Private wells
Kansas well water: who's on a well and what to test for
People on private wells
496,300
Homes on wells
16.2%
Est. above arsenic limit
6,200
Every Kansas county
Sorted by people on private wells. Arsenic and nitrate are modeled for typical wells in the county, not measured at yours; depth is the median of domestic well records.
| Sedgwick County | 175,200 | 31% | 5.1% | 3.5 | 64 ft |
| Reno County | 31,900 | 51% | 5.8% | 3.8 | 57 ft |
| Butler County | 22,700 | 32% | 5.1% | 0.6 | 95 ft |
| Riley County | 20,900 | 23% | 2.1% | 0.6 | 96 ft |
| Geary County | 13,800 | 31% | 3.0% | 0.6 | 100 ft |
| Harvey County | 12,800 | 36% | 6.5% | 1.4 | 75 ft |
| Saline County | 12,800 | 22% | 2.7% | 3.2 | 54 ft |
| Shawnee County | 9,300 | 4% | 2.6% | 0.8 | 60 ft |
| Barton County | 8,900 | 35% | 4.1% | 6.0 | 65 ft |
| McPherson County | 8,500 | 28% | 3.4% | 2.0 | 71 ft |
| Douglas County | 8,100 | 6% | 2.1% | 0.5 | 100 ft |
| Finney County | 8,000 | 20% | 6.1% | 6.5 | 255 ft |
| Ellis County | 7,500 | 27% | 3.5% | 5.8 | 50 ft |
| Sumner County | 7,200 | 31% | 2.7% | 6.3 | 55 ft |
| Dickinson County | 6,700 | 34% | 2.3% | 1.8 | 75 ft |
| Ford County | 6,600 | 21% | 3.0% | 4.0 | 168 ft |
| Wyandotte County | 6,400 | 4% | 2.7% | 0.2 | 90 ft |
| Leavenworth County | 6,100 | 8% | 2.4% | 0.3 | 101 ft |
| Pottawatomie County | 5,200 | 21% | 2.3% | 0.8 | 90 ft |
| Marion County | 4,200 | 37% | 4.4% | 1.9 | 70 ft |
| Johnson County | 3,900 | 1% | 2.0% | 0.6 | 110 ft |
| Kingman County | 3,800 | 51% | 3.5% | 7.6 | 64 ft |
| Rice County | 3,600 | 36% | 4.4% | 5.0 | 59 ft |
| Franklin County | 3,300 | 13% | 1.9% | 0.4 | 138 ft |
| Jefferson County | 2,900 | 16% | 2.2% | 0.5 | 60 ft |
| Cowley County | 2,800 | 8% | 5.8% | 2.0 | 82 ft |
| Pratt County | 2,700 | 25% | 3.2% | 9.7 | 95 ft |
| Jackson County | 2,700 | 19% | 2.1% | 0.6 | 80 ft |
| Ottawa County | 2,700 | 47% | 2.7% | 1.6 | 71 ft |
| Lyon County | 2,500 | 8% | 4.0% | 1.6 | 39 ft |
| Gray County | 2,400 | 41% | 3.9% | 5.6 | 225 ft |
| Cloud County | 2,400 | 25% | 3.6% | 2.7 | 98 ft |
| Clay County | 2,200 | 26% | 2.7% | 2.2 | 95 ft |
| Wabaunsee County | 2,200 | 36% | 3.6% | 0.7 | 80 ft |
| Montgomery County | 2,200 | 7% | 3.4% | 1.0 | 87 ft |
| Thomas County | 2,100 | 26% | 5.8% | 9.3 | 190 ft |
| Morris County | 2,100 | 45% | 6.0% | 0.7 | 85 ft |
| Stafford County | 2,000 | 49% | 3.9% | 6.7 | 68 ft |
| Cherokee County | 1,900 | 9% | 3.4% | 0.1 | 202 ft |
| Nemaha County | 1,900 | 16% | 2.4% | 0.6 | 80 ft |
| Washington County | 1,800 | 31% | 2.4% | 1.8 | 85 ft |
| Brown County | 1,700 | 16% | 2.2% | 1.5 | 79 ft |
| Seward County | 1,600 | 8% | 3.6% | 5.4 | 300 ft |
