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.dl TABLV1 - CHECKLIST OF REQUIRED DVA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Cal Trans Lodi Maintenance Station, 845 Pine Street, Lodi, San Joaquin County
<br /> 0 I. Distance to production wells for municipal, domestic, agriculture, Groundwater contamination was not Identified,and a
<br /> industry;and other uses within 2000 feet of the site, well receptor survey was not required. As shown in
<br /> GeoTracker,no wells are located within 2,400 feet.
<br /> F Two USTs were removed
<br /> Y 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems, in 11/89. Site maps are
<br /> excavation contours and sample locations, boring and monitoring well elevation contours,
<br /> gradients, and nearby surface waters, buildings, streets, and subsurface utilities; provided in the 9/95 Site
<br /> Assessment Report.
<br /> T] 3. Figures depicting lithology(cross section), treatment system diagrams, Lith ology consists of sand and sand/slit
<br /> mixtures to 100 feet the total depth
<br /> investigated. i
<br /> 4. Stockpiled soil disposed off site(quantity); The disposition of excavated soli was not presented. The soils were
<br /> likely returned to the tank pit excavations.
<br /> N 5. Monitoring wells remaining on-site, fate; Groundwater contamination was not identified,and monitoring wells were
<br /> not installed.
<br /> N 6. Tabulated results of all groundwater elevations and depths to water,•�The dep��to grounafwater was first identifled at
<br /> 76 feet in a CPT boring.
<br /> 0 7. Tabulated results of all sampling and analyses: Maximum concentration of soli contamination shows TPHg at
<br /> Detection limits for confirmation sampling 1,500 mg/kg,and total BTEX at 419 mg/kg. Two groundwater grab
<br /> samples collected at 76 and 87 feet were non-detect for all
<br /> 0 Lead analyses constituents. Due to USTs being used for unleaded fuel and diesel
<br /> only,an-analysis for lead was not required.
<br /> y� 8. Concentration contours of contaminants found and those remaining in soil Soil samples collected during the
<br /> and groundwater, both on-site and off-site: Investigation activities showed limited
<br /> Lateral and 0 Vertical extent of soil contamination contamination to a maximum depth of
<br /> 11 feet. Two groundwater grab samples
<br /> Latelal and fI Vertical extent of groundwater contamination were non-detect for all constituents.
<br /> 9.Zone of influence calculated and assumptions used for subsurface Based on minor soil contamination at the
<br /> N remediation system and the zone of capture attained for the soil and former UST and dispenser areas,site
<br /> groundwater remediation system, remediation was not required.
<br /> FE 10.Reports/information Unauthorized Release Form QMRs
<br /> Ifl Boring logs N❑ PAR El FRP Site Assessment Report, 9/95;Investigation Report, 4/02
<br /> a11.Best Available Technology(BAT)used or an explanation for not using BAT,' The USTs, dispensers, and associated
<br /> piping were removed.
<br /> Y 12.Reasons why background warms Minor contamination remains In soil at the former UST and dispenser areas.
<br /> unattainable using BAT, - - :This_contamination_does not present a.significant threat to groundwater.
<br /> 13.Mass balance calculation of substance Based on the limited soil contamination identified at the former UST areas, a
<br /> treated versus that remaining; mass balance was not required. +
<br /> 14.Assumptions,parameters, calculations and model used in risk Based on the limited soil contamination identified at the
<br /> assessments, and fate and transport modeling; former UST areas, a risk assessment was not required.
<br /> {
<br /> Y 15. Rationale why conditions remaining at site will not adversely Minor contamination remains in soil at the subject site.
<br /> impact water qualify, health, or other beneficial uses. The remaining contamination Is limited in extent and
<br /> does not present a significant threat to groundwater.
<br /> By: Comments: The site is a Cal Trans Maintenance Station in Lodi. In November 1989, two USTs(one 1,000-gallon
<br /> 1E urileaded gasoline and one 1,000-gallon diesel)were removed from the subject site. No soil samples were collected at the
<br /> time of the UST removal due to a concrete slab under the USTs. In May 1990, soil samples were collected under the
<br /> concrete slab at approximately 11 feet, and TPHg and BTEX constituents were identified of a maximum concentration of
<br /> Date: 1,500 mg/kg and 419 mg/kg, respectively. In August 1995, eight borings were completed to a total depth of 46 feet, and
<br /> 6/11102 the limit of soil contamination was confirmed to a maximum depth of 11 feet. In February 2002, one CPT boring was
<br /> completed to a maximum depth of 100 feet;and two wafer samples were collected at 76 and 87 feet. Both water samples
<br /> were analyzed for volatile organic compounds and fuel oxygenates by EPA Method 8260B, and were non-detect for all
<br /> constituents including MtBE at acceptable defection limits. Based on the limited soil contamination remaining at this site
<br /> acid the lack of groundwater impacts, Board staff concur with San Joaquin County's closure recommendation.
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