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Utah water profile

Nitrate in Utah community water systems

Utah's nitrate is mostly a mid-band story: few public systems exceed 5 mg/L, but a broad strip along the Wasatch Front reports enough to mark a clear human fingerprint on the basin-fill aquifers. See the pattern and what each reporting system measured in the three years from August 9, 2023 to August 9, 2026.

Browse all 117 Utah systems →

Search by the utility or system name shown on a water bill. Example: Salt Lake City Public Utilities. Private wells are not in this inventory.

23%
of the state’s 505 active community water systems have a current result here
117
systems with a current nitrate result
3,142,550
people served by those reporting systems
3.4%
of reporting systems at or above 5 mg/L
How to read these numbers Each system is placed into a band by its most recent reported result within a rolling three-year window. The bands describe how strongly human activity, read from nitrate, has marked a water source; they are not a safety verdict. Figures describe system reporting, not nitrate measured at an individual tap.

How Utah's systems fall across the five bands

Most systems report below 3 mg/L

Natural background
0.00–0.99 mg/L as N
35 systems · 650,668 served
Human impact likely
1.00–2.99 mg/L as N
42 systems · 1,193,787 served
Human impact clear
3.00–4.99 mg/L as N
36 systems · 1,214,906 served
Health-study range
5.00–9.99 mg/L as N
4 systems · 83,189 served
Above the federal limit
10.00 mg/L and above
0 systems · 0 served

Each system appears in one band only, placed by its most recent reported result in the current three-year window. Counts sit beside people served so a small number of larger systems cannot hide behind a row of tiny ones. Of the 4 systems reporting 5 mg/L or more, not one of them stayed there across its whole three-year range — each reached 5 only on a high sample and otherwise ran lower.

The named systems

Every reading here belongs to a utility with a name

Highest recent readings
SystemMost recent resultBandBased onPeople served
Smithfield City9.13 mg/La high point — runs lowerHealth-study rangeCCR summary, unverified10,223
Enoch City Water System9.01 mg/La high point — runs lowerHealth-study rangeCCR summary, unverified6,500
Eagle Mountain City6.50 mg/La high point — runs lowerHealth-study rangeCCR summary, unverified61,266
Hyde Park City Water System5.00 mg/La high point — runs lowerHealth-study rangeCCR summary, unverified5,200
Holliday Water Company4.97 mg/La high point — runs lowerHuman impact clearCCR summary, unverified15,000
Salt Lake City Water System4.97 mg/La high point — runs lowerHuman impact clearCCR summary, unverified381,174
University Of Utah4.97 mg/La high point — runs lowerHuman impact clearinherited from supplier57,080
Va Medical Center Slc4.97 mg/La high point — runs lowerHuman impact clearinherited from supplier2,798
Largest systems
SystemMost recent resultBandBased onPeople served
Salt Lake City Water System4.97 mg/La high point — runs lowerHuman impact clearCCR summary, unverified381,174
Granger-Hunter Improvement District2.90 mg/LHuman impact likelyinherited from supplier121,083
West Jordan City Water System4.17 mg/La high point — runs lowerHuman impact clearCCR summary, unverified117,025
Provo City0.49 mg/LNatural backgroundCCR summary, unverified116,288
St George City Water System0.56 mg/LNatural backgroundCCR summary, unverified105,240

Each result shows its date and what it rests on, so a lone sample is never taken for a settled measurement. A single high sample is not a complete account of what a household drinks.

Where higher nitrate concentrates

A mid-band pattern along the Wasatch Front

Human impact is clear on drinking water served in eleven of Utah’s 29 counties. Each is shaded by how many of its systems reported 3.00 mg/L as N or above. Shading counts systems, not severity — a county with many small utilities can outrank one holding a single larger system that reads higher. The table beside the map splits the two bands so that difference stays visible.

UT counties shaded by number of community water systems reporting nitrate at or above 3.00 mg/L as NCounties are shaded by how many community water systems reported nitrate at or above 3.00 mg/L as N in the three years from August 9, 2023 to August 9, 2026. The same counts appear in the table below this map.Cache County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveDavis County — 9 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveUtah County — 3 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveSanpete County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveIron County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveBox Elder County — 2 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveWashington County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveJuab County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveTooele County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveSalt Lake County — 13 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveWeber County — 2 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or above
none1–23–56–1112–2526+Number of drinking water systems reporting ≥3.00 mg/L NO₃–N per county as of August 9, 2026

Cache leads this layer with 2 reporting systems, followed by Iron, Utah. A mid-band pattern along the Wasatch Front.

