerical simulations of the zffe s of fining aggregate in f�t'p!t�tl�tii dad-atttl-yet aqulf ....... .: 3. Composite scaled sensitivities for parameters used itt six atttrericatl simulations of the effects of mining aggregate in hypothetical sand -and jravel aquifers:. .. 7 4. Steady-state ground -water budget f six art trterical iaatulations of pee�ttirting, cc►trditicttrs in hypothetic fractured crystalline -rock aquifers. .:.... ........ ...... .......<. .,.....,.....�.,. ...,........, ...,......, .,.,.,,. 41 5, Steady-attate ground -water laulget for six rat rtcal sitttiutlations of the effects of mining aggregate in hypothetical fractured crystalline -rock aquifer's, .,. ...,, ....... 42 ft Composite staled sensitivities for pmameters used in six numerical simulations of the effects of mining gate im hypothetical fractured crystalline -rock acfcrifc2 45. 51 52 (PITS. CONVERSION FACTORS AND ABBREVIATIONS Multipl By To obtain rreiio r iemfyrl day im;ldi meter Ifni dayIm/di Other abbreviations used in this report: L. Length T Time LIT Length per time L2/T Length squared per time DEFINITION OF TERMS (1.394 0183 3,28i 1 'rich per year gallon per minute rON tier day Alluvium - Unconsolidated gravel, sands silt, or clay deposited by streams orother moving water. Anisotropic aquifer — Aquifer in which hydrologic properties vary with directionf Aquifer —Water-hearing geologic material that will yield significant quantities of water to wells and springs. Crystalline rock — General term for igneous and metamorphic rocks in contrast to sedimentary rocks. Confined ground water - Ground inter under pressure significantly greater than atmospheric because it is confined by relatively impermeable geologic materials bounding the aquifer. Heterogeneous aquifer Aquifer in which hydrologic properties vary by location. Homogeneous aquifer - Aquifer in which hydrologic properties are identical at all locations. Hydraulic conductivity -- A immure of the ability of a unit area of geologic material to transmit mater under a unit hydraulic gradient. tt has dimensions of length per time. Hydraulic conductance e - A measure of the ability of a geologic material to transmit water per unit change of hydraulic head. It has dimensions of length squared per time. Hydraulic head -- Height of the free surface of a fluid body above a specified datum. It is a rwasure of the total mechanical energy per unit weight at a point in the fluid, isotropic aquifer - Aquifer in which hydrologic properties are Independent of direction. Saturated thickness — Thickness of that part of an aquifer in which all voids are filled with water under pressure greater than atmospheric, Steady-state hydrologic conditions - Equilibrium conditions in which hydraulic head and flow do not change with time Transient hydrologic conditions - Nonequilibriurn conditions in which hydraulic head and flow are time dependent. Trarismissivity _ A measure of the ability of a unit width of aquifer to transmit water under a unit hydraulic gradient. it is the product of hydraulic conductivity and saturated thickness of the aquifer and has dimensions of length squared per time. Urtconfined ground water — Ground water in an aquifer with a free water table. VI CONTENTS Analytical and Numerical Simulation of the Steady -State Hydrologic Effects of Mining Aggregate in Hypothetical Sand -and -Gravel and Fractured Crystalline -Rock Aquifers By L.R. Arnold, W.H. Langer, and S.S. Paschke Abstract Analytical solutions and numerical models were used to predict the extent of steady-state drawdown caused by mining of aggregate below the water table in hypothetical sand -and -gravel and fractured crystalline -rock aquifers representa- tive of hydrogeologic settings in the Front Range area of Colorado. Analytical solutions were used to predict the extent of drawdown under a wide range of hydrologic and mining conditions that assume aquifer homogeneity, isotropy, and infi- nite extent. Numerical ground -water flow models were used to estimate the extent of drawdown under conditions that consider heterogeneity, anisotropy, and hydrologic boundaries and to simulate complex or unusual conditions not readily simulated using analytical solutions. Analytical simulations indicated that the drawdown radius (or distance) of influence increased as horizontal hydraulic conductivity of the aquifer, mine penetration of the water table, and mine radius increased; radius of influence decreased as aquifer recharge increased. Sensi- tivity analysis of analytical simulations under intermediate conditions in sand -and -gravel and fractured crystalline -rock aquifers indicated that the drawdown radius of influence was most sensi- tive to mine, penetration of the water table and least sensitive to mine radius. Radius of influence was equally sensitive to changes in horizontal hydraulic conductivity and recharge. Numerical simulations of pits in sand -and - gravel aquifers indicated that the area of influence in a vertically anisotropic sand -and -gravel aquifer of medium size was nearly identical to that in an isotropic aquifer of the same size. Simulated area of influence increased as aquifer size increased and aquifer boundaries were farther away from the pit, and simulated drawdown was greater near the pit when aquifer boundaries were close to the pit. Pits simulated as lined with slurry walls caused mounding to occur upgradient from the pits and drawdown to occur downgradient from the pits. Pits simulated as refilled with water and undergoing evaporative losses had little hydro- logic effect on the aquifer. Numerical sensitivity analyses for simulations of pits in sand -and -gravel aquifers indicated that simulated head was most sensitive to horizontal hydraulic conductivity and the hydraulic conductance of general -head bound- aries in the models. Simulated head was less sensitive to riverbed conductance and recharge and relatively insensitive to vertical hydraulic conductivity. Numerical simulations of quarries in frac- tured crystalline -rock aquifers indicated that the area of influence in a horizontally anisotropic aquifer was elongated in the direction of higher horizontal hydraulic conductivity and shortened in the direction of lower horizontal hydraulic conductivity compared to area of influence in a homogeneous, isotropic aquifer. Area of influence was larger in an aquifer with ground -water flow in deep, low -permeability fractures than in a hamo- abstract geneous, isotropic aquifer. Area of influence was larger for a quarry intersected by a hydraulically conductive fault zone and smaller for a quarry intersected by a low -conductivity fault zone. Numerical sensitivity analyses for simulations of quarries in fractured crystalline -rock aquifers indicated simulated head was most sensitive to variations in recharge and horizontal hydraulic conductivity, had little sensitivity to vertical hydraulic conductivity and drain cells used to simulate valleys, and was relatively insensitive to drain cells used to simulate the quarry. INTRODUCTION Sand, gravel, and crushed stone are the main sources of natural aggregate. During the year 2000. about 9,900 pits and quarries in the United States produced more than 2.7 billion tons of sand, gravel, and crushed stone (Bolen, 20 02; Tepordei, 2002). In many places. natural aggregate lies below the water table. and the effects that mining this material may have on ground -water levels and flow directions are important concerns. The effects of mining aggregate below the water table depend upon the hydrologic properties of the aquifer system and the extent of mining, and predicting the 'ects of aggregate mining can be difficult because of the potentially complex and unknown nature of the ground -water system in which mining takes place. The effects of mining can be simulated using analytical solutions or numerical models. Each method has advantages and limitations, and results can vary depending upon how the ground -water system is conceptualized and represented. Because of the uncer- tainties associated with predicting the hydrologic effects of aggregate mining. conflicts can occur among regulatory agencies. aggregate mining operators. and the public with regard to permitting new mines or predicting the effects of existing mines on nearby wells, wetlands. or streams. During 2000-01. the U;S. Geological Survey, as part of the Front Range Infrastructure Resources Project (Xnepper, 2092), conducted analytical and numerical simulations to study the potential hydro- logic effects of mining aggregate below the water table in different hydrogeologic settings. This study seeks to provide information useful in predicting the effects of aggregate mining under various conditions and to assist in planning, managing, and regulating aggregate mine sites. Purpose and Scope The purposes of this report are to (l) demon- t>aate the potential hydrologic effects of mining aggregate below the water table under different hydro- geologic conditions. (2) compare the results of analyt- ical and numerical simulations, and (3) evaluate the sensitivity of simulation results to parameters used in the simulations. A steady-state, one-dimensional analytical solution for ground -water flow to a quarry also is derived. This report presents analytical and numerical simulations of the steady-state effects of mining aggre- gate- below the water table in two hydrogeologic settings of the Front Range area of Colorado. One set of simulations used hydrogeologic conditions and mining scenarios representative of alluvial sand -and - gravel aquifers in the plains and foothills of the Front Range area. A second set of simulations used hydro - geologic conditions and mining scenarios representa- tive of fractured crystallite -rails aquifers in the mountainous part of the Front Range area. Conceptu- alizations of each setting were used to provide insight into the magnitude and range of effects that may result from mining aggregate below the water table at real sites having hydrogeologic conditions similar to the conceptualizations. However. because the effects of mining at real sites depend upon site -specific hydro - geologic conditions that may differ from the conceptu- alizations, the effects of mining at real sites may differ from results presented here. Analytical simulations were used to predict the extent of lowdown caused by a dewatered pit or quarry as a function of different hydrogeologic condi- tions (horizontal hydraulic conductivity and recharge) and mining extent (depth and radius/width) within a homogeneous, isotropic aquifer of infinite extent. Numerical simulations were used to predict the extent of drawdown caused by a dewatered pit or quarry under heterogeneous. =isotropic conditions with hydrologic boundaries and to simulate complex or unusual conditions not readily simulated using analyt- ical solutions. Sensitivity analyses show how each parameter in the simulations affected simulation results. 2 Analytical and Nu eeel Simulation of the ineedyaide Hydrologic Effects of Mining Aggregate in Hypothetical Sentt'and-t3ravet end Fractured Crystalline -Flock Aquifers Acknowledgments 'Ran ks are extended to Curti Coppttge of Aggregate egate Industries for providing access to mint sites where useful mining information was obtained. Thanks also are extended to Dan Knepper and Roger Melick oldie Geological Survey for their assis- tance in developing the conceptualizations used to this study- Technical assistance front Ned (Banta. Ken Watts, and Alan Burns oldie #_t.S. Geological Survey, was very valuable to the completion of the study and is gratefully acknowledged, FI D O EOLO IC SETTINGS The Colorado Front Range area (fig. 1) straddles the boundary of the Southern Rocky Mountains and the Colorado Piedmont section of the Great Plains in northeastern Colorado (lieattteman, 10411). The Colts ado Piedmont separates the Rocks Mountains front the.11lgb Plains and contains shop of the State's popu- lation- The topography of the Colorado Piedmont part of the Font Range area generally has low relief (tens of meters) in comparison to the topography of the WYOMING COt_vt0a mountainous part. which has relief of hundreds of meters. Because of diferertcrs in topography, aspect (sun exposure), and altitude between the Colorado Piedmont and the adjacent Front Range of tite Rocky Mountains. the climate of the Colorado Front Range area is varied. The climate of the Colorado Piedmont part of the front Range area is semiarid temperate continental asitli average annual precipitation that varied with geographic location and ranged front about 25 to 50 cm/yr during 191,1=9Jtl (W'esterrt. Regional Climate Center, 1997). Average annual pan evapora- tion for the same area ranged Wm .about 14(} to Kt) cintyr during /946-55 atotwon and Banta. 1995), By contrast, the climate of the Rocky Mountain part of the Front Range area is s:abdturnitt (Fennentan, 1940) with average annual precipitation that varied with geographic location and taped from about 4(1 to 65 cm/yr during 1991-2 (Western Regional Climate Center -1997). Average annual pan Mprtraa- tion for the Rocky Muutttaitt part of the Front Range area ranged front about 125 to 165 etanty+r during 194t,- 55 (Robson and Banta, ft)95). The Colorado From Range area is -drained primarily by the South Platte River and its tributaries (fig. 1), 5[0 MILES Figure Modes map al Colorado Root Range area. tiVDR tGuo ,t7Glc SETTINGS 3 Aggregate ironing in the Colorado Front Range area takes place primarily within two dixtinLt liydro- ger lojie settirtg.s. t I t alluvial sand and grand deposits in the C'oloradr, Piedmont and (2) fractured crystalline rock in the Rocky Mountains. About two-thirds oldie aggregate in the Front Range area is sand and gravel from alluvium and about one-third is crushed stone from hotbed crystalline rock (Wilburn and Langer, 20001, Sand -and -Gravel Aquifers Alluvial deposits in the Colorado Front Range area can be separated into four major Inndfornti, (Cohort. 1078; Ct>rtsby. 107$; Trimble and Machette. 1979) fig, 2). From highest (oldest) to lowest (youngest) tire major a11t v ial tandforxn5 are (I) allu- vial fans and pediments, ill high dissected terraces, (3) high continuous aernices, and (4) flood plain and line terraces. Sand and gravel are mined for aggregate in each of there Iandforrns, brat because mining does ant commonly penetrate the water table in alluvial pant , pedirt,ents., or high dissected terrace. only flood t laity , low Lterrace,s. and high continuous Incomes are reprecr'ttead to this study, Flood -plain. low -terrace, and. *high -continuous -terrace deposits air eoniprn ed of clay. silt. sand, gravel, and cobbles; but ys-erliinents consist primate ly c,t'sand and gravel in area: where aggregate mining Ma:1M alluvial,sediments commonly tare stratified. hat stratification is variable, The sandaand,gravel aquifers of flood plaint,, low tertarces,, and high continuous termer, range to width from about 700 to 9,000 >lat and have a saturated thickness stf 0 to niece than 30 en (Sheet. 4 in Robson, 1096; Robson'. Arnold, and Witty, 2000u and 1a: Rerbrson,1-ieany, and Arnold. 2000a and Lit= The trop t,1` the aquifer in the water feeble, and the bane of the aquifer is bounded try sedimentary bedrock that, can averages is 2t111 --•MILD times less permeable than the alluvial sediments. which have hydraulic conductivi- ties ranging frrr u about I tl to 1,0tli 0 hid (Robson. 1989: Wilson, 19551. Average ►meter.=table gradients in alluvial valleys generally range from (1.002 along: Figure 2. Atlaiv al Push myatailine-rects landlrrirm in the Colorado F'r€rnt Snow area (modified front Crosby, 1978)• Analytical and tmharswioat'stmulattnn at the SteactrStete Hydrologic- Ctte11s mil !editing Anwmigale In -Hypothetical rd- Gtauat gyred Fraelnt d. Cryr tone -Res ,Agoltere downstream reaches of principal rivers to 0007 along reaches of major tributaries nearer the mountain front (Sheet 3 in. Robson, 1996; also Robson, Arnold. and Heiny. 2000a and b and Robson, Heiny, and Arnold, 2000a and b). Water -table gradients generally are steeper along hillslopes between valleys, Ground- water flow in the aquifers generally is down the valley and toward streams. Aquifer recharge is from infiltra- tion of precipitation and irrigation or from inflow of water front adjacent alluvial aquifers or underlying bedrock aquifers (Robson and Banta, 1995). Precipita- lion recharge to an alluvial aquifer in the Colorado Piedmont near the Front Range has been estimated to be about 5 percent of the total annual precipitation (Buckles and Watts, 1988; Goeke, 1970). Discharge from the alluvial aquifer occurs primarily to the South Platte River and to wells (Robson and Banta, 1995). Sand and gravel are excavated using both dry and wet mining techniques (Langer. 