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HYDRDGEDLDC-.1C ASSESSMENT RESULTS AND <br /> 6 QUARTERLY GROUNDWATER MDNriromG REPORT <br /> 4445 Pershing Avenue Stockton California <br /> t <br /> 3.0 RESULTS <br /> 31 Soil_Boring and Sampling <br /> The soil boring was drilled to 40 feet below surface at the location shown on Figure 2, <br /> and was completed as a 4-inch-diameter groundwater monitoring well The boring was <br /> drilled using a 10-1/4-inch-diameter hollow-stem auger <br /> During drilling, the subsurface soils and alluvial materials of the unsaturated zone were <br /> sampled at 5-foot intervals Logs of the soil borings were generated based on field <br /> descriptions, and are included as Appendix D Soil samples were screened in the field, <br /> using a portable photoiornzat,on detector (PID) Results of PID screening are indicated <br /> on the boring logs <br /> 3.2 Analytical Results; Soil <br /> A total of three soil samples were analyzed for concentrations of a) TPH, as gasoline, <br /> by GC/FID Method 5030, b) BTEX by EPA Method 8020, c) ethylene dibromide by EPA <br /> Method 8240, and d) total lead by EPA Method 7421 <br /> The soil sample analytical results are summarized in Table 1 The laboratory analytical <br /> reports and chain-of-custody form are included in Appendix E <br /> 3 3 Groundwater Monitoring Well Installation, Development, and Surveying <br /> One 4-inch-diameter groundwater monitoring well, MW-4, was installed in the soil boring <br /> t (Figure 2) Groundwater monitoring well construction details are included in Appendix D <br /> I Based on water levels observed during the drilling of the well, perforated casing was set <br /> from 20 to 40 feet below surface The well was capped with a locking wellhead cap and <br /> secured by a water-tight, traffic-rated wellhead vault The top-of-casing elevation above <br /> mean sea level of the well was surveyed to the City of Stockton bench mark #265 by <br /> Tom O Morrow, Inc , of West Sacramento, California, a licensed surveyor <br /> Approximately three well volumes were developed from the well using a surge block with <br /> a 3-inch bailer The development water was stored temporarily on site in DOT-approved <br /> 1 55-gallon drums, pending laboratory analysis of the groundwater samples Following <br /> receipt of the laboratory results, the development water will be transported, by a licensed <br /> Ehauler, from the Shell service station to an appropriate disposal facility <br /> 89.016A OMR 4 <br />