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Enviro-Chem Analytical, Inc. Acute Toxicity Testing <br />885 West Gunnison Avenue, Suite 108 Trapper Mining -May 2004 <br />Grand Junction, CO 81505 Outfall 020 2 Species <br />Study Summary <br />An effluent sample collected from the Trapper Mine Craig, Colorado was <br />evaluated for the presence of acute toxicity to larval fathead minnows <br />(Pimephales promelas) and Ceriodaphnia dubia during May 25-29, 2004. <br />Moderately hard reconstituted water (MHW) prepared according to USEPA <br />guidelines was used as the diluent for the toxicity tests. <br />The effluent tests met minimum control organism performance requirements <br />defined by the USEPA. <br />The table below summarizes the results of the effluent tests. <br />I Fathead Minnow Cerfodaphnia dubia <br />Test Endpoint (°~ Efluent) (96 Effluent) <br />i <br />i LC50 >100 ~ >100 <br />Organisms were purchased from Aquatic Biosystems located in Fort Collins, <br />Colorado. All reference toxicity test for both species were performed by them <br />and met minimum performance requirements defined by the USEPA and <br />produces IC25 values within the expected ranges. Organisms were or <br />acceptable quality and proper age upon arrival and beginning of test. <br />