2001). If the exca- vation does not penetrate the water table, gravel is mined dry and can be extracted by using conventional earth -moving equipment such as bulldozers, front loaders, and track hoes. If the excavation penetrates the water table and thepit is mined dry. water will be pumped or otherwise removed from the pit. Water removed from the pit lowers the water table in the vicinity of the pit and may affect water levels or flow in nearby wells, wetlands, and streams. In some cases, slurry walls are constructed around the perimeter of a pit to isolate it from the surrounding aquifer. If the excavation penetrates the water table, and the pit cannot be drained, gravel may be mined wet by using draglines, clamshells, bucket and ladder, or hydraulic dredges. Fractured Crystalline -Rock Aquifers Precambrian metamorphic rocks (including quartzite, schist, gneiss, and amphibolite fig. 2) and igneous rocks (including granite, granodiorite, monzo- nite, diorite, and pegmatite) form the mountains of the Colorado Front Range in the western part of the study area (see summaries in Colton, 1978; Trimble and Machette, 1979), Bedrock in the Front Range is broken by numerous faults that differ greatly in size, orientation, and attitude. Away from fault zones, many metamorphic and igneous rocks are hard and dense, a characteristic that makes both rock types important sources of crushed stone for use in Front Range communities. Within fault zones, the crystalline rocks are extensively fractured and faulted. Faults or fault zones may be more permeable than the surrounding rock and provide a conduit for ground -water flow, or they may be mineralized and constitute barriers to flow. Ground water in fractured crystalline -rock aqui- fers is present in discrete fractures and assures within the rock rather than in continuous, interconnected pore spaces as in sand -and -gravel aquifers. Fractured crys- talline -rock aquifers may be discontinuous at a scale of a few meters or tens of meters because fractures are not locally interconnected. However, fractured crystal- line -rock aquifers may be continuous at a regional scale because some local fractures may be connected to a regional fracture network: Water left's measured in wells in an area of the Front Range mountains suggest the fractured crystalline -rock aquifer is uncon- fined and has a high degree of hydraulic connectivity at a regional scale (Lawrence and others, 1991). The permeability and porosity of fractured crystalline -rock aquifers have been shown generally to decrease with depth (Daniel and others. 1997; Davis and Turk, 1964). In the Colorado Front Range, test data indicate the permeability of the fractured crystalline -rock aquifer tends to become exceedingly small at depths. 60 to 90 m below land surface, although open fault zones may extend to greater depths (Snow, 1968). Because permeability generally decreases greatly at depth, the effective saturated thickness of the aquifer also may be 60 to 90 in or less. The permeability of fractured crystalline -rock aquifers depends upon the spacing, aperture, and connectivity of fractures in the rock. and permeability generally is several orders of magnitude less than in unconsolidated sand and gravel deposits. Heath (1983) and Freeze and Cherry (1979) indicate hydraulic conductivity in fractured -rock aquifers generally ranges from about 0,0005 to 15 meters per day (mid). Folger (1995) reports hydraulic conductivity ranges from about 0.002 to I trod for the fractured crystalline - rock aquifer at a site in the Front Range mountains. Hydraulic conductivity of fractured crystalline -rock aquifers has been estimated to be greater beneath valleys and lesser beneath hilltops than that beneath intermediate topographic terrain, which suggests that fractures may be more numerous beneath valleys and less numerous beneath hilltops (Daniel and others, 1997). Fracture orientation may control anisotropy in fractured crystalline -rock aquifers. Water -table gradi- ents in the fractured crystalline -rock aquifer of the HYDROGEOLOGIC SETTINGS Front Range mountains generally am steep. Recharge to the fractured crystalline -reek aquifer has been esti- to range from 0 to 21 percent of precipitation th an average of 3.2 percent (14ofstra and Hall, 1975) to 10 percent (Mueller, 1979), n theColorado Front Range, rock quarries typi- ;ally are mined dry (Langer, 21X11). Although quarries may penetrate the water table. the discharge rate to quarries commonly is less than the rate ofevaporation., and active dewatering measures are not needed. The quarry may drain freely, To produce aggregate, the rock is first drilled and blasted. Blasting commonly breaks the rock into pieces suitable for crushing, and the blasted material is extracted using eonventional nth -moving equipment such as bulldog. front loaders, and track hoes. Material is transported, either by truck or conveyor. from the mining face to the processing plant where it is crushed, washed. and sorted by size. GROUND -WATER HYDRAULICS AND MATHEMATICAL METHODS To evaluate the effects of agate raining on the surrounding water table, ground -water flow was simulated with analytical and numerical solutions to the aund-water flow equation. A general form of the equation describing transient (time -varying) three- dimensional ground -water flow can be written as (Konikow and Grove, 1977: McDonald and Haaaugh 1988)» o�x ah is aquifer hydraulic conductivity in the x -dire on (1-2/ 11 K is aquifer hydraulic conductivity in the y -direction (l a), K.t is aquifer hydraulic conductivity in the z -di tion (O/T), 8 is aquifer saturated thickness (L) Is is hydraulic head (L), S is storage coefficient (dimensionless ), W is volumetric flux per unit area from a hydrologic r sink as a unction of location and This equation assttr es comp ssible fluid taf constant density is flowing through a hetero enetatas an scatropic aquifer according to Fancy's law 1994). It also assumes the principal axes of the hydraulic conductivity tensor are aligned with the x, ►. and z coordinate axes. respectively (McDonald and Harbaugh, 1988). Additional details of the ground- water flow equation and its derivation can be found in numerous texts and reports (Freeze and Cherry, 1979; Lohman, 1979; Huyakorn and Pinder, 1983: McDonald and I arhaugh, 1988; Domenico and Schwartz, 1990: Anderson and Woessner. 1992: Fetter, 1994). The ground -water flow equation +eon be solved nor the dependent variable head (Is) by analytical car numerical methods. Analytical solutions use ►lgebra methods to derive closed -form solutions to the gerund- water flow equation, whereas numerical solutions use mite -difference or finite -element numerical methods to solve the ground -water flow equation. Analytical solutions to the ground -water flow equation are mast useful for evaluating simplified ground -water systems and often assume a homogeneous an d hydraulic -conductivity distribution ,)soa r and infinite horizontal extent or limited boar conditions. Analytical methods can be use mating mine inflows and drawdowns during stages of mine planning when site -specific data may not yet be available (Marinelli and Niccoli, 2000). The applicability of an analytical solution depends on the erctent to which the real problem under consideration is consistent with the simplifying assumptions of the analytical solution. Analytical solutions that assume infinite horizontal extent can be useful in predicting drawdown in, real aquifers of finite extent when ,; ttifer boundaries lie beyond the cone of depression in the water table (area of influence) caused by the pit. When boundaries lie outside the area of influence, the aquifer wiltin the area of influence responds as though it were nertcer Stnwlutron of the needy► 14yrd ttntng A In14i parthettcal nd.end-mil of infinite extent because no boundaries are contacted. Numerical simulations are useful for evaluating more complex flow systems such as heterogeneous or aniso- tropic hydraulic -conductivity distributions, multiple boundary conditions, and transient conditions. Numer- ical methods may be required during advanced stages of mine planning when more detailed geologic and hydrologic data are available fora site (Nlatinetti and Niccoli, 2000). Analytical and numerical methods can be coded into computer programs to facilitate their use. Both analytical and numerical simula€ion. atis were used in this study to evaluate the steady - lime -invariant) effects of mining aggrea, to on er-table conditions. A steady-state two-dimen- sional analytical solution to theground-water flow equation by Marinelli and Niccoli (2000) and a steady- state one-dimensional analytical solution derived during this study were used to estimate the extent of drawdown around a mine in .a homogeneous, isotropic aquifer of infinite extent. The U.S. Geological Survey modular ground -water model, MODFLOW-2000 (Harbaugh and others, 2000), was used to evaluate steady-state effects of aggregate raining under more complex hydrogealogic conditions. The steady-state two-dimensional analytical solution of Marinelli and Niccoli (2 000) estimates radial ground -water flow toward a circular mine pit. The analytical solution for head in the aquifer adjacent to a circular pit of radius rp is given as: where b is saturated thickness distance from pit ceo Iti, is saturated thickness above the pit base at r5 (at the mine wall) [L]4 W is distributed recharge flux [t,/TI, Ky is horizontal hydraulic conductivity of surrounding geologic materials IL/T]y r� is radius of influence (maximum extent of the cone of depression) [Li, r is radial distance from pit center [Ll, is effective pit radius [L) (fig. 3). Given input values of hi), W, K5, rp, and initial (premising) saturated thickness above the pit base (5= ht,,), the radius of influence (et) can be determined through iteration by setting r equal to r; . Once rr is pit base at f=igure 3. Conceptual diagram of the Marinelli and Monk an (modified from t aririe li and Niecoli, 20O3). adiai GROUND -WATER HYDRAULICS AND MATHEMATICAL METHODS determined. It can be calculated for any radial distance from the pit, and drawdown can be calculated as it, - kin addition. the inflow rate. Q R;/Th through the pit wall can be calculated as: Q = Ww(r—r,') (3) The analytical solution of Marinelli and Niccoli (2000) is valid for ground -water flow systems that meet the following assumptions: • The geologic materials are homogeneous and. isotropic; • Ground -water flow is steady state. unconfined, hori- zontal, radial, and axially symmetric: Recharge is uniformly distributed at the water table and all recharge within the radius of influence is captured by the pit; • Pit walls are approximated as a right circular cylinder; • The static premining water table is approximately horizontal; and • The base of the pit is coincident with the base of the aquifer. and there is no flow through the pit bottom. Marinelli and Niccoli (2000) also present an analytical solution for upward ground -water flow through the bottom of a pit that partially penetrates an aquifer, However: inflow to the bottom of a pit is not considered in this report because (1) analytical solu- tions are used only to calculate hydraulic head at the water table, which is independent of ground -water flow through the mine bottom in the solution. (2) the bottom of aggregate mines in sand -and -gravel aquifers in the Front Range area generally are near the base of the aquifer, and (3) hydraulic conductivity of fractured crystalline -rock aquifers generally becomes exceed- ingly small with depth, which limits inflow to the mine bottom. For pits that do not meet these conditions, consideration of flow to the mine bottom may be important, A steady-state, one-dimensional analytical solu- tion is derived for ground -water flow to a mine exca- vated into a steep hillside such as in the mountainous part of the Front Range area. The derivation of the one-dimensional solution is similar to the Marinelli and Niccoli (2000) solution, but the mine is repre- sented as a straight line along a hillside rather than a circular pit. The mine in this situation intercepts only the upgradient ground water within the hillside. Ground -water flow toward the mine at distances upgradient from the mine wall can be expressed as: Q = Koh (4) where Q is flow per unit length of the mine [L2/T], 14 is horizontal hydraulic conductivity of surrounding geologic materials [LIT]], h is saturated thickness above the mine base at distanccx from the mine wall [L], and x is distance ttpgradient from mine wall If all ground -water flow to the mine is assumed to originate from uniform distributed recharge (W) within the drawdown distance of influence (x) of the mine. then flow toward the mine also can be expressed as: Q=W(x, -r) (5) Substituting equation S into equation 4 and inte- grating from the mine wall to distance x gives J (x;—x}ct<r = 5hdh where (6) /r,„ is saturated thickness above the mine base at the mine wall N. Carrying out the integration leads to an analyt- ical solution for head in the aquifer adjacent to a linear mine that is given as: 17= h + . -F-'-[2x.x — x' ] (7) s a Analytical and Numerical Simulation of the Steady -fie Hydrologic Effects of kilning Aggregate to Hypothetical Stad.and4ravel and Practised Crystalline -Rock Aguttws Giinput vatu oaf J �.1,14. Kh, and initial f prcmning) aatr ratabove the base of the mine rift = afih,,). the distance df ithfluence txt) can be calculated nix kctly by setting x equal to x, and re- sins equation 7.Once :c1 is determined, it can be Iculatecl for any distance upgtndient from the mine _ and drawdown can he calculated as 8„— kin itian, the inflow rate per unit length of mine,Q can be calculated as: Q fltxi The analytical solution fora l lid for ground -water flow systems Ilcithg assumptions gic materials are homogeneous and topic` td -water flow is steady st ulna a Reclean and all is ptwed by tlnt: aline; The uphill mine wall is approximated ns a straight litre, unctfined. hori- mine wall• lie static remin n hori�►ontnl� heel otn, ly distributed at the water table ithin the distance of influence able is approximately the pit is coincident with the base of the aid there is no flow through the mine MODFLOW' p (H ugh and other`s, 2t was uNed to estimate the steady-state extent of draw down near a thine and groundwater inflt►w to a mine under conditions that consider heterogeneity, anisot- ropy, and boundaries. MODRIAV-2000 solves the tntnsient,ground-water flow equation by using implicit finite -difference methods and is based on a three- dimensional.block-centered. finite -difference grid. Aquifer properties can be heterogeneous and anises epic provided the principal axes of hydraulic conduc- tivity are aligned with the coordinate directions (Harbaugh and others. McDonald and Hatimigh, 1988), and aquifer layers can sinhula as confined. unconfined, or a combination of lhnth Cataugh and others, 2) r cart simulate, sev eral ty pes of hydrologic sources including aquifer t hank§ a transpired drains, and rivets, and it can simulate eithers state or transient conditions. d sinks may- IMULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE Two hydrogeologic settings in the Colorado Front Range area were simulated using analytical and :rival methods. The first set ref simulations used ptualizations of ag regtt mining in d -and- ifers, anc! the set:ond set of simulations used eptualizatiansogahte,mining in fractured line -rock aquifers, Analytical and numerical mulations wer cued to imate the steady -Mate hydrologic effects of tninin , Under steady-state conditions, discharge to a mine reaches equilibrium with the surrounding ground-waters}=stem, and the extent of drawdo n caused by dewat ceases to increase. Therefore, steady -slate predict the maximum potential effects of time. To predict short-term efets. transient varying) simulations are necessary. Steady-st simulations of pits in sand -and -gravel aquifers may overpredict the effects of mining if active dewatering; of the pit ceases before steady-state conditions are reached. The hydrologic effects of pits in sand -and - el aquifers after active dewatering ceases (pits d with slurry walls or refilled pits undergoing ive loses) likely reach steady-state conditions pits may be left open indefinitely. The effects of quarries in fractured crystalline - likely reach steady -slate conditions monly drain without the aid of measures (Kncpper. 