The U.S. Department of Energy (DOE) and contractor CH2M HILL Plateau Remediation Company (CHPRC) are safely and compliantly operating the Environmental Restoration Disposal Facility at the Hanford Site in southeast Washington state.
The Environmental Restoration Disposal Facility (ERDF) is a large landfill in the center of the Hanford Site for the disposal of low-level radioactive, hazardous and mixed wastes generated from Hanford cleanup activities. ERDF is composed of eight original disposal cells and two super cells that are twice as large as the original cells. Each super cell is designed to hold approximately 3.6 million tons of material. The original cells were constructed in pairs, with each cell measuring approximately 500 feet wide, 500 feet long and 70 feet deep.
ERDF is regulated by the U.S. Environmental Protection Agency. The facility is designed to keep the environment safe by isolating waste and leachate (rain and dust-suppression water in contact with the waste) from the environment. A double liner/leachate collection system collects and removes leachate from the trench. Leachate is collected and sent to a large water treatment facility in Hanford’s 200 West Area, where contaminants are removed.
After each load is placed into ERDF, it is compacted. Earth movers, each equipped with a global positioning system and computer system, spread and compact the waste to eliminate future subsidence that would damage the final cover. Pipes, boxes and other items are size reduced or filled with grout to also prevent subsidence. Prior to installation of the final cover, a temporary cap is placed over the cells as they are filled.