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Private wells

North Carolina well water: who's on a well and what to test for

An estimated 1,735,200 people in 810,900 homes, about 17.2% of North Carolina homes, above the national 14.6%. Estimates are from EPA's Water Source 2020 model.

People on private wells

1,735,200

Homes on wells

17.2%

Est. above arsenic limit

119,600

Alamance County: about 26% of homes on private wellsAlexander County: about 35% of homes on private wellsAlleghany County: about 75% of homes on private wellsAnson County: about 0% of homes on private wellsAshe County: about 84% of homes on private wellsAvery County: about 59% of homes on private wellsBeaufort County: about 0% of homes on private wellsBertie County: about 0% of homes on private wellsBladen County: about 14% of homes on private wellsBrunswick County: about 10% of homes on private wellsBuncombe County: about 16% of homes on private wellsBurke County: about 12% of homes on private wellsCabarrus County: about 10% of homes on private wellsCaldwell County: about 21% of homes on private wellsCamden County: about 0% of homes on private wellsCarteret County: about 21% of homes on private wellsCaswell County: about 90% of homes on private wellsCatawba County: about 18% of homes on private wellsChatham County: about 35% of homes on private wellsCherokee County: about 70% of homes on private wellsChowan County: about 0% of homes on private wellsClay County: about 86% of homes on private wellsCleveland County: about 2% of homes on private wellsColumbus County: about 48% of homes on private wellsCraven County: about 0% of homes on private wellsCumberland County: about 8% of homes on private wellsCurrituck County: about 6% of homes on private wellsDare County: about 0% of homes on private wellsDavidson County: about 1% of homes on private wellsDavie County: about 7% of homes on private wellsDuplin County: about 0% of homes on private wellsDurham County: about 3% of homes on private wellsEdgecombe County: about 0% of homes on private wellsForsyth County: about 2% of homes on private wellsFranklin County: about 29% of homes on private wellsGaston County: about 21% of homes on private wellsGates County: about 0% of homes on private wellsGraham County: about 77% of homes on private wellsGranville County: about 58% of homes on private wellsGreene County: about 0% of homes on private wellsGuilford County: about 12% of homes on private wellsHalifax County: about 0% of homes on private wellsHarnett County: about 1% of homes on private wellsHaywood County: about 36% of homes on private wellsHenderson County: about 23% of homes on private wellsHertford County: about 1% of homes on private wellsHoke County: about 0% of homes on private wellsHyde County: about 0% of homes on private wellsIredell County: about 28% of homes on private wellsJackson County: about 70% of homes on private wellsJohnston County: about 46% of homes on private wellsJones County: about 0% of homes on private wellsLee County: about 26% of homes on private wellsLenoir County: about 1% of homes on private wellsLincoln County: about 26% of homes on private wellsMcDowell County: about 64% of homes on private wellsMacon County: about 65% of homes on private wellsMadison County: about 74% of homes on private wellsMartin County: about 0% of homes on private wellsMecklenburg County: about 1% of homes on private wellsMitchell County: about 66% of homes on private wellsMontgomery County: about 22% of homes on private wellsMoore County: about 16% of homes on private wellsNash County: about 39% of homes on private wellsNew Hanover County: about 7% of homes on private wellsNorthampton County: about 1% of homes on private wellsOnslow County: about 0% of homes on private wellsOrange County: about 26% of homes on private wellsPamlico County: about 0% of homes on private wellsPasquotank County: about 0% of homes on private wellsPender County: about 46% of homes on private wellsPerquimans County: about 1% of homes on private wellsPerson County: about 63% of homes on private wellsPitt County: about 0% of homes on private wellsPolk County: about 64% of homes on private wellsRandolph County: about 44% of homes on private wellsRichmond County: about 7% of homes on private wellsRobeson County: about 0% of homes on private wellsRockingham County: about 38% of homes on private wellsRowan County: about 47% of homes on private wellsRutherford County: about 38% of homes on private wellsSampson County: about 72% of homes on private wellsScotland County: about 0% of homes on private wellsStanly County: about 25% of homes on private wellsStokes County: about 53% of homes on private wellsSurry County: about 65% of homes on private wellsSwain County: about 68% of homes on private wellsTransylvania County: about 58% of homes on private wellsTyrrell County: about 3% of homes on private wellsUnion County: about 11% of homes on private wellsVance County: about 46% of homes on private wellsWake County: about 9% of homes on private wellsWarren County: about 0% of homes on private wellsWashington County: about 0% of homes on private wellsWatauga County: about 53% of homes on private wellsWayne County: about 0% of homes on private wellsWilkes County: about 39% of homes on private wellsWilson County: about 25% of homes on private wellsYadkin County: about 75% of homes on private wellsYancey County: about 80% of homes on private wells
Homes on private wellsUnder 5%5-15%15-30%30-50%50% or more

Every North Carolina county

Sorted by people on private wells. Arsenic and nitrate are modeled for typical wells in the county, not measured at yours; depth is the median of domestic well records.

