A new resin used to strip chromium from Hanford groundwater near the Columbia River is saving about twice as much money as estimated, according to Hanford officials.
The Department of Energy and CH2M Hill Plateau Remediation Co. began using the resin at a new plant near the former D and DR reactors in late 2010 and then at a second new treatment facility near the former H Reactor.
It proved so successful that by a year ago, all five "pump and treat" plants removing chromium from groundwater near the river were using it. They pump up groundwater contaminated with hexavalent chromium, treat the water and reinject cleaned water back into the ground.
Sodium chromate used to be added as a corrosion inhibitor to river water used to cool reactors that produced weapons plutonium at Hanford during World War II and the Cold War. It leaked and spilled from transfer systems and piping over decades to contaminate soil and then groundwater near many of the reactors.
When DOE expanded the resin use to all five plants, the switch was projected to save up to $1.6 million a year. But now it is saving more than $3 million annually, officials say.
The new resin, manufactured by ResinTech, has not had to be changed since it was loaded into the first pump and treat groundwater plant at Hanford.
"This means our systems can continue to operate, and we can treat more groundwater," said Dan Neshem, CH2M Hill pump and treat operations and maintenance engineer, in a statement.
It also saves the $10,000 each resin replacement costs.
CH2M Hill estimates that in the last 2.5 years, as all the plants have been switched over, about 600 resin changes have been avoided. That has saved $6 million that can be used for other environmental cleanup at Hanford.
The resin also allows for higher treatment capacity with existing equipment at the older plants. It has increased treatment capacity at one plant by 40 percent, officials say.
-- Annette Cary: 582-1533; email@example.com; Twitter: @HanfordNews