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Ms . Casey Foley January 29, 1991 Page 3 The results of the laboratory analyses indicated that there were low to non-detectable concentrations of contaminants in soil samples below the locations of the _ former storage tanks and lines . Low concentrations of TPHg were detected in samples S-8 . 5-1 (2 . 3 ppm) and S-13-2 (1 . 1 ppm) ; 0 . 4 ppm xylene was detected in S-8 . 5-1 . Sample S-2-4 was found to contain 14 ppm TPHg, 1 . 2 ppm benzene, 2 . 2 ppm toluene, 0 . 2 ppm ethylbenzene, and 1 . 5 ppm total xylene isomers . Heavy metals were present in sample S-8 . 5-1 at acceptable concentrations thought to represent background, uncontaminated concentrations, based on our experience. With the approval of the San Joaquin Local Health District , _ RAMCON backfilled the excavation with clean pea gravel and covered it with concrete . With the permission of the SJLHD and because TPHg and BTEX detection limits found in samples from the tank cavity were considered unacceptable by the county, Roger Foott Associates , Inc . , observed the drilling of three soil _ borings in locations corresponding to the previous samples and excavation of contaminated soil near the dispenser . Samples from the borings showed no detectable TPHg or BTEX. The area of the former dispenser and sample S-2-4 was excavated using a backhoe operated by RAMCON. The excavation proceeded until field evidence and field _ instrument (photoionizing organic vapor meter) readings showed no indication of contamination. Five soil samples were collected from the walls and base of the excavation using hand sampling equipment . The samples were collected from the undisturbed soil at the limits of the excavation. The samples were each analyzed for TPHg and BTEX by Mobile Chem Labs . None of the samples showed detectable concentrations of these compounds . ROGER FOOTT ASSOCIATES, INC.