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1 <br />' CHADWICK & ASSOCIATES, INC. <br />' 3 February 1994 5575 South Sycamore Street, Suite 101 <br />Llttletaa, Colorado 80120 <br />Phone (303) 794-5530 <br />Tim Mossman Fax (303) 794-5041 <br />' Kerr Coal Co. <br />1130 Country Rd. 29A <br />Box 487 <br />' Walden, Colorado 80480 <br />' Dear Mr. Mossman: <br />Enclosed aze the results of the toxicity tests performed from 20 to 28 January 1994. A Ceriodaphn7a <br />' survival and reproduction test and a fathead minnow survival and growth test were perfurmed to estimate <br />the chronic responses produced by the 7 hour Kerr Coal dischazge 002 on 19 ]anuary 1994. The <br />Ceriodaphnia test was run until 6090 of the convols released 3 broods of young and fathead minnow test <br />' was run for 7d. A copy of the Colorado CDPS WET chronic test repott form has been included for each <br />test. Please fill in the appropriate sections (e.g. ou[fall /f, iWC) before submitting. <br />Test procedures generally followed Colorado Department of Health guidelines (1993), with the <br />following exception. Since this outfall had a limited dischazge period, the "7-day" chronic test had to <br />be [ua with only one sample composited from the 7 hrs of dischazge. Renewals could not be colletted <br />J oa alternate days since there was no further dischazge. This modification of test conditions was approved <br />by the Colorado Department of Health following discussions with Kathy Kaliman. <br />The enclosed table summazizes the results of both tests. The fathead minnow chronic test indicated no <br />chronic toxicity. However, chronic effecu were observed at the 10090 vea[ment with Ceriodaphnia. An <br />NOEC (no observable effect concentration) of 7590 effluent was obtained, with an IC25 of 68`fo for the <br />sub-lethal biomass (number of young produced divided by number of females exposed) pazameter. LC50 <br />levels could not be determined for Ceriodaphnia or fathead minnows since significant mortality was not <br />observed in either chronic test. <br />!f you have any questions, please don't hesitate to call. <br />Sincerely, <br />CHAD K & ASSOCIATES, INC. <br />Steven P. Canto^ <br />Senior Vice President <br />SPC/ms <br />Enclosure <br />Pnmeo on <br />Recycietl Pap9r <br />