Laserfiche WebLink
r <br />' 63°F in summer months. The relative humidity of this air ranges from 809'° in the summer to 95% <br />in January and February. Throughout the year, except for the months of June, July and August, the <br />' ventilation air is warmed as it passes through the mine. This increases its moisture carrying capacity <br />and the air picks up considerable quantities of moisture wherever there is water available. During <br />' the summer months the air is actually cooled, however, the difference in relative humidity still allows <br />the exhaust air to carry away more moisture than is brought in with the intake air. <br />' Some of the water entering the mine is collected in sumps at various locations. In the past, this <br />water was eventually pumped out of the mine through the East Intake or to process pond two (PP2). <br />' All water discharged from the mine is now discharged at the sump dewatering holes shown on Plate <br />1. During this year approximately 569'° of the total was discharged from SDH-3 and 44% from <br />SDH-5. This water is further discussed in the next section. <br /> <br />1 <br /> <br /> <br /> <br /> <br /> <br />1 <br /> <br /> <br /> <br />1 <br />2.2.2.6 NPDES Discharges and Whole Effluent Testing At present, Western Fuels-Utah has 14 <br />NPDES ouffalls. Seven of these ouffalls have never experienced a discharge and an eighth has had <br />one discharge since construction 12 years ago. The vast majority of water is discharged from the <br />outfalls for the mine dewatering boreholes (SDH-2, SDH-3 and SDH-5). The water from SDH-2 <br />is discharged at ouffall 024 and the water from SDH-3 and SDH-5 is discharged at outfall 026. <br />There is no discharge from SDH-1. The NPDES discharge quality parameters for the water year <br />are summarized in Table 2-4. <br />Westem Fuels-Utah 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. 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, the <br />WFU staff reiterated the biomonitoring events, and various measures taken to identify the toxicants <br />and to reduce the toxicity. WFU has taken the following steps to identify potential toxicants. <br />• In the early stages of WET testing, the undisassociated 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. This <br />result indicated that some other factor(s) also contributed to the toxicity. <br />13 <br />1 <br />