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<br /> ABLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Sanchez Property, 1$76 Country Club Blvd., Stockton, San Joaquin County(RB#390346)
<br /> y ?. Distance to production wells for municipal, domestic, agriculture, A 201!sensitive recepforsurvey reported no water
<br /> indust and other uses within 2000 feet of the site. supply wells within 2,000'of the site.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of any In 1-89, two 1,000-Balton gasoline USTs were
<br /> former and existing tank systems, excavation contours and sample removed. The site was over-excavated to 30'bgs in
<br /> locations, boring and monitoring well elevation contours, gradients, 2-03.
<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 clay, silt, and sand to 30',
<br /> diagrams; the total depth investigated.
<br /> Y1 4. Stockpiled soil remaining onsite or off-site disposal approximately 750 yd excavated soil was transported to
<br /> (quantity); Forward Landfill in Manteca.A total of 116,535 gallons;of water `
<br /> in the excavation was treated and discharged to the sewer
<br /> y 5. Monitoring wells remaining on-site, fate, Fourteen(14)monitoring wells(MW-1 through MW-5, MW-6A fo MW-9A,
<br /> MW-6B to MW-9B,and MW-10)and two remediation wells(RIA and R2A)will
<br /> be properly destroyed. Note the five(5)soil vapor probes and four(4)
<br /> iezometers were destroyed. 4}
<br /> 6. Tabulated results of al!groundwater ' Depth to groundwater Varied Mom 6'bgs to 22"bgs. Groundwater flow
<br /> direction varied from northeast to northwest. Groundwater gradient i
<br /> elevations and depths to water,
<br /> varied from 0.0003 ftlft to 0.000087 ft/ft.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports, including closure report.
<br /> and analyses:
<br /> ,Yn Detection limits for confirmation
<br /> sampling
<br /> Lead analyses
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<br /> 8. Concentration contours of contaminants found and those remaining in soil and The extent of the identified
<br /> groundwater,and both on-site and off-site: contamination is described in the
<br /> available reports.
<br /> ELateral and ElVertical extent of soil'contamination
<br /> Lateral and Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface remediation Over-excavation and groundwater pump
<br /> system and the zone of capture:attained for the soil and groundwater remediation and treatment were the engineered
<br /> system; remediation.
<br /> 10.Reports/information � Unauthorized Release Form QMRs(69)4-93 to 5-11
<br /> Well and boring logs 10 PAR El FRP F71 Other Closure Reports(6-10, 6-11, & 10-11))
<br /> Y11.Best Available Technology(BAT) used or an explanation for not using USTs removal, over-excavation,pump and
<br /> treatment, and natural attenuation.
<br /> BAT;
<br /> .Yf.—1.2..,Reasons-why-background wads-unattainabie, Residual-soil-and-groundwater=contamination.remains-onsite t
<br /> BAT; ,
<br /> u SA?3.Mass balance calculation of substance treated Over-excavation removed 6,791 lbs of TPHg in soil. Groundwater
<br /> pump and treatment removed 2.41 gallons of TPHg. Consultant
<br /> versus that remaining; estimated residual soil mass as 685 lbs of TPHg.Approximately
<br /> 0.06 lbs of TpffS remain in groundwater.
<br /> 14. Assumptions, parameters, calculations and Soil vapor concentrations did not exceed Region 2 Environmental
<br /> Y and screening Levels(ESLs)for commercial use. Soil results failed ESLs
<br /> mode!used m
<br /> risk assessments, and fate a 9 �
<br /> Transport modeling;
<br /> for gross contamination and direct contact(TPHg)and direct contact
<br /> {benzene)at 16'bgs, below typical worker depth. Consultant states
<br /> i .site does not re resent a significant risk.
<br /> Y 15. Rationale why conditions remaining at site will Soil and groundwater contamination reportedly are limited in extent.
<br /> not adversely impact water quality, health, or other Land use(commercial)is not expected to change in the foreseeable
<br /> beneficial uses;and Ifuture. TPH is estimated to reach WQGs in 2039. i
<br /> BJLB comments n 1-89, two 1,000-gallon gasoline USTs were removed at the subject site. The site was over-
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<br /> t94 excavated in 2-03. Minor residual soil and groundwater contamination remains on-site. Based upon the
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<br /> 'Date: limited extent of contamination reported in soil and groundwater, a stable groundwater plume with declining
<br /> 1/18/2012 concentrations, no foreseeable changes in future land use(commercial), and minimal risks from soil, soli
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