The cleanup mission at the Department of Energy’s (DOE) Idaho National Laboratory Site officially began in 1989 when the Idaho National Laboratory was added to the Environmental Protection Agency’s National Priorities List of Superfund Sites due to suspected and confirmed historical contaminant releases to the environment.

Of principle concern was the Site’s impact on the underlying Snake River Plain Aquifer, a sole-source aquifer and primary drinking and agricultural water source for more than 300,000 Idahoans. The past use of unlined wastewater disposal ponds, industrial injection wells, accidental spills, and waste discharges created contaminant plumes underneath the 890-square-mile Site.

The EPA, state of Idaho, and DOE signed the Federal Facility Agreement and Consent Order (FFA/CO) and associated Action Plan on December 9, 1991. This legally binding cleanup agreement outlined the process and schedule for investigating suspected and confirmed contaminant release sites, and required the DOE to annually request the necessary funding to carry out the cleanup mission.

As a Superfund site, the DOE and its contractor conduct “risk-based cleanup.” In the simplest terms, if a confirmed contaminant release site poses an unacceptable risk to either people or the environment, it requires cleanup or the establishment of controls to keep people, plants, or animals from coming into contact with the waste. If a site poses little to no risk, either limited or no action is taken. Such an approach allows DOE to direct cleanup funds to areas of the Site that pose an unacceptable risk to people or the environment.

Since 1991, the EPA, state of Idaho, and DOE have signed 28 records of decision on individual contaminant release sites and entire facilities at the Site. More than $12.6 billion since 1997 has been spent on environmental cleanup thus far. Cleanup actions continue at Test Area North, the Idaho Nuclear Technology and Engineering Center, and the Radioactive Waste Management Complex.