Laserfiche WebLink
BASELINE ASSESSMENT REPORT <br /> Site Number 11192 <br /> 1403 Country Club Boulevard <br /> Stockton, California <br /> 4. Supplemental Site Assessment Work <br /> EMCON measured PID headspace readings beneath each gasoline dispenser on July 11, 1994. <br /> Volatile organic vapors were detected under five of the six dispensers. The PID readings <br /> ranged from 1.1 ppm at the southernmost of the northern pump islands to 28.3 ppm at the <br /> northernmost of the southern pump islands. <br /> On November 9 and 10, 1994, EMCON conducted supplemental assessment activities at the <br /> site. Four exploratory soil borings (THP-1 through THP-4) were advanced using CPT drilling <br /> methods. The location of the four soil borings is shown in Figure A-1. The borings were <br /> advanced to depths of approximately 26 to 36 feet bgs. Soil types Iogged during drilling <br /> included silty clay, sandy clay, and sand to the total depths explored. Groundwater was not <br /> encountered in borings THP-1 and THP-2. No product odor was noted on the drilling logs <br /> (labeled HP-1 through HP-4; Attachment D). PID readings were obtained every 5 feet, if <br /> possible. The highest PID reading was 4.6 ppm at 25 feet bgs in boring THP-4. <br /> Two soil samples were collected and submitted for laboratory analysis from each boring for <br /> BTEX, TPH-G, TPH-D, and TPH-O. The deepest sample from each boring was also analyzed <br /> for HVOCs (EPA Method 8010). None of the constituents analyzed for was detected in the <br /> soil samples(Table A-1). <br /> A groundwater sample was collected from borings THP-3 and THP-4 by using HydroPunch"m <br /> equipment. They were submitted for laboratory analysis of the same list of parameters as the <br /> soil samples. THP-0 (2,200 ppb) and toluene (0.7 ppb) were detected in the groundwater <br /> sample collected from HydroPunch boring THP-3 (Table A-1). TPH-O (1,400 ppb) and <br /> 1,2-DCA (4.2 ppb) were detected in the groundwater sample collected from HydroPunch <br /> boring THP-4. A copy of the laboratory report is included in Attachment D. <br /> UMS/R.PT/1 1192RPr.d07-94/LAM/1b:5 Rev.0.02103195 <br /> 0952-090.03 <br /> 1 i <br />