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1.0 INTRODUCTION 1.1 Scope of Work This work plan has been prepared to address the remedial excavation and groundwater monitoring at Doane Products Company (DPC) facility at 450 E Granthne Road in Tracy? California as located on Figure 1 On April 29, 1991, DPC submitted a preliminary site investigation report prepared by Brunsing Associates, Inc (BAI) The report detailed the completion of the investigation phase of this project and proposed the remediation by e.ccavat.on In April 1990, Harlin Knoll of the San Joaquin County Public Health Services (SJCPHS) requested the submittal of a workplan detailing the remediation method Additionally, on July 23, 1991 the SJCPHS requested that the groundwater monitoring be instituted at the three wells on site. 1.2 Background/Site History On January 16, 1990, the Jim Thorpe Oil Company, a licensed tank removal company, removed the two 10,000 gallon diesel tanks and one 5,000 gallon gasoline tank from two separate excavations from the rear yard of the Tracy Faahty of DPC as shown in Figure 2. Sampling at the time of tank removal indicated the presence of petroleum hydrocarbons in one soil sample at a concentration of 53,000-ppm, Total Petroleum Hydrocarbons (TPH) as diesel in one location in the diesel underground storage tank (UST) excavation and nondetectable hydrocarbon concentrations at all others. The soil sample with the elevated hydrocarbon concentrations was located in the southwest corner of the excavation Analysis of seepwater in the excavation indicated hydrocarbon concentrations of 85 ppm of TPH as diesel The contractor partially refilled the tank excavations with soils from the clean end of the excavation and ceased all additional remediation The remaining 50 cubic yards (approximate) of soil from the excavation was stockpiled on site In February 1991, a preliminary sail and groundwater investigation was completed by BAI Soil hydrocarbons were found to exist within the backfilled soils in the excavation at up to 680 mg/kg Borings around the perimeter (B-1, P-1, and P-2) of the excavation indicated maximum concentrations of TPH as diesel of 16 mg/kg and Benzene, Toluene, Ethyl Benzene and Xylenes (BTEX) were not detected at concentrations over the reporting limits Groundwater samples from the monitoring well (MW-1) down gradient of the excavations indicated nondetectable concentrations of TPH as gasoline, TPH as diesel and BTEX A summary of all analytical results are included as Table 1 Based on those analytical results, the hydrocarbons are not expected to have migrated much farther than beyond the boundaries of the previous excavation 1 BRUNSING ASSOCIAI ES, INC ��