Wake County106,4009%2.2%1.0n/a
Johnston County98,60046%1.6%0.5n/a
Rowan County68,70047%3.0%0.9n/a
Guilford County65,60012%1.8%0.8200 ft
Randolph County64,20044%1.4%0.5n/a
Iredell County51,30028%1.9%1.2n/a
Gaston County47,40021%1.3%1.2n/a
Surry County47,10065%1.6%1.0n/a
Alamance County44,40026%2.0%0.9n/a
Buncombe County43,80016%1.6%0.7n/a
Sampson County43,10072%2.5%0.1n/a
Nash County39,30039%1.3%0.9n/a
Orange County37,20026%1.9%0.3185 ft
Rockingham County36,00038%2.4%0.5n/a
Granville County33,30058%2.5%0.3n/a
Pender County29,10046%1.7%0.1n/a
Catawba County28,20018%1.5%1.3n/a
McDowell County27,90064%1.5%0.2n/a
Yadkin County27,80075%2.5%0.8n/a
Cumberland County27,5008%2.3%0.6n/a
Henderson County26,70023%1.2%1.0n/a
Watauga County26,50053%1.2%0.2n/a
Chatham County26,40035%1.9%0.3n/a
Jackson County26,00070%1.2%0.1n/a
Person County24,90063%1.6%0.4n/a
Macon County24,60065%1.3%0.2n/a
Wilkes County24,30039%1.8%0.6n/a
Rutherford County23,90038%1.6%1.0n/a
Lincoln County23,80026%1.4%1.6n/a
Columbus County23,80048%1.8%0.0n/a
Haywood County23,10036%1.4%0.3n/a
Stokes County22,90053%2.1%0.3n/a
Cabarrus County22,50010%2.5%1.1n/a
Union County22,50011%2.0%0.8n/a
Ashe County21,50084%1.2%0.4n/a
Wilson County20,60025%1.5%0.9n/a
Carteret County20,00021%4.8%0.0n/a
Brunswick County19,60010%2.8%0.0n/a
Vance County19,50046%1.9%0.5n/a
Caswell County19,40090%1.8%0.1n/a
Cherokee County19,20070%1.4%0.1n/a
Transylvania County18,50058%0.8%0.3n/a
Franklin County18,20029%1.8%0.5n/a
New Hanover County17,7007%2.3%0.0n/a
Lee County16,60026%2.1%0.6n/a
Moore County15,80016%1.4%0.5n/a
Caldwell County15,80021%1.4%0.6n/a
Madison County15,20074%1.8%0.3n/a
Stanly County15,10025%2.1%0.8n/a
Yancey County14,80080%2.4%0.1n/a
Polk County12,60064%1.1%0.3n/a
Alexander County12,50035%1.5%0.8n/a
Avery County10,90059%1.8%0.2n/a
Durham County10,7003%3.3%0.3n/a
Burke County9,60012%1.7%0.6n/a
Clay County9,40086%1.2%0.2n/a
Mitchell County9,20066%3.6%0.2n/a
Swain County9,10068%1.4%0.1n/a
Alleghany County7,90075%1.3%0.8n/a
Mecklenburg County7,6001%1.6%1.3n/a
Montgomery County7,00022%1.4%0.2n/a
Graham County6,10077%1.3%0.1n/a
Forsyth County5,9002%1.8%0.6n/a
Bladen County4,30014%2.1%0.0n/a
Richmond County3,1007%1.4%0.5n/a
Davie County3,0007%3.4%0.8n/a
Cleveland County2,3002%1.7%1.8n/a
Davidson County1,7001%2.3%0.8n/a
Currituck County1,6006%3.1%0.1n/a
Harnett County1,2001%1.6%0.4n/a
Lenoir County9001%5.2%0.2n/a
Pitt County8600%2.5%0.3n/a
Onslow County2900%2.1%0.1n/a
Northampton County2301%1.8%0.1n/a
Tyrrell County1403%2.6%0.0118 ft
Hertford County1301%1.4%0.0n/a
Wayne County1200%2.0%0.6n/a
Perquimans County701%1.5%0.1n/a
Scotland County500%1.5%0.5n/a
Bertie County500%2.4%0.1n/a
Martin County500%3.9%0.4n/a
Hyde County300%2.9%0.0125 ft
Hoke County100%1.4%0.5n/a
Anson County100%3.2%0.3n/a
Craven County100%3.2%0.268 ft
Dare County00%4.7%0.0n/a
Beaufort County00%3.3%0.1185 ft
Camden County00%1.9%0.1n/a
Chowan County00%3.8%0.230 ft
Duplin County00%2.1%0.3n/a
Edgecombe County00%1.6%0.6n/a
Gates County00%1.8%0.1n/a
Greene County00%2.9%0.6n/a
Halifax County00%1.4%0.6n/a
Jones County00%1.6%0.0n/a
Pamlico County00%3.3%0.0170 ft
Pasquotank County00%1.7%0.1n/a
Robeson County00%1.5%0.2n/a
Warren County00%1.6%0.3n/a
Washington County00%2.1%0.135 ft

