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YABLE 1 -CHECKLIST OF REQUIRED DATA r
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES ,
<br /> Site Nanie and Location: . Earthgrains/Sara Lee/Kilpatrick,.1717 S. Center St:Stockton,San Joaquin County(RB#390801)
<br /> Y 1. Distance to production wells for municipal, domestic, ' A 2002sensitive receptor survey reported six water supply
<br /> agriculture, industry and other uses within 2000 feet of the wells.(nearest 1,750'northeast)within 2,000'of the Site.
<br /> The wells are not threatened by this release. I
<br /> site.,
<br /> Y 2. Site maps, to scale, of area impacted showing locations of any former. In 1.2-90, one 1,000-gallon gasoline UST was
<br /> and existing tank systems, excavation contours and.sample locations, removed.
<br /> boring and monitoring well elevation contours, gradients, and nearby
<br /> surface waters, buildings, streets,.and subsurface utilities;
<br /> Site lithology consists of clay, silt,and sand to "
<br /> Y 3, Figures depicting iithology(cross section), treatment system diagrams;., 67', the total depth investigated.
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal Approximately 18 yds.a of excavated soil was-transported to
<br /> uantit Forward Landfill in Manteca. '
<br /> Pae;
<br /> 5. Monitoring wells remaining on-site, Fight(8)monitoring wells(MW-1 through MW-5 and MW-2A,MW-3A,.and MWi
<br /> and two(2)remediation-wells(SP-1 and VW-1)were properly destroyed on
<br /> 9124112. _+:
<br /> 6. Tabulated results of all groundwater Depth to groundwater variedfrom 22'bgs to 30'bgs. Groundwater flow direction .
<br /> varied from east,to southeast. Groundwatergradient varied from 0.001 ft/ft to
<br /> elevations and depths to water 0,005 ft/ft.
<br /> 7. Tabulated,resutts of all samplingA7l data adequately tabularized in'va`rious ieports, incidding closure report.-
<br /> and analyses.-
<br /> Detection
<br /> nalyses.Detection limits for confirmation
<br /> sampling
<br /> ❑Y ';Lead analyses
<br /> l7y 18. Concentration contours of contaminants found and.those remaining in Tke extent of the identified contamination is
<br /> soil and groundwater, and both on-site and off-site:- described in the available reports.
<br /> ElLateral and Vertical extent of soil contamination
<br /> Lateral and FYJVertical extent of groundwater contamination j
<br /> 9. lone of influence calculated and assumptions used for subsurface Soil vapor extraction(SVE)and air sparging
<br /> remediation system and the zone of capture attained for the soil and (AS)were the engineered remediation.
<br /> groundwater remediation system;
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<br /> 10.Reports 1 information ,QY Unauthorized Release Form ❑Y Qli(38) 7-99.to 10-10
<br /> �Y 'Well and boring logs
<br /> PAR ❑Y FRP Other. Closure Report(9-09),Response To Comments .
<br /> 3-11
<br /> Y 111.Best Available Technology(BAT)used or an'explan.ation USTs removal, SVE,AS,and natural attenuation.
<br /> for not using BAT; r
<br /> �r 12. ,Reasons why background wa'ar unattainable Residual soil and groundwater contamination remains. 4
<br /> BAT,-
<br /> y. --1,3.-Mass-balance-calcutation-of-substance-treated ' --Consultan- TPTP-H-as-4,413-lbs.-of-TP-H-remain-in-soil_and
<br /> versus that remaining; 26 lbs remain in groundwater. SVE-removed 190 lbs of TPH. i
<br /> Y
<br /> 14. Assumptions,parameters, calculations and A soil vapor survey was not required by the regulatory agency. Soil
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<br /> mode!used in risk assessments, and fate and failed Region 2 ESLs for direct exposure(DE)and gross
<br /> transport modeling; contamination'for TPHg and DE for Benzene at 35'bgs, which is
<br /> below typical worker depths. Consultant states site does not
<br /> represent a significant risk. Fate and transport(F&T)modeling
<br /> showed in 20 years plume would not exceed 80'at 1 ppb benzene
<br /> concentration and benzene mass was reduced to 0.1 kg.
<br /> Y 15. 'Rationale why conditions remaining at site will Soil and groundwater contamination reportedly are limited in
<br /> not adversely impact water quality, health, or other extent. Land use(commercial)is not expected to change in the
<br /> beneficial uses, and foreseeable future. Time to reach W4Gs estimated as 40 yrs. _
<br /> By: JLB Comments:in 12-90, one 1,000-gallon gasoline UST was removed at the subject site.Residual soil and
<br /> groundwater contamination remains.Based upon the limited extent of contamination reported iii soil and
<br /> Date: groundwater, groundwater leaching WQGs in a reasonable time frame, no foreseeable changes in future -
<br /> 11/29/20.12 land use(commercial), and minimal risks from groundwater,soil vapor and soil,Regional Board staff concur
<br /> with San Joaquin County's Closure Recommendation.
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