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!ABLE 1 -CHECKLIST OF REQUIRED DATL"
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Speedy Foods, 8200 N. Hwy.99, Stockton, San Joaquin County(RB#390911)
<br /> y 1. Distance to production wells for municipal,domestic, Site supply well located 120'east of the groundwater
<br /> agriculture, industry and other uses within 2000 feet of the site. plume, and 3 domestic wells located downgradlent and
<br /> adjacent to Site(320'and 400'to NE and 525'to NW)
<br /> have not been impacted.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of any In January 1998, three 8,000-gallon gasoline USTs were j
<br /> former and existing tank systems, excavation contours and removed.
<br /> sample locations, boring and monitoring well elevation contours,
<br /> gradients, and nearby surface waters, buildings, streets, and
<br /> subsurface utilities,
<br /> Y 3. Figures depicting lithology(cross section), treatment system Site lithology consists of clay, silt, and sand to 300'. the
<br /> diagrams; total depth investigated.
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Approximately 166 yards of over-excavated soil was
<br /> transported to Forward Landfill in Manteca.
<br /> Y 5. Monitoring wells remaining on-site, fate; Eight monitoring wells(MW-3, MW-4, MW-6, MW-12, MW-15, MW-16, MW-9B1
<br /> and MW-13C), two vapor wells(VW-1 and VW-2), and two groundwater
<br /> extraction wells MW-1/EW-1 and EW-3 will be proper!y proper! abandoned.
<br /> 6-Tabulated results of a#groundwater. _h epth to groundwater varied from 56'to 76'bgs. Groundwater flow
<br /> elevations and depths to wafer,
<br /> 1�irection varied-from north-northeast to east=Groundwater gradient
<br /> varied from 0.001 to 0.01 ft/ft.
<br /> 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 /> EY 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 /> ElLateral and 0 Vertical extent of soil contamination
<br /> FYI Lateral and Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface remediation Over-excavation, soil vapor and dual
<br /> system and the zone of capture attained for the soil and groundwater remediation phase extraction,groundwater pump
<br /> system; and treatment, and natural attenuation.
<br /> 10.Reports/information QY Unauthorized Release Form FY QMRs 42 from 10199 to 2110
<br /> PAR FRP Fy Other 2 closure reports(7-10, 8-10)
<br /> �Y Well and boring logs j
<br /> Y 11.Best Available Technology(BAT) used'or an explanation for not USTs'removal, over-excavation, air sparging, dual
<br /> using BAT; phase extraction, groundwater pump and treatment,
<br /> and natural attenuation.
<br /> Y 12. Reasons why background waslis Minor residual soil and groundwater contamination remains on-site. --
<br /> - - - ttainable-using-.BA T
<br /> y 13.Mass balance calculation of substance treated SVE(DPE removed 2,500 ibs'of TPH from soil.Hand bailing removed
<br /> 1,200 lbs and pump& treat removed 183 lbs of TPH from groundwater.
<br /> versus that remaining, 9.6 lbs of TPH remain in'groundwater; 156 lbs. of TPH remain in soil.
<br /> 14. Assumptions,parameters, calculations and The regulatory agency did not require a soil vapor survey, due to the
<br /> :Y:1 model used in risk assessments, and fate and location of residual soil contaminants(65), depth to groundwater(76)
<br /> transport modeling; limiting threats from unsaturated zone vapor intrusion, and no change
<br /> in site use convenience store).
<br /> Y 15. Rationale why conditions remaining at site Soil and groundwater contamination reportedly is limited in extent.
<br /> will not adversely impact water quality, health, or Land use(commercial)is not expected to change in the foreseeable
<br /> other beneficial uses;and future. Vapor intrusion risk has been addressed. The water supply
<br /> wells have never been impacted. Water quality goals will be reached in
<br /> approximatelz 30 years.
<br /> .By. JLB� Comments:In January 1998, three 8,000-gallon gasoline USTs were removed from the subject Site.Based
<br /> upon 42 quarters of groundwater monitoring showing a stable plume with declining concentrations, the
<br /> Date; limited extent of contamination remaining in soil and groundwater, no foreseeable changes in land use, and
<br /> 9/7/2010 limited threats from groundwater, soil and soil vapor intrusion, Regional Board staff concur with
<br /> San Joa uin County's Closure
<br /> Recommendation.
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