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Client: Mountain Coal Company CO-0038766 SCG Project No.: 305141 <br />Site: West Elk Mine Energy 017 <br />The acute tests were started on 06-07-2005 for the Daphnia magna and on 06-07-2005 <br />for the Fathead minnows. The tests were performed according to the procedures outlined in <br />USEPA' and the Colorado Department of Public Health and Evironment^. The Daphnia magna <br />tests were conducted over a 48-hour period, while the fish were exposed for 96-hours. Exposure <br />concentrations include 0%(control), 1.9%, 12.5%, 25%, 50% and 100% effluent mixtures. <br />Moderately hard laboratory reconstituted water was used as the dilution water and control for the <br />tests. Reconstituted water is prepared by adding sodium bicarbonate, calcium sulfate, <br />magnesium sulfate and potassium chloride to deionized water. <br />A total of 20 organisms at each concentration were used for the Daphnia magna tests. <br />Daphnia magna were exposed in 30 m] plastic disposable beakers, each of which contained 15 <br />ml of the effluent mixture. Fathead minnow tests were performed in 250 m] plastic cups <br />containing 200 ml 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, LC50's <br />were calculated using EPA's TOXDAT Multi-Method Program according to the binomial, probit <br />or moving average methods. <br />RESULTS <br />The data sheets for the acute tests are located in Appendix 2. Survival in the <br />Daphnia magna test was 55% in the 100% effluent and ranged from 80% - 100% in the <br />remaining effluent concentrations. Control survival was 100%. <br />No survival effects were measured in the Fathead minnow test. Survival in the 100% <br />effluent was 100% and ranged from 95% - 100% in the remaining concentrations. Control <br />survival was 100%. <br />DISCUSSION <br />The sample collected, showed no significant toxicity to either test species. The dischazge <br />passes WET (Whole Effluent Toxicity) test guidelines for this quarter. <br />The SeaCrest Group 6 <br />