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i <br /> 'J <br /> r <br /> McLaren Environmental Engineering performed l.a site utility clearance <br /> during the initial site visit and no additionah underground utilities were <br /> found in the vicinity of the former tanks. <br /> r PROPOSED SITE ASSESSMENT WORK <br /> I. <br /> The objective of the Stockton Ford New Holland"i{site assessment work is to <br /> preliminarily define, to the extent possible,!1 the lateral and vertical <br /> extent of contamination in soil and groundwater associated with leakage <br /> from the former tanks. is <br /> 'i <br /> The approach taken to achieve this will be to:'!1 <br /> I,j { <br /> Drill and sample one soil boring adjacent to the north edge of <br /> the excavation and convert this boring! to a monitor well. Based <br /> on information obtained during the initial site visit, this is <br /> expected to be downgradient from the excavation. <br /> Drill and sample three soil borings, approximately 30 feet from <br /> the excavation, one upgradient (south-southwest) and two <br /> downgradient (northeast and north) ,, based on the estimated <br /> direction of groundwater flow. Ifl; during drilling, field <br /> observations indicate that no soil contamination is present, these <br /> borings will be converted to monitor wells. <br /> If field observations indicate soil contamination, each boring <br /> will be backgrouted and an additional "step-out" soil boring <br /> drilled approximately 30 feet further '�from the excavation. Once <br /> the extent of contamination is determined by this approach, the <br /> apparently clean soil borings will be converted to monitor wells. <br /> Figure 3 shows the proposed locations of Initial soil borings and - <br /> secondary (step-out) soil borings, i. <br /> i <br /> The borings will be drilled -to a depth of approximately 15 feet, using a <br /> continuous-flight hollow stem auger drill ri'g. A California modified <br /> split-spoon sampler containing brass liners will be used for collecting <br /> soil samples for laboratory analysis. Samples'Iwill be collected at three <br /> to five-foot depth intervals, depending on site conditions. A field ; <br /> organic vapor analyzer will be used to screen each soil sample for the <br /> presence of volatile hydrocarbons during drilling. Lithologic logs will <br /> be prepared for each boring to describe the materials encountered during <br /> drilling. Augers will be steam cleaned between borings and soil cuttings <br /> will be stored on site for later disposal. <br /> l <br /> At least one soil sample per boring willlllibe submitted to McLaren <br /> Analytical Laboratory for total petroleum hydrocarbon (TPH) and benzene, <br /> toluene, xylene, and ethylbenzene (BTXE) analyses by EPA Methods 8015 <br /> (modified) and 8020, respectively. The soil samples will be collected and <br /> transported under chain-of-custody in a refrigerated ice chest. <br /> rI� <br /> L. 6 <br />