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c <br />• _ - HYDROLOGIC-IMPACTS -.--_- _ . _~ _ <br />1983 <br /> <br />t?ine inflows do not present a major problem at the Orchard Valley Mine. Approx- <br />imately 300,000 gallons of connate water were produced from subsidence induced <br />fracturing of roof strata from the 2 1/2 ldest Panel. The inflows were from lith- <br />ologically controlled, perched water table conditions which were damp or dripping <br />upon initial exposure. k'hen pillar recovery commenced, the caving of the sand- <br />stone paleo-channel produced approximately 3 1/2 to 5 gallons per minute, (CWI <br />1983), for approximately 60 days. <br />The 9 East Submain encountered dripping conditions from a sandstone paleo-channel <br />approximately 6 to 8 feet from the immediate roof. In that particular case, the <br />dripping roof signaled impending instability and roof falls. The dripping condi- <br />tions commenced upon initial development, continued for several days, and usually <br />stopped when a roof fall event occurred. <br />The 1 South Panel off the 8 East Submain encountered minor water inflow or damp <br />conditions from the floor and ribs in close proximity to the burnline-outcrop. <br />These conditions ceased after several days of exposure. The oxidized and <br />• weathered nature of the coal seam near the outcrop probably slightly increased <br />the permeability, and storage capacity of extreme localized extent. <br />The 8 North Submain has also encountered damp ribs and floor. These conditions <br />are the probable result of proximity to the abandoned Farmer's Mine. Exploration <br />activities conducted during the summer of 1983 determined the workings to be at <br />least partially flooded. Damp mining conditions will probably persist until the <br />Farmer's Mine is effectively drained. • <br />The !north I and North II Main entryways have exposed small scale meandering sand- <br />stone, paleo-channel deposits. Upon initial mining, these paleo-channel deposits <br />drip water for several days and subsequently dry up. The fault encountered at <br />crosscut X71 also dripped water in North II. In conjunction with the minor quan- <br />tity of water, a petroliferous substance was also discharged. The association of <br />water and petroleum (?) suggests a non-meteoric origin of Orchard Valley Mine <br />inflows in some cases (refer to the Nline Inflow Map). <br />Colorado 5lestmoreland Inc. is fortunate because mine inflow conditions at the <br />Orchard Valley t^ine are vastly different from neighboring operations, such as <br />'J. S. Steel's Scinerset Mine •,.'~ich discharo_es 18S acre-feet per year (U.S., 0.0.1., <br />October 1903). <br />-2- <br />