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Nitrate in Utah well water, by county

By the Tested Water teamLab data from the USGS and EPA Water Quality Portal, 2000 to 2025Updated November 8, 2026

Nitrate is widespread, over the limit in 15% or more of tested wells, in 3 of the 24 Utah counties with 10 or more tested wells. 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.

Find a nitrate test See every county

How Utah compares with the rest of the country

Across Utah, about 1 in 16 tested wells had nitrate over the EPA limit of 10 mg/L (98 of 1,598). 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
Weber County 39
31% 12 of 39
 Widespread
Emery County 26
31% 8 of 26
 Widespread
Sevier County 13
15% 2 of 13
 Widespread
Millard County 120
12% 14 of 120
 Worth checking
Utah County 86
9% 8 of 86
 Worth checking
San Juan County 71
8% 6 of 71
 Worth checking
Washington County 72
8% 6 of 72
 Worth checking
Kane County 12
8% 1 of 12
 Worth checking
Tooele County 167
6% 10 of 167
 Worth checking
Morgan County 52
6%* 3 of 52
 Worth checking
Iron County 157
5% 8 of 157
 Worth checking
Beaver County 217
5% 10 of 217
 Rare
Box Elder County 47
4% 2 of 47
 Rare
Sanpete County 24
4% 1 of 24
 Rare
Uintah County 55
4% 2 of 55
 Rare
Davis County 60
3% 2 of 60
 Rare
Salt Lake County 143
2% 3 of 143
 Rare
Grand County 70
0% 0 of 70
 Rare
Summit County 37
0% 0 of 37
 Rare
Juab County 31
0% 0 of 31
 Rare
Wasatch County 24
0% 0 of 24
 Rare
Duchesne County 23
0% 0 of 23
 Rare
Cache County 21
0% 0 of 21
 Rare
Wayne County 13
0% 0 of 13
 Rare

* Likely overstated. These shares come from a narrow set of wells, so they probably run high for the county as a whole:

  • Morgan County: Almost all of these tests come from a single agency, mostly before 2013 in one small part of the county, so this likely overstates it.

4 more Utah 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 Utah

1

Your county health department

Utah 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.

Utah's private well page
2

A lab Utah certifies

Ask for nitrate by name. Results from a certified lab count for a home sale or a loan.

Labs certified by Utah
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 Utah

Questions people ask about nitrate in Utah

Is there nitrate in Utah well water?

Nitrate is widespread, over the limit in 15% or more of tested wells, in 3 of the 24 Utah counties with 10 or more tested wells. Across Utah, about 1 in 16 tested wells had nitrate over the EPA limit of 10 mg/L (98 of 1,598). 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 Utah?

Use a lab certified by Utah 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 Utah'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 and Human Services (Utah Public Health Laboratory) and local health departments.