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Mr. James Barton <br /> November 2, 2004 <br /> Page 3 <br /> of plume boundaries will be assessed. Technologies that actively control lateral spread of <br /> the plume boundaries will also be evaluated as to their feasibility. The pilot study will be <br /> started within 30 days after the bench scale study is completed. <br /> 7. Upon approval of the CAP or work plan, ENSR will take the appropriate actions to complete <br /> tasks associated with the approved feasible remediation option. A pilot study will be <br /> conducted within 45 days of CAP approval, if warranted. <br /> Based on the RSE, comparative analysis, analysis of groundwater data from new wells in Unit <br /> C and Unit D, groundwater parameters related to intrinsic biodegradation, GE and feasible <br /> remedial options recommended in the CAP or work plan, a pilot study may be proposed. Due <br /> to the large volume of effort and coordination required to complete items 1 though 7, ENSR is <br /> requesting a submittal date for the CAP or work plan no sooner than December 30, 2004. <br /> Proposed Well Installations <br /> To assess the groundwater gradient and the downgradient and cross-gradient extent of <br /> petroleum hydrocarbons constituents in groundwater in Unit C and Unit D, ENSR proposes the <br /> installation of two additional groundwater monitoring wells (MW-31 and MW-32). The locations <br /> of the proposed monitoring well are illustrated on Figure 2. <br /> Soil Borings and Sampling <br /> A geologist from ENSR will observe Cascade Drilling, Incorporated, of Rancho Cordova, <br /> California advance soil borings MW-31 and MW-32 to approximate depths of 90 feet and <br /> 103 feet bgs, respectively. The borings will be advanced using a truck mounted drill rig using <br /> 8'/a-inch diameter hollow stem augers. Soil samples will be collected at five-foot intervals and <br /> at changes in lithology to the total depth drilled. Soil samples will be field screened for the <br /> presence of volatile organic compounds (VOCs) using a photoionization detector (PID). Soil <br /> samples will be logged using Unified Soil Classification System (USCS) visual and manual <br /> methods. Lithologic descriptions, PID readings, and other pertinent drilling information will be <br /> recorded on the boring logs. Soil borings MW-31 and MW-32 will be completed as groundwater <br /> monitoring wells MW-31 and MW-32, respectively. Field methods and procedures to be used <br /> by ENSR during drilling and installation of the proposed wells are summarized in <br /> Attachment B. <br /> Soil Sample Analysis <br /> Selected soil samples will be submitted for chemical analysis based on elevated PID readings, <br /> sample depth, soil lithologic data and field observations. A minimum of one soil sample from <br /> each boring will be submitted for chemical analysis. <br /> Selected soil samples will be submitted to California Laboratory Services (CLS) in Rancho <br /> Cordova, California under chain-of-custody protocol. Soil samples will be analyzed for <br /> J:\Projects10694015098-293\Final\Reports\Work PlansM98 Work Plan-SVE AS System.doc <br />