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IT Corporation February 25, 2000 A Alember of The IT Croup Page 3 conducted. In addition the sample collected from MW-3 at 15 feet bgs was analyzed for 1,2-dichloroethane (1,2-DCA), ethylene dibromide (EDB) and total lead. Sampling and analytical methods are presented in Attachment A. • Groundwater Analysis. Groundwater samples wer submitted to a California State-certified laboratory for analysis. Groundwater samples were analyzed for the presence of TPH-g, BTEX, and for five oxygenates (MtBE, DIRE, ETBE, TAME and TBA) using EPA Methods 8015 Modified, 8020 and 8260, respectively. Groundwater samples were also analyzed for 1,2-DCA and EDB using EPA Method 8260. Well Surveying. Upon completion of well construction, the wells were surveyed by a licensed surveyor for location and elevation relative to mean sea level. The groundwater gradient was interpreted utilizing wellhead elevations and depths to water. Surveyor information is included as Attachment B. • DWR Well Search. A search for wells within a 2,000-foot radius of the site was conducted at the Department of Water Resources (DWR). Results of the search have been tabulated-and plotted on an area map. FINDINGS Subsurface Conditions Soils encountered during drilling(maximum explored depth of approximately 50 feet bgs) consisted of interbedded sands, silty sands, sandy silts and clayey silts. A more complete description of the subsurface lithology is shown on the boring logs presented in Attachment C. Soil Analytical Results TPH-g, BTEX compounds and MtBE were all non detect at the laboratory reporting limits. MtBE, 1,2-DCA, EDB and total lead were not detected in the selected soil sample from MW-3 at 15 feet bgs. Soil analytical data is summarized in Table 1 and laboratory reports with chain of custody(COC) documentation is included in Attachment D. Groundwater Analytical Results Gettler Ryan Inc. conducted monitoring well development, gauging and sampling on January 5, 2000. Groundwater flow is to the east at an approximate gradient of 0.003 feet/feet as shown on Figure 3. Groundwater gauging data is included in the Gettler Ryan Table 1 (Attachment E). TPH-g was not detected in any of the onsite wells. Benzene was reported in one well (MW-3) at a concentration of 0.61 parts per billion (ppb). MtBE was confirmed by EPA Method 8260 in wells MW-3 and MW-4 at 3.0 ppb and 5.0 ppb, respectively. Groundwater laboratory data is presented on Figure 4 and tabulated in the Gettler Ryan Tables 1 and 2 included in Attachment E. Field data sheets and groundwater laboratory reports are included in Attachment F. I \\SACRFP I\COMM ONlrancfp 11Proj ectslProjects191 1101111 A101021Report.doc