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r~ <br />L J <br />• <br /> <br />Mountain Coal Company 1999 Annual Hydrology Report <br />West Elk Mine <br />Table 9 <br />Sedimentation Ponds Numeric Discharge Limits <br /> Sedimentetioo Ponds <br />Parameter end Time Period Diuhar a Limit <br />Total suspended solids (mg/L) <br />• 30-day average 35 <br />• 7-day average N/A <br />• Maximum 70 <br />Total dissolved solids (mg/L) <br />• 30-day average N/A <br />• 7-day average N/A <br />• Maximum Report <br />Oil and grease <br />• 30-day average No sheen <br />• 7-day average No sheen <br />• Maximum No sheen <br />Total iron (mg/L) <br />• 30-day average 3.5 <br />7-day average N/A <br />• Maximum 7.0 <br />pH (standard units) <br />• 30-day average 6.5-9.0 <br />• 7-day average 6.5-9.0 <br />• Maximum 6.5-9.0 <br />No visual sheen should be present. If sheen is present, total concentration <br />cannot exceed ] 0 mgtL. <br />Mine Water Inflows <br />estimated at 130 gpm during WY99. <br />While mine inflows continued during WY99, the volume of the inflows was significantly lower <br />and no new large inflows were encountered. Flow continued from the B East Mains (BEM) fault <br />and the 14 Southeast Headgate (14SEHG) fault, although flows from both faults diminished and <br />relocated as mining progressed downdip along the faults. MCC also experienced the usual small <br />inflows, which quickly subsided as development mining occurred. Total mine inflows were <br />BEM Fault Inflow <br />The flow from the BEM fault inflow continued during WY99, but as the downdip expressions of <br />the fault were mined through, the updip flow ceased and relocated to the downdip location. The <br />flow is in the 23HG sump, so a sample at the source is not feasible. All locations are shown on <br />Map I. <br />83/-09?.5?0 Page 19 Wright !rater Engineers <br />