SITE INFORMATION AND CORRESPONDENCE 1980-1999

Home Browse Search

WASTE DISCHARGE REQVREMENTS ORDER NO. 5-00- -6- CITY OF LODI WHITE SLOUGH WATER POLLUTION CONTROL PLANT SAN JOAQUIN COUNTY concentration is 0.050 µg/l (chronic criteria). The Sacramento-San Joaquin Delta has been listed as an impaired waterbody pursuant to Section 303(d) of the Clean Water Act because of mercury. This listing is based on elevated levels of mercury in fish tissue. Because the Delta has been listed as an impaired water body for mercury based on fish tissue impairment, the discharge must not cause or contribute to increased mercury levels in fish tissue. In view of the uncertainty of applicable water quality criteria and the accuracy of existing sampling results, this permit does not contain a water quality-based effluent limitation for mercury. This Order requires monitoring for mercury using `clean technique', for the purpose of establishing a performance-based effluent limitation, if it is determined to be necessary, and allows the Board to reopen the permit to add effluent limits for mercury. In the interim, the Discharger is required to develop a program for identification and control of mercury discharged within the collection system. 26. EPA's ambient water quality criteria for protection of aquatic life for a continuous concentration of lead is 3.6 µg/1 (30-day average, chronic criteria), based on a water hardness of 110 mg/l, and as converted to be expressed as total recoverable metal. Effluent monitoring for lead has shown the median concentration to be 1.5 µg/1, and the highest measured to be 10 µg/l, with 3 of 18 samples exceeding the converted chronic criteria. Five of the 18 samples had a relatively high reporting/detection limit of 5.0 µg/l. The Board finds that lead is or may be discharged at a level that will cause or have the reasonable potential to cause, or contribute to, an in-stream excursion above the Basin Plan narrative toxicity objective. A thirty-day average effluent limitation for lead is included in this Order,based on the converted chronic criteria. The Discharger is not currently capable of meeting this limit with the current treatment facilities. 27. Based on information submitted as part of the application, in studies, and as directed by monitoring and reporting programs, the Board finds that the discharge has a reasonable potential to cause or contribute to a violation of the Basin Plan narrative prohibition against the discharge of toxic substances in toxic concentrations with respect to chlorine. USEPA developed Ambient Water Quality Criteria for the Protection of Aquatic Life (Criteria) as recommended concentrations to protect against aquatic toxicity. This Order, and the Basin Plan,prohibits the discharge of toxic constituents in toxic amounts. Chlorine is used as a disinfectant at the wastewater treatment plant and,based on experience, has a reasonable potential to be discharged in toxic concentrations. The Criteria are well established and have undergone extensive testing and peer review. The Criteria are an appropriate measure of toxicity, and are the basis for establishing effluent limitations for chlorine. Because there is no significant dilution within Dredger Cut in the immediate vicinity of the discharge over the averaging period for acute toxicity water quality objectives, no mixing zone is designated for chlorine. 28. The Sacramento-San Joaquin Delta has been listed as an impaired waterbody pursuant to Section 303(d) of the Clean Water Act because of. (1) diazinon and chlorpyrifos (organophoshate pesticides), (2) aldrin, dieldrin, chlordane, endrin, heptachlor,heptachlor