Workers at the Hanford Site in Washington state met the Department of Energy’s fiscal 2018 goal of treating 2.2 billion gallons of contaminated groundwater early, despite some downtime or limited operations at treatment plants to make improvements.
Contractor CH2M Hill Plateau Remediation Co. hit the goal nearly two months before the Sept. 30 end of the fiscal year. It removed 90 tons of contaminants, according to DOE.
The improvements made to Hanford pump-and-treat plants will allow groundwater treatment to continue at a rate of 2.2 billion gallons a year, said Michael Cline, federal project director for soil and groundwater remediation at Hanford. The 580-square-mile former plutonium production complex has plumes of contaminated groundwater totaling 65 square miles. Since treatment began in the mid-1990s, about 19 billion gallons of groundwater have been treated and 435 tons of contaminants removed.
In the past 10 months, upgrades were made to the fluidized test bed reactor at Hanford’s largest and most sophisticated groundwater treatment plant, the 200 West Pump and Treat Facility. The central Hanford facility removes more than a half-dozen contaminants from groundwater, including carbon tetrachloride and uranium. Its fluidized test bed reactor is used to remove carbon tetrachloride and nitrates. The improvements should shorten the time it is down for maintenance, Cline said.
“We continually look for ways to make improvements and ensure our groundwater treatment network continues performing well,” he said.
Other improvements at the plant and five pump-and-treat facilities along the Columbia River included replacing filters with newer and more efficient filters and replacing polyvinyl chloride piping with stainless steel piping at stress points in the water treatment plants, Cline said. The five treatment facilities on the river remove hexavalent chromium from groundwater. The chemical was added to reactor cooling water to prevent corrosion.
