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LE 1 CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> ;Site:N�amedLocation: Former Canteeri�Corpbration;1500 North Shaw Rd., Stockton, San Joaquin County(RB#390730)
<br /> ? Distance to production wells for munici al, domestic; An updated 2092 sensitive receptor survey reported four p 'i domestic water supply wells{592'southeast, 9,000
<br /> agriculture, industry and other uses within 2000 feet of the southwest, 1,800'northwest,and 1,900'northwest)within
<br /> site. ' 2,000'of the Site. The wells are not threatened by this
<br /> s
<br /> release.
<br /> Y 2. Site maps, to scale, of area impacted showing locations-of any former In 3-92, one 10,000-gallon gasoline UST was
<br /> and existing tank systems, excavation contours and sample locations, removed., i
<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 lithology(cross section),treatment system diagrams; 121,, the total depth investigated.
<br /> y �}. Stockpiled soil remaining on-site or ofF-site disposal Approximately'72 y excavated soil was excavated and
<br /> p g it -€ transported to Forward Landfill in Manteca.
<br /> uanti MW-3A MW-30,
<br /> Y 5. Monitoring wells remaining on-site, fate; Twenty one(21)monitoring wells(MW-1 through MW-13,
<br /> ';MW- 93A, MW-13B, MW-14 M through MW-15M, MW-14D through MW-15D)
<br /> and eighteen(18)remediation wells(AS-1 through AS-13, and VE-1 through
<br />- ?3 VE-5 will be ro er! des tro
<br /> ed.
<br /> T 8. Tabulated results of all ground=ter'
<br /> epth to groundwater varied from 34'bgs to 78'bgs. Groundwater flow direction
<br /> elevations and de the to water, aned from south to southwest of a gradient of 0.0019 ft/ft to 0.0035 ft/ff.
<br /> 7a
<br /> . Tbulated results of all sampling ,All data adequately tabularized in various reports, including closure report,
<br /> and analyses:
<br /> Detection limits for confirmation
<br /> sampling
<br /> QY Lead analyses #
<br /> 77 1 8. Concentration contours of contaminants found and those remaining in The extent of the identified contamination is
<br /> soil and groundwater, and both on-site"and off-site: described in the available reports:. '
<br /> Lateral and Y Vertical extent of soil contamination
<br /> Lateral and Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface Soil vapor extraction(S VE)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; ,]
<br /> 10.Reports I information QY Unauthorized,Release Form n QMRs(38) 6-93 to 11-11
<br /> .E
<br /> n Well and boring logs PAR .� FRP ❑y Other .Closure Report!(9-11)',
<br /> Y J 11.Best Available Technology(BAT)'used or an'explanation USTs removal, over-excavation, SVE(AS,and natural
<br /> for not using BAT; .I attenuation.
<br /> 12. Reasons why background was is unattainable Residual soil and groundwater contamination remains on-site.
<br /> i— Y -BAIT, _
<br /> ice treated 'Consultant estimated TPH mass removed as 13,711 lbs in soil and
<br /> Y 13.Mass balance calculation of subsfar
<br /> versus that remaining; j 46 lbs in groundwater.Approximately 6,257 lbs TPH remain in soil
<br /> -and 6 lbs TPH remain in groundwater..
<br /> Y 14. Assumptions, parameters, calculations and. Soil vapor not sampled due to distance(40)to building. Prior to
<br /> model used in risk assessments, and We and SVE,soil failed Region 2 ESL for direct contact(benzene, toluene,
<br /> transport modeling; ' ethylbenzene,xylenes)and gross contamination(toluene,xylenes)
<br /> at 14'bgs, which is below typical worker depth. Consultant states
<br /> site does not represent a significant risk:
<br /> Y115. Rationale why conditions remaining at site will ''Soil and groundwater contamination reportedly are limited in
<br /> not adversely impact wafer quality, health, oriother .extent. Groundwater plume is stable and decreasing. Land use
<br /> beneficial uses;and " '(commercial)is not expected to change in the foreseeable future.
<br /> =.TPH in roundwater is estimated to reach WQGs in 2020.
<br /> By, JLB. Comments:In 3-92, one 10,000-gallon gasoline UST was removed at the subject site. Residual soil and
<br /> groundwater contamination remains on-site. Based upon the limited extent of contamination reported in soil
<br /> Date: and groundwater,a stable groundwaterplume with declining concentrations, no foreseeable changes in
<br /> 7/18/2012 future land use(commercial),and minimal risks from soil vapor,soil and groundwater, Regional Board staff
<br /> concur with San Joaquin"County's Closure Recommendation. .
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