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1 <br />1 I;aolny Water The production equipment utilizes water for dust control and cuttings removal in roof <br />bolting. Water used by equipment is based on 539 shifts worked by continuous miner sections and <br />' 331 shifts worked by the Iongwall. The continuous miner sections use 80 gpm and operate about <br />3 hours per shift (the rest of the time is spent moving, etc.). The Iongwall equipment uses 140 gpm <br />' of water for about 7 hours per shift. <br />The amount of water entering the mine as ventilation intake air humidity is based on monthly mean <br />temperatures from Figure II.C-2 on page II.C-9 of the Mining Permit and the yearly mean relative <br />humidity of 56% found on page II.E-1 of the Mining Permit. The absolute humidity, the actual <br />' amount of water in the air, is calculated from these data and an average ventilation quantity of <br />525,000 cubic feet per minute. <br />' The amount of water entering the mine from the surrounding strata is partially estimated by <br />identifying all known seep areas and estimating the flow rate from each. During January 1994, a <br />' survey of the accessible areas of the mine workings was conducted to identify the location and flow <br />rates of all seeps. The locations and flow rates of the seeps are shown on Plate 1. Due to the very <br />low flow rates measured, the flow rates are shown in gallons per day. Most, if not all, of this water <br />' leaves the mine in the form of humidity in the ventilation air flow. There are very few locations in <br />the mine that produce water over the long term. Most wet areas encountered during mining flow for <br />relatively short periods (hours or days), in the form of profuse drips, and then gradually dry out as <br />' the flow stops and the ventilation air carries the moisture out of the mine. These areas are generally <br />associated with stackrock in the roof. Stackrock is a sandstone laminated with very thin layers of <br />' silty carbonaceous material. These laminations range in thickness from a few inches to a few <br />millimeters thick. Water in the stackrock appears to be connate in origin and not from the <br />rechargeable groundwater systems. Yrtually all of the geologic water enters the mine from the <br />' surrounding strata from broken rock in the gob behind the Iongwall face. <br />t 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. <br />1 <br /> <br /> <br /> <br /> <br />Outflolnfl Water As coal is mined, it is wet by dust control sprays on the continuous miners, the <br />Iongwall shearer and at transfer points along the conveyor belt system. This water is then carried <br />cut of the mine as surface moisture on the raw coal. This added coal surface moisture represents <br />a 2% increase in the raw coal moisture content. The raw coal tonnage produced during this <br />reporting period was 2,046,420 tons. <br />Water leaving the mine as ventilation humidity represents a large quantity in the water balance. The <br />temperature of the exhaust ventilation air is almost constant, ranging from 60° in winter months to <br />12 <br /> <br />