2002) and may indefinitely. Predicting the transient ft of mining is beyond the scope of Simulation of Pits in Sand -and - Gravel Aquifers of d ,'vet ins of input paramet reining in sand -and -gran .sed on data reported in the literature Hydrogeolo, is Settings . Definitions of nu extents (area and depth) were defined based on m OF t+l or MINIM A GA's footprints ShOWil by Rctl on (1551(3) and Robson. Arnold, and Heiny (2000a and b) and _Robson, Ilcin, , and Arnold (000a and h) and ansite data. Interme- diate parameter values anti boundary conditions were used in simulations to represent average hydmgeo- logiccoalitions and ntiningestents. Parameter values and boundary conditions were then varied over a range of values and conditions typical for pits in sand -and- gavel Itqutfers to detcrrnine the potential effects of mining over wide range of conditions. Intermediate hydraulic conductivity was defined in the simulations as 100 mid and intennet iate recharge was.detined as 0.0001)5 imid. which is about 5 percent ofthe average annual precipitation for the Colorado Piedmont part of the Front Range area. intermediate pit penetration of the water tahie was defined as (r m, and intermediate pit radius wits defined as 100 nt.. Anal idol Simulations and Sensitivities The analytical .dilution of Marinelli and Niccoli ( X1) was used to solve for the radius of influence (r;) and arwturated thickness (It) alxtve the base of a o ews teed pit in a honrogenneous i tropic sand -and -gravel el z O 10 r,= 1,0415 aquifer of infinite extent. t°lurivontal ItydrauIic cnncluc- t s-ity (4/41. rec e (1, 14. initial saturated thickness above the pit base (8 = 1O, and pit radius (re) were varied independently over a range of votlue s typical for pits in sand -and gravel aquifers in the Front Range area. By varying the parameters independently, the effects of each parameter on simulation results were aluntied. and sensitivities lilt` parameters ters were calcu- lated. Because initial saturated thickness is measured relative to the pit base, li„ also is equal to the depth to which the pit penetrates the water table. The water level in the pit was defined at the base of the pit. Figure -7 show drama 'lei, — !°i ) and radius of influence measurer, from the pit wall (r; it,) caused by an dewntered circular pit in a sand -and -gravel aquifer for diffeient values of -4 (10, 100. and 1,001 midi. W 0000025, ti. 5, and 0,0001 mod), !r„ (4. Cy. and 8 m), and rr, (25. co.'Iand 500 rri). Results indicate radius of influente front the wall of a lewa- teed pit in a homogeneous. isotropic sand -and -gravel aquifer of infinite extent was 4,544 m wider interme- diate conditions (4= IQ() rt tl, W = 0.00005 trod. 14, 6'm. rr - 1001n), Radius ttf influence increased as 4, and r , increased and as 14' det asecl.. j= 4,544 alit i r ex own STANCE FROM PIT WALL, IN METERS Figgie 4, wit:town rotative to distance horns e °( (erred pt in a sandenkravel a bet tar the value at taoneontat hydraulic cCnnductiity, simulated by use of the Marinelli end Niceott (MOO) analytical solution, Li EXPLANATION 001,01,,fir 0R WON We, g(�10O,014O5 'maim ti MyE. us 01 mittlence 010n tsi 1,O1.' at w 0 00005 . Ip 100 Ito 000 10 Analytic& and Numerical Sheufaltan of the Sleady s ale Hydrologic Effects of Minim Aggregate, in Hypothetical Sendasavef and Practised Chystallini4teek Aquifers DISTANCE FROM PIT WALL, IN METERS Figure S drawdvwrl relative to distance tram a dewatered pit in a sand,and.gtavel aquifer for three values of redli e. use of the Marinelll and Ntt tl; (2000) analytical solution. z 4 ., 0 Abe 10 100 1,000 w 4,444 DISTANCE FROM PIT WALL, IN METERS Figure 6. Drawl wn relative lei delance tram a dewatered pit in a sand -and -gravel aquifer Ir the water table, simulated by use vi the Mattnelli and Meech (2000) analytical solution, ut EXPLANATION Kt, IMF loillnuAte 04aiiactivllys melare par ha ill irela nr da' wmla,1 Irt matt. rp Pit ruaiue. at meters ►,Rad. at 0111101.0 ffam pb wall, in meters W Rechafgo, , 'maters par day FIXED PARAMETERS fch 100 t"d 0_noonS rp tOO ues oI pit penatation at SIMULATIt3it4 OF THE W/GA LO i0C EFFECTS AGGREGATE DISTANCE FROM PIT WALL, IN METERS EXPLANATION. Kare mist hydraulic con y, In mum pot day pit ryeinelmi ear of waist tabs, Di Mid. Pt enclitic to tom. Rodiiiif err Inkx..0 IRr,rr pit .4 movers Rect.ge, mmats tor day FIXED PASAMEFEFIS !i'p,100 Me 0. hr Figure 7. DrawdoLVri relative to distance from a dewatered pit to a sartd-anal-grad aquifer for three values o1 pit radius, simulated by use of the Manned and Woolf (2000) analytical solution. One -percent scaled sensitivities were calculated for each p trtmeter used in the analytical solution of lv7a fn Mli and Nli,~cali (2M°) to rietertnine the effect of rtacit parameter on simulation results tinder interme- diate conditions. One-pint,scaled sensitivities. Is.ryare cafcaala►ted as (Hilt, ('MI): 100 } , is the simulated value ass irciated with the lilt tibseraratrun a i is tire.,jilt estimated parameter, di.# is the sensitivity of the simulated value associated r�Jx vs ith the tilt observation with respect to the , jth parameter and is evaluated aril.: and 1 is a vector that contains the parameter values at which the seiisitivities are evaluated In (iris plc .ttrtrn. is is the radius of influence. and li is the parameter I K { 1i' tr, , or r ,l fiat which sensitivity is calculated. Resulting sensitivities have units of meters and are the change in radius of inllu- arcs caused by >a l -percent change in the parameter vniete. Parameters with high sensitivities affect simu- lated radius of nrflttence more than parameters with ltrw Sensitivities. Therefore. parameters with high sensitivities may be mare important to accurately define than parameters with low sensitivities at real sites with conditions similar to those in the analytical siruttlatit'rns. Because one -percent scaled sensitivities depend upon the parameter valttesat which they are evaluated, sensitivity results will be different for different hytltrgeralr rgic conditions and mining extents. Results of analytical sensitivity analysis (fig. g) under inteimiediate conditions (A5 100 mid. )l - 1) )05 mid, >Ir a 0 tit, r = 100 itt) indicate radius of influence was mist sensitive to chariges in pit pelretrticrtt of the water table and least sensitive to changes in pit racilit- Radius I 1 ittl'ltt was equally sensitive to changes iii horizontal hydraulic comhictivity and recharge however, the parameters had opposite effects on 12 Analytical and Numeric& Simulation of the Slend a Hydrologic rands of Nanny Aggregate in Ilypainntkol ndi simnel end Fined Cryslstitee pieck Aquifers PARAMETER ri td 1i, ifrtei rCeettOterfDP10 Figure 6. One-pereentscaled sensitivities for parraninterS irithe anal3 i� ld f?000l, eainatat eel tech apit a sand -and -gravel aquifer under I .100 raid, W.0.00005 rods tiv= 6 m,: 100 rn)r #.s; because tile) are. inversely vine- ytical solution. Radius of influence Kirizonial hydraulic conductivity d and as cede decreased. Numerical Simulations MODFL `-20(X) (l lar xiugh and others, 20(t)) was used to compute (1) hydraulic heads in a hypo - al surd -and -gravel aquifer under steady-state, ring conditions, (2) steady-state dmwtlown d by a dewatered d pit in the sand -and -gravel underdifferent hydrngeologic ct nditi s, ow to the pit under different hydrogeologic titans. to addition. theobservation and sensitivity apiihililies (Hill arid others. 211(X}) (If M FLOW— 21111 mere used for compute sensitivities for simulation input parameters. gecatrse simulations are of hypo- thetical atiuilers, model calibration was not necesary. However, genet rliz d aquifer data from real sits were teed to guide develttprnrrri of simulated premining conditions. Six numerical .simulations of the hydro- logic effects of mining aggregate in hypothetical sand - rind -gravel aquifers -ale presented as unllties Simulation I The hydrologic effectsof a dewa- Ieredpit in a medium-sized (iitxniat 2,50 tn wide) allu- vial valley under homogeneous andisotropic conditions are simulated. Comparison ti("simulation I l sotui *timed Itti tit t lesttlt r l t the f tittrts. 2 —The hydrologic effects Ufa dewtt- treed pit in a medium-sized alluvial valley iintler homogeneous but alliSOMVIC cortdidrin are aimu lured, Comparison of simulation 2 to simulation I shrwrs the effects of vertical anisotropy., Simulation 3 —The hydrologic effects of clewu Wed pit in a ittrge (about 5,000-tn wide) alluvial valley tinder homogerienus and isotropic conditions are simulated. Comparison of simulation 3 tosintula stern 1 shows the effects ofinctsrsirag aquifersizeand changing boundary ctttlditionr: Sir tilutirtn 4 —The hydrologic effects t►f a ell -. treat pit in a small (about 1,200 -in wide) alluvial valley under homogeneous and isotropic conditions art simulated. Comparison of, simulation 4 iii cimultr- risen t shows the effects of decreasing iigtiifer size ad changing boundary conditions. Simulation S=The lsyd,tslogic effects of the eat ly spaced pits lined with laity walls in a medium-sized homogeneous. isotropic ss nd-and- gr'avel aquifer are situulatett, ration 6 —The ltydshlugic effects of live (lonely spaced. water -fillet) pits undergoing era rt iit a medium-sized homogeneous. isnurPic std -erase) aquifer are simulated: SMAIILATON OF Tai C � OF MINING AGGREGATE Simulation 1 —Pit In a medium -sit„ homogeneous, isotropic aquifer Simulation 1 shows the potential hydrologic a of dewatering a pit in a medium-sized alluvial The simulation uses the intermediate values of orrtal hydraulic conductivity. recharge, and pit he analytical simulations, but a shallow pit so that water -table penetration is constant. among all numerical simulations, including simulation 4 (pit in a small sand -and -gravel aquifer), which is too shallow for the intermediate penetration depth. Medal design A sand -and -gravel aquifer is represented using two layers in the numerical model (11g. 9). Layer I (top layer) is 6 m thick with about 2 to 5 in of saturated thickness. Layer2 (bottom layer) is 2 m thick and is fully saturated. Both layers are simulated as convert- ible. which allows hydraulic head to be computed for either confined or unconfined conditions. Total premi- fling saturated thickness near the pit is about °b m: The model grid has 35 rows and 80columins (fig. 10) with at cell size of 50 mx 50 to near the pit and 100 m x ltd to at a distance 600 nt from the pit. The alluvial valley represented by the model is 7.[x')0 to long and about 2,500 in wide, which is representative of medium-sized alluvial valleys in the Front Range area Hydraulic gradient is about 0.005 along the length of the valley. Horizontal hydraulic conductivity in both layers is 1110 mid, and vertical hydraulic conductivity is equal to horizontal hydraulic conductivity. The upgradient and downgrrtdient ends of the valley are simulated as constant -head boundaries. The sides of the valley are simulated as general -head boundaries to simulate inflow to the model from a thin part of the alluvial aquifer beyond the boundaries of the valley. General -head boundaries are defined to simulate flow through a saturated thickness of 2.5 m under a,gnidient about twice that of the downvalley gradient. General -head boundaries also are defined using a hydraulic conductivity value of 10 m/d to simulate finer grained and somewhat less permeable material at the valley edges. The aquifer base is simu- lated as a no -flow boundary at the bedrock surface. A specified -flux boundary with a value of 0,0005 raid is used to simulate areal recharge from precipitation. Water flow between the river and the aquifer is simulated by using the River package of MODFLOW- 2000. Definition of riverbed conductance is based on a river 10 to wide with a stage 4 m above the base of the aquifer and a riverbed 1 m thick with a hydraulic conductivity value of 1 mid. The pit is simulated in layer I as a 200-m wide square with a water: table penetration of 4 m by using the Flow and Head Boundary package (Leak and Lilly, 1997) of MODFLOW-2000. Initial heads in the pit cells are set to match those of the steady-state conditions of the preminng aquifer, and final heads for the pit cells are set 4 nt below the water table to simulate drawdown in the dewatered pit. Horizontal and vertical hydraulic conductivity of pit cells is increased by a factor of 1,000 to represent the open area of the pit where sand. and gravel were removed. Moults and comp :Won to andytical The simulated steady-state prentining cfistribu- taon of hydraulic head in the aquifer is shown in figure 1 lo, and steady-state drawdown near a dewa- tered pit in the aquifer is shown in figure Ills Steady- state drawdown computed using the analytical solution of Marinelli and Niccoli (2000) for a dewatered pit in a homogeneous, isotropic sand -end -gravel aquifer of infinite extent is shown in figure 11c. Results of the analytical simulation were computed using the same input values of horizontal hydraulic conductivity, recharge, pit penetration of the water table, and pit. radius as the numerical simulation. Lines of equal drawdown computed by the analytical simulation are concentric circles centered around the pit, and area of influence computed by the analytical simulation (defined by the limit of 0.1 m drawdown) hays,a radius of 3,187 m, measured from de pit center, Lines of equal drawdown computed by the numerical simulation are asymmetrical because of boundary effects, and area of influence computed by the numerical simulation (also defined by the limit of 0.1 m drawdown) has a maximum extent of about 3,200 on, measured from the pit center. Area of influ- ence in the numerical simulation is smaller in general than in the analytical simulation because pound -water flow to the pit in the numerical simulation is contrib- uted by many sources, including precipitation, river leakage, and inflow from constant -head and general - head boundaries, whereas ground -water flow to the pit 14 Analytical and Numerical Simulation of the Stendratate Hydrologic Meets of Mining Aggregate In Hypothetic and Fractarad Crystalline -Rot* Aqulfam Sand.an&Gravel General -bead teary 7 ha -j K Hcharge pit IR -- J Not, , boundatY EXPLANATION H-icturnntal lwc1rsutic c1Gt'ducittigly of layers i ant 2 Vertical 1lytribulvc oorbducsivtty of foyers I and 2 Kok,.T Hydraulic conductanim controlling flow betwonrt cxterrial &Dural and aquikr_r Kfti = Hydraulic crirlr '#nce cantrollnq flow tieliteciert rrvvr anti aquifer RI -03 = nova -arid- read boundary General -bead boundary Figure 9. 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UM• ci a a ■ U EXPLANATION Active- ecru Constant -read caul C ne l-fiead Eels Rivet cell Flayrard-tend boundary cell used tc Weats Psi lnaclvo cci 1.000 sate° } 3_o00 MEn s& 1 fa,aoa FEET Figure 10. Finite -difference grid and boundary ry conditions for numerical simulation t (pit in a hypo- thetical, medium-sized sand -and -gravel aquifer under homogeneous and isotropic cond+tions). SNAULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE is EXPLANATION h a Numerical simulation 1- Steady -slat e prea► dng thstibution of hydraulic head In: a hyp medium i ed sand -and -gravel aquifer under homogeneous and isotropic condtkins. EXPLANATION u 1t of mpg drawdom, metiers Cure 1b. Nunrescal simulation 1., medium-sized sand -and -gravel druwdown caused by a dewatered pit on a nypothet- homogeneous and isotopic conditions. Analyticel Gravel and simulaHydrologic moots of tstaitlutettc 31YJ31lODV °NUNIIR 4? Si33143 01 0010 OAH Hi. A mourtnivs le lk?w (000Z) llo %.14 •pu oldo ! 'snows . 