2012-10-25_HYDROLOGY - C1980007 (2)

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"; �.'MOLJFItahl COO -A C01111patly October 19, 2012 Ms. Kelly Morgan ro Compliance Monitoring and Data Management lnit Colorado Department of Public Health and the Environment Water Quality Control Division (WQCD) P -132 4300 Cherry Creek Drive South Denver, CO 80246 -1530 Re: Mountain Coal Company, LLC - West Elk Mine CDPS Permit No. CO- 0038776 Discharge ]•Monitoring Reports — Third Quarter 2012 Dear Ms. Morgan: C.lGBo Cb} kweltCC�a� ci �:,vy�.coi � Attached are Mountain Coal Company, LLC's (MCC) Discharge Monitoring Reports (DMRs) for the third quarter of 2012. During the third quarter, there were no discharges from out-falls 004, 005, 008, 009, O1 l - 013, 014, 016 - 018 and 019. Discharges occurred at Outfall 007, which is an internal outfall from MCC's waste water treatment plant (WWTP), and at Outfall 015. On July 20, August 02, and September 20, 2012, MCC notified the Division by telephone of the fecal coliform and total suspended solids (TSS) daily limit exceedances from Outfall 007. There also were 30 -day average exceedances of TSS and total iron at Outfall 015, and of TSS at Outfall 007. The Outfall 015 exceedances were the result of a single, small discharge, but there were no daily limit exceedances. As you directed in those telephone notifications, these exceedances are further described below. Outfall 007 Both the TSS and fecal coliform exceedances at Outfall 007 were believed to be a result of outside influences on the WWTP effluent as it entered and passed through the existing, open "polishing" pond. When the WWTP and polishing pond were originally built, they were located at the western edge of the mine site and coal handling areas. However, coal handling and storage areas located in close proximity to the WWTP and polishing pond have been recently expanded. This has increased the potential for coal dust and sediment to enter the pond. In addition, impacts from wildlife appear to be affecting the water quality of the polishing pond. This has subsequently been confirmed by comparing analyses of the effluent before and after the polishing pond. The polishing pond was originally the only pond that the WWTP effluent entered, providing additional chlorine contact and settling, before being discharged at Outfall 007 to the North Fork of the Gunnison River. With other changes to the ?dine facilities and drainage systems downstream of Outfall 007 over the past 20+ years, flows from Outfall 007 have been routed to and contained within another pond on the mine site. As such, Outfall 007 is an "internal discharge" as it does not directly enter state Waters.