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ULE 1 -CHECKLIST OF REQUIREDI DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Quik Stop Markets No. 132, 3555 W. Hammer Ln, Stockton, San Joaquin County(RB#390533)
<br /> Y 1. Distance to production wells for municipal, domestic, agriculture, A 2011 sensitive receptor survey reported no water
<br /> industry and other uses within 2000 feet of the site. supply wells within 2,000'of the site. Ip
<br /> Y 2. Site maps, to scale, of area impacted showing locations of any In 6-90, one 8,000-gallon gasoline and two 10,000-
<br /> former and existing tank systems, excavation contours and sample gallon gasoline USTs and associated piping and
<br /> locations, boring and monitoring well elevation contours, gradients, dispensers were removed.An investigation showed
<br /> and nearby surface waters, buildings, streets, and subsurface the piping was the source of the TPH release.
<br /> utilities;
<br /> Y1 3. Figures depicting lithology(cross section), treatment system Site litho/ogy consists of clay,silt,and sand to 32,
<br /> diagrams; the total depth investigated. -
<br /> Y 4. Stockpiled soil remaining:on-site or off-site disposal Approximately 500 y excavated soil was transported to BFI
<br /> (quantity); Landfill in 1990, and 90 yd"excavated soil was transported to
<br /> Forward Landfill in Manteca in 1991.
<br /> Y 5. Monitoring wells remaining on-site, fate; Nine(9)remaining monitoring wells(MW-1R, MW-2 through MW-8,and
<br /> MW-11) will be property destroyed.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from Whigs to 18'bgs. Groundwater flow
<br /> I direction was towards the southeast. Groundwater gradient varied from
<br /> r elevations and depths to water,
<br /> t: 0.002 ft/ft to 0.003 ft/h.
<br /> 7.-Tabulabed results of a�ihli - 'A7I da'ta'adeaelk tabuTarized-m varfou's reporfs;i��ing'closure repo ti:
<br /> and analyses:
<br /> Y❑ Detection limits for confirmation
<br /> i
<br /> sampling
<br /> 0 Lead analyses - -
<br /> 8. Concentration contours of contaminants found and those remaining in soil and The extent of the identified
<br /> groundwater,and both on-site and off-site: contamination is described in the
<br /> available reports.
<br /> Y❑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 remediation An engineered remediation was not
<br /> system and the zone of capture attained for the soil and groundwater remediation required by the regulatory agency.
<br /> system;
<br /> 10.Reports/information Unauthorized Release Form 0 QMRs (75) 8-90 to 9-10
<br /> FY] Well and boring logs - PAR 0 FRP FY] Other Site Conceptual Model(11-06), Closure Report
<br /> .i
<br /> ..i -`--
<br /> Y 1 L Best Available Technology(BAT)used or an explanation for not using i UST removal, over-excavation,and natural
<br /> BAT; I attenuation. 11
<br /> :ag12 Reasons why background wasrs unattainable Residual soil and groundwater contamination remains on-site.
<br /> BAT, Initial soil mass estimated as 15 lbs of TPH. Initial groundwater mass
<br /> V3.-Mass-balanee,calculatio
<br /> n-of-substancelreated— -tvas"0:55"lbs o 7PHt
<br /> r'Consu ant eshmataa pro -0
<br /> p xrma—[e7y0311bs
<br /> versus that remaining; - -
<br /> of TPH remain in groundwater in 2006. r
<br /> Y 14. Assumptions, parameters, calculations and A 1992 soil vapor survey passed the Region 2 ESLs for commercial
<br /> model used in risk assessments, and fate and use. Soil results failed ESLs for gross contamination and direct
<br /> transport modeling; contact(TPHg)and direct exposure(benzene, toluene, ethylbenzene,
<br /> and xylenes)at 2'bgs, below the piping trench in 8-90. Consultant
<br /> states site does not represent a significant risk.
<br /> Y 15. Rationale why conditions remaining at site will Soil and groundwater contamination reportedly are limited in extent
<br /> not adversely impact water'iquality, health, or other Land use(commercial)is not expected to change in the foreseeable
<br /> beneficial as;and I future. Groundwater has reached WQGs.
<br /> By: J Comments:In 6-90, one 8,000-gallon gasoline and two 10,000-gallon gasoline USTs and associated piping
<br /> and dispensers were removed at the subject site. An investigation showed the piping was the source of the
<br /> Date: TPH release. Minor residual soil and groundwater contamination remains on-site.Based upon the limited
<br /> 2/8/2012 extent of contamination reported in soil and groundwater,a stable groundwater plume with declining
<br /> concentrations that have reached WQGs, no foreseeable changes in future land use(commercial), and
<br /> minimal risks from soil,soil vapor,and groundwater, Regional Board staff concur with San Joaquin
<br /> County's Closure Recommendation.
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