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<br />' mining flow for relatively short periods {hours or days), in the form of profuse drips, and then <br />gradually dry out as the flow stops and the ventilation air carries the moisture out of the mine. <br />These areas are generally associated with stackrock in the roof. Stackrock is a sandstone <br />laminated with very thin layers of silty carbonaceous material. These laminations range in <br />' thickness from a few inches to a few millimeters thick. Water in the stackrock appears to be <br />connate in origin and not from the rechargeable groundwater systems. Yrtually all of the geologic <br />water enters the mine from the surrounding strata from broken rock in the gob behind the longwall <br />' face. BME believes there was insignificant amount of seepage during the 1996-1997 water year. <br />1 The smallest quantity of water entering the mine is the incidental category. This category includes <br />leakage from water lines, dust control watering in the haulage entries, and washdown water used <br />in the slope and other locations. It has been assumed that 10% of the water used for production <br />equipment will be used under this category <br />.O~u poing Water AS coal is mined, it is wet by dust control sprays on the continuous miners, the <br />' longwall shearer and at transfer points along the conveyor belt system. This water is then carried <br />out of the mine as surface moisture on the raw coal. This added coal surface moisture represents <br />t a 2% increase in the raw coal moisture content. The raw coal tonnage produced during this <br />reporting period was 1,493,142 tans. <br />' Water leaving the mine as ventilation humidity represents a large quantity in the water balance. <br />The temperature of the exhaust ventilation air is almost constant, ranging from 60° in winter <br />months to 63°F in summer months. The relative humidity of this air ranges from 80% in the <br />summer to 95% in January and February. Throughout the year, except for the months of June, <br />July and August, the ventilation air is warmed as d passes through the mine. This increases its <br />' moisture carrying capacity and the air picks up considerable quantities of moisture wherever there <br />is water available. During the summer months the air is actually cooled, however, the difference <br />in relative humidity still allows the exhaust air to carry away more moisture than is brought in with <br />' the intake air. <br />t 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 <br />(PP2). Then all water discharged from the mine was discharged at the sump dewatering holes <br />' shown on Plate 1. During this year approximately 68°~ of the total was discharged from SDH-2 <br />(1,123,340 gallons), and none from SDH-3 and 32% from SDH-5 (520,950 gallons). This water <br />' is further discussed in the next section. <br />No underground water is being pumped out since the fire episode. For the remaining life of the <br />' D-Seam mine (about four years), the underground water will be left to fill the mined out areas. <br />' 13 <br />1 <br />