Last week, the city of Helen shut down one of its five wells after a radioactive gas, radon, was detected in the water.

Helen city manager Jerry Elkins said the city should be able to get along fine with its remaining four wells. But the situation is a reminder that radon can be found not just in the air but also in water, and at high levels it can be a threat to human health.

"We voluntarily shut (the well) down, just to be on the safe side," said Elkins, adding that the Georgia Environmental Protection Division has asked the city to retest the well, to make sure the initial reading was correct.

Though located directly on the Chattahoochee River, Helen does not withdraw water from it and relies on wells for its water supply.

The affected well, located in the Innsbruck subdivision, is by far the lowest producing of the five, Elkins said.

"We only get about 5,000 gallons out of it every three days," he said. "None of that water is pumped to downtown, and only about 10 percent of the water that goes to Innsbruck is produced from that well."

He said the Innsbruck community has approximately 200 homes. But even if the well contains radon, Elkins said he believes the health risk to residents is low. "The water is mixed with water from other wells, so by the time it reaches people's houses it is very diluted," he said.

If the well is proven to be contaminated, Elkins said, the city will probably shut it down permanently rather than spend money trying to fix the problem.

He said Helen is already testing sites for a new well.

"We will have a new elevated water tower, and we'll be putting in a booster pump to move water from downtown to the Innsbruck tank," he said.

Elkins said Helen is in no danger of running low on water, even with Oktoberfest beginning this week. In an emergency, he said, the city would be able to connect with a pipeline from the White County Water Authority.

Communities that get their water from a surface source, such as a river or reservoir, don't have to worry about radon in the water. According to the U.S. Environmental Protection Agency, most of the gases in surface water dissipate into the air even before the water reaches a treatment plant.

But residents whose water comes from a well may have reason to be concerned. Radon gas, which is invisible, odorless and tasteless, is created by the breakdown of uranium in rocks underground.

Usually, radon gets into a home by seeping up from the soil into the air. But radon can also dissolve into
groundwater. If your house uses well water, radon can be released from the water into the air every time you shower or wash dishes.

These radioactive particles can become lodged in your lungs when you breathe. Radon is the second-leading cause of lung cancer in the U.S., surpassed only by smoking. According to the EPA, radon kills about 20,000 people a year.

And the longer you live in a radon-contaminated home, the greater your exposure.

"It's cumulative, permanent damage," said Ginger Bennett, radon educator for Hall County's Extension office. "But radon doesn't produce any symptoms until lung cancer develops."

If the air in your home tests negative for radon, she said, there's probably not any radon in your water.

"It's expensive to test well water," she said. "We recommend that you test the air first."

Bennett's office distributes free, easy-to-use kits for testing household air quality, available to anyone in Northeast Georgia.

"In five years, we've given out about 30,000 kits," she said. "But only about 30 percent are actually used."

Some residents may believe there's no point in testing their home for radon if there's nothing they can do to fix the problem when it's found.

"The (Centers for Disease Control and Prevention) and the Surgeon General recommend that every home be tested," said Bennett. "The biggest problem is there's no financial aid available to homes that test high."

She said radon mitigation in the average home can cost about $2,000. If radon is coming up directly from the soil, a certified radon mitigator can install venting systems to direct the gas out of the house.

If radon is coming from a well, there are two types of devices that can make the water safer. Granulated activated carbon filters can capture the radon, and aerators can release radon from the water and carry it outside via an exhaust fan.

Either way, the resident will have to spend money, Bennett said.

"Filtering water is expensive," she said. "There's also the problem of how do you dispose of the radioactive filter."

And for people who don't own their homes, there may be little they can do about radon other than to relocate.

"Radon is not regulated in Georgia, and there is no central place to report," said Bennett. "A landlord is not obligated to test for radon, to reveal test results, or to fix it."

Bennett said she wishes she could do more to actually help people whose homes have radon problems.

"So far, about one in five homes in Hall is testing high," she said, meaning they exceed the threshold at which the EPA recommends mitigation should be done.

"But there is no safe level," she said. "It's radiation."