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Phase I Environmental Site Assessment
<br /> City of Stockton Multi-Modal Station/Shopping Center
<br /> Page 13
<br /> On March 25, 1987, two approximately 7,500-gallon USTs were removed from the site The USTs had
<br /> t { stored diesel and product oil in the past The diesel tank was noted as having 2-inch diameter holes on the
<br /> lie sides One soil sample was collected from beneath each of the tanks In a letter dated December 20, 1988,
<br /> Cynthia Wagner of San Joaquin County requested lab results from the tank removal A lab report dated
<br /> January 17, 1989 was submitted to PHS/EHD with the following results The sample from beneath tank
<br /> #1 indicated the presence of total xylenes, total petroleum hydrocarbons quantified as gasoline (TPH-G),
<br /> and C9-C36 (seri-volatile hydrocarbons) at concentrations of 1,900 micrograms per kilogram (µg/kg),
<br /> 1 7 milligrams per kilograin (mg/kg), and 130 mg/kg, respectively No analytes were detected in the soil
<br /> sample collected from beneath tank#2
<br /> In a UST Unauthorized Release/Contamination Site Report dated January 19, 1989, it was noted that a
<br /> report on the tank removal had not been received and that further site assessment was required to
<br /> determine the nature and extent of contamination
<br /> According to an undated drawing from the Siebold Corporation, a 10,000-gallon UST and a 3,000-gallon
<br /> UST are located along E Channel Street, approximately 50 feet south of the north fence and 90 feet east
<br /> of the west fence
<br /> The site received "no further action" status on December 20, 1996 from the PHS/EHD Of the ten USTs
<br /> that were listed in the I985 document,removal documentation exists for only two
<br /> r
<br /> Site. Boeknnon & Woody
<br /> Address. 930 E Miner
<br /> A 1,000-gallon UST, which was used to store unleaded gasoline, was installed in 1983 and removed in
<br /> November 1993 Upon tank removal two soil samples were collected from the base of the excavation at
<br /> 11 feet below ground surface One sample was also collected from the excavated soil stockpile
<br /> Laboratory analytical results indicate that benzene, toluene, ethyl benzene,total xylenes,and TPH-G were
<br /> not detected in either sample from the excavation The soil sample collected from the stockpile indicated
<br /> the presence of total xylenes at a concentration of 16 tcg/kg The site received a "no further action"
<br /> notification on December 17, 1993
<br /> 4.2 1.2 Off-Site Property Records Review
<br /> 4.2.1.2 1 Locations 0-100 feet from the site
<br /> Larry's Auto Repair
<br /> i 308 N. Grant Street, Stockton, CA
<br /> First Quarter 2000 Quarterly Report, dated May 3, 2000
<br /> Groundwater monitoring activities were conducted on February 16, 2000 MW-2 was inaccessible due to
<br /> flooding The average depth to water was approximately 313 feet The well screens for MW-1, MW-3,
<br /> MW-4, VW-2B, VW-5C, MW-7, VW-3, and VW-4 were drowned by approximately 2 to 23 feet of
<br /> water The groundwater gradient is to the east-southeast TPH-G was detected in the samples from all of
<br /> the wells at concentrations ranging from 220 to 170,000 µg/L Benzene was also detected in all of the
<br /> wells at concentrations ranging from 4 4 to 30,000 p.g/L TPH-D was detected in the groundwater sample
<br /> from MW-4 at a concentration of 7,300 jig/L 1,2 DCA was detected in the samples from MW-3, MW-7,
<br /> and VW-2B at concentrations of 2 1, 14, and 1,300 gg/L, respectively The concentrations of
<br /> hydrocarbons have in general been decreasing slightly as the depth to groundwater decreases TPH-G has
<br /> been found as high as 200,000 gg/L, benzene as high as 56,000 gg/L, and TPH-D as high as 55,000 µg/L
<br /> Advanced Geo Environmental, Inc, recommended feasibility testing and the installation of additional
<br /> monitor wells, as well as continued groundwater monitoring
<br /> ' {�� CONDOR
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