Hanford site treating record amount of contaminated groundwater

RICHLAND, Wash. - U.S. Department of Energy (DOE) contractor CH2M HILL Plateau Remediation Company (CH2M HILL) has exceeded this year’s goal for treating 1.4 billion gallons of contaminated groundwater at the Hanford Site in Washington state.

DOE’s goal was to treat 1.4 billion gallons by the end of the fiscal year, which runs from October 2012 to September 2013. CH2M HILL met this key performance goal three months ahead of schedule in June and has removed approximately 36 tons of contaminants so far this fiscal year. This goal was met ahead of schedule because the startup of a major new treatment facility has progressed more quickly than anticipated and the contractor has operated treatment facilities more efficiently.

CH2M HILL also exceeded last year’s treatment record of 1.2 billion gallons. To date, Hanford contractors have treated approximately 7.8 billion gallons of groundwater and removed approximately 55 tons of contaminants, including nitrate, carbon tetrachloride, hexavalent chromium, uranium, and technetium-99.

Six systems treat groundwater at Hanford. They are called pump and treat systems, because groundwater is pumped up through wells and treated to remove contaminants and shrink plumes. Plumes are areas of contaminated groundwater located underground in the center of the site and along the Columbia River, which runs through the Hanford Site.

The groundwater contamination resulted from operations to produce plutonium from the 1940s through the end of the 1980s. The discharge of liquids, some contaminated with chemicals and radionuclides, to soil disposal sites resulted in large plumes of contaminated groundwater. An estimated one million gallons of waste that leaked from underground tank systems during the Cold War also caused smaller contamination plumes in groundwater near the tanks. Treatment systems remove contaminants from groundwater using ion exchange columns, fluidized bed reactors, and membrane bioreactors.

In the last three years CH2M HILL has more than doubled the groundwater treatment capacity at the Hanford Site, from 600 million gallons a year to 1.4 billion gallons a year.