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<br /> TABLE- CHECKLIST PF REQUIRED.DA'
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
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<br /> Site Name and Location: City of Lodi Safety Blvd.,230 Elm Street, Lodi,San Joaquin County
<br /> ED 1. Distance to production wells for municipal, domestic,agriculture, A well survey In 2001 shows two public water supply
<br /> Industry and other uses within 2000 feet of the site; wells located approximately 1500 feet north and 2000
<br /> feet southwest of the site. .,
<br /> Q2. Site maps, to scale, of area impacted showing locations of former and existing tank One 10,000-gallon gallon diesel j
<br /> systems, excavation contours and sample locations, boring and monitoring well UST was removed In 9/87. A.2,000- 1
<br /> elevation contours, gradients,and nearby surface waters, buildings, streets,and gallon diesel UST was Installed In
<br /> subsurface utilities; 8/88,removed In 10/88, and re-
<br /> Installed In 12/88. One 18,400-
<br /> gallon gasoline UST was grouted
<br /> In place In 12/98.
<br /> 0 3.Figures depicting lithology(cross section), treatment system diagrams; Site Iithology consists of silt and sand to 59 fee4
<br /> the total depth Investigated.
<br /> 4. Stockpiled soil disposed off-site(quantity); Approximately 42 cubic yards of excavated soil and gravel was
<br /> transported by the City of Lodi to another City facility for disposal.
<br /> investigation. The wells will be properly destroys been installed for this _
<br /> 3.^Monitorin we11s-reinainm on=site,-Yate;- Tivo_.monitorin_g_we//s(MW-.1 through MW 2))have s
<br /> 0 g g d pending site olos'ure.'"
<br /> 6. Tabulated results of all groundwater elevations and depths to water The depth to water varied from 45 feet(1978)to 35
<br /> feet(1998),and the regional groundwater flow
<br /> direction is to the south and southwest
<br /> �Y 7.Tabulated results of all sampling and analyses: All soll results were ND In 9/87. In 10/88,soil results were 1,200 mg/kg
<br /> Y Detection limits for confirmation sampling for TPHd and 0.49 mg/kg for xylenes. After over-excavation and
<br /> reinstalling the replacement tank in 12/88,all soli results were ND.
<br /> Lead analyses Groundwater monitoring results were ND for TPHd,,TPHg,and BTEX
<br /> from 10186(o 10/95. In 6/98,groundwater monitoring results were ND
<br /> for TPHd, TPHg,BTEX,and MTBE.
<br /> 8. Concentration contours of contaminants found and those remaining in soil
<br /> d groundwater, both on and off-site: The extent of contamination 1s defined by
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<br /> ® Lateral and LLLII! Vertical extent of soil contamination on-site soil borings and monitoring wells.
<br /> Lateral and Vertical extent of groundwater contamination .
<br /> 0 9. Zone of influence calculated and assumptions used for subsurface
<br /> remediation system and the zone of capture attained for the soil and Based on the limited extent of soil
<br /> groundwater remediation system; contamination,an engineered remediation
<br /> system was not required at this site. f
<br /> Q 10.Reports/information ITI Unauthorized Release Form QMRs 10/86, 3/88, 6/88, 10/95, and 3/98.
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<br /> Y❑ Boring logs El PAR El FRP Other Soil Analysis Laboratory Report 12/88.
<br /> 0 11.Best Available Technology(BAT)used or an explant on for not using BAT,, Remove/grout in place USTs and natural
<br /> attenuation.
<br /> 12.Reasons why background wasrs
<br /> unattainable using BA
<br /> Groundwater contamination was not found during monitoring.No soil "
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<br /> contamination remains on-site.
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<br /> Y� 13.Mess balance calculation , substance
<br /> treated versus that remaining; .,Since no contamination remains onsite,mass balance was not required for soil
<br /> or groundwater.
<br /> 14.Assumptions,parameters, calculations and model used in risk A risk assessment was not required.
<br /> assessments,and fate and transport modeling;and
<br /> E15. Rationale why conditions remaining at site will not adversely Sof/contamination is not presen4 and based on rive h
<br /> impact water quality, health, or other beneficial uses. groundwater sampling events over fen years,
<br /> contamination has not leached to groundwater.
<br /> By: . Comments: One 10,000-gallon diesel UST was removed from the subject site in 9/87. One 18,400-gallon gasoline UST
<br /> n,B was closed in place by grouting in 12/98. A new 2,000-gallon diesel UST was installed in 8188,removed in 10/88, and
<br /> reinstalled in 12/88, due to a failed precision test. Soil results at the east end of the failed 2,000-gallon tank were 1,200 i
<br /> Date: mg/kg for TPHd and 0.49 mg/kg for xylenes. Aker re-excavation to 16 feet depth, confirmation soil samples were ND for
<br /> TPHd and BTEX. Two borings and two monitoring wells were completed in 10186 to determine if soil and groundwater
<br /> contamination existed at the gasoline UST. Groundwater analyzed from UST monitoring wells MW-1 and MW-2 reported
<br /> 5/22/03 ND for BTEX, TPHg, and TPHd from 10/86 to 10/95. In 6/96, TPHd, TPHg,BTEX, and MTBE groundwater results were
<br /> ND. Based on the removal of all soil contamination and no contamination present in groundwater, Regional Board staff I
<br /> concur with San Joaauin Countv's Closure Recommendation.
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