|
BLE 1 -CHECKLIST OF REQUIRED DATA ♦�
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Prem Dor/Masonite,433 Scotts Ave., Stockton,San Joaquin County(RB#391123)
<br /> Y 1. Distance to production wells for municipal, domestic, A 2004 sensitive receptor survey found no water supply
<br /> agriculture, industry and other uses within 2000 feet of the site. wells within 2,000'of the Site.Mormon Slough is located
<br /> 750'north of the Site.
<br /> Y 2. Site maps, to scale, of area impacted showing locations of In March 2002, two 350-gallon gasoline USTs were
<br /> any former and existing tank systems, excavation contours and removed. The NFAR also lists one 500-gallon and one
<br /> sample locations, boring and monitoring well elevation 1,000-gallon gasoline and one 2,000-gallon diesel USTs
<br /> contours, gradients, and nearby surface waters, buildings, removed 12/86, and one 1,000-gallon diesel UST was
<br /> streets, and subsurface utilities; abandoned in place in 1976.
<br /> Y 3. Figures depicting lithology(cross section), treatment system Site lithology consists of clay,silt,and sand to 100', the
<br /> diagrams; total depth investigated.
<br /> Y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Approximately 521 tons of over-excavated soil was
<br /> transported to Forward Landfill in Manteca.
<br /> YJ 5. Monitoring wells remaining on-site, fate; Seven monitoring wells(MW-1 through MW-7)will be properly abandoned.
<br /> 6. Tabulated results of all groundwater Depth to groundwater varied from 14'to 20'bgs. Groundwater flow
<br /> elevations and depths to water, direction varied from northeast to east. Groundwater gradient varied
<br /> from 0.002 to 0.022 Wt.
<br /> 7. Tabulated results of all sampling All data adequately tabularized in various reports,inc7u mg closure report.
<br /> and analyses:
<br /> Detection limits for confirmation
<br /> sampling
<br /> ❑Y Lead analyses
<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 shown in applicable
<br /> reports.
<br /> F Lateral and 0 Vertical 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 of soil was the
<br /> system and the zone of capture attained for the soil and groundwater remediation approved remediation.
<br /> system;
<br /> 10.Reports/information �Y Unauthorized Release Form ❑Y QMRS 23 from 10/03 to 5/09
<br /> FY Well and boring logs 1Y PAR ❑Y FRP ❑Y Other NFAR(11/09);SVIIR(3/10)
<br /> Y11.Best Available Technology(BAT)used or an explanation for not USTs removal,soil over-excavation,and natural
<br /> usin BAT, attenuation.
<br /> 12. Reasons why background wasris Minor residual soil and groundwater contamination remains on-site.
<br /> Y
<br /> ttainable using BAT,
<br /> Y 13.Mass balance calculation of substance treated The consultant estimates 4,292 lbs. of TPH removed from soil with
<br /> versus-that remaining; 1,005 lbs. of residual TPH remaining in soil.Approximately 11.41 lbs. of
<br /> TPH were initially present in groundwater and 0.09lbs. remain in
<br /> groundwater, which is estimated to reach WQGs in 1 year.
<br /> 7Y14. Assumptions,parameters, calculations and A March 2009 soil gas investigation did pass a Tier 2 J&E Model,and
<br /> model used in risk assessments, and fate and shows low risk from vapor intrusion to an apartment complex that is
<br /> transport modelin ; approximately 40'south of the excavation.
<br /> Y 15. Rationale why conditions remaining at site Soil and groundwater contamination reportedly is limited in extent.
<br /> will not adversely impact water quality, health, or Land use(commercial)is not expected to change in the foreseeable
<br /> other beneficial uses;and future. Vapor intrusion risk has been addressed.A door manufacturing
<br /> facility currently occupies the Site. The majority of the residual soil
<br /> contamination remains below 20'b s.
<br /> By: JL� Comments:In March 2002, two 350-gallon gasoline USTs were removed from the subject site. The NFAR also
<br /> lists one 500-gallon and one 1,000-gallon gasoline and one 2,000-gallon diesel USTs removed 12/86, and one
<br /> Date: 1,000-gallon diesel UST was abandoned in place in 1976.Based upon 23 quarters of groundwater monitoring
<br /> 7/22/2009 showing a stable plume-with declining concentrations, the limited extent of contamination remaining in soil
<br /> and groundwater,no foreseeable changes in land use, and limited threats from soil and soil vapor intrusion,
<br /> Regional Board staff concur with San Joaquin County's Closure Recommendation.
<br />
|