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Wednesday, March 12, 2008 - Page updated at 12:00 AM

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Agency speeds up Hanford water cleanup

The Associated Press

YAKIMA — The federal government is accelerating cleanup of one plume of contaminated groundwater at the nation's most contaminated nuclear site in an effort to better protect aquatic life in the neighboring Columbia River.

The project will triple the amount of groundwater treated for hexavalent chromium, a cancer-causing agent that was used as a corrosion inhibitor in nuclear reactors, at south-central Washington's Hanford nuclear site. The contaminant moves easily with water and is particularly dangerous to salmon in the region's largest waterway.

"Accelerating this work emphasizes our commitment to clean up and directly supports our goal to stop key contaminants from reaching the Columbia River," Briant Charboneau, the U.S. Department of Energy's project director for groundwater remediation, said in a statement Tuesday.

"We're using this opportunity to step up our activities and bring us closer to our groundwater-remediation goal," he said.

The federal government created Hanford in the 1940s as part of the top-secret Manhattan Project to build the atomic bomb.

Plutonium production for the nation's nuclear-weapons program continued there for four decades, leaving an estimated 80 square miles of groundwater contaminated at levels exceeding state and federal drinking-water standards.

The hexavalent chromium contamination near the K East Reactor resulted from discharges of reactor effluent into a long trench next to the Columbia River.

The plume stretches along 1 ¼ miles of the rivershore. Very little of the contamination closest to the river exceeds the federal drinking water standard of 100 parts per billion, while about half of it away from the river exceeds the standard, said Larry Gadbois, environmental scientist with the Environmental Protection Agency.

However, the area closest to the river exceeds the more stringent standard for freshwater aquatic life — 10 parts per billion.

New wells and additional equipment will allow the contractor hired to handle the groundwater cleanup, Fluor Hanford, to triple the amount of groundwater it can treat, from 300 gallons per minute to 900 gallons per minute.

"This isn't just a little increase. This is a major increase, that should not only capture the plume, but pump the water hard enough that this will really help restore the aquifer," Gadbois said.

A 2004 audit by the Energy Department's inspector general criticized the agency's groundwater-cleanup efforts, finding the pump-and-treat systems to treat groundwater had been largely ineffective. Those systems pump water out of the ground, treat it with chemicals to remove the contaminants and inject it back into the ground.

However, Gadbois said the method has worked quite well for chromium. A similar plume at the 100 H Reactor is nearly cleaned up, and the plume at K East Reactor has been reduced by about one-third.

Accelerating groundwater cleanup has been a point of discussion among the Energy Department, EPA and Washington state officials in recent months amid negotiations over the Tri-Party Agreement, the 1989 pact that governs cleanup of the site.

The document has seen numerous changes over the years, but the Energy Department has recently proposed some significant deadline changes. Among the things the state has sought in return is an acceleration of groundwater cleanup to better protect the Columbia River.

Copyright © 2008 The Seattle Times Company

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