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Mountain Coal Company CO - 0038766 SCG Project No.: 304225 <br />Site: West Elk Mine <br />RESULTS <br />The data sheets for the acute tests are located in Appendix 2. Table 1 summarizes the <br />results of Daphnia magna tests with the treated and untreated effluent. <br />Table I. Daphnia magna survival and LC50 calculations for treated and untreated effluent. <br />'=a, ' ",,.~ ~"" ~„`~ ~~' '+~~~ ` '"`SU RVIVAL TOTALS (outt'of520) "..#'~4 ~~ <br />,~ <br />M a~a''~ <br />~ <br />~ . <br />-~ <br />>r ~ ~ <br />~ <br />~ ~` ~~ x ~' ~ <br />, <br />~ ~- <br />Concentration% <br />h h <br />, <br />~ <br />, <br />. <br />n <br />~~;~ ~~ <br />~ ~~ 3, <br />" ~ ~~~ ~ "Treatedeffluents~ - ~: <br />~~ ~ ~ <br />~(Efffuent)~' <br />~ ~ <br />~ <br />Untreated Ettluent <br />=~ " <br />" ~ ~~~~ 50% <br />~ ~ ;25% <br />'~2~.5% <br />_` <br /> , <br />~~~ <br />~ .~ <br />." <br />~ _ ~Q, <br />_~ <br />t <br />100 1 5 1 0 <br />50 14 17 14 19 <br />25 17 12 18 20 <br />12.5 16 11 19 18 <br />1.9 20 12 17 20 <br />Control 20 20 20 20 <br />' ~b~~LC50~y~s~-""~ <br />r 60 <br />5% 75 <br />6% 60 <br />5% 67 <br />6% <br />, . . . . <br />r.~- ~ ~ w <br />" "' <br />1 <br />'95% Llmit y <br />" <br />~'= <br />25 - 100 <br />25 -100 <br />25 - 100 <br />50 - 100 <br />, <br />: <br />+ <br />., <br />Survival in the Fathead minnow test was 100% at every effluent concentration. Control <br />survival was 100%. <br />DISCUSSION <br />The sample collection showed the effects of toxicity to Daphnia magna in both the <br />treated and untreated effluent samples. The discharge fails WET (whole effluent toxicity) test <br />guidelines for this sampling period. <br />The sample did not show toxicity in the Fathead minnow test. The sample passes WET <br />requirements for this species. <br />The results appeaz to confirm that TDS (mainly in the form of high alkalinity) continues <br />to be the only source of toxicity in the sample. <br />REFERENCES <br />1. Hach Chemical Company. 2002. Hach Water Analysis Handbook. Hach Chemical <br />Company. Loveland, Colorado. 1260 pp. <br />2. APHA/AWWA/WEF. 1998. Standard Methods for the Examination of Water and <br />Wastewater. 20`" Edition. American Public Health Association. <br />3. USEPA 2002. Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters <br />to Freshwater and Marine Organisms. EPA-821-R-02-012. <br />4. Colorado Department of Public Health and Environment (CDPHE). 1998. Laboratory <br />Guidelines for Conducting Whole Effluent Toxicity Tests. Water Quality Control Division. <br />The SeaCrest Group 7 <br />