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TABLE 1 - CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> t
<br /> Site Name and Location: Tracy Cold Storage,24500 South Mac Arthur Drive,Tracy, San Joaquin County
<br /> 1. Distance to production wells for municipal, domestic, agriculture, Two water supply wells located on-site. The older
<br /> industry and other uses within 2000 feet of the site; well, designated as the South Well, is located within
<br /> the area of soil contamination.
<br /> 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems,
<br /> EDexcavation contours and sample locations, boring and monitoring well elevation contours,
<br /> gradients, and nearby surface waters, buildings,streets, and subsurface utilities;
<br /> Boring logs show predominantly silty clay soils.
<br /> Y� 3. Figures depicting lithology(cross section), treatment system diagrams; A treatment system was not installed.
<br /> 4. Stockpiled soil remaining on-site or off-site disposal(quantity); 1.522 cubic yards of soil was excavated in 7/98, then
<br /> erated and spread out on-site.
<br /> FE 5. Monitoring wells remaining on-site, fate, Ten monitoring wells were installed on-site. Five monitoring wells have been
<br /> destroyed due to excavation activities, and the remaining monitoring wells
<br /> will be destroyed pending site closure.
<br /> EYD 6. Tabulated results of all groundwater elevations and depths to water; Depth to water varies from 8 to 12 feet bgs, and
<br /> flow is to the northwest.
<br /> EY-1 7.Tabulated results of sampling and analyses: June 1999 monitoring results for MW-1A (former tank area)in Ng1l show
<br /> TPHg at 3,800, BTEX at 150, 5.3, 22, and 18, respectively. MtBE,
<br /> © Detection limits for confirmation sampling analyzed in 6196, 10/97, and 12/97, was <1.0 Ng/1 for all wells sampled.
<br /> ©Lead analyses Maximum lead analyzed from site soils is 48 mg/kg.
<br /> y� 8. Concentration contours of contaminants found and those remaining in soil Lateral and vertical extent of soil and
<br /> and groundwater, and both on-site and off-site: groundwater contamination defined.
<br /> © Lateral and 0 Vertical extent of soil contamination
<br /> Lateral and 71 Vertical extent of groundwater contamination
<br /> 9.Zone of influence calculated and assumptions used for subsurface A remediation system was not installed at
<br /> remediation system and the zone of capture attained for the soil and this site.
<br /> groundwater remediation system;
<br /> y� 10.Reports/information IV] Unauthorized Release Form QMRs(5/95 to 9/99)
<br /> F1 Well and boring logs FN IPAR FRP Other(QMR and Case Closure Request, 9/99)
<br /> 11.Best Available Technology(BAT) used or an explanation for not using BAT, Excavate contaminated soils, applied 510
<br /> Y pounds of ORC to backfill material.
<br /> 12.Reasons why background wasris Some contaminated soil remains in place. Shallow water levels release
<br /> unattainable using BAT,
<br /> contamination into groundwater.
<br /> An estimated 15,000 pounds of contaminated soils were identified on-site, and
<br /> El13.Mass balance calculation substance 11,450 pounds were removed by excavation activities. This represents a 76%
<br /> treated versus that remaining;; reduction in mass.
<br /> 14.Assumptions,parameters, calculations and model used in risk A risk assessment was not completed.
<br /> Qassessments, and fate and transport modeling;
<br /> Y 15. Rationale why conditions remaining at site will not adversely QMRs document the reduction of petroleum
<br /> EJimpact water quality, health, or other beneficial uses;and hydrocarbons in on-site monitoring wells.
<br /> By: Comments: One UST was removed in the 1970's, initial soil borings were completed in 8/94, and over excavation of the
<br /> tank pit soils were completed in 7/98. Groundwater contamination has dropped significantly since contaminated soils were
<br /> excavated. Contamination is limited to on-site soil and groundwater. MtBE has not been identified at this site. Two water
<br /> supply wells are located downgradient and within 100 feet of the former UST area. The older well designated as the
<br /> Date: "South Well"is located within the area of soil and groundwater contamination, and does not have well construction
<br /> information available. Sampling results were non detect for both water supply wells sampled in 6/99. Based on the
<br /> existing water supply well located within the soil and groundwater contamination area, San Joaquin County's closure
<br /> °p recommendation is not appropriate at this time.
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