ARCHIVED REPORTS XR0006976 - Laserfiche WebLink

Home Browse Search

i 1.0 EXECUTIVE SUMMARY Stratus Environmental, Inc (Stratus), on behalf of A Teichert and Sons, Inc (Teichert), has prepared this Site Conceptual Model and Subsurface Investigation Report (SCM) for the Teichert property located at 103 North E Street, Stockton, California (see Figures 1 and 2) This SCM was prepared pursuant to a request from San Joaquin County Environmental Health Department (SJCEHD) for additional characterization of the extent of 1,2 dichloroethane (1,2-DCA) impact and refinement of the SCM' ' The site is a vacant property situated in a predominantly industrial neighborhood in south Stockton Gasoline, diesel fuel, and waste oil were formerly stored in underground storage tanks (USTs) at the site Subsurface petroleum hydrocarbon impact was discovered following failure ' of a gasoline UST tank tightness test in February 1986 All of the USTs have been removed from the site ' Between December 1986 and March 1994, 25 exploratory soil borings were advanced to characterize petroleum hydrocarbon impact beneath the site Eleven of the borings were converted to groundwater monitoring wells The groundwater monitoring wells were ' constructed to significantly variable depths, as groundwater levels have fluctuated between approximately 37 feet below ground surface (bgs) (1987) and 81 feet bgs (1992) during historical groundwater monitoring Three groundwater monitoring wells (MW-1, MW-13, and MW-14), a . soil vapor well (VW), and an air sparge well (AS-1) remain beneath the site All other wells have been properly abandoned with SJCEHD concurrence ' Several phases of remedial action have been implemented at the site (soil excavation [1986 and 1999], soil vapor extraction [SVE] and concurrent SVE with air sparging [1994 and 1995], and bioventing [2005 and 2006]) Approximately 13,400 pounds of total petroleum hydrocarbons as ' gasoline (TPHG) have been removed from the subsurface Less than 50 pounds of TPHG are estimated to remain in groundwater beneath the site Concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX), and methyl tertiary butyl ether (MTBE) are currently very ' low to non-detectedable Stratuspreviously requested No Further Action Required (NFAR) status for the subject ' property 2'3 SJCEHD has denied closure of the environmental case, citing elevated levels of 1,2-DCA in groundwater, and directed that the lateral and vertical extent of the 1,2-DCA impact to groundwater be further characterized ' Between January 23 and 29, 2006, Stratus advanced nine cone penetrometer test (CPT) borings to depths ranging from approximately 85 to 150 feet bgs This )Investigation consisted of ' profiling subsurface soil types at each of the CPT locations using an electronic piezocone, followed by depth discrete groundwater sampling in a separately advanced boring at each ' Letter dated July 29, 2005 z Final Closure Report, dated July 20, 2001 ' a Additional Information to Support Closure,dated January 25,2002 K\Teichert\Stockton-1031Repartslscm 04-2006 doc Page 1 OMAWO