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April 02, 2008 07:44 am
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Photos
Jerry Laizure/The Norman Transcript
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City hopes to put tainted wells back online
By Carol Cole-Frowe
CNHI News Service
NORMAN, Okla. — Norman’s arsenic well water removal project has moved to the next level of approval, which could redeem one of its water wells lost to too-high levels of naturally occurring arsenic.
With modern technology catching up to the challenges of lower arsenic standards set by the Environmental Protection Agency, the city of Norman has long-awaited approval from the Oklahoma Department of Environmental Quality to start production on Well No. 31, which previously has averaged about 230 gallons per minute.
Geri Wellborn, Norman's senior lab technician, said the city is hoping on May 1 to be able to use water from its well at Porter Avenue and Tecumseh Road, courtesy of the ion exchange program.
The water will first come out of the red brick well house and run through underground lines where carbon dioxide will be added automatically to reduce the pH of the water. The process works best at a pH between 7.2 and 7.4, Wellborn said.
Then it goes to three large gray tanks with ferric oxide media inside. The arsenic molecule and all other heavy metal molecules bind to the ferric resin.
The water will go through two of the vessels at the same time. When the media is exhausted, the first vessel is taken off line to fluff the media.
“And we’ll polish the water,” Wellborn said.
Before it enters the distribution system, chloromines and ammonia are added for disinfection.
When the arsenic-removing media has been exhausted, it can be disposed of in the landfill.
“It’s not a hazardous material at this point,” she said, noting that it passed EPA’s Toxicity Characteristics Leaching Procedure or TCLP. “(The arsenic) binds with the iron to the point where it doesn’t leech off freely. … That was one of (Oklahoma Department of Environmental Quality's) major concerns. We don’t want to deal with hazardous waste.”
Now that the water is able to go into Norman’s water distribution system, it can be sold.
Michael Graves of Garver Engineers has been assisting Norman with regulatory issues.
“During this demonstration project, we are generating revenue,” Graves said. “And that’s why there is a regulatory component to this.”
Several other Oklahoma communities are watching the Norman water well results with interest, Graves said. Those include Mustang and Yukon.
“If they can offset future water wells and plant expansions, it could be worth it,” he said.
Norman was the site in March 2006 of the closely watched pilot project at Well No. 7 for the arsenic removal process. The water from that well during the pilot project had to go into the sanitation sewer system to be processed.
Norman lost 13 wells when the EPA implemented its arsenic limits of 10 parts per billion or ppb Jan. 1, 2006, to address health concerns associated with arsenic. The previous limit was 50 ppb.
Another well was lost to too-high fluoride levels and another collapsed because of age.
The equipment to use the arsenic removal technology costs about $400,000, which includes the system, fencing, upgrades and concrete work.
“It’s a toss-up right now,” said Ken Komiske, Norman director of utilities, said of the arsenic removal costs compared with drilling new wells. “But we’re not paying for (the arsenic removal system) — this is like a test drive. It’s a no-lose situation for the city and it’s an excellent opportunity.”
The demonstration project will be evaluated at the end of a year, at which time Norman can decide if it’s cost effective to continue to use it, implement it on other wells or discontinue it.
Some other states where water with too much arsenic is being treated and used include Arizona, New Mexico, Texas, New Mexico, New Jersey and Pennsylvania.
“It’s not new. … We made a point when we did this of installing something that had a track record,” Wellborn said.
Carol Cole-Frowe writes for The Norman (Okla.) Transcript.
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