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�— fABLE 1 -CHECKLIST OF REQUIRED DATPa o
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Former 3 B's Truck Plaza, 14749 N. Thornton Rd., Lodi, San Joaquin County(RB#390994)
<br /> Y71 Distance to production wells for municipal, A 2007(updated 2012)sensitive receptor survey reported 3 municipal
<br /> domestic, agriculture, industry and other uses and one industrial water supply wells within 2,000'of the Site. The
<br /> within 2000 feet of the site. nearest(municipal)wells are 1,100'to the north and 1,100'to the east.
<br /> The wells are not threatened by the release.
<br /> 2. Site maps, to scale, of area impacted showing locations of any former and In 10/98, one 12,000-gallon diesel and three
<br /> existing tank systems, excavation contours and sample locations, boring 12,000-gallon gasoline USTs were removed.
<br /> and monitoring well elevation contours, gradients, and nearby surface
<br /> waters, buildings, streets, and subsurface utilities;
<br /> Y 13. Figures depicting lithology(cross section), treatment Site lithology consists of clay,silt,sand, and gravel to 150', the
<br /> system diagrams; total depth investigated.
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal Approximately 250 ycP excavated soil was removed, tested, and
<br /> (quantity); reused as backfill in the excavation.
<br /> Y 5. Monitoring wells Seventeen (17)monitoring wells(MW-1 through MW-17)and twenty four(24)remediation wells
<br /> remainin on-site, fate; (VW-1 through VW-6, and AW-1 through AW-18)will be properly destroyed prior to closure.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 4'bgs to 19'bgs. Groundwater flow
<br /> elevations and depths to water, direction varied clockwise from southwest to southeast. Groundwater
<br /> gradient varied from 0.0008 to 0.005 ft/ft.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports.
<br /> and analyses:
<br /> ElDetection limits for confirmation
<br /> sampling
<br /> EN 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 /> it Lateral and ElVertical extent of soil contamination
<br /> FYI Lateral and Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface Soil vapor extraction (SVE) with air sparging
<br /> remediation system and the zone of capture attained for the soil and (AS)was the engineered remediation.
<br /> groundwater remediation system;
<br /> 10.Reports/information [Y Unauthorized Release Form [R] QMRs(46)4-99 to 6-12
<br /> RY Well and boring logs 10 PAR 10 FRP nY Other. Closure Report, 10/12; WQOs Supplement, 2-13
<br /> Y 11.Best Available Technology(BAT) used or an explanation USTs removal, SVE/AS,and natural attenuation.
<br /> for not using BAT
<br /> Ir 12. Reasons why background wasrs Residual soil and groundwater contamination remains.
<br /> ttainable using BAT,,
<br /> Y 13.Mass balance calculation of substance SVE removed approximately 74,000 lbs TPH from soil. 10,525 lbs TPH
<br /> treated versus that remaining; remain in soil. Consultant did not estimate mass in groundwater.
<br /> 7Y 14. Assumptions, parameters, calculations A soil vapor survey passed the Region 2 ESLs. Soil met SWRCB low risk
<br /> and model used in risk assessments, and fate closure policy for commercial use. Consultant states site does not
<br /> and transport modeling, represent a significant risk.
<br /> Y 15. 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.
<br /> or other beneficial uses;and Consultant estimated WQGs will be reached by 2019. Groundwater plume
<br /> is stable and declining.
<br /> By: JL Comments:In 10/98, one 12,000-gallon diesel and three 12,000-gallon gasoline USTs were removed at the
<br /> subject site. Residual soil and groundwater contamination remains. Based upon the limited extent of
<br /> Date: contamination reported in soil and groundwater, a stable and declining concentration plume, no foreseeable
<br /> 3/26/2013 changes in future land use(commercial), and minimal risks from groundwater,soil vapor and soil, Regional
<br /> Board staff concur with San Joaquin County's Closure Recommendation.
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