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` s wo-ABLE 1 -CHECKLIST OF REQUIRED DATA'*
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: California State University Stanislaus, 1252 Stanislaus St., Stockton, San Joaquin County
<br /> (RB#391087)
<br /> 7y 1. Distance to production wells for municipal, domestic, A 2002 sensitive receptor survey reported three water
<br /> agriculture, industry and other uses within 2000 feet of the supply wells(1,400'south, 1,500'north& 1,900'
<br /> northeast)within 2,000'of the site.None of the wells are
<br /> site. threatened by the release.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of In 7/88, one 10,000-gallon diesel,one 10,000-gallon
<br /> any former and existing tank systems, excavation contours heating fuel oil,and one 1,000-gallon gasoline USTs
<br /> and sample locations, boring and monitoring well elevation were removed.
<br /> contours,gradients, and nearby surface waters, buildings,
<br /> streets,and subsurface utilities;
<br /> Site lithology consists of clay,silt,and sand to 61', the total depth investigated.
<br /> Y 3. Figures depicting lithology(cross
<br /> section), treatment sstem diagrams;
<br /> The fate of excavated soil is not discussed in the available reports.
<br /> N 4. Stockpiled soil remaining on-site
<br /> or off-site disposal(quantity);or
<br /> (9)monitoring(MW-1 through MW-9)will be properly destroyed prior to
<br /> Wa ;5. Monitoring wells remaining on-site,
<br /> closure.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 32'bgs to 47'bgs. Groundwater flow
<br /> elevations and depths to water; direction varied from northeast to southeast. Groundwater gradient varied from
<br /> 0.0019 ft/ft to 0.015 ft/ft.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports.
<br /> and analyses:
<br /> 0 Detection limits for
<br /> confirmation sampling
<br /> ❑Y Lead analyses
<br /> LyJ 8. Concentration contours of contaminants found and those remaining in The extent of the identified contamination
<br /> soil and groundwater,and both on-site and off-site: is described in the available reports.
<br /> 0 Lateral and UJ Vertical extent of soil contamination
<br /> Lateral and MY Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface An engineered remediation was not
<br /> remediation system and the zone of capture attained for the soil and required by the regulatory agency.
<br /> groundwater remediation system;
<br /> 10.Reports/information[0 Unauthorized Release Form ❑Y QMRs(23) 12-01 to 12-11
<br /> 10
<br /> Well and boring logs PAR FRP Other Soil Gas Report, 1/13,
<br /> LTCP Report&Fate& Transport Model, 1/13
<br /> Y 11.Best Available Technology(BAT)used or an USTs removal and natural attenuation.
<br /> explanation for not using BAT;
<br /> Unable
<br /> Reasons why background was/is not It is not cost effective to implement active remediation, soil and
<br /> UUnable usin BAT; groundwater pollution will naturally degrade.
<br /> ::Y:l 13.Mass balance calculation of substance Consultant estimated residual TPH mass as 2,474.9 lbs.in soil and
<br /> treated versus that remaining; 0.0221 lbs. of TPH in groundwater.
<br /> Y714. Assumptions,parameters, calculations Site passed LTCP and Region 2 ESLs(soil vapor). Consultant states
<br /> 7
<br /> and model used in risk assessments,and fate site does not represent a significant risk.
<br /> and transport modeling;
<br /> Y
<br /> 15. Rationale why conditions remaining at Soil and groundwater contamination reportedly are limited in extent.
<br /> site will not adversely impact water quality, Land use(commercial)is not expected to change in the foreseeable
<br /> health, or other beneficial uses;and future. Consultant estimated time to reach WQGs as 2112. Groundwater
<br /> lume is stable and decreasing in concentration.
<br /> By: JLB Comments:In 7/88, one 10,000-gallon diesel,one 10,000-gallon heating fuel oil,and one 1,000-gallon
<br /> gasoline USTs were removed at the subject site. Contaminated soil discovered during a site assessment in
<br /> Date: July 2002.Residual soil and groundwater contamination remains.Based upon the limited extent of
<br /> 6/6/2013 contamination reported in soil and groundwater,a stable and very slowly declining concentration plume,no
<br /> foreseeable changes in future land use(commercial), and minimal risks from groundwater,soil vapor and
<br /> soil Regional Board staff concur with San Joaquin County's Closure Recommendation.
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