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Sojl and Groundwater Investigahon Report'"'"`"'"'"`" 730 E Channel Street,Stockton,CA June 1,2004 Page 2 1n a letter dated November 4, 2003, to Ms Garcia, Victoria McCartney of the SJCEHD directed Raymond Investment Corporation to submit a work plan to investigate the lateral and vertical extent of contamination at the site Condor prepared the Soil and Groundwater Investigation Work Plan, dated February 19, 2004, at the request of Ms Garcia in response to that letter Ms McCartney approved the Iwork plan, with modifications, in a letter dated March 17, 2004 The modifications included the elimination of three proposed bonngs in the vicinity of the former UST location and the elimination of one proposed boring in the vicinity of the former location of the diesel filter and piping Ms McCartney r �i also directed the soil and groundwater samples to be analyzed for 1,2-dibromoethane (EDB), methanol, and ethanol 3 0 DIRECT PUSH BORING FIELD PROCEDURES This section includes a description of site preparation activities and direct push boring procedures 31 SITE PREPARATION A drilling permit application was prepared by Condor and submitted to the SJCEHD for six proposed direct push borings Condor received the drilling permit prior to initiating any fieldwork The proposed boring locations were marked with white paint and Underground Service Alert (USA) was notified 48 hours in advance of the fieldwork to locate and identify underground utilities in and near the work area The SJCEHD was notified of the fieldwork schedule 72 hours in advance 32 DIRECT PUSH BORING PROCEDURES A Condor geologist was on site to supervise the work Prior to commencement of fieldwork, a tailgate safety meeting was held and a site-specific Health and Safety Plan was discussed with, and presented to, all field personnel for their signatures The investigation included the advancement of six direct push borings (SB-1, SB-2, SB-3, SB-4, SB-5, and SB-6) to collect soil and groundwater samples on May 5 and 6, 2004, using a dual tube sampling system The boring locations are shown in Figure 2, Appendix A Upon completion of the boring and sampling, the boreholes were backfilled with a grout consisting of neat cement with less than five percent - bentonite powder The grout was tremied into the boreholes 3 2 1 Soil Sampling I All six borings were advanced to a depth of approximately 40 feet bgs Continuous core soil samples were collected from the borings using a dual tube soil sampling system The soil sampling system has a 2 125- inch outside diameter outer casing and a 1 0-inch outside diameter inner rod string A clean, single use, 1 125-inch inside diameter clear polyethylene terephthalate — glycol modified (PETG) liner is attached to the end of the inner rod stung and placed inside the outer casing As the casing is hydraulically advanced, the cutting shoe on the leading end of the outer casing shears a 1 125-inch outside diameter soil core that is collected inside the PETG liner The soil sampling equipment was cleaned prior to collecting the samples using laboratory-grade, non-phosphate detergent and deionized water and double rinsed with deionized water During the sampling, the soil sampler was driven in four-foot intervals The sample liner was extracted from the sampler and used for geological logging and field observations The soil samples were logged according to the Unified Soil Classification System (USCS) Portions of the soil samples were placed in • polyethylene bags and checked with a photoionizatiori detector (PID) for the presence of organic vapors 1 t � SCA CONDOR