Record amount of contaminated Hanford ground water treated

Hanford set a record for the most contaminated ground water treated in a month, cleaning 100 million gallons of water in November.

With the help of two new treatment plants along the Columbia River, enough water was cleaned to drinking water or stricter standards in November to fill more than 150 Olympic-size swimming pools, according to CH2M Hill Plateau Remediation Co.

The Department of Energy's goal is to treat ground water near the Columbia River and treat or contain ground water in central Hanford to prevent it from reaching the river, said Briant Charboneau, DOE project director.

Changes to the legally binding Tri-Party Agreement have accelerated the cleanup of ground water, said Dieter Bohrmann, spokesman for the Washington State Department of Ecology, a Hanford regulator.

In addition, federal economic stimulus money is helping DOE to ramp up treatment to help meet the accelerated schedule, he said.

"We're on schedule to maximize our systems and reach a capacity to treat 2.4 billion gallons of ground water annually by 2015," said Dyan Foss, CH2M Hill vice president of soil and ground water remediation, in a statement.

Hanford now has six pump and treat plants, which pump contaminated water out of the ground beneath Hanford and treat it before injecting clean water back into the ground through wells.

This spring a seventh treatment plant is scheduled to begin operating in central Hanford. It will be the nuclear reservation's largest and most sophisticated treatment plant, capable of removing eight radiological or hazardous chemical contaminants from ground water.

The plant, which is anticipated to treat 2,500 gallons of contaminated water per minute, was built with $80 million in American Recovery Act money. A smaller plant already is operating in central Hanford, treating ground water for radioactive technetium 99 and four chemicals.

One of the two new ground water treatment plants along the Columbia River also was built with Recovery Act money.

A new pump and treat plant near the former D and DR reactors built with federal economic stimulus money began operating around the first of the year, and a second pump and treat plant near the former H Reactor began operating this fall.

Together they cost about $45 million, but a better resin used to clean the water at the plants is expected to cost about $40 million less during the lifetime of the plants than a resin previously used at Hanford. Its purchase price is lower and it also needs to be replaced less frequently.

Like three other pump and treat plants along the Columbia River, they remove hexavalent chromium to aquatic standards, which are stricter than drinking water standards. The chemical is a carcinogen to humans, but can be toxic to fish in smaller concentrations.

Together, the two new pump and treat plants treat a plume of chromium near the horn of the Columbia River as it cuts through Hanford. Chromium was added to cooling water at Hanford's plutonium-production reactors to prevent corrosion.

During more than 30 years of plutonium production at Hanford for the nation's defense program, about 450 billion gallons of contaminated liquids were discharged directly into the soil through evaporation ponds and infiltration systems, according to CH2M Hill. That's about the amount of water needed to supply the United states with agriculture, industrial and other uses for a day, it said.

To date, more than 5 billion gallons of ground water have been pumped out of the ground and treated.

Hanford also is working to remove contaminated soil or to extract contamination from the soil to prevent further contamination of ground water.

While DOE once estimated that 80 square miles of ground water beneath Hanford were contaminated, it has reduced that estimate to 65 square miles. The reduction is due to treating ground water, the decay of radioactive tritium and the natural attenuation of contamination, said DOE spokesman Geoff Tyree.

-- Annette Cary: 582-1533; acary@tricityherald.com; more Hanford news at hanfordnews.com