Counties with the most systems at or above 3 mg/L as N
County3–4.99≥5Total ≥3
Salt Lake13013
Davis909
Utah314
Washington303
Box Elder202

Counts use each system's most recent reported result in the current three-year window. A system appears in only one of the two bands.

Find a specific Utah system

What the statewide pattern says

Basin fill under a growing urban corridor

Utah's higher nitrate concentrates along the Wasatch Front, where urban and agricultural nitrogen reach the shallow basin-fill aquifers — present as a broad mid-band signal rather than extreme highs.

The Wasatch Front's basin-fill aquifers supply about a third of Salt Lake Valley's public water, and USGS found the human fingerprint directly: nitrate above the roughly 2 mg/L background in 39 percent of the valley's public-supply wells, implicating fertilizer, leaking septic systems and sewer lines (Thiros and Manning, 2004). In newer residential areas, 87 percent of shallow monitoring wells exceeded background, with a median of 6.85 mg/L (Thiros, 2003).

Utah's trend picture is calmer than its neighbor states: a USGS–Utah DEQ analysis of four decades found basin nitrate trends small — between −0.08 and +0.02 mg/L per year — with water quality at any well tied to land use and flow paths across the larger up-gradient area (Miller, 2020). In the agricultural valleys the source sharpens: in Goshen Valley, the highest nitrate occurred in agricultural areas with manure the major source (Utah DEQ–USGS work cited in Miller, 2020).

The supported source reading is mixed urban and agricultural nitrogen — fertilizer, septic and sewer leakage along the urban corridor, manure in the farm valleys — not a certified source at any individual system. That mix is why Utah's map reads as a broad mid band rather than the sharp agricultural spikes of Kansas or Nebraska (Nolan and Hitt, 2006).

The general science — how nitrate moves, why some ground is vulnerable, and why the legacy lingers — is laid out with its sources on Where nitrate comes from.

Questions this page answers

What the Utah pattern does—and does not—say

Where does nitrate concentrate in Utah community water systems?

Cache leads this layer with 2 reporting systems, followed by Iron, Utah. A mid-band pattern along the Wasatch Front.

Why does Utah's map show a broad mid band instead of sharp hotspots?

Because the dominant Utah signal is mixed urban-and-agricultural nitrogen reaching shallow basin fill along a populated corridor — enough to mark a clear human fingerprint across many systems, but rarely the intense point loading that produces extreme highs in the High Plains states.

Can this page say the source is agriculture?

Only partly. In the farm valleys — Goshen is the studied case — manure is the documented major source. Along the urban Wasatch Front, USGS implicates fertilizer, septic and sewer leakage together. No reading certifies a source at an individual system.

Does a high public-system result mean a nearby private well is high?

No. It is a local sentinel, not a well-specific result. It shows that nitrogen and a transport pathway have reached groundwater in the area; a certified-lab test is still the only way to know a specific private well.

Sources and provenance

What this page rests on

  1. NitrateSmart inventory: 117 Utah community water systems with a current nitrate result in the three years from August 9, 2023 to August 9, 2026. Figures count people served by reporting systems, not measured tap exposure.
  2. Nolan BT, Hitt KJ (2006). Vulnerability of Shallow Groundwater and Drinking-Water Wells to Nitrate in the United States. Environmental Science & Technology 40(24):7834–7840.
  3. Dubrovsky NM, and others (2010). Nutrients in the Nation's Streams and Groundwater, 1992–2004. USGS Circular 1350.
  4. Thiros SA, Manning AH (2004). Quality and sources of ground water used for public supply in Salt Lake Valley, Salt Lake County, Utah, 2001. USGS Water-Resources Investigations Report 03-4325 — nitrate above background in 39% of public-supply wells.
  5. Thiros SA (2003). Quality and sources of shallow ground water in areas of recent residential development in Salt Lake Valley. USGS Water-Resources Investigations Report 03-4028 — 87% of shallow residential wells above background; median 6.85 mg/L.
  6. Miller OL (2020). Quantifying trends in arsenic, nitrate, and dissolved solids from selected wells in Utah. USGS Scientific Investigations Report 2020-5047 — small basin trends; manure the major source in Goshen Valley agriculture.