Laserfiche WebLink
washed and other factors such as the type of clays encountered, processing equipment <br />efficiencies, etc. <br />The smallest quantity of water entering the mine is the incidental category. This category <br />includes leakage from water lines, dust control watering in the haulage entries, and <br />washdown water used in the slope and other locations. It has been assumed that 10% of <br />the water used for production equipment will be used under this category. <br />Outgoing Water As coal is mined, water is added by dust control sprays on the <br />continuous miners, the longwall shearer and at transfer points along the conveyor belt <br />system. This water is then carried out of the mine as surface moisture on the raw coal. <br />This added coal surface moisture represents a 4% increase in the raw coal moisture <br />content. The raw coal tonnage produced during this reporting period was 1,923,267 tons. <br />Water leaving the mine as ventilation humidity represents a large quantity in the water <br />balance. The temperature of the exhaust ventilation air is almost constant, at 60 F. <br />Up until the commissioning of the new mine dewatering system in May 2012, no <br />underground water had been pumped out since January 1996. Water encountered in the <br />active areas of the mine was pumped to the mined out D seam area for storage. During <br />2011 -12 16.03 gpm was pumped to the D seam on average. <br />In May 2012 a new dewatering system was commissioned to pump excess mine water to <br />the surface for treatment, storage, and potentially discharge. An average of 9.97 gpm was <br />pumped to the surface. No discharge of the dewatering waters through the associated <br />NPDES outfall occurred during the water year as most of the water was allowed in <br />infiltrate through multiple ponds. <br />2.2.1.6 NPDES Discharges At present, BME has 12 NPDES outfalls. Outfall 001 <br />discharged once during this monitoring period. This discharge was in compliance with <br />applicable discharge standards. Outfall 026 at the sump dewatering holes has not <br />discharged since the January 1996. The NPDES permit was renewed effective October <br />1, 2007. Outfall 029 was added to the permit to allow for pumping, treatment and <br />discharge of B -seam water from the mine workings to the surface. The facilities <br />associated with this system were constructed and commissioned in May of 2012. No <br />discharge has occurred through Outfall 029 to date. <br />Sample results for the NPDES outfalls are provided in Appendix F. Only Outfall 001 <br />discharged once during the water year. <br />10 <br />