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Ms. Victoria McCartney S E C O R <br /> June 11, 2004 <br /> Page 2 <br /> CONE PENETROMETER TEST AND SAMPLE COLLECTION <br /> Between March 29 and April 8, 2004, SECOR supervised Gregg In Situ Incorporated (Gregg) of <br /> Martinez, California, as they advanced two CPT borings (CPT-5 and CPT-6) to assess soil lithology <br /> and stratigraphy at each loc ion. Borings CPT-5 and CPT-6 were advanced to depths of <br /> approximately 175 feet and 11f�feet below ground surface (bgs), respectively. Lithology and pore <br /> pressure were continuously recorded and used to develop a hydrogeologic profile in the vicinity of <br /> the borings. During completion of boring for CPT-5, steel rods were advanced to 90 feet bgs and <br /> retracted after failing to encounter a shallow sand layer. The rods were re-advanced to <br /> approximately 175 feet bgs in the same borehole. Lithology and pore pressure was recorded and <br /> duplicated for CPT-5 (CPT-5A) between 0 and 90 feet bgs. Immediately adjacent to each CPT <br /> borehole a second direct-push borehole was advanced to collect depth-discrete groundwater <br /> samples. CPT logs are presented in Attachment 3. The findings of the CPT activities are <br /> summarized below. <br /> Subsurface Conditions <br /> Soil lithologies encountered during advancement of the CPT borings consisted predominantly of silt <br /> to clayey silt with minor amounts of silty clay, sandy silt, and clay. Sand lenses were encountered <br /> from approximately 105 feet to 106 feet bgs, 113 feet to 117 feet bgs, and 127 feet to 130 feet bgs at <br /> CPT-5N, nd from approximately 32 feet to 34 feet bgs at CPT-6. <br /> Hydropunch Groundwater Sampling <br /> An additional direct-push boring was advanced near each CPT boring and a total of five groundwater <br /> samples were collected from water-bearing zones identified during the advancement of the CPT <br /> borings. The groundwater samples were collected using a Hydropunch at depths of 81 feet bgs and <br /> 116 feet bgs next to CPT-5, and at depths of 35 feet bgs, 67 feet bgs, and 110 feet bgs near CPT-6. <br /> The findings of CPT activities are summarized below. ' �... <br /> Hydropunch groundwater samples were submitted to Lancaster Laboratories Incorporated <br /> (Lancaster) of Lancaster Pennsylvania for chemical analysis. The samples were analyzed for total <br /> petroleum hydrocarbons as gasoline (TPHg), total petroleum hydrocarbons as diesel (TPHd), total <br /> petroleum hydrocarbons as motor oil (TPHmo), benzene, toluene, ethylbenzene, total xylenes <br /> (BTEX), methyl tertiary butyl ether (MtBE), tertiary butyl alcohol (TBA), tertiary amyl methyl ether <br /> (TAME), ethyl tertiary butyl ether (EtBE), di-isopropyl ether (DIPE), ethylene dibromide (EDB), and <br /> 1,2-dichloroethane (1,2-DCA). Hydropunch groundwater analytical data and chain-of-custody <br /> documentation is presented in the laboratory analytical report in Attachment 4 and summarized <br /> below and in Table 1. <br /> I:1Chevron1905571REPORTS1200412004 Site Assessment. RevS.doc <br />