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Saw �..J <br /> 1117 Lone Palm Avenue, Suite B <br /> Cv <br /> Modesto, CA 95351 <br /> www.atcassociates,com vATC <br /> 209-579-2221 <br /> ASSOCI ATE S I N C . Fax 209-579-2225 <br /> Environmental,Geotechnical and Materials Engineers <br /> In May 2003, GHH Engineering, Inc. (GHH) supervised the advancement of three soil borings, SB2, SB3, <br /> and S134, at the locations shown on Figure 2. Soil samples from SB3 and SB4 contained detectable <br /> concentrations of MTBE, and soil samples from SB3 also contained detectable concentrations of benzene, <br /> ethyibenzene, and xylenes. Groundwater samples collected from SB3 and SB4 contained detectable <br /> concentrations of TPHg, total petroleum hydrocarbons as diesel (TPHd), and MTBE. The groundwater <br /> sample from S133 also contained detectable concentrations of benzene, ethyibenzene, and xylenes. <br /> In January 2004, ATC personnel advanced three borings at the site to depths of approximately 65 feet bgs. <br /> The borings were completed as monitoring wells MW1, MW2, and MW3. Petroleum hydrocarbons were <br /> not detected in soil samples collected from the borings or in groundwater samples collected from MWI, <br /> MW2, and MW3. Field activities and analytical results are detailed in ATC's Summary Report of <br /> Subsurface Investigation, dated June 24, 2004. <br /> SCOPE OF WORK <br /> Planning and Permits <br /> v , <br /> ATC has prepared the drilling permit applications for the proposed subsurface investigation. The permits <br /> and associated fees are attached. ATC will also schedule field personnel and equipment, notify <br /> Underground Services Alert to locate underground utilities as required, and perform other necessary field <br /> preparation and job start-up activities. <br /> Drillingof Soil Borings <br /> This phase will include drilling seven soil borings to a depth of approximately 60 feet bgs and one soil <br /> boring to a depth of 50 feet bgs at the locations shown on Figure 2. The borings will be drilled by a State <br /> C57-licensed drilling company utilizing hollow-stem auger drilling methods. Two soil borings will be <br /> advanced to 60 feet bgs northwest and southeast of the current fuel dispenser islands to further define the <br /> extent of contamination previously identified in soil samples collected from Bl, SB3, and SB4. One soil <br /> boring will be advanced adjacent to MW2 to a depth of 50 feet bgs to provide data from depths above 50 <br /> feet bgs. Soil samples were previously collected from the borehole of MW2 at depths of 55, 60, and 65 feet <br /> bgs. Five soil borings will be advanced to 60 feet bgs in the southeastern portion of the site in the vicinity of <br /> the former locations of the fuel dispenser islands to eliminate data gaps in this area. <br /> A field geologist will be present to log drill cuttings and soil samples. Descriptions of soil types <br /> encountered and sample collection intervals will be recorded on boring logs. Soil samples will be collected <br /> at five-foot intervals using a California-modified split-sppon and field screened with a photo ionization <br /> detector (PID) for volatile organic compounds (VOCs). Soil cuttings generated from drilling activities will <br /> be stored on site in 55-gallon drums. <br /> Sample Analyses <br /> Selected soil samples will be immediately placed on ice and delivered under chain-of-custody <br /> documentation to a State-certified laboratory for analyses. Samples will be analyzed for TPHg by EPA <br /> Method 8015M and BTEX and fuel oxygenates by EPA Method 8260B. <br /> 0148854orkp1ans\wkp1n2005-add.doc 2 <br />