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NX�MA Working To Restore Nature On November 22, 1989, six composite soil samples were collected from the excavated material stockpiled on-site Laboratory results for composite samples collected from the excavated material did not indicate the presence of hydrocarbon contamination above method detection levels Based on analytical results, the former tank pit was backfilled with the excavated remediated material To assess the potential impact of hydrocarbons on groundwater beneath the site, four groundwater monitoring wells (MW1, MW2, MW3 and MW4) were installed at the site by WaterWork Corp (August 1990 and March 1992) Monitoring well locations are shown on Figure 2 Soil samples collected from the capillary fringe zone in each well contained non- detectable concentrations of gasoline hydrocarbons Analyses of groundwater samples collected from the site monitoring wells indicate that groundwater contamination beneath the site is limited to a relatively small area in the immediate vicinity of the former tanks The groundwater flow has been consistently determined to be in the eastern direction At the request of San Joaquin County Public Health Services, Environmental Health Division (PHS/EHD), RESNA Industries Inc (RESNA) submitted a Problem Assessment Report and Soil Contamination Workplan dated May 1993 Soil excavation was determined to be the preferred soil remediation method for the site FIELD ACTIVITIES The following scope of work was based upon the information collected during previous site investigations The work was designed to remove the remaining impacted soil in the vicinity of the former tanks All field work was performed under the supervision of RESNA personnel in accordance with the Quality Assurance/Quality Control Plan (QA/QC) and the site specific Health and Safety Plan on file with PHS/EHD Soil Excavation and Sampling On November 8 through 12, 1993, approximately 1,500 cubic yards of soil were excavated from the vicinity of the former underground fuel storage tanks The extent of the excavation is depicted on Figure 3 Excavation was conducted by Goins Environmental Construction (Lic #674281) under the direct supervision of a RESNA geologist Excavation activities were performed under the regulatory guidance of Ms Margaret Lagono of PHS/EHD A photoionizahon detector (PID) calibrated to an isobutylene standard and visual and olfactory observations were utilized dunng excavation to assist in evaluating the lateral and vertical extent of soil impaction PID readings ranging from 0 to 500 ppm and petroleum hydrocarbon odors were noted between approximately 4 and 17 feet below grade Excavation continued until field evidence indicated that contamination was no longer present I500591SXR-0194 FNL 2