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BLE 1 -CHECKLIST OF REQUIRED DATA moo,
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Former Chevron Service Station#9-0557, 139 S. Center St., Stockton, San Joaquin County
<br /> (RB#390502)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2009 sensitive receptor survey reported no water
<br /> agriculture, industry and other uses within 2000 feet of the site. supply wells located within 2,000'of the Site.
<br /> LYS-12. Site maps, to scale,of area impacted showing In 4/90, one 5,000-gallon and two 10,000-gallon gasoline,and
<br /> locations of any former and existing tank systems, one 1,000-gallon waste oil USTs were removed.In 2/03, three
<br /> excavation contours and sample locations,boring 10,000-gallon gasoline and one 1,000-gallon waste oil USTs
<br /> and monitoring well elevation contours,gradients, were removed. Site maps and figures showing tank locations,
<br /> and nearby surface waters,buildings,streets,and excavations,building and residual pollutants were provided in
<br /> subsurface utilities; investigation reports.
<br /> Y1 3.Figures depicting lithology(cross Site lithology consists of clay,silt,and sand to 115', the total depth investigated.
<br /> section), treatment system diagrams; No treatment system was constructed.
<br /> N 4. Stockpiled soil remaining on-site The fate of the excavated soil was not discussed in the available reports.
<br /> or off-site disposal(quantity);
<br /> Y 5.Monitoring wells remaining on-site, Twelve(12)remaining monitoring wells(MW-3,MW-5 through MW-8,MW-13
<br /> ate; through MW-15,MW-15D,MW-16, MW-17,and MW-18SD2)and 4 ozone sparge
<br /> wells OS-1S/--1D through OS-4S/-4D will be property destroyed prior to closure.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 19'bgs to 47'bgs. Groundwater flow
<br /> elevations and depths to water; direction varied clockwise from south to southeast. Groundwater gradient
<br /> varied from 0.001 Wit to 0.009 ft(ft.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports including all analysis for waste
<br /> and analyses: oil analytes.
<br /> 0 Detection limits for
<br /> confirmation sampling
<br /> ❑Y Lead analyses
<br /> LyJ 8. Concentration contours of contaminants found and those remaining in The horizontal and vertical extent of the
<br /> soil and groundwater,and both on-site and off-site: petroleum pollution is confined to the
<br /> property limits.
<br /> Y❑Lateral and MVertical extent of soil contamination
<br /> FYI Lateral and ro Vertical extent of groundwater contamination
<br /> NI 9.Zone of influence calculated and assumptions used for subsurface Multiple technologies were pilot tested but
<br /> remediation system and the zone of capture attained for the soil and failed and additional remediation was not
<br /> groundwater remediation system; required by the regulatory agency,
<br /> 10.Reports/information❑Y Unauthorized Release FormFY] QMRs(88)3-91 to 8-12
<br /> QY Well and boring logs❑Y PAR ❑N FRP FY Other No Further Action Report, 7-12
<br /> YJ 11.Best Available Technology(BAT)used or an Leak was stopped by removing tank and piping, use of
<br /> explanation for not using BAT; additional cleanup technology was attempted but proved
<br /> unsuccessful after pilot testing for groundwater extraction,.
<br /> dual phas extraction,and ozone injection.
<br /> Unable
<br /> Reasons why background was/is not Soil pollution does not present a threat to human health and
<br /> UUnable usin BAT; groundwater pollution is predicted to be restored in 110 years.
<br /> Y 13.Mass balance calculation of substance treated Consultant estimated residual TPH mass as 7,700 lbs.
<br /> 7
<br /> versus that remaining; (1,240 gallons)in soil and 142 lbs. (20 gallons)in groundwater.
<br /> Y 14. Assumptions,parameters,calculations and Site passed LTCP.SWRCB UST Cleanup Fund recommended site
<br /> model used in risk assessments,and fate and closure. Consultant states site does not represent a significant
<br /> transport modeling; environmental or health risk.
<br /> Y 15. Rationale why conditions remaining at site will Soil and groundwater pollution is reportedly confined to the
<br /> not adversely impact water quality,health, or other property limits.Land use(commercial)is not expected to change
<br /> beneficial uses;and in the foreseeable future. WQGs will be reached by 2123.
<br /> Groundwater plume is stable and slowly decreasing in
<br /> concentration.
<br /> By: JLB Comments:In 4/90 and 2/03,multiple USTs were removed at the subject site.Based on the stable and
<br /> declining concentrations in groundwater,no foreseeable changes in future land use(commercial),and no
<br /> Date: risks from soil vapor and soil,Regional Board staff concur with San Joaquin County's Closure
<br /> 7/30/2013 Recommendation.
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