COMPLIANCE INFO_1991-1992 - Laserfiche WebLink

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INFORMATION SHEET CITY OF STOCKTON AUSTIN ROAD LANDFILL GROUND WATER TREATMENT SYSTEM AND STORM WATER DISCHARGE SAN JOAQUIN COUNTY 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 need continue to be tested during compliance monitoring, if clearly identified in previous testing. Twenty-four hour composite sampling for the chronic effluent toxicity monitoring is recommended for this discharge because no significant short-term variation is expected for this effluent discharge and this will reduce the number of tests required by the Discharger. If effluent toxicity monitoring data indicates little or no operational or seasonal variation exist in the effluent discharge, the Discharger may propose to change from composite sampling to grab sampling The Discharger proposes to sample two hours after the initial startup; once per day thereafter for four days; weekly thereafter for three weeks; and monthly thereafter. The proposed frequency of routine effluent monitoring is weekly for pH and specific conductivity, monthly for volatile organics, quarterly for Biological Oxygen Demand (BOD) and suspended solids, and annually for the ICAP metals scan. It is recommended that the Discharger install an automated sampling system for the treatment plant in order to facilitate collecting composite as well as grab samples. The purpose of this routine monitoring is to insure that the ground water treatment plant discharge does not adversely impact downstream biota in Littlejohns Creek. If routine monitoring show detectable concentrations of volatile organics, the frequency of monitoring will be increased to weekly until the constituent(s) concentrations are below detection. Monitoring for benzene, toluene, ethyl benzene, and xylene using EPA Method 602 is not required at this time because the treatment of landfill leachate or return condensate from the Pacific Energy power plant is prohibited. Past data from ground water monitoring does not indicate the past or recent discharges of the return condensate have impacted water quality beneath the landfill . If future monitoring finds that volatile organic compounds (VOCs), which exist in the return condensate, are present in ground water, then the monitoring program will be revised accordingly.