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1 <br /> �! Mr. Michael Kith <br /> July 20, 2000 <br /> Page 2 <br /> SCOPE OF WORK <br /> Ground Zero will ';supervise the drilling and sampling of five soil borings. One boring will be located <br /> within the former'Aank pit, and four borings will be located along the perimeter of the former tank <br /> pit. The locations of the proposed borings are shown on Figure 2. A C57 licensed drilling company <br /> will advance the borings using a truck mounted Geoprobe 5400 direct push rig. Soil samples will be <br /> collected at 5-foot depth intervals for the field screening (odors, discolorations FID readings) and <br /> stratigraphic descriptions. Samples will be collected using a 1 3/4-inch diameter core sampler-lined <br /> with clear acetatel sleeves. The portion of the sample to be analyzed will be immediately capped and <br /> preserved at a temperature of approximately 4° Centigrade. No cuttings requiring disposal will be <br /> produced using the direct push drilling method. Borings will be backfilled to the ground surface with <br /> neat cement grout. <br /> At minimum five 6 soil samples will be analyzed from the central boring, and three samples will be <br /> analyzed from each peripheral boring. The samples will be submitted for the analysis of,total <br /> petroleum hydrocarbons as gasoline (TPHg) using EPA method 8015 modified; total oil and grease <br /> (TOG) using method 418.1 or 5520; benzene, toluene, ethylbenzene, xylenes (BTEX) using EPA <br /> method 8020; and volatile organic compounds (VOC's) including gasoline oxygenate additives using <br /> EPA method 8260. Selection of soil samples for laboratory analysis will be based on field evidence <br /> of petroleum hydrocarbon contamination such as discoloration, odors, and FID readings, as well as <br /> significant lithologic changes. <br /> One groundwater sample will also be collected and analyzed for the constituents listed above_. The <br /> sample will be collected by driving the sampler to the desired depth and exposing the screen to the <br /> formation. The groundwater sample will be collected using a length of 0.17 inner diameter Teflon <br /> tubing equipped with a stainless steel bottom check valve. The tubing will be inserted into the probe <br /> rods and pushed to the bottom of the sampler to the desired depth. The groundwater sample will be <br /> brought to the surface by creating a positive displacement effect, thereby forcing the water sample to <br /> the surface where it will be collected directly into the appropriate sample containers. All analysis will <br /> be performed by a California State certified laboratory. <br /> All sampling and'! drilling equipment will be washed thoroughly with laboratory-grade detergent and <br /> water between uses to minimize the potential of cross contamination. Wastewater generated from <br /> decontamination iactivities will be placed into DOT approved containers and stored on site pending <br /> waste disposition options. <br /> All site activities shall be in accordance with the site health and safety plan (Attachment A) and <br /> QA/QC plan (Attachment B). <br /> A technical report describing field activities, analytical results, conclusions and recommendations will be <br /> submitted to North Stockton Auto Service, San Joaquin County PHS/EHD and the California Regional <br /> Water Quality Control Board(CRWQCB). <br /> A completed drilling permit application and associated fees will be submitted under separate cover <br /> upon approval of this workplan. <br /> i <br />