Superfund Record of Decision (EPA Region 4): Oak Ridge Reservation (USDOE), (Operable Unit 4), Roane County, Oak Ridge, TN. (Third remedial action), September 1991

The Oak Ridge Reservation (ORR) (USDOE) (Operable Unit 4) site is a former uranium isotope processing subsite in Oak Ridge, Roan County, Tennessee. The 1,700-acre K-25 site, which comprises Operable Unit 4 (OU4), is one of several hundred waste disposal sites or areas of contamination at the ORR site requiring Superfund remedial action. Land use in the area is predominantly residential. The storage yards contain 36,000 ninety-gallon drums of stabilized sludge, 29,000 ninety-gallon drums of raw sludge, and 16,000 gallons of raw sludge in tanks, contaminated with mixed radioactive and hazardous wastes. The Record of Decision (ROD) addresses the sludge stored at the storage yards as an interim action to prevent or mitigate releases to the environment. The selected remedial action includes eliminating free liquids in sludge through filter press, thermal drying, or similar methods; repacking dry sludge, followed by onsite storage of containers and processing liquids removed from the sludge through existing treatment facilities