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Outgoinu Water As coal is mined, water is added by dust control sprays on the <br />' continuous miners, the longwall shearer and at transfer points along the conveyor belt <br />system. This water is then carried out of the mine as surface moisture on the raw coal. <br />This added coal surface moisture represents a 4% increase in the raw coal moisture <br />' content. The raw coal tonnage produced during this reporting period was 2,442,938 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° F. <br />' No underground water has been pumped out since the fire episode. Water encountered <br />in the active areas of the mine is pumped to the mined out D seam area for storage. <br />Currently only 14 gpm is pumped on average. About one half of this is from pipe leaks, <br />' wash down, etc. The remainder is from groundwater encountered during the course of <br />mining. <br />' 2.2.1.6 NPDES Discharges At present, BME has 15 NPDES ouffalls. Only one ouffall, <br />DP-1, experienced discharge during this monitoring period. All discharges were in <br />compliance with applicable discharge standards. Outfalls 024 and 026 at the sump <br />dewatering holes have not discharged since the January 31, 1996 underground fire <br />' episode. <br />2.2.1.7 Whole Effluent Toxicity (WET) Testing No WET testing was conducted during <br />' the water year since there was no discharge of the underground water from the sump <br />dewatering holes or from ouffall 004 (Pond PP2). A history of WET testing at Deserado <br />' Mine follows below: <br />BME started the whole effluent toxicity (WET) testing program beginning in the fourth <br />' quarter of 1989. The mine water effluent was found to be toxic to the test species. <br />Accelerated 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, <br />1992, the BME staff reiterated the biomonitoring events, and various measures taken to <br />identify the toxicants and to reduce the toxicity. BME took the following steps to identify <br />potential toxicants. <br />• In the early stages of WET testing, the associated H2S 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 <br />toxicity. This result indicated that some other factor(s) also contributed to <br />the toxicity. <br />9 <br />