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1 ' Mr Harlin Knoll 22 May 1998 Page 3 remove the USTs Erickson, Inc , of Richmond, California, was responsible for the transport and disposal of the USTs, tank contents, and ' tank rinsate. The UST removals and subsequent soil and ground water removal and sampling activities were observed by a County representative All work proceeded in accordance with County guidelines and the UST Removal Workplan (ERM 1998) Prior to UST removal, the surface pavements were sawcut and removed ' at each UST site as necessary to remove the tanks An 8-inch thick concrete transformer pad located above UST #2 was also removed Soils above the tanks were excavated as required to expose the top of each ' tank The contents of UST #1 (residual fuel and ground water) were removed from the tank and stored for subsequent transportation and disposal off-site The top of UST #2 was severely deteriorated and was cut open to expose and facilitate removal of the cement slurry inside Under County supervision, soils adjacent to the tank were then 10 excavated to facilitate tank removal All soils removed from the excavations were placed on and covered with 10 mil plastic sheeting for subsequent disposal off-site Under the supervision of City of Tracy Fire Department (CTFD) and County representatives, the USTs were removed from the excavations UST #1 contained holes in the bottom and side of the tank As stated above, UST #2 was severely deteriorated and broke apart during excavation The capacity of UST #1 was approximately 500 gallons and the capacity of UST #2 was approximately 2,000 gallons Dry ice was placed in UST #1 to displace flammable vapors from the tank UST #2 ' was crushed on-site to facilitate transport The USTs were loaded onto trucks and hauled to Erickson's certified disposal facility for disposal ' Copies of the hazardous waste manifests and tank destruction certification for each tank are included in Attachment 1 ' The sidewalls of the UST #1 excavation contained visible hydrocarbon staining and a strong hydrocarbon odor was observed at this location A sheen was also observed on the ground water in the excavation The ' sidewalls of the UST #2 excavation had visible hydrocarbon staining and a slight odor A sheen was also observed on the ground water in the Sexcavation Ground water was at a depth of approximately 7 feet below ' ground surface (bgs) in each excavation ' Based on the visual observations, each tank pit was overexcavated three feet laterally in all directions to remove the most heavily impacted soils