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"--rABLE 1 -CHECKLIST OF REQUIRED DATA,
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Former Cheaper Store#37, 15 E. Grantline Rd, Tracy, San Joaquin County(RB#390171)
<br /> y 1 1. Distance to production wells for municipal, domestic, A 2008 sensitive receptor survey reported two water supply
<br /> agriculture, industry and other uses within 2000 feet of the wells(500'northwest and 1,000'west)within 2,000'of the
<br /> site. Site. The wells are not threatened by this release.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of any former In 3-98, two 10,000-gallon gasoline USTs were
<br /> and existing tank systems, excavation contours and sample locations, removed. In 9-03, one 520-gallon waste oil UST
<br /> boring and monitoring well elevation contours, gradients, and nearby was removed.
<br /> surface waters, buildings, streets, and subsurface utilities;
<br /> Y 3. Figures depicting lithology(cross section), treatment system diagrams; Site lithology consists of clay,silt,and sand to
<br /> 80', the total depth investigated.
<br /> Y 4. Stockpiled soil remaining on
<br /> or off-site disposal Approximately 66 yds. of excavated soil was transported to
<br /> uantit Forward Landfill in Manteca.
<br /> Y 5. Monitoring wells remaining on-site, Eight(8)monitoring wells(MW-1 through MW-8)will be properly destroyed.
<br /> a e;
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 4'bgs to 11'bgs. Groundwater flow direction
<br /> elevations and depths to water, varied clockwise from south to northeast. Groundwater gradient varied from
<br /> 0.0017 ft/ft to 0.0064 ft/ft.
<br /> 7.-Tabulated-results-of all sampling All data adequately tabularized in various reports,including closure report.
<br /> and analyses:
<br /> aDetection limits for confirmation
<br /> sampling
<br /> �Y Lead analyses
<br /> LyJ 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 /> Vertical extent of soil contamination
<br /> El Lateral and
<br /> MY Lateral and M Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface Over-excavation and free product removal
<br /> remediation system and the zone of capture attained for the soil and (FPR) were the engineered remediation.
<br /> groundwater remediation system;
<br /> 10.Reports/information IS Unauthorized Release Form QY QMRs(52)3-88 to 3-11
<br /> ❑Y Well and boring logs nY PAR � FRP 0 Other Closure Report(11-11)
<br /> YJ 11.Best Available Technology(BAT) used or an explanation USTs removal, over-excavation, FPR, and natural
<br /> for not using BAT; I attenuation.
<br /> Y 12. Reasons why background was/is unattainable Residual soil and groundwater contamination remains.
<br /> BAT,
<br /> Consultant estimated 638 lbs. of TPH remain in soil and 0.02 tbs. of
<br /> Y 13.Mass balance calculation of substance treated
<br /> _ _TPH remain in groundwater.
<br /> versus that remaining,
<br /> Y 14. Assumptions, parameters, calculations and A soil vapor survey passed a Tier 2 evaluation for TPHg. Soil failed
<br /> model used in risk assessments, and fate and Region 2 ESLs for direct exposure(DE)and gross contamination
<br /> transport modeling; for TPHg and DE for benzene at 6'bgs, which is near or below the
<br /> water table 'b s in 2011 . Water quality goals have been reached.
<br /> 7Y 15. Rationale why conditions remaining at site will Soil and groundwater contamination reportedly are limited in
<br /> not adversely impact water quality, health, or other extent.Land use(commercial)is not expected to change in the
<br /> beneficial uses;and foreseeable future. WQGs have been reached.
<br /> By: JLBJ Comments:In 3-98, two 10,000-gallon gasoline USTs were removed at the subject site. In 9-03, one
<br /> 520-gallon waste oil UST was removed at the subject site. Residual soil and groundwater contamination
<br /> Date: remains.Based upon the limited extent of contamination reported in soil and groundwater, groundwater that
<br /> 12/10/2012 has reached WQGs, no foreseeable changes in future land use(commercial), and minimal risks from
<br /> groundwater,soil vapor and soil, Regional Board staff concur with San Joaquin County's Closure
<br /> Recommendation.
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