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TABLE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Blincoe Trucking, 2431 E. Mariposa Rd., Stockton, San Joaquin County(RB 11391195)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2015 sensitive receptor survey reported one water
<br /> agriculture, industry and other uses within 2000 feet of the supply well 1,500'southwest of the Site. The well is not
<br /> site. threatened by the release.
<br /> Y 1 2. Site maps, to scale, of area impacted showing locations of In 3/14, two 12,000 gallon diesel USTs were removed.
<br /> any former and existing tank systems, excavation contours TPHd, 6,800 mg/kg was detected in the tank pit. Site
<br /> and sample locations, boring and monitoring well elevation maps and figures showing tank locations, excavations,
<br /> contours,gradients, and nearby surface waters, buildings, building and residual pollutants were provided in
<br /> streets, and subsurface utilities; investigation reports.
<br /> Y 3. Figures depicting lithology(cross Site lithology consists of clay, silt, and sand to 40', the total depth investigated.
<br /> section), treatments stem diagrams; Over-excavation to 25'bgs was conducted in 7/14.
<br /> Y1 4. Stockpiled soil remaining on-site or Approximately 275 yd. (436.7 tons)excavated soil was removed to 25'bgs and
<br /> off-site disposal(quantity); transported to Forward Landfill in Manteca.
<br /> 4at]e;
<br /> 5. Monitoring wells remaining on-site, No monitoring wells were installed.
<br /> 6. Tabulated results of all groundwater Depth to groundwater at two nearby USTs sites was 47'bgs in 2014.
<br /> elevations and depths to water,
<br /> - 7. Tabuiaied iesuiis of all sampling Aii data adeque ly fabu/ateal in various reports,—including naphthalene. One post
<br /> and analyses: excavation confirmation soil sample reported TPHd, 2,600 mg/kg at 20'bgs in the
<br /> ❑Y northwest pit wall. Multiple soil boring samples collected outside of the excavation
<br /> Detection limits for area did not detect TPH from 25'bgs to 40'bgs.
<br /> confirmation sampling
<br /> ❑ Lead analyses
<br /> 8. Concentration contours of contaminants found and those remaining in Petroleum pollution was detected
<br /> soil and groundwater, and both on-site and off-site: during the soil over-excavation.
<br /> ❑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 An engineered treatment system 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❑Y Unauthorized Release Form N❑ QMRS None
<br /> ❑Y Well and boring logs EPAR ❑ FRP ❑ Other
<br /> Y 1 11.Best Available Technology(BAT)used or Leak was stopped by removing tanks. Over-excavation removed majority
<br /> an explanation for not using BAT, of source of TPHd.
<br /> 12. Reasons why background was/is not Soil over-excavation removed threat to groundwater.
<br /> finable using BAT;
<br /> Y 13.Mass balance calculation of substance Mass balance of excavated soil was estimated by the consultant as
<br /> tr4ated versus that rernainin ; 11,354 lbs. (1,720 gal.)of TPHd removed.
<br /> Y 14. Assumptions,parameters, calculations San Joaquin County determined that the Site meets the LTCP criteria for
<br /> and model used in risk assessments, and commercial use. Consultant states site does not represent a significant
<br /> fate and transport modeling; environmental or health risk under current use(commercial).
<br /> Y 15. Rationale why conditions Groundwater was not encountered during investigation and over excavation.
<br /> remaining at site will not adversely Land use is not expected to change(commercial)in the foreseeable future. Due
<br /> impact water quality, health, or other to 25'bgs soil samples not impacted by TPHd and clean soil placed above 25'
<br /> beneficial uses;and bgs, the regulatory agency determined that vapor intrusion and dermal contact
<br /> were not a significant environmental or health risk under current and future
<br /> land use commercial
<br /> By: JLB Comments:In 3/14, two 12,000 gallon diesel USTs were removed at the subject site(commercial). After over-
<br /> excavation, soil at 20'below one of the tanks was impacted by TPHd at 2,600 mg/kg. Based on no
<br /> Date: concentrations of petroleum hydrocarbons detected in soil borings from 25'to 40'bgs, clean soil placed
<br /> 4/24/2015 above 25'bgs, depth to water at 47 feet bgs, and this case meets the LTCP, Regional Board staff concur with
<br /> San Joaauin Countv's Closure Recommendation.
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