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Client: Western Fuels CO-0000213 SCG Project No.: 310547 <br />Site: New Horizon Mine NPDES 011 <br />Ceriodaphnia dubia tests were conducted over a 48-hour period, while the fish were exposed for <br />96-hours. Exposure concentrations include 0% (control), 6.25%, 12.5%, 25%, 50% and 100% <br />effluent mixtures. Moderately hard laboratory reconstituted water was used as the dilution water <br />and control for the tests. Reconstituted water is prepared by adding sodium bicarbonate, calcium <br />sulfate, magnesium sulfate and potassium chloride to deionized water. <br />A total of 20 organisms at each concentration were used for the Ceriodaphnia dubia tests. <br />Ceriodaphnia dubia were exposed in 30m1 plastic disposable beakers, each of which contained <br />15ml of the effluent mixture. Fathead minnow tests were performed in 260ml plastic cups <br />containing 200m1 of test medium. Ten fish were used in each of the four replicates for a total of <br />40 fish per test concentration. <br />Exposure medium in each chamber was replaced every 24-hours and organisms surviving <br />at each concentration were counted and recorded. Routine measurements were made of <br />temperature, pH and dissolved oxygen in each concentration, before and after the water change. <br />Data Analysis <br />Data from the test(s) were analyzed on a personal computer. Where applicable, LC50s <br />were calculated using TOXCALC developed by Tidepool Scientific Software. <br />RESULTS <br />The data sheets for the acute tests are located in Appendix 2. Survival in the <br />Ceriodaphnia dubia test was 100% in the 100% effluent and 100% in all remaining effluent <br />concentrations. Control survival was 95%. <br />No survival effects were measured in the Fathead minnow test. Survival in the 100% <br />effluent was 100% and 100% in all remaining effluent concentrations. Control survival was <br />100%. <br />DISCUSSION <br />The sample, collected on 05-24-2010, showed no significant toxicity to either test species <br />at any effluent concentration. The discharge passes WET (Whole Effluent Toxicity) testing <br />guidelines for this sampling period. <br />SeaCrest Group 6