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respectively. Aromatic hydrocarbons, including benzo-ne, toluene, <br /> ethylbenzene, and xylenes (BTEX) were not detected in most of the <br /> soil samples analyzed. However, BTEX concentrations ok:0.007 ppsn <br /> or less were detected in samples from 15.5 feet below grade in boring <br /> B-14, from 25.5 and 36.5 feet below <br /> grade ndwaterng samples 10 cd collected <br /> ori <br /> 15,3 feet below grade in boring B-11. <br /> from all four monitoring wells contained no detectable <br /> concentrations ,,f TPPH or BTEX. <br /> ER74.West <br /> In March 1591, ERM-West drilled soil boring B-16 approximately 1.5 <br /> Ie was coat the <br /> feet to the west of boring B-15. <br /> One <br /> nn soilrm the amp, of diesel asereported <br /> 25.5- to 26.0-foot interval to <br /> by WGR. Laboratory analyses showed a TPH level of 1,300 µglkg. A <br /> fromch sample ( 50Amg/l.tical r.:sults <br /> fro the �'oundwatersample showed diesel at 1 <br /> Groundwater samples were also collected from "he four existing <br /> monitoring wells. Analytical results are shown in Table 1-2. <br /> �ya3�^9ola�y <br /> All of the on-site monitoring wePs were surveyed for top-a casing <br /> . elevations with respect to <br /> mean <br /> and again sea level bn November y John E. ll991T• land <br /> The <br /> surveyor, LS4811, in Octobermonument at the <br /> r USGS benchmark is a 3/4-inch iron Dpin Groundwater flow <br /> intersection of Fresno Street. and Navy <br /> beneath the site on October 3, 19;)9 was in oeast-southeast loodirection <br /> o.t a very shallow gradient of G.1%. This gr <br /> does not correspond to the northwest g-r(rindwater flow direction <br /> estimated for September 11, 1987, and the north flow direction <br /> flow <br /> estimated for March 28, 1988. The accuracy of these earlier ear to <br /> directions is suspect since a professional surveyor does not app <br /> have been used. In addition, the flow directions <br /> maybe <br /> 1 e aundwa er <br /> ected by <br /> the ongoing drought, which is causing <br /> pL,ping in the area. <br /> Surface water in the area is limited to the Mo:oX Slough, which <br /> flows intermittently in a northwest direction approximately n <br /> ile <br /> _ north of the site and discharges into the Stockton Deep Water <br /> Channel. <br /> 1-4 <br /> —.. a.�n - err r�s�newwwe�na�RIRRf - <br />