2010-07-26_HYDROLOGY - C1981008 (2)

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Client: Western Fuels CO-0000213 SCG Project No.: 310624 Site: New Horizon Mine 007 Fathead minnow Test Results Fathead minnow results are summarized in Table 3 and are provided on data sheets in Appendix 3. Survival was 98% in the 100% effluent concentration and ranged from 95% - 100% in the remaining effluent concentrations. Control survival was 98%. No statistically significant differences for survival were measured in any effluent concentration when compared to the control. The IC25 for survival was >100%. Table 3. Summary of Fathead minnow test results. Forty fish were exposed at each concentration. An asterisk (*) denotes a statistically significant difference from the control. No. Avg. Wt. Significant Difference Concentration Alive (m Min. Max. Survival Growth Control (0%) 39 0.302 0.294 0.313 6.25% 38 0.261 0.195 0.315 12.5% 40 0.274 0.235 0.322 25% 39 0.263 0.212 0.307 50% 39 0.270 0.225 0.323 100% 39 0.297 0.251 0.347 Average weight in the 100% effluent concentration was 0.297mg and ranged from 0.261 mg - 0.274mg per individual in the remaining effluent concentrations. Average weight for the control fish was 0.302mg for statistical analyses and 0.310mg for test acceptability criteria. No statistically significant differences were measured for growth in any effluent concentration when compared to the control. The IC25 for growth was >100%. Test Acceptabilitv Acceptable control survival was achieved in both tests. Similarly, Ceriodaphnia dubia reproduction and Fathead minnow growth in control organisms met required levels. PMSD was within the required limits for an acceptable test (Table 4). Table 4. PMSD for chronic test parameters. Sunival Growth Reproduction Result Fathead cower Upper 'Lower Upper Test Ceriodaphniu dubia Minnow bound bound bound bound param.,ters ' 12 30 13 47 dee d to be PMSD acceptable d numbers (% Minimum fall within significant limits or difference) N/A N/A _ 23.3 30.0 the test SeaCrest Group 8