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<br /> - �rr�ABLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Raymond investment Corp., 730 E. Channel St., Stockton, San Joaquin County(RB 9399951)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2006 sensitive receptor survey reported six water supply
<br /> agriculture, industry and other uses within 2044 feet of the wells(nearest well is 9;969'north-northeast)within ase.
<br /> of the Site. The wells are not threatened by this.release.
<br /> site.
<br /> Y::] 2. Site maps, to scale, of area impacted showing locations of any former In 4103, one 9,000-gallon unknown use UST was
<br /> and existing tank systems, excavation contours and sample locations, removed.
<br /> boring and monitoring well elevation contours, gradients, and nearby
<br /> surface waters, buildings, streets, and subsurface utilities;
<br /> Site lithology consists of clay,silt,and sand to
<br /> Y 3. Figures depicting lithology(cross section), treatment system diagrams; 72, 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 /> 7y 5. Monitoring wells remaining on-site, fate; Fight(8)monitoring wells(MW-1, MW-2, MW-3R, MW-4,MW-4D, and MW-5
<br /> through MW-7)and three(3)soil vapor wells(SV-4 through SV-6)will be
<br /> properlydestroyed.
<br /> 6. Tabulated results of al!groundwater Depth to groundwater varied from 28'bgs to 37'bgs. Groundwater flow direction
<br /> elevations and depths to water; was towards the east-northeast. The a groundwater gradient varied from 0.0038
<br /> to 0.007 ft*.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports,including closure report. 'and analyses:
<br /> 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 /> 0 Lateral and 0 Vertical extent of soil contamination
<br /> FYI Lateral and M 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 1 information F7 Unauthorized Release Form 0 QMRs (25) 11-04 to 8-11
<br /> 171 Well and boring logs PAR FRP Other Closure Report(4-12)
<br /> Y11.Best Available Technology (BAT) used or an explanation USTs removal and natural attenuation.
<br /> for not using BAT; i
<br /> Y 12. Reasons wiry background walls unattainable, Residual soil and groundwater contamination remains.
<br /> BAT;
<br /> y 13.Mass balance calculation of substancetreated Consultant estimated approximately 364.95 gal. of TPH remains in
<br /> versus that iemainirt ,` - —` soil ond-0.-7gal:-of-T-PH-remains4n-groundwater;�
<br /> Y 14. Assumptions, parameters, calculations and Soil vapor passed a J&E Model. Soil failed the ESLs for gross J
<br /> model used in risk assessments, and fate and contamination and direct contact for TPHg.(6'bgs), TPHd(20'bgs),
<br /> transport modeling; ethylbenzene(20'bgs),and xylenes(6'bgs). Consultant states site
<br /> does not re resent a si niticant risk.
<br /> 15. Rationale wiry conditions remaining at site will Soil contamination reportedly is limited in extent. Groundwater
<br /> not adversely impact water quality, health, or other plume is stable and declining. Land use(public street)is not
<br /> beneficial uses;and expected to change in the foreseeable future. TPH will reach WQGs
<br /> in 2050.
<br /> By: JL46Comments:In 4103, one 1,000-gallon unknown use UST was removed at the subject site.Residual soil and
<br /> groundwater contamination remains.Based upon the limited extent of contamination reported in soil and
<br /> Date: groundwater, groundwater reaching WQGs by 2050,no foreseeable changes in future land use(commercial),
<br /> 10/8/2012 and minimal risks from soil vapor, soil,and groundwater,Regional Board staff concur with San Joaquin
<br /> County's Closure Recommendation.
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