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KEI-J92-0205 .R2 October 6, 1992 Page 3 was observed at a depth of about 12 feet below grade on July 30, 1992 . ANALYTICAL RESULTS All samples were analyzed by Sequoia Analytical Laboratory in Concord, California, and were accompanied by properly executed Chain of Custody documentation. All soil and water samples were analyzed for total petroleum hydrocarbons (TPH) as gasoline by EPA method 5030/modified 8015, TPH as diesel by EPA method 3550/modi- fied 8015 , and benzene, toluene, xylenes , and ethylbenzene (BTX&E) by EPA method 8020. Analytical results of the initial soil samples collected from the fuel tank pit indicated non-detectable concentrations of TPH as gasoline and BTX&E for all samples, except for 2 . 2 ppm of TPH as gasoline detected in sample SW2 , and 0 . 010 ppm of xylenes detected in sample SW4 . TPH as diesel was non-detectable in all samples , except for samples SW2 and SW3 , which showed concentrations of TPH as diesel at 120 ppm and 2 .7 ppm, respectively. However, after additional excavation, the analytical results of soil samples SW2- A, SW2-B, SW2-C, and SW2-D (collected from the southeast sidewall of the tank pit) indicated non-detectable concentrations of TPH as gasoline and BTX&E. TPH as diesel concentrations ranged from non- detectable to 9 5 ppm. The results of the soil analyses are sum- marized in Table 1. Analytical results of the water sample (W-1) collected from the fuel tank pit indicated 1, 500 ppb of TPH as gasoline, 2 , 800 ppb of TPH as diesel, and a non-detectable concentration of benzene The results of the water analyses are summarized in Table 2 Copies of jthe laboratory analyses and the Chain of Custody documentation are attached to this report. DISCUSSION AND RECOMMENDATIONS Based on the analytical results of the final soil samples that were collected during the removal of the underground storage tanks, it appears that the ma]ority of the contaminated soil in the vicinity of the former tank pit has been removed However, based on the analytical results of the ground water sample that was collected from the tank pit, and in accordance with the guidelines estab- lished by the RWQCB, further work is necessary at the site Therefore, in order to comply with the requirements of the RWQCB and the SJCPHS , KEI recommends the reimplementation of monitoring and sampling of the existing monitoring wells at the site. This program is recommended in order to evaluate the current ground water quality, and to determine the ground water flow direction