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<br /> LE 1 -CHECKLIST OF REQUIRED DATA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Fire Engine Company#2, 110 Sonora St.W., Stockton, San Joaquin County (Lustis Case#390115)
<br /> y 1. Distance to production wells for municipal, domestic, agriculture, Mormon Slough is located 150 south-southwest.
<br /> industry and other uses within 2000 feet of the site; of the site. There are no drinking water wells
<br /> within 2,500 feet of the site.
<br /> Y Site maps, to scale, of area impacted showing locations of any former One 1,000-gallon gasoline UST(#1) was
<br /> and existing tank systems, excavation contours and sample locations, removed 4/87;one 1000-gallon gasoline UST
<br /> boring and monitoring well elevation contours, gradients, and nearby (#6)was removed 8/87,one 350-galbn waste oil
<br /> surface waters, buildings, streets, and subsurface utilities; UST(94) was removed 4/92;and one 1,000-
<br /> gallon gasoline(#2), and two 550-gallon diesel
<br /> =investia-0-4
<br /> ere removed 10/93.
<br /> Y 3. Figures depicting lithology(cross section), treatment system diagrams; alogy consists of silt, sand, and
<br /> o 65 feet, the total depth (I
<br /> .
<br /> 16.
<br /> ,4. Stockpiled soil remaining on-site or off-site disposal(quantity); The volume and fate of the soil removed was not �
<br /> provided in the reports or.file.
<br /> Y5. Monitoring wells remaining on-site, fate;;, Eight monitoring wells(MW-1 through MW-8), one extraction well(RW-1),
<br /> OZ-
<br /> one piezometer(PZ-1), three air/ozone sparge wells (IAS-1 to 1A5-2,and-1);-and seven soil vapor extraction.-wells(VW-1 to VKA-7)remaining on-site'-
<br /> l will be properly abandoned.
<br /> Tabulated results of all groundwater Depth to groundwater varied from 20 to 45 feet below ground surface(bgs). The y
<br /> elevations and depths to water; groundwater downgradient direction was reported to vary from East to Northeast.
<br /> 7. Tabulated results of all sampling and In 4/87, maximum soil concentrations were: TPHg, 3,300 mg/kg; TPHd, 4,900 }
<br /> analyses: mg/kg;benzene, 54 mg/L; toluene, 280 mg/L;ethylbenzene, 70 mg/kg;and
<br /> t; Y xylenes, 420 mg/L. 1n 6/06 soil confirmation sample results were: TPHg,220
<br /> Detection limits for confirmation mg/kg; benzene, 0.084 mg/kg; toluene, 0.044 mg/kg; ethylbenzene, 1.0 mg/kg;and
<br /> L sampling xylenes, 5.6 mg/kg. Maximum groundwater monitoring concentrations in 12/88
<br /> were: TPHg, 33,700 ug/L; TPHd, 1,900 ug/L;benzene, 4,600 ug/L';toluene,3,840
<br /> �N Lead analyses ug/L;ethylbenzene, 870 ug/L;xylenes, 2,480 ug/L;and MtBE, 250 pg/L. in 7106,
<br /> maximum groundwater monitoring concentrations were: TPHg, 190 ug/L,
<br /> ethylbenzene, 7.5 ug/4;and xylenes, 6.9 u /L.
<br /> LyJ 8. Concentration contours of contaminants found and those remaining in soil and The extent of contamination is,
<br /> roundwater, and both on-site and off-site: adequately defined by soil borings
<br /> Y Lateral and Y Vertical extent of soil contamination and monitoring wells.
<br /> Lateral and B Vertical extent of groundwater contamination
<br /> 9. Zone of influence calculated and assumptions used for subsurface remediation Soil vapor extraction, air sparging,
<br /> system and the zone of capture attained for the soil and groundwater remediation and ozone injection were the
<br /> system; required remedial actions.
<br /> 10.Reports/information QY Unauthorized Release Form [Y QMRs(45 from 1988-2006)
<br /> �y
<br /> Welland boring logs �y PAR My FRP 0 Other,,Site Closure Report
<br /> Y 11.Best Available Technology(BAT) used bran explanation for not using BAT; BAT was soil removal, SVE/AS and ozone
<br /> injection.
<br /> N 12.Reasons why background was/is unattainable using BAT, Minimal soil contamination and groundwater pollution
<br /> remain on-site.
<br /> N 13.Mass balance calculation of substance treated versus that No mass calculations done, however, it appears that
<br /> minimaly etroleum hydrocarbons mass remains.
<br /> remaining-
<br /> 14, Assumptions, parameters, calculations and model used in A risk assessment was not required. Soil E'SLs are not
<br /> risk assessments, and fate and transport modeling; exceeded. Water Quality Goals are exceeded for TPHg.
<br /> Y15. Rationale why conditions remaining at site will not adversely Soil contamination was limited in extent and residual
<br /> impact water quality, health, or other beneficial uses;and contamination will continue to decline. 'Results of 45
<br /> quarters of groundwater monitoring showed a
<br /> Ir
<br /> decreasina trend in concentrations.
<br /> 4 By: JLB49
<br /> � Comments: One 1,000-gallon gasoline UST(#1) was removed 4/87;one 1000-gallon gasoline UST(96) was
<br /> removed 8/87; one 350-gallon waste oil UST(#4) was removed 4/92;and one 1,000-gallon gasoline(#2), and
<br /> Date: two 550-gallon diesel(#3 and#5) were removed 10/93. The SJCEHD closed USTs#4, 5, and 6 in 6/94 without
<br /> 4/10/2007 Regional Board concurrence. Minimal soil contamination and groundwater pollution remain on-site. Based
<br /> upon 45 quarters of declining groundwater concentrations, soil gas not exceeding Region 2 ESLs, and
<br /> minimal contamination present in soil, Regional Board staff concur with San Joaquin County's Closure
<br /> Recommendation.
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