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Fil r) <br /> Fi <br /> With the approval of the San Joaquin Local Health <br /> Ft" District , RAMCON backfilled the excavation -with clean pea <br /> gravel and covered it with concrete. <br /> F3 .0 CURRENT INVESTIGATION <br /> With the permission of the SJLHD and because TPHg and <br /> F BTEX detection limits reported in analyses of samples from <br /> the tank cavity were considered unacceptable by the county, <br /> �F <br /> Roger Foott Associates, Inc . observed the drilling of three <br /> soil borings in locations corresponding to the previous <br /> samples and observed excavation of contaminated soil from <br /> the area near the former dispenser . <br /> 3 . 1 Soil Borings <br /> Soil borings 'B1, B2, and B3 were drilled on January 15, <br /> 1991 , in locations corresponding approximately to earlier <br /> samples within the former tank cavity at depths of <br /> approximately 14 to 15 ft using a Mobile B-53 drilling rig <br /> equipped with 8-in diameter, continuous-flight, hollow-stem <br /> augers ; The drilling equipment was operated by Woodward <br /> Drilling Company of Rio Vista, California, a licensed well <br /> Fidriller. Boring B1 reached a maximum depth of 11 . 5 ft . <br /> Borings B2 and B3 reached a maximum depth of 16. 5 ft . The <br /> F! auger flights were steam-cleaned prior to use in each boring <br /> to minimize the possibility of downhole or cross-boring <br /> F <br /> contamination. The drilling was observed by a field <br /> geologist and the earth material in the borings were logged <br /> Fit` as drilled. <br /> Soil samples were collected at the base of each boring <br /> hi using a California-modified, split-spoon sampler equipped <br /> with clean brass sleeves . Samples were collected by <br /> drilling- to a point immediately above the sampling depth, <br /> F1 and then driving the sampler into the soil through the <br />�� hollow center of the augers . <br /> ROGER FOOTT ASSOCIATES, INC. <br /> -5- <br />