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` t` ,SLE 1 -CHECKLIST OF REQUIRED VATA� ;�
<br /> FOR NO FUR7WR ACTION REQUESTS AT t,1NDERGROUN6%JNK SITES
<br /> Site Name and Location: Ruth Strong Property, 5157 W. 205 Business Loup, Tracy; San Joaquin County(RB#390414)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2005 sensitive''receptor survey found 3 water supply
<br /> f agriculture, industry and other uses within 2000 feet of the site. wells, one 230'west;one 250 north, and one 200
<br /> northeast of thelSite;none have been impacted.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of In August 1989, two 1,500-gallon gasoline, one
<br /> any former and existing tank systems, excavation contours and 6,500-gallon and one 10,000 diesel;and one 1,500-gallon
<br /> sample locations, boring and monitoring well elevation waste oil USTs were removed.
<br /> contours, gradients, and nearby surface waters, buildings,
<br /> streets, and subsurface utilities;
<br /> f Y 3. Figures depicting lithology(cross section), treatment system Site lithology consists of clay,sift,and sand to 110, the
<br /> total depth investigated.
<br /> diagrams;
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Approximately',639 tons of over-excavated soil was
<br /> transported to;Forward Landfill in Manteca.
<br /> 5. Monitoring wells remaining on-site, fate;
<br /> Thirteen monitoring wells(MW-1A,MW-2A, MW-3 through
<br /> 'Y t
<br /> MW-12 ro will be erl abandoned:
<br /> Depth'to groundwater varied from 8'to 15'bgs. Groundwater flow
<br /> 6. Tabulated results of all groundwater .n
<br /> elevations and depths to water, direction varied fromortheastjto northwest. Groundwater gradient
<br /> varied from 0.0009 to 0-t11 ft/ft. Ii
<br /> 7. Tabulated 4ults of all Tamp-lin`g -Alldata-adequately tabularized"fn-various'reports;including-closure-report.and analyses:
<br /> Detection limits for conf n-nation
<br /> sampling
<br /> ELead 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 shown in applicable
<br /> reports.
<br />' 0 Lateral and l Vertical extent of soil contamination
<br /> Fy]Laterai and Vertical extent of groundwatercontamination,;i
<br /> 9. Zone of influence calculated and assumptions used for subsurface remediation Over-excavation of soil was the
<br /> system and the zone of capture attained for the soil and groundwater remediation approved remediation.
<br /> system; a
<br /> 10.Reports/information ❑Y Unauthorized Release Form ❑Y QMRs 36 from 10/98 to 10/09
<br /> �Y Well and boring logs � PAR FRP Other NFAR(11%09)
<br /> I
<br /> 11.Best Available Technology BA T used or an explanation for not USTs removal, soil over-excavation,and natural
<br /> Y gy l ) F
<br /> usingBAT, attenuation.
<br /> Y 12. Reasons why background was./Is Minor residual soil and groundwater contamination remains on-site.
<br /> ltainable using BA T; i
<br /> Y 13-Mass balance calculation of substance treated The consultant estimates 166(gallons of Tf'H removed in soil with
<br /> _ _54_gallons_of_residual_rPN_remaining_in soil.Approximately 0.33 l_bs of
<br /> versus that ie►naining; TPH remain in groundwater, which is estimated to reach WQGs in
<br /> 9 years.
<br /> Y 14. Assumptions, parameters, calculations and The regulatory agency'did not require a soil gas investigation. The
<br /> model used in risk assessments, and fate and reinstalled MW-2A pas Ised ESLs for soil. Consultant states minimal risk
<br /> transport modeling; to human health and beneficial use of groundwater
<br /> Y 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. The site structure is currently unoccupied. Residual soil
<br /> contamination remains at 15'b s.
<br /> By: JLB / Comments:In August 1989, two 1,500-gallon gasoline, one 6,500-gailon and one 10,000 diesel,and one
<br /> 1,500-gallon waste oil US Ts were removed at the subject site.Based upon 36 quarters of groundwater
<br /> [!12/'3i2009
<br /> e: monitoring showing a stable plume with declining concentrations;"the limited extent of contamination
<br /> remaining in soil and groundwater, no foreseeable changes in land use,and limited threats from soil and soil
<br /> vapor intrusion Regional Board staff concur with San Joa 'uin Coun 's Closure Recommendation.
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