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•.. kBLE 1 -CHECKLIST OF REQUIRED DAWN
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Lodi Downtown Theater, 107 N.School St., Lodi,San Joaquin County, LUSTIS#390144
<br /> 7_1 1. Distance to production wells for municipal, domestic, agriculture, One active municipal supply well is located 550 feet
<br /> industry and other uses within 2000 feet of the site; north(upgradient)of the site. The site is within the
<br /> Lodi Dry Cleaners PCE-TCE plume,which has
<br /> im acted and closed two additional nearby wells.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of former Two 500-gallon regular and one 2,000-gallon
<br /> unleaded gasoline, one 55-gallon and one
<br /> and existing tank systems, excavation contours and sample
<br /> locations, boring and monitoring well elevation contours, gradients, 250 gallon waste oil UST were removed 9/87.
<br /> and nearby surface waters, buildings, streets, and subsurface
<br /> utilities;
<br /> Y 3. Figures depicting lithology(cross section), treatment system Site lithology consists of sand,silt,and clay. The
<br /> diagrams; total depth investigated was 60 feet.
<br /> EK: 4. Stockpiled soil disposed off-site(quantity); Approximately 1,400 cubic yards of soil was removed. The fate of the
<br /> soil was not revealed.
<br /> Y 5. Monitoring wells remaining on-site, fate;---- Eight monitoring wells-(MW--1 through,MW.-8),seven air sparging,wells(SW-1
<br /> through SW-7),and eight soil vapor extraction wells(VW-1 through VW-8)
<br /> installed for this investi ation and remediation will be abandoned.
<br /> Y 6. Tabulated results of all groundwater elevations and depths to The depth to water varied from 35 to 55 feet. The
<br /> water; direction of groundwater was towards the south.
<br /> 7.Tabulated results of all sampling and In 10/98,maximum soil boring results were: TPHg, 11,000 mg/kg; TPHd,
<br /> analyses: 1,100 Ng/kg;benzene,42 mg/kg;toluene,420 Ng/kg;ethylbenzene,
<br /> 180 Ng/kg;and xylenes, 840 Ng/kg. In 1/06,maximum soil boring results
<br /> Y®Detection limits for confirmation sampling were: TPHg,4.6 mg/kg and xylenes, 0.058 mg/kg. Maximum
<br /> Lead analyses groundwater results in 12/98 were: TPHg,45,000 pg/L; TPHd, 1,100 Ng/L;
<br /> benzene, 5,000 Ng/L;toluene, 5,400 Ng/L;ethylbenzene, 1,200 Ng/L;and
<br /> xylenes, 5,700 pg/L. In 9/06, maximum groundwater results were:
<br /> benzene, 9.9 /L;eth (benzene,3 /L;and xylenes, 6.6 pgIL.
<br /> Y 8. Concentration contours of contaminants found and those remaining The extent of contamination was defined by soil
<br /> 'n soil and group ter, both on-site and off-site: borings,grab groundwater samples,and
<br /> Y Lateral and Y Vertical extent of soil contamination monitoring wells.
<br /> Lateral and Vertical extent of groundwater contamination
<br /> Y 9. Zone of influence calculated and assumptions used for subsurface An engineered remediation system consisting of
<br /> remediation system and the zone of capture attained for the soil and soil vapor extraction and air sparging was
<br /> groundwater remediation system; Irequired by SJCEHD.
<br /> Y 10.Reports/information 0 Unauthorized Release Form 18 QMRs(12/98 to 9/06)
<br /> LJ Boring togs El PAR Yj FRP Other: Closure Report
<br /> Y 11.Best Available Technology(BAT)used or an explanation for not Remove USTs, SVE/AS,and natural attenuation.
<br /> usingBAT,'
<br /> Y 12.Reasons why background wasfis unattainable using BAT,' Minor soil and groundwater contamination remains on-site.
<br /> The consultant did not estimate remaining mass in soil
<br /> N 13.Mass balance calculation of substance treated versus that and groundwater.
<br /> remaining;
<br /> Y The 1/06 soil confirmation results do not exceed Region 2 ESLs.
<br /> 14.Assumptions, parameters, calculations and model
<br /> Groundwater exceeds WQOs for benzene.
<br /> used in risk assessments, and fate and transport
<br /> modeling;and
<br /> Y 15. Rationale why conditions remaining at site will not Soil contamination is limited in extent. Since 1998, 18 quarters of
<br /> adversely impact water quality, health, or other groundwater monitoring data show declining concentrations for
<br /> beneficial uses. petroleum hydrocarbons.
<br /> By: Comments: Two 500-gallon regular and one 2,000-gallon unleaded gasoline, one 55-gallon and one 250 gallon waste
<br /> JLB oil UST were removed 9/87 from the subject site. An engineered remediation system consisting of soil vapor extraction
<br /> and air sparging was required by SJCEHD. Minor soil and groundwater contamination remains on-site. The 1/06 soil
<br /> confirmation results do not exceed Region 2 ESLs. Groundwater exceeds WQOs for benzene. Based on the fact that
<br /> Date: the vertical and lateral extent of the groundwater plume was delineated, the groundwater plume is stable, active
<br /> remediation was effective, and there are decreasing petroleum hydrocarbons concentrations in all groundwater
<br /> 10/2/06 monitoring wells, Regional Board staff concur with San Joaquin County's Closure Recommendation.
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