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Potential Effects of Contaminants on Fraser River Sockeye Salmon

Potential Effects of Contaminants on Fraser River Sockeye Salmon

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The CCME Water Quality Index (CCME WQI):CCME WQI =⎛⎜⎝2 2F +F +F121.73223⎞⎟⎠The divisor 1.732 normalizes the resultant values to a range between 0 and 100,where 0 represents the“worst” water quality and 100 represents the “best”waterquality.The CCME Water Quality Index calculati<strong>on</strong> produces an index that ranges between 0and 100. In additi<strong>on</strong>, the Water Quality Index can be classified categorically:• Excellent water quality (WQI: 95 - 100);• Good water quality (WQI: 80 - 94);• Fair water quality (65 - 79);• Marginal water quality (45 - 64); and,• Poor water quality (0 - 44).A4.3.3 Compilati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> Toxicity Screening Values for the Preliminary Evaluati<strong>on</strong><str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>C<strong>on</strong>taminants</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>Potential</str<strong>on</strong>g> C<strong>on</strong>cernToxicity Screening Values for Surface Water - A tiered approach was used to selecttoxicity screening values for surface-water chemistry data for the <strong>Fraser</strong> <strong>River</strong> Basin.Using this procedure, the lower <str<strong>on</strong>g>of</str<strong>on</strong>g> the Canadian water quality guidelines (CCME 1999)or the British Columbia approved and working water quality criteria (BCMOE 2010)was selected as the toxicity screening value for a chemical <str<strong>on</strong>g>of</str<strong>on</strong>g> potential c<strong>on</strong>cern. Bothtypes <str<strong>on</strong>g>of</str<strong>on</strong>g> benchmarks define the c<strong>on</strong>centrati<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g> these chemicals in water that wouldnot adversely affect any life stage <str<strong>on</strong>g>of</str<strong>on</strong>g> any aquatic species that are exposed for extendedtime periods. If such guidelines or criteria were not available for a substance, then thecriteri<strong>on</strong> c<strong>on</strong>tinuous c<strong>on</strong>centrati<strong>on</strong> promulgated by USEPA (2009) or a similar value(i.e., JWQB 1998) was selected as the toxicity screening value. For toxicity screeningvalues that are hardness, pH, or temperature dependent, data <strong>on</strong> the characteristics <str<strong>on</strong>g>of</str<strong>on</strong>g>each water sample were used to calculate a sample-specific toxicity screening valuefor that chemical <str<strong>on</strong>g>of</str<strong>on</strong>g> potential c<strong>on</strong>cern in water.Toxicity Screening Values for Sediment - Exposure to c<strong>on</strong>taminated sediments hasthe potential to adversely affect sockeye salm<strong>on</strong> during incubati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> eggs and alevins.A-37

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