4mM _ il9 ul I I III to *se Aq pepowle leap* ellurjul o Je#rn►bu levcur6-pue 4 JOt009p S poem uoopomp elm-Ape0tS ° L L moths 0d3 0004 000"e 0 NOIJMIIV 1 in the analytical simulation is contributed only by distributed recharge from precipitation. Drawdowta in the area between the pit and the river in the numerical simulation is less than draw- down in the analytical simulation because the river in the numerical simulation acts as a recharge boundary and maintains hydraulic head in the aquifer near premising levels at the river, Although the river contributes flow to the pit and acts as a recharge boundary in the numerical simulation, some draw- down (0.1 d cur arr ss the river because ground wvater Clow tree pit through the underlying aquifer in layer rawdown awway from the river in the numerical simulation is greater than drawdown in the analytical simulation because the area of influence in tl numerical simulation contacts the boundary of e aquifer, which limits if tawv to tf arga of influence and causes hydraulic head to drop more substantially. Under prerni ling conditions. the largest compo- nent of recharge is from inflow at the upgradient end of she aquifer* and the second largest component of recharge is from inflow along the sides of the aquifer. a� t ti ll valactote in en ground-waterbudget brats nut Ground ,tee inflow fam boundary at upgmsdient etul cif aq nd-ester in low tit general -heart long &ides of aquifer Total Precipitation is arelatively small component of recharge, and river leakage to the aquifer is the smallest component. Discharge at the dowagradient end of the aquifer under premining conditions is similar in magnitude to discharge to the river. The complete ground -water budget for portingcondi- tions in simulation 1 is shown in table 1, and complete ground -water budget for the elf i c dewatered pit in'Simulation I is shawl ground -water budgets give attract to the aquifer and discharge fro given in the tables indicate arch category. Recharge to the ac and -water inflow from the upgradiennt end of the aqu from general -head boundaries re c l3) river leakage to the a distributed recharge from precipitation. from the aquifer° includes (1) ground -water the constant -head boundary at the downgrat of the aquifer, (2) ground -water discharge to lc 2. The of lniter "' ues uric fluxes Fat in udes f 1 lsend bosmdnrl ground wad ong aid gttifer and (4) 1 itcharee rl l sttnulaaans of premitting conditionsIn hypothetical sand -and - 6,925 6.928 24,748 1„019 6.929 6,929 3a9fib 3.966 7.551 3.5 1.914 11.913 3.128 11,915 le Analytical l and thlilleftcsi Simi on nt this t and Fractured Cry atalllne-Pluck Aquifer* Mitring +r gn el Sent Table 2. Steady-state ground -water budget for six numerical simulations of the effects of mining aggregate in hypothetical sand -arid -gravel aquifers (All values are io rcatdie meters per day: totals reflect sum of all minded individual components: nut cotepotedl Budget component Simulation I Stmutation 2 51esulallon 3 Simulation 4 Simulation 5 Simulation a Ground -water inflow from constant -head boundary al upgrr.tdient cud of aquifer Ground -water inflow front 8enerulyhead Lund aria along sides of aquifer River leakage to aquifer Precipitation recharge Total Ground -water outflow to constant -head boundary at downgradient end of uquifnr Ground -water discharge to river Ground-waterdischarge to actively dewatered pit Cumulative evaportise losses at pits Total ]merge to aquifer 6,937 6.937 25.532 4.043 4.043 7.684 2.019 6.921 6,933 3.956 3.975 4.652 4.639 16.541 3.608. 328 557 747 747 1.597 402 739 749 16..379 16.366 53354 0.029 11.944 12.244 Discharge from aquifer 6,505 6504 27,253 2,330 6.653 6.662 3.135 3,132 1,634 432 5.292 5.403 6.740 6.730 24,.500 3.260 680 16.380 16,366 53.387 6.030 II 945 12.745 Recharge -Discharge --1 Model simulations I. Pit in medium,s≥1etl.Iwntugrrt rtes, tt plc aquifer, _7. Pit in rrtedium•sited, hvttuu etavvus vertic lly anisonn pie aquifer 3, Pit in large. homogeneous. isotropic aquifer, 4. Pit in small, homogeneous, isotngnc aquifer. 5. Five pits lined with slurry walls in tuedium.sired. homogeneous, isotropic aquifer 4. Five watcr•filicd pits undergoing evaporative losses in medium -sired, homogeneous, isotropic aquifer. —33 l —1 --501 and (3) ground -water discharge to the pit under condi- tions of active mining. Under conditions of active mining, when the pit is dewatered, inflow from the upgradient end and the sides of the aquifer is slightly greater than under pre- mining conditions because drawdown caused by the pit increases the hydraulic gradient in the area between the pit and the upgradient end and sides of the aquifer. Recharge from precipitation is nearly unchanged between premining and active mining conditions. The slight difference in precipitation recharge between the two simulations likely is due to cells going dry during the rewetting process for unconfined conditions in the active mining simulation. River leakage to the aquifer is much greater under active mining conditions than under premising conditions because drawdown caused by the pit reverses the hydraulic gradient in the area between the pit and the river, which causes water to flow from the river to the aquifer. The largest compo- nent of discharge under active mining conditions is ground -water discharge to the pit. Outflow to the downgradient end of the aquifer under active mining conditions is somewhat less than under premising conditions because drawdown caused by the pit decreases the hydraulicgradient in the area between the pit and the down -gradient end of the aquifer. Ground -water discharge to the river under active mining conditions is less than under premining condi- tions because drawdown caused by the pit intercepts ground water that. under premining conditions, flows to the river. Simulation 2 -Pit Ina inedluim-sized, homogeneous aquifer with vertical anisotropy Simulation 2 shows the effect vertical anisot- ropy may have on steady-state drawdown near a dewa- tered pit in a medium-sized (about 2.500 m wide) alluvial valley. Simulation 2 is identical to simulation 1 except vertical hydraulic conductivity is uniformly set to a value equal to one -tenth the horizontal hydraulic conductivity. Simulation 2 represents a system in which lithalogic stratification of the sand - and -gravel aquifer has produced vertical anisotropy. SIMULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE le The simulated steady-state premining distribu- tion of hydraulic head in the anisotropic aquifer (fig. 12a) and steady-state drawdown near a dewatered pit in the anisotropic aquifer (fig. 126) are nearly iden- tical to those in the isotropic aquifer of simulation 1. The premining ground -water budget (table 1) for simulation 2 also is nearly identical to that of simula- tion I. The active mining ground -water budget (table 2) for simulation 2 differs only slightly from that EXPLANATION - 42— Lima of equal hydrauke head. In meters above arbitrary dun,n — Direction of river bow of simulation 1. River leakage to the aquifer, ground- water discharge to the river, and ground -water discharge to the pit under active mining conditions are slightly less in simulation 2 than in simulation 1 because the lower vertical hydraulic conductivity of simulation 2 reduces flow between the layers and, therefore, reduces exchange of water with the river and inflow to the pit bottom. 2.000 000 METERS 1 10.000 FEET Figure 12e. Numerical simulation 2 —Steady-state premining distribution of hydraulic head in a hypothet- ical, medium -stied sand -and -gravel aquifer under homogeneous and vertically anisotropic conditions. EXPLANATION — I,Q--- lane of eqini druxrdown. In motors — -- 3 Direction of river itac 0 0 1.000 IJ 5000 000 METERS 000 FEET Figure 12b. Numerical simulation 2 —Steady-state drawdown caused by a dewatered pa in a hypothet- ical, medium -sited sand -and -gravel aqulter under homogeneous and vertically anisotropic conditions. 20 Analytical and Numerical Simuletlen of the Stsedy-State Hydrologic Effects of Mining Aggregate in Hypothetical Send-and•Grevet end Fractured Crystalline -Rack Aquifers Simulation 3 -Pit In large, homogeneous, Isotropic aquifer Simulation 3 shows the potential hydrologic effects of dewatering a pit in a large alluvial valley. Simulation 3 is similar to simulation 1 except the allu- vial valley in which mining occurs is deeper and wider, and the hydraulic conductance of the general head boundaries and river are larger. The simulation represents a valley 7,000 m long and about 5,000 m wide. Layer 1 is 6 m thick with about 3 to 5 m of satu- rated thickness. Layer 2 is 16 m thick and is fully satu- rated. Thiel premining saturated thickness near the pit is about 20 m. The premising steady-state hydraulic gradient is about 0.003. which is typical of gradients in larger alluvial valleys in the Front Range area. Grid spacing and number of columns in the model are the same as in simulation 1. but 25 rows were added to accommodate the greater valley width. To simulate a greater amount of inflow to the larger valley, the hydraulic conductance of general- head boundaries along the valley sides in simulation 3 is approximately double that of simulation 1. Simi- larly, the hydraulic conductance of the riverbed is doubled to simulate a larger river with a greater capacity to exchange flow with the aquifer. The simulated steady-state pretnining distribu- tion of hydraulic head in the large aquifer is shown in figure t 3n, and steady-state drawdown near a dews- tend pit in the large aquifer is shown in figure 136. Area of influence in simulation 3 has a maximum extent (measured from pit center) of about 4,350 m. Area of influence in simulation 3 is larger and mote symmetrical than in simulation 1. Area of influence is larger in simulation 3 because the greater aquifer thickness and riverbed conductance allow snore ground water to flow to the pit, which must then be removed to maintain drawdown at the pit, As more of simulated aquifer EXPLANATION -- 42— Line of squat *Woe head, in meters above arbitrary datums -- Diruetrer of Over flown Figure 13a. Numerical simulation 3: -Steady-state premtning distribution of hydraulic head in a hypothet- ical. large sand -and -gravel aquifer under homogeneous and isotropic conditions. a } T 1.000 T t l T 5.000 2.000 3.000 METERS 11 10,000 FEET SIMULATION OF THE HYDROLOGIC EFFECTS OF WRING AGGREGATE EXPLANATION as Line at equal hy*au00 head, in meleis above wry dature - Dlr..at rivet kw 3.0000 METERS 5,000 10.000 FEET Figure 13d. Numerical simulation 3 -Steady-state drawdown caused by a dewatered pith a hypothetical, large sand -and -gravel aquifer under homogeneous and Isotropic conditions. water is removed, the effects of drawdown at the pit occur farther away. Area of influence in simulation 3 is more symmetrical than that in simulation 1 because aquifer boundaries are farther from the pit and, there- fore. have less effect on the shape of the area of influ- ence. The shape of the area of influence in simulation 3 is more like that of the infinite aquifer simulated using the analytical solution. Drawdown across the river in simulation 3 is greater than in simulation 1 because flow to the pit is greater and the bottom layer of the aquifer in simulation 3 is thicker, which allows the pit to draw more ground water from across the river. With the exception of ground -water discharge to the river under active mining conditions (table 2), flow for all ground -water budget components under pre - mining and active mining conditions (tables I and 2) in simulation 3 is larger than in simulation I because the aquifer in simulation 3 is larger and has higher conductances for the general -head boundaries and riverbed. Ground -water discharge to the aver under active mining conditions is less than that in simulation 1 because the larger area of influence in simulation 3 reduces the area where ground water can flow to the river. Simulation 4 -Pit in a small, homogeneous, isotropic aquifer Simulation 4 shows the potential hydrologic effects of dewatering a pit in a small alluvial valley. Simulation 4 is similar to simulation 1 except the width of the alluvial valley in which mining occurs is smaller, no -flow boundaries are used along the sides of the valley, and the conductance term of the riverbed is smaller. The simulation represents a valley 7,000 m long and about 1,200 m wide. Layer 1 is 4 m thick 22 Analytical and Numerical Simulation of the Steady -State Hydrologic Effects of Mining Aggregate to Hypothetical Sar d-Grevel and Fractured itiane•Ck Aqulfera with about t to 3 m of saturated thickness. Layer 2 is 2 m thick and is fully saturated. Total premining satu rated thickness near the pit is about 4 m. Because the aquifer in simulation 4 is shallow, the base of the pit occurs in model layer 2 rather than layer 1. The steady-state premising hydraulic gradient is similar to that of simulation 1. Grid spacing and number of columns in the model are the same as in simulation 1 but only 24 rows are needed to represent the smaller valley width. No -flow boundaries are used along the sides of the model to simulate an alluvial valley incised into bedrock with no ground -water inflow to the sides of the valley. Riverbed conductance is decreased by a factor of 2 to simulate a smaller capacity river flowing in the valley. The simulated steady-state premining distribu- tion of hydraulic head in the small aquifer is shown in figure 14u, and steady-state drawdown near a dews- tered pit in the small aquifer is shown in figure 14b. Area of influence in simulation 4 has a maximum extent (measured from pit center) of about 2.050 m. Area of influence in simulation 4 is smaller than that in simulation 1, but drawdown generally is greater because the sides of the aquifer are closer to the pit, and the no -flow boundaries do not contribute ground- water inflow to the aquifer as do the general -head boundaries in simulation L Drawdown across the river in simulation 4 is similar to that in simulation 1. Flow for all ground -water budget components in simulation 4 (tables I and 2), except river leakage to the aquifer under premining conditions (table 1), is smaller than in simulation 1 because the aquifer in simulation 4 is smaller and the riverbed has smaller hydraulic conductance than in simulation 1. River leakage to the aquifer under premining conditions in simulation 4 is larger than in simulation I because the no -flow boundaries along the sides of the aquifer in simulation 4 do not contribute flow to the aquifer. EXPLANATION 42— t(na of nqO MMtattlic had, in meters above afblVary dnsn. -�—} Dirsgion W river ree 2400 3,10 METERS tan 10,OcoFEET Figure 14a Numerical simulation 4 -Steady-state premining ci tab on cat hydraulic hold in a hypothetical, small sand -and -gravel aquifer under homogeneous and isotropb cordtions, oast ot simulatedaquifer EXPLANATION --� 01-- Lim cM equal drawda► n. i, motets Direction of fiver low 0 20 1,000 2,000 3,000 METERS r ( r ! I 11 s,00u trots FEET Plgure 146. Numerical simulation 4 —Steady-state drawdown caused by a dewatered pit at a hypo- thetical, small sand -and -gravel aquifer under homogeneous and isotropic conditions, tion SIMULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE 23 which causes the ground -water gradient between the sides of the aquifer and the river to be flatter and the water table to be lower than the river in places. Simulation 5 -Five pits lined with slurry rolls in a medium-sized, homogeneous, isotropic aquifer A slurry wall sometimes is installed around a pit to isolate it from ground water while mining continues or after mining ceases. Simulation 5 shows the poten- tial cumulative effect of five closely spaced pits lined with slurry walls in a medium-sized (about 2,500 m wide) alluvial valley. Simulation 5 is similar to simula- tion 1 except five medium-sized pits are simulated simultaneously. and the area of grid refinement near the pits was enlarged to encompass five pits rather than one. The revised model grid has 35 rows and 90 columns with a cell size of 50 nix 50 in near the pits and a cell size of 100 nix 100 m at a (distance of 500 m to 650 m front the pits. The five pits in simula- tion 5 are placed 100 m apart. Pits lined with slurry walls are simulated by using inactive cells at pit loca- tions, thereby simulating no -flow barriers at the edges of the pits where slurry walls would be present. Simu- lating the slurry walls as no -flow barriers maximizes the hydrologic effects of the pit on the aquifer. The simulated steady-state premining distribu- tion of hydraulic head in the aquifer in simulation 5 is the same as in simulation I (fig; 11a), and steady-state EXPLANATION Q Ft of wool drawdaw, in meats drawdown near the pits in simulation 5 is shown in figure 15. Drawdown near the pits is complex and ranges from about —0.5 m to 0.3 m. Drawdown is negative upgradient from the pits. which indicates ground water is mounding against the impermeable slurry walls. Drawdown is positive downgradient from the pits, which indicates the pits have a shadow effect on ground -water flow. The extent of upgradient mounding (defined by the limit of —0.l -m drawdown) is about 2,200 m wide, and the extent of down - gradient drawdown (defined by the limit of 0.1-m