Laserfiche WebLink
y <br /> SECOR vvww.secor.corn <br /> INTERNATIONAL 3017 Kilgore Road,Suite 100 <br /> S E C O R INCORPORATED Rancho Cordova,CA 95670 <br /> 916-861.0400 Tcr <br /> 916-861-0430 FAx <br /> March 29, 2004 RECEIVED <br /> Ms. Vicky McCartney APR 0 1 2004 <br /> San Joaquin County Environmental Health Division ENVIRONMENT HEALTH <br /> 304 East Weber Avenue, Third Floor PERMR/SERVICES <br /> Stockton, California 95202-2078 <br /> RE: Addendum to Revised Interim Remedial Action Plan and Work Plan for <br /> Ozone Sparge Well Installation and Additional Off-Site Assessment <br /> ConocoPhillips (Former BP) Service Station No. 11193, <br /> 3202 West Hammer Lane <br /> Stockton, California <br /> SECOR Project Nos.: 77BP.60193.01.0147/ <br /> 77C P.60193.01.0002 <br /> Dear Ms. McCartney: <br /> This letter, prepared by SECOR International Incorporated (SECOR) on behalf of ConocoPhillips, <br /> presents an addendum to SECOR's Revised Interim Remedial Action Plan and Work Plan for Ozone <br /> Sparge Well Installation and Additional Off-Site Assessment, dated September 15, 2003. This work <br /> plan addendum is submitted in response to a San Joaquin County Environmental Health (SJCEHD) <br /> letter dated December 23, 2003 (Attachment 1), which requested further evaluation of the vertical <br /> extent of impacted groundwater at the Site. The proposed scope of work will consist of an initial <br /> phase of Cone Penetrometer (CPT) borings to define subsurface stratigraphy below 50 feet below <br /> ground surface (bgs) and a second phase of HydroPunch® sampling at the CPT locations to <br /> evaluate potential dissolved phase contamination in deeper groundwater bearing zones. <br /> In addition, as recommended by the SJCEHD in their December 23, 2003 letter, SECOR will <br /> complete off-site assessment activities, as proposed in SECOR's September 15, 2003 Revised <br /> Interim Remedial Action Plan and Work Plan for Ozone Sparge Well Installation and Additional Off- <br /> Site Assessment, by continuously coring the soil borings for the two proposed off-site wells to the <br /> total depth explored. In addition, at the request of the SJCEHD, soil and groundwater samples <br /> collected during off-site assessment activities will also be analyzed for the presence of total <br /> petroleum hydrocarbons as diesel (TPHd) by EPA Method 8015M, and other fuel oxygenates <br /> including tertiary amyl methyl ether (TAME), di-isopropyl ether (DIPE), ethyl tertiary butyl ether <br /> (EtBE), tertiary butyl alcohol (TBA), ethanol, 1,2-dichloroethane (1,2-DCA), and ethylene dibromide <br /> (EDB) by EPA Method 8260B (single run). Following the completion of subsurface investigation <br /> activities described in the September 15, 2003 work plan for off-site assessment and this work plan <br /> addendum, SECOR will determine whether additional groundwater monitoring wells are necessary to <br /> further define the lateral and vertical extent of dissolved petroleum hydrocarbons and fuel <br /> oxygenates. <br /> A brief discussion of site background, proposed scope of work, and a schedule are presented below. <br /> I:1ConocoPhillips1111931Work Plans\[RAP&Off-Site Asmt WP Addendum v 2.doc <br />