Wake County officials are urging private well owners in the eastern half of the county to test their water.
County tests have uncovered unsafe levels of uranium, radon and radium in the water of some areas of eastern Wake County. Not all wells are impacted, but the county is urging private well owners to test their water to determine their vulnerability.
Those substances are naturally occurring, but heightened exposure can cause significant health problems, including kidney toxicity and cancer, according to the county.
"The rock in eastern Wake County naturally has higher levels of uranium than other rock in Wake County," said Evan Kane, the county's groundwater manager. "So that natural condition is what leads to the contaminants showing up in ground water. So this is not a result of human activities."
The county identified 15,000 homes in eastern Wake County believed to be served by private wells that could be affected. Sample tests showed that about one in five wells are affected and Kane said that ratio is likely to hold consistent throughout the affected area, meaning about 3,000 private wells could be contaminated.
Even if well owners find contaminated water, Kane said there are solutions.
"But the key thing is that all of these contaminants are treatable. There are readily available fixes for them," he said.
Homes that receive water from a municipal or community well supply don't need to worry about contaminated water because those systems are regularly checked to adhere to maintain compliance with the Safe Drinking Water Act. In short, homeowners that pay a monthly water bill need not be concerned about contaminated water, said Kane.
An estimated 150,000 people in the county, or about 15 percent of the population, drink water from a private well. Those in the western half of the county don't need to be especially concerned about this warning, though Kane said he advises any private well owner to regularly check water quality.
Private well owners are responsible for the maintenance of their wells, and must cover the cost for testing from a private lab. Those in the affected areas with incomes below the federal poverty level - $25,750 for a family of four – can request a comprehensive test from the county for $73. Those with incomes up to two-and-a-half times the poverty line can get tests for $182.50.
Correction: An earlier version of this story incorrectly stated the price of private well testing by the county for low income households. It's $73 for people at the poverty line and $182.50 for those up to 2.5 times the poverty line.