Laserfiche WebLink
4; RIIN <br /> 1 .0 INTRODUCTION <br /> I <br /> Bridgestone/Firestone, Inc (BFS) has retained Orion Environmental Inc (Orion) to conduct <br /> groundwater assessment activities at the former BFS facility at 400 North EI Dorado Street <br /> in Stockton, California (the site, Figure 1) This document summarizes the work planned <br /> to delineate the nature and extent of impacted groundwater at the site and has been <br /> prepared in response to a letter from the San Joaquin County Environmental Health <br /> Division (SJCEHD) dated 30 August 1999 <br /> 1.1 Background <br /> The site 1s the former location of an automobile gasoline station that operated during the <br /> 1920s and 1930s After this period the site was used as a retail tire and automobile <br /> service center In 1967, four underground storage tanks (USTs) were closed in place by <br /> filling the tanks with sand In 1991 , one of these previously closed tanks was removed <br /> . from the site along with eleven other USTs previously located at the site The size of the <br /> remaining tanks are reported as follows Tanks 1 and 3 are 7,500 gallon capacity and <br /> Tank 2 is 550 gallons <br /> In May 1997, four slant borings were drilled in the vicinity of the three remaining USTs <br /> by Foothill Engineering Total petroleum hydrocarbons as gasoline (TPHg) were detected <br /> in soil samples beneath tank #3 at concentrations up to 16,200 milligrams per kilogram <br /> (mg/kg) No groundwater samples were collected during this investigation <br /> In December 1998, soil borings BFS-1 and BFS-2 were drilled in the vicinity of the three <br /> closed-in-place USTs by QST Environmental (QST) Figure 2 shows the boring locations <br /> Groundwater was encountered in these borings at approximately 28 feet below grade <br /> Groundwater from boring BFS-1 contained detected concentrations of TPHg of <br /> 4,200 micrograms per liter (µg/I) and benzene, toluene, ethylbenzene, and xylenes (BTEX) <br /> of 220 µgj, 400 µgj, 340 µg/l, and 1,500 gg/I, respectively MTBE was also detected in <br /> groundwater from boring BFS-1 at a concentration of 0 78 µg/I Of the gasoline-related <br /> compounds listed above, only xylenes were detected in a groundwater sample obtained <br /> from boring BFS-2 (0 55 4g/1) <br /> S\BFS\STOCKTON\WKP0p1 DOC 10/27/99 1 -1 <br />