The short answer
City water is regulated under the Safe Drinking Water Act: your utility tests it and must send you an annual water quality report by July 1. Private well water isn't regulated by the federal government under that law or by most states, so the owner is responsible for testing it. In North Carolina, a new well is tested once when it's built; after that, regular testing is up to you.
Who is responsible for your water
| Feature | City (public) water | Private well |
|---|---|---|
| Who tests it | The utility, on a schedule set by regulators | You, the owner |
| Results published? | Yes, in an annual Consumer Confidence Report[source] | Only if you test and keep the results |
| Federal oversight | Safe Drinking Water Act | Not regulated under the Safe Drinking Water Act[source] |
| Required testing in NC | Ongoing, by the utility | One test when a new well is built[source] |
| Disinfectant | Added by the utility (chlorine or chloramine, by system) | None unless you add treatment |
| Typical issues | Taste and odor; home-specific lead from older plumbing | Iron, manganese, low pH, arsenic and bacteria, depending on the well |
EPA puts it plainly: private well owners are responsible for the safety of their own water, and private wells aren't regulated by the federal government under the Safe Drinking Water Act or by most state governments.[source] About 15 percent of the U.S. population relies on private wells.[source] Locally, Union County Environmental Health says about 25 percent of its population relies on groundwater for drinking water.[source]
How to tell which one you have
- Check for a water bill. If a city, town or county utility bills you for water, you're on public water. The name on the bill tells you which annual report is yours.
- Look for a well and pressure tank. A wellhead cap in the yard and a pressure tank in a garage, basement or crawl space usually mean a private well.
- No water bill, but a sewer or trash bill? You may still be on a well. Sewer and water service aren't always bundled.
- Ask or look it up. Our water lookup tool maps addresses to utility service areas, which come from EPA's boundary data.[source] Boundaries can miss edge cases, so the bill (or lack of one) is the final word.
City water: start from the utility's report
Every community water system must deliver an annual Consumer Confidence Report, and EPA says it must be sent each year by July 1.[source] That report is the best starting point for any treatment decision. For example, Charlotte Water's 2025 report shows zero violations, soft water at 32 mg/L of hardness, and free chlorine as the disinfectant.[source] Some nearby systems use chloramine instead, such as the City of Monroe, whose report says chlorine and ammonia are added to disinfect the water.[source]
With city water, treatment is usually about preference or something specific to your home, like chlorine taste or older plumbing that could add lead. Utility tests reflect the system, not your faucet. See our city water treatment options and the regional Charlotte-area water report.
Well water: start from a lab test
North Carolina requires every newly constructed private well to be tested by the state lab or a state-certified lab before it's used for drinking water.[source] After that, NC DHHS recommends testing for bacteria every year, for metals, nitrate, nitrite, lead and copper every two years, and for pesticides and volatile organic compounds every five years.[source] It also recommends testing after well repairs, flooding, or any change in taste, color or odor.[source]
Well results vary a lot by location. Among Union County private wells tested through the state lab, 19.46% of 5,154 were above the 10 µg/L arsenic standard.[source] Among Mecklenburg County tested wells, the share was 0.12% of 2,600.[source] Both describe tested wells, not every well, and neither tells you about yours. Only a certified-lab well test does.
Different treatment logic
- Step 1
City water
Read the utility report, decide whether anything bothers you (usually taste or odor), test at the tap only if there's a home-specific question like lead, then choose the smallest system that solves it. Often that's nothing, or a single drinking-water tap.
- Step 2
Well water
Test first with a certified lab. Treat what the results show, in the right order: sediment, iron and manganese, pH, then hardness, then drinking-water polish. Retest to confirm, and keep testing on schedule.
That's why our well water recommendations always start with a lab panel, while city recommendations start with the utility's report. If your home has both, like a well for irrigation and city water for the house, treat them as two separate questions. For a routine schedule, see how often to test well water in NC.