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Enviro-Chem Analytical, Inc. Acute Toxicity Testing <br />685 West Gunnison Avenue, Suite 108 West Elk Mine - April 2008 <br />Grand Junction, CO 81505 Outfall 001 2 Species <br />Introduction <br />At the request of West Elk Mining Inc. (WEM), Enviro-Chem Analytical, Inc. <br />conducted biomonitoring test to evaluate the toxicity of the West Elk Mine <br />Effluent. The test's purpose was to determine the effluent's LC50 for larval <br />fathead minnows (Pimephales promelas) and Daphnia magna during short-term <br />96-hour and 48-hour acute tests. <br />According to the NPDES permit, a acute test is failed whenever the LC50 is <br /><100%. <br />Methods <br />A two species chronic test was conducted according to the methods described in <br />the USEPA manual :Short-Term Methods for Measuring the Acute Toxicity of <br />Effluents and Receiving Water to Freshwater Organisms," 2002, Fourth Edition, <br />EPA/821-R-02-012, the TMI NPDES permit CO-0032115, and the Colorado <br />Department of Public Health and Environment Guidelines for Conducting Whole <br />Effluent Toxicity Tests". <br />Sample Collection <br />The effluent samples were collected by WEM personnel and hand-delivered to <br />the laboratory immediately. Upon arrival, each sample was logged in according <br />to the Sample Receipt procedures and initial chemistry values were obtained. <br />The sample was held on ice, 4 C or below, for use in renewing test chambers <br />Minimum chemistry included arrival temperature, pH, conductivity, dissolved <br />oxygen, ammonia, total residual chlorine, hardness and alkalinity. <br />Initial chemistry values are found in Table 1.