North Carolina well water by county: arsenic and nitrate
Modelled arsenic and nitrate for private-well users in every North Carolina county, what to test for, and where to find a certified lab. Private wells aren’t covered by the Safe Drinking Water Act.
All 100 counties
- Wake CountyWell users 61,600Arsenic about 2 in 100Nitrate 1.0 mg/L
- Guilford CountyWell users 59,700Arsenic about 2 in 100Nitrate 0.8 mg/L
- Rowan CountyWell users 52,600Arsenic about 3 in 100Nitrate 0.9 mg/L
- Johnston CountyWell users 51,500Arsenic about 2 in 100Nitrate 0.5 mg/L
- Randolph CountyWell users 50,900Arsenic about 1 in 100Nitrate 0.5 mg/L
- Gaston CountyWell users 46,200Arsenic about 1 in 100Nitrate 1.2 mg/L
- Surry CountyWell users 45,900Arsenic about 2 in 100Nitrate 1.0 mg/L
- Sampson CountyWell users 45,800Arsenic about 3 in 100Nitrate 0.1 mg/L
- Catawba CountyWell users 43,900Arsenic about 2 in 100Nitrate 1.3 mg/L
- Wayne CountyWell users 42,000Arsenic about 2 in 100Nitrate 0.6 mg/L
- Rockingham CountyWell users 39,900Arsenic about 2 in 100Nitrate 0.5 mg/L
- Columbus CountyWell users 39,900Arsenic about 2 in 100Nitrate 0.0 mg/L
- Mecklenburg CountyWell users 39,800Arsenic about 2 in 100Nitrate 1.3 mg/L
- Cumberland CountyWell users 39,600Arsenic about 2 in 100Nitrate 0.6 mg/L
- Union CountyWell users 38,900Arsenic about 2 in 100Nitrate 0.8 mg/L
- Brunswick CountyWell users 36,700Arsenic about 3 in 100Nitrate 0.0 mg/L
- Iredell CountyWell users 36,600Arsenic about 2 in 100Nitrate 1.2 mg/L
- Harnett CountyWell users 36,200Arsenic about 2 in 100Nitrate 0.4 mg/L
- Nash CountyWell users 35,300Arsenic about 1 in 100Nitrate 0.9 mg/L
- Alamance CountyWell users 35,100Arsenic about 2 in 100Nitrate 0.9 mg/L
- Robeson CountyWell users 34,800Arsenic about 2 in 100Nitrate 0.2 mg/L
- Duplin CountyWell users 34,100Arsenic about 2 in 100Nitrate 0.4 mg/L
- Buncombe CountyWell users 33,600Arsenic about 2 in 100Nitrate 0.7 mg/L
- Cleveland CountyWell users 33,100Arsenic about 2 in 100Nitrate 1.8 mg/L
- Forsyth CountyWell users 32,000Arsenic about 2 in 100Nitrate 0.6 mg/L
- Moore CountyWell users 30,900Arsenic about 1 in 100Nitrate 0.5 mg/L
- Pender CountyWell users 30,800Arsenic about 2 in 100Nitrate 0.0 mg/L
- Rutherford CountyWell users 30,100Arsenic about 2 in 100Nitrate 1.0 mg/L
- Orange CountyWell users 29,100Arsenic about 2 in 100Nitrate 0.3 mg/L
- Franklin CountyWell users 28,200Arsenic about 2 in 100Nitrate 0.5 mg/L
- Chatham CountyWell users 27,400Arsenic about 2 in 100Nitrate 0.2 mg/L
- Durham CountyWell users 27,400Arsenic about 3 in 100Nitrate 0.3 mg/L
- Lincoln CountyWell users 26,600Arsenic about 1 in 100Nitrate 1.6 mg/L
- Wilkes CountyWell users 26,300Arsenic about 2 in 100Nitrate 0.6 mg/L
- Henderson CountyWell users 26,100Arsenic about 1 in 100Nitrate 1.0 mg/L
- Beaufort CountyWell users 25,600Arsenic about 3 in 100Nitrate 0.0 mg/L
- Stokes CountyWell users 25,500Arsenic about 2 in 100Nitrate 0.4 mg/L
- Granville CountyWell users 25,500Arsenic about 3 in 100Nitrate 0.3 mg/L
- Stanly CountyWell users 25,400Arsenic about 2 in 100Nitrate 0.8 mg/L
- Cabarrus CountyWell users 24,800Arsenic about 2 in 100Nitrate 1.1 mg/L
- Carteret CountyWell users 24,700Arsenic about 5 in 100Nitrate 0.0 mg/L
- McDowell CountyWell users 24,400Arsenic about 1 in 100Nitrate 0.2 mg/L
- Burke CountyWell users 24,100Arsenic about 2 in 100Nitrate 0.6 mg/L
- Yadkin CountyWell users 23,900Arsenic about 2 in 100Nitrate 0.8 mg/L
