2016-07-28_REVISION - M1980244 (2)

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mining operation will"be located entirely in the vadose zone above the water table,and will only intersect meteoric water that infiltrates immediately above the mine workings". Please explain this discrepancy. What is the approximate depth to groundwater in the area of the proposed underground mine? What is the anticipated maximum depth of mining in this area? RESPONSE. The maximum expected depth for Amendment]] underground operations is 750 feet. There is no potential for underground mine operations proposed under Amendment I to intercept the regional water table in this area. • Page 4-5: The text states "Precipitation water infiltrating to groundwater through mine facilities located on the diatreme (mine areas,mine backfill, overburden storage areas, and reclaimed disturbed land)will pass by subsurface flow paths through the diatreme to the regional groundwater table and eventually flow to Fourmile Creek via the Carlton Tunnel portal".However,the northern portion of ECOSA and a portion of the East Cresson Mine —WHEX are located outside of the diatreme.Additionally, in Volume II, you mention that the underdrains installed under ECOSA have not been functioning properly, and some toe seepage is occurring. Please explain this discrepancy. RESPONSE: As discussed above, after reclamation, water infiltrating the area overlain by ECOSA and WHEX is expected to enter the diatremal bedrock, and proceed through the diatreme to Carlton Tunnel and thence to Fourmile Creek. The recent evaluation of the water levels in the overflow apron of the diatreme indicates that some water infiltrating at the extreme eastern edge of the diatreme, in particular in the thalweg of Grassy Valley, is now and has always been exiting the diatreme via upwelling into Grassy Valley at the location where the Precambrian rockmass outcrops. This water is not captured by the diatreme. The area where this capture has always taken place, and is expected to continue to take place in the future is shown on Plate 4 of the Hydrology Evaluation (Attachment 1). Seepage from the toe of ECOSA is and will continue to be collected in a ditch that extends the entire length of the toe. Flow so collected will be directed to infiltration or treatment, as appropriate. This procedure has already been implemented in response to afresh water pipe failure beneath ECOSA,protecting Grassy Valley from impact3. • Page 4-5: The text states "The naturally available calcium carbonate in the diatreme along the flow path for infiltrated water from mined rock prior to and including AM- 11 is more than 43 times the mass required to neutralize the products of oxidation of the sulfide minerals exposed by mined rock prior to and including the proposed AM-I L" However, this statement only holds true as long as rocks in the saturated zone remain saturated, meaning that mining activities are restricted to rocks above the saturated zone and/or the water table does not lower.As pointed out above,you state in this section that the proposed underground mining activities may penetrate the saturated zone.Please explain this discrepancy. RESPONSE. As discussed above, the maximum expected depth for Amendment I underground operations is 750 feet. There is little to no potential for underground mine operations to intercept the regional water table in this area. The discrepancy may have originated from underground plans that were originally accessed from the WHEX pit. The access point for underground operations proposed under Amendment 11 will be from the existing Chicago Tunnel portal. a Letter from CC&V/Newmont to Timothy Cazier dated June 9,2016, Re: Permit No. M-1980-244:Cripple Creek and Victor Gold Mining Company;Cresson Project; Fresh Water Pipe Line Release Update. Page 26 of 28