SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

- NMI," not appear that any refined products intended for distribution to commercial accounts were ever stored at the Unocal site. The two underground tanks at the Unocal site were subsequently removed in 1992 . The subject facility was also previously used to store bulk lube oil products (in drums) intended for distribution to commercial accounts. The bulk lube oil products were reportedly stored in the warehouse portion of the existing building. However, in order to respond to competitive market factors necessitating the need for additional bulk oil capacity at the site, two 10, 000 gallon above ground tanks were installed at the site in 1988-1989. A concrete secondary containment berm surrounding the aboveground tanks was also installed at that time. The aboveground storage tanks and secondary containment berm have subsequently been removed from the site. There was one other potentially pertinent activity conducted at the subject site. In approximately 1979, Unocal subleased the northeast portion or the subject site to Standard Transmission (ST) Services. ST installed a vapor recovery unit (apparently also including an underground storage tank) on this part of the site. The vapor recovery unit is still present at the site. No other records pertaining to ST's use of the property were present in the Unocal files. It is important to note that the subject site is located adjacent to several facilities that individually and collectively store and distribute millions of gallons of petroleum products. It is also pertinent to point out that at least two of these facilities (the Arco Terminal and ST Services facilities) have experienced large-scale releases of petroleum products. As outlined in this letter, the petroleum product storage activities previously conducted at the Unocal site were minimal in comparison to the activities that were and are being performed at the adjacent facilities. It is known that the soil and groundwater surrounding the former Unocal site has been significantly impacted by hydrocarbon contamination resulting from releases by nearby facilities. However, relatively minimal amounts of hydrocarbon contamination have been detected at the Unocal site in the proximity of the former Unocal site improvements. Based on this fact, and based on the fact that the magnitude of the scope of Unocal's former operations is significantly less than those of others in the vicinity, it is our technical opinion that no further site investigation, remediation, or monitoring work is warranted at the Unocal site. It is Unocal's intention to request formal closure from the San Joaquin County Public Health Services once your assessment is complete. A letter documenting your conclusions concerning Unocal's future involvement in remediating the former bulk plant site would be greatly appreciated.