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a: TRAPPER MINING INC@ July 22, 2010 CERTIFIED Colorado Department of Public Health and Environment WQCD-PE-B2 4300 Cherry Creek Dr. South Denver, CO 80222-1530 Subject: Second Quarter 2010 Colorado Wastewater Discharge Monitoring Reports Permit No. CO-0032115 To whom it may concern: RECEIVED JUL 3 0 2010 DivWon of W,,cianetlon, Uning and. SaWY Enclosed are Trapper Mine's Second Quarter 2010 Colorado Wastewater Discharge Monitoring Reports for the period 04/l/10-06/30/10. During this quarter, six NPDES outfalls were active. Outfalls 001, 002, 011 and 021 discharged throughout the quarter. Outfall 017 and 020 discharged during the beginning of April due to precipitation events in the form of snow and subsequent melting. Outfalls 005, 008, 009, 012, 013, 014, 015, 016, 018, 019, 022, 023 and 024 did not discharge during the quarter. Values reported on the enclosed DMRs represent the maximum (or minimum as applicable) monthly/daily values generated at each outfall during the quarter. Also enclosed are monthly NOAA weather summaries for the reporting period and WET test report forms as applicable. Three outfalls were sampled for WET analyses during the quarter. Two species acute tests were completed at outfall 011. No exceedances of WET test limitations were observed at any tested outfalls. Primary effluent limitations were exceeded at all outfalls during the quarter. Five of these exceedances were in direct response to snowmelt and or precipitation events resulting from snowfall on the site. Samples taken April 13, 2010 showed an exceedance of TSS at outfalls 002, 011, 017, 020 and 021 due to a quick warm-up and winter snow pack melting. The alternate limitations for Settleable Solids, applicable in the event of discharge caused by precipitation (or snowmelt) less than or equal to the 10-year, 24-hour precipitation event, was met at all outfalls. A single exceedance of primary effluent limitations for pH occurred at outfall 001 during the quarter. A reading of 9.1 was recorded on June 22nd. The outfalls at Trapper mine are direct discharges from sediment control ponds on the site. Watersheds and individual pond systems vary considerably across the site encompassing nearly 30 ponds. Outfall 001 is located at the final pond of a series of five settling ponds. Each pond discharges to the next until discharging from the final pond at the NPDES sampling site. The ponds are very mature and have developed rich and diverse plant and animal communities. Aquatic vegetation has continued to increase in the system, including rich algal blooms, especially in summer. As natural systems, the vegetative communities are not altered by the operator. Nor have these ponds required cleaning of sediment in recent years due to the majority of this watershed being reclaimed. Vegetative growth and other microorganisms flourish in these ponds. There is a multitude of factors that contribute to pH levels in a pond. Not all factors can be controlled or fully understood in a pond setting such as this one. Historically, pH has risen in this system each summer. The typical treatment for high pH has been the addition of C02 gas at the discharge point. When it was discovered that pH was slightly higher than the standard, C02 treatment was immediately initiated and the condition was corrected. Treatment is continuing at this outfall via COz addition and mechanical aquatic plant removal. P.O. Box 187 Craig, Colorado 81626 (970) 824-4401