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Report-Soil and Groundwater invesitganon Cnnepa s Car Wash 6320 Pacific St Stmkton CA ' June 12 1998 Page-2- 3 FIELD AND ANALYTICAL METHODS ' Two soil borings (SB-1 and SB-2) were installed on May 6 and 7, 1998 at the Canepats Car Wash site This section includes a description of the site preparation, drilling procedures, soil sampling, Simuiprobe soil gas sampling, groundwater sampling, and laboratory analysis 3.1 SITE PREPARATION ' Prior to the fieldwork, drilling permits were obtained from the San Joaquin County PHS/EHD The boring locations were marked with white paint and Underground Service Alert (USA) was notified 72 hours in advance of the fieldwork The PHS/EHD was notified of the fieldwork schedule in advance 3.2 DRILLING PROCEDURES The fieldwork included the installation of two borings at the locations shown in Figure 2, Appendix A The boreholes were drilled by Spectrum Exploration, Inc (License 4512268) under the supervision of a Condor geologist Prior to commencement of work each day, a tailgate safety meeting was held and a site-specific Health and Safety Plan was discussed with and presented to all crewmembers for their signatures Following concrete cutting and initial hand digging, the borings were drilled using 8-inch O D , contmuous-flight, hollow-stem auger The auger was steam cleaned before each borehole was drilled The borings were drilled to approximately 70 feet below ground surface (bgs) for the purpose of collecting vadose zone soil samples, vadose zone soil gas screening samples, and simultaneous and discrete soil and groundwater samples in the saturated zone, with the Simulprobe sampling device The water table was approximately 40 feet bgs Upon completion of the drilling and sampling, the boreholes were grouted with a cement slurry I containing 3 to 5 percent bentonite The slurry was tremied into the borehole to avoid bridging All decontamination rmsate produced during the fieldwork was placed in a 55-gallon drum, scaled, labeled, and left on site pending laboratory analyses Disposal of hazardous materials, if any, is the responsibility Iof Canepa's Car Wash 3.3 SOIL SAMPLING Soil samples were collected using a five foot long, split-spoon sampler The soil sampling equipment was cleaned prior to collecting each sample The cleaning procedures consisted of washing the sampler in a solution of laboratory-grade, non-phosphate detergent and hydrocarbon-free water, and double rinsing with contammant-free water and/or by steam cleaning the larger components During the sampling, the split-spoon was driven ahead of the auger Soil samples were collected for laboratory analysis at five-foot intervals, or at significant lithologic changes, in the vadose zone Discrete soil samples were collected for analysis by driving a six-inch long brass tube into the undisturbed soil in the split-spoon sampler The remaining split-spoon contents were usW for geological I logging and organic vapor analyzer-photoionization detector (OVA-PID) measurements The samples selected for analyses were prepared, as described below, for shipment to the laboratory The samples �� CONDOR