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SABLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUNeANK SITES
<br /> Site Name and Location: Low Price Auto Glass/Former Texaco/Chevron#309075.,Stockton, San Joaquin County
<br /> (RB#391128)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2012 sensitive receptor survey reported 17 water supply
<br /> agriculture, industry and other uses within 2000 feet of the wells(nearest is domestic 80'northeast)within 2,000'of
<br /> the Site. The wells are not threatened by this release.
<br /> site.
<br /> _YJ2. Site maps, to scale, of area impacted showing locations of any former In 1973(exact date unknown), one 550-gallon,one
<br /> and existing tank systems, excavation contours and sample locations, 3,987-gallon, one 4,000-gallon,and one 6,300-
<br /> boring and monitoring well elevation contours, gradients, and nearby gallon unknown contents USTs were reported
<br /> surface waters, buildings, streets, and subsurface utilities; removed by the regulatory agency(A geophysical
<br /> survey did not find evidence of USTs).
<br /> Y 3. Figures depicting lithology(cross section), treatment system diagrams; Site lithology consists of clay,silt,and sand to
<br /> 150', the total depth investigated.
<br /> N 4. Stockpiled soil remaining on-site or off-site disposal The fate of excavated soil was not discussed in the available
<br /> (quantity); reports.
<br /> Y 5. Monitoring wells remaining on-site, fate; ISeven(7)monitoring wells(MW--1 through MW-6,and MW-6D)will be
<br /> properly destroyed.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 50'bgs to 67'bgs. Groundwater flow direction
<br /> elevations and depths to water, I varied from southwest counterclockwise to northeast at a gradient of 0.001 fttft
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports,including closure report.
<br /> and analyses:
<br /> 0 Detection limits for confirmation
<br /> sampling
<br /> ❑N 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 /> FX]Lateral and Y❑Vertical extent of soil contamination
<br /> Lateral and Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface An engineered remediation was not required
<br /> remediation system and the zone of capture attained for the soil and by the regulatory agency.
<br /> groundwater remediation system;
<br /> 10.Reports/information ❑Y Unauthorized Release Form QY QMRs(52) 8-96 to 6-11
<br /> FY-1 well and boring logs ❑y PAR ❑N FRP �y Other Closure Report(7-12)
<br /> YJ 11.Best Available Technology(BAT) used or an explanation USTs removal and natural attenuation.
<br /> for not using BAT;
<br /> 12. Reasons why background wasrs unattainable Residual soil and groundwater contamination remains on-site.
<br /> Y
<br /> BAT-
<br /> Y 13.Mass balance calculation of substance treated Consultant estimated approximately 519 lbs TPH remain in soil and
<br /> versus that remaining; -- 0.69 lbs TPH remain in groundwater.
<br /> 7Y 14. Assumptions,parameters, calculations and Soil vapor was not tested. In 2002 TPHg exceeded ESLs at 15'bgs.
<br /> model used in risk assessments, and fate and 2008 confirmation borings did not detect soil contamination.
<br /> transport modeling; Nearby domestic well was sampled three times with no petroleum
<br /> hydrocarbons detected. Consultant states site does not represent
<br /> a significant risk.
<br /> Y 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. Groundwater plume is slightly increasing(TPHmo),stable
<br /> beneficial uses;and (TPHd)or decreasing(TPHg, 1, 2-DCA) with BTEX ND or below
<br /> MCLs.Land use(commercial)is not expected to change in the
<br /> foreseeable future. 1, 2-DCA in groundwater is estimated to reach
<br /> MCLs in 2017, TPHd/mo in 75 years.
<br /> By: JL_ Comments:In 1973(exact date unknown), one 550-gallon, one 3,987-gallon, one 4,000-gallon,and one 6,300-
<br /> gal/on unknown contents USTs were reported by the regulatory agency as removed at the subject site.
<br /> Date: Residual soil and groundwater contamination remains on-site. Based upon the limited extent of
<br /> 9/11/2012 contamination reported in soil and groundwater,a stable groundwater plume, no foreseeable changes in
<br /> future land use(commercial), and minimal risks from soil vapor,soil and groundwater, Regional Board staff
<br /> concur with San Joaquin Countys Closure Recommendation.
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