Hanford’s Environmental Restoration Disposal Facility is in the 200 area of the Hanford Site and is a massive landfill regulated by the U.S. Environmental Protection Agency under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). Built in 1996, ERDF accepts low-level radioactive, hazardous, and mixed wastes that are generated during the cleanup remediation activities at Hanford. It does not accept any non-Hanford waste.
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 day-to-day operations.
With the addition of super cells 9 and 10, ERDF capacity is about 20 million tons and covers approximately 107 acres. To date more than 18 million tons of low-level radioactive, hazardous, and mixed wastes have been disposed of in the facility.
One of the key components of ERDF is the double-layered liner built into each cell. The liner consists of multiple layers of polymeric and other impermeable materials with a Leachate system to collect and treat liquid effluent. ERDF does not accept liquid waste for disposal, but water enters the facility when it rains and snows. Additional water is used for dust suppression during routine operations and stabilizing fixative is used to treat the waste during disposal. The collected liquid, or leachate are collected then routed to an onsite treatment facility. After treatment, the liquid is clean to residential standards enough to be returned to the ground with no harm to the environment.
ERDF accepts waste from throughout Hanford that is transported to the facility by a fleet of roll on-roll off (RORO) disposal 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. Each transported waste is verified to meet the waste acceptance criteria prior to being sent to ERDF and is confirmed upon receiving. Soil that is contaminated, waste that has been excavated, and debris from building demolitions are transported to ERDF for permanent disposal. Up to 600 truckloads of waste can be disposed of each day. The waste transportation system keeps Hanford waste on the Hanford Site; away from the Columbia River, major roads, and members of the general public.
After each disposal is placed into ERDF, it is compacted. Compactors equipped with high-tech ground monitoring equipment compact the waste to eliminate any voids in the landfill and provide safe conditions for layering future waste. Hollow items are grouted with either a cement or fixative, while long length items are grouted in place until full compaction is reached. 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. After a cell reaches capacity, a temporary cap is placed over cells until final closure is reached.