HANFORD — The first of two new water treatment plants along the Columbia River at Hanford has begun removing chromium from ground water.
When both are operating, the treatment capacity along the river will be tripled, according to contractor CH2M Hill Plateau Remediation Co.
"We're increasing the amount of ground water we're treating so we can stop chromium in the aquifer from reaching the Columbia River," said Briant Charboneau, Department of Energy director for soil and ground water, in a statement.
The Department of Energy used federal economic stimulus money to build the first of the two plants, which is near the D and DR reactors. The second is under construction just down river near the H Reactor. Together they cost about $45 million.
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Together they will treat a plume of contamination that has spread between the two reactor areas at the horn of the river as it cuts through the nuclear reservation.
Chromium was added to cooling water at Hanford's plutonium-production reactors to prevent corrosion. The water with the chromium then was discharged into the soil and more of it leaked from piping, staining the soil bright yellow.
It can cause cancer in humans and is particularly toxic to fish and other aquatic life.
The "pump and treat" technology used at the new plants has proved its worth in mopping up chromium near the river for more than a decade. But with major work done to dig up contaminated soil that can spread contamination to ground water, the treatment plants should be able to get ahead of the problem.
DOE plans to restore the ground water to federal drinking water standards within a decade.
The new plant at the D and DR reactor uses 41 wells to pump contaminated water out of the ground and treat it to convert chromium to a less toxic form at a rate of up to 20 million gallons per month. The treated water is then returned to the ground in 14 injection wells.
The project includes an 11,400-square-foot plant and 40 miles of piping.
The plant near the H Reactor will have 58 miles of piping and 44 extraction and injection wells. Together they will treat 50 million gallons of water a month.
They will replace a small system that has been treating the plume since 1997.
The new plant near the D and DR reactors is using a a new resin in its ion exchange treatment system that is expected to reduce operating costs longterm by about $20 million. The resin now commonly used in Hanford pump and treat plants has to be replaced four times a year, but the new resin may last four times as long.
That reduces not only the purchase price but also the costs to change out the resin.
Using federal economic stimulus money allowed the plant near the D and DR reactors to be built and start operating sooner than planned, said Kent Dorr, vice president of CH2M Hill engineering, projects and construction. DOE was not required to have the plant operating under the Tri-Party Agreement for almost two more years.
When the treatment plant near H Reactor comes online, five pump and treat plants will be operating along the Columbia River at Hanford.
-- Annette Cary: 582-1533; email@example.com; Find related stories at www.hanfordnews.com