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No underground water has been pumped out since January 1996. Water encountered in <br />the active areas of the mine is pumped to the mined out D seam area for storage. During <br />2010 -11 36.5 gpm was pumped on average. About ten gallons 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 12 NPDES outfalls. Outfall 001 <br />discharged once during this monitoring period. This discharge was in compliance with <br />applicable discharge standards. Outfall 026 at the sump dewatering holes has not <br />discharged since the January 1996. The NPDES permit was renewed effective October <br />1, 2007. Outfall 029 was added to the permit to allow for pumping, treatment and <br />discharge of B -seam water from the mine workings to the surface. The facilities <br />associated with this system were not constructed by the end of this reporting period. <br />Sample results for the NPDES outfalls are provided in Appendix F. <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 outfall 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 />• <br />• <br />In the early stages of WET testing, the associated H in the effluent was <br />deemed to be a potential toxicant. However, a WET testing done by <br />ENSR Consulting in June 1990 after removing H by aeration still <br />showed toxicity. This result indicated that some other factor(s) also <br />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 <br />study considered pH effects, volatile organic carbon, metals chelation, <br />aeration, total dissolved solids (TDS) and ammonia. The lab determined <br />high TDS (chlorides) as the primary cause of the toxicity. However, a <br />10 <br />