The most serious well contaminants in North Carolina have no taste, smell or color. Here's where they occur, the limits, and what removes them.
Updated
Quick answer
Arsenic shows up most in the Carolina Slate Belt, which runs from Union County northeast to Person County. Uranium, radium and radon concentrate in eastern Wake County, where Wake County expects one in five wells to have unsafe levels. None of them can be tasted or smelled, so a lab test is the only way to know. Reverse osmosis removes arsenic and uranium from drinking water.
Iron stains and sulfur smells announce themselves. Arsenic, uranium, radium and radon don't. Water that looks and tastes perfect can carry any of them, and the only way to know is a lab test.
All four come from the rock under your home, not from pollution. Where you live in North Carolina largely decides whether they are a concern.
Arsenic is a known human carcinogen, according to the EPA. The drinking water standard is 10 micrograms per liter, and North Carolina uses the same limit. Long-term exposure is linked to skin changes, nerve damage, and liver and kidney damage.
In North Carolina, arsenic turns up most in the Carolina Slate Belt, a band of old volcanic rock that runs from Union County northeast to Person County. NC DHHS reports that Alexander, Anson, Dare, Montgomery, Stanly and Union counties typically have higher occurrences. Statewide, 2.26% of wells sampled in 2018–2019 exceeded the standard, and some areas had detectable arsenic in 5% or more of wells.
The rock under eastern Wake County is naturally rich in uranium. As it breaks down, uranium, radium and radon dissolve into groundwater. Wake County expects one in five wells in eastern Wake to have unsafe levels of these contaminants.
Over the long term, drinking water with too much uranium or radium, or drinking and bathing in water with too much radon, raises the risk of certain cancers. Uranium can also damage the kidneys. The EPA limit for uranium is 30 micrograms per liter.
| Contaminant | Effective treatment | Our system |
|---|---|---|
| Arsenic | Reverse osmosis, adsorptive media or ion exchange, often after an oxidizing pre-filter | 7-Stage RO, with an oxidizing filter ahead of it when needed |
| Uranium | Reverse osmosis or anion exchange | 7-Stage RO or 5-Stage RO |
| Radium | Cation exchange (softening) or reverse osmosis | Water softener plus RO |
| Radon in water | Aeration or point-of-entry carbon | Specialist system; we assess it during your test |
NC DHHS notes that arsenic comes in two forms, and the more toxic form is harder to remove. An oxidizing pre-filter converts it to the form RO and other systems remove reliably. That is why we design arsenic treatment around your full test results, not a single number.
Test for it. Arsenic has no taste, smell or color. NC DHHS recommends testing for heavy metals, including arsenic, every two years through your county health department or a certified lab.
A standard softener removes radium but not uranium. Reverse osmosis removes uranium from drinking water.
In eastern Wake County, yes. Wake County recommends a radionuclide test covering uranium, gross alpha and beta, and radon in water.
For drinking and cooking water, RO is one of the treatments NC DHHS lists for arsenic. Depending on your water, we may add an oxidizing pre-filter so the RO works on every form of arsenic.
Bring us your lab results or start with our free on-site test. We design the system around what your water actually has.