- New Hanover CountyWell users 23,100Arsenic about 2 in 100Nitrate 0.0 mg/L
- Person CountyWell users 22,400Arsenic about 2 in 100Nitrate 0.4 mg/L
- Bladen CountyWell users 22,200Arsenic about 2 in 100Nitrate 0.0 mg/L
- Caldwell CountyWell users 20,900Arsenic about 1 in 100Nitrate 0.6 mg/L
- Wilson CountyWell users 20,300Arsenic about 2 in 100Nitrate 0.9 mg/L
- Caswell CountyWell users 19,400Arsenic about 2 in 100Nitrate 0.1 mg/L
- Edgecombe CountyWell users 18,700Arsenic about 2 in 100Nitrate 0.6 mg/L
- Vance CountyWell users 18,300Arsenic about 2 in 100Nitrate 0.5 mg/L
- Halifax CountyWell users 17,800Arsenic about 1 in 100Nitrate 0.6 mg/L
- Craven CountyWell users 17,000Arsenic about 3 in 100Nitrate 0.2 mg/L
- Scotland CountyWell users 16,500Arsenic about 2 in 100Nitrate 0.5 mg/L
- Lee CountyWell users 16,100Arsenic about 2 in 100Nitrate 0.6 mg/L
- Davidson CountyWell users 15,900Arsenic about 2 in 100Nitrate 0.8 mg/L
- Pitt CountyWell users 15,800Arsenic about 2 in 100Nitrate 0.3 mg/L
- Warren CountyWell users 14,900Arsenic about 2 in 100Nitrate 0.3 mg/L
- Alexander CountyWell users 14,600Arsenic about 1 in 100Nitrate 0.9 mg/L
- Macon CountyWell users 14,500Arsenic about 1 in 100Nitrate 0.2 mg/L
- Haywood CountyWell users 14,400Arsenic about 1 in 100Nitrate 0.3 mg/L
- Hoke CountyWell users 14,300Arsenic about 1 in 100Nitrate 0.5 mg/L
- Transylvania CountyWell users 13,800Arsenic about 1 in 100Nitrate 0.3 mg/L
- Watauga CountyWell users 13,400Arsenic about 1 in 100Nitrate 0.2 mg/L
- Jackson CountyWell users 13,300Arsenic about 1 in 100Nitrate 0.1 mg/L
- Bertie CountyWell users 12,900Arsenic about 2 in 100Nitrate 0.1 mg/L
- Martin CountyWell users 12,700Arsenic about 4 in 100Nitrate 0.4 mg/L
- Onslow CountyWell users 12,500Arsenic about 2 in 100Nitrate 0.1 mg/L
- Davie CountyWell users 12,400Arsenic about 3 in 100Nitrate 0.8 mg/L
- Richmond CountyWell users 12,200Arsenic about 1 in 100Nitrate 0.5 mg/L
- Hertford CountyWell users 11,600Arsenic about 1 in 100Nitrate 0.0 mg/L
- Montgomery CountyWell users 11,400Arsenic about 1 in 100Nitrate 0.2 mg/L
- Polk CountyWell users 11,400Arsenic about 1 in 100Nitrate 0.3 mg/L
- Ashe CountyWell users 11,100Arsenic about 1 in 100Nitrate 0.4 mg/L
- Cherokee CountyWell users 10,500Arsenic about 1 in 100Nitrate 0.1 mg/L
- Currituck CountyWell users 10,200Arsenic about 3 in 100Nitrate 0.1 mg/L
- Northampton CountyWell users 9,900Arsenic about 2 in 100Nitrate 0.1 mg/L
- Lenoir CountyWell users 8,800Arsenic about 5 in 100Nitrate 0.2 mg/L
- Anson CountyWell users 8,700Arsenic about 3 in 100Nitrate 0.3 mg/L
- Madison CountyWell users 8,200Arsenic about 2 in 100Nitrate 0.3 mg/L
- Camden CountyWell users 6,900Arsenic about 2 in 100Nitrate 0.0 mg/L
- Avery CountyWell users 6,900Arsenic about 2 in 100Nitrate 0.2 mg/L
- Yancey CountyWell users 6,100Arsenic about 2 in 100Nitrate 0.1 mg/L
- Clay CountyWell users 5,900Arsenic about 1 in 100Nitrate 0.2 mg/L
- Alleghany CountyWell users 5,400Arsenic about 1 in 100Nitrate 0.8 mg/L
- Dare CountyWell users 5,200Arsenic about 5 in 100Nitrate 0.0 mg/L
- Mitchell CountyWell users 4,500Arsenic about 4 in 100Nitrate 0.2 mg/L
- Washington CountyWell users 4,500Arsenic about 2 in 100Nitrate 0.1 mg/L
- Swain CountyWell users 3,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Gates CountyWell users 2,700Arsenic about 2 in 100Nitrate 0.1 mg/L
- Jones CountyWell users 2,500Arsenic about 2 in 100Nitrate 0.0 mg/L
