Hanford Site Treats Record Amount of Contaminated Groundwater
CH2M Hill treated 1.4 billion gal of groundwater between October 2012 and June 2013
U.S. Department of Energy (DOE) contractor CH2M HILL Plateau Remediation Co. (CH2M HILL) has exceeded this year’s goal for treating 1.4 billion gal of contaminated groundwater at the Hanford Site in Washington state.
DOE’s goal was to treat 1.4 billion gal 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 gal. To date, Hanford contractors have treated approximately 7.8 billion gal 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 under the center of the site and along the Columbia River, which runs through the Hanford site.
The amount of groundwater treated through the end of June is enough to fill more than 2,100 Olympic-size swimming pools or more than 500,000 standard water trucks. If parked end to end, they would stretch across the U.S. from Washington state to New York state.
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 1 million gal 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 gal a year to 1.4 billion gallons a year.
DOE’s Richland Operations Office is responsible for several major cleanup projects on the Hanford site, including cleanout and demolition of the high-hazard plutonium finishing plant, demolition of excess facilities, excavation of contaminated soil and solid waste, and treatment of contaminated groundwater, as well as Hanford site infrastructure. The office oversees approximately $1 billion in annual funding for Hanford site work that is conducted by a federal and contractor workforce of approximately 4,200 personnel.