Laserfiche WebLink
Advanced <br /> GeoEnvironmental, Inc. -0=- <br /> 08 July 2004 <br /> AGE-NC Project No. 95-0142 <br /> Mr. Harlin Knoll <br /> San Joaquin County- Environmental Health Department <br /> 304 E. Weber Avenue, Third floor <br /> Stockton, California 95202 <br /> Subject: Soil Vapor Extraction Modification Work Plan <br /> Former STOCKTON PLATING Facility <br /> 632 South El Dorado Street, Stockton, California <br /> Dear Mr. Knoll: <br /> At the request of Mr. Richard Leland,Advanced GeoEnvironmental,hic. (AGE)has prepared a soil <br /> vapor extraction (SVE)-modification work plan for the site located at 632 South El Dorado Street, <br /> Stockton, California. AGE has proposed modifications associated with the design of a SVE system <br /> at the above-referenced site. In accordance with the SJCEHD-approved Corrective Action Plan <br /> (CAP), an electric catalytic oxidizer SVE unit(Solleco SCAT 250)has been in operation at the site <br /> since 10 December 2003. <br /> A general trend of decreasing influent hydrocarbon SVE concentrations was observed at the site <br /> between February 2004 and June 2004 (attached). Based on the manufacturer's guidelines and <br /> AGE's past remediation experience, a catalytic oxidizer SVE unit is usually most efficient when <br /> operational at hydrocarbon vapor concentrations between 2,000 µg/1 and 10,000 µg/1. <br /> Furthermore,between December 2003 and June 2004(6 months of operation),the cost of electricity <br /> (PG&E)to operate the catalytic oxidizer SVE unit at the site totaled above$10,000.00.The elevated <br /> PG&E cost can be attributed to the decreasing SVE vapor concentrations and a reduced efficiency <br /> of the catalytic oxidizer SVE system over this operational period.Therefore,based on the decreasing <br /> SVE hydrocarbon concentrations (less than 200 µg/1) and significant electrical utility costs, AGE <br /> proposes to replace the current catalytic oxidizer SVE unit with a more energy efficient,regenerative <br /> vacuum blower-based SVE system. Based on influent vacuum measurements that have generally <br /> been observed at the site between 30 and 40 inches of water,AGE anticipates the influent air flow <br /> stream to be approximately 125-150 standard cubic feet per minute(scfin)utilizing a 3'Fz-horsepower <br /> vacuum blower. <br /> 837 Shaw Road,Stockton,California 95215 - <br /> Telephone(209)467-1006 FAX(209)467-1118 <br />