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<br /> ,v.o'ABLE 1 -CHECKLIST OF REQUIRED DATA -*
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Manteca Equipment Rental,616 South Main Street, Manteca, San Joaquin County
<br /> 1. Distance to production wells for municipal, domestic, agriculture, industry This is a soil case. Groundwater was not
<br /> and other uses within 2000 feet of the site; impacted from the UST release.
<br /> 2. Site maps, to scale,of area impacted showing locations of former and existing tank systems, In December 1990,two Lists
<br /> excavation co.Ontours and sample locations,boring and monitoring well elevation contours, (one and one
<br /> 500-gallon
<br /> ltan gaass dieseloline)were
<br /> gradients, and nearby surface waters, buildings, streets, and subsurface utilities, removed from the site.
<br /> Y� 3. Figures depicting lithology(cross section), treatment system diagrams, No treatment system was used.
<br /> 0 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Excavated soil was returned to the former tank pit
<br /> NA 5. Monitoring wells remaining on-site, fate; No monitoring wells were installed at the site.
<br /> NA 6. Tabulated results of all groundwater elevations and depths to water,. Groundwater elevations are estimated between 15 and 30
<br /> feet bgs,with a northwesterly flow direction.
<br /> FY 1 7. Tabulated results of all sampling and analyses: TPHd at 280 mg/kg, TPHg at 19 mg/kg,and minor TEX were detected in soil
<br /> samples from beneath the USTs. During the 1999 site investigation,
<br /> Y Detection limits for.confrrmation sampling contaminants,including MtBE, were not detected above detectable limits in the
<br /> Lead analyses soil samples. Groundwater was not encountered during the investigation.
<br /> 8. Concentration contours of contaminants found and those remaining in soil
<br /> and groundwater, and both on-site and off-site:
<br /> F9Lateral and 19 Vertical extent of soil contamination
<br /> FN-A-1Lateral and NA Vertical extent of groundwater contamination
<br /> FN_A__1 9.Zone of influence calculated and assumptions used for subsurface No subsurface remediation system was used at
<br /> remediation system and the zone of capture attained for the soil and the site.
<br /> groundwater remediation system;
<br /> 0 10.Reports/information D Unauthorized Release Form NA MRs(Dates)
<br /> Iq Welland boring logs EIPAR NA FRP 0 Other(report name)July 30, 1999 Investigation Workplan
<br /> Y� 11.Best Available Technology(BAT)used or an explanation for not using BAT,- The leak sources were removed from the site
<br /> Y� 12.Reasons why background wasfis unattainable using BAT, In 1999,contaminants were not detected in the former tank pit
<br /> NA 13.Mass balance calculation of substance treated versus that remaining;
<br /> NA 14.Assumptions,parameters,calculations and model used in risk
<br /> assessments, and fate and transport modeling;
<br /> NA 15.Rationale why conditions remaining at site will not adversely
<br /> impact water quality, health,or other beneficial uses,and
<br /> 16.WET or TCLP results
<br /> By'-1;f
<br /> in 1990,moderate levels of TPHd, TPHg,and TEX were found in soil samples beneath the former tanks.In 1999,one
<br /> �- soil boring was advanced in the central location of the tank site. The sample was analyzed for TPH,BTEX,and MtBE. No
<br /> Date: contaminants were detected in the soil sample. Groundwater was not encountered during the soil boring activity. Based on the
<br /> �O/�/ absence of contamination from the UST release,including MtBE,staff concurs with San Joaquin County's closure recommendation.
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