SITE INFORMATION AND CORRESPONDENCE

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3.TABLE 1 -CHECKLIST OF REQUIRED DATA FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES Site Name and Location: Former Morita Brothers,814 E.Charter Way, Stockton, San Joaquin County(RB#390703) Y 1. Distance to production wells for municipal, domestic, A 2009 sensitive receptor survey stated no water supply agriculture, industry and other uses within 2000 feet of the site. wells were observed within 2000' of the site.The nearest public supply well was listed by DWR as 1350' southwest (crossgradient)of the site. Y 2. Site maps, to scale, of area impacted showing locations of Two 5,000-gallon and one 2,000-gallon gasoline,and one any former and existing tank systems, excavation contours and 500-gallon waste oil USTs were removed 12/91. sample locations, boring and monitoring well elevation contours, gradients, and nearby surface waters, buildings, streets, and subsurface utilities; Y 3. Figures depicting litho/ogy(cross section), treatment system Site lithology consists of clay,silt,and sand to 82',the diagrams; total depth investigated. Y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Approximately 760 cubic yards of soil excavated 5/93 during the UST over-excavation was transported to Forward Landfill in Manteca. :Y:1 5. Monitoring wells remaining on-site, fate; Nineteen monitoring wells(MW-1 through MW-7, MW-11, MW-104,MW-106 to MWA 11, MW-202, MW-208 through MW-210)will be properly abandoned. 6. Tabulated results of all groundwater Depth to groundwater varied from 30'to 54' bgs. Groundwater flow elevations and depths to water, direction varied from northeast to southeast.Groundwater gradient varied from 0.0012 to 0.018 fUft.. 7. Tabulated results of all sampling All data adequately tabularized in various reports, including closure report. and analyses: Detection limits for confirmation sampling QY Lead analyses 8. Concentration contours of contaminants found and those remaining in soil and The extent of the identified groundwater, and both on-site and off-site: contamination shown in applicable reports. Lateral and Y❑Vertical extent of soil contamination FY Lateral and Vertical extent of groundwater contamination NI 9. Zone of influence calculated and assumptions used for subsurface remediation An engineered remediation was not system and the zone of capture attained for the soil and groundwater remediation required by the lead agency. system; 10.Reports/information FY] Unauthorized Release Form ❑Y QMRs 56 from 10/92 to 11/08 ❑Y Welland boring logs EPAR ❑N FRP Other Soil and Soil Gas Investigation(4/08) Site Summary Closure Report 9/09 Y 1 11.Best-Available Technology-{BAT}used-or an explanation fornotusing _UST removal,over-excavation,_and.natural BAT, Iattenuation. Y 12. Reasons why background was/is unattainable Minor residual soil and groundwater contamination remains on-site. U BAT y 13.Mass balance calculation of substance treated The consultant estimates the remaining contaminant mass in versus that remaining; groundwater as 0.01 gallons of TPHg in 11/08. Y 14. Assumptions,parameters, calculations and The 2008 soil vapor sample results show Region 2 ESLs were not 7 model used in risk assessments, and fate and exceeded.The consultant estimated time for groundwater to reach transport modeling; WQGs as 5 to 8 years for TPH ,and 4 to 17 years for MTBE. Y 15. Rationale why conditions remaining at site will Soil and groundwater contamination reportedly are limited in extent. not adversely impact water quality, health, or other Land use(commercial) is not expected to change in the foreseeable benefcial uses;and future. By: Comments: Two 5,000-gallon and one 2,000-gallon gasoline, and one 500-gallon waste oil USTs were JL `-7 removed 12/91 from the subject site.Approximately 760 cubic yards of soil were over-excavated 5/93 and Date: transported offsite for disposal. Based upon 56 quarters of groundwater monitoring showing a stable plume 11/10/2009 with declining concentrations,the limited extent of contamination remaining in soil and groundwater, no foreseeable changes in land use and no soil vapor ESLs exceeded, Regional Board staff concur with San Joaquin County's Closure Recommendation.