Laserfiche WebLink
1 <br /> <br />due to the effects of snow melt and high rainfall diluting the water. The <br />' data from the Yampa River stations shows that the natural higher dissolved <br />solids content of the Williams Fork River during .low flow periods produces <br />an increase in the downstream electrical conductivity of the Yampa River. <br />' Due to the closure of the No. 9 Mine, water quality sample collections in <br />the Yampa River ceased in October, 1985. <br />' SPRINGS <br />Spring flow <br />' Three springs in the mine site area are being monitored. These springs <br />are the No. 1 Strip Pit discharge, North Spring, and the Haxton Spring. <br />The No. 1 Strip Pit discharge is a NPDES monitoring point. There are a <br />' few other springs and local permanent "damp spots" in the area; however, <br />their combined flow is less than ten gpm and are therefore not <br />significant. The 1985 measured discharges for the No. 1 Strip Pit are <br /> presented on Figure 29 and the discharges for the other two springs are <br />' presented on Table 30. All of the discharges show a normal seasonal <br /> variation in flow. That is, the high flows occur during the snow-melt <br /> runoff period and low flows in the winter and early spring; with some <br />' spring flows being so low that they become too low to measure, inpart due <br /> to freezing. <br /> The average discharge from the No. 1 Strip Pit was 23 gpm. The average <br />' discharges from the other springs are shown on Table 30. Measurable flows <br /> at the Haxton Spring were only observed twice. The average flow from the <br /> North Spring was 10 gpm. Average spring flows were lower in 1985 than in <br />1984 due to the lower runoff. <br /> Water Quality <br /> Summaries of the water quality data for the springs is presented on Table <br /> 31 to Table 36. No significant changes in the spring water quality are <br /> evident. <br /> IMPACTS AND FUTURE MONITORING <br />' No significant unpredicted adverse impacts were detected from the 1985 <br /> hydr-- ~ogtc moni~ing progr=am.-7he only significant variation from the <br /> predicted impacts was the less than predicted declines in the Middle <br />' Sandstone. This is probably due to changes in the location of the main <br /> area of mining in the No. 5 Mine and an increase in recharge. In <br /> addition, the No. 9 Mine does not appear to have had any impact on the <br /> White Sandstone. Water levels in the White Sandstone appear to be <br /> responding to natural changes in recharge and not to the mine dewatering. <br /> <br />' -5- <br />