Kansas
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Kansas water profile

Nitrate in Kansas community water systems

Kansas runs higher than most states: a large share of its community water systems report nitrate at or above 3 mg/L. The pattern sits over the High Plains aquifer and its river valleys, under decades of irrigated cropland. See where it concentrates and what each reporting system measured in the three years from August 9, 2023 to August 9, 2026.

Browse all 547 Kansas systems →

Search by the utility or system name shown on a water bill. Example: City of Wichita. Private wells are not in this inventory.

64%
of the state’s 855 active community water systems have a current result here
547
systems with a current nitrate result
2,284,407
people served by those reporting systems
37.7%
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 Kansas's systems fall across the five bands

A large share of systems report at or above 3 mg/L

Natural background
0.00–0.99 mg/L as N
93 systems · 1,480,019 served
Human impact likely
1.00–2.99 mg/L as N
143 systems · 401,643 served
Human impact clear
3.00–4.99 mg/L as N
105 systems · 167,567 served
Health-study range
5.00–9.99 mg/L as N
183 systems · 217,168 served
Above the federal limit
10.00 mg/L and above
23 systems · 18,010 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 206 systems reporting 5 mg/L or more, 136 stayed at or above 5 across the whole three-year range; the other 70 reached it only on a high sample and otherwise ran lower.

Most recent reading Jun 2026; the typical system was last tested around Apr 2025. 505 systems sampled their own water; 42 systems carry a supplier’s result.

The named systems

Every reading here belongs to a utility with a name

Highest recent readings
SystemMost recent resultBandBased onPeople served
Ford, City Of22.00 mg/LFeb 2025Above the federal limitCCR summary, unverified204
Reno Co Rwd 120.00 mg/LOct 2025Above the federal limitCCR summary, unverified150
Copeland, City Of18.30 mg/LMay 2025a high point — runs lowerAbove the federal limitCCR summary, unverified251
Damar, City Of16.00 mg/LFeb 2025a high point — runs lowerAbove the federal limitCCR summary, unverified115
Rooks Co Rwd 316.00 mg/LFeb 2025a high point — runs lowerAbove the federal limitCCR summary, unverified380
St George, City Of16.00 mg/LOct 2025a high point — runs lowerAbove the federal limitCCR summary, unverified998
Sylvia, City Of14.00 mg/LFeb 2025Above the federal limitCCR summary, unverified210
Pratt, City Of13.00 mg/LNov 2025a high point — runs lowerAbove the federal limitCCR summary, unverified6,573
Largest systems
SystemMost recent resultBandBased onPeople served
Water District 1 Of Johnson Co0.90 mg/LAug 2025Natural backgroundCCR summary, unverified490,000
Wichita, City Of0.82 mg/LJul 2025Natural backgroundCCR summary, unverified395,699
Kansas City Board Of Public Utilities0.66 mg/LMay 2025Natural backgroundCCR summary, unverified152,960
Topeka, City Of1.30 mg/LHuman impact likelyCCR summary, unverified125,963
Lawrence, City Of0.78 mg/LNatural backgroundCCR summary, unverified95,256

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

Higher results spread across the irrigated west and center

Human impact is clear on drinking water served in 83 of Kansas’s 105 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.

