|
TABLY1 - CHECKLIST OF REQUIRED DATA
<br /> f FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Port of Stockton (Site 5), Port Road 21 and M, Stockton, San Joaquin County
<br /> ❑ 1. Distance to production wells for municipal, domestic, agriculture, Well survey completed in September 4999. The
<br /> industry and other uses within 2000 feet of the site; nearest water supply well is 1,000 feet south. No
<br /> drinking water wells within 2,000 feet of the site.
<br /> Y
<br /> 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems, Four 12,000-gallon gasoline
<br /> USTs removed in May 1989.
<br /> excavation contours and sample locations, boring and monitoring well elevation contours,
<br /> gradients, and nearby surface waters, buildings, streets, and subsurface utilities,
<br /> 0 3. Figures depicting lithology(cross section), treatment system diagrams; Borehole lithology and cross section figures
<br /> show'predominantly silty sands and clay.
<br /> ❑y 4. Stockpiled soil remaining on-site or off-site disposal(quantity); approximately 50 cubic yards of excavated soil was
<br /> stockpiled,sampled, found to be nondetect and
<br /> returned to the excavation.
<br /> 0 5. Monitoring wells remaining on-site, fate; Three monitoring wells currently exist on-site. The monitoring wells will be
<br /> destroyed pending site closure.
<br />•, --�_.��.�: ,..�. r � ,�_,. ,� _ =.�----may:. ---- _._.� .. _ ,. _,.� . � _ �—_ .
<br /> Q6. Tabulated results of all groundwater elevations and depths to water, Depth to water Is approximately six feet bgs, and .E
<br /> flow is to the southeast
<br /> 7. Tabulated results of al!sampling and analyses: October 1999 groundwater results in pg/I show ND for all constituents
<br /> (TPHg at<50,MtBE<0.5,all BTEX compounds at<0.5). MtBE has not
<br /> Detection limits for confirmation sampling been identified at this site. Total lead was<0.1 mg/1 from groundwater
<br /> Lead analyses grab samples completed in August 1998.
<br /> y� 8. Concentration contours of contaminants found and those remaining in soil Lateral and vertical extent of soil and
<br /> and groundwater, and both on-site and off-site: groundwater contamination defined.
<br /> ElLateral and 171 Vertical extent of soil contamination
<br /> Lateral and Vertical extent of groundwater contamination
<br /> y❑ El
<br /> f0 9_zone of influence calculated and assumptions used for subsurface A remediation system was not operated at
<br /> remediation system and the zone of capture attained for the soil and this site.
<br /> groundwater remediation system;
<br /> EE10.Reports/information Y❑ Unauthorized Release Form l QMRs(7/99, and 10/99)
<br /> Welland boring logs HIPAR ❑ FRP Other
<br /> 11.Best Available Technology(BAT) used or an explanation for not using BA T, Remove UST and contaminated soils,
<br /> natural attenuation.
<br /> 12fReas6ns why background ivaslrs
<br /> unattainable using BAT Low concentrations of TPHg and BTEX exist in site soils.
<br /> 13.Mass balance calculation of substance Only minor detections of TPHg and BTEX constituents were identified in site
<br /> 0 treated versus that remaining; soils. Amass balance calculation was not completed.
<br /> ❑N 14.Assumptions,parameters, calculations and model used in risk A risk assessment was not completed_
<br /> assessments and fate and transport modelin
<br /> � P g,
<br /> 15. Rationale why conditions remaining at site will not adversely Groundwater monitoring has demonstrated that the
<br /> yJ impact wafer quality, health, or other beneficial uses;and groundwater is not Impacted. Remaining soil
<br /> contamination will naturally degrade.
<br /> NA 16.WET or TCLP results
<br /> gy; Comments: Four, 12,000-gallon US Ts were removed in May 1989. Low concentrations of TPHg and BTEX were
<br /> identified in on-site soils during UST removal and site investigation activities. MtBE has not been identified at this site.
<br /> Groundwater monitoring for two consecutive quarters show no groundwater impacts. The nearest water supply well is
<br /> Date: approximately 1,000 feet south of the site. Based on information provided by the County, Board staff concurs with the
<br /> Y/7.8 ca County's closure recommendation.
<br />
|