The massive, lined landfill in central Hanford now holds 15 million tons of waste, much of it with low-level radioactive and hazardous chemical contamination, the Department of Energy announced Tuesday.
As workers and guests watched from the rim of the 70-foot-deep landfill, a bright orange container at the bottom of the landfill was tipped up. About 20 tons of contaminated soil and a plastic liner for the container spilled onto the floor of the massive landfill.
It may not have been exactly the load that reached the 15-million-ton mark, but Teamsters celebrated by blaring the horns of the trucks used to haul waste.
"Without ERDF, Hanford cleanup would look nothing like it does today," said Dennis Faulk, Hanford program manager for the Environmental Protection Agency, a Hanford regulator.
ERDF, or the Environmental Restoration Disposal Facility, has been called the heart of Hanford cleanup, the backbone of Hanford cleanup and the hub of Hanford cleanup, he said.
Hanford produced nearly two-thirds of the plutonium for the nation's nuclear weapons program, starting during World War II. But with the end of the Cold War, work is under way to clean up the extensive environmental contamination across its 586 square miles.
The landfill is the largest disposal facility in the nationwide DOE cleanup complex. Its disposal area covers roughly the same area as 52 football fields, although some areas already filled are covered with a temporary cap.
Hundreds of buildings have been torn down. Contaminated soil has been dug up. And debris has been retrieved from former disposal sites that do not meet modern environmental standards.
If the waste qualifies as routine industrial waste, low- level radioactive waste or hazardous chemical waste, it has been hauled to the central Hanford landfill for permanent disposal. Hazardous materials such as mercury, asbestos, beryllium, chromium and lead are treated at the landfill before disposal.
"We are removing contamination away from the river that could be a threat to the river in the future," said Matt McCormick, manager of the DOE Hanford Richland Operations Office.
Much of that work to date has been on Hanford land closest to the Columbia River, and about 13.5 million tons of the waste disposed of in the landfill has come from those areas, said Carol Johnson, president of DOE contractor Washington Closure Hanford.
Some of the waste was once in areas along the river where groundwater, which moves toward the river, is just 30 feet below the surface. Groundwater in central Hanford is about 300 feet below the surface, according to Hanford officials.
Much of the threat to the groundwater comes as precipitation or other water carries contamination deeper into the ground.
At ERDF, a lining system below the landfill collects about 150,000 gallons of water a month, which includes precipitation and water sprayed in the landfill to keep down dust and prevent the spread of contamination.
When the landfill is closed, it will be covered with a cap to keep precipitation from reaching the waste.
Creating the landfill was controversial because it meant disposing of waste in the Tri-City's backyard.
But the Hanford Advisory Board supported it, saying in 1994 that the landfill was needed. But it also said the landfill should only be used for Hanford waste, a policy that DOE adopted.
On ERDF's first day of operation in 1996, a single container of waste was emptied into the landfill. Within a week, that was up to 10 containers, Faulk said. Containers have a capacity of 25 tons, but typically hold about 18 to 23 tons.
That increased to 854 containers delivered by careful choreography of truck deliveries in a single day in April 2011, as nearly $2 billion in economic stimulus money speeded up Hanford work.
Now disposal of 250 to 350 containers a day is more typical, according to Washington Closure.
That will gradually slow over the next few years as much of Hanford cleanup along the river is completed in 2015. But as that cleanup is mostly finished, DOE plans to turn to cleanup in central Hanford, hauling more building rubble and contaminated soil to the landfill.
The landfill now employs up to 150 workers and requires 70 trucks to haul waste from across Hanford to ERDF and distribute it in the landfill. Waste transport drivers have logged 22 million miles since the landfill opened, with only two accidents serious enough to record with the Department of Transportation, according to Washington Closure.
The landfill now has the capacity to hold 18 million tons, after several expansions since 1996. McCormick expects the next expansion to be needed in about 2018-19.
-- Annette Cary: 582-1533; firstname.lastname@example.org; Twitter: @HanfordNews