North Carolina has one of the larger private-well populations in the country, spanning the state’s coastal plain, Piedmont, and mountain regions — each with distinct geology and distinct well-water concerns. Private wells are not regulated under the federal Safe Drinking Water Act, and testing is the well owner’s responsibility.
Why test
None of the common contaminants below have a reliable taste, odor, or color at concerning levels, so a well can seem completely normal while still testing positive.
What to test for
A baseline panel for a North Carolina well should include:
- Total coliform bacteria and E. coli — a standard first check for well vulnerability to contamination.
- Nitrate — a documented concern in the state’s agricultural eastern coastal plain, tied to fertilizer and manure application; especially important for households preparing infant formula with well water.
- Arsenic — naturally occurring arsenic has been documented in some North Carolina groundwater.
- Lead — mainly relevant to household plumbing rather than the source water.
- Radon — Piedmont and mountain-region wells drilled into granite or similar bedrock have documented naturally elevated radon in some areas; ask your lab whether this is a relevant addition for your county.
- Hexavalent chromium — some North Carolina areas near coal ash storage sites have drawn attention to this contaminant specifically; if your property is near a documented site, ask your lab about testing for it directly rather than relying on a standard baseline panel alone.
How often to test
EPA guidance recommends testing private wells for bacteria and nitrate at least annually, and again any time water quality changes noticeably, after well or plumbing work, or after flooding.
Where to find a certified lab
Drinking-water analyses in North Carolina must be performed by a laboratory certified by the North Carolina State Laboratory of Public Health; the NC Department of Environmental Quality’s Drinking Water Laboratories page (see the source link above) provides guidance and lab information.
After you test
If a result comes back above a health-based guideline, see our filter guides for which technologies are certified to remove the specific contaminant found.