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TAB E 1 - CHECKLIST OF REQUIRED DTA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Safeway Meat Processing Plant, 1111 Navy Drive,Stockton, San Joaquin County
<br /> 1. Distance to production wells for municipal, domestic, agriculture, An updated well survey in 1998 shows the nearest
<br /> industry and other uses within 2000 feet of the site; water supply well is approximately 1320 feet to the
<br /> east and downgradient of the site. This well has been
<br /> out of service since 1978.
<br /> Y� 2. Site maps, to scale, of area impacted showing locations of former and existing tank Four USTs(12,000-gallon
<br /> systems, excavation contours and sample locations, boring and monitoring well elevation diesel)were removed in July
<br /> contours, gradients,and nearby surface waters, buildings, streets, and subsurface utilities; 1987.
<br /> 0 3. Figures depicting lithology(cross section), treatment system diagrams; Site lithology consists of silt and clay to 50 feet,
<br /> the total depth investigated, with a high
<br /> permeability zone between 20 and 30 feet.
<br /> 4. Stockpiled soil disposed off-site(quantity); Excavated soil was redistributed at the site after aeration.
<br /> F 71 5. Monitoring wells remaining on-site, fate; Six monitoring wells have been installed for this investigation. Three wells
<br /> (MW-1,MW-2,and MW-3)were destroyed in 1991. The remaining three wells
<br /> (MW-4,MW-S,and MW--6)will be-properly destroyed pending site closure.
<br /> 0 6. Tabulated results of all groundwater elevations and depths to water, The depth to water varied from 9 to 30 feet,and the
<br /> groundwater flow direction varied from east to
<br /> southeast.
<br /> Q7.Tabulated results of all sampling and analyses: Groundwater monitoring results for three monitoring wells(MW-1 to
<br /> MW-3)were non-detect for BTEX and TPHd from 8/87 to 11/91.
<br /> Y Detection limits for confirmation sampling Maximum groundwater monitoring results for monitoring wells MW-4.
<br /> Lead analyses MW-5,and MW-6 were 290 Yg/L for TPHd from 4/02 to 7/02.
<br /> ETJ 8. Concentration contours of contaminants found and those remaining in soil
<br /> and groundwater, both on-site and off-site: The extent of contamination is defined by
<br /> ®Y Lateral and Y Vertical extent of soil contamination on-site soil borings and monitoring wells.
<br /> Lateral and ® Vertical extent of groundwater contamination
<br /> Q9. Zone of influence calculated and assumptions used for subsurface Based on the limited extent of soil
<br /> remediation system and the zone of capture attained for the soil and contamination,an engineered remediation
<br /> groundwater remediation system; system was not warranted at this site.
<br /> 0 10.Reports/information Y❑ Unauthorized Release Form QMRs(2/92 to 3/95,4/02 to 7/02)
<br /> Y❑ Boring logs N❑ PAR N❑ FRP (Site Closure Report, 8/98)
<br /> FE 11.Best Available Technology(BAT)used or an explanation for not using BAT,• Remove USTs,natural attenuation.
<br /> 0 12.Reasons why background was/is Background groundwater concentrations have been attained at all monitoring
<br /> unattainable using BAT, wells. Minor soil contamination remains on-site in the former diesel UST area.
<br /> The 1998 Site Closure Report identified rive upgradient sites potentially
<br /> contributing petroleum hydrocarbon contamination to the site.
<br /> ED13.Mass balance calculation of substance The consultant estimates that 1,411 pounds of TPHd remains in shallow soils
<br /> treated versus that remaining, in the area of the former diesel UST area. The consultant estimates that 26.5
<br /> gallons of TPHd remain in groundwater in the area of the former diesel UST
<br /> area.
<br /> Nq 14.Assumptions,parameters, calculations and model used in risk A risk assessment was not required.
<br /> assessments, and fate and transport modeling;and
<br /> 15. Rationale why conditions remaining at site will not adversely Soil contamination is limited in extent,and based on the
<br /> impact water quality,health,or other beneficial uses. last two sampling events,contamination is not
<br /> continuing to leach to groundwater. Groundwater
<br /> monitoring shows a decreasing trend in diesel
<br /> concentrations.
<br /> By: Comments: Four USTs(12,000-gallon diesel) were removed from the subject site in July 1987. Soil contamination was
<br /> JLB identified at the diesel UST area, and multiple borings and six monitoring wells were completed to delineate and monitor
<br /> contamination at this site. Groundwater grab samples from borings in 1995 showed upgradient TPHd concentrations at
<br /> Date: 420 Ng/l and downgradient TPHd concentrations at 1,100 pg/l. Monitoring wells MW-5 and MW-6,installed downgradient
<br /> of the former diesel tanks pit, were sampled from 2/92 to 3/95 and from 4/02 to 7/02. TPHd was identified in MW-5(900
<br /> 1/7/03 Ng/1)and MW-6(1,200 Ng/I)in 2/92. For the last two sampling events, groundwater from monitoring wells MW-4 and MW-
<br /> 6 have been non-detect for all constituents, while groundwater samples from MW-5 varied from non-detect to 290 pg/l.
<br /> Based on the limited extent of soil contamination and decreasing TPHd concentrations in groundwater, Board staff concur
<br /> with San Joaquin County's Closure Recommendation.
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