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California R..,oional Water Quality ',_,3ntrol Board
<br /> Central Valley Region
<br /> z�
<br /> Peter M.Rooney Sacramento Main Office Ed J.Schnabel
<br /> Secretaryfor Internet Address: http://www.swrcb.ca.gov/--rwgcb5/home.html Chair
<br /> Environmental 3443 Routier Road,Suite A,Sacramento,California 95827-3003
<br /> Protection Phone(916)255-3000-FAX(916)255-3015
<br /> TO: Gordon L. Boggs FROM: Mark R. List
<br /> DATE: 6 July 1998 SIGNATURE: f�
<br /> SUBJECT: REVIEW FDR NO FURTHER ACTIONREQUIRED, FIRE STATION#9,
<br /> 550 E IIARDING WAY,STOCKTON,SAN JOA QUIN COUNTY
<br /> In response to the 27 May 1998 letter from the San Joaquin County Environmental Health Division,
<br /> LOP/Site Mitigation Unit, requesting written comments on the completion of the site investigation and
<br /> remedial action of contamination, I have noted the following:
<br /> Background: On 7 November 1990, one 550-gallon diesel fuel UST was removed from the site. Soil
<br /> samples collected from the tank pit at a depth of 12 feet below grade, at the time of tank removal
<br /> activities, did not indicate the presence of petroleum hydrocarbons at concentrations above the
<br /> laboratory reporting limits. One additional soil sample, collected beneath the product delivery line, at
<br /> five feet below grade, was analyzed, and detected minor contamination.
<br /> On 23 December 1996, at the request of the San Joaquin County Environmental Health Division, three
<br /> direct push borings, SP-1, SP-2, and SP-3, were advanced to depths of 47.5, 20 and 20 feet,respectively,
<br /> below ground surface. Soil samples were collected at 5, 12, 16, and 20 feet bgs in boring SP-1, from 12,
<br /> 16 and 20 feet bgs in boring SP-2, and from 12 and 16 feet bgs in boring SP-3, and analyzed for BTEX,
<br /> MTBE, and TPHd. Following are the results:
<br /> SP-1, at 5 feet and 12 feet bgs, contained TPHd at concentrations of 31 and 310 mg/Kg,
<br /> respectively. Both samples were collected within the area of the former tank excavation and
<br /> presumably from the tank backfill material.No other analytes were detected above the laboratory
<br /> detection limits (LDL).
<br /> SP-2, at 16 feet bgs, contained toluene at 0.01 mg/Kg, ethylbenzene at 0.01 mg/Kg, xylene at
<br /> 0.07 mg/Kg, and TPHd at 24 mg/Kg. No other analytes were detected above the LDL.
<br /> SP-3, no analytes were not detected above the LDL.
<br /> California Environmental Protection Agency
<br /> C4 Recycled Paper
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