FIELD DOCUMENTS_1992-1999 - Laserfiche WebLink

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WASTE DISCHARGE REQUIREMENTS -5- MARLEY COOLING TOWER COMPANY SAN JOAQUIN COUNTY the Discharger needs to conduct a Toxicity Reduction Evaluation (TIE) to determine the cause and develop a corrective action plan. 20. The Discharger has had repeated violations of Effluent Limitation 1 in Order No. 88-124 for chromium, capper and TDS. The Discharger was notified of the violations by letter dated 30 September 1991. Operational changes were implemented to prevent future violations. Due to the complexity of the treatment plant it is critical that operations be maintained by adequately trained personnel . 21 . The Environmental Protection Agency (EPA) and the Board have classified this discharge as a minor discharge. 22. The beneficial uses of the Calaveras River, Upper Mormon Slough, and the Stockton Diverting Canal are municipal and domestic, industrial , and agricultural supply; recreation; aesthetic enjoyment; navigation; ground water recharge, fresh water replenishment; and preservation and enhancement of fish, wildlife and other aquatic resources. 23. The beneficial uses of the underlying ground water are municipal and domestic, industrial , and agricultural supply. 24. The aquatic standard of 11 pg/l for hexavalent chromium represents the most significant limitation to operation of the water treatment plant. Water within the treatment plant which contains hexavalent chromium exceeding specific set points for in-line meters will prompt automatic shut down or recycle modes. The system design requires optimum performance to achieve this effluent limit. Bench tests have indicated that the electrochemical process is effective in reducing high concentrations of chromium to meet the 11 pg/1 chromium effluent limit only after filtration of the effluent. The bench tests also indicated that the TDS concentrations of the electrochemically treated ground water should be the same as the influent or lower. Arsenic in the ground water taken from the intermediate wells is virtually nonexistent and copper has rarely been measured at concentrations exceeding 6.5 pg/l . 25. On 11 April 1991 the State Water Resources Control Board (SWRCB) adopted the California Inland Surface Water Plan (Plan) . On 19 November 1992 the SWRCB adopted amendments to the Plan. These requirements are consistent with that Plan. 26. The Board has considered antidegradation pursuant to 40 CFR 131. 12 and State Water Resources Control Board Resolution 68-16 and finds that the permitted discharge is consistent with those provisions. This Order provides for an increase in the volume and mass of pollutants discharged. There is no evidence to indicate that the increase in discharge will cause significant impacts on aquatic life, which is the beneficial use most likely affected by the pollutants discharged. The increase in the discharge allows maximum