COMPLIANCE INFO_1989-1996 - Laserfiche WebLink

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INFORMATION SHEET CITY OF STOCKTON AUSTIN ROAD LANDFILL FACILITY CLASS III LANDFILL SAN JOAQUIN COUNTY The City of Stockton presently owns and operates a Class III landfill in Section 3, TIS, R7E, MDB&M. This is approximately six miles southeast of Stockton, on Austin Road. The site consists of approximately 135 acres. Operations began around 1955. The landfill accepts municipal solid waste from the City of Stockton. The site is currently accepting approximately 700,000 cubic yards (200,000 tons) per year from commercial haulers in the City of Stockton. The City has accepted, on a one-time basis, approximately 20,000 cubic yards of digested sewage sludge from the City' s wastewater treatment plant in 1989, and will accept approximately 5,000 cubic yards of this sludge on a yearly basis. The sludge is currently being stockpiled at the landfill . The sludge may be used in the foundation layer of the final cover. The first water bearing formation is approximately 70 feet below the base of the landfill , with the hydraulic gradient to the north/northeast. The beneficial uses of groundwater are domestic, municipal , and agricultural . The facility receives an average of 14 inches of precipitation per year, with the 100-year, 24-hour precipitation event of 6.17 inches. Pacific Energy Inc. operates a methane gas recovery system under contract with the City of Stockton. The methane is used in a power plant to generate electricity. The gas recovery system has an estimated life of 15 to 20 years. Condensate from the system is returned to Austin Road Landfill via a leach line placed at the upper trash/fill interface. A Solid Waste Assessment Test was performed at the facility as required by Water Code Section 13273. The results of the test show that there has been a significant water quality impact to the ground water. Volatile organic compounds (VOC's) were found in the downgradient monitoring wells. This was confirmed with further sampling. Supplemental sampling results indicated that VOC's were detected in California Youth Authority (CYA) wells CYA-1 and CYA-2 at levels equal to or slightly above action levels. However, confirmation sampling of the CYA wells did not detect any VOC's. Sampling at a private well at 8106A Austin Road did find VOC's, and this was confirmed by further sampling. Because of the detection of volatile organics in the ground water down gradient of the landfill , an evaluation monitoring program was implemented to determine the nature and extent of the release. The initial investigation included soil borings and ground water quality testing along the upgradient and downgradient edges of the landfill . The results of the borings along the downgradient edge of the landfill showed that the water quality in the upper two water zones has been impacted. It was determined that