Laserfiche WebLink
<br />COAL <br />FLOWS <br />Plots of the measured discharges for the two #5 Mine discharge points are presented in <br />Figures 19 and 20. The flows are measured at the discharges by totalizing flow meters on <br />the dewatering sump pumps. The mean flow rate did not exceed the mine inflow <br />predictions from the Probable Hydrologic Consequences (PHC) evaluation. The water <br />produced in the #6 Mine is pumped underground to the #5 Mine sump and is accounted <br />for at the discharge from that point. The discharge from the 7 North Angle Sump generally <br />ranges from 250 to 450 gpm when the pump is working year-round. The decrease in the <br />#5 mine sump discharge is due to a pump failure in the first and second quarters of 1994. <br />No inflows from the mine floor have been observed to date. <br />• <br />WATER QUALITY <br />Summaries of the water quality data for the mine discharge are presented in Tables 19 <br />through 22. The #5 Mine sump discharge is NPDEs discharge point #003. The 7 North <br />Angle Discharge is NPDES discharge point #024. The #5 Mine discharge water quality <br />indicates a slight increase in dissolved solids concentrations over time. The plot of <br />dissolved solids presented in Figure 21 shows that the average dissolved solids in the #5 <br />Mine discharge water have increased from about 800 mg/I in 1982 and 1983 to <br />approximately 985 mg/I in 1994. This increase in dissolved solids appears to have leveled <br />off since 1986, with occasional spikes being observed. The average dissolved solids <br />• <br />6 <br />