HYDRO24194 - Laserfiche WebLink

Home Browse Search

COLORADO DEPARTMENT OF HFAI.TH, Water Quality Control Division Rationale - Page 3. Permit No. CO-0024562. III. RECEIVING STREAM: B. Receiving Water Data 1. Stream Low Flow: The flow which will be used to calculate effluent limitations is the lowest flow that occurs for seven days every ten years (q7-10). This flow has been determined by the Water Quality Control Division to be 6.8 cfs (4.39 MGD). The low flow that occurs for thirty days every three years (30E3) has not been used because the Division has determined that there Ss insufficient and conflicting information to develop a reliable estimate of the 30E3 low flow. As an additional requirement of this permit, the permittee shall be required to perform instream monitoring sufficient to determine the 30E3 low flow in Fourmile Creek. See page li of the permit for further discussion of this requirement. 2. Impacts on Downstream Water Supplies or Other Receiving Waters: There are no known water supply intakes downstream of this facility's discharge. IV. FACILITY DESCRIPTION A. Industry Description This permit is for the discharge from the Carlton Tunnel. The Carlton Tunnel is a drainage for the Cripple Creek Mining District. Slightly more than half of the area drained by the Carlton Tunnel is property owned or controlled by Cripple Creek and Victor Gold Mining Company. No underground mining activity has occurred since the permit was issued in October 1986. However, the company hopes to begin exploration and possible mining during the life of this permit. In anticipation of this activity, Pike's Peak has requested that a second set of limits based on the increased flow from the Carlton Tunnel due to mining activity be included in this permit. Since this is not an active mining operation, no federal guidelines have been promulgated for this type of operation. However, there are federal guidelines for the mine once it goes into production. These guidelines are found under 40 CFR 440, the Ore Mining and Dressing Point Source Category, Copper, Lead, Zinc, Gold, Silver, and Molybdenum Ores Subcategory (440.103). See Section VI.A.2 for further discussion. B. Wastewater Treatment Description Discharge point 001 is the bypass of the settling ponds and flows directly into Fourmile Creek. Discharge point 002 flows through a series of four settling ponds which discharge into Fourmile Creek. There is no other physical or chemical treatment of the discharge. A Class C operator is required for this facility.