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Outgoing Water As coal is mined, water is added by dust control sprays on the continuous <br />miners, the longwall shearer and at transfer points along the conveyor belt system, This water <br />is then carried out of the mine as surface moisture on the raw coal. This added coal surface <br />moisture represents a 4% increase in the raw coal moisture content. The raw coal tonnage <br />produced during this reporting period was 2,314,653 tons. <br />Water leaving the mine as ventilation humidity represents a large quantity in the water <br />balance. The temperature of the exhaust ventilation air is almost constant, at 60° E. <br />No underground water has been pumped out since the fire episode. Water encountered in <br />the active areas of the mine is pumped to the mined out D seam area for storage. Currently <br />' only about 8 gpm is pumped on average. <br />2.2.1.6 NPDES Discharges At present, BME has 15 NPDES ouffalls. Only one ouffall, DP- <br />1, experienced discharge during this monitoring period. All discharges were in compliance <br />with applicable discharge standards. Outfalls 024 and 026 at the sump dewatering holes have <br />' not discharged since the January 31, 1996 underground fire episode. <br />2.2.1.7 Whole Effluent Toxicity (WET) Testing No WET testing was conducted during the <br />' water year since there was no discharge of the underground water from the sump dewatering <br />holes or from outfall 004 (Pond PP2). A history of WET testing at Deserado Mine follows <br />below: <br />BME started the whole effluent toxicity (WET) testing program beginning in the fourth quarter <br />of 1989. The mine water effluent was found to be toxic to the test species. Accelerated <br />testing was conducted but the toxicity to the species continued. <br />In a meeting with Colorado Water Quality Control Division (WQCD) staff on January 31, 1992, <br />the BME staff reiterated the biomonitoring events, and various measures taken to identify the <br />toxicants and to reduce the toxicity. BME took the following steps to identify potential <br />toxicants. <br />• In the early stages of WET testing, the associated HzS in the effluent was <br />deemed to be a potential toxicant. However, a WET testing done by ENSR <br />Consulting in June 1990 after removing HzS by aeration still showed toxicity. <br />This result indicated that some other factor(s) also contributed to the toxicity. <br />• In September, 1990, ENSR Consulting was directed to conduct a "toxicity <br />characterization" study to identify the primary cause of the toxicity. This study <br />considered pH effects, volatile organic carbon, metals chelation, aeration, total <br />9 <br />