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APPENDICES <br />City of Redwood City, Public Works Division Initial Study & Mitigated Negative Declaration <br /> <br /> 11 Blankinship & Associates, Inc. <br /> <br /> <br />Mohapatra and Rengarajan 1997 <br />The acute toxicity of copper to wild-caught Liza parsia was evaluated. Liza parsia weighing between <br />15.0 to 30.0 grams (g) and measuring between 75.0 to 105.0 mm (approximately 3 to 4 inches) total <br />length were collected from the brackish water canals of Puduvypeen area in Cochin. The fish were <br />acclimatized to laboratory conditions for about one week at an approximate salinity of 9.8 ppt, <br />temperature of 28 °C, and total hardness of 2,956 ppm. Fish were aquatically exposed to copper <br />sulphate pentahydrate in 5 separate bioassays to determine the 12, 24, 48, 72, and 96 hour toxicity of <br />copper. The metallic copper LC50 estimated for the 12, 24, 48, 72, and 96 hour bioassays were 35.9, <br />34.9, 28.0, 22.0, and 21.8 mg/L, respectively. We selected the 96 hour LC50 of 21.8 mg/L, consistent <br />with acute endpoint selection recommendations (USEPA 2004). <br /> <br />To derive a TRV from the 96 hour LC50, a safety factor of 20 was applied. The resultant derived TRV <br />for the longfin smelt is estimated at 1.09 mg/L. It was estimated that applications of copper at the <br />maximum label rate of 1.0 mg/L metallic copper will not lead to aquatic exposure greater than or <br />equal to the derived aquatic TRV of 1.09 mg/L – calculated risk value is 0.917 (unitless). Thus, <br />copper-containing algaecides and/or aquatic herbicides applied to the Lagoon is not anticipated to <br />pose a risk to longfin smelt. <br /> <br />6.3.A. - Page 80