Laserfiche WebLink
l <br /> N, , �L 11Er, _11 <br /> � <br /> ' <br /> GROUND ZERO ANALYSIS, INC. <br /> q0 Al <br /> 1714 Mam Street <br /> Esealon,California 95320 <br /> Telephone (209) 838-9888 <br /> Faesunile (209)838-9883 <br /> August 19, 1999 <br /> g <br /> Ms Lori Duncan <br /> San Joaquin County Public Health Services <br /> Environmental Health Division <br /> 304 East Weber Avenue, Third Floor <br /> Stockton, CA 95202 <br /> Subject Workplan Addendum for Subsurface Investigation <br /> 640 N El Dorado Street, Stockton, California <br /> Site Code 1090 <br />. Dear Ms Duncan <br /> This letter report is submitted to present an addendum to the August 24, 1998 Workplan prepared <br /> by Ground Zero Analysis, Inc (Ground Zero) for a subsurface investigation at the subject site <br /> (Figure 1) <br /> BACKGROUND <br /> The site previously operated as an automotive sales and service center and utilized one 250- <br /> gallon UST for storage of waste oil The UST was removed under permit from PHS/EHD on <br /> March 26, 1997 A soil sample collected from beneath the tank contained elevated levels of <br /> petroleum hydrocarbons, lead, and chlorinated solvents Analytical results are summarized in <br /> Table 1 Groundwater beneath the site is expected to be encountered at approximately 25 to 30 <br /> feet below ground surface (bgs), based on historical information available from the San Joaquin <br /> County Flood Control and Water Conservation District and from previous work on the site <br /> The August 24, 1998 Workplan proposed a general scope of work consisting of drilling and <br /> sampling four soil borings in the vicinity of the former underground storage tanks (UST) to <br /> investigate the vertical and lateral extent of residual soil contamination, collecting a discrete <br /> groundwater sample from one boring to determine if groundwater has been impacted, and <br /> preparing a technical report that summarizes the methods and results of the investigation <br /> The initial investigation performed on January 19, 1999 determined that soil and groundwater in the <br /> vicinity of the former waste oil UST has been impacted by petroleum hydrocarbon constituents and <br /> ti <br /> d'italgroundzelgabblyd\W Paddndm doc <br />