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California Regional Water Quality Control Board <br /> Central Valley Region <br /> Steven T.Butler,Chair <br /> Winston H.Ilicicox — c_.3 Gray Davis <br /> Secretaiyfor Sacramento Main Office Governor <br /> Environme'rtal Internet Address: http:h%m\v,s\vrcb.ca.gov/—rwgcb5 �) <br /> Protection 3443 ROIItiel'Road,Suite A,Sacramento,California 95827-3003 <br /> Phone(916)255-3000•FAX(916)255-3015 <br /> r• <br /> 31 July 2000 <br /> o <br /> Mr. James Mills w _ <br /> Westrec Marinas <br /> 14900 West Highway 12 <br /> Lodi, California 95242 <br /> REVIEW OF TI4E FEASIBILITY STUDY/REMEDIAL OPTIONS EVALUATION, TOWER <br /> PARK MARINA, SAN JOAQUIN COUNTY <br /> I have reviewed the 10 July 2000 Feasibility Study/Remedial Options Evaluation Report (Report) <br /> submitted by SECOR International, Inc. (SECOR) on behalf of Westrec Marinas for the Tower Park <br /> Marina, 14900 West Highway 12, Lodi. The site is an operating marina along Little Potato Slough. The <br /> location of the site along the levee limits any intrusive activities, due to the U.S. Army Corps of <br /> Engineers' classification of the levee as "intrinsically unsafe." SECOR states that obtaining a permit to <br /> perform invasive activities in the levee is likely infeasible and could result in substantial risk for future <br /> levee failure. <br /> In 1995, SECOR installed oxygen-releasing compound (ORC) filter socks in wells MW-2, MW-3, and <br /> MW-4. The socks added oxygen to the formation in efforts to enhance aerobic biodegradation at the <br /> site. However, the results indicated that the socks were not effective, due to the competing oxygen <br /> demand between the contaminants and the organic-rich soils beneath the site. In response to a <br /> 28 April 2000 letter request by Board staff, SECOR prepared this Report evaluating four remedial <br /> options to determine a feasible method to remove free product from well MW-3 and to reduce dissolved <br /> phase concentration in groundwater. The four options evaluated are free product removal, groundwater <br /> recovery (pump and treat), soil vapor extraction, and in-situ bioremediation. <br /> Groundwater recovery involves pumping groundwater and product from the well, passing the recovered <br /> groundwater through a treatment system to remove hydrocarbons, and disposing of the treated water. <br /> SECOR does not believe that a pump and treat system would be effective, as it does not address source <br /> contaminants bound to soil and would remove large quantities of water and very little of the dissolved <br /> contaminants. Also, disposal of the treated water would be difficult, as the marina does not have access <br /> to the sanitary sewer system. Therefore, SECOR does not recommend instituting this option. <br /> Soil vapor extraction removes contaminants from the subsurface soil using groundwater extraction to <br /> lower the water table and a vacuum set in the vadose zone to extract soil vapor. Soil vapor is widely <br /> used for lighter volatile organic compounds, such as gasoline. The contamination present at the site is <br /> primarily diesel range hydrocarbons; therefore, SECOR states that these constituents are not conducive <br /> to soil vapor extraction. Also, this method would require installation of soil vapor extraction wells, <br /> California Environmental Protection Agency <br /> Via' Recycled Paper <br />