Laserfiche WebLink
significant trends or adverse impacts related to mining at Mines 5 and 6. <br />COAL <br />FLOWS <br />Plots of the measured discharges for the two #5 Mine discharge points are presented <br />in Figures 16 and 17. The flows are measured at the discharges by totalizing flow <br />meters on the dewatering sump pumps. The mean flow rate did not exceed the mine <br />inflow predictions from the Probable Hydrologic Consequences (PHC) evaluation. The <br />water produced in the No. 6 Mine is pumped underground to the No. 5 Mine sump and <br />where it then is pumped out of the No. 5 Mine Discharge point. The discharge from <br />the 7 North Angel Sump generally ranges from 250 to 500 gpm when the pump is <br />working year-round. The irregularity in the No. 5 Mine sump discharge was due to <br />pump failure which prevented discharges from this point in the first and second <br />quarters or 1994. Relatively high pumping rates occurred in the second half of the <br />year to compensate . No inflows from the mine floors have been observed to date. <br />WATER QUALITY <br />Summaries of the water quality data for the mine discharge are presented in Tables <br />19 through 22. The #5 Mine sump discharge is NPDES discharge point #003. The 7 <br />North Angle Discharge is NPDES discharge point #024. The #5 Mine discharge water <br />quality indicates a slight increase in dissolved solids concentrations over time. The <br />C-81-044 1994 AHR Page 6 <br />