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Tables 29 to 31. Plots of historic field conductivity for Foidel Creek are <br />' presented on Figures 17 and 20. <br />The base levels of field conductivity measured during spring runoff, was <br />approximately the same for both the upstream and downstream sites on Foidgl <br />' Creek. It is approximately 1000 mmhos/cm. Since 1981 the base level fbr <br />dissolved solids at the downstream site has been increasing. During <br />irrigation season the field conductivity at Station 800 is approximately <br />' 2400 umhos/cm and at Station 8 is approximately 3000 umhos/cm. A <br />difference between the levels at the two stations was evident before the <br />' beginning of underground mining; therefore, it is at least partly due to the <br />effects of surface mining. The discharges related to surface mining are <br />' much greater than the underground mining discharges during the spring runoff <br />and are still greater during the irrigation season. Therefore, the increase <br />in the spring runoff dissolved solids levels is probably due primarily to <br />the effects of the surface mine. The increase in the salt content of the <br />water during the irrigation season is at least partly due to the effects of <br />' the underground mining. <br />' The suspended solids level upstream and downstream of the mine portal are <br />very similar and no significant impact on suspended solids levels is <br />' evident. Other than increased levels of sodium, sulphate, and SAR in the <br />stream no other significant water quality impacts at least partly due to <br />underground mining have been detected. The increase in SAR levels during <br />irrigation season is not sufficient to cause material damage. <br />' The dissolved solids levels in the upstream station on Fish Creek Station 16 <br />are lower than those in the two downstream stations (1002 and 1003). This <br />is most apparent during the low flow times of the year. This difference is <br />small, approximately 300 to 400 mg/1. It is probably due to <br />evapotransporative effects and impacts from naturally saline bedrock <br />discharge to Fish Creek as it meanders through Twentymile Park. Since the <br />' underground mine is not presently impacting Fish Creek the data is presented <br />for baseline purposes only. <br /> <br />1 <br />- 7 - <br />