Laserfiche WebLink
-1 6 <br /> Verification Soil and Ground-Water Investigation <br /> The results of the soil gas investigation showed some consistencies with the findings from <br /> p--vious investigations in that toluene and xylenes had been detected at low concentrations <br /> in a composEe soil sample from the former ship building yard In addition, certain metals in <br /> coil sample from this area were somewhat elevated relative to soil metal concentrations at <br /> su:rounding areas on the site. However, the results of this method of soil gas investigation <br /> are ?enerally not definitive with regard to the source of VOCs because the soil gas may be <br /> em.,nating from soil and/or ground water. Further, those results are not quantiflable in <br /> terms of relating soil gas ion counts to actual concentrations in soil and/or ground water. <br /> Therefore, a limited verification investigation of soil and ground water was conducted by <br /> LSCE in July 1993 to identify the source of VOCs in the soil gases and to determine <br /> whether contaminants were present at concentrations of concern. The results of the <br /> verification investigation are summarized below and are described in detail in Section III of <br /> this report <br /> Four borings were dri"-d to collect soil and ground-water samples in the areas of highest <br /> soil gas fluxes identified in the earlier soil gas survey (Figure 4). The soil samples were <br /> analyzed for selected priority pollutant metals, TPH as motor oil and diesel, and BTEX. In <br /> addition, the sample with the highest total metal concentrations was analyzed for soluble <br /> portions of the four selected metals (citric acid WET for each metal, plus deionized water <br /> analysis for lead). The ground-water samples were analyzed for TPH as motor oil and <br /> diesel, and BTEX. Soil and ground-water samples were also scanned for TPH as gasoline <br /> and naphthalenes. <br /> he verification investigation results identified impacts of historical ship-building activities <br /> on soil and ground water. The soil analytical results identified designated concentrations of <br /> notal petroleum hydrocarbons as motor oil, total lead concentrations equaling and slightly <br />