COMPLIANCE INFO_1989-1996 - Laserfiche WebLink

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INFORMATION SHEET The City of Stockton proposes to discharge treated ground water from the T extraction of ground water polluted by leakage from the unlined Class III landfill . PolIuted 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 Littlejohns Creek tributary to the San Joaquin River. E Pumped ground water will be treated by passing it through an air stripper, then the stripped air serially passed through two exchangeable activated carbon units, and the water discharged to a holding tank prior to discharge to Littlejohns Creek. 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 Vg/1 ) for benzene, ethyl benzene, toluene, xylene, and other volatile organics in EPA Methods 601 & 602. 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 I 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 A constituents are present in the discharge and if so, what effluent limits are necessary for compliance with water quality objects. These waste discharge requirements will also function as the individual storm water permit. 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 (Pimeghales gromelas, Ceridaphnia dubia, Selenastrum capricornutum) 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, identifying the sources of the toxicity, and proposing a time schedule for eliminating toxicity. Once the absence of toxicity has been satisfactorily demonstrated, the Discharger shall commence compliance monitoring. Compliance monitoring shall consist of collecting quarterly samples and conducting chronic toxicity tests as specified in EPA 600/4-85/014. Only the most sensitive species