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Harding Lawson Associates <br /> January 14, 1991 <br /> 20264,004.02 <br /> John Breuner Company <br /> Mr. Peter Meier <br /> Page 4 <br /> Task 1:Literature Review-Records Search <br /> This task consists of conducting a literature review and records search to ascertain the geologic and <br /> groundwater conditions at the site. The purpose of this task is to provide information on local <br /> subsurface geologic formations and depth to groundwater at the site. This nformationrwill be:used to <br /> confirm the,anticipated.groundwater conditions and.to-bonfirm u evaluation that insufficient potential <br /> fexists for the petroleum hydrocarbons to have migrated to groundwater to warrant a groundwater.­ <br /> nvestigation., <br /> investigation.,Additionally;this information will be u ed til choose anticipated boring depths. This <br /> task will be conducted by reviewing published and unpublished geologic and hydrogeologic literature <br /> for the site vicinity. Additionally, HLA will review the files of local and state agencies for cases of <br /> identified soil or groundwater contamination in the site vicinity, as these reports generally contain <br /> detailed descriptions of geologic and groundwater conditions. For the balance of this work plan, we <br /> will assume groundwater is relatively deep, greater than 50 feet. <br /> Task 2: Soil investigation <br /> This task consists of C ii ting soil samples from below the dispenser. The purpose of these samples is <br /> to evaluate the extent of petroleum hydrocarbons`in-soil in thedispenser area. As an initial step of this <br /> task, HLA personnel will interview Levine-Fricke staff to confirm if soils containing elevated <br /> concentrations of petroleum hydrocarbons.underneath_the-former dispenser were_removed or buried in <br /> place.�—If soil containing petroleum hydrocarbons were not excavated,they,will-be removed and the <br /> extent of petroleum products in the soils will be assessed by collecting and analyzing excavation side <br /> wall and floor samples. If they were excavated, an investigation will be performed to evaluate the <br /> vertical extent of petroleum products in soils, in.ac ordZ Zee regulatory guidelines"., <br /> If soil is to be removed from beneath the former dispenser, a backhoe will be used to excavate an area <br /> approximately 10 feet on sides and�5 feet deep in the former dispenser area. Approximately 18.5 cubic <br /> yards of soil will-be excavated and stockpiled onsite. Soil samples will.be collected from the side walls_ l� <br /> and floor of the excavation and from the stockpiled soil and a alyzed in an onsite mobile laboratory`�C y <br /> Analytical results will be used to confirm that soils containing elevated--caacB[ltlatioris of petroleum <br /> hydrocarbons have been removed. An acceptable concentration in soil will be assessed by performing a <br /> leaching tential analysis after depth to groundwater' accurately known) Excavation will be <br /> r continued until sample analysis.�on =ms soils containing an accep a concentration of petroleum <br /> hydrocarbons. Soil samples will be analyzed for TPH as_gasoline and diesel using modified EPA Test <br /> Method 1801 51"d and for BTEX using EPA Test Method 8020! Analysis will be conducted using a mobile <br /> laboratory, which is state-certified for the analyses requested. <br /> If soil from underneath the former dispenser g elevated concentrations of petroleum <br /> hydrocarbons were previously removed, one boring designated B-1, will be drilled at the former <br /> dispenser location and soil samples will be ected and analyzed to assess the vertical distribution of <br /> petroleum products in the soil. Plate 2 presents the boring location. After receiving the results of <br /> laboratory analysis and obtaining an_aurate estimate on depth to groundwater, leaching potential <br /> analysis will be performed to assess if the site has been adequately remediated. <br />