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December 22 , 1988 Page 4 <br /> Project 156-117 . 1 <br /> To prevent the transfer of contamination, all augers and <br /> down-hole tools were thoroughly steam cleaned between <br /> borings , all soil sampling apparatus was cleaned in a <br /> trisodium phosphate solution between each sampling run, and <br /> the bailer was cleaned in a trisodium phosphate solution <br /> between the development and sampling of each well . <br /> All cuttings generated during drilling operations and ground <br /> water obtained during development and sampling of the wells <br /> were contained in DOT approved 55 gallon drums and stored on <br /> site awaiting the results of chemical analysis of soil and <br /> ground water samples . <br /> Subsurface Conditions <br /> Subsurface soils consisting of interbedded clays , silty <br /> clays, silty sands , and sands were encountered in each <br /> boring . Each strata ranged from one foot to five feet in <br /> thickness . Imported fill material was encountered in DH-2 <br /> from a depth of three feet below ground surface extending to <br /> nine feet below ground surface. Ground water was initially <br /> encountered in borings DH-1 and DH-2 at approximately ten <br /> feet below ground surface , and in boring DH-3 at twelve and <br /> one half feet below ground surface . Logs of all exploratory <br /> borings are presented in Appendix A. <br /> Chemical Analyses <br /> Soil and ground water samples were obtained and analyzed for <br /> the constituents listed in Table 1 . <br /> Results of the analyses reveal none of the constituents <br /> tested for to be present above detection levels with the <br /> exception of the following : <br /> - acetone was detected in composite soil sample DH-2 at <br /> a concentration of 25 parts per billion ( ppb) . <br /> - p,p' -DDE (DDE) was detected in soil sample DH-3 ( 2 . 5 <br /> feet ) at a concentration of 43 ppb. <br /> - p, p' -DDT (DDT ) was detected in soil sample DH-3 ( 2 . 5 <br /> feet ) at a concentration of 65 ppb. <br /> - California Assessment Manual ( CAM) metals were <br /> detected in water sample MW-2 and soil sample DH-2 . <br /> Presently, the California Regional Water Quality Control <br /> Board (RWQCB) has not established a recommended soil clean-up <br /> level (RSCL) for acetone . However , the amount of acetone <br /> detected in sample DH-2 is only slightly above the detection <br /> level . <br /> GBetacAssociates Inc. <br />