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ABLE 1 - CHECKLIST OF REQUIRED DATk
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: FChapin Brothers Inc, 1766 Monte Diablo Avenue, Stockton, San Joaquin County(RB#390577)
<br /> Y 1. Distance to production wells for municipal, domestic, A 1994 sensitive receptor survey identified six public
<br /> agriculture, industry and other uses within 2000 feet of the site. supply well located within 2000'of the site. The nearest
<br /> wells(domestic well 250'to the north and an active
<br /> public supply 1,200'to west are not threatened.
<br /> Y1 2. Site maps, to scale, of area impacted showing locations of In August 1993, two 4,000-gallon gasoline,
<br /> any former and existing tank systems, excavation contours and two 8,000-gallon gasoline, and three 1,000-gallon
<br /> sample locations, boring and monitoring well elevation gasoline USTs, and one 550-gallon waste oil UST were
<br /> contours, gradients, and nearby surface waters, buildings, removed from the site.
<br /> streets, and subsurface utilities;
<br /> Y 3. Figures depicting lithology(cross section), treatment system Site lithology consists of clay, silt, sand and gravel to
<br /> diagrams; 40'bgs, the total depth investigated.
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Approximately 150 ycP of excavated soil was
<br /> transported to another Chapin Brothers Inc property,
<br /> and aerated until non-detect.
<br /> Y1 5. Monitoring wells remaining on-site, fate; Seven monitoring wells(MW-1 through MW-7), and twenty two remediation
<br /> wells(AS-1, VE-1 through VE-7, IAS-1 through IAS8, and EW-1 through EW6)
<br /> were properly abandoned on 10 December 2010.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 8'to 21'bgs. Groundwater flow
<br /> elevations and depths to water; direction varied from southeast to northwest. Groundwater gradient
<br /> varied from 0.0007 to 0.016 ft/ft.
<br /> LYJ 7. Tabulated results of all sampling All data adequately tabularized in various reports, including closure report.
<br /> and analyses:
<br /> FYIDetection limits for confirmation
<br /> sampling
<br /> ❑Y Lead analyses
<br /> LyJ 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 shown in applicable
<br /> reports.
<br /> ElLateral and ElVertical extent of soil contamination
<br /> RY Lateral and FYI Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface remediation Soil vapor extraction, air sparging, and
<br /> system and the zone of capture attained for the soil and groundwater remediation groundwater extraction were the
<br /> system; engineered remediation.
<br /> 10.Reports/information FY Unauthorized Release Form FYI QMRs 12/90 to 7/10
<br /> nY Well and boring logs ❑Y PAR FY FRP 0 Other Soil Vapor Report&HHRA (6/10),
<br /> Closure Report 8/10
<br /> Y 11.Best Available Technology(BAT) used or an explanation for not USTs removal, SVE/AS, groundwater extraction,and
<br /> using BAT,' I natural attenuation.
<br /> UI, 12. Reasons why background was/is Minor residual soil and groundwater contamination remains on-site.
<br /> ttainable using BAT-
<br /> 13.13.Mass balance calculation of substance treated The consultant estimates 957 lbs of TPHg removed from groundwater.
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<br /> versus that remaining; Approximately 5,733 lbs of TPHg remain in soil and 2.9 lbs remain in
<br /> groundwater.
<br /> Y 14. Assumptions, parameters, calculations and A soil vapor survey passed the Region 2 commercial vapor ESLs and
<br /> model used in risk assessments, and fate and CaIEPA CHHSLs.Residual TPHg in soil exceeded the gross
<br /> transport modeling; contamination and direct contact ESLs, but is located below 10'b s.
<br /> y, 1 15. Rationale why conditions remaining at site Soil and groundwater contamination reportedly is limited in extent.
<br /> will not adversely impact water quality, health, or Land use(commercial)is not expected to change in the foreseeable
<br /> other beneficial uses;and future. Vapor intrusion and soil risk has been addressed. Water quality
<br /> goals will be reached in 2035.
<br /> By: JLQy Comments: In August 1993, two 4,000-gallon gasoline, two 8,000-gallon gasoline and three 1,000-gallon
<br /> J�_1� gasoline USTs, and one 550-gallon waste oil UST were removed at the subject Site.Based upon 47 quarters
<br /> F5'
<br /> of groundwater monitoring showing a stable plume with declining concentrations, no threats to domestic
<br /> 11 and public supply wells, the limited extent of contamination remaining in soil and groundwater, no
<br /> foreseeable changes in land use, and limited threats from groundwater,soil and soil vapor intrusion,
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