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U <br /> TABLE 1 - CHECKLIST OF REQUIRED DATA <br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES <br /> + II <br /> Site Name and Location: Discovery Chevrolet Site, 1615 11th Street,Tracy,San Joaquin County <br /> Ly 1. Distance to production wells for municipal, domestic, agriculture, industry 5 wells within 2,000 It, closest:700•ft N-NE <br /> and other uses within 2000 feet of the site; (cross-gradient to downgradient),other 4 <br /> wells upgradient or side gradient. ii <br /> y� 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems; No off-site contamination -1 <br /> excavation contours and sample locations, boring and monitoring well elevation contours, indicated. <br /> gradients, and nearby surface waters, buildings, streets, and subsurface utilities; <br /> i <br /> YD 3. Figures depicting fithology(cross section), treatment system diagrams; Soil boring logs and x-sections show fine <br /> grained to(10-15)and sand boring TO <br /> FTI <br /> 4. Stockpiled soil remaining on-site or off-site disposal(quantity); 450 cubic yards of overex,soil removed to Forward <br /> landfill. <br /> j <br /> 5. Monitoring wells remaining on-site, fate,, 5 monitoring wells installed. One destroyed during overex., remaining four [ <br /> to be pressure grouted before site closure. fr <br /> 6. Tabulated results of all groundwater elevations and depths to water, Shallow groundwater approximately f0 feet bgs. <br /> yF - - <br /> y� 7.Tabulated results of all sampling and analyses: Initial soil 4,400 mg/Kg TPHg,30 mg/Kg benzene. Water sampling: <br /> FYIInitial 17,000,ug/L TPHg, 3,100µg/L benzene;after 59µg/L(TPHg)and <br /> FYI Detection limits for confirmation sampling 8.2 L benzene. Target soil removal of conc>5 } <br /> µg/ g ppm was achieved I <br /> Lead analyses during overex. <br /> N 8. Concentration contours of contaminants found and those remaining in soil Soil appears to be defined by the series of <br /> AW groundwater, and bot site and off-site: borings and excavation samples. The <br /> Lateral and Vertical extent of soil contamination downgradient edge of contaminatiorr is <br /> poorly defined by MW-4. Low <br /> Fy Lateral and ElVertical extent of groundwater contamination concentration remain in this well. <br /> NA 9.zone of influence calculated and assumptions used for subsurface WA E•- .�¢ <br /> remediation system and the zone of capture attained for the soil and <br /> groundwater remediation system; <br /> y� 10.Reports/information Y❑Unauthorized Release Form ❑y OMRs(Dates)94-98 <br /> �Y Well and boring logs �y PAR �y FRP �y Other(report name)Rpt. on Corr.Action(9/16/98) <br /> YD 11.Best Available Technology(BAT)used or an explanation for not using BAT* Overexcavation and limited groundwater <br /> pumping removed much of contamination <br /> NA ,12.Reasons why background wasls unattainable using.BAT N/A <br /> 13.Mass balance calculation of substance treated versus that remaining; Residual groundwater mass should be <br /> calculated for land use decisions <br /> NA 14.Assumptions,parameters, calculations and model used in risk N/A <br /> assessments, and fate and transport modeling; <br /> Y7 15.Rationale why conditions remaining at site will not adversely Low concentrations remain in groundwater. Soil r <br /> impact water quality, health, or other beneficial uses;and remediated by overexcavation. ' <br /> 0 16.WET or TCLP results - <br /> eyjp Comments: Low concentrations of petroleum constituents remain in groundwater below this site,primarily in the <br /> vicinity of the former USTs. Significant remediation as soil overexcavation and groundwater pumping has been <br /> Date: completed. Conditions remaining are unlikely to continue degrading water quality. The residual contaminat volume <br /> / r+' in groundwater should be calculated for future land use decisions. <br /> i <br /> I <br /> r <br />