SITE INFORMATION AND CORRESPONDENCE_FILE 1

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Mr. Edward C. Ralston Unocal Corporation August 24, 1995 Page 3 September 18, 1995. If field work can commence September 18, 1995, Delta anticipates that the work proposed in the August 18, 1995, work plan can be completed in three to four days, depending on the number of additional Geoprobe borings. Following completion of the field work, Delta anticipates submitting the report of findings within 30 days of completing the field work. Based on the results of the investigation, assessment/remedial options and the time to implement these options will be assessed. Method of Disposal Pea-gravel, soil, and sluff material removed from the former product piping trenches, dispenser areas, and canopy pits was stockpiled on-site and sampled. Following sampling, the soil was transported via Manley & Sons Trucking, Inc. of Sacramento California to Forward Landfill in Stockton, California. Soil was stockpiled at Forward Landfill pending receipt of the analytical results prior to disposal. It is Delta's understanding that the soil remains at Forward Landfill pending disposal at the authority and direction of the SJCPHS-EHD. Proposed Methods of Replacement of Containment During the construction of the new service station, new piping and dispensers will be installed at the site. A secondary containment system consisting of a Bravo containment box is proposed to be installed beneath each dispenser. Product piping connected to the dispensers will be double-walled fiberglass and will connect to a new sump box placed around the turbins of each tank. If a leak appears within the inner product line, product will travel between the two lines back to the sump box. A sensor will be placed within the sump and is connected to a Veeder-Root TLS 350 monitor within the station building. If product enters the sump, the alarm will be triggered. New electronic tank gauges will also be placed in each tank. These gauges will be connected to the alarm system. During times of non-pumping, the gauges will measure slight changes in the tank level. If a decrease is observed, the alarm will be triggered. In addition, each tank will also be retrofitted with overfill and spill containment boxes around both the fill and venting ports of each tank. Additional Actions to Prevent Releases Unocal is installing secondary containment and alarm systems on the tanks, dispensers, and lines. Details of the proposed installation are presented in the previous section. Remarks/Signatures The interpretations contained in this report represent our professional opinions,and are based in part, on information supplied by the client and the analyzing laboratory. These opinions are based on currently available information and are arrived at in accordance with currently accepted hydrogeologic and engineering practices at this time and location. Other than this, no warranty is implied or intended.