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OV %Tt JUL 2 1 2000 ENVIRONMENT HEALTH PERMIT/SERVICES California, dated July 11, 2000. This workplan was approved by San Joaquin County Public Health Services Environmental Health Division (PHS/EHD) with minor modifications on July 14, 2000. Drvwell Destruction The drywell locations are shown on Figure 2 in the bottom of a pond area. The depth of the pond area is approximately four feet below ground surface (bgs). The drywells were approximately 30 inches in diameter and 38 feet deep. In each drywell was a 4-inch PVC center pipe. A small ramp was constructed in the southwest corner of the pond area to provide access for the equipment necessary to complete the drywell destruction. The well monuments were removed from the top of each well. A vacuum rig was used to remove gravel from around the center pipe of each drywell. Water was injected into each drywell to loosen up the gravel pack. The gravel and water were then removed from the drywells using the vacuum rig. Gravel encountered in each well was approximately 2.5 inches in diameter, which is larger than the 1.5-inch diameter gravel usually encountered in most drywells. Near each drywell, a shallow pit was excavated and lined with visquene plastic. The gravel, injection water, and soil cuttings from each drywell was placed in these pits and one composite soil sample was collected from each spoils pile. After removing as much gravel as possible with the vacuum rig from each drywell, the bucket auger rig was then used to overdrill each drywell to the bottom of the original boring, approximately 38 feet bgs. Once the bottom of each drywell had been verified, another two feet of soil was removed from each drywell and a soil sample was collected from the bottom of each drywell. Soil cuttings were placed in the dedicated pits described above. Soil Sample Anal In accordance with the PHS/EHD Guidelines for Closure of Shallow Dry Wells, all eight samples (four bottom samples and four cuttings samples) were analyzed for volatile organic chemicals (VOCs) by EPA method 8260, semi-volatile organic compounds (SVOCs) by EPA Method 8270, total petroleum hydrocarbons as gasoline (TPHg) and as diesel (TPHd) by EPA method 8015, total oil and grease (TOG) by method 5520, and for toxicity characteristics of metals CAM 17 by TCLP analysis. State-Certified Excelchem Environmental Labs analyzed all eight soil samples on a 24-hour turn-around time. Soil samples collected from the bottom of the drywells NW, SW, SE, and NE contained no detectable concentrations of VOCs, SVOCs, TPHg, TPHd, or TOG. The soil samples collected from the bottom of the drywells NW, SW, SE, and NE contained low concentrations of various metals. The concentrations of metals detected in these soil samples were consistent with