September 22, 2004
Hanford's Environmental Restoration Disposal Facility (ERDF) is celebrating the disposal of five million tons of contaminated materials that came from waste sites, burial grounds, and contaminated facilities located along the Columbia River.
Hanford River Shore Cleanup Reaches Half-way Mark
Five million tons also equates to half of the estimated 10 million tons of contaminated materials located along the river corridor.
"We've had an extremely aggressive schedule to clean up waste sites and remove contaminated materials away from the river," said Tom Logan, president for Bechtel Hanford. Bechtel manages the Environmental Restoration Project and ERDF for the U.S. Department of Energy.
"In accelerating river corridor cleanup, the half-way point marks an important milestone in reducing risk to workers, the public, and the river," Logan said.
We have never had a lost-time injury in the nearly eight years of ERDF operation," Logan said. "This is a clear indication that it's possible to accelerate cleanup and reduce risk in a cost-effective manner at Hanford."
ERDF is a large disposal facility located in the center of the Hanford Site that began operation in 1996. ERDF comprises four "cells," with two more under construction and nearly complete. Each cell is 500 by 500 by 70 feet deep and constructed with a liner system to provide an impermeable layer of protection.
The bottom liner is designed to catch any moisture from precipitation, as well as water used for dust suppression while placing the waste into ERDF. The base is made of compacted clay. On top of that are layers of high-density polyethylene, and perforated drainage pipes in gravel to collect any water that gets through. It's topped with a 3-foot layer of dirt to protect the drainage and liner system as trucks drive over it. The waste itself is compacted in two, 35-foot-thick layers separated by two feet of clean fill. The cells are built two at a time. The first two cells went into operation in 1996 with two more cells added in 1999. Each pair of cells is large enough to hold 2.8 million tons of waste material. Together, the capacity of the four cells is 5.2 million tons, which will be reached by March 2005.
Each day, about 150 truckloads, or 3,000 tons, of low-level radioactive and hazardous waste, rock, soil and other debris are disposed at ERDF. The wastes are from excavation of cleanup sites along the Columbia River, demolition and cocooning debris from Hanford's old production reactors and other facilities, and waste material generated by other Hanford contractors. Once the waste is collected, it is placed into containers, or cans, that hold up to 19 tons. The cans are hauled from the dig sites to nearby staging areas, and from there to the ERDF container transfer area.
Once in the transfer area, the cans are taken into ERDF, dumped, and delivered back to the container transfer area. The empty cans then are delivered back to the dig sites, or wherever they are needed, and the process begins again. Drivers of the trucks recently reached a milestone of their own when they logged 8 million miles in the cleanup effort.