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TLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Marci Property(Marci's Diesel Service),2969 Loomis Rd.,Stockton,San Joaquin County
<br /> (RB#390083)
<br /> Y 1. Distance to production wells for municipal, A 2011 sensitive receptor survey reported 1 municipal and 12 domestic
<br /> domestic, agriculture, industry and other uses water supply wells within 2,000'of the Site. The nearest wells are the
<br /> within 2000 feet of the site. municipal well located 200'east and a domestic well 450'south.None
<br /> of the wells are threatened by the release.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of any former In 3187, two 5,000-gallon diesel USTs were
<br /> and existing tank systems, excavation contours and sample locations, removed.Soil was excavated-to 29'bgs and
<br /> boring and monitoring well elevation contours, gradients, and nearby backfilled with clean soil.
<br /> surface waters, buildings, streets, and subsurface utilities;
<br /> Y 3. Figures depicting lithology(cross section), treatment Site lithology consists of clay,silt,sand, and gravel to 85', the
<br /> system diagrams; total depth investigated.
<br /> N 4. Stockpiled soil remaining on-site or off-site disposal The fate of the excavated soil is not discussed in the available
<br /> (quantity);
<br /> reports.
<br /> Y 5. Monitoring wells All monitoring wells(MW--1 through MW-8,MW-104 through MW-106)and remediation wells(AS-1,
<br /> remainin on-site, fate; EW-1 through EW-7,EW-101, EW-102,IW-1,and IW-101)will be properly destroyed prior to closure.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 46'bgs to 68'bgs. Groundwater flow
<br /> elevations and depths to water, direction varied from northeast to-southeast. Groundwater gradient varied
<br /> from 0.0001 to 0.017 ft(ft.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports.
<br /> and analyses:
<br /> FYI Detection limits for confirmation
<br /> sampling
<br /> �Y Lead analyses
<br /> 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 /> Y❑Lateral and El Vertical extent of soil contamination
<br /> MY Lateral and F1 Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface Biosparging(BSG),bioventing(BVG),and
<br /> remediation system and the zone of capture attained for the soil and dual phase extraction(DPE)were the
<br /> groundwater remediation system; enctineered remediation.
<br /> 10.Reports/information QY Unauthorized Release Form ❑Y QMRs(40)8-00 to 6-11
<br /> QY Welland boring logs ❑Y PAR 0 FRP ❑Y Other Closure Report,4-12
<br /> Y11.Best Available Technology(BAT) used or an explanation USTs removal, over-excavation, BSG,BVG,DPE,and
<br /> for not using BAT; I natural attenuation.
<br /> UY 12. Reasons why background wasfis Residual soil and groundwater contamination remains.
<br /> ttainable using BAT;
<br /> 7113.Mass balance calculation of substance Consultant estimated initial mass as 17,356 gal. of TPHd in soil.
<br /> treated versus that remaining; Approximately 3,314 gal remain in soil and 4 gal,remain in groundwater.
<br /> Y 14. Assumptions,parameters, calculations A soil vapor survey was not required by the regulatory agency.Soil
<br /> 7
<br /> and model used in risk assessments, and fate borings show TPHd exceeds Region 2 ESLs below 10'bgs, which is
<br /> and transport modeling; below typical worker exposure depths. TPHd groundwater plume has
<br /> remained onsite. All water supply wells within 600'were ND in 2011.
<br /> Consultant states site does not represent a significant risk. Site meets
<br /> SWRCB low risk closure policy.
<br /> Y 115. Rationale why conditions remaining at site Soil and groundwater contamination reportedly are limited in extent.Land
<br /> will not adversely impact water quality, health, use(commercial)is not expected to change in the foreseeable future.A
<br /> or other beneficial uses;and fate and transport model shows that sensitive receptors are protected.
<br /> Based on data natural log trend analysis, WQGs will be reached by 2014.
<br /> By: JL Comments:In 3/87, two 5,000-gallon diesel USTs were removed at the subject site.Residual soil and
<br /> groundwater contamination remains.Based upon the limited extent of contamination reported in soil and
<br /> r22 ; 013
<br /> groundwater,a stable plume that has remained onsite,no foreseeable changes in future land use
<br /> (commercial),and minimal risks from groundwater,soil vapor and soil,Regional Board staff concur with
<br /> San Joaquin County's Closure Recommendation.
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