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~t <br />2.04.5 page 6 <br />on water quality in Hay Gulch attributable to the King Coal Mine, <br />because the two ponds collect all disturbed runoff water. The <br />quality of this water is monitored. Samples at the discharge end <br />of the channels and pipes determine any changes in the quality of <br />the runoff, <br />Water contained in the sediment ponds is not discharged into <br />the meadow, but allowed to evaporate. The only water to be <br />discharged from the ponds will be precipitation exceeding a ten <br />year - twenty four hour storm event. This is in accordance with <br />the requirements of National King Coal's N.P.D.E.S. permit No. <br />CO-0036561 (included with this exhibit). An air pollution emission <br />permit is also attached. <br />The sediment ponds outlets or spillways are constructed of <br />thirty inch diameter culvert pipe. <br />By regulation, the mining company must manage water expected <br />in a 24-hour storm event predicted to occur once every ten years. <br />The National Oceanic and Atmospheric Precipitation Frequency Atlas <br />of the Western United States - Colorado predicts the 30-year 24- <br />hour precipitation event at the mine site to be 2.5 inches. <br />Disturbed acreage at the King Coal Mine surface site is 8.36 acres. <br />The sedimentation ponds must provide 1.6 acre feet, assuming 100 <br />percent runoff. Currently the west pond will handle 1.62 acre feet <br />and the east pond will handle approximately 1.3 are feet. The <br />sedimentation ponds were constructed by excavation. A front end <br />loader was used to push dirt and spoil material into banks <br />surrounding the pond perimeter. <br />Two wells supply fresh water to the mine. One of these is <br />located in the meadow of Hay Gulch off the permit site. Water from <br />the two wells is pumped into the mine via one four inch water line. <br />All water lines are buried beneath the frost line. A water right <br />agreement for use of the meadow well is included with this exhibit. <br />This water supply is a result of a cooperative effort between the <br />surface landowner, National King Coal, Inc., and the Soil <br />Conservation Service for incorporation into a field drainage <br />program. Without this arrangement, water gradually builds up on <br /> <br />