SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

TABL;,.,,, - CHECKLIST OF REQUIRED D.,..a FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES Site Name and Location: Wal-Mart#2025, 3010 Grant Line Road, Tracy, San Joaquin County FE1. Distance to production wells for municipal, domestic, agriculture, A formal sensitive receptor survey was not completed. industry and other uses within 2000 feet of the site; The consultant states that no sensitive receptors were observed within 2,000 feet of the site. ❑ 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems, One 1,000-gallon waste oil Y excavation contours and sample locations, boring and monitoring well elevation contours, UST was removed in gradients, and nearby surface waters, buildings, streets, and subsurface utilities; august 1998. Site maps are provided. M3. Figures depicting lithology(cross section), treatment system diagrams; Soil borings show stiff clay to four feet, and medium stiff clay and silt to 16 feet. 4. Stockpiled soil remaining on-site or off-site disposal The disposition of excavated soils was not presented. p g p (quantity); LE5. Monitoring wells remaining on-site, fate; Groundwater was not sampled, and monitoring wells were not installed. N 6. Tabulated results of ail groundwater elevations and depths to wafer' Depth to wafer was measured at 16 feet. The groundwater flow direction is unknown. Fy 7. Tabulated results of all sampling and analyses: Maximum tank pit excavation samples in mg/kg collected at 9 feet YCI Detection limits for confirmation sampling show TPHg at 16, ethyl benzene at 0.22,xylenes at 1.08, and lead at 4. June 2000 maximum soll boring results show xylenes at 0.0039 mg/kg. F Lead analyses All other constituents including MtBE and other fuel oxygenates were non-detect at acceptable detection limits. Y08. Concentration contours of contaminants found and those remaining in soil and groundwater, and both on-site and off--site: Lateral and vertical extent of soil Lateral and 0 Vertical extent of soil contamination contamination is defined. Groundwater was F1Lateral and Vertical extent of groundwater contamination not analyzed. 9. Zone of influence calculated and assumptions used for subsurface A remediation system was not operated at 0 remediation system and the zone of capture attained for the soil and this site. groundwater remediation system; 10.Reports/information y❑ Unauthorized Release Form FN I QMRs 0 Boring logs F PAR FRP 171Other(Site Characterization Report) 0 11.Best Available Technology(BAT) used or an explanation fornot using BAT; Remove USTs, natural attenuation. '- 112.Reasons why background wasris unattainable using BA T- Petroleum hydrocarbons remain in on-site soils near the former UST. f 7N 13.Mass balance calculation of substance treated versus that remaining; A mass balance was not completed. 14.Assumptions, parameters, calculations and model used in risk assessments, and fate and transport modeling; A risk assessment was not completed. FY 1 15. Rationale why conditions remaining at site will not adversely Contamination is limited to soil at the former UST. impact water qualify, health, or other beneficial uses;and Contamination will naturally attenuate. By: Comments: The site is a Wal-Mart department store. One 1,000-gallon waste oil UST was removed from the site in August 1998, and tank pit samples showed soil contamination under the concrete pedestal at 9 feet below ground surface. In June 2000, four soil borings were completed around the former UST to a total depth of 16 feet, and the eight soil samples showed only xylenes at 0.0039 mg/kg in one boring at 15.5 feet. All other constituents including MtBE and other D te: fuel oxygenates were non-detect. Due to no staining or odor in soil borings, groundwater was not sampled for analysts, q�Ji fit and monitoring wells have not been installed. Based on the limited contamination in soil and the lack of sensitive I receptors, Board staff concur with San Joaquin County's closure recommendation.