- Hyde CountyWell users 2,100Arsenic about 3 in 100Nitrate 0.0 mg/L
- Graham CountyWell users 2,000Arsenic about 1 in 100Nitrate 0.1 mg/L
- Pamlico CountyWell users 1,900Arsenic about 3 in 100Nitrate 0.0 mg/L
- Greene CountyWell users 1,900Arsenic about 3 in 100Nitrate 0.6 mg/L
- Tyrrell CountyWell users 1,400Arsenic about 3 in 100Nitrate 0.0 mg/L
- Pasquotank CountyWell users 1,100Arsenic about 2 in 100Nitrate 0.1 mg/L
- Perquimans CountyWell users 1,000Arsenic about 1 in 100Nitrate 0.1 mg/L
- Chowan CountyWell users 670Arsenic about 4 in 100Nitrate 0.2 mg/L
Each mark = 1 in 100 well users the model places above 10 µg/L arsenic (scale 0–10)10 mg/L nitrate: the federal limit (MCL) for public systems
- These figures describe the area, not your well. Only a lab test shows what’s in your water.
- CDC says the Well Water Index figures “do not describe risk to individual wells.” (CDC Tracking Network)
- The arsenic model is better at spotting low-arsenic areas than at confirming high ones.
- Well-user counts are 2010 USGS estimates; tract values are averages over each census tract.
- Total coliform bacteriaEvery year
- NitrateEvery year
- Total dissolved solidsEvery year
- pHEvery year
- ArsenicAsk your local health department
EPA: Private Drinking Water Wells · CDC: Guidelines for Testing Well Water
Use a state-certified lab
North Carolina State Laboratory of Public Health lists the laboratories certified to test drinking water in North Carolina.
Screening tells you if something is worth a closer look
A lab result is the number you can act on.
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Lab-certified results
ETR Labs Basic Water Quality Test Kit
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
- Analyzed by Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638
- Turnaround: 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Screening: quick check, not lab-grade
Watersafe Drinking Water Test Kit
Silver Lake Research
Lead, bacteria, nitrate, copper, iron, chlorine, hardness and pH
- Turnaround: Minutes; the bacteria test can take up to 48 hours
What it can't tell you: Each test gives a yes/no or a rough range, not a lab number, and it cannot detect PFAS or arsenic.
A mail-in kit’s lab is accredited (ISO/IEC 17025) but may not be certified by your state. For a home sale, a loan, or a health-department follow-up, use a state-certified lab.
North Carolina well water
Sources: CDC Well Water Index (2024) · USGS arsenic and nitrate models · USGS domestic well populations · EPA and CDC testing guidance. Data last updated 2026-10-08. All sources →
How many people use private wells in North Carolina?
About 2.2 million people across 100 North Carolina counties, by the USGS 2010 estimate. USGS models place about 42,600 of them in areas where wells are likely to be above the 10 µg/L arsenic limit. These are area estimates, not well results.
Are private wells regulated in North Carolina?
The quality and safety of drinking water from private domestic wells are not regulated by the Federal Government under the Safe Drinking Water Act nor by most state governments and laws. (EPA) Testing and treatment are the owner's responsibility.
Where can I get my well tested in North Carolina?
North Carolina State Laboratory of Public Health keeps the list of laboratories certified to test drinking water in North Carolina. Only use laboratories that are certified to do drinking water testing. (EPA)