Hanford’s Environmental Restoration Disposal Facility in the center of the Hanford Site is a massive landfill regulated by the U.S. Environmental Protection Agency. Built in 1996, ERDF accepts low-level radioactive, hazardous, and mixed wastes that are generated during the cleanup activities at the Site. It does not accept any non-Hanford waste.
Designed to be expanded as needed, ERDF comprises a series or cells or disposal areas. Each pair of cells is 70 feet deep, and 500 feet by 1,000 feet at the base – large enough to hold about 2.8 million tons of material.
The fourth and largest expansion of ERDF was completed in January 2011. Two “super cells,” each the equivalent of a pair of existing cells, were constructed using Recovery Act funds. Additional upgrades included new maintenance facilities, additional dump ramps and additional transfer areas for waste containers – all of which will enhance the safety of increased, daily operations.
With the addition of super cells 9 and 10, ERDF capacity is 16.4 million tons. At the 70-foot-base, ERDF covers the same areas as 52 football fields. To date, nearly 11 million tons of contaminated material has been disposed in the facility.
One of the key components of ERDF is the liner that is built into each cell. The liner consists of multiple layers of plastic and other impermeable materials and a system to collect and removed liquids as they drain through the waste materials. ERDF does not accept liquid waste for disposal, but water enters the facility when it rains and snows, and water also is used for dust control during routine operations. The collected water, or leachate, is collected and routed to an onsite treatment facility. After treatment, the liquid is clean enough to be returned to the ground with no harm to the environment.
ERDF accepts waste from throughout Hanford which is brought to the facility by a fleet of trucks traveling between the waste sites and the landfill. Drivers have logged more than 12,000,000 miles since the facility began accepting waste in 1996. Soil that is contaminated, waste that has been dug up, and debris from building demolitions are transported to ERDF for permanent disposal. Up to 600 truckloads of waste can be placed into the facility each day. Not only does the system keep Hanford waste on the Hanford Site and away from the Columbia River, major roads, and members of the general public, it also saves the DOE from having to pay to transport the waste to an offsite disposal facility. ERDF disposal costs are significantly below those of other disposal facilities, including municipal landfills.
After each load is placed into ERDF, it is compacted. Earth movers equipped with high-tech ground monitoring equipment drive over the waste to eliminate any air pockets or gaps in the landfill. Hollow tubes or pipes are either filled with a cement material or are cut into pieces. This ensures there are no void spaces in the facility, which could result in the landfill “sagging” or settling, which could cause damage to the permanent cap that ultimately will cover the entire facility when it is no longer needed. In the meantime, a temporary cap is placed over cells as they are filled.
