Laserfiche WebLink
C7 <br />• <br />• <br />reduction in flow is due to stream channel infiltration and <br />evapotranspiration. The TDS plot indicates a decreasing trend. <br />- Surface Water Site SW-S2-11 (SSF11) This site monitors Fish Creek <br />upstream of its confluence of Cow Camp Creek. It is required to be <br />monitored May through July on a monthly basis, but only if either Sites <br />10 or 12 are flowing (for. this year, only in May). However, field <br />parameters and flow estimates may sometimes be provided voluntarily when <br />not required. This site is upstream of Seneca II Mine discharges. <br />- Surface Water Site SW-52-13 (SSF13) This site monitors Fish Creek <br />downstream of its confluences with Cow Camp Creek and Bond Creek. It is <br />monitored at the same frequency as Site il. The increase in TDS values, <br />from Site 11 to Site 13, was from 180 to 190 mg/1 (6% increase) in May <br />and 420 to 450 mg/1 (7%) in June. No TDS samples were collected in July. <br />This site displays a decreasing TDS trend. <br />On Page 7-247 of the Seneca II Mine Probable Hydrologic Consequences <br />(PHC), predictions were made for the TDS increases to be observed on <br />Fish Creek during the months of June and July due to discharges from the <br />Seneca II Mine. In June, an increase from 421 to 497 mg/1 (18%) is <br />predicted between SSF11 and SSF13. In July, an increase from 533 to 607 <br />mg/1 (13%) is predicted between SSF11 and SSF13. Neither lower Bond <br />Creek nor lower Cow Camp Creek was flowing in July this year. As stated <br />in the previous paragraph, a 6°s increase in TDS was observed between the <br />two sites in May, and a 7°s increase was observed in June. It appears <br />that the Seneca II Mine has little impact on Fish Creek. Water <br />discharged from the mine is lost to stock ponds, evapotranspiration, and <br />the alluvium as it flows through Twentymile Park. Dissolved solids from <br />mine discharges are diluted during the snowmelt runoff in March and <br />April (prior to the irrigation season) by high stream flows with <br />relatively low TDS concentrations. The natural conditions in Twentymile <br />Park appear to have a much greater impact on the water quality of Fish <br />Creek. <br />13 <br />