Shading: red is among the highest counties nationally, amber the middle, green the lower range. Click a column to sort.

Most well users above the arsenic limit

Test first, then treat what the test finds

We may earn a commission from links below, at no cost to you. Picks follow the testing order, not who pays. How we make money.

1. Certified lab well test

Start here, every year

A mail-in kit analyzed by a certified lab measures bacteria, nitrate, arsenic, metals and more. Test strips cannot measure arsenic or uranium reliably.

Mail-in certified lab well water test

Mid-range
See today's price on Amazon

2. Sediment pre-filter

Sand, silt or cloudy water

A 5-micron cartridge after the pressure tank catches sand, silt and rust before they reach fixtures or other filters. Cartridges are cheap and swap every few months.

5-micron whole-house sediment filter

Budget
See today's price on Amazon

3. Iron and sulfur filter

Orange stains or rotten-egg smell

Air-injection or oxidizing-media filters remove orange staining and rotten-egg smell. Size one from a lab result for iron, manganese and hydrogen sulfide.

Air-injection iron and sulfur filter

Premium
See today's price on Amazon

4. UV disinfection system

Coliform bacteria in a test

Inactivates bacteria and viruses; usually for private wells or after boil notices.

12 GPM whole-house UV purifier

Premium
See today's price on Amazon

5. Under-sink reverse osmosis

Arsenic, nitrate or uranium in a test

The most thorough option for drinking water: PFAS, lead, nitrate, arsenic and more. Look for NSF/ANSI 58.

Waterdrop G3P600 tankless RO

$539.00
Buy at Waterdrop

Price at Waterdrop, checked Oct 5, 2026or compare on Amazon

iSpring RCC7AK reverse osmosis

Mid-range
See today's price on Amazon

6. Whole-house well filter

Several problems at once

Multi-stage sediment and carbon for every tap. Add UV if bacteria shows up, and choose stages from your lab results, not a guess.

Waterdrop WHF21 2-stage whole-house filter

Mid-range
See today's price on Amazon
Get free well water treatment quotes

Questions

Which North Carolina counties rely most on wells?+

By share of homes: Caswell County (90%), Clay County (86%), Ashe County (84%), Yancey County (80%), Graham County (77%). By number of people: Wake County (106,400), Johnston County (98,600), Rowan County (68,700).

Is arsenic a problem in North Carolina wells?+

USGS estimates about 119,600 North Carolina well users have water above the 10 microgram per liter arsenic limit that applies to public systems, the largest numbers in Mecklenburg County, Wake County, Guilford County. Arsenic has no taste or smell, so only a lab test finds it.

Do I have to test my well when I sell a house in North Carolina?+

We could not confirm a statewide rule for North Carolina. Check with your county health department. Buyers can still make a lab test a condition of the offer.

How often should I test my well?+

No federal law covers private wells. EPA's drinking water limits apply to public water systems, so testing and treating a private well is up to the owner. EPA and CDC recommend testing at least once a year for coliform bacteria, nitrate, pH and total dissolved solids, and testing for arsenic, uranium, radon and other local concerns based on where you live.

Well-user counts, arsenic and nitrate figures are each a modeled estimate built from national datasets, not a count of tested wells, and well depths summarize drilling records rather than every well. Your own well can be very different from the county average, which is why the only answer for your home is a lab test. Sources: EPA Office of Research and Development, Water Source 2020 (private well estimates by census block); CDC Environmental Public Health Tracking, Well Water Index (from USGS nitrate and arsenic models); USGS, county-level domestic well population with arsenic above 10 micrograms per liter (Ayotte and others, 2017); USGS Synthesized Domestic Well Database for the Conterminous United States (SynDWell-US), McCarthy and others, 2025 (depth, where a county has 30+ usable records).