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--r` TAB 9 - CHECKLIST OF REQUIRED TA
<br /> FOR NO FURTHER ACTION REQUESTS AT.UNDERGROUND TANK SITES
<br /> Site Name and Location: Universal Sweeping Services, 9113 Shaw koad, Stockton, San Joaquin County
<br /> 0 1. Distance to production wells for municipal, domestic, agriculture, A well survey was not required since groundwater did
<br /> industry and other uses within 2000 feet of the site; not appear to be impacted.
<br /> 0 2. Site maps, to scale, of area impacted showing locations of former avid existing tank One 2;000-gallon gasoline UST,
<br /> systems, excavation contours and sample locations, boring and monitoring we!!elevation one 2,000-gallon diesel,and
<br /> contours, gradients, and nearby surface waters, buildings, streets, and subsurface utilities; one 550-gallon waste oil tanks,
<br /> piping and dispensers were
<br /> removed in April 2003.
<br /> yE 3. Figures depicting lithology(cross section), treatment system diagram's; Site lithology was not reported. Stockton area
<br /> lithology typically consists of interbedded sand,
<br /> silt and clay. The total depth investigated was
<br /> 17 feet
<br /> 0 4. Stockpiled soil disposed off-site(quantity); The contaminated soil(200 yards)was retested and placed back into the
<br /> excavation on 5 July 2003.
<br /> 5. Monitoring wells remaining on-site, fate; onitoring we s were 7i6t 7ifle3 for this investigaon: i
<br /> I
<br /> ED
<br /> 6. Tabulated results of aii groundwater elevationsThe depth to water was no
<br /> ` and depths to water; ,t measured,although
<br /> nearby wells typically report groundwater from 40
<br /> to 60 feet The regional groundwater flow direction
<br /> is to the north.
<br /> 0 7 tabulated results of all sampling and analyses: initial soil analysis showed TPHd(590 mg/kg),'TPHg(1.1 mg/kg),and
<br /> Y MtBE(0.031 mg/kg). Post-excavation soll analysis showed ND for all
<br /> Detection limits for confirmation sampling constituents.
<br /> ©Lead analyses
<br /> 8. Concentration contours of contaminants found and those remaining in soil The extent of contamination is defined by
<br /> d groundwater, both on and off-site: on-site soil borings.
<br /> Y Latera!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 Based on the limited extent of soil
<br /> remediation system and the zone of capture attained for the soil and contamination,an engineered remedlation'
<br /> groundwater remediation system; system was not required at this site.
<br /> Y� 10.Reports l information 0 Unauthorized Release Form N� QMRs
<br /> Boring logs PAR FRP Other (Closure Summaryt Report, 8/03)
<br /> 11.Best Available Technology(BAT) used or an'explanation for not using BAT; f
<br /> Remove USTs, natural attenuation. G
<br /> ,,_n _"`"
<br /> tFN 12,Reasons why background wasps
<br /> unattainable using BAT, Little or no soil contamination remains on-site
<br /> N 13.Mass balance calculation of substance
<br /> treated versus that remaining; amass balance calculation was not required.
<br /> 0 14.Assumptions,parameters, calculations and model used in risk A risk assessment was not required
<br /> assessments, and fate and transport modeling,and
<br /> Y� 15. Rationale why conditions remaining at site will not adversely Soil,contamination was remedia ted, depth to
<br /> impact water quality, health, or other beneficial uses. groundwater is over 40 feet.
<br /> By: Comments: One 2,000-gallon gasoline, one 2,000-gallon diesel,'iand one 550-gallon waste oil USTs were removed from
<br /> JLB the subject site in April 2003. Multiple borings and soil overexcaGation were completed in May 2003 to delineate
<br /> contamination at this site. Maximum soil concentrations in April 2003 were TPHd(590 mg/kg),,TPHg(1.1 mg/kg), and
<br /> Date: MtBE(0.031 mg/kg). Post-excavation soil analysis in May 2003 reported ND for all constituents in soil samples taken
<br /> from the excavation and the stockpiles. 'Lead was not analyzed. Excavated soil was placed back into the excavation in
<br /> 10/14/03 July 2003. Based on the lack of soil contamination and lack of threat to groundwater, Board staff concur with San
<br /> Joaquin County's Closure Recommendation.
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