KS 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.Norton County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveLane County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveMarion County — 1 system at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveBarber County — 3 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveEdwards County — 1 system at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveThomas County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveFord County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveChase County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveWallace County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveCloud County — 3 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveNess County — 1 system at 3.00–4.99 mg/L as N; 5 systems at 5.00 mg/L as N or aboveEllis County — 1 system at 3.00–4.99 mg/L as N; 10 systems at 5.00 mg/L as N or aboveJackson County — 7 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveScott County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or abovePratt County — 0 systems at 3.00–4.99 mg/L as N; 6 systems at 5.00 mg/L as N or abovePhillips County — 2 systems at 3.00–4.99 mg/L as N; 4 systems at 5.00 mg/L as N or aboveGrant County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveGraham County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveTrego County — 1 system at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveHamilton County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveDecatur County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveWashington County — 1 system at 3.00–4.99 mg/L as N; 9 systems at 5.00 mg/L as N or aboveGray County — 1 system at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveGeary County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveWichita County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveClay County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveSheridan County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveKiowa County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveOsage County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveSherman County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveRooks County — 0 systems at 3.00–4.99 mg/L as N; 5 systems at 5.00 mg/L as N or aboveSaline County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveEllsworth County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveStevens County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveDoniphan County — 0 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveSedgwick County — 1 system at 3.00–4.99 mg/L as N; 7 systems at 5.00 mg/L as N or aboveSmith County — 1 system at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveHarvey County — 8 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveBrown County — 0 systems at 3.00–4.99 mg/L as N; 10 systems at 5.00 mg/L as N or aboveCheyenne County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveGreeley County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveSumner County — 5 systems at 3.00–4.99 mg/L as N; 6 systems at 5.00 mg/L as N or abovePottawatomie County — 3 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveKingman County — 0 systems at 3.00–4.99 mg/L as N; 6 systems at 5.00 mg/L as N or aboveMitchell County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveHodgeman County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveMorris County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveRush County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveStafford County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveFinney County — 6 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveJefferson County — 2 systems at 3.00–4.99 mg/L as N; 5 systems at 5.00 mg/L as N or abovePawnee County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveClark County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveStanton County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveComanche County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveRawlins County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveCherokee County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveShawnee County — 1 system at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveJewell County — 2 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveMarshall County — 3 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveNemaha County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveMorton County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveOttawa County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveRussell County — 2 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveDouglas County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveRepublic County — 2 systems at 3.00–4.99 mg/L as N; 6 systems at 5.00 mg/L as N or aboveLeavenworth County — 0 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveOsborne County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveRice County — 3 systems at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveDickinson County — 4 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveReno County — 0 systems at 3.00–4.99 mg/L as N; 11 systems at 5.00 mg/L as N or aboveLogan County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveHaskell County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveGove County — 1 system at 3.00–4.99 mg/L as N; 3 systems at 5.00 mg/L as N or aboveMeade County — 1 system at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveHarper County — 0 systems at 3.00–4.99 mg/L as N; 7 systems at 5.00 mg/L as N or aboveRiley County — 0 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveLincoln County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveSeward County — 3 systems at 3.00–4.99 mg/L as N; 0 systems at 5.00 mg/L as N or aboveBarton County — 1 system at 3.00–4.99 mg/L as N; 5 systems at 5.00 mg/L as N or aboveMcPherson County — 2 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveCowley County — 2 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveButler County — 1 system at 3.00–4.99 mg/L as N; 1 system 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

Reno leads this layer with 11 reporting systems, followed by Brown, Ellis, Washington. Higher results spread across the irrigated west and center.

Counties with the most systems at or above 3 mg/L as N
County3–4.99≥5Total ≥3
Ellis11011
Reno01111
Sumner5611
Brown01010
Washington1910

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 Kansas system

What the statewide pattern says

A High Plains irrigation pattern

Kansas's higher nitrate is a groundwater story: the Ogallala and its river-valley aquifers sit under some of the country's most intensively irrigated cropland, and nitrate reaches them even where the water table is deep.

Western and central Kansas sit over the High Plains (Ogallala) aquifer — well-drained sand and gravel — while the east draws on river-valley alluvium. What ties the state together is irrigated agriculture and how nitrate travels underground (Nolan and Hitt, 2006). USGS vulnerability mapping found the highest High Plains nitrate risk exactly where a shallow water table, little unsaturated-zone clay, and irrigated cropland coincide (Gurdak and Qi, 2006).

The counterintuitive part is depth. Regional recharge across the High Plains is tiny — under a third of an inch a year — but it is not spread evenly. Playas, the shallow seasonal basins that dot the plains, focus recharge at a few points, and irrigation return carries nitrate down through them. Kansas Geological Survey work in Ford County shows nitrate migrating through a silty vadose zone 75 to 150 feet thick, so a deep water table is no guarantee of low nitrate (Kansas Geological Survey Open-File Report 2007-14).

The supported source reading is agricultural, dominated by irrigated-cropland fertilizer and irrigation return — not a certified source at any individual system. Kansas also pioneered Local Enhanced Management Areas, where a groundwater district can adopt enforceable local rules — aimed mainly at slowing Ogallala depletion, but a rare case of local groundwater governance with teeth. As everywhere, the ground holds decades of past nitrogen, so change is slow (Dubrovsky and others, 2010).

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 Kansas pattern does—and does not—say

Where does nitrate concentrate in Kansas community water systems?

Reno leads this layer with 11 reporting systems, followed by Brown, Ellis, Washington. Higher results spread across the irrigated west and center.

Does a deep well on the Kansas High Plains mean low nitrate?

Not reliably. Regional recharge is under a third of an inch a year, but playas and irrigation return focus it, and Kansas Geological Survey monitoring shows nitrate migrating through vadose zones 75 to 150 feet thick. Deep wells run lower on average, but depth is not a guarantee here.

Can this page say the source is agriculture?

At the zone level, yes — carefully. Over the Ogallala and its river valleys, the supported reading is irrigated-cropland fertilizer and irrigation return, matching USGS High Plains vulnerability mapping. The evidence does not certify a source at each 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: 547 Kansas 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. Gurdak JJ, Qi SL (2006). Vulnerability of Recently Recharged Ground Water in the High Plains Aquifer to Nitrate Contamination. USGS Scientific Investigations Report 2006-5050.
  5. Townsend MA, Young DP (2007). Fate of nitrate beneath fields irrigated with treated wastewater in Ford County, Kansas. Kansas Geological Survey Open-File Report 2007-14 — nitrate migrating through a 75–150 ft silty vadose zone via irrigation-return preferential flow.