drawdown) is about 400 m wide. Ground -water levels across the river are not significantly affected by the pits in simulation 5. The preen ring ground -water budget (table l) of simulation 5 is nearly identical to that of simulation I. Slight differences between the two simulations likely are due to the larger area of grid refinement in simula- tion 5. Recharge to the aquifer from precipitation (table 2) under active mining conditions is slightly less than in simulation I because inactive cells used to simulate lined pits do not contribute flow to the aquifer. Recharge from all other ground -water budget components and discharge to all ground -water budget components are greater than in simulation l because active pit dewatering is not simulated. a,aaca DirecIkst of river flow Figure 15. Numerical simulation 5 -Steady-state drawdown caused by rate closely spared pits Med with slurry walls in a hypothetical, medutn•sized sand -and -gravel aquifer under homogeneous and isotropic conditions, neon t _ IV METERS 10,000 FEET 24 Analytical aid Numerical Simulation of the Steady -State Hydrologic Effects of Mining Aggregate Sm Hy cheat Sand -and -Gravel and Fractured Cryatalllne4teck Aquifers Simulation rive pits undergoing evaporative tosses In e medium-sized, homogeneous, isotropic aquifer Once mining is completed, aggregate pits may be refilled with water and used as water -storage reser- voirs or for environmental or recreational purposes. Simulation 6 shows the potential cumulative effect of evaporative losses from five pits after refilling with water in a medium-sized (about 2,500 ni wide) alluvial valley. Simulation 6 is the same as simulation 5 except cells at the pit locations are active (no slurry walls) and have horizontal and vertical hydraulic conductivity values 1,000 times greater than the surrounding aquifer material to simulate the open area of the pits. Using the MODFLOW-2000 Well package, evapora- tive losses are simulated as constant discharge from pit cells at a rate of 0.0034 m/d, which is approximately equal to average annual pan evaporation minus average annual precipitation for the Colorado Pied- mont part of the Front Range area (see "Hydrogeo- logic Settings"). The simulated steady-state premising distribu- tion of hydraulic head in the aquifer is the same as that of simulation I (fig. 1 la), and steady-state drawdown caused by evaporation from the pits is shown in figure 16. To separate the effects of pit evaporation from the hydraulic effects of open pits in the aquifer. drawdown is calculated relative to initial steady-state post -mining conditions, rather than premining condi- (ions. Drawdown near the pits is less than 0.1 mat all locations in simulation 6. For illustrative purposes, the limit of 0.05-tn drawdown is shown in figure 16, but this area of influence is not comparable to other simu- lations, which have areas of influence defined by the limit of 0.1-m drawdown. The premining ground -water budget (table 1) of simulation 6 is nearly identical to that of simulation 1. Slight differences between the two simulations likely are due to the larger area of grid refinement in simula- tion 6. Total evaporative loss from the pits is 680 m3/el (table 2). The hydrologic effects of pits in simulation 6 are small because evaporative discharge from refilled pits is small compared to the overall ground -water budget for the aquifer. Numerical <Sensitivity Analysis Composite scaled sensitivities were calculated. for each simulation input parameter by ming the Parameter Sensitivity with Observations mode (Hill and others. 2000) of MODFLOW-2000. Composite scaled sensitivities are dimensionless quantities that provide information about the importance of each input parameter to calculations of simulated equiva- lents (head or flow) at specific locations (observations) and indicate the amount of information that observa- tions contain for the estimation of a parameter (Hill, 1998). The actual value of sensitivity for each Omit of simulated oiler EXPLANATION - °,05 - Una d ocual dtawdowe fn tiltiOrS - ► D3ryntiw of Over II.a sues Figure 16. Numerical simulation 6 -Steady-state drawdown causes by fire closely spaced, water -flied pits undergoing evaporative losses in a hypothetical, medium-sized sand -and -gravel aquifer under homogeneous and isotropic condo orra, a UN sw'rrn5 10.400 FEET SIMULATION OF THE HYAFROLOGIC EFFECTS OF WING AGGREGATE 25 parameter is less meaningful than the relative magni- cede of the value compared to the sensitivities for other parameters. Parameters with high sensitivities affect. simulated equivalents more than parameters with low sensitivities, and high sensitivities indicate that avail- able observations provide much information on which parameters can be estimated. in this report, composite scaled sensitivities indicate the sensitivity of simulated head to variations in parameter values. The sensitivity of simulated flow to variations in parameter values was not calculated because changes in head (draw - down and area of influence) are the primary quantities of interest in the study. Sensitivities of simulated head were calculated for each parameter by using hypothetical observations distributed evenly throughout the numerical model domain. Twenty-six observations were used to calcu- late sensitivities in simulations 1. 2.5.. and 6 (medium- sized alluvial valley); 52 observations were used to calculate sensitivities in simulation 3 (large alluvial valley); and 20 observations were used to calculate sensitivities in simulation 4 (small alluvial valley). Observation locations are shown in figure 17, The use of hypothetical head observations does me affect simulation results. but the observations are necessary to generate composite scaled sensitivities using MODFLOW-2000. Composite scaled sensitivities depend on model construction and observation locations and are. there- fore, unique to each model. However. because obser- vations are distributed evenly throughout the hypothetical aquifers. composite scaled sensitivities describe the approximate overall sensitivity of simu- lated head to each parameter and may indicate which parameters are most critical to define at real sites having conditions similar to those of the hypothetical aquifers, Parameters with high sensitivities may be more important to accurately define for predictions of mining effects than paranreterrs with low sensitivities. Results of sensitivity analysis for simulation 1 are shown in figure 18. Results of sensitivity analyses for all sand -and -gravel aquifer simulations are shown in table 3. Results of the sensitivity analyses indicate simu- lated head was most sensitive to variations in hori- zontal hydraulic conductivity in every simulation except simulation b (five pits undergoing evaporative losses). in which simulated head was most sensitive to variations in the hydraulic conductance term of the SOWN EXPLANATION r: Hie! Wailmsban Figure 17. Location of hypothetical head observations used to eai€urate composite sealed sensitivities for numerical simulations of the hydrologic effects of mining aggregate in sand -and -gravel aquifers. general -head boundaries. In all simulations except simulation 6 and simulation 4 (no general -head bound- aries present). the sensitivity for general -head boundary conductance was second only to that for horizontal hydraulic conductivity and was similar in magnitude to that of horizotttal hydraulic conductivity. Similarly, the sensitivities for riverbed conductance and recharge were similar in magnitude to each other in all simulations except simulations 3 and 4, but the sensitivities were relatively small compared to those for horizontal hydraulic conductivity and general -head boundary conductance. Simulated head was relatively insensitive to vertical hydraulic conductivity in all simulations. For simulations of a real gravel pit or quarry, it would be important to include hydrologic observations of both hydraulic head and flow data for simulation 26 Analytical and Nuraertcal slrnudatlgn of the Stea tats Hydrologic Effects of Mining Aggregate to Hypothetical Send -and. Gravel and Fractured Cryalalnre-code Aquifers AL, VERTICAL HYDRAULIC HYDRAULIC 13Ou[doARY UCTAS E CONDUCTIVITY CONDUCTIVITY CONDUCTANCE figure 1$. Composite scaled sensitivities ter parameters in numerical simulation 1 (pit in a hypothetical. medium-sizedmedium-sizedsand-andipivel aquifer under" homogeneotasanat isotropic its. Table 3. Composite aid sans tiw(ies for paternelets used in six nurnerntal simulations of the elects Of mining aggregate in hypothelintd sandendvavel aquifers f, crt�r nq><r Sianuis#iann Paisrs Horizontal Vortical hydraulic hydraulic Recharge conductivity conductivity conduc Riv conductance 4 033 0,12 17,251 0.000070 Itt10i 11.1034 111141)16 010 042 11.1114131 11.1145 115 11,044 (1:(124` 0,29 11,26 0161 11,4151 0,10 b,in (PASO ►re rlilcwi, liontrigerwau, isorttliie rAllaf usar +xtraal� lonir>gcrtrxc variedly ,lam dolt tsnrsinpsitoo. Mu rk Aquifer, 4, t`Imappreolf, W.I. Aquifer, 5, l blurs a wllh gun tsts7G irl touiliuturAfAutt homogeneous., lrzlr at 11�ts"tai4esioriug napeorltive term in eviiiimUrtttlhon Ire SIMULATION OF THE HYDROLOGIC EFFECTS OF G AGGREGATE calibration (Hill, 19911). Hydraulic head data alone often do not provide enough information to break the inverse correlation between the hydraulic conductivity and recharge parameters and therefore obtain a unique solution to the ground -water flow equation (Hill, 1998). Streamflow or pit -discharge measurements provide a measure of ground -water discharge from an aquifer, and such flow measurements would be impor- tant to include when simulating actual gravel pits or quarries. Andermun and others (1996) present a detailed analysis of different types of hydrologic observations and their importance in ground -water flow simulations. Simulation of Quarries in Fractured Crystalline -Rock Aquifers Definitions of input parameters for simulations of aggregate mining in fractured crystalline -rock aqui- fers were based on data reported in the literature (see "Nydreageologic Settings"), Definitions of mining extents (area and depth) were based on mine permit information, site data, and quarry footprints shown on U.S. Geological Survey 1:50,000 County Maps. inter- mediate parameter values and boundary conditions were used in the simulations to represent average hydmgcolo€ic conditions and mining extents. Param- eter values and boundary conditions were then varied over a range of values and conditions typical for quar- ries in fractured crystalline -rock aquifers to determine the potential effects of mining over a wide range of conditlotts. Intermediate hydraulic conductivity was defined in the simulations as 0.01 rn/d, and interme- diate recharge was defined as 0.0001 mid, which is about ? percent of average annual precipitation for the Rocky Mountain part of the Colorado Front Range area. Intermediate quarry penetration of the water table was defined as 50 m, and intermediate quarry radius was defined as 200 m. Analytical Simulations and Sensitivities Two analytical solutions were used to simulate the effects of mining aggregate in a fractured crystal- line -rock aquifer. The analytical solution of Marinelli and Niccali (2000) was used to solve for the radius of influence (ri) and saturated thickness (h) above the base of a dewatered circular quarry in a homogeneous, isotropic, fractured crystalline -rock aquifer of infinite extent. Equation 7 was used to solve for the distance of influence (xi) and saturated thickness (h) above the base of a dewatered linear quarry in a homogeneous, isotropic, fractured crystalline -rock aquifer of infinite extent. Hetrizonutl hydraulic conductivity (Kr,), recharge (W), initial saturated thickness above the quarry base (h = /tu), and quarry radius (rp, circular quarry only) were varied independently over a range of values typical for quarries in fractured crystalline - rock aquifers in the Front Range area. By varying the parameters independently, the effects of each ,r. ram- eter on simulation results were evaluated, and sensitiv- ities for parameters were calculated. Because initial saturated thickness is measured relative to the quarry base, it,, also is equal to the depth to which the quarry penetrates the water table. The water level in the quarry was defined at the base of the quarry, Figures 19.22 show drawdown (hp — h) and radius of influence measured from the quarry wall (r, — rt,) caused by a dewatered circular quarry in a fractured crystalline -rock aquifer for different values of K1, (0.0001, 0.01, and 1 arid), W (0.000025, 0.0001, and 0.0004 mfd), /to (20, 50. and 80 m). and r (100, 200, and 400 m), Figures 23-25 show drawdrawn and distance of influence (xi) mused by a dewatered linear quarry in a fractured crystalline -rock aquifer for the same values of K5,W and /r,. Results indicate radius of influence from the wall of a dewatered circular quarry in a homogeneous, isotropic fractured crystal- line -rock aquifer of infinite extent was 411 m under intermediate coralitions (Ki, = 0.01 rn/d. W= 0.0001 mid, /aa = 50 m, r,,= 200 m). Distance of influence from the wall of a dewatered linear quarry under the same conditions was 500 m. Radius (or distance) of influence increased as .lK,,, It, and r+ (circular quarry only) increased and as Wde.sed. Equation 9 was used to calculate 1 -percent scaled sensitivities (see "Analytical Simulations and Sensitivities" under "Simulation of Pits in Sand -and - Gravel Aquifers") for each parameter used in the analytical solutions of Marinelli and Niccoli (2000) and equation 7 to determine the effect of each param- eter on simulation results under intermediate condi- tions. ns. Resulting sensitivities have units of meters and are the change in radius or distance of influence caused by a 1 -percent change in the parameter value. Results of analytical sensitivity analysis under intermediate conditions (1% =0.01 m/d, W = 0.0001 told, hi, = 50 m, ri, = 200 m) are shown in figure 26 for a circular quarry and in figure 27 for a linear quay. 28 Analytical and Nit Shrrulatton ot'the Steadytate Hydrologic Effects al &taring Aggregate in Hypothetic& San ired•Gravel and Fractured Cr stelltne-Rnctr Aquifers r =3.094 r 10 1,000 EXPLANATION fry Fitin.nral hydroulic a (vcovay m meets par gay Murry pranalrearan al 0* Maur We, irt meant rp Quarry maw. to maim rr ratdura of bananas irum warty Out in roam W Hathargat,,rnr 1p,160 FIXED PARAMETERS W. ta;OOW ho&tea fir= 20E DISTANCE FROM QUARRY WALL, IN METERS Figure i9. Drawdown relative to distance from a dewatvreet circular quarry in a fractured crystalline -rock agttfer for three values cif horizontal hydraulic conductivity, simulated by use of the Marinelli and Mccclt () analytical solution .220 rj. 411 r'r =715 10 loll LOCO A ION in Quarry el We, ml l rp Marty mats, s, to nialart rr Rafts 01trdloonooIran quarry ' 114111, m Marius W iSvMt0. 1 toult. prrday f Mt) FAI AMETERS h, . rl At -51] 000 DISTANCE FROM QUARRY WALL, IN METERS Figure 20. Drawdown relative to distance from a dewalered circular quarry in a fractured crystalline -rock aquifer for three values of recharge, simulated by use of the Marinelli and Nuccali ( 0) analytical solution ULATION OF THE HYDRA EFFECTS OF M MNG AGGREGATE in Cr 20 LLI 2, 2a' dA 45 O 4 50 75 00 = 00 EXPLANATION hydy. mEisra per day Na, Marry tweinigionit Inv wit tab*, NI maters rpQuarry rafts in nos • Heck. W Odium= tier, qty rill, in mere, W Remo, to meters is day RMIETERS DISTANCE FROM QUARRY WALL IN METERS Figure 21, O rawdown relative to distance from a dewalered circular quarry in a fractured Mine -rack aquifer for three values of quarry panekatku r of the water table, simulated by use of the Marinelli and War* (2000) analytical solution. EXPLANATION Roor tsruai hydraullc oanducilrh{y, in owlets fat day • pendrahonl$ the ivithil • MOM MOM • infltiantu r+ert+ rim y mat i+n W f , m melrrs ,* FIXED PARAMETERS Ks,.aat kr. 50 DISTANCE FROM QUARRY WALL, IN METERS figure 22. DrawatoVin relative to dim tram a metered circular quarry in a fractured crystalline -rock aquifer for three values of quarry radius, simulated by use of the Marinelli and Mott% (2000) analytical solution, 30 Analyttcanand Numerical tx"ttrtut®aon of the Steady-Elatey-Blete Hydrologic Maisel of Mmleg In Nitpe lst lSaru rwd Glravoi and Fractured Cryetaltlne-hawk Aquifers Figure 23. Dr of quarry paw �o- r� ru1pOCI EXPLANATION Cletto.rotta lettyiecanduchtahr, n¢ Chatty peneeelion el the water tea„ to ?ire r Vetenke at Mame trzam quer,+r,emews WV Recharge. in mien per day FIXED PARAMETERS Vv - 4-co01 h =so DISTANCE FROM QUARRY WALL, IN MEMRS theve to distance from a dewaterl linear quarry €n a fractured cr ys#rlline-rock aquifer for three values he water table, simulated by use of equation 7. T # __ .f. ...,d Li 3 .i.