SITE INFORMATION AND CORRESPONDENCE

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r•a'�.""" may' -� ^'- r �1_E 1 -CHECKLIST OF REQUIRED DATA FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES Site Name and Location: Sarale Farms, 16500 W. Clifton Court Rd.,Stockton, San Joaquin County(RB#390767) y 1. Distance to production wells for municipal, A 2012 sensitive receptor survey reported one domestic supply domestic, agriculture, industry and other uses well(300'north)located within 2,000'of the Site. The well tested within 2000 feet of the site. ND for TPH in 2012 and is not threatened by the release. y 2.Site maps,to scale, of area impacted showing locations of any In 12/92, one 10,000-gallon gasoline UST was former and existing tank systems, excavation contours and removed. Site maps and figures showing tank sample locations, boring and monitoring well elevation locations, excavations,building and residual contours,gradients, and nearby surface waters,buildings, pollutants were provided in investigation reports. streets,and subsurface utilities; Y 3.Figures depicting lithology(cross Site lithology consists of clay,silt,and sand to 100', the total depth investigated. section, treatment system diagrams; No treatment system was constructed. N 4. Stockpiled soil remaining on-site The fate of the approximately 20 y of over-excavated soil was not discussed in or off-site disposal(quantity); the available reports. The consultant did not estimate mass removed from soil. Tat 5.Monitoring wells remaining on-site, Eleven(11)monitoring wells(MW--1 through MW-11) will be properly destroyed e; I prior to closure. 6. Tabulated results of all groundwater Depth to groundwater varied from 1'bgs to 7'bgs. Groundwater flow direction elevationsanddepths to water, - varied-clockwise.fr._om_southwest_to_northeast.,Groundwater-gradient-varied—.— from 0.0003 ft/ft to 0.007 ft/ft. 7. Tabulated results of all sampling All data adequately tabularized in various reports. and analyses: Y❑ Detection limits for confirmation sampling 5Lead analyses 8. Concentration contours of contaminants found and those remaining in The horizontal and vertical extent of the soil and groundwater,and both on-site and off-site: petroleum contamination is confined to the property limits. 0 Latera!and 0 Vertical extent of soil contamination Latera!and FiVertical extent of groundwater contamination 9.Zone of influence calculated and assumptions used for subsurface An engineered remediation was not remediation system and the zone of capture attained for the soil and required by the regulatory agency. groundwater remediation system; 10.Reports/information rY] Unauthorized Release Form 0 QMRs(31)6-03to 9-11 PAR 0 FRP 1 Other No Further Action Report, 7-12 Soil Vapor 0 Well and boring logsFY] lnvesti scion, 5-13 Y- .11.Best Available Technology(BAT)used or an Leak was stopped by removing tank and piping,use of explanation for not using BAT; additional cleanup technology was not needed to be protective of human health and the environment. a f 2: Reasons-why-background-v✓as/is not- --Soil-contamination-does notpresent a-threatTo human health and - -- — MYand inable usin BAT; roundwater ollution is redicted to be restored in 55 ears. 13.Mass balance calculation of substance Consultant estimated residual TPH mass as 256 lbs. in soil and treated versus that remainin ; 12.5 lbs. in groundwater. 14. Assumptions,parameters, calculations Site passed LTCP and Region 2 ESLs above 4'bgs(benzene,4.3 mg/kg model used in risk assessments,and fate failed ESL direct contact at 4'bgs). State Board recommended the case and transport modeling; for closure. Consultant states site does not represent a significant environmental or health risk. 15. Rationale why conditions remaining at Soil and groundwater contamination reportedly are onsite. Land use site will not adversely impact water quality, (commercial)is not expected to change in the foreseeable future. WQGs health, or other beneficial uses;and will be reached by 2068. Groundwater plume is stable and very slowly decreasing in concentration. By: JLB Comments:In 12/92, one 10,000-gallon gasoline UST was removed at the subject site.Based on the stable and declining concentrations in groundwater, no foreseeable changes in future land use(commercial),and Date: no risks from-soil vapor and soil, Regional Board staff concur with San Joaquin County's Closure 7/30/2013 'Recommendation.