Tested Water

Nitrate in North Dakota well water, by county

Nitrate is worth checking in 2 of the 7 North Dakota 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 North Dakota compares with the rest of the country

Across North Dakota, about 1 in 34 tested wells had nitrate over the EPA limit of 10 mg/L (7 of 237). 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
Ransom County 12
8% 1 of 12
Worth checking
Benson County 77
6% 5 of 77
Worth checking
Mountrail County 39
0% 0 of 39
Rare
Eddy County 21
0% 0 of 21
Rare
Dunn County 15
0% 0 of 15
Rare
McLean County 14
0% 0 of 14
Rare
Rolette County 12
0% 0 of 12
Rare

16 more North Dakota 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 North Dakota

1

Your county health department

North Dakota doesn't run a statewide free testing program that we know of. Some county health departments test wells or sell kits, so call yours first.

North Dakota'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 North Dakota

Questions people ask about nitrate in North Dakota

Is there nitrate in North Dakota well water?

Nitrate is worth checking in 2 of the 7 North Dakota counties with 10 or more tested wells, and rare in the rest. Across North Dakota, about 1 in 34 tested wells had nitrate over the EPA limit of 10 mg/L (7 of 237). 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 North Dakota?

Use a lab certified by North Dakota for drinking water, or a mail-in kit that includes nitrate from a certified lab. Some county health departments test wells too, so call yours first.

See North Dakota'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 Environmental Quality.