RICHLAND, Wash. –The Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA), in coordination with the Washington Department of Ecology, have made plans for remediating contaminated soil at four locations in the center of the Hanford Site. The agencies have chosen to pursue a combination of alternatives: retrieving, treating, and disposing of contaminated soil; extracting contamination through an air-handling system; and maintaining a soil barrier over some of the contaminated soil.
Large volumes of liquid waste were generated when plutonium was produced at the government site in southeast Washington State during World War II and the Cold War. The liquids came from plutonium processing facilities within a 10-square-mile area known as Hanford’s Central Plateau Inner Area. The area is located about seven miles from the Columbia River, which runs through the Site.
Liquids containing low levels of plutonium and other contaminants were disposed directly to underground structures in the soil, such as ditches, contaminating the underlying soil. These areas of contaminated soils have been identified as waste sites that require remediation.
The cleanup decision made this week by DOE and EPA – with input from the State of Washington, tribal nations, the State of Oregon, and the public – covers 21 waste sites in four areas of the Central Plateau Inner Area. The Inner Area will serve as the final Hanford Site footprint for long-term waste management. The overall objective is to make the final footprint as small as practical.
“This decision balances public sentiment for digging deeper with a science-based cleanup action that will protect human health and the environment” said Matt McCormick, Manager, DOE Richland Operations Office. “This decision was based on the anticipated future use of this area of the Hanford Site. We anticipate the Central Plateau Inner Area will be a long-term, waste-management area, under the control of the U.S. government.”
“Finalizing this decision was challenging, because remediating plutonium-contaminated waste sites is a highly charged topic,” said Emerald Laija, Environmental Scientist, EPA. “It is important that we now have another final cleanup decision for Hanford's Central Plateau.”
Contaminated soil that is dug up will be disposed of in facilities on and off the Hanford Site. The disposal destination will depend on how and where the soil is treated and whether the soil contains materials that need to be disposed of at a national repository for waste contaminated with plutonium. The air-handling system consists of an existing soil vapor extraction (SVE) system that is being used to address hazardous chemicals at some of the waste sites, specifically volatile organic contaminants of carbon tetrachloride and methylene chloride.
A Record of Decision under the Comprehensive Environmental Response, Compensation, and Liability Act ( CERCLA), commonly known as Superfund, will be posted to www.hanford.gov, or click on this link to go directly to the document: http://ow.ly/6R00P.