SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

TABU - CHECKLIST OF REQUIRED D�WA •° FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES Site Name and Location: Tuleburg Yacht Harbor, 333 Tuleburg Leyee, Stockton, San Joaquin County ; A well survey was not completed. County states that � 1. Distance to production wells for municipal, domestic, agriculture, no water supply wells were identified within 2,000 feet industry and other uses within 2000 feet of the site; of the site. 2. Site maps, to scale, of area impacted showing locations of former and existing tank systems, Three USTs closed in place. excavation contours and sample locations, boring and monitoring we!1 elevation contours, Site maps are provided. gradients,and nearby surface waters, buildings, streets, and subsurface utilities; cross section treatments stem diagrams; Soil borings show silty clay to 14 feet,and sandy Y� 3. Figures depicting lithology( ) y silt to 20 feet 'r USTs were closed in place. Soils were not excavated. 4. Stockpiled soil remaining on-site or off-site disposal(quantity); Monitoring wells were not installed at this site. —.5._Monitoring,wells remain.ing an-site,.fate;, N 6. Tabulated results of all groundwater elevations and depths to water; Depth to water was measured at 10 to 14 feet bgs. Groundwater flow is estimated to the south. Y 7.Tabulated results of all sampling and analyses:` A"groundwater grab sample collected in January 2000 showed TPHd at 110 pg/1. All other constituents including M#BE were nori-detect: Detection limits for confirmation sampling Maximum soil contamination in mg/kg shows TPHg at 1.4, TPHd at 8.6, l Lead analyses xylenes at 0.016, and lead at 14. All other constituents are non-detect. 8. Concentration contours of contaminants found and those remaining in soil Lateral and vertical extent of soil 0 and groundwater, and both on-site and off-site: contamination is defined. Lateral extent.of Lateral and YLJ Vertical extent of soil contamination groundwater is defined by downgradient © ❑ Lateral and Y� Vertical extent of groundwater contamination City of Stockton monitoring well. Y " 9. Zone of influence calculated and assumptions used for subsurface A remediation system was not operated at 0 remediation system and the zone of capture attained for the soil and d this site. groundwater remediation system; F 10.Reports/information Y� Unauthorized Release Form QN1R$ r 0 Boring logs PAR 0 FRPOther(Subsurface investigation Report) 11.Best Available Technology(BAT) used or an explanation for not using BAT, Natural attenuation of petroleum hydrocarbons. r-- M,12.Reasons why background wasfis TPHd and TPHg remain in on-site soil and groundwater, unattainable using BAT; } 13.Mass balance calculation of substance A mass balance was not completed treated versus that remaining; 14.Assumptions, parameters, calculations and model used in risk A risk assessment was not completed. assessments, and fate and transport modeling, Y 15. Rationale why conditions remaining at site will not adversely Soil and groundwater contamination is limited-in extent. impact water quality, health, or other beneficial uses;and Contamination will naturally attenuate. By: Comments: Three 5,000-gallon USTs(one gasoline and two diesel) were closed-in-place in May 2000. Soil samples P � collected from six soil borings showed maximum concentrations of TPHg and TPHd at 1.4 mg/kg and 8.6 mg/kg, respectively. One groundwater grab sample, collected at 14.5 feet bgs in soil boring SB-1, showed TPHd at 110 pg/!. No other constituents including MtBE were detected. The City of Stockton monitoring well MW-8 at the former Union Oil Date: Company property, 130 feet south and downgradient of,the site showed toluene at 0.93 pg/1 in September 1999. All other constituents tested were non-detect. The closed-in-place USTs are approximately 255 feet south of the Stockton Channel. The groundwater flow direction is consistently to the south as identified at multiple south shore sites. The area south of the site is covered with asphalt`which should limit leaching and transport of contaminants. Based on the limited t, extent of soil and groundwater contamination, Board staff concur with San Joaquin County's closure recommendation.