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Chevron/S. El Dorado 16 <br /> August 1990 <br /> TABLE 3 <br /> BOREHOLE SOIL ANALYTICAL RESULTS <br /> parts per million (ppm) <br /> TOTAL <br /> SAMPLE DEPTH ETHYL- TPH-AS- OIL-AND- <br /> I.D. (ft.) BENZENE TOLUENE BENZENE XYLENES GASOLINE GREASE <br /> MW-1D 41 .5 NA NA NA NA NA <5 <br /> MW-1E 46.0 <0.005 <0.005 <0.005 <0.015 <10 NA <br /> MW-2F 47.0 <0.005 <0.005 <0.005 <0.015 <10 NA <br /> MW-3B 18.5 0.08 0.2 0.03 0.2 <10 NA <br /> MW-3C 34.0 0.05 <0.005 0.01 0.03 <10 NA <br /> _a MW-3E 45.5 <0.005 <0.005 <0.005 <0.015 <10 NA <br /> _ NA = Not Analyzed <br /> GROUNDWATER <br /> During the subsurface investigation, groundwater was <br /> encountered in the three boreholes at between 47.0-and 48.0-feet <br /> below ground surface. The groundwater-monitoring data collected <br /> on August 20, 1990 were combined with the well survey data to <br /> i <br /> Ma produce the groundwater-contour map presented as Figure 5. The <br /> map shows a generally northwest sloping groundwater gradient of <br /> 0.02 ft/ft. <br /> The results of the laboratory analyses performed on the <br /> " groundwater samples obtained from the site on August 20, 1990 <br /> indicated measurable concentrations of BTEX and TPH-as-gasoline <br /> in the water samples collected from monitoring wells MW-1 and <br /> " MW-•3. The BTEX, TPH-as-gasoline, and total oil-and-grease <br /> analytica .results are summarized in Table 4. The laboratory <br /> reports and Chain-of-Custody Manifests are included in Appenr-ix <br /> r - -- — -J. -The-groundwater--sample-_from-MW-1--was--also,-analyzed-for-TOG - -----_ ---, <br /> using EPA Method 413.2. The measured concentration was 1. ppm. <br /> `-� Figure 6 shows the benzene concentration and TPH-as-gasoline <br /> concentrations in each monitoring well. <br /> -14i GROUNDWATER <br /> 'TECHNOLOGY,INC <br /> li <br />