-¢ r k i j 1- e i 11 r EXPLANATION 1�Hareostal hydraulic sondi trrrry, in maims pet thry Ottitry Per totem of Vie voter lade, in rittin xr at due tarn warty wet tea W Recharge. inetersperrrjasr FIXED PARAMETERS Kh.0 01 htek 50 to oo DISTANCE FROM QUARRY WALL. IN METERS Figure 24, Drawdown restive to stance from a dewatered linear quarry in a fractured crystaflne-rock aquifer for three values of recharge. simulated by use of equation T. SIMULATIM OF THE NYDRot,OGIC EFFECTSOF M**rtG AGOREGATE O 1O .z la O 1O pA SO try _ n0 ® CE FROM QUARRY WALL IN METERS ,,.y EXPLANATION ��pn 1.1tanili nytimile coswi shiny, sin81on pat dav Gunny perallaSen of laa wilier table, in mikin Distance of inimainaIratt %mu," vont tio1 s, Flecicirce,IMF milk*par floc' F1000 PARA1,IE TEE E Kht001 W 0;0001 Figure 25.0raWd0Wn TeIatlua to t stanen trorn a dewatered linear quarry Ina fractured orystallirirodc aquifer ter dim values et quarry penetration of the War table. s+iinitlated bY use of equation 7. Results indiuite that radius or distance of influence O1% 111051mostsensitive- to changes in quarry penetration tyf the water table and least sensitive to changes in quarry radius (circular quarry only), Radius of influence wa. equally sensitise to changes in horizontal hydraulic conductivity and rechargeHowever. the }meters had opposite etfece. on simulation resells lase they rim inversely correlated in the analytical solution. Routiitrs (or distance) of influence increased as barn- zontat hydraulic conductivity increased and a recharge decreased. Numerical S mt~ilations MOD W_20Eltl (Marburg!' and others. 2(1(10' Was used to compute (I ) hydraulic heads in a hypes rhetieal fractured crystalline -rock aquifer tinder steady-statr premising conditions, (2) steady-state dr-awdown mused by a dew.alered quarry in the hat, lured crystalline -rock aquifer umber different hydro. geologic conditions, and (3) inflow to the quarry under different hydrogeologic conditions. In addition, the observation and sensitivity capabilities Will and Others, 200 0) of MOh) W 2(Jtl() were used to compute sensitivities for simulation input parameters, Although tMMOCJFt OW --2011) is designed to simulate ground -water flow in a porous mc'litim, such as a sand-and-gravel'aquifer. the code also was used in this study to simulate the elects of mining in a fractured crystalline -rock aquifer bruise it is well documented. well supported. and has been successfully applied to other fractured -rock seeing s (Tietleinan and others, 1997; Daniel and cmrtters, 1997; bIng and. others, 1982). Because simulations art of hypothetical aqui. firs. model calibration was not necessary. However. generalized aquifer data futt'r real itites were used to guide development of simulatyreminir►g conditions. rls,. Six numerical simulations of the hydrologic effects of mining aggregate itr hypothetical fractured crystalline rock aquifers are presented as follows: Simulation 7 —The hydrologic effects of aclewa r1<red quarry in alhomogeneous and isotropic fractured elystalline-tock; aquifer are simillata Comparison tit simulation 7 to analytical simulation results shows the effects of botmdary conditions, Simulation 8 —The hydrologic effects of a &wa- tered quarry in a homogeneous but hcnriionrally anise - tropic. Incurred crystalline -rock aquifer are simulated. 32 Analytical and rlunrericei seliuiatron of the sme smeie Ovoidal& Meets of Mining Aggregate in Hypothetical Send-end•Girevet end Fractured CryeAalll ne ock Aquifers HORIZONTAL C:ONQUOTAriT IK RECHARSe E u�. MARRY PENETRATION THE WATER 11811 (1O MARRY RADIUS PARAMETER *Swarm. indicalA durog911 ►adius oi Whams, kr(mei Figure 26, On , fed seersttiriflas for parameters in the analytical solution of Mari neat and Nicco4 (20 4, dated fors circular quarry in a tried crystallinalocir aquifer under Fnlemrredlate concfaions 04n= O.0i #d. ktr 0,0001 rrv'd, Nt . m, rp = 200 MY OAAg.ndisloAceoI nil , k� 9i►I}r rV.InI dump t Figure 27. Onopercent scaled sensitivities tar parameters er equation 7 calculated for a linear quarry in a fractured crystalline -rock aquifer under intettriediate conditions (Kh= 0.01 mid, W.,- 0.0001 , ha = 50 rn), SIMULATION OF THE tiYSIHOLCrGIC EFFECTS OF MIMNG AGGREGATE Comparison of simulation Ft to simulation 7 shows the effects of horizontal anisotropy. Simulation 9 —The hydrologic effects ofa dewa- tered quarry in a fractured crystalline -rock aquifer with three hydraulic conductivity zones are simulated. Comparison of simulation 9 to simulation 7 shows the effects of lateral variations of hydraulic conductivity. Simulation 10 —The hydrologic effects of a dewatered quarry in a fractured crystalline -rock aquifer with ground -water flow in deep, low -perme- ability fractures are simulated. Comparison of simula- tion 10 to simulation 7 shows the effects of adding a layer of low hydraulic conductivity to the bottom of the model. Simulation I I The hydrologic effects of a dewatered quarry intersected by a hydraulically conductive fault zone in a homogeneous and isotropic fractured crystalline -rock aquifer are simulated. Comparison of simulation I 1 to simulation 7 shows the effects of a fault zone that provides a conduit for ground -water flow. Simulation 12 —The hydrologic effects of a dewatered quarry intersected by a low -conductivity fault zone in a homogeneous and isotropic fractured crystalline -rock aquifer are simulated. Comparison of simulation 12 to simulation 7 shows the effects of a fault zone that forms a harrier to ground -water flow. Si 742uarry to °geneous, isotropic aquifer Simulation 7 shows the potential hydrologic effects of a dewatered quarry in a homogeneous and isotropic fractured crystalline -rock aquifer. The simu- lation the intermediate value of horizontal hydraulic conductivity, recharge, quarry depth, and quarry width from the analytical simulations to facili- tate comparison between the simulations. Modal design A fractured crystalline -rock aquifer is wpte- sented using one layer with a thickness of 100 m and a horizontal hydraulic conductivity of 0.01 mid (fig. 28). Vertical hydraulic conductivity is not considenxi because the model has only one layer. Saturated thick- ness in the vicinity of the quarry ranges from about 75 to 100 m. The aquifer is simulated as convertible, which allows hydraulic head to be computed for either confined or unconfined conditions. The model grid has 34 rows and 31 columns with a cell size of 100 m x 100 m near the pit and 200 m x 200 mat a distance 1.000 m from the quarry (fig. 29). The model domain is 4,500 m by 5.200 m. The hydraulic gradient is about 0.1 in the vicinity of the quarry. Boundary condttlons The left side of the aquifer (fig. 29) is simulated as a no -flow boundary to represent a ground -water divide coincident with hilltops along a major topo- graphic high. top and bottom edges of the aquifer (map -view) also are simulated as no -flow boundaries and are assumed far enough from the quarry that their influence on simulation results was negligible. The right side of the aquifer is simulate as a constant -heed boundary to represent a large stream flowing alb the bottom of a prominent valley. The aquifer base is simulated as a no -flow boundary at a depth 100 m below land surface to represent the depth below which fracture permeability is assutited negligible. A speci- fied -flux boundary with a value of 0.0001 mid is used to simulate areal recharge from precipitation. Valleys in the model domain are simulated as drains by using the Drain package of MODF OW- 2000. The hydraulic conductance of drains is defined based on a valley 30-m wide with a 3-m thick layer of valley -bottom sediments having a hydraulic conduc- tivity of 1 told. The use of drains in the mountain valleys was important to obtaining a realistic steady- state distribution of hydraulic head in the aquifer under premising conditions. The quarry is simulated as a 400 m wide square with truncated corners at the upgradient wall and a maximum water -table penetration of 50 m. The quarry also is simulated as a drain by using the Drain package of MODFLOW-2000 becauground- water inflow to quarries in fractured crystalline -rock aquifers commonly is slow enough that active dewa- tering measures are not needed (Knepper, 2002) and because the quarries commonly are cut into steep hill- sides where the water table may not be penetrated by all parts of the quarry. Results and comparison to analytical simulation The simulated steady-state prom ning distribu- tion of hydraulic head in the aquifer is shows in figure 30u, and steady-state drawdown near a dewa- tered quarry in the aquifer is shown in figure 30h. Steady-state drawdown computed using the analytical solution of Marinelli and Niccoli (2000) fora dewa- tered quarry in a homogeneous, isotropic fractured 34 Analytical and Numerical Simulation of die Staady-Scats Hydrologic Effects of Mining Aggregate in Hypothetical and Fluttered Crysfentnsflack Aquifers tofi10 bout , Cr 1 IAyer (KM rims ;SwW b;;NW EXPLANATION :phi f* H lvonlM florist t tontatifitmtv fydrawaht tmdtctevsco +'t*tftollttsj tit* irran aflutter Ui vaeilcsbirrruIited as drums Kris'= Phitgrathe canductatto ca ra:k m Ikm 1mm Altair 4o quarry sirnr tialed as drew i ConsMMottbeao tyounclary Figure 28. Conceptual dragrarri for numerical simulation 7 (quarry in a hypothetical fractured crystalline -rock aquifer under T homogeneous and Isotropic condltmo ). crystalline -rock aquifer or infinite extent is shown in figure 30e. Result of the analytical simulation were coMplited using the same values of horizontal hydraulic conductivity, recharge, pit penetration or the eater table, and pit radius aN the numerical simulation. Lines of equal dr awtlown computed by the analytical simulation occur as concentric circles centered around the quarry. and area of influence computed by the analytical simulation (defined by limit or 1-m dr-awdo nl has a radius of 513 im filealiUted from the quarry center. Lines of equal draw - down computed by the numerical simulation are asym- metrical Ilecausc of boundary effects, Area of influence (defined by limit of l e n drawr.lown ) computed by, the numerical simulation has a maNituu n extent of about 1,300 r, treasured from the quarry center, Area of influence in the numerical simulation i*. larger than in the analytical simulation because saturr r-dted thickness WO the gnarl) In the numerical simulation is greater, which increases aquifer rmn%r tni%sivity, Area of influence increases as aquifer trans- missivity increasys. Drawdown in the numerical simulation is centered around the upgr a d inu wail of the quarry because the quaint is excavated into a water table with a steep gialient. Because the base of the simulated gnarly is level. the upgradient wail: of the quaity penetrates the water table tee a greater degree than the dnwirradient wail. Valleys simulated as drains in the numerical simulation affect the shape of area olw influence, hut urea of influence emends across the valley nearest the quarry. The complete ground -water budget (or pre - mining conditions In simulation 7 is shown in table 4. and the complete ground -water budget for the effects of the dewatered quarry in simulation 7 is shown in table 5. The ground -water budgets give an accounting of recharge to the aquifer and discharge from the aqui lei. Values given in the tables indicate total Volur mirk (Mixes for all celk of a given type* Recharge to rlre aquifer includes groundewater inflow from the SIMULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE 35 15 30 1 5 10 t5 :5 Ia. mitt I. 101Pw 1.11111111111.11111111111 1,11111111111111 ��M= �IIIWI 1.1 NI1101111111111 ul rpenienneranin= I =I gama as ma' gra= - ACC ma Isms—Lsraa.teamnnaaaaspssiv•Nstsaagl:::ir � MI IIIIIII wit MESON I111111111111111111 RI ME • k! mroqu INN 111 J E a. METERS r ji 5.000 EXPLANATION ACWp cell Constantmeadcall Drain cep itlatliVO COI $0 COG FEEl Otiarry Figure 29e Finiteedifference gild and boundary conditions for numerical simulation 7 (quarry to a hypothetical fractured crystalline -rock aquifer under homogeneous and isotropic conditions), =onsantwhead boundary ad distributed recharge from precipitation. Disehat a from the aquifer includes ( I ,) ground -water outflow to the constant head boundary, (2) ground=water discharge to valleys simu- lated as drains, and (3) ground -water discharge to the quarry under conditions of active mining. Under premining conditions. nearly all recharge is from precipitation. Very lithe charge is contributed by the constant -head boundary because the boundary occurs along the downgradient edge of the model. Most discharge item the aquifer under premining conditions occurs to valleys simulated as drilla but discharge to the constant -head boundary also is signil= leant. Under conditions of active mining, when the quarry is dewacereds recharge is nearly identical to premining conditions, but discharge to valleys and the constant -hand i -fuming.); is less because the quarry intercepts ground water that. under premining c+c�ndi= dolls, flows to the valleys and the eonstantehead boundary. Discharge to the quarry in simulation 7 is much Iewc than discharge to the pit in simulation I because the hydraulic conductivity of the fractured cr stallinc_ oek aquifer is much less than that of the sand-andegras'el aquifer 36 Analytical and Numerical Simulation or the Steady -State Hydrologic Effects at Mining Aggregate in Hypothetical Sandand-Gravel and Fractured Crystalline -Rock Aquifers 1,030 I 10.000 FEET EXPLANATION Una of woad hydradk head. in meters above eibleary shawl ' ..t 4.lay Eftliated aS drain Figure 30a Numerical simulation 7 —Steady-state premining distribution of hydraulic head in a hypothetical fractured crystalline -rock aquifer under homogeneous and isotropic conditions. SIMULATION OPINE HYDROLOGIC EFFECTS OF MINING AGGREGATE 37 Knit 01 simuteted aqutler o 1,000 it 0 so00 3,000 METERS 10.000 FEET EXPLANATION - 10 - Line of equal hydraulic head. in molars aaao art,itrery datum Va0ey simulated as drain a Figure Mix Numerical simulation 7 --Steady-state drawdown caused by a dewatered quarry in a hypo- thetical fractured crystalline -rock aquifer under homogeneous and isotropic conditions. 1.000 t I 0 5.000 2,000 I EXPLANATION --- 10 - Lino of equal hydruuft toad. in molars above artbtrary 0010m 3,000 METERS 1 10.000 FEET 0uarry Figure 30c. Steady-state drawdown caused by a dewatered quarry in a homoge- neous, isotropic, fractured crystalline -ruck aquifer of infinite extent, simulated by use of the Marinelli and Niccoli (2000) analytical solution. 