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1 <br /> ' INTRODUCTION <br /> This Project Status Report of Groundwater Monitoring provides groundwater quality monitoring <br />' information and data for gasoline impact from 2 former 12,000-gallon USTs The groundwater <br /> monitoring activities discussed herein were conducted in general accordance with the "Workplan for <br /> Initial Subsurface Investigation," (Boyajean & Ross, .Inc [B&R], 1998) `Initial Subsurface <br />' Investigation of Petroleum Hydrocarbons," (B&R, 1998), and the "Workplan for Additional <br /> Subsurface Site Investigation for Petroleum Hydrocarbons,"(Philip P Ross, R G Consulting <br /> Hydrogeologist, January 10, 1999) implemented as approved by the San Joaquin County <br />' Environmental Health Invision(SJCEHD) <br /> The work described in the Groundwater Monitoring section documents sounding and sampling <br />' activities conducted on September 14,2000 <br /> The History of Site Work (beginning on page 2) summarizes previous work performed on the subject <br />' site, as do the tables listing well-sounding data, and groundwater sampling analytical results <br /> Previously-submitted documents by the Port of Stockton (Port), and earlier consultants present <br /> historical information m greater detail <br /> SITE SETTING <br /> The property is located at the central portion of the Port in the City of Stockton, San Joaquin County, <br /> California. (see Figure 1) This site, along with Site 2, has been identified by SJCEHD as "Site Code <br /> 1282-124" Site 2 was determined to require no further investigations by SJCEHD Site 3 is <br /> approxiniately 50 feet north of Port Road G and about 300 feet west of Port Road 14 (see Figure 1) <br /> Following is a description of the tanks, as well as excavation, soil, and groundwater sampling activities <br />' at Site 3,which is the subject of this report <br /> The site formerly contained two 12,000 gallon tanks, identified on a SJCEHD inspection report as <br />' Tank#1 and Tank#4, both of which stored unleaded gasoline The tanks were removed on February <br /> 16, 1988 by Stockton Service Station Equipment Co, Inc (SSSE) Approximately 180 cubic yards of <br /> soil were excavated with the tanks to a depth of about 11 feet below surface grade (bsg) Presently, <br />' the area over the former tanks and excavation is covered with concrete A survey of domestic, <br /> municipal, agricultural, industrial and other supply wells within a 2,000-foot radius of the site was <br /> conducted No municipal or drinking water supply wells were identified within the 2000-foot radius <br />' LOCAL HYDROGEOLOGIC SETTING <br /> The site is located on the Delta of the San Joaquin River, approximately 2 miles east of the confluence <br />' of the San Joaquin and Calaveras Rivers The subsurface geology consists of a thick sequence of <br /> alluvial deposits of late Tertiary to Holocene Age, overlying sedimentary rocks of Cretaceous to <br /> Ternary age, which in turn overlie crystalline basement rocks (Bartow and Nilsen, 1990) Data from <br /> nearby studies within the Port area indicate a soil profile to a depth of about 20 feet bsg consisting of <br /> ,t MW�s as 1 <br />