Laserfiche WebLink
INTRODUCTION <br /> Biomonitoring provides an effective means to test multimedia effluents for <br /> toxicity. Detection of such effects solely through chemical analyses are often difficult <br /> to accomplish. <br /> The Colorado Water Quality Control Division requires certain dischargers holding <br /> NPDES permits to perform both acute and chronic biomonitoring tests as part of their <br /> permit requirements. The chronic tests measure significant differences in either <br /> reproduction (Ceriodaphnia) or growth (fathead minnows) between control and <br /> exposed organisms. These tests are conducted over 7 days as opposed to the 48 hr <br /> and 96 hr acute tests which measure mortalities. <br /> The present report discusses the results of a chronic biomonitoring test <br /> conducted on the effluent from Sunnyside's AT-004 mine effluent This test was <br /> conducted during September 1994. <br /> MATERIALS AND METHODS <br /> Sample Collection <br /> Grab samples of the plant discharge were collected in one-gallon containers on <br /> September 19, 21, and 23, 1994. Immediately after collection, samples were <br /> transported to the lab where they were refrigerated at 40C until use. Chain of custody <br /> forms showing sample transfer are included in Appendix 1. <br /> Dilution Water <br /> Reconstituted water prepared in the lab was used for a dilution water source In <br /> the tests. This water was prepared by mixing stock solutions of potassium chloride, <br /> sodium bicarbonate, and magnesium sulfate, and calcium sulfate powder with <br /> deionized water. <br /> Test Organisms <br /> The tests were conducted with Ceriodaphnia sp. and fathead minnows <br /> (Pimephales promelas). The Ceriodaphnia were cultured in Seacrest's laboratory. <br /> Stock cultures are grown in 3 1 glass beakers and/or aquaria. Brood females are <br /> cultured in individual plastic cups for a period of 14 days. Neonates born daily are <br /> removed from the brood chambers and used in tests. Brood and stock organisms are <br /> fed a mixture of digested trout chow, alfalfa, and yeast and an equal volume of algae <br /> daily. <br /> One day old fathead minnows cultured in the laboratory were used in the tests. <br /> The fish were obtained from eggs produced by adults in 10 gallon aquaria. Eggs were <br /> removed from the aquaria after fertilization and aerated until hatching. Normally, eggs <br /> hatch in 4-5 days. Fish were fed newly hatched brine shrimp daily. <br /> Test Procedures <br /> Upon receipt at the lab, the water sample was analyzed for ammonia, alkalinity, <br /> hardness, conductivity, dissolved oxygen, and pH. Ammonia was determined <br />