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TAB* 1 - CHECKLIST OF REQUIRED SA
<br /> FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES
<br /> Site Name and Location: Herman & Helen's Marina, 15135 Eight Mile Road, Stockton, San Joaquin County
<br /> Ell 1. Distance to production wells for municipal, domestic, No water supply wells were identified within 1,000 feet of
<br /> agriculture, industry and other uses within 2000 feet of the site; the site. The nearest surface water body is the Little
<br /> Connection Slough, which is a source of drinking water.
<br /> y 2. Site maps, to scale, of area impacted showing locations of former and existing tank
<br /> systems, excavation contours and sample locations, boring and monitoring well elevation Three USTs were removed in
<br /> contours, gradients, and nearby surface waters, buildings, streets, and subsurface utilities; 1981• Site maps are provided.
<br /> Y� 3. Figures depicting lithology(cross section), treatment system diagrams; Soil borings show silty sands, silty clay and peat
<br /> soils 30 feet.
<br /> a 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Excavated soils were returned to the tank pit
<br /> excavations, or disposed off site.
<br /> 5. Monitoring wells remaining on-site, fate,, Four monitoring wells have been installed. The wells will be retained for
<br /> Y investigation of the suspected AGT release.
<br /> FY 6. Tabulated results of all groundwater elevations and depths to water; Depth to water is 4 to 6 feet bgs, and groundwater
<br /> flow is consistently to the southeast.
<br /> FT7. Tabulated results of all sampling and analyses: The maximum groundwater concentrations in pg/I show TPHg at 3,100;
<br /> BTEX at 70,43, 45, 680, respectively,MtBE at 190,000; TBA at 3,300;
<br /> Detection limits for confirmation sampling and TAME at 1,370. No indication of lead analysis. TPHg and BTEX
<br /> ❑ Lead analyses constituents were identified downgradient of the former USTs. Fuel
<br /> oxygenates were identified downgradient of the AGTs.
<br /> Y 8. Concentration contours of contaminants found and those remaining in soil
<br /> and groundwater, and both on-site and off-site: Lateral and vertical extent of soil and
<br /> Lateral andY❑ Vertical extent of soil contamination groundwater contamination is defined for
<br /> Lateral and Vertical extent of groundwater contamination the former UST. Additional work may be
<br /> y� y❑ needed to define the AGT release.
<br /> 9. Zone of influence calculated and assumptions used for subsurface
<br /> remediation system and the zone of capture attained for the soil and A remediation system was not operated at
<br /> groundwater remediation system; this site.
<br /> Q10.Reports/information 171 Unauthorized Release Form 0 QMRs
<br /> y❑ Boring logs PAR F1 FRP y❑ Other(Soil and Groundwater Investigation Report)
<br /> 11.Best Available Technology(BAT) used or an explanation for not using BAT; UST removal, natural attenuation of
<br /> petroleum hydrocarbons.
<br /> y� 12.Reasons why background waslis
<br /> unattainable using BAT; TPHg and BTEX constituents remain in on-site soil and groundwater.
<br /> 0 N 13.Mass balance calculation of substance
<br /> treated versus that remaining; A mass balance was not completed.
<br /> N 14.Assumptions, parameters, calculations and model used in risk 0 A risk assessment was not completed.assessments, and fate and transport modeling;
<br /> Y 15. Rationale why conditions remaining at site will not adversely Soil and groundwater contamination associated with the
<br /> impact water quality, health, or other beneficial uses. former UST is limited in extent. Site transferred to the
<br /> Regional Water Board Site Cleanup Section for further
<br /> remedial actions.
<br /> gy: Comments: Three USTs(one 1,000, one 3,000, and one 10,000 gallon) were removed in October 1991. Soil
<br /> contamination was identified in the tank pit soils, multiple borings were completed, and four monitoring wells have been
<br /> installed. Groundwater monitoring has been conducted quarterly since September 1997, and TPHg, BTEX, and low MtBE
<br /> (maximum 14 jig/1) was identified in MW-4 directly downgradient of the former US Ts. MtBE(maximum 190,000 pg/I), TBA,
<br /> Date: and TAME have been identified in MW-2 and-3 directly downgradient of the existing AGTs. Based on these results,
<br /> /��// Board staff determined that the UST site should be closed, and the case transferred to the Site Cleanup Section for
<br /> / regulatory oversight of the AGTs.
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