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Peabogq <br />Twentymile Coal Company <br />29515 Routt County Road #27 <br />Oak Creek, CO 80467 <br />970.879.3800 QQCJ <br />January 28, 2008 n ? <br />CF-? eQeoal fer! <br /> VX'j\S\0 26\6 <br />Ms. Tania Watson <br />Colorado Department of Public Health and Environment <br />Water Quality Control Division - Permits and Enforcement <br />4300 Cherry Creek Drive South <br />Denver, CO 80222-1530 <br />RE: PERMIT COG-850000, FACILITY NUMBER COG-850048 FOURTH QUARTER 2008 DMR <br />SUBMITTAL <br />Dear Ms. Watson: <br />Please find attached the above referenced discharge monitoring report for the period October 1, <br />2008 through December 31, 2008, for Outfall 001A/001W (site 10RT). Please forward to the <br />appropriate person. This is temporary emergency discharge permit. The discharge source is <br />groundwater, which is pumped from a portion our underground mine to prevent flooding. <br />Outfall 001A/001W discharged each week of the period. Exceedances were noted for total <br />recoverable iron only. Historic analysis of this groundwater had indicated TR iron typically in the <br />0.2 to 0.3 mg/I range, however we may be drawing from other portions of the underground <br />reservoir, which may account for the observed increase in concentration. Note that the <br />Twentymile Coal Company (TCC) had requested proposals for water treatment (e.g. <br />electrocoagulation & reverse osmosis blending) from multiple consultants. Initial proposals are <br />now under review. <br />WET testing was conducted in the fourth quarter for 001W. The initial result indicated that the <br />effluent was acutely toxic to Cerodaphnia. Subsequent accelerated testing indicated it was still <br />acutely toxic. TCC provided additional samples to the analytical laboratory in order for them to <br />conduct bench studies to try and pin down the parameter(s) of toxicity. High sulfate <br />concentrations may be the main problem. <br />Note that the 001W effluent discharges to a drainage channel that eventually connects with <br />Foidel Creek. The discharge then passes through a flat vegetated boggy area. The drop in water <br />velocity appears to allow enough resonance time for some effluent constituents to drop out and/or <br />mildly aerate. Three consecutive WET tests collected over the last three months from a site <br />located downstream of the boggy area (and upstream of the confluence of next creek that Foid I <br />comes in contact with) have all. TR iron concentrations at this downstream site has also pass d <br />permit requirements.