ARCHIVED REPORTS_XR0012626 - Laserfiche WebLink

Home Browse Search

Problem Assessment Report Underground Fuel Storage Tank Site investigation y 1.0 INTRODUCTION This Problem Assessment Report presents the results of a soil and shallow groundwater investigation program as recommended in the ROY F. WESTON, INC. , (WESTON) September 7, 1988 Preliminary Report for the San Joaquin County Human Services building site FA located at the intersection of San Joaquin Avenue and Washington Street in Stockton, California (Figure 1) . The site activities included the installation and sampling of three shallow groundwater monitoring wells and the gathering and analysis of soil samples from fifteen locations. All of these activities occurred with the one block construction area with focus being on the southeast corner of the site. from which nine i E.�. fuel storage tanks had been previously removed. All of the work within this report was conducted under the supervision of a California registered geologist. 2.0 BACKGROUND During the time period of April through May 1988, a total. of nine .`: underground fuel storage tanks were removed from the southeast corner of the Hzxman Services Agency construction site in downtown Stockton. The nine tanks were residual tanks from a gasoline service station which had previously been located at the site. The tanks consisted of two unleaded gasoline tanks, three leaded gasoline tanks, one waste oil tank and three sand filled aban- doped tanks. The locations of these tanks within the construc- tion site are shown on Figure 2. After each tank removal, the soils beneath the tank were sampled and analyzed for various analytical parameters. The analytical results for the soil samples taken from beneath some of the tanks revealed significant concentrations of total petroleum hydro- carbons (TPH) . Additionally, concentrations of volatile com- pounds associated with gasoline (Benzene, Toluene, Xylene & Ethylbenzene (BTX&E) ) where found to be above San Joaquin county Health acceptable limits. (Table 1) . In September 1988, a Preliminary Report covering the tank removal program and outlining the recommended scope of work necessary to develop a Problem .Assessment Report was prepared. In December 1988, the activities detailed within the scope of work were implemented.