Laserfiche WebLink
, <br /> CHAPTER 2 <br /> T <br /> SITE INVESTIGATION MSTORY <br /> The following history has been compiled from information presented in previous <br /> Nachant Environmental Inc. (NEI), Tank Protect Engineering of Northern California, Inc. <br /> (TPE), and Hydro-Environmental Technologies, Inc. (HETI) reports (identified below) <br /> prepared for E-Z Serve Petroleum Marketing Company of California (E-Z Serve) for their <br /> 1 Former Station #100966, located at 2537 Waterloo Road in Stockton, California (Site) <br /> Previous Site Investigations <br /> 1 <br /> According to NEI's November 22, 1991, Preliminary Site Assessment Report, one - <br /> 8,000-gallon and three 10,000-gallon on-site, single-walled, steel, underground storage tanks <br /> (USTs), containing regular leaded, regular unleaded, and premium unleaded fuel, existed <br /> beneath the property until March 1990. The date which these tanks were installed is <br /> unknown The four USTs, associated underground piping, and fuel dispensers were removed <br /> from the Site during March 1990 Petroleum hydrocarbon constituents were identified in the <br /> soil beneath the 8,000-gallon UST and beneath the fuel island Based on those results, the <br /> San Joaquin County Public Health Services Department, Environmental Health Division <br /> required E-Z Serve to perform a preliminary site assessment <br />' NEI supervised the drilling of three soil borings to depths of approximately 40 and <br /> 50 feet below ground surface (bgs), in the vicinity of the tank backfill area, during August <br /> 1991. Identifiable concentrations of total petroleum hydrocarbons as gasoline (TPHg) and <br />' benzene, toluene, ethylbenzene, and xylene isomers (BTEX) were present in the three borings <br /> The highest concentrations of petroleum hydrocarbon constituents were identified in a soil <br /> sample'collected from Boring B-1, located in the center of the former UST area. Groundwater f <br /> was not encountered during this investigation <br />� TPE installed five on-site groundwater monitoring wells(Wells MW-1 through MW-5), <br /> to depths of approximately 90 feet bgs; between June 11 and July 14, 1992, at the locations <br /> shown on Figure 2-1 Groundwater was encountered during this investigation at a depth of <br /> approximately 81 feet bgs Results of laboratory analyses performed on the soil and <br /> groundwater samples collected during this investigation identified TPHg and BTEX in the soil <br /> and groundwater samples collected from the five soil bonngs/monitonng wells Results of <br /> Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this <br /> document <br /> 05118/9S1E%REPQRTS115671100466WHAP ZWP5 <br /> QMS-P5410 <br />