APPENDIX E SCIG Environmental Site Assessments

More documents

Recommendations

Info

Phase I Environmental Site Assessment 16 Southern California International Gateway – Executive Summary Following the removal of the USTs, fuel dispensers and product piping, confirmation soil samples indicated hydrocarbon impacts beneath all four dispenser islands (highest concentrations were beneath dispenser D2 [25,000 mg/kg TPHd] and product piping immediately west of dispenser D2 [20,000 mg/kg TPHd]) and associated product piping from approximately 2 to 12 feet bgs. Soil samples collected beneath the former USTs did not indicate any impacts (maximum concentration; 8.8 mg/kg TPHd). Soil remediation activities took place in impacted areas on two separate occasions; in 1998 for dispensers D3 and D4 and later in 2003 for dispenser D2. Approximately 346 tons and 363 tons and of impacted soils were removed from the site in 1998 and 2003, respectively. Based on the available files at the time of this Phase I ESA, high TPHd remained in soil from confirmation sampling following remedial soil excavation activities in 2003. TPHd concentrations of 60,700 mg/kg, 56,000 mg/kg, and 24,000 mg/kg were reported in three soil samples immediately west of dispenser D3. Shaw Environmental Inc. (Shaw) reported that impacted soils could not be safely removed without jeopardizing the integrity of the UST system. Praxair planned on removing the impacted soils concurrently with dispenser replacement activities. However, no information was provided in the files pertaining to the additional soil removal and/or dispenser upgrade activities. • In 2003, three groundwater monitoring wells (MW-1 through MW-3) were installed at the site for the purposes of assessing any groundwater impacts associated from past releases of petroleum hydrocarbons from the UST system. Laboratory results of groundwater samples showed concentrations of MTBE below California Primary and Secondary Maximum Contaminant Levels (MCLs) of 13 μg/L and 5 μg/L, respectively, and TPHd concentrations below 1 milligram per liter (mg/L). Volatile organic compounds (VOCs) were also detected in each well but at concentrations below MCLs except for 1,1-DCA (43 μg/L) and 1,1-dichloroethene (1,1-DCE; 13 μg/L) in well MW-1 and 1,1-DCA (33 μg/L) and 1,1-DCE (11 μg/L) in well MW-2. Based on the interpreted groundwater flow direction to the northeast, these wells are positioned up- to cross-gradient to the UST and fuel dispensers. The source of the chlorinated solvents has not been identified and is a concern. • Although no “No Further Action Required” letter was found in files obtained from the Los Angeles Regional Water Quality Control Board (LARWQCB), the LUST database listing indicated the LARWQCB environmental case status as “Closed”. It remains unknown if additional impacted soils adjacent to dispenser D3 were removed prior to the site receiving site closure. If soils with residual TPHd concentrations of up to 60,700 mg/kg remain at the site, then such concentrations adversely impact the property and could lead to degradation of the groundwater. Further, groundwater monitoring wells were not located within the presumed source area (area of highest TPHd concentrations), rather, they were located (based on a groundwater flow direction to the northeast, as reported by Shaw in 2003) up- and cross-gradient of the source area. Based on this information, groundwater may be more severely impacted beneath or downgradient (northeast) from the former and current fuel dispensers. Draft Report SCIG Executive Summary.doc The Source Group, Inc.
Phase I Environmental Site Assessment 17 Southern California International Gateway – Executive Summary In addition to the USTs described above, seven additional USTs were listed within the HSTPST and USTFID databases for the Praxair site. The UST listed included: 1. 12,000-gallon, diesel, installed in 1974; 2. 10,000-gallon, diesel, installed in 1967; 3. 5,000-gallon unleaded, installed in 1967; 4. 6,000-gallon, waste (sodium tripolyphosphate, diethtanolamine, dodecylbenzene sulfoinc acid), installed in 1974; 5. 550-gallon, waste oil, installed in 1967; 6. 76,000-gallon, waste (cooling water, phosphates, chlorine), installed 1967; and 7. 5,000-gallon, waste (cooling water, steam boiler blow down water) Although these were listed within the USTFID database, some or all of these tanks could actually be aboveground tanks. It is not known if these tanks currently exist at the site or have been removed. Listings within the HSTPST database report, dated 1988, indicated the tanks were still in use, however, this information may or may not be correct. The issue of these tanks and their existence, especially if they were placed underground, could pose risks to the property. The following provides a summary of information obtained from the site reconnaissance and interview with site personnel. • The cooling towers use several chemicals to treat the water: an antifoam product, sulphuric acid, sodium hypochlorite, and two corrosion inhibitors. • Praxair has many transformers on site. There were multiple transformers with posted statements confirming PCB-containing dielectric fluid. Praxair has oil storage in between the two production units. There are 55-gallon oil drums with proper secondary containment. • On the west side of the plant maintenance building there are two vent stacks coming from underground, and four metal plates that appear to be a former clarifier. Adjacent to the clarifier there appears to be a rectangular patch of ground of different age and coloring then the surrounding surface. Additional assessment would be required to determine if these locations are sites of removed or replaced USTs. Warren E&P, Inc. The area has been used for oil production/exploration since the mid-1930s. Numerous oil wells are located throughout the Site within the oil field known as the Wilmington Unit. Based on the Department of Oil, Gas and Geothermal Resources (DOGGR) map, twenty one (21) oil production or injection wells exists within the site boundaries. Warren E & P has wells across the North Wilmington Unit. The wells are located mainly toward the southern end of the SCIG project area. From site reconnaissance activities, all wells observed appeared in good condition and well maintained by Warren E & P. We were unable to find the abandoned wells, however, the historical and current use of the subject land as an oil field poses risks (RECs) to the properties from petroleum hydrocarbons Draft Report SCIG Executive Summary.doc The Source Group, Inc.
Page 1 and 2: APPENDIX E SCIG Environmental Site
Page 3 and 4: Phase I Environmental Site Assessme
Page 17: Phase I Environmental Site Assessme
Page 29 and 30: Figures
Page 31: Plate 1 Parcel Map for SCIG Project
Page 35 and 36: Table 1 Summary of Recognized Envir

APPENDIX E SCIG Environmental Site Assessments

Create successful ePaper yourself

Delete template?

Save as template?