Radon in North Carolina well water

In North Carolina, radon was detected in 99% of 372 tested private well samples.

Radon is a radioactive gas released from bedrock into well water. It escapes into household air during showers and washing, where inhaling it raises lung cancer risk. EPA has no enforceable water MCL; New Hampshire recommends treatment above 2,000 pCi/L, and many states use 4,000 pCi/L.

Check your radon number

Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.

Getting it fixed

Book a free in-home water test with a licensed local company, or see the treatment guide for what removes radon.

By county, from individual samples

Public monitoring samples against the EPA limit; counties with at least 30 samples.

County	Samples	Detected	Above EPA limit	Median	Highest
Iredell	37	100%	no limit	270	2,880 pCi/L
Orange	53	100%	no limit	400	4,460 pCi/L
Wake	31	100%	no limit	2,990	13,800 pCi/L
Guilford	70	96%	no limit	745	6,300 pCi/L

Sources

Individual samples from the USGS Water Quality Portal and state monitoring, summarized per geography. radon counts and shares are listed on each county and town page with their sources.