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<br />tests followed standard methods and included the use of standards to calibrate <br />equipment and assure proper operation. Tests were conducted in an incubator <br />maintained at 20 ± 1°C. Light regimes for tests followed a 16 hour light, 8 hour dark <br />cycle. <br />Sample Preparation <br />Five concentrations (100, 75, 50, 25, and 12.5%) and a control consisting of 100% <br />dilution water were used to test tf~e effluent. Exposure concentrations were prepared <br />by mixing effluent with the Calamity Draw receiving water. <br />Test Design <br />Guidelines for conducting the acute biomonitoring tests are contained in Weber <br />(1991). In summary, quadruplicate 30 ml plastic disposable beakers were used at <br />each concentration for the daphnid tests. Each vessel contained 20 ml of exposure <br />medium in which five neonates/young were placed, for a total of 20 organisms per <br />concentration. The exposure medium was changed in each container after 24 hours <br />and the test was terminated after 48 hours. Surviving organisms were counted daily <br />and measurements of temperature, pH, and dissolved oxygen recorded. Total <br />alkalinity, hardness, conductivity, total residual chlorine, and ammonia were measured <br />in the effluent and control at the start of the test. <br />The fathead minnova tests were conducted in 260 ml plastic disposable cups <br />containing 200 ml of the exposure medium. Five organisms in each of four replicates <br />were used at each concentration. The test was terminated after 96 hours with the <br />same procedures being followed as above. <br />RESULTS <br />In the Ceriodaphnia dubia test, 100% of the animals survived exposure to the <br />100% effluent and survival ranged from 95-100% in all the remaining effluent <br />concentrations. This compared to 100% control survival and 100% reconstituted <br />water survival. No statistically significant difference existed in survival between the <br />controls and the exposed animals. Summary sheets for this test are located in <br />Appendix 2. <br />The fathead minnow test had 95% sun~ival in the 100% effluent and 95-100°% <br />survival at all other exposure concentrations. Control survival was 100% and <br />reconstituted water survival was also 100%. Summary sheets are located in Appendix <br />3. <br />DISCUSSION <br />The effluent passes whole effluent toxicity test guidelines. <br />