35 Analytical and Numerical Simulation of the Steatiratide Hydrologic Effects of Mining Aggisgaite in Hypothetical Sand -and - Gravel and Fractured Crystalline -Rock Aquifers Simulation 8 -Quarry In a homogeneous aquifer with horizontal anisotropy Simulation 8 shows the effects horizontal anisotropy may have on steady-state drawdown near a quarry, Simulation 8 is identical to simulation 7 except hydraulic conductivity along columns in the model is assigned a value three times greater than the hydraulic conductivity along rows. Hydraulic conductivity along rows is 0.01 mid as in simulation 7. Simulation 8 represents a system in which fracture permeability in one horizontal coordinate direction is greater than that in another coordinate direction. The simulated steady -slate premining distribu- tion of hydraulic head in the aquifer is shown in figure 31a, and steady-state drawdown near a dewa- tered quarry in the anisotropic aquifer is shown in figure 31b. Premining hydraulic head in simulation 8 generally is slightly lower than in simulation 7 because the increased hydraulic conductivity along columns in simulation 8 increases discharge to valleys, which lowers the water table. The water table of simulation 8 Limit of simulated etbailer 1,000 2.000 I 1 3,000 METERS 5.000 10.0D0 FEET EXPLANATION - Ct -- I aGna of aqua! hydraulic hid, in metes above erbhary dotal � J vaney uenuland as dray Figure 3).a• Numerical sirnadati0n 8 -Steady-state premising distribution of hydraulic head in a hypothetical fractured crystalline -rock aqulter under homogeneous and horizontally anisotropic conditions. SIMULATION OF THE HYDROLOGIC EFFECTS OF MINIM AGGREGATE 3,000 METERS 10;000 FEET EXPLANATION -- 1p Line at equal hydraulic bead in rnaiers above arbitraryr datum Valley simulated as drain Figure 31 b. Numerical simulation 8 -Steady-state drawciowrt caused by a dewatered quarry ka hypothetical fmctured crystalline -rock aquifer under homogeneous and horizontally anlsotropic conditions, is mostly below the elevation of the valley nearest the quarry; consequently, the valley has less effect on the quarry area of influence than in simulation 7. Area of influence in simulation 8 has a maximum extent (measured front the quarry center) of about 1,600 m and is elongated in the direction of greater hydraulic conductivity along columns because area of influence increases with increasing hydraulic conductivity, Area. of influence along rows is similar to that of simulation 7 because hydraulic conductivity along rows is the same for both simulations. Ground -water inflow from the constant -head boundary is larger and outflow to the constant -head boundary is smaller under premining conditions (table 4) in simulation 8 than in simulation 7 because the lower water table of simulation 8 causes the 40 Analytical and Numerical !simulation of the StsadtState Hydrologic Effects of kilning Aggregate In Hypothetical Sand ed Gfavet and Fractured Crystatgne-ffiock Aquifers hydraulic gradient between the aquifer and boundary to be less. Discharge to valleys simulated as drains under premining conditions in simulation 8 is larger than in simulation 7 because the greater hydraulic conductivity along columns increases ground -water flow to the valleys. The ground -water budget for simu- lation 8 under active mining conditions (table 5) is similar to that for premining conditions except the quarry intercepts some ground water that, under premining conditions, flows to valleys. Ground -water discharge to the quarry is greater in simulation 8 than in simulation 7 because the greater hydraulic conduc- tivity along columns increases ground -water flow to the quarry. Simulation a -Quarry in an aquifer with lateral variations of hydraulic conductivity Simulation 9 shows the effects lateral variations of hydraulic conductivity may have on steady-state drawdown near a dewatered quarry. Simulation 9 is the same as simulation 7 except the model domain is divided into three zones with each having a different horizontal hydraulic conductivity (fig. 32a). Hilltops are assigned a horizontal hydraulic conductivity value of 0.1105 in/d to represent relatively unweathered crys- talline rock with fewer fractures at the core of moun- tains. Major valleys are assigned a horizontal hydraulic conductivity value of 0,05 mild to ,represent areas where streams have incised into more highly fractured rock. The area between hilltops and major valleys is assigned a horizontal hydraulic conductivity value of 0.01 mid as in simulation 7. Hydraulic conductivity is homogeneous and isotropic within each zone. The simulated steady-state premining distribu- lion of hydraulic head in the aquifer is shown in figure 32a. and steady-state drawdown near a dewa- tered quarry in the aquifer is shown in figure 32b. The lower horizontal hydraulic conductivity of hilltops in simulation 9 causes hydraulic head to be higher and the water table to be steeper beneath hilltops than in simulation 7. Similarly, higher horizontal hydraulic conductivity along major valleys in simulation 9 causes hydraulic head to be lower and the water table to be flatter beneath major valleys than in simulation 7. Area of influence in simulation 9 has a maximum Table 4. Steady-state ground -water budget for sip numerical simulations of premining conditions in hypo crystalline -rock aquifers {All wanes are in cubic metes per may- torah reflect sum of all rounded individcaal componemsl heal fractured Budget component Simulation 7 Simulation 8 simulation 9 Simulation 10 Simulation 11 SImulation 12 Ground•watcr inflow from constant head boundary Precipitation recharge Total Ground -water outflow to constant- head boundary Ground -water discharge to valleys simulated as drains Total. Recharge — Discharge Model simulation; 7. Homogencomns isotropic aquifer. 8. ltottneneous, horiaontally onisutmplc aquifer. 9. Aquifer with lateral variations cT hydomlir conductivity. 10. Aquifer with ground -water flans' in deep. low -permeability fractures 11, .Aquifer with n fault zone that acs as a conduit for ptownd•water flow.. 12. Aquifer with a fault zone that acts as a barrier to ground -water flow 4 Recharge too aquifer 14 39 4 4 4 2.151 2.151 2,151 2,151 2.151 2.151 2.155 2.165 2.190 2.155 Discharge from aquifer 80 438 890 1.575 1.726 1.299 1,555 2.155 ?.155 20 551 1.534 1.603 2.155 2,189 55 2.154 2,154 SIMULATION OF THE HYDROLOGIC EFFECTS OF Id11MNG AGGREGATE 41 Table S. Steady-state ground -water budget for six numerical simulations of the effects of mining aggregate in hypothetical fractured crystalline -rods aquifers (All values are in cubic meter, per day; totals reflect sum of all rounded individual catnponcnts l Budget component Simulation 7 Stmeletlert 6u $imuletion 9 Simulation 10 Simulation 11 Simulation 12 Ground -water inflow from constant - head boundary Precipitation recharge Total Ground -water outflow to constant head boundary Ground-watershscharge to valleys simulated as drains Ground -water discharge to quarry Taal Recharge -Discharge Model simulations 4 Recharge to aquifer 14 40 2,151 2,151 4 4 4 2.151 2,151 2.151 2.151 2,155 2,165 2,191 2.135 2,155 2,155 Discharge from aquifer 438 1142 1,504 1,587 1,258 109 139 91 558 550 529 1,483 1,456 1,531 115 149 94 2153 2,161 2 2,191 2,156 2,155 2.154 —1 0 7. Quarry in a homogenous. isotropic aquifer. 8. Quarry in a homogeneous, horizontally nnisotroprc aquifer. 9, Quarry in an aquifer with lateral variations of hydraulic conductivity,. It. Quarry in an aquifer with ground -water flow in deep. to wpern+eahility fractures. 11. Quarry intersected by a faailt rune that acts as a conduit for flow. 12. Quarry intersected by a fault acne that acts as a barrier to ground -water flow. extent (measured from quarry center) of about 1,100 m. Area of influence in simulation 9 is smaller than in simulation 7 because the lower horizontal hydraulic conductivity of hilltops reduces the area of influence upgradient from the quarry, and the higher horizontal hydraulic conductivity of the major valley along the right side of the model domain increases the effects of the constant -head boundary, thereby reducing area of influence downgrudient from the quarry. Ground -water inflow from the constant -head boundary and outflow to the constant -head boundary under premining conditions (table 4) in simulation 9 is greater than in simulation 7 because the higher hori- zontal hydraulic conductivity of the major valley along the constant -head boundary facilitates ground -water flow between the boundary and the aquifer. Discharge to valleys underpretnining conditions in simulation 9 is less than in simulation 7 because the water table in the vicinity of valleys simulated as drains in simula- tion 9 is lower than in simulation 7, The ground -water budget for simulation 9 under active mining conditions (table 5) is similar to that for premining conditions except the quarry intercepts some ground water that, under premising conditions, flows to valleys and the constant -head boundary. Ground -water discharge to the quarry in simulation 9 is less than in simulation 7 because saturated thickness near the quarry in simula- tion 9 is less and aquifer transmissivity is smaller. Simulation 10 -,fumy in en aquifer with ground -water flow in deep, low -permeability fractures Simulation 10 shows the effects adding a model layer to simulate ground -water flow in deep, low - permeability fractures may have on steady-state draw - down near a dewatered quarry. Simulation 10 is similar to simulation 7 except a second layer is added. As in simulation 7, the top layer (layer 1) is 100 m thick with a horizontal hydraulic conductivity of 0.01 mid. The new layer (layer 2) underlies layer 1 and is 50 m thick with a horizontal hydraulic conduc- 42 Analytical and Numerical Simulation of the Sfeedy-State Hydrologic Effects of t lning Aggregate to hypothetical SandandOravel and Fractured Crystalline -Rook Agrees ei _. C+ 1 meter per day ,P'E =Gcc'i ineler Ozer day 0 t,cou 3,0(X) METERS --- 430 r,4,463/4 shit 5.000 EXPLANATION i_,r a Cif equal hydraulic head, In r'eli'cs above arbitrary daktri Valley sitstitilaled as drat, E 1 10.000 FEET fr, Honrontal Ihy uJc cOridi ClMly $ f i 0.1 r+nStn per day Figure 32a Numerical simulation 9 -Steady-state premtn ng distribution of hydraulic head in a hypothetical fractured crystalline -rock aquifer with lateral variations of hydraulic conductivity tip°ity of 0,001 mid. Vertical hydraulic conductivity is set equal to horizontal hydraulic conductivity in each layer. The simulated steady -:Mate prerninmg distribu- tion of hydraulic head in the aquifer is; shown in figure 33a, and steady -slate drawdown near a dewa- tered .quarry in the aquifer is shown in figure 33h. Area of influence in simulation ID has a ntaximum extent (measured from quarry center) of about 1,300 tn, which is the same us in simulation 7. However, area of influence across the valley nearest the gwirry is larger in simulation 10 than in simulation I because the aquifer represented by two layers in simulation 10 is thicker and has higher trtuismissivity. Because horizontal and vertical hydraulic conductivity in later 2 are an order of magnitude lower than in layer I , the additional thickness created by adding layer 2 has 0111) a small effect on transmissivity and, conse- quently, on area of influence. Recharge to the aquifer under premining t*ondi Lions (table 4) in simulation 10 k identical to that in SIMULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE 43 s of nby ipatiaoupponstispo pains au pue ia4eJ9-pure-pees jingaq sodAH 111 oieSai66v buouivj en 51300 3 Of6ojoipAH ainstApessis 0) )a twl1einulj$1e3paumw putt tenpiiteuv tev AnAtionpuop apineapkg #O suo1ejJBA mem 411M iapnbevashauffiepoto peal jeagaattndALI e up Sena paaalemap e Aq pesne3 uMop e4p atelssApealses uoszejnums RousuinN 'fee einemm ►334 000 01 f setae,' mot App Jad .rw D uj*u ' t! pgitm *.sit'i 4907s ribbitmese % POW III ', W00401540 it0103, p clog NollVNV1dx] 000'5 I I _ netrt p rvatig ip own lRSril aq (11 AI! 4%.!ssitutUUJ1 uaj trlht! sasnt*a tptittA iairaJc 9 (1I tit- TTu(nulls 18 Luutnh) any ,ii'?U swatiynit(I paietny% zip astnItxitl / tiottp1fttit' ;q urv1 sapiati Si 01 unilrtntuts U! kr 11 11 mtga!p1aw ►tpctistU9. 44(snpunoq peat-1uti14iUILl alp pun s;taljmi c3) ,%%0U "wog -pina tIumulaid Japuii van Jam* purrniI awns sukn �ascu iminh. ay1 idaaxa suronnpupa fluiuit.ilari Jai tnm O1 JR trigs ci (c ?NM) suoiupuoa ttjtuittl a.��lais a h�Ut1 LI OA Aen i ad misui I n -Alit Aep Jed Ji1w toot = qv 01 uc_t!Iu(n►tiN sal 1�a pnq ifIrt%-ptifittla at(il. DO i untie' -ntt�r IJl lamas Apiti1ns 43i awl ia11'm at1) asntiagq t 11031 -ttlnttr!s IA! unto .imintus s! 01 uo1.lUjnttt!s l.II ut,i!)!ptto;) ifuswuiaid i3ptsu sAolirtt 0) affitNasKri •01 ur)ue(ntu!% ►l! Jainala tit alut*puntaq pearl-iunpaac a an U11uaarlpr. %sac, -sp!tp paitunuts asnexxi is t►owt(ftutg ti! unit ( t uti!1UE -nttlls u1 suomposti iuntta a d Japurt to .lnj ,{j1t;1fls• s! amusing PZ1tl-1uui%URbl ?t(101 O Jnynsm •L tltl!Ir$rsutts 5 ms is.000 FfEr EXPLANATION - Lim it equal brimis hoot in +airs abwe arbitrary sr tort o•--",„..1 Valleysimulated as coin Figure 33a. Numerical simulation 10 -Steady-state premising distri- bution of hydraulic head in a hypothetical fractured crystalline -rock aquifer with groundwater flow in deep, low -permeability fractures. Simulation 11 -Quarry intersected by a hydraulically conductive fault zone Simulation l 1 shows the effects a hydraulically conductive fault or fault zone may have on steady-state drawdown around a dewatered quarry. Simulation l t is similar to simulation 7 except a fault zone having a horizontal hydraulic conductivity or 0.1 told intersects the quarty< Recharge to the aquifer under premising condo Bons (table 4) in simulation I I is identical to that in simulation 7> [ ihte to the constant -head boundary is slightly larger under pretnining conditions in simu- lation II than in simulation 7 because the hydrauli- cally conductive fault zone increases gerund -water flow to the boundary. Discharge to valleys under premining conditions in simulation I 1 is smaller than in simulation 7 because the water table is slightly lower beneath the valley nearest the fault zone in simulation I I . The ground -water budget for simulation I I under active mining conditions (table 5) is similar SlMULA1iOlil OF THE HYDROLOGIC EFFE O NG AGGREGATE to that for premining conditions except the quarry intercepts some ground water that, under premining conditions, flows to valleys and the constant -head boundary. Ground -water discharge to the quarry in simulation I I is greater than in simulation 7 because the hydraulically conductive fault zone increases ground -water flow to the quarry: The simulated steady-state premining distribution of hydraulic head in the aquifer is shown in figure 34a, and steady-state drawdown near a &watered quarry intersected by a hydraulically conductive fault zone is shown in figure 34b. Premining hydraulic head in simuiaticm I I is slightly lower along and upgradient of the fault zone compared to simulation 7 because the fault zone feed - tats ground- water flow along the fault. Area ofinflu erne in simulation I I extends along the fault zone and has a maximum extent (measured from quarry center) of about 1,600 rri. Area of influence in simulation 11 is larger than in simulation 7 because'area €►f influence increases as hydraulic conductivity increases, sees fa a EXPLANATION Taal *memo, W.W.I suletad as drain Figure 33b. Numerical simulation 10 -Steady-state drawdown caused by a dewatered quarry in a hypothetical fractured crystalline -rock aquifer with ground -water low in deep, low -permeability fractures. 46 Anaiytical erred Numerical Simulation of the Steady State Hydrologic Effects of Mining Agg end Fractured Crystalline -Rock Aquifers r4A$t KL JOI TWINS pun ou sum pun (I ing inmPAI 101 C u ptu3'- oI a pap p suntan ono' 11: h e t ti quit r Wider preminin cued fibre (tab4) in ss'mt ls�ii 2 is idenli t tea tt in mulntinn 7Disci's 1 -head 1s 8 y snl u�r rtinun i tins inzrrulnti12 I in sirultsn 7 tuw ndtr ivi f utt./ di es d- er 1ltxv to tie n . Ii;�ae'tu v�11 fir` pt n in t r liti In t tl12 is sirnttlatit n tt t1 grater table is t1 llae vallo nest tl t t tiu �u ti rater budget f rr srm lnllitan t dt< mining n itec n .