2008-02-04_HYDROLOGY - C1980007 - Laserfiche WebLink

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.' Enviro-Chem Analytical, Inc. 685 West Gunnison Avenue, Suite 108 Grand Junction, CO 81505 Outfall 017 2 Species Sample Collection ~ Sample Acute Toxicity Testing West Elk Mine -October 2007 Sample Volume 10/22/07 10:30 am ~ Test Initiation and Renewal ~ 6.0 gallons Sample preparation followed test guidelines outlined by the USEPA. Test Performance Effluent concentrations of 100%, 50%, 25%, 13% and 6.5% were utilized during the tests. Concentrations at less than 100% were obtained by diluting the effluent samples with MHW for the fathead minnow test and the Hard water for the Daphnia magna test in the laboratory. All volume measurements were made using graduated cylinders of minimum size. Test temperature for both species was maintained at 20 +/- 1 C. Initial chemistry measurements of pH, dissolved oxygen, temperature and conductivity were performed for each effluent test concentration. Additionally, alkalinity and hardness were performed for the MHW and 100% effluent sample. Final chemistry measurements included temperature, pH, and dissolved oxygen for each concentration and MHW control sample at the end of each renewal period. Fathead Minnows - Four replicates per exposure concentration were tested with 10 organisms per test chamber. Organisms were obtained from Aquatic Biosystems Inc. Fort Collins, Colorado and were 9 days old at test initiation. Fish were impartially distributed to each test chamber.Test chamber consisted of 500 mL disposable plastic cups containing 250 mL of test solution. Fathead minnows were fed once daily, 0.15 mL 2 hours prior to water renewal, newly hatched brine shrimp (Artemis). Brine shrimp cysts were obtained from Aquatic Biosystems Inc, Fort Collins, Colorado and were hatched in salt water overnight. Brine shrimp were thoroughly rinsed prior to feeding to remove any residual salt. Test solution was 3 renewed daily at approximately 24-hour intervals from the original initiation time of the test.