2012-02-28_REVISION - M1980244 (85)

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Aquatic Life, Class 2 Recreational, and Agricultural. The compliance point locations are "end of pipe" at Arequa Gulch and there is not an established mixing zone for "in- stream" compliance. The nearest perennial surface water body to the operation is Cripple Creek, which is approximately two miles south. In compliance with the provisions of the Colorado Water Quality Control Act (25 -8 -101 et seq., CRS, 1973 as amended) and the Federal Water Pollution Control Act, as amended (33 U.S.C. 1251 et seq.; the "Act "), CC &V is authorized to discharge to Arequa Gulch at two outfalls (i.e., water from the VLF underdrain system and treated process water from the External Storage Pond) in accordance with effluent limitations, monitoring requirements and other conditions set forth in the Discharge Permit for Arequa Gulch (Permit No. CO- 0043648). Except as allowed under the Annual Precipitation Exemption, no discharge is allowed from the VLF, pursuant to federal effluent guideline regulations at 40 CFR, Part 440.104. This limitation does not apply to any flows from the groundwater drainage system (underdrain system) underlying the VLF. The facility also has a Storm Exemption from Federal Effluent Limitations. These exemptions apply to the External Storage Pond outfall (treated process water). There have been no discharges under the Discharge Permit for Arequa Gulch over the past three years. Discharge Monitoring Reports (monthly) demonstrate that no discharges occurred over the period 2007 through 2010 to date and CC &V is not engaged in remedial activity. Additionally, although there is not a requirement to sample for cyanide under the General Stormwater Permit, CC &V has not had a stormwater release since 2007, according to CC &V Environmental personnel interviewed during this onsite audit. 4.6 Implement measures designed to manage seepage from cyanide facilities to protect the beneficial uses of ground water. The operation is: Discuss the basis for the Finding/Deficiencies Identified: The VLF is a zero discharge facility and currently employs three internal PSSAs (Phase I, II and IV). Solution within the PSSAs is piped to the beneficiation facilities at the ADR Plant. The ore storage liner system consists of a minimum one -foot thick soil liner placed on a prepared subgrade and overlain by geomembrane, which is then overlain by a leachate collection system embedded in a minimum two -foot thick layer of drainage cover fill material. The liner system within the PSSAs consists of a minimum of one -foot thick soil liner, overlain by geomembrane, overlain by solution collection fill material, overlain by geomembrane, which is then overlain by a minimum two -feet thick layer of Cresson Project Name of Mine • in full compliance ❑ in substantial compliance ❑ not in compliance...with Standard of Practice 4.6. September 22, 2010 Signature of Lead Auditor Date Page 16 of 36