SITE INFORMATION AND CORRESPONDENCE

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WORK PLAN FOR PROPERTY ACQUISITION/TRANSFER ASSESSMENT MODESTO TALLOW COMPANY STOCKTON FACILITY STOCKTON,CALIFORNIA 1.0 INTRODUCTION This Work Plan presents the approach to perform an environmental assessment at the Modesto Tallow Company's Stocton facility and has been prepared as part of the Environmental Assessment Review Process for the San Joaquin County,Public Health Services,Environmental Health Division (PHS-EHD). Work will be supervised by Heritage Environmental Services of Sacramento, California and is being conducted as part of a property acquisition/transfer assessment. The site is located at 4221 East Mariposa Road in Stockton, California. The nearest cross street is Munford Road. The site consists of a rendering facility for the manufacturing of tallow. The attached figure presents a plot plan of the site and identifies the location of several operations known to exist that could impact either soil or groundwater beneath the site. The objective of this environmental assessment is to evaluate the potential presence of impacts to soil and/or groundwater beneath the site prior to potential purchase of the property. The approach developed to meet this objective includes the completion of a screening level soil vapor survey and in situ groundwater sampling program. The remainder of this Work Plan presents the procedures that will be used to conduct the soil vapor survey(Section 2.0),in situ groundwater sampling(Section 3.0),and an outline of the report that will be submitted to the PHS-EHD following completion of the field investigation(Section 4.0). 2.0 SOIL VAPOR SURVEY The soil vapor survey will be conducted to obtain screening information concerning the potential presence of impacts to soil beneath the site resulting from previous operations of the facility. At this time, it is anticipated that approximately 20 soil vapor points,designated SVS-1 through SVS-20,will be completed. Proposed locations are shown on the attached figure. The majority of proposed soil vapor points are located in areas of known facilities such as fueling areas and process areas. It should be noted that the location and number of points may be altered in the field based on the results of initial soil vapor points. At each location, soil vapor samples will be collected at 5 feet and 15 feet below ground surface by driving a reusable 1-inch-diameter stainless steel probe with a retractable tip into the ground to the desired depth. Probes are driven with a hydraulic press or hydraulic hammer and consist of 4 and 2 foot lengths fitted with detachable drive tips. After reaching the desired sampling depth,a length of disposable nylaflow tubing is lowered down the inside of the probe and threaded to the drive tip. The vapor s4mple is collected by attaching a graduatedsyringe tolhelud of the nylaflow tubing. Three dead volumes are purged through the syringe prior to collection of the actual sample. The samples will then be immediately analyzed with a mobile laboratory. The analysis will include total petroleum hydrocarbons (TPJ-I)and benzene,toluene,ethylbenzene,and xylenes(BTE}i). In addition,each sample will be screened by the mobile laboratory for the presence of halogenated volatile organic compounds(HVOCs). If HVOCs are identified during this screening process,they may be added to the analyte list for additional soil vapor samples. After collection of the second soil vapor sample,the probe will be removed from the hole and the probe hole will be backfilled to the surface using#8 granulated bentonite. The soil vapor survey will be conducted by Transglobal Environmental Geochemistry(TEG)of Sacramento, California under the supervision of a California registered geologist from Heritage Environmental Services.