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*MBLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Jay's Mini Mart, 3302 West Lane, Stockton San Joaquin County(RB#391043)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2008 sensitive receptor survey stated one water supply
<br /> agriculture, industry and other uses within 2000 feet of the site, well is located 600'south;and one irrigation well and one
<br /> domestic well are located 1,100'and 1,600', respectively,
<br /> northwest of the Site.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of In November 1997, two 8,000-gallon and one 10,000-
<br /> any former and existing tank systems, excavation contours and gallon gasoline USTs were removed;and three 10,000-
<br /> sample locations, boring and monitoring well elevation gallon USTs were installed in the tank pit.
<br /> contours, gradients, and nearby surface waters, buildings,
<br /> streets, and subsurface utilities;
<br /> Y 3. Figures depicting lithology(cross section), treatment system Site litho/ogy consists of clay, silt,sand, and gravel to
<br /> diagrams; 65, the total depth investigated.
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Approximately 100 cubic yards of contaminated
<br /> excavated soil was transported to Forward Landfill in
<br /> Manteca.
<br /> R;Y 5. Monitorin wells remainin on-site, fate; Three monitoring wells(MW-1 through MW-3) will be properly abandoned.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 43'to 61'bgs. Groundwater flow
<br /> elevations and depths to water -- — -direction varied from northeast to southwest. Groundwater gradient
<br /> varied from 0.0003 to 0.013 Wt.
<br /> yJ 7. Tabulated results of all sampling All data adequately tabularized in various reports, including closure report
<br /> and analyses:
<br /> FYI Detection limits for confirmation
<br /> sampling
<br /> YI
<br /> Lead analyses
<br /> 8. Concentration contours of contaminants found and those remaining in soil and The extent of the identified
<br /> groundwater, and both on-site and off-site: contamination shown in applicable
<br /> reports.
<br /> Y❑Lateral and Y❑Vertical extent of soil contamination
<br /> FYI Lateral and Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used forsubsurface remediation An engineered remediation was not
<br /> system and the zone of capture attained for the soil and groundwater remediation required by the lead agency.
<br /> system;
<br /> YJ 10.Reports/information 0 Unauthonzed Release Form ❑Y QMRs 11 from 1/04 to 10/08
<br /> ❑Y Well and boring logs QY PAR ❑N FRP n Other Site Closure Report(8/08), Supplemental Closure
<br /> Re ort 11/09
<br /> Y I 11.Best Available Technology(BAT) used or an explanation for not USTs removal, over-excavation, and natural
<br /> using BAT,' I attenuation.
<br /> 12. Reasons why background was/is Minor residual soil contamination remains on-site.
<br /> Y
<br /> tfainable usin BAT;
<br /> Y 13.Mass balance calculation of substance treated The consultant estimates approximately 420 lbs TPH remains in soil..
<br /> versus that remaining;
<br /> Y 14. Assumptions, parameters, calculations and The soil results exceeded Region 2 ESLs. A J&E model cancer risk
<br /> model used in nsk assessments, and fate and was 7.07x10-6. Although the regulatory agency did not require a soil
<br /> transport modeling; gas survey, the majority of soil contamination is over 50'from the
<br /> building and located between 19'and 24'b s.
<br /> Y 15. Rationale why conditions remaining at site Soil contamination reportedly is limited in extent.Land use
<br /> will not adversely impact water quality, health, or (commercial)is not expected to change in the foreseeable future.
<br /> other beneficial uses;and
<br /> By: JLB Comments:In November 1997, two 8,000-gallon and one 10,000-gallon gasoline USTs were removed;and
<br /> Q." three 10,000-gallon USTs were installed in the tank pit at the subject site. Based upon 11 quarters of
<br /> Date: groundwater monitoring showing a stable plume with declining concentrations to non-detect, the limited
<br /> 12/2/2009 extent of contamination remaining in soil, no foreseeable changes in land use, and limited threats from soil
<br /> and soil vapor intrusion Regional Board staff concur with San Joaquin Count 's'Closure Recommendation.
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