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WASTE DISCHARGE REQ NTS -4- FOR CITY OF STOCKTON AUSTIN ROAD LANDFILL FACILITY CLASS M LANDFILL SAN JOAQUIN COUNTY 24. The Discharger has implemented a periodic load checking program which consists of daily random checks of incoming loads. Signs, pre -notification programs, and procedures for handling identified hazardous wastes have also been developed. Solid Waste Assessment Test and Verification Monitoring Plan, dated June 1989 found significant water quality impacts at downgradient ground water monitoring wells MW- I and MW -4. Volatile organic compounds (VOCs) were found in the downgradient wells. Supplemental sampling results indicated that VOCs were detected in California Youth Authority (CYA) wells CYA- I and CYA-2 at levels equal to or slightly above action levels, in a state agricultural well on the west side of Austin Road, and in a private well at 8106A Austin Road. However, confirmation sampling results did not detect any VOCs at either of the CYA wells. Sampling at the private well at 8106A Austin Road detected VOCs. The Discharger constructed and sampled monitoring well MW -14 which did not encounter VOLs. Further investigation is needed to determine whether the pollutants in the well at 8106A Austin Road are related to the landfill plume. 26. An evaluation monitoring program was implemented in three phases to determine the vertical and horizontal extent of contamination. Phases I and 11 confirmed VOC impact along the entire downgradient edge of the landfill and in the first encountered water bearing zone. In April 199 1, Phase Ell indicated the chlorinated hydrocarbon impacted ground water extends laterally as far as 1,000 feet downgradient of the edge of the landfill. 27. A Corrective Action Plan, dated 29 August 199 1, was submitted by the Discharger. Thi plan describes and involves the following actions: a. reduction of leaching of chlorinated hydrocarbons into the ground water by checking incoming loads into the landfill for hazardous materials and implementing measures to reduce storm -water infiltration into the refuse; b. extraction of ground water from the two wells to reduce the off-site migration chlorinated hydrocarbons; I c. installation of a system for treating the extracted ground water prior to discharge; and d. monitoring the effectiveness of the corrective action and determination of the need• modifications. Two ground water extraction wells with a combined design capacity of 303 gallons per minute (gpm) have been installed to extract polluted ground water. VOCs are stripped