Treating Hanford groundwater with state-of-the-art toolsPosted: Updated:
NEAR RICHLAND, Wash.-- Construction is underway to clean up contaminated water that is seeping into the Columbia river, but this project will use state-of-the-art materials.
In addition to using molasses and vegetable oil to treat groundwater near the river corridor, now Hanford is going more hi-tech.
Using a special resin that looks more like sugar crystals, engineers will turn dirty water into the kind you would want to fish in or even drink.
Since July, crews have been working furiously to get a new water treatment facility up and running. They're building near where the old D reactor operated. They plan to have three of the facilities running, at the 100-D, 100-K and 100-H areas.
The problem is not radiation, but chromium. Sodium dichromate protected parts of nuclear reactors by preventing corrosion. But they used hexavalent chromium, chromium with a 6+ oxidation. It is toxic and has contaminated the groundwater. It was the toxic material found in Hinkley, California in 1993, made famous by Erin Brockovich.
"The ground water averages about two times the federal drinking standard," says VP of Soil & Groundwater Remediation for CH2Mhill, Dyan Foss.
That standard is 100 parts per billion. The state requirement is 48 ppb. But some places they've sampled have chromium contamination up to 6000 ppb.
"When the contamination is that high it's the color of Mountain Dew," says Foss. "You wouldn't want to drink it."
The contamination doesn't have a marked affect on human populations. By the time the groundwater seeps into the Columbia River, it becomes diluted and is untraceable if sampled. But it does come through the river beds at a toxicity possibly affecting wildlife living there, like clams and fish eggs.
That's where the resin comes into play. CH2MHill is using a state of the art resin called SIR-700. This resin turns the chromium into a safer form, trivalent chromium. Older resins would have to be replaced about four times each year. The key here is this resin lasts a whole lot longer. In fact, in small testing, they had to stop because the resin would keep doing it's job, almost too well. And that means the project will save millions.
"To the point that we believe that its going to save $20MM in the operational life of this facility," says Foss. "That equates to the construction cost over the lifetime of the project."
The whole project is being funded by recovery, or ARRA money. Hired workers are busy finishing construction, which includes installing over forty miles of piping.
"I'd almost go so far as to call them artisans as you can see all the angles inside all the PVC all the steel sleeves," says facilities manager, Brian Rehberg.
When it's up and running by the end of the year, it will treat six hundred gallons a minute. They expect to clean all of that water by the end of the decade.