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Charl6s H. Bloom Company, Inc. September 2, 1988, 12176 Page 4 The original water sampling performed at the site by Precision was apparently not done according to any procedure planned to eliminate the possibility of cross -contamination of the water by the excavation equipment or tank removal procedures. The water sampling performed by Kaldveer Associates at the project site was planned to acquire the most representative water sample possible. The original water sample analytical results showed quantifiable diesel, gasoline and BTXE. Our water sample analytical results showed detectable gasoline (not quantifiable) , no detectable BT or E and only 25 ppb xylenes. REMEDIATION On August 10, 1988, a brief letter was transmitted to San Joaquin Local Health District, which presented the analytical results from our soil and water sampling program. In addition, the letter described the intended remediation procedures for the stockpiled soils and retained water. In response to this letter, the County Health Inspector verbally indicated that the water should be disposed of in the City storm drain system and the soil returned to the open excavation. On August 12, 1988, personnel from our office observed the backfilling of the open excavation, using the stockpiled soils. At the request of the County Health Inspector, a small volume (approximately three backhoe buckets) of the soil were spread out elsewhere on the site for aeration. At the request of Stockton Sanitary Department personnel, our field geologist pumped the retained water from the holding tank into a nearby sewer line. CONCLUSIONS AND RECOMMENDATIONS The analytical laboratory results of soil samples from both the original round of sampling/ testing and this round of sampling/ testing found no hydrocarbon contamination. A comparison of analytical results from the two rounds of water sampling/ testing show that the first round results are probably faulty due to improper sampling procedures. The second round results still show trace amounts of hydrocarbons. However, no soil samples taken at the project site have shown any hydrocarbon contamination. Therefore, in our opinion, any contamination of the groundwater is not associated with the subject underground fuel tank. Furthermore, the California Department of Health Services drinking water standard (maximum contaminate level, MCL) for xylenes is 1750 ppb, which is orders of magnitude greater than that found at this site. Kaldveer Associates