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TABizE 1 - CHECKLIST OF REQUIRED bATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Ted Peters Trucking, 1985 Yosemite Avenue, Manteca, San Joaquin County
<br /> ETI 1. Distance to production wells for municipal, domestic, agriculture, Sixtyprivate wells are located within 2000 feet of
<br /> industry and other uses within 2000 feet of the site; the sinine te. The closest private well, 1919 W.Yosemite j
<br /> Ave., 160 feet northeast and crossgradient from the JI
<br /> site,was not impacted.
<br /> One 1,000-gallon gasoline UST
<br /> 2. Site maps, to scale, of area impacted showing locations of former and existing tank was removed in July 1997.
<br /> systems, excavation contours and sample locations, boring and monitoring well elevation
<br /> contours, gradients, and nearby surface waters, buildings, streets, and subsurface utilities;
<br /> FTI
<br /> Site lithology consists of sand,silt and clay to
<br /> 3. Figures depicting lithology(cross section), treatment system diagrams; 26 feet, the Iotal depth investigated.
<br /> PTI
<br /> Excavated soil(unknown quantity)was returned to the tank pit lined with
<br /> 4. Stockpiled soil disposed off-site(quantity);
<br /> Pyv y o! rn !plasticPyl
<br /> 5. Monitoring wells remaining on-site, fate; Three monitoring wells were installed for this investigation. The wells(MW-1
<br /> through MW-3))will be properly destroyed pending site closure.
<br /> �y [ to-f5-feet—The
<br /> - —� ' 6. Tabula`fea7esults of all groundwater e7r vatior►"s and`depths-to-water; ThQ_derth.to,w3ter_varied fr_o+r�,10 to_15 feef.,7hQ
<br /> groundwater flow direction is west
<br /> 0 7.Tabulated results of all sampling and analyses: In 1997 and 1999,soil concentrations were: TPHg(298 mg/kg),benzene
<br /> Y (0.204 mg/kg), nLC lead(14 mg/kg),and MtBE((83.5 mg/kg).
<br /> Detection limits for confirmation sampling Groundwater monitoring concentrations in 1/02 were X50 pg/L for
<br /> Lead analyses TPHg, <0.3 pg/Lfor ethylbenzene, toluene and xylenes,and X50 pg1L
<br /> for TTLC lead.
<br /> 0 8. Concentration contours of contaminants found and those remaining in soil The extent of contamination is defined by
<br /> and groundwater, both on-site and off-site: on-site soil borings and monitoring wells.
<br /> ®Y Lateral 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 n the limited extent of soil
<br /> remediation system and the zone of capture attained for the soil and I contamination,an engineered remediation
<br /> system was not required at this site.
<br /> groundwater remediation system;
<br /> 0 10.Reports/information YT Unauthorized Release Form El five QMRs(7/99 to 1/02)
<br /> 0 Boring logs PAR 0 FRP F1 Other
<br /> 11.Best Available Technology(BAT) used or an explanation for not using BAT, Remove UST, natural attenuation.
<br /> 12.Reasons why background warms Decreasing concentrations have been attained at all monitoring wells. Minor
<br /> unattainable using BAT, soil contamination rem/ins on-site.
<br /> .13.Mass balance calculation of substance Mass balance was not Calculated for soil or groundwater. w—
<br /> treated versus that remaining
<br /> 14.Assumptions,parameters, calculations and model used in risk A risk assessment was not required.
<br /> assessments, and fate and transport modeling;and
<br /> 0 15. Rationale why conditions 'remaining at site will not adversely Soil contamination is limited in extent, and based on five
<br /> impact water quality, health, or other beneficial uses. sampling events, contamination is not continuing to
<br /> teach to groundwater. Groundwater monitoring shows a
<br /> decreasing trend in concentrations.
<br /> By: Comments: One 1,000-gatlon gasoline UST was removed from the subject site in July 1997. Multiple soil borings and
<br /> JLg three monitoring wells were completed in 1999 to delineate and monitor contamination at this site. Soil results from 1997
<br /> and 1999 were: TPHg(298 mg/kg), benzene(0.204 mg/kg), iTLC lead(14 mg/kg), and MtBE((83.5 mg/kg). Maximum
<br /> Date: groundwater concentrations declined, from:520 pg/L to <50 pg/L for TPHg, 1.5 pg/L to <0.3 pg/L for toluene, 35 pg/L to
<br /> <0.3 pg1L for ethylbenzene, and 160 pg/L to<0.3 pg/L for xylenes. TTLC lead in groundwater was X50 pg/L. Fuel
<br /> 7/22/03 oxygenates and lead'scavengers were not detected in groundwater. Although 69 private wells are located within 2000
<br /> feet of the site, the groundwater plume appears stable, with declining concentrations..Based on the limited extent of soil
<br /> contamination and decreasino contaminant concentrations in laroundwater. Board staff concur with San Joaauin Countv's
<br />
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