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<br /> 1.0 INTRODUCTION/SI'Z'E HISTORY
<br /> This report is being submitted to the San Joaquin County Public r
<br /> n. Health Services, Environmental Health Division to further define ;,
<br /> soil and groundwater contamination beneath the Weber Poiret t k.
<br /> property, 141 N. El Dorado Street, Stockton, California (Figure
<br /> 3 In 1955, the Shell Oil Company constructed a gasoline and serviceIVY
<br /> , � .
<br /> •:Jf # station at 141 North El Dorado Street in Stockton. This construe-
<br /> tion included the installation of four 4,000-gallon underground) ,5.�,
<br /> storage tanks (UST) used to store ,leaded gasoline dispensed fr. .� ,
<br /> " two islands, and one 500-gallon UST used to store waste
<br /> to disposal. In 1963, one of the 4,000-gallon USTs was removed A; {
<br /> °. .
<br /> + and two 7,500 gallon USTs were installed to store unleaded gaso
<br /> 'd line. The station discontinued selling gasoline in 1981 and all
<br /> r'. five of the gasoline USTs were removed. No soil samples ware �4 E
<br /> collected and analyzed at the time of the tank removal. The USTg . ..
<br /> :.excavation was backfilled and paved to grade. The waste oil UST ,.
<br /> .. . ;r remained on the site and was in use until June of 1990.. !
<br /> .. In Soptember of 1989, ERM west of Sacramento, California!,conduct-
<br /> ed a Phase I Environmental Site Assessment of the pz'operty.
<br /> [ � ; During the site assessment, soil testing within the fornoer, gaso-
<br /> r Mine UST excavation and a tank test of the existing waste oil UST
<br /> �. >jwas recommended (ERM, Phase I, Environmental' Site Assessment, " }
<br /> :3 Sept. 1989). i
<br /> ,. w
<br /> On May 30, 1990, Kleinfelder, Inc. conducted a soil vapor survey ;*
<br /> around the former gasoline tank pit and islands, and found de- k
<br /> , 3 tectable levels, of gasoline constituents -in and around the former LL
<br /> UST excavation.
<br /> u ;� d6' Kleinfelder, Inc. also performed a precision tank teat on the
<br /> waste oil UST on June 1 1990. The tank failed the test and on
<br /> June 5, 1990, the contents of the waste oil tank were removed and ;
<br /> } r � r9 sg disposed of off-site. The tank inlets were upped and ''jthe tank " ; fl
<br /> ; is no longer being used to store waste oil. (Kleinfel'der Soil
<br /> Gas and Storage Tank Asswssmer�t, June 14, 1990).
<br /> I
<br /> :' On September 5 and 6, 1990, an additional phase of site iinvrteati-
<br /> ad ; gation was performed by Leedshill-Herkenhoff, Inc. Soil samples
<br /> were collected for laboratory analysis from eight, 6-inch, hoi- r
<br /> 9
<br /> ,flow-stem Augured boreholes, within and adjacent to the excavated � f
<br /> area of the former gasoline USTo and the existing waste "',oil UST. r
<br /> on September 20 and 21, 1990, three monitoring wells were in-
<br /> c,- stalled at the site. On October 2, 1990, static depth '+eo'water j
<br /> data and water samples for laboratory analysis were collected F
<br /> from the monitoring wells. Both soil and groundwater contamina-
<br /> ° ° ' � " tion was detected during the investigation (Preliminary Site
<br /> .¢
<br /> ;' Assessment Report, Oct. 23, 1990, Leedshill-Herkenhoff, Inc. )
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