Laserfiche WebLink
URS <br /> • February 24, 2005 <br /> Mr Harlin Knoll 0 02093 <br /> San Joaquin County Environmental Health Department [� ��] ��� 06 a3 <br /> 304 E Weber Street, Third Floor <br /> Stockton, California 95202 <br /> Re: Site Closure Report P EPd 111 ri pNM <br /> ARCO Service Station 2093 PEPMjT%F 1fjCFS T1� <br /> 3425 Tracy Boulevard,Tracy, California <br /> Dear Mr Knoll <br /> URS Corporation Americas (URS), on behalf of Atlantic Richfield Company (ARCO — a BP-affiliated <br /> company), has prepared this site closure report for the ARCO Service Station and AM/PM mini-mart <br /> No 2093 located at 3425 Tracy Boulevard, Tracy, California(site) <br /> This report contains the following information site background, remediation, contaminant mass <br /> remaining and distribution, sensitive receptors, and conclusions and recommendations <br /> SITE BACKGROUND <br /> Currently, the site is operated as an ARCO gasoline service station and AM/PM mini-mart convenience <br /> store The site is located at the northwestern corner of the intersection of Tracy Boulevard and West <br /> Clover Road (Figures 1 and 2) The site is bounded by commercial property to the west and north, Tracy <br /> Boulevard to the east, and West Clover Road to the south Most of the site is paved <br /> Site structures include double-walled, fiberglass underground storage tanks (USTs) for gasoline, two <br /> pump islands, and the AM/PM mini-mart Site monitoring/investigation began in April 1987 Twelve <br /> groundwater monitoring wells (ATR-1 through ATR-12), seven soil vapor extraction (SVE) wells <br /> (VES-1 through VES-7), three air sparging (AS) wells (S-1 through S-3), one groundwater monitoring/ <br /> AS well (SMW-1), and one groundwater extraction well (TEX-1) have been installed at the site The <br /> groundwater extraction well was properly destroyed by URS on January 26, 2004, under direction of the <br /> San Joaquin County Environmental Health Department Since 1987, the site has been on a quarterly <br /> groundwater monitoring schedule An SVE/AS system was operated at this site to remediate impacted <br /> soil and groundwater Tabulated results of the groundwater monitoring efforts are presented in Tables 1, <br /> 2, and 3 <br /> Site Geologyand H dro Bolo <br /> Y 9 9Y � <br /> As a result of drilling activities at the site, the subsurface geology has been documented to a total depth <br /> of approximately 35 feet below ground surface (bgs) The subsurface geology is dominated by alluvial <br /> sediments consisting of interbedded mixtures of sand, silt, and clay From the ground surface to <br /> approximately 8 feet bgs is a relatively continuous layer of sandy clay Below this interval, silt <br /> dominates the lithology to a depth of approximately 20 feet bgs This silt-dominated interval is underlain <br /> URS Corporation <br /> Crown Corporate Center <br /> 2870 Gateway Oaks Drive, Suite 300 <br /> Sacramento CA 95833 <br /> Tel 916 679 2000 <br /> Fax 916 679 2900 K 1WprocessU5 BP ARCO\020931Closure Report0raft of 2093 Closure Report doc <br />