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/b SOTAIt Environmental Technology Inc = Apr Due to the likely presence of undergr and utilities located in the public right of way on North Wilson Way, it was ecided to hand clear the first five feet of monitoring wells MW-7 and A4W-, using a hand auger While hand clearing ' MW-9, an underground sewer line was encountered. Two unsuccessful attempts were made to reloca e e monitoring well in the general vicinity of the original location In consultation with UHI and the County of San Joaquin Environmental Health Division it was decided by SOTA to ost one the drilling_ of monitoring well MW-9 until a later date following utility clearance rom the can ec m agenc e e o remaining monitoring wells (MW-7 and MW-8) were drilled to a maximum depth of 85 feet bgs The wells are 4-inches in ' diameter and constructed of schedule 40 PVC screen and blank casing Boring logs and well construction diagrams are presented in Appendix A and Figure 6, respectively. 4,IL Drilling and Installation Of Groundwater Monitoring Wells Following obtaining well permits from the County of San Joaquin Environmental Health Department, two groundwater monitoring wells (MW-7 and MW-8) were drilled on October 10 through 12, 1995 utilizing the services of Spectrum Exploration Inc , of Stockton California Spectrum Exploration is a ' State licensed C-57 drilling contractor. Their C-57 license is 512268 Spectrum Exploration, using a CME 75 hollow-stem auger drilling rig, drilled 8 1/2-inch diameter monitoring well borings to a maximum depth of 85 feet bgs A Modified California split spoon sampler was used to retrieve soil samples Upon retrieval, the front brass tubes were carefully removed from the sampler so as to minimize the volatilization within the container. Soil sample tube ends ' were immediately sealed with Teflon sheets, covered with polyethylene caps, secured with tape and labeled with indelible ink indicating sample location, depth, and time of sample Portions of the leading and trailing tubes for each sampling event were placed in one-pint Ball jars sealed with heavy duty aluminum foil and placed in the sun or near a heat source to promote volatilization of fuel compounds prior to head space analysis The remaining samples were used for lithologic description All residual samples and soil cuttings were temporarily stored in DOT approved 55-gallon drums for appropriate disposal later ! The soil samples retained for laboratory analysis were placed individually in zip- lock bags and stored in an ice chest cooled to 4°C with blue ice blocks Samples were transported to a state certified analytical laboratory at the end of ! each day of field work EPA protocols governing the chain of custody records were maintained and are presented along with the report As agreed with UHI and the County of San Joaquin Environmental Health ' Division (September 27, 1995), all soil borings were field screened using an OVA at 5-feet intervals, starting at 5-feet bgs to the maximum depth of the boring (Le 85 feet bgs). Soil samples obtained were analyzed for TPH (gasoline and diesel) by EPA Method 8015 Modified, and for BTEX by EPA Method 8020, starting at 5-feet bgs Thereafter samples were analyzed for TPH and BTEX at increments of 10 feet. However, if field screening results indicated an elevated concentration of TPH at intermediate depths, i e 5 feet, then analyzing 4