Orlando Utilities Commission (OUC) in Orlando, Florida, operated a power plant that was decommissioned. As part of the closure project, it was necessary to remove a leaking 10,000 No. 6 Oil Underground Storage Tank. The groundwater table is high in the area. The work area was bound along one side by railroad tracks, and the area of contaminated soil for removal contained a 30-inch water main.
We performed a site assessment to determine the aerial extent and depth of contaminated soil. The project required the installation of approximately 150 linear feet of sheet piling to a depth of 25 feet along the railroad tracks. We obtained all necessary permits for discharge of the treated groundwater into the City of Orlando Sewer System. We installed a well point dewatering system to depress the water table in the work area to a depth of 15 feet below ground surface, so the contaminated soil would be “dry” in the source removal area. Water pumped during the dewatering process was treated with a Mobile Separator/Carbon Treatment Unit. The excavation proceeded to a depth of 12 feet, and confirmatory soil samples were analyzed to determine that all contamination was removed.
Approximately 2,200 tons of soil were removed and disposed of in a secure landfill. We imported clean fill to restore the work area and installed sod. We then completed the source removal report for the regulatory agency.