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<br />y TABLE 1 - CHECKLIST OF REQUIRED DATA
<br />FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br />Site Name and Location:
<br />Former Morita Brothers, 814 E. Charter Way, Stockton, San Joaquin County (RB #390703)
<br />HI1. Distance to production wells for municipal, domestic,
<br />A 2009 sensitive receptor survey stated no water supply
<br />agriculture, industry and other uses within 2000 feet of the site.
<br />wells were observed within 2000' of the site. The nearest
<br />public supply well was listed by DWR as 1350' southwest
<br />cross radlent) of the site.
<br />Y1 2_ Site maps, to scale, of area impacted showing locations of
<br />Two 5,000 -gallon and one 2,000 -gallon gasoline, and one
<br />any former and existing tank systems, excavation contours and
<br />500 -gallon waste oil USTs were removed 12191.
<br />sample locations, boring and monitoring well elevation
<br />contours, gradients, and nearby surface waters, buildings,
<br />streets, and subsurface utilities;
<br />Y 3. Figures depicting lithology (cross section), treatment system
<br />Site lithology consists of clay, silt, and sand to 82', the
<br />diagrams;
<br />total depth investigated.
<br />_Y1 4. Stockpiled soil remaining on-site or off-site disposal {quantity);
<br />Approximately 760 cubic yards of soil excavated 5193
<br />during the UST over -excavation was transported to
<br />Forward Landfill in Manteca.
<br />y 5. Monitoring wells remaining on-site, fate;
<br />Nineteen monitoring wells (MW -1 through MW -7, MW -11, MW -104, MW -106 to
<br />MWA 11, MW -202, MW -208 through MW -290) will be properly abandoned.
<br />6. Tabulated results of all groundwater
<br />Depth to groundwater varied from 30' to 54' bgs. Groundwater flow
<br />elevations and depths to water,
<br />direction varied from northeast to southeast. Groundwater gradient
<br />varied from 0.0012 to 0.018 fUfL.
<br />7. Tabulated results of all sampling
<br />All data adequately tabularized in various reports, including closure report.
<br />and analyses:
<br />0 Detection limits for confirmation
<br />sampling
<br />QY Lead analyses
<br />8. Concentration contours of contaminants found and those remaining in soil and
<br />The extent of the identified
<br />groundwater, and both on-site and off-site:
<br />contamination shown in applicable
<br />Y Lateral and 0 Vertical extent of soil contamination
<br />reports.
<br />Lateral and FiVertical extent of groundwater contamination
<br />9. Zone of influence calculated and assumptions used for subsurface remediation
<br />An engineered remediation was not
<br />system and the zone of capture attained for the soil and groundwater remediation
<br />required by the lead agency.
<br />'System"
<br />10. Reports 1 info►mation Unauthorized Release Form n Rs 56 from 101 to 111 8
<br />a Well and boring logs � PAR n FRP Other Soil and Soil Gas Investigation (4108)
<br />Site Summaq Closure Re ori 9/09
<br />Y 11, Best Available Technology (BAT) used oran explanation fornot using
<br />UST removal, over-excavation,.and natural
<br />BAT:
<br />attenuation.
<br />Y 12. Reasons why background was/rs unattainable
<br />Minor residual soil and groundwater contamination remains on-site.
<br />BAT,
<br />Y__1 13. Mass balance calculation of substance treated
<br />The consultant estimates the remaining contaminant mass in
<br />versus that remaining;
<br />groundwater as 0.01 gallons of TPHg in 11/08.
<br />Y 14. Assumptions, parameters, calculations and
<br />The 2008 soil vapor sample results show Region 2 ESLs were not
<br />model used in risk assessments, and fate and
<br />exceeded. The consultant estimated time for groundwater to reach
<br />transport modefn ;
<br />WQGs as 5 to 8 years for TPH , and 4 to 17 years for MTBE.
<br />:y:] 15. Rationale why conditions remaining at site will
<br />Soil and groundwater contamination reportedly are limited in extent.
<br />not adversely impact water quality, health, or other
<br />Land use (commercial} is not expected to change in the foreseeable
<br />beneficial uses; and
<br />future.
<br />By, JL r--
<br />Comments: Two 5,000 -gallon and one 2,000 -gallon gasoline, and one 500 -gallon waste oil USTs were
<br />removed 12/91 from the subject site. Approximately 760 cubic yards of soil were over -excavated 5193 and
<br />transported offsite for disposal. Based upon 56 quarters of groundwater monitoring showing a stable plume
<br />Date:
<br />1111012009
<br />with declining concentrations, the limited extent of contamination remaining in soil and groundwater, no
<br />foreseeable changes in land use and no soil vapor ESLs exceeded, Regional Board staff concur with San
<br />Joaquin County's Closure Recommendation.
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