Laserfiche WebLink
{• <br /> INTRODUCTION <br />' This Report Project Status R ort of Groundwater Monitoring provides groundwater quality monitoring <br /> J <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," (Boyajnan & Ross, Inc [B&R], 1998) "Initial Subsurface <br /> Investigation of Petroleum Hydrocarbons," (MR, 1998), and the "Workplan for Additional <br /> Subsurface Site Investigation for Petroleum Hydrocarbons,"(Philip P Ross, R G Consulting <br /> Hydrogeolognst, January 10, 1999) implemented as approved by the San Joaquin County <br />' Environmental Health Division(SJCEHD) <br /> The work described in the Groundwater Monitoring section documents sounding and sampling <br />' activities conducted on October 22, 1999 <br /> The History of Site Work (beginning on page 2) summarizes previous work performed on the subject <br /> site, as do the tables hstmg 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 in 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 /> 1 approximately 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 and soil and groundwater sampling <br />' activities at Site 3,which is the subject of this report <br /> The site was formerly occupied by two 12,000 gallon tanks, identified on a SJCEHD inspection report <br />' as Tank #1 and Tank # 4, both of which contained unleaded gasoline The tanks were removed on <br /> February 16, 1988 by Stockton Service Station Equipment Co, Inc (SSSE) Approximately 180 <br /> cubic yards of soil were excavated vvnth the tanks to a depth of about 11 feet below surface grade <br />' (bsg) Presently,the area over the former tanks and excavation is covered with concrete A survey of <br /> domestic, municipal, agricultural, industrial and other supply wells within a 2,000-foot radius of the site <br /> was conducted No municipal or drinking water supply wells were identified within the 2000-foot <br />' 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 /> Tertiary age, which in turn overlie crystalline basement rocks (Bartow and Nilsen, 1990) Data from <br /> 1 <br /> nst 51te3 gtrZ 99 doe i <br />