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August 3, 2012 <br />Dear Ms. Morgan, <br />COAL <br />COMPANY , <br />5731 State Highway 13 w Meeker, Colorado 81641 <br />Ms. Kelly Morgan <br />Colorado Department of Public Health and Environment <br />Water Quality Control Division <br />4300 Cherry Creek Drive South <br />Denver, CO 80222 -1530 <br />970- 824 -1500 <br />AUG 01 ` S3't <br />pivision of Kec rarnanon, <br />Mining and Safety <br />RE: Correction to Upset Conditions Report of Total Suspended Solids at Outfall 010A, Colowyo <br />Coal Company L.P. (Colowyo) CDPS Permit No. CO- 0045161; and Request for Waiver of <br />Primary Quality Standards and Utilization of Alternate Limitations due to Precipitation. <br />On July 31, 2012, we discussed the upset conditions for Total Suspended Solids (TSS) at <br />Colowyo's Outfall 010A during July 2012. Colowyo sampled Outfall 010A on July 18, 2012 and <br />laboratory analysis was received on July 26, 2012. The results indicated a TSS concentration of <br />148 mg /L. The permit limits TSS to 70.0 mg /L as a Daily Maximum. However, upon further <br />review we determined that the TSS limit was not applicable during the discharge based on the <br />application of Alternate Limitations due to precipitation. <br />While Colowyo believes that the TSS concentrations reflect development of algae in the pond <br />due to regional uncharacteristic weather patterns which qualifies as an upset condition, the <br />facility also received precipitation on July 16, 2012. Pursuant to Section A.1 of the current <br />permit under Alternate Limitations, "Any discharge or increase in the volume of a discharge <br />caused by precipitation within any 24 -hour period less than or equal to the 10 -year, 24 -hour <br />precipitation event (or snowmelt of equivalent volume) may comply with the following <br />limitations subject to burden of proof requirements described in Part I.A.3." Therefore, <br />Colowyo will be reporting the alternate limitation (settleable solids) data on the Discharge <br />Monitoring Report for July 2012. <br />The burden of proof requirements described in the permit include: 1) showing the "majority of <br />the loading from any discharge has to consist of storm runoff'; 2) showing the "exceedance of <br />the applicable limitations was caused by precipitation and not mine water, through comparison <br />of the loading from each source "; and 3) proving "that discharge occurred within 48 hours after <br />measurable precipitation has stopped ". In terms of loading, East Taylor Pond (Outfall 010A) <br />does receive inflow from a small spring; however, flow rates are minimal, steady and contain <br />small concentrations of TSS (6 mg /L measured on June 21, 2012). No mine water is discharged <br />to this outfall from the facility. East Taylor Pond was dredged during August of 2011, and 2088 <br />yards of material was removed form East Taylor Pond. Please see attached climatological data, <br />sample analysis reports, and pictures taken of East Taylor Pond during the months of June and <br />July, to further support the application of alternate limitations. <br />