The Department of Energy has been given three more years to meet milestones for building additional caps over contaminated soil in Hanford tank farms after it became apparent the agency could not meet the project’s previously set deadlines.
DOE built two waste barriers the size of football fields or larger in 2007 and 2010. Under the Tri-Party Agreement with Washington state and the U.S. Environmental Protection Agency it was to have two more built in October 2015, another by this week, and the fourth a year from now.
The revised milestones call for construction to be completed on the first two of the additional four barriers in October 2018. The remaining two are required to be built in October 2019 and October 2020. The caps already built use a layer of polyurea plastic or asphalt with polymers as covering to keep rain or snowmelt from seeping through the soil and spreading tank waste contamination deeper into the ground.
DOE and the Washington state Department of Ecology spent more than a year discussing the proposed changes. Ecology levied a $5,000 fine against DOE, accusing the federal government of failing to meet its requirement to disclose the milestone was at risk from October 2014 through March 2015. DOE agreed to pay $2,500 in late September to settle the matter, but denied that it had failed to disclose information. The document resolving the dispute, which was signed by the state and federal agencies, said the matter was being settled to avoid the expense of litigation and to resolve any administrative or judicial claims.
The Department of Energy said in documents related to the fine that Congress’ failure to pass a DOE budget for fiscal 2015 left the tank farm budget at fiscal 2014 levels under a continuing resolution. The federal agency thought it could still meet the milestones through efficiencies instituted by spring 2015, but then faced the cost of emptying Tank AY-102, the Hanford double-shell tank with an interior leak, and additional expenses to protect tank farm workers from chemical vapors.
The next milestone under the revised Tri-Party Agreement requires a decision on locations for the third and fourth barriers yet to be built by September 2017. The first two of those caps have been designed and are planned for the SX Tank Farm. That tank farm was picked because of the amount of leaked or spilled contamination and the contamination’s location closer to the surface of the ground than in some other tank farms, according to the Department of Ecology.
The first of the barriers already built covers about 70,000 square feet at the single-shell T Tank Farm, Hanford’s oldest tank farm. It covers all or part of the area around 10 tanks. While the barrier’s target was T Farm’s Tank T-106, believed to have leaked an estimated 115,000 gallons of waste in 1973, the cap also covers part of the area around Tank T-111.
Tank T-111 was discovered to be leaking in 2013. The second barrier built covers the six tanks of the TY Tank Farm.
