COMPLIANCE INFO_1991-1992 - Laserfiche WebLink

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INFORMATION SHEET The City of Stockton proposes to discharge treated ground water from the extraction of ground water polluted by leakage from the unlined Class III landfill . Pol1uted ground water has been detected 1000 feet downgradi ent to the northeast of the landfill . The ground water treatment system is designed to treat 400 gpm (580,000 gpd) of extracted ground water. About 305 gpm (440,000 gpd) will be discharged to the north branch of the south fork of Littlejohns Creek tributary to the San Joaquin River. The north branch of the south fork of Littlejohns Creek is an intermittent stream maintained by the San Joaquin County Flood Control District primarily for the drainage of irrigation return flow. Pumped ground water will be treated by passing it through an air stripper, and the water discharged to a manhole prior to discharge to Littlejohns Creek. The stripped air is serially passed through two exchangeable activated carbon units. The activated carbon units are regenerated or disposed off-site. The proposed treatment system should be capable of dependably removing volatile organic constituents to non-detectable concentrations as determined by current analytical technology. The 30-day median effluent limitations have, therefore, been set to less-than the limit of detection (0.5 t&g/1) for 1,1 Dichloroethane, 1,2 Dichloroethane, Vinyl Chloride, Tetrachloroethene, and other volatile organics in EPA Methods 601. The Daily Maximum effluent concentrations are established to allow for some effluent quality variation and the false positive analytical results inherent in analyses near the limits of detection. For volatile organics, the Daily Maximum Effluent Limitation has been set at ten times the detection limit. Water quality objectives adopted pursuant to the Inland Surface Waters Plan are applicable to the discharge. The Discharger has not sampled for all substances in Table 1 and 2 of the Inland Surface Waters Plans (91-12-WQ); however, the Discharger will be required to conduct a study to determine whether regulated constituents are present in the discharge and if so, what effluent limits are necessary for compliance with water quality objectives. These waste discharge requirements will also function as the individual storm water permit for the proposed ground water treatment system and the entire Austin Road Class III Sanitary Landfill . This permit requires the Discharger to take steps necessary to reduce or eliminate industrial storm water pollution. The Discharger is also required to submit a Storm Water Pollution Prevention Plan to prevent contaminants in the runoff from adversely affecting water quality. Chronic effluent toxicity monitoring will be required since the discharge will constitute at least fifty percent of the flow in the receiving water. The proposed chronic effluent toxicity monitoring should consist of chronic toxicity tests employing three species (PimephalesRromglis, Ceriodgphnia dubia, SelenastruM gARriggr_BMIUM) as specified in EPA 600/4-89/001 (March 1989) "Short- Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms". If the chronic toxicity testing results indicates that the Discharger may be contributing toxicity to Littlejohns Creek, the Discharger shall submit a Technical Report containing and analyzing the results of the toxicity testing,