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Mr Harlan Knoll Environmental <br /> 27 March 1998 Resources <br /> Page 2 Management <br /> and groundwater analytical results for the two tank excavations are <br /> presented in Tables 1 and 2 <br /> Following the removal of the additional soil and groundwater, the <br /> analytical results were reviewed by ERM The information generated <br /> during the tank removal activities and the Phase II Environmental Site <br /> Assessment (Phase II ESA) appear to indicate that the majority of the <br /> impact caused by the two former USTs occurs within site groundwater <br /> This assessment is based on the depth of the tanks relative to the water <br /> table, the fine-grained soil types present at the site, and results of field <br /> screening of soil cores with an organic vapor analyzer (OVA) during the <br /> Phase 11 ESA In addition, all samples containing elevated concentrations <br /> of Total Petroleum Hydrocarbons as gasoline (TPH-g) and related <br /> compounds were collected within 2 feet of the water table Based on this <br /> information, ERM has developed a sampling and analysis plan to <br /> characterize the extent of TPH-g impact to soil and groundwater in the <br /> vicinity of the two tanks The scope of the proposed investigation is <br /> presented in the following section <br /> PROPOSED SCOPE OF ADDITIONAL WORK <br /> The purpose of this proposed scope of work is to characterize the <br /> occurrence of TPH-g and related compounds in soil in the vicinity of the <br /> UST excavations and determine the extent of impact to groundwater Per <br /> our phone conversation on 27 March 1998, it is understood that the <br /> County permit obtained for previous investigation at the site is still valid <br /> contingent on approval of this workplan by the County and use of the <br /> previous drilling contractor <br /> To determine the extent of soil impact in the vicinity of the former USTs, <br /> soil samples will be collected in the unsaturated zone (approximately 2 to <br /> 4 feet bgs) and directly above the water table (approximately 7 feet bgs) <br /> from the five locations identified in Figure 1 (UST#1) and Figure 2 <br /> (UST#2) The soil sampling locations will be continuously cored to the <br /> water table (approximately 10 feet bgs) and the soils will be field <br /> screened using an OVA If the field screening instruments indicate the <br /> presence of elevated hydrocarbon concentrations (based on previous <br /> screening results), an additional sampling location will be installed <br /> approximately 5 feet outward from the initial proposed location <br />