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T <br /> TAbeE 1 - CHECKLIST OF REQUIRED'e'ATA <br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES <br /> Site Name and Location: Moresco Property, 16865 Gawne Road,Stockton, San Joaquin County 7_1 <br /> Ej1. Distance to production wells for municipal, domestic, agriculture, industry One domestic well on-site identified within <br /> and other uses within 2000 feet of the site; 200'east of former tank pit No indication <br /> of an off-site well survey. <br /> 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems, <br /> excavation contours and sample locations, boring and monitoring well elevation contours, <br /> gradients, and nearby surface waters, buildings, streets, and subsurface utilities; <br /> 3. Figures depicting lithology(cross section), treatment system diagrams; Lithology figures provided. -Soil vapor <br /> extraction system used. <br /> 4. Stockpiled soil remaining onsite or off-site disposal(quantity); <br /> 5. Monitoring wells remaining on-site, fate; One well in-place for on-going monitoring program. <br /> L�J 6. Tabulated results of all groundwater elevations and depths to water; Groundwater elevations vary from 89'to 110'. <br /> Gradient and flow direction unknown. <br /> FY 1 7. Tabulated results of all sampling and analyses: Elevated levels of TPHg and BTEX in soil during tank removal and 1994 <br /> —1995 soil borings to 70'bgs. MtBE at 110 pg/kg and TAME at 15 pg/kg <br /> 71 Detection limits for confirmation sampling detected in soil at 60'bgs during MW-1 installation. TPHg and BTEX <br /> ElLead analyses were ND in soil and ground water in 1999: <br /> 0 8. Concentration contours of contaminants found and those remaining in soil Soil contamination defined laterally to tank <br /> Ind groundwater, and both on-site and off-site: vicinity and vertically to 70'bgs. Only one <br /> Lateral andy� Vertical extent of soil contamination ground water monitoring well(MW-1) <br /> NA Lateral and NA Vertical extent of groundwater contamination installed Groundwater sample was ND. <br /> 9.Zone of influence calculated and assumptions used for subsurface Soil vapor extraction system operated from <br /> remediation system and the zone of capture attained for the soil and 11/97— 1/98. Estimated 85 gallons of fuel <br /> groundwater remediation system; removed from subsurface. <br /> 10.Reports/information E] unauthorized Release Form a QMRs(Dates) Two ground water samples:4/8/99—5/19/99 <br /> 0 Welland boring logs EIPAR El FRP q Other(report name) <br /> 11.Best Available Technology(BAT) used or an explanation for not using BAT, soil vapor extraction used from 11197— <br /> 1/98. <br /> 12.Reasons why background wasps unattainable using BAT, <br /> Q13.Mass balance calculation of substance treated versus that remaining; Estimated mass of 1,144 lbs before SVE;85 <br /> gallon of fuel was removed. <br /> 14.Assumptions,parameters, calculations and model used in risk Benzene chosen for fate and transport model. <br /> assessments, and fate and transport modeling; <br /> a15.Rationale why conditions remaining at site will not adversely Contaminants were not detected below fit, which is <br /> impact water quality, health, or other beneficial uses,and sandy soil. TPHg and BTEX were ND. Ground water at <br /> 89 to 110' bgs was not impacted. <br /> NA 16.WET or TCLP results <br /> By: Comments: Vapor extraction was used to reduce contaminant levels in the soil. Results of 1999 MW-1 installation <br /> j show low levels of MtBE and TAME limited to the vicinity of the former tanks site and dont extend to ground water. <br /> EleTPHg and BTEX were nondetect in soil and groundwater samples. Vicinity map shows four wells over one-half mile <br /> 9 from the site. Based on the information provided, we concur with San Joaquin County's closure recommendation. <br />