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TAI 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHEI CTION REQUESTS AT UNDERGROUND TAWSITES
<br /> Site Name and Location: Teresi Trucking,900%East Victor Road, Lodi, San Joaquin County
<br /> Four domestic wells are within 2,000 feet of the
<br /> 1. Distance to production wells for municipal, domestic, agriculture, industry .� site. The nearest downgradient well is about
<br /> and other uses within 2000 feet of the site; 11,100 feet south of the former tanks. The only
<br /> on-site domestic well was destroyed in 1996.
<br /> ❑ 2. Site maps, to scale, of area impacted showing locations of former and existing,tank systems, In 1995, the dispenser island,
<br /> p p 9 two diesel tanks(10,000 and
<br /> excavation co.Ontours and sample locations, boring and monitoring well elevation contours, 12,000-gallon),and one 5,000
<br /> gradients, and nearby surface waters, buildings, streets, and subsurface utilities;, gallon gasoline tank were
<br /> removed from the site
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<br /> `` No treatment system was used.
<br /> 3. Figures depicting lithalogy(cross section}, treatment system diagrams; I
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<br /> Approximately 300 cubic yards of soil was disposed of off-site
<br /> 4. Stockpiled soil remaining on-site or off-site disposal(quantity); and 300 cubic yards'were returned to the tank pit.
<br /> 5. Monitoring wells remaining on-site, fate; Three monitoring wells were installed of the�'site. San Joaquin County has proposed I
<br /> destroying the wells pending Regional Board closure concurrence.
<br /> Groundwater I�fevations varied.between,50 and-57 feet _.
<br /> ❑ 6. Tabulated results of all groundwater elevations and depths to water; bgs, with a southerly flow direction.
<br /> Elevated levels of TPHd, TPHg,and TEX were defected in soil samples from YI
<br /> 7. Tabulated results of all sampling and analyses:
<br /> beneath the dispenser. Moderate to��low levels of TPHd and TEX were detected
<br /> Y❑ Defection limits for confirmation sampling in three of four soil borings.'MTBE was not detected in water samples from the
<br /> L J Lead analyses borings using EPA Method 1 602. Groundwater monitoring began,and in June 1999,low.TEX concentration's,MTBE at 871rg/l,and TAME at 5.3 yg/l were ;
<br /> detected in one well.Subsequent samples were non-detect.
<br /> FTI and
<br /> Concentration contours of contaminants found and those remaining in soil
<br /> and groundwater, and both on-site and off-site:
<br /> Lateral and Vertical extent of soil contamination e
<br /> Lateral and Y❑ Vertical extent of groundwater contamination j
<br /> 9. Zone of influence calculated and assumptions used for subsurface
<br /> The limit of the soil excavation is depicted in the
<br /> E-1Closure
<br /> system and the zone of capture attained for the soil and Closure Report.
<br /> groundwater remediation system; I
<br /> ❑''10.Reports/information El Unauthorized Release Form NA QMRs(Dates) 2/96 -8199
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<br /> Welland boring logs SPAR Y❑ FRP Other(report name);;Closure Report
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<br /> 11.Best Available Technology(BAT) used or an explanation for not using BAT, The'tanks and dispenser island were removed
<br /> ' ii from the site.
<br /> i_:J 12.Reasons why background was/is unattainable using BAT;
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<br /> ❑ 13.Mass balance calculation of substance treated versus that remaining; Based oil February1996 monitoring data,less than
<br /> 01. gallons of diesel remains in groundwater.
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<br /> N❑ 14.Assumptions,parameters, calculations and model used in risk
<br /> assessments, and fate and transport modeling;
<br /> El 15.Rationale why conditions remaining at site will not adversely Investigations show that contaminants did not significantly
<br /> impact groundwater nor migrate more than 10 feet from the site.
<br /> impact water quality, health, or other beneficial uses;and
<br /> . ❑ 16. WET or TCLP results
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<br /> By: Comments: During the removal of the dispenser island,elevated levels of TPHd and TEX were detected in soil samples. The
<br /> y dispenser location was over-excavated to a depth of 25 feet. From December 1995j1to February 1996,four soil borings were
<br /> Dat installed in the excavated area. High concentrations of TPHg and TPHd and low levels of TEX were detected in soil samples from
<br /> three of the borings. Water samples from one of the boring revealed moderate levels of TPHg, TPHd, and TEX. A water sample
<br /> also was analyzed for MTBE using EPA Method 602;however, MTBE was hot detected. Six quartans of groundwater occurred from
<br /> / February 1996 to August 1999. With the exception of June 1999, water samples essentially were non-detect. During the June 1999
<br /> sampling event,low levels of TPHd, BTX MTBE,and TAME were detected in water,samples from one moniforing well;however,
<br /> the consultant and County staff believes these detections are erroneous because contaminants were not detected during prior and
<br /> subsequent sampling events. The nearest downgradient supply well is over 1,000 feet from the site. Based on the minimal impacts
<br /> to groundwater and the distance to the nearest receptor,staff concurs with San Joaquin County closure recommendation.
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