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Additional Soil and Groundwater Investigation Report Canepa s Car Wash(Park Street) May 8,2002 Page 3 3 3 GROUNDWATER SAMPLING Twenty-one groundwater samples for laboratory analysis were collected from the hydropunch borings ' from March 25 through March 28, 2002 The groundwater samples were collected directly from the outlet of the stainless steel bailer Each water ' sample was collected by filling three 40-m1 volatile organic analysis (VOA) vials The sample containers were labeled for sample identification and placed in a cooler chilled with blue ace The water samples were delivered under chain-of-custody procedures to Argon Laboratories, Inc , in Ceres, California ' 3.4 SOIL SAMPLING The soil samples from SB 1 for laboratory analysts were collected into clean stainless steel sleeves using a 12-im,h piston actuated sampler, from 66 feet to 82 feet, at approximately 6 foot intervals The stainless steel sleeve was removed from the bottom of the sampler, the ends covered with a clean Teflon® sheet, closed with plastic end caps, labeled and placed in a cooler chilled with blue ice The SB I logis included ' in Appendix B 3.5 LABORATORY ANALYSES The soil and groundwater samples collected from the soil and hydropunch borings were analyzed for benzene, toluene, ethyl benzene, total xylenes (BTEX), and methyl tert-butyl ether (MTBE) by EPA Method 8020A, and for total petroleum hydrocarbons quantified as gasoline (TPH-G) by EPA Method t 80I5 M The analytical parameters and deter tion limits are presented in Table I and Table 2 of Sections 4 2 and 4 3, respectively Analytical laboratory certificates of analysts are included in Appendix C ' 4.0 INVESTIGATION RESULTS 4 1 FIELD OBSERVATIONS AND CPT RESULTS Field observations made during the installation of the CPT and hydropunch borings consist of the CPT and soil boring logs pertaining to site geology and the location and sample depths of the hydropunch borings The Presentation of Cone Penetration Test Data(including the CPT1 and CPT2 boring logs), are ' included in Appendix B The CPT Iogs from CPT1 and CPT2 were compared in order to evaluate the lateral continuity of the lithology and to identify three discrete depth hydropunch sample locations Based on a comparison of the CPT1 and CPT2 logs, approximately three feet of silty sand/sand and sand are present at approximately 54 to 56 feet bgs and 53 to 56 feet bgs, respectively All of the monitor wells on site are screened across this interval A horizon of silty sand/sand, sand and gravelly sand from 78 to 83 feet bgs in CPT1 appears ' to correspond to a horizon of sand from 74 5 to 78 feet bgs in CPT2 Hydropunch samples HP I and HP4 were collected from separate borings to correspond with these horizons in CPT1 and CPT2, respectively A horizon of silty sand/sand, sand, and gravelly sand was logged in CPT1 from 104 to 116 feet bgs The ' cone bearing pressure reached a maximum at around 108 feet bgs indicating very dense material at that depth A horizon of silty sand/sand, sandy silt, and gravelly sand was logged in CPT2 from. 104 5 feet bgs to the refusal depth at 107 feet bgs, and the soil behavior type and density correspond to that logged at ' CPT1 Hydropunch samples HP2 and HP6 were collected from separate borings to correspond with these horizons in CPTI and CPT2, respectively, to sample the upper portion of these permeable horizons iCONDOR