SITE INFORMATION AND CORRESPONDENCE FILE 2

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BLE 1 -CHECKLIST OF REQUIRED DATA `*+! FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES Site Name and Location: Steve&Gene's Service,2315 North E/Dorado Street,Stockton,CA 95204 N 1. Distance to production wells for municipal, domestic, Five water supply wells were identified within 2,000'of the Site. agriculture, industry and other uses within 2000 feet of the site; The closest well is located 1,101 ft.west and up-gradient from the Site.None of the wells are at risk from impacts from the Site. Y 2. Site maps, to scale, of area impacted showing locations of former In 4/87,two 3,000-gallon gasoline USTs and one 200- and existing tank systems, excavation contours and sample locations, gallon waste oil UST along with all associated piping and dispensers were removed from the subject site.Site borings and monitoring wells elevation contours, gradients, and nearby maps and figures showing tank locations,area of surface waters, buildings, streets, and subsurface utilities; excavations,buildings,and residual pollutants are provided in investigation reports. 1' 3. Figures depicting lithology(cross Cross section figures are provided in site characterization reports.Site litho/ogy section), treatment system diagrams; consists of inter-bedded silts,clay and sands to a total investigated depth of 150 feet. Y 4. Stockpiled soil remaining on-site or No soil was stockpiled at this Site. off-site disposal(quantity); 5E . Monitoring wells remaining on-site, fate; All remaining monitoring wells will be properly destroyed following concurrence to Y closure. Y 6. Tabulated results of all groundwater Depth to groundwater has varied from 40'bgs to 25'bgs.Groundwater flow direction is elevations and depths to water, to the east-northeast 7.Tabulated results of all sampling and analyses: All data adequately tabularized in various reports. Waste oil tank analytes evaluated using groundwater samples. Y FY I Detection limits for confirmation sampling 0 Lead analyses Y 8. Concentration contours of contaminants found and those remaining in soil Petroleum hydrocarbon impacts extend to 80'bgs and groundwater, and both on-site and off-site: and to a horizontal length of approximately 215'. NYLateral and Y Vertical extent of soil contamination Lateral and LYJ Vertical extent of groundwater contamination N 9. Zone of influence calculated and assumptions used for subsurface Vapor extraction wells were designed and remediation system and the zone of capture attained for the soil and constructed to capture approx. 15 feet of radial groundwater remediation system; influence. Y 10.Reports/information ❑Y Unauthorized Release Form ❑Y QMRs MY Well and boring logs HN PAR EY FRP 0Y Other Y 11.Best Available Technology(BAT) used or an Soil vapor extraction and air sparging technologies were implemented as BAT. explanation for not using BAT; Y 12.Reasons why background wasrs unattainable Rising groundwater levels caused groundwater to enter and saturate the SVE and using BAT,' AS systems in 2012 at which time LTCP standards had been achieved in the soil g and groundwater,therefore no further remediation was implemented. Y 13.Mass balance calculation of substance Approx.877gallons of TPH-G was removed by the SVE system.Consultant did not treated versus that remaining; calculate remaining mass of constituents of concern. Y 14. ,Assum tionsparameters, calculations and model used The remaining soil,soil vapor and groundwater concentrations meet Assumptions,p LTCP criteria and can therefore be assumed that residual pollutants do in risk assessments, and fate and transport modeling; not pose a significant risk to human health or environmental 15.Rationale why conditions remaining at site will not Site is expected to reach background conditions by 2036. The impacted groundwater shows a stable and decreasing trend and does not pose a Y adversely impact water quality, health, or other beneficial threat to human health or the environment according to Advanced uses;and GeoEnvironmental Inc. N 16.WET or TCLP results n/a Comments: The Site is currently in use as an automobile maintenance facility and there are no plans in the foreseeable future for the land use to change.In 1987,the UST system was removed and soil samples verified that a release had By:CLC occurred from the dispenser island.Remediation has been conducted at the Site,removing approx.887 gallons of TPH-G through SVE. The Site is projected to meet background conditions by 2036. The case meets the criteria of the State Water Board's Low Threat Closure Policy and therefore should not pose a threat to human health or the environment. Tetrach/oroethene(PCE)and trichloroethane(TCE)detected in in the area groundwater including up-gradient well MW-9 Date:7/24/2014 from an unknown source.