Over 2.4 million people in North Carolina drink from private wells[6]. That is roughly 24% of the state.
NC requires testing only when your well is first drilled. After that, you are on your own[7]. Here is what every NC well owner needs to know.
Quick Answer
Test for bacteriaColiform BacteriaA group of bacteria used as indicators of potential contamination. Total coliform presence suggests a pathway for pathogens to enter your well.EPA MCL: 0 (no coliform should be present)Learn more → (contamination indicators) and nitratesNitratesCompounds that enter groundwater from fertilizers, septic systems, and animal waste. Especially dangerous for infants under 6 months (blue baby syndrome).EPA MCL: 10 mg/L (ppm)Learn more → (fertilizer compounds) every year. Also test for ironIronA naturally occurring mineral found in groundwater. Iron causes orange/rust staining on fixtures and laundry and gives water a metallic taste.EPA Secondary MCL: 0.3 mg/L (ppm)Learn more → (staining mineral), pH, hardnessHardness (Calcium Carbonate)The concentration of dissolved calcium and magnesium in water. Hard water causes scale buildup in pipes, water heaters, and fixtures.No EPA standard. Soft: <1 gpg. Moderate: 1-7 gpg. Hard: 7-10.5 gpg. Very Hard: >10.5 gpg.Learn more → (dissolved calcium), and manganeseManganeseA mineral that causes black or brown staining and can affect the taste of water. Often found alongside iron in well water.EPA Secondary MCL: 0.05 mg/L (ppm). EPA Health Advisory: 0.3 mg/LLearn more → (black staining mineral). In the Piedmont region, add arsenicArsenicA toxic element found naturally in bedrock that dissolves into groundwater. Odorless and tasteless, making testing the only way to detect it.EPA MCL: 10 ppb (0.01 mg/L)Learn more → (toxic bedrock element).
NC Well Water Testing Requirements
North Carolina requires a water test only when a new well is constructed[7]. The builder must test for bacteria and a short list of contaminants before you move in.
After that? No state requirement to ever test again. The NC DHHS recommends annual testing, but it is not mandatory[1].
Bottom line: If you have not tested since your well was drilled, test now.
Have your test results? Get a plain-English diagnosis.
Analyze My Water TestMost Common Contaminants in NC Wells
| Contaminant | Where in NC | How Common | Learn More |
|---|---|---|---|
| Iron | Statewide, especially Piedmont | Very common | Iron guide |
| Manganese | Piedmont, Mountains | Common | Manganese guide |
| Low pH (acidic) | Mountains, upper Piedmont | Common | Acidic water guide |
| Bacteria | Statewide (shallow wells) | Moderate | Bacteria guide |
| Arsenic | Piedmont (slate belt) | Localized but serious | Arsenic guide |
| Nitrates | Coastal Plain (farm areas) | Moderate | Nitrates guide |
| Hard water | Piedmont, Coastal Plain | Common | Hard water guide |
NC Well Water by Region
Mountains (Western NC)
Granite and metamorphic rock. Expect low pH (acidic water), iron, and manganese. Arsenic is possible but less common than the Piedmont. Wells are often shallow[3].
Priority tests: pH, iron, manganese, bacteria.
Piedmont (Central NC — Raleigh, Charlotte, Greensboro)
The most geologically complex region. Iron and manganese are widespread. The Carolina Slate Belt (running from the Virginia border through central NC) has naturally elevated arsenic[8].
Priority tests: Arsenic, iron, manganese, pH, bacteria.
Coastal Plain (Eastern NC)
Sandy soils. Agricultural runoff drives nitrate contamination, especially near hog and poultry farms. Iron is common. Water is often softer than the Piedmont[2].
Priority tests: Nitrates, bacteria, iron.
Where to Get Your NC Well Water Tested
- NC State Laboratory of Public Health (Raleigh). Offers bacteria and chemistry panels. Contact your county health department to arrange sample collection[5].
- County health departments. Most NC counties offer well water testing or can refer you to the state lab. Call your local health department.
- Private certified labs. Search for NC-certified labs through the NC DHHS Division of Public Health website.
- Mail-in services. Tap Score and other national services accept samples from NC. Full panels cost $100–$300.
Cost: The state lab charges $5–$15 per test for basic panels. Private labs charge $50–$200 for comprehensive panels.
What to Do Next
Haven't tested? Contact your county health department or order a mail-in test. At minimum: bacteria, nitrates, pH, iron, manganese. Add arsenic if you are in the Piedmont.
Have results? Enter them in our Water Test Interpreter for a personalized treatment plan.
New to wells? Read our New Homeowner Guide and How to Read a Water Test.
Frequently Asked Questions
Does NC require well water testing?
Only when a new well is drilled[7]. After that, no mandate. Annual testing is recommended but not required.
What contaminants are common in NC?
Iron, manganese, low pH, bacteria statewide. Arsenic in the Piedmont slate belt. Nitrates in eastern agricultural areas[2].
Where do I get tested in NC?
NC State Lab (via your county health department, $5–$15), private certified labs ($50–$200), or mail-in services like Tap Score[5].
References
- NC DHHS. "Private Well Water Testing Guide." Division of Public Health, 2023. https://www.ncdhhs.gov
- NC DEQ. "Groundwater Quality in North Carolina." Division of Water Resources, 2023. https://www.deq.nc.gov
- U.S. Geological Survey. "Groundwater Quality in North Carolina." NAWQA, 2023. https://www.usgs.gov/mission-areas/water-resources
- NC Cooperative Extension. "Drinking Water Quality for Private Wells." NC State University, 2023.
- NC DHHS. "State Laboratory of Public Health: Water Testing Services." 2024. https://slph.ncdhhs.gov
- U.S. Census Bureau. "Households Using Wells by State." American Housing Survey, 2021.
- NC General Statutes. "Well Construction Standards: 15A NCAC 02C." 2024.
- NC DHHS. "Arsenic and Private Wells in North Carolina." 2023.