ARCHIVED REPORTS_2002_3 JTD - Laserfiche WebLink

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A monitoring system has been designed to test the soils to ensure the efficiency of hydrocarbon biodegradation. Soils in the LTUs will be sampled regularly to evaluate and manage the key treatment parameters such as soil moisture, soil pH, soil nutrient levels, and air temperature. Following treatment, the soil will be analyzed to determine if the petroleum hydrocarbon concentration meets the level acceptable for use as alternative cover or foundation material, or disposal. Each LTU will have a lysimeter at the low point for leak detection. The lysimeters monitor moisture in the vadose zone directly beneath the drainage system and are checked on a quarterly basis. These treatment units may also be used to treat other nonvolatile organics that are suitable for bioremediation such as PNAs. Treatment of Gasoline Contaminated Soil The "Preliminary Soil Remediation Work Plan, Gasoline Contaminated Soil, Forward Landfill Unit WMU G, Stockton, California" (Harding Lawson Associates, July 1991) describes the treatment system for gasoline contaminated soils. The specifications and reporting requirements of the treatment system are specified in the WDRs, Order No. R5-2003-0049 and in an October 31, 1990, letter from SJCPHS to Forward. Although Forward is not currently treating gasoline contaminated soil, these soils have been treated in the past and may be treated in the future. Gasoline- contaminated soils will be treated in WMU G-North or G-South by a vapor extraction and thermal oxidation technique in accordance with San Joaquin County Air Pollution Control District regulations on uncontrolled air emissions. The vacuum extraction (VE) treatment system will consist of treatment cells approximately 20 feet wide at the base by 200 feet long and 5 feet high. The volume of soil in each treatment cell will be approximately 550 cy. The base of each treatment cell will consist of compacted native soil covered by a 20-mil polyethylene liner. The stockpiled soil will be placed in 1-foot-thick lifts over the treatment cell liner to a height of approximately 5 feet. An air delivery system consisting of perforated PVC pipe will be installed in each treatment cell to aid in removing residual volatile organic chemical concentrations present in the soil. A 4-inch pipe will be placed at the bottom of the treatment cell with a set of three pipes placed at the top. The Forward Landfill JTD 6-15 J:\Allied\Forward\JTD Amendment\January 2007 JTD Amendment\JTD Sec 6 Final.doc: 5/22/02;Rev. 1:7/2002:Rev.2:4/2003;Rev 3:6/2003;Amendment No. 1:2/1/2007 BRYAN A.STIRRAT 6 ASSOCIATES