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NoNo <br /> CvvATC <br /> A S S O C I A T E S I N C <br /> petroleum hydrocarbons. Discoloration of the soil and a petroleum hydrocarbon odor were noted <br /> in the field. After the tanks were removed, the areas of the former tanks were backfilled. <br /> On November 14, 1997, a geologist from ATC Associates supervised the advancement of two <br /> soil borings to 30 feet below ground surface (bgs). Soil samples were collected at five-foot <br /> intervals and each soil sample was field screened with a Photoionization Detector (PID) for the <br /> presence of volatile organic compounds. Petroleum hydrocarbons were observed during field <br /> activities in borings SBI and SB2 beginning at depths of 24 feet and 19 feet bgs, respectively. <br /> Analytical results of soil samples indicated the presence of petroleum hydrocarbons. <br /> One groundwater sample was collected from each boring at the depth groundwater was first <br /> encountered, approximately 30 feet bgs. Groundwater samples were placed on ice and delivered <br /> under chain-of-custody documentation to State-certified AEN laboratory for chemical analysis. <br /> Groundwater samples indicated the presence of petroleum hydrocarbons. Field activities are <br /> summarized in ATC's Summary Report, Subsurface Investigation, dated January 14, 1998. <br /> On February 18, 1999, a geologist from ATC Associates supervised the installation of three <br /> groundwater monitoring wells from 39 to 41 feet bgs. Soil borings MWI, MW2, and MW3 were <br /> completed as two-inch monitoring wells. One soil sample from each boring was collected and <br /> after the groundwater monitoring wells were developed on groundwater sample was collected <br /> from each well. Soil and groundwater samples contained detectable concentrations of petroleum <br /> hydrocarbons. Results are summarized in ATC's Summary Report of Additional Subsurface <br /> Investigation, dated June 1, 1999. <br /> SCOPE OF WORK <br /> Plannine and Permits <br /> ATC has completed the soil boring permit application for the proposed subsurface investigation. <br /> The permit application and fee are attached to this workplan. ATC will also obtain the necessary <br /> encroachment permits from the City of Ripon. ATC will also schedule field personnel and <br /> equipment, notify Underground Service Alert to locate underground utilities as required, and <br /> perform any other necessary field preparation and job start-up activities. <br /> Advancement of Soil Borings <br /> Under this task, ATC will supervise the advancement of one soil boring employing cone <br /> penetrating testing (CPT) methods. Drilling will be conducted by State licensed Fisch <br /> Environmental (C57 #683865). The boring will be advanced near former borings SBI and SB2, <br /> the area of highest petroleum hydrocarbon concentrations, to evaluate the deeper subsurface <br /> conditions. A cone mounted with sensors at the tip will be advanced into the soil using direct <br /> push rods. The sensors will test the response of the soil to the force of the penetrating cone and <br /> this will allow the subsurface stratigraphy to be characterized. The boring will be advanced until a <br /> w:\14981\reports\wkp3.doc 2 <br />