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CaliforniqVegional Water Quality Co&ol Board
<br /> Central Valley Region
<br /> Karl E. Longley,ScD,P.E.,Chair P
<br /> ! Linda S.Adams Arnold
<br /> Secretaryfor 11020 Sun Center Drive 4200,Rancho Cordova,California 95670-6114 Schwarzenegger
<br /> Environmental Phone(916)464-3291 -FAX(916)464-4645
<br /> Protection http://www.waterboards.ca.gov/centralvalley Governor
<br /> TO: Jim Munch FROM: Jim Barton
<br /> Senior Water Resources Control Engineering Geologist
<br /> Engineer Underground Storage Tanks
<br /> RECE��E� Enforcement Unit II
<br /> DATE: 9 July 2009 SIGNATURE:
<br /> JUL 17 2009
<br /> ENV� ��EIIR��O��N����MENTTR HEALTH
<br /> SUBJECT: CLOSURE , NE G
<br /> II�fEMOABBARD, INC, 640 N. ELDORADO STREET,
<br /> STOCKTON, SAN JOAQUIN COUNTY (RB CASE #391005)
<br /> Background
<br /> The subject site (Site) is currently a vehicle repair and aftermarket parts business that formerly
<br /> operated as a Lincoln-Mercury and Honda new car dealership with a service bay for repairs
<br /> (enclosed Figures 1 and 2). On 26 March 1997, one 250-gallon waste oil underground storage
<br /> tank (UST) was removed from the service bay within the building at the Site. The San Joaquin
<br /> County Environmental Health Department (SJCEHD) observed evidence of a release of
<br /> petroleum hydrocarbons to soil beneath the UST. The maximum soil confirmation results were
<br /> reported as total petroleum hydrocarbons (TPH) as diesel (TPHd), 8,200 milligrams per
<br /> kilogram (mg/kg); TPH as gasoline, 51 mg/kg; ethylbenzene, 17 mg/kg; xylenes, 90 mg/kg;
<br /> tetrachloroethene (PCE) 2.6 mg/kg, and lead, 4,000 mg/kg.
<br /> On 2 June 1998, the SJCEHD placed the Site in the Local Oversight Program and requested an
<br /> investigation. The 20 May 1999 Subsurface Investigation Summary Report reported the
<br /> following maximum soil borings results: TPHg, 1,800 mg/kg; TPHd, 4,600 mg/kg; total
<br /> recoverable petroleum hydrocarbons (TRPH), 8,300 mg/kg; benzene, 4.6 mg/kg; toluene,
<br /> 35 mg/kg; ethylbenzene, 11 mg/kg; xylenes, 61 mg/kg; naphthalene, 39 mg/kg; and total lead,
<br /> 3,500 mg/kg. Grab groundwater.maximum concentrations were TPHg, 4,500 micrograms per
<br /> Liter (ug/L); TPHd, 510,000 ug/L; TRPH, 16,000,000 ug/L; benzene, 180 ug/L; toluene,
<br /> 640 ug/L; ethylbenzene, 110 ug/L; xylenes, 570 ug/L; naphthalene, 680 ug/I;
<br /> cis-1,2-dichloroethene (a PCE breakdown or daughter product), 32 ug/L; and
<br /> total lead, 95 ug/L. Five additional soil borings were advanced in October 1999 and four
<br /> monitoring wells (MW-1 through MW-4) were installed in December 2000. Maximum
<br /> groundwater monitoring concentrations In December 2000 for MW-3 (former tank pit) were
<br /> TPHg, 14,000 ug/L; TPHd, 4,400 ug/L; TPH as oil and grease (TPHo&g), 98,000 ug/L;
<br /> benzene, 61 ug/L; toluene, 300 ug/L; ethylbenzene, 96 ug/L; and xylenes, 420 ug/L; also
<br /> detected were PCE, 29 ug/L; and trichloroethene (TCE, a PCE daughter product), 3.3 ug/L in
<br /> MW-1 (downgradient of the UST). Total lead, fuel oxygenates and lead scavengers were not
<br /> detected in groundwater.
<br /> California Environmental Protection Agency
<br /> ff Recycled Paper
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