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Client: Colowyo Coal Company C00045161 SCG Project No.: 419340.B <br /> Site: 010A Outfall <br /> Test Procedures <br /> Upon receipt at the lab, samples are analyzed for alkalinity, hardness, conductivity, <br /> dissolved oxygen, arnmonia, chlorine, and pH. Alkalinity and hardness are determined <br /> titrimetrically according to methods described in Hach Chemical Company]. Ammonia is <br /> measured by a Thermo Orion ion-selective electrode according to the procedures in <br /> 2 <br /> APHA/AWWA/WEF . Conductivity, dissolved oxygen, and pH probes were used to take these <br /> measurements. <br /> The test followed the procedures in EPA' and CDPH' guidelines. Exposure <br /> concentrations included control (0%), 20%, 40%, 60%, 80%, and 100% mixtures', diluted with <br /> moderately hard laboratory reconstituted water. <br /> Individual Ceriodaphnia is were placed in So plastic containers containing <br /> approximately 15ml of exposure medium. Ten replicates at each concentration were used. The <br /> animals were fed daily with the YCT mixture and an equal volume of the green algae <br /> (Sete nastrurn capricornittum). The exposure medium was changed daily in each container and <br /> the number of young released overnight were counted and recorded. Young were -removed from <br /> the containers daily and discarded. Routine measurements were made each day of temperature, <br /> dissolved oxygen, and pF1 before and after the water changes. <br /> Fathead minnow were exposed in 500ml plastic cups to which 250ml of media was added <br /> and replaced daily. Four replicates were used at each concentration. Ten fish, less than 24-hours <br /> old, were placed in each cup. The fish were monitored daily for survival and fed live Brine <br /> shrimp at least twice per day. After seven days, the fish were removed from the cups, <br /> euthanized,, and then placed in aluminum pans and dried in an oven for a minimum of six hours <br /> at I OO'C. The pans were then weighed on a five-place analytical balance to determine the <br /> average dry weight of the fish from each replicate. <br /> Dam Ana ysis <br /> Data from the test(s) were analyzed on a personal computer using the TOXCALC <br /> package developed by Tidepool Scientific Software. Statistical tests used in the analyses are <br /> shown in Table 1. Test acceptability was determined using control survival and performance <br /> criteria., concentration-response relationships, and percent minimum significant differences <br /> (USEPA 5'6). <br /> SeaCrest Group 6 <br />