{table is.sin la ttti nr that, under pretntntng co ititm Ili 11ey the+nt= rdisci)arg to th ray in sin n ,nn s %s l aura 7 tt the 1 iiity ul 10.000 FEET EXPLANATION S30- Lfreol aquae hiti.1.14G head. is mom above arb+bsty datum Wileysimutated drain Figura 35a, Numerical sire n 12—Steadrstalaprecnining diatribution of trytkaultc head al a hypothetical fractured prysta[1ne-roc k aquifer with a low -can ductivity faun zone. SIMULATION OF THE HYDROLOGIC EFFECTS OF MINING AGGREGATE 1,o r EXPLANATION 0 -�-- Una e1 ell**auk Wet ere Melee 0:43.1a0130efAuwre einelatad fie drain a Rome SEb; Numerical simulation 12 -Steady-state drawdown caused watered quarry intersected by a l# conductivity. fault ions in a hypothetical fractured crystalsaquifer. Amory** and Nurtwrical 136nOlatiort of ltre lo Hydrula0 Wells of Wing Agg cn HypoiNtical' Onwe! Fractured. Crystakhre-Rock Aquiftra Numerical Sensitivity Analysis Composite scaled sensitivities (see "Numerical Sensitivity Analysis" under "Simulation of Pits in Sand -and -Gravel Aquifers") were calculated for each model parameter by using the Parameter Sensitivity with Observations mode (Hill and others, 2000) of MODFLOW 2000. Sensitivities were calculated for each parameter by using 27 hypothetical head observa- tions distributed evenly throughout the numerical model domain as shown in figure 36. Sensitivity analysis results for simulation 7 are shown in figure 37, and sensitivity analysis results for all simulations in fractured crystalline rock are shown in table 6. Sensitivity analyses results indicate simulated hydraulic head was most sensitive to recharge and horizontal hydraulic conductivity in every simulation. In simulations 7 and 8, the sensitivities for recharge and horizontal hydraulic conductivity were almost equal. However, in simulations 9, 10, 11, and 12, more than one horizontal hydraulic -conductivity parameter was used, and the sensitivity for recharge was greater than that for any individual horizontal hydraulic- conductivity parameter. In simulation 9 (quarry in an aquifer with lateral variations of hydraulic conduc- tivity), sensitivity for horizontal hydraulic conduc- tivity was greatest for hilltops (low hydraulic conductivity) and least for valleys (high hydraulic conductivity), In simulation 10 (quarry in an aquifer represented by two model layers, one of which simu- lates ground -water flow in deep, low -permeability fractures), the sensitivity for horizontal hydraulic conductivity in layer 2 was much less than that in layer 1. In simulations 11 and 12 (quarry intersected EXPLANATION 0 Head obsermatiOn Vatay simulated as dr n Figure 36. Location of hypothetical head observations used to date composite scaled sensitivities for numerical simulations of the hydrologic effects of mining aggregate in fractured crystallirerocs aquifers. SIMULATION OF THE mvpRoLoGIC EFFECTS OF WW1 AGGREGATE et 40 5 in 5.015 MAW N Q CONCILICIMICE COWL) IVY ICIOAPIR PARAMETER Fire 37, Cornposite Wiled sensitivities for parameters in numerical simulation 7 (quarry in a fractured c'ystatiirte-rock aquifer under homogeneous and isotropic conditions), Table 6. Co site scaled sersativlties for parameters Used in six nUmencat simulations ul the effects of miring agwegata in hypothetical fractured cry liine-rock aquifers I • . icn arprIku lai Iikettontel Horitontat Huntoontal fierbantal Horzontal $100 hydra hydraulic hydrouOc hydraulic hydr lic � condom cooduc- condi. r duc- condos Sully tinily ttvity tinily {Layer 1) W.V. I) (Hilltops) (Wl ) &a l Vertical %wheat hydraulic hydraft e corrode. canduc- ty unity (LeYer O Drain Drain Re- cenduc- condo. charge Lance toner e (Chiarry) tl 3h 27.8 34:9 31.2 tro13 vixuA33 27,8 ttP I S f),000U3 i 0 0101% n,tiil0Oll 367 poi4 ttttto'Ke3tt a ? tr ill.t 01)0 143 #tte 1111 04 r-1 laydnautic c cduni►ity. t °fir r i�r S, 1u 4 raa bilk), (MM Thole rune ittw u a. c ealt ur t -worn luuletom tht4 mcl, t1ru`IIao. 52 Analyticatend Numeric& Salutation -al the StaadyState Hydrologic Effedsd Mining Aggregate In Hypothetical Randand- GraVet teed Fractured Crystalline -Rea by a remit zone), the sensitivity for horizontal hydraulic conductivity of the fault zone was small compared to the sensitivity for horizontal hydraulic conductivity of the surrounding rock. In all simulations, simulated head had little sensitivity to the hydraulic conductance of drain cells used to simulate valleys. and simulated head was relatively insensitive to the conductance of drain cells used to simulate the quarry. The sensitivity for vertical hydraulic conductivity could only be calculated for simulation 10. which had more than one model layer Simulated head in simulation 10 had little sensitivity to vertical hydraulic conductivity in both layers. SUMMARY AND CONCLUSIONS Analytical solutions and numerical models were used to predict the extent of drawdown caused by mining aggregate below the water table in hypothetical sand -and -gravel and fractured crystalline -rock aqui- fers representative of hydrogeologic settings in the Front Range area of Colorado. A steady-state, two- dimensional analytical solution derived by Marinelli and Niccoli was used to predict the extent of draw- down caused by a circular pit or quarry in a homo- geneous. isotropic sand -and -gravel or fractured crystalline -rock aquifer, respectively, of infinite extent~.. A similar, one-dimensional analytical solution derived during this study was used to predict the extent of drawdown caused bya linear quarry in a homoge- neous. isotropic fractured crystalline -rock aquifer of infinite extent. Parameters used in the analytical solu- tions were varied independently over a range of values to simulate the effects of mining over a wide range of conditions. Results of analytical simulations indicate radius of influence was about 4,500 m fora circular pit in a sand -and -gravel aquifer under intermediate condi- tions. Radius of influence was about 400 m for a circular quatryy in a fractured crystalline -rock aquifer under intermediate conditions, and distance of influ- ence was 500 m for a linear quarry in a fractured crys- talline -rock aquifer under the same conditions. Radius (or distance) of influence increased as horizontal hydraulic conductivity, mine penetration of the water table, and mine radius increased and as recharge decreased. One -percent sensitivities were calculated for each parameter in the analytical solutions to eval- uate the influence of each parameter on simulation. results. Results of analytical sensitivity analyses under intermediate conditions in sand -and -gravel and frac- tured crystalline -rock aquifers indicate radius of influ- ence was most sensitive to mine penetration of the water table and least sensitive to mine radius. Radius of influence was equally sensitive to horizontal hydraulic conductivity and recharge. but the parame- ters had opposite effects on simulation because they are inversely correlated in the ground -water flow equa- tion. Numerical ground -water flow models were used to predict the extent of drawdown caused lay a pit or quarry under conditions that consider heterogeneity. anisotropy, and boundaries and to simulate complex Or unusual conditions that were not readily simulated by using analytical solutions. Six numerical simulations were presented for the effects of mining in sand -and - gravel aquifers, and six numerical simulations were presented for the effects of mining in fractured crystal- line -rock aquifers. Numerical simulations in sand -and -gravel aqui- fers predicted the hydrologic effects of mining in a homogeneous, vertically anisotropic aquifer of medium size and in homogeneous, isotropic aquifers of different sizes with different boundary conditions. Numerical simulations in sand -and -gravel aquifers also predicted the hydrologic effects of pits lined with slurry walls and the effects of pits that have been refilled with water and are undergoing evaporative losses. Drawdown caused by a pit in a medium-sized sand -and -gravel aquifer under homogeneous and isotropic conditions (simulation I) was compared to drawdown simulated using an analytical solutiort. Area of influence in the numerical simulation was smaller than in the analytical simulation because of boundary effects and additional sources of recharge in the numerical simulation. Area of influence fora pit in a medium-sized sand -and -gravel aquifer under homoge- neous but vertically anisotropic conditions (simulation 2) was nearly identical to that in simulation l . Area of influence for a pit in a large sand -and -gravel aquifer under homogeneous and isotropic conditions (simula- tion 3) was larger and more symmetrical than that in simulation 1 because more water discharges to the pit and aquifer boundaries were farther away from the pit. Area of influence was smaller and drawdown was greater fora pit in a small, hydraulically isolated sand - and -gravel aquifer under homogeneous and isotropic conditions (simulation 4) because aquifer boundaries were closer to the pit mei no recharge was contributed by general -head boundaries. Pits lined with imperme SUMMARY AND CONCLUSIONS 53 able slurry walls in a medium-sized sand -and -gravel aquifer under homogeneous and isotropic conditions (simulation 5) caused mounding to occur upgradient from the pits and drawdown to occur downgradient from the pits, Pits refilled with water after mining and undergoing evaporative losses in a medium-sized sand -and -gravel aquifer under homogeneous and isotropic conditions (simulation 6) had little hydro- logic effect on the aquifer because discharge from the refilled pits was small compared to the overall ground- water budget. Numerical simulations in fractured crystalline- rock aquifers predicted the hydrologic effects of mining in a homogeneous, isotropic aquifer and in heterogeneous. anisotropic aquifers. Drawdown caused by a quarry in a homogeneous, isotropic frac- tured crystalline -rock aquifer (simulation 7) was cornparedfo drawdown simulated using analytical solutions. Area of influence in the numerical simula- tion was larger than in the analytical simulation because aquifer transmissivity in the numerical simu- lation was greater. Area of influence for a quarry in a homogeneous, horizontally anisotropic fractured crys- talline -rock aquifer (simulation 8) was elongated in the direction of greater hydraulic conductivity. Area of influence for a quarry in a fractured crystalline -rock aquifer with lateral variations of hydraulic conduc- tivity (simulation 9) was smaller than in simulation 7 because zones of low horizontal hydraulic conduc- tivity beneath hilltops in simulation 9 limited expan- sion of the area of influence upgadient from the quarry, and zones of high horizontal hydraulic conduc- tivity along the major valley represented as a constant - head boundary caused heads downgradient from the quarry to be maintained near premining levels. Area of influence for a quarry in a fractured crystalline -rock aquifer with ground -water flow in deep. low -perme- ability fractures (simulation 10) was larger than in simulation 7 because the thicker aquifer in simulation 10 increased aquifer transmissivity. Area of influence for a quarry intersected by a hydraulically conductive fault zone in a fractured crystalline -rock aquifer (simu- lacion 11) was larger than in simulation 7 because the fault zone increased ground -water flow to the quarry. Area of influence fora quarry intersected by a low - conductivity fault zone in a fractured crystalline -rock aquifer (simulation 12) was smaller than in simulation 7 because the fault zone decreased ground -water flow to the quarry. Composite scaled sensitivities were calculated for each parameter used in the numerical models to evaluate the influence of each parameter on simulated hydraulic head. Numerical sensitivity analysis results for sand -and -gravel aquifer simulations indicated simulated head was most sensitive to horizontal hydraulic conductivity and the hydraulic conductance of general -head boundaries. Simulated head in the sand -and -gravel aquifers was less sensitive to riverbed conductance and recharge. and simulated head was relatively insensitive to vertical hydraulic conductivity. Numerical sensitivity analysis results for fractured crystalline -rock aquifer simulations indicated simu- lated head was most sensitive to variations in recharge and horizontal hydraulic conductivity. Simulated head in the fractured crystalline -rock aquifers had little sensitivity to vertical hydraulic conductivity and the hydraulic conductancce of drain cells used to simulate valleys. Simulated head was relatively insensitive to the hydraulic conductance of drain cells used to simu- late quarries. REFERENCES CITED Anderman. ER.. 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V.V., 2002. Stone (Crushed): U.S. Geological Survey Mineral Commodity Summaries. p. 156-157. Tiedeman, C.R., Goode, D.J.. and Hsieh. P.A., 1997, Numerical simulation of ground -water flow through glacial deposits and crystalline bedrock in the Mirror Lake area. Grafton County. New Hampshire: U.S. Geological Survey Professional Paper 1572, 50 p. Trimble, D.E., and Machette, M.N., 1979. Geological map of the greater Denver area. Front Range Urban Corridor, Colorado: U.S. Geological Survey Miscella- neous Investigations Map 1-856—H, scale 1:100.000. Western Regional Climate Center, 1997, Map plot of 1961- 1990 average annual precipitation contours: Western Regional Climate Center data available on the World Wide Web, accessed May 9.2001. at URL http://www.wrcc.dri.edu/pcpn/co.gif Wilburn. D.R.. and Lstnget W.H., 2000. Preliminary report on aggregate use and permitting along the Colorado Front Range: U.S. Geological Survey Open -File Report O0-258.22 p. Wilson. W.W., 1965, Pumping tests in Colorado: Denver, Colorado Water Conservation Board Ground -Water Circular l 1.361 p. 56 Analytical and Hammiest Simulation of the Steady --,State Hydrologic Meets ot Mining Aggregate in Hypothetical Sand -and -Gravel and Fractured Crystalline -Rock Aquifers APPENDIX G-5 GWIP LLC Letter re: Wells with Permit Nos. 113762, 1472 and 89706 GREAT WESTERN INDUSTRIAL PARK Dean Brown Phone: (303) 398-4575 dbrown@broe.com February 20, 2023 Via U.S. Mail and Email (julie.mikulas@martinmarietta.com) Julie Mikulas Martin Marietta Materials 1800 N Taft Hill Road Fort Collins, CO 80534 Re: GWIP Wells with Permit Nos. 113762 and 1472 Dear Julie, Per your request, we have investigated the ownership, well permitting and use (or non-use as it turns out) of the wells with Permit Nos. 113762, 1472 and 89706, located in the Great Western Industrial Park. All three wells are located on land owned by GWIP, LLC ("GWIP") and, as appurtenances to said property, the wells themselves are owned by GWIP. Although the well with Permit No. 113762 is permitted for domestic and livestock watering use, the well is not used for domestic purposes and there is no longer a residence able to utilize said well. The well is actually not being used for any purpose and there are no plans to revive use of the well. If the well is ever used again, it will not be used for domestic purposes. The well with Permit No. 1472 is permitted for irrigation use only. Under Colorado law, for the well to be used for irrigation purposes, it would need to be augmented. The well is not augmented; and it is not being used. There are no plans to revive use of the well. If the well is ever used again, it will not be used for domestic purposes. The well with Permit No. 89706 is permitted for domestic use and irrigation of one (1) acre. The well is not used for domestic purposes. The residence that once used the well is being served domestic potable water by the City of Greeley. The well in the future will not be used for domestic purposes. Please let me know if you need anything else. GWIP, LLC, A ColoradoAmited liability company By: Dean Brown 00597648/1) 2005 Howard Smith, Avenue East, Windsor, CO 80550 (303) 398-4575 Pvbs;C Rev;e(A) to/31x122 SG COLORADO Division of Reclamation, Mining and Safety Department of Natural Resources RECEIVED OCT 13 2022 WELD COUNTY COMMISSIONERS NOTICE Consideration of 112c Construction Materials Reclamation Permit Application DATE: October 7, 2022 TO: Weld County Commissioners 1150 O St Greeley, CO 80631 RE: Windsor East Mine, File No. M-2022-042 Please be advised that on October 7, 2022, Martin Marietta Materials, Inc., whose address and telephone number are 1800 N. Taft Hill Road, Fort Collins, CO 80521; (970) 407-3631, filed an application to conduct a(n) Surface mining and reclamation operation, at or near Section 36, Township 6N, Range 67W, 06th Principle Meridian, in Weld County. Please be advised that the permit area may be located in more than one Section, Township, and Range. Affected lands will be reclaimed to support a(n) Developed water resources post -mining land use. The application decision date is scheduled for January 6, 2023. A copy of the application is available for review at the Weld County Clerk & Recorder's office and at the office of the Division of Reclamation, Mining and Safety. The application, as well as all other permit documents, can also be viewed at https://dnrweblink.state.co.us/drms/search.aspx by searching M2022042 in the "Permit No" field. A user guide is available to help first time users of the imaged document system and can be viewed at https://drive.google.com/file/d/118OUdf Mpjo3kxIHkP5hMH-w7MeStxX7/view. To be considered in the review process, comments or objections on the application must be submitted in writing within twenty (20) days of the date of the last newspaper public notice. You should contact the applicant for the newspaper publication date. The Office will assume you have no comment or objection to the proposed activity if none are received by the end of the public comment period. If you need additional information or have any questions regarding the above -named application, please contact Peter S. Hays at the Division of Reclamation, Mining and Safety, 1313 Sherman Street, Room 215, Denver, CO 80203, by telephone at 303-866-3567 x 8124, or by email at Peter.hays@state.co.us. M -AP -05A Physical Address: 1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 Mailing Address: DRMS Room 215, 1001 E 62nd Ave, Denver, CO 80216 httos://drms.colorado.eov Jared S. Polls, Qgv mmpc Dan Gibbs, Executive Director I Virginia Brannon, Director CC:PL(TP/MW/DA), pw(m/ER/C►-1/cg) to/26/22 2O22- 22.g3 Hello