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<br /> TAS 1 -CHECKLIST OF REQUIRED kTA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: City of Lodi Safety Blvd.,230 Elm Street, Lodi,San Joaquin County
<br /> Q1.Distance to production wells for municipal, domestic, agriculture, A well survey in 2001 shows two public water supply
<br /> industry and other uses within 2000 feet of the site, wells located approximately 1500 feet north and 2000
<br /> feet southwest of the site. '
<br /> 0 2. Site maps, to scale, of area impacted showing locations of former and existing tank One 12,000-gallon gallon gasoline
<br /> systems, excavation contours and sample locations, boring and monitoring well and one 2,000-gallon diesel USTs
<br /> elevation contours, gradients, and nearby surface waters, buildings, streets, and were removed in 2105.
<br /> subsurface utilities;
<br /> a3.Figures depicting lithology(cross section), treatment system diagrams;. Site lithology consists of silt and sand to 59 feel;
<br /> the total depth Investigated.
<br /> M4. Stockpiled soil disposed off-site(quantity); Approximately 42 cubic yards of excavated soil and gravel was
<br /> transported by the City of Lodi to another City facility for disposal.
<br /> 0 5.Monitoring wells remaining on-site, fate; Two monitoring wells(MW-1 through MW-2))installed for a prior investigation
<br /> investig�l ( 4
<br /> _ rren�e anal `hra , Ma j. the welts were properly -
<br /> destroyed per San Joaquin County site closure letter(Case 1)dated
<br /> 8 July 2005.
<br /> 0 6. Tabulated results of all groundwater elevations and depths to water, The depth to water varied from 45 feet(1978)to 35
<br /> feet(1998),and the regional groundwater flow
<br /> 0 Y direction is to the south and southwest
<br /> 7.Tabulated results.of all sampling and analyses: In 2/05,soil results were 6.7 mg/kg for TPHg, 0.018 mg/kg for
<br /> Detection limits for confirmation sampling ethylbenzene,0.171 mg/kg for xylenes,and 18.8 mg/kg for MISE. After
<br /> over-excavation,all soil results were ND. Groundwater monitoring
<br /> Lead analyses results were all ND in 4105.
<br /> DY8. Concentration contours of contaminants found and those remaining in soil
<br /> aad groundwater, both on-.site and off-site: The extent of contamination is defined by
<br /> Rateral
<br /> ateral and Vertical extent of soil contamination on-site soil borings and monitoring wells.
<br /> and Vertical extent of groundwater contamination
<br /> Y� 9.Zone of influence calculated and assumptions used for subsurface
<br /> remediation system and the zone of capture attained for the soil and Based on the limited extent of soil
<br /> groundwater remediation system; contamination,an engineered remed/ation
<br /> system was not required at this site.
<br /> Q 10.Reports/information Unauthorized Release Form QMRs no.
<br /> �oring logs rI PAR N❑ FRP Other Site Excavation Report and Site Closure Request
<br /> 0 11.Best Available Technology(BAT)used or an explanation for not using BAT, Removelgrout in place USTs and natural
<br /> attenuation.
<br /> .2 Rbasons-wl►y background_waslis_ _ v
<br /> -Groundwa-&icon'i`am rYwa3�tottavnd d�7rronftarhr�-No-s t---
<br /> unattainable using BAT, '
<br /> contamination remains on-site.
<br /> ON 1 13.Mass balance calculation of substance
<br /> treated versus that remaining; Since no contamination remains onsite,mass balance was not required for soil
<br /> or groundwater.
<br /> 0 14.Assumptions,parameters, calculations and model used in risk
<br /> assessments, and fate and transport modeling,and A risk assessment was not required.
<br /> 0 15. Rationale why conditions remaining at site will not adversely Soil contamination is not present,and based on one
<br /> impact water quality, health, or other beneficial uses. groundwater sampling event, contamination has not
<br /> leached to groundwater.
<br /> By: Comments: One 12,000-gallon gallon gasoline and one 2,000-gallon diesel USTs were removed in 2/05. In 2105,soil
<br /> ,R,$ results were 6.7 mg/kg for TPHg, 0.018 mg/kg for ethylbenzene,0.171 mg lkg for xylenes, and 18.8 mg/kg for MtBE. After
<br /> over-excavation, all soil results were ND. Groundwater monitoring results were all ND in 4105. Based on the removal of
<br /> Date: all soil contamination and no contamination present in groundwater, Regional Board staff concur with San Joaquin
<br /> County's Closure Recommendation.
<br /> 7/25/05
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