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<br />The average daily mine discharge measured during the first half of 1989 <br />at the New Elk Mine is somewhat greater than that measured in 1980 when <br />the hydrologic report in Exhibit 6 was prepared, i.e., 85 gpm vs 73 gpm. <br />While some mining was done following the original study, the mine has not <br />been actively worked for several years. During mining, water was <br />consumed by absorption on coal exiting the mine, and in increased <br />humidities in the ventilation air, Currently, coal is not exiting the <br />mine and ventilation air volumes are reduced. <br />Mining activity might affect the stream/alluvial aquifer system of the <br />Middle Fork of the Purgatoire River. The Allen and Maxwell coal seam <br />aquifer subcrops below the Middle Fork of the Purgatoire River and in <br />Pete Canyon, north of the New Elk Mine. These streams and their alluvial <br />aquifers may recharge the coal aquifer. If so, the underground mine <br />workings may diminish the stream/alluvial aquifer systems through <br />increased recharge at subcrops and outcrops of the coal aquifers. <br />Dimunition of stream/alluvial aquifer systems may also occur as a result <br />of drying up of aquifer discharges (springs and seeps). Any excess water <br />entering the coal aquifer, however, is returned to the Purgatoire River <br />via the discharge of water from the mine. As a result, impacts on <br />quantity of water available from the stream/alluvial system of the <br />Purgatoire should be minimal. <br />Impacts to Pete Canyon are expected to be short-term in nature. Since <br />mining has ceased, pumpage of mine water has been stopped and the mine as <br />of July 1, 1989 and began to fill the mine. After filling of the mine, <br />dimunition of water from the surface systems of Pete Canyon should cease <br />and flows return to essentially the pre-disturbance levels. <br />The applicant has predicted that the stream/alluvial aquifer system will <br />be depleted by vertical leakage of surface waters through the overbu rden <br />strata into the mine cavity. For the New Elk Mine, however, downward <br />flow through the overburden in the absence of open fractures or <br />subsidence was calculated to be less than 5 gpm, an insignificant portion <br />of flow in the Purgatoire River stream-alluvial aquifer system. <br />Inspection of underground workings in the New Elk Mine beneath the <br />Middle Fork by Division personnel did not identify significant inflows of <br />ground water that could be attributed to leakage through the roof from <br />the stream/alluvial aquifer system. <br />An annual inflow study for the New Elk Mine was initiated in 1983 and <br />most recently conducted in June of 1989. This study consisted of the <br />mapping of all measurable mine inflows on a mine workings map, measuring <br />or estimating inflow rates, and determining inflow sources. The most <br />current information on the New Elk Mine inflows is contained in <br />Exhibit 10 of the renewal application. <br />Mine inflows are not concentrated in areas of the New Elk Mine which are <br />overlain by streams, but are dispersed throughout the mine. Thus, the <br />mine does not appear to have significant direct connection with the <br />stream or alluvial system. The mapping of mine inflows indicate that <br />faults and fractures are not a source of mine inflows. No point source <br />inflows were observed along faults and fractures. This indicates that <br />faults and fractures are healed with impermeable clays and/or are not <br />vertically extensive. <br />_19_ <br />