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. FOURTH QUARTER,2002 GROUNDWATER MONITORING REPORT AND ADDITIONAL ASSESSMENT REPORT JAMAR OIL DISTRIBUTION MARCH 2003 The samples were labeled with the date, time, and identifying well number, stored in a cooler at 4° Centigrade or less, and transported to a state certified laboratory under completed COC documentation Groundwater Analyses Groundwater samples were analyzed for TPH G and TPH D using EPA Method 8015 Modified and for BTEX, and the fuel oxygenates MTBE, DIPE, ETBE, TAME, and TBA using EPA Method 8260B The analyses were conducted by SunStar Laboratories, Inc, of Tustin, California, a California State certified laboratory, in accordance with state guidelines and EPA protocol This was the first tune the analysis for this site was done by this laboratory Copies of the laboratory reports with COC documentation are included in Appendix B The analytical data are summarized in Table 2 and shown on Figure 5 ADDITIONAL ASSESSMENT ACTIVIT]ES • A description of the additional assessment activities and methods is presented in the following sections Cone Penetrometer Testing On January 13-16, 2003, borings CPT-1B, CPT-2 and CPT-3 were advanced vertically to depths of 104-feet below ground surface (bgs), 122-feet bgs, and 117-feet bgs, respectively, (See Figure 4 for CPT locations) The CPT borings utilized a truck-mounted geoprobe drill ng equipped with 1 5-inch diameter hollow-stem rods A hydraulic ram was used at each boring to advance a cone penetrometer Tip resistance, sleeve friction, friction ratio (ratio between sleeve friction and tip resistance) and pore water pressure were continuously measured as the cone penetrometer advanced to total depth Continuous boring logs, which depict general lithology type, were generated utilizing the CPT computer program After completion, the borings were filled with cement grout using a tremmie pipe iii accordance with county regulations and drilling permit requirements The CPT boring logs are presented in Appendix C The lithologies were found to vary little across the area, with interbedded silt and clay being the dominant matenal According to the CPT data for CPT-1B, the on-site boring, there are four distinct lithologic units beneath this part of the investigation area an upper interbedded silt and clay layer from 8 to 67-feet bgs that contains a mucor sandy silt to sand layer between 26 and 30- feet bgs, an upper silty sand to sandy silt layer between 67 and 72-feet bgs, a lower interbedded silt and clay layer between 72 and 96-feet bgs, and a lower silty sand to gravelly sand unit that begins 96-feet bgs and extends beyond 104-feet bgs The CPT boring encountered refusal at 104- feet bgs in CPT-1B 5