Tested Water

Nitrate in Virginia well water, by county

Nitrate is worth checking in 4 of the 14 Virginia counties with 10 or more tested wells, and rare in the rest. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

How Virginia compares with the rest of the country

Across Virginia, about 1 in 28 tested wells had nitrate over the EPA limit of 10 mg/L (16 of 452). Across all tested wells in the US it's about 1 in 12. That's less often than in the country as a whole. Counties still differ, so check yours below.

Why it matters: It's dangerous for babies under 6 months, because it keeps their blood from carrying enough oxygen.

Nitrate soaks down into groundwater from fertilizer, manure and septic systems.

Nitrate in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA limit of 10 mg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Caroline County 49
14% 7 of 49
Worth checking
Rockingham County 15
13% 2 of 15
Worth checking
Prince William County 13
8% 1 of 13
Worth checking
Northampton County 30
7% 2 of 30
Worth checking
Accomack County 42
5% 2 of 42
Rare
Virginia Beach city 23
4% 1 of 23
Rare
Culpeper County 22
0% 0 of 22
Rare
Isle of Wight County 16
0% 0 of 16
Rare
King William County 16
0% 0 of 16
Rare
Chesapeake city 14
0% 0 of 14
Rare
Suffolk city 14
0% 0 of 14
Rare
Sussex County 12
0% 0 of 12
Rare
Clarke County 11
0% 0 of 11
Rare
Fairfax County 10
0% 0 of 10
Rare

62 more Virginia counties have 1 to 9 tested wells for nitrate, too few to rate.

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Where to get your well tested for nitrate in Virginia

1

Low-cost state testing

Virginia Cooperative Extension runs well water clinics in about 70 counties a year, at $70 a kit. Check which tests it includes before you count on it for nitrate.

Virginia's private well page
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include nitrate.

Compare kits

Keep reading about wells in Virginia

Questions people ask about nitrate in Virginia

Is there nitrate in Virginia well water?

Nitrate is worth checking in 4 of the 14 Virginia counties with 10 or more tested wells, and rare in the rest. Across Virginia, about 1 in 28 tested wells had nitrate over the EPA limit of 10 mg/L (16 of 452). Across all tested wells in the US it's about 1 in 12. That's less often than in the country as a whole. Counties still differ, so check yours below.

Where can I get my well tested for nitrate in Virginia?

Virginia Cooperative Extension runs well water clinics in about 70 counties a year, at $70 a kit. If that doesn't cover you, use a lab certified by Virginia for drinking water, or a mail-in kit that includes nitrate from a certified lab.

See Virginia's list of certified labs, or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA limit of 10 mg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Department of Health (VDH), Office of Environmental Health Services.