| Hanford, Washington. Water Treatment Proceeds |
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Ground water treatment proceeds at Hanford Hanford, Washington March 17th, 2010 HANFORD — Cleanup of contaminated Hanford ground water along the Columbia River is expanding from work to keep contamination from entering the river to cleaning up the contaminants for good. The latest project is building a larger "pump and treat system" near Hanford's D and DR reactors that will pump water out of the ground, remove hexavalent chromium and then reinject the clean water into the ground. The work is being done with federal economic stimulus money. Another pump and treat system is to be built near the H Reactor just down river. Together, the two systems 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. Pump and treat has proved its worth in mopping up hexavalent chromium near the river over more than a decade. But with major work accomplished to clean up contaminated soil that can spread contamination to ground water, Department of Energy officials are taking the next step. "We contained it while we were doing source removal," said Briant Charboneau, DOE project director for ground water waste remediation. "Now that the source removal is coming to completion in the next few years, we will be able to restore ground water to drinking water standards." Removal of contaminated soil should be completed by 2015. And the ground water should be restored to federal drinking water standards within 10 years, he said. As an added benefit, CH2M Hill Plateau Remediation Co. believes the new pump and treat system for D and DR reactors will be less costly to operate. It will cost $20 million to design and construct, but using a new type of resin should save at least $20 million during its operation, said Dyan Foss, CH2M Hill vice president for soil and ground water remediation. The chromium is captured and converted to a less toxic form in the treatment system as it combines with a resin in an ion exchange process. The resin now commonly used at Hanford has to be replaced four times a year, Foss said. But in small-scale tests, the new resin, which looks like yellow Pop Rocks, lasted so long that tests were stopped before it failed. In actual use, CH2M Hill is counting on it lasting three or four times as long as the current resin. That reduces not only the purchase price, but also the costs to change out the resin, Charboneau said. The new pump and treat system near the D and DR reactors also will be much larger than the one it replaces, which began treating water in 1997. The current system has 10 wells to extract ground water and reinject it into the ground and treats 50 gallons of contaminated water a minute. When the new system starts operating at the end of the year, it will use 53 wells and treat 600 gallons of water per minute. Work was done last year to expand pump and treat upriver near the K and K West Reactors and next year work will start on the new system for H Reactor. Together they will help DOE meet new aggressive deadlines for ground water cleanup in the legally binding Tri-Party Agreement. The deadlines call for contamination entering the river to be at 10 parts per billion or less by 2012 to protect fish and other aquatic life. In 2020, the contamination plume inland must be reduced to the federal drinking water standard of 100 parts per billion or less. The pump and treat systems would continue to operate to 2025 to ensure that the ground water is thoroughly cleaned up. Now the plume averages about twice the federal drinking water limit and spikes periodically in places to as much as 10,000 parts per billion. About 60 people, most organized labor craft workers, have been hired with economic recovery money to build the new treatment plant, along with installing piping and wells, at the D and DR reactors. Among them is Sam Johnson, who was hired in September after graduating with a master's degree in mechanical engineering. No one else was calling him back to offer a job during the bad economic times, he said. Another new worker is Harry Alden, a Richland pipefitter, who could find work in just four months last year. "It's a heck of a deal," he said about economic recovery act jobs. When work is completed at the D and DR reactor, some of the new workers are expected to be transferred to a new pump and treat system being built in central Hanford with economic stimulus money to treat a wide variety of contaminants. Then they may get additional work building the H Reactor pump and treat system. Together, the treatment systems for the H Reactor and D Reactor areas will use 100 wells and 100 miles of piping to treat 1,300 gallons of contaminated water per minute. Read more: http://www.thenewstribune.com/2010/03/17/v-printerfriendly/1112548/ground-water-treatment-moving.html#ixzz0j35Rd3iD |
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