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Wright performed a site assessment, the results of which were presented in our report �-� dated May 10, 2001. This assessment revealed Total Petroleum Hydrocarbons as Diesel (TPHD) contaminants in the vicinity of the former tank pits and very low dissolved concentrations in groundwater north of the former pit area. PHS EHD requested additional assessment of the dissolved plume together with a resample of the adjacent irrigation well. The irrigation well had revealed very low concentrations of TPHD-like contaminants, which Wright attributed to possible self-oiling pump equipment in the well. Field Methods Exploratory Borings Eight exploratory borings were drilled at the site (Figure 1) on July 23, and August 28, 2001. The borings were positioned to ascertain distribution of the contaminants in site soil and groundwater; the three-groundwater monitoring wells were installed using the groundwater data collected from the uncased boreholes. Drilling permits were secured from the PHS EHD, and all utilities were cleared prior to doing the fieldwork. The borings were used to define the uppermost aquifer strata, and two selected borings advanced through the former tank pits were advanced through the uppermost aquifer to the contact of, and into the underlying confining strata of the uppermost aquifer. Boring B-10 was drilled next to the irrigation water well to ascertain the presence of the thick �-� clay aquitard noted on the well drillers log and to sample for soil and groundwater contaminants. A PHS EHD representative observed portions of the push boring work and borehole sealing. Moderate to severe flowing conditions were encountered in some boreholes, which required drilling methods to be modified depending upon the severity of the flowing condition. Some soil samples were not recovered in some instances of severe flowing since the sampler could not be advanced to the desired depth. The boreholes were drilled with truck mounted hollowstem auger and/or direct push drilling equipment. All drilling equipment and sampling tools were cleaned prior to arriving, between driving samples and before leaving the site. The augers were advanced to the desired sampling depth interval, and a drive split spoon sampler were driven ahead of the drill bit. The sampler was then retrieved and dissembled, and the soil filled brass or acetate liners retained for chemical analysis, were sealed with Teflon® paper and plastic endcaps, labeled, logged onto chain-of-custody forms and place in a chilled ice chest on crushed ice. Drill cuttings were drummed and left on-site. The boreholes were logged using the Unified Soil Classification System under the supervision of a registered geologist. Additional lithologic information was collected to describe the subsurface geology. Soil samples were field screened for presence of contaminants by checking for presence of odor and staining, and a photoionization meter was used for soil field vapor measurement use. Soil samples were collected at minimum Page 2