| Pawnee County | 1,600 | 26% | 3.5% | 5.1 | 72 ft |
| Ellsworth County | 1,600 | 29% | 3.4% | 3.0 | 100 ft |
| Marshall County | 1,600 | 15% | 2.4% | 0.5 | 76 ft |
| Grant County | 1,500 | 22% | 11.0% | 3.4 | 380 ft |
| Phillips County | 1,500 | 28% | 3.1% | 5.1 | 60 ft |
| Norton County | 1,500 | 29% | 4.3% | 5.0 | 96 ft |
| Kearny County | 1,400 | 38% | 8.7% | 8.4 | 226 ft |
| Doniphan County | 1,400 | 20% | 3.1% | 2.7 | 68 ft |
| Atchison County | 1,300 | 9% | 2.2% | 0.8 | 74 ft |
| Sherman County | 1,300 | 21% | 5.0% | 6.8 | 240 ft |
| Labette County | 1,300 | 5% | 1.5% | 0.8 | 61 ft |
| Allen County | 1,300 | 9% | 1.6% | 0.8 | 70 ft |
| Haskell County | 1,200 | 31% | 4.6% | 4.1 | 400 ft |
| Stevens County | 1,200 | 24% | 6.8% | 5.5 | 348 ft |
| Gove County | 1,200 | 42% | 5.4% | 10.4 | 75 ft |
| Sheridan County | 1,200 | 45% | 6.1% | 5.5 | 155 ft |
| Chase County | 1,200 | 46% | 6.6% | 0.6 | 55 ft |
| Osage County | 1,200 | 7% | 1.6% | 0.9 | 130 ft |
| Barber County | 1,100 | 28% | 2.9% | 5.1 | 59 ft |
| Osborne County | 1,100 | 26% | 1.5% | 4.2 | 50 ft |
| Scott County | 1,100 | 22% | 4.0% | 13.3 | 152 ft |
| Rawlins County | 1,100 | 42% | 4.5% | 6.1 | 150 ft |
| Miami County | 1,100 | 3% | 1.4% | 1.3 | 100 ft |
| Harper County | 1,100 | 19% | 2.8% | 10.0 | 52 ft |
| Decatur County | 1,100 | 39% | 5.7% | 6.5 | 105 ft |
| Kiowa County | 1,000 | 40% | 3.1% | 6.2 | 120 ft |
| Coffey County | 1,000 | 12% | 1.9% | 0.6 | 60 ft |
| Meade County | 1,000 | 25% | 2.8% | 3.6 | 200 ft |
| Graham County | 930 | 40% | 5.1% | 7.9 | 68 ft |
| Cheyenne County | 920 | 33% | 4.4% | 7.0 | 160 ft |
| Rooks County | 900 | 19% | 3.1% | 6.8 | 54 ft |
| Ness County | 880 | 32% | 3.5% | 6.1 | 55 ft |
| Lincoln County | 850 | 26% | 2.7% | 1.8 | 110 ft |
| Rush County | 840 | 28% | 3.0% | 2.8 | 170 ft |
| Wilson County | 830 | 9% | 2.2% | 1.1 | 55 ft |
| Edwards County | 810 | 27% | 3.3% | 8.1 | 76 ft |
| Neosho County | 750 | 4% | 1.5% | 0.9 | 75 ft |
| Mitchell County | 750 | 11% | 2.4% | 4.8 | 44 ft |
| Hodgeman County | 720 | 43% | 2.7% | 4.1 | 95 ft |
| Wichita County | 690 | 33% | 4.8% | 12.3 | 150 ft |
| Trego County | 690 | 23% | 4.0% | 6.6 | 62 ft |
| Wallace County | 660 | 39% | 6.2% | 7.2 | 137 ft |
| Hamilton County | 650 | 27% | 8.7% | 4.7 | 250 ft |
| Russell County | 620 | 9% | 3.0% | 2.7 | 80 ft |
| Logan County | 610 | 22% | 5.2% | 8.3 | 69 ft |
| Crawford County | 590 | 1% | 2.2% | 0.3 | 49 ft |
| Republic County | 590 | 12% | 3.1% | 3.9 | 63 ft |
| Lane County | 580 | 38% | 6.5% | 12.7 | 80 ft |
| Greenwood County | 550 | 11% | 3.6% | 0.7 | 57 ft |
| Jewell County | 540 | 19% | 3.1% | 7.0 | 70 ft |
| Smith County | 530 | 15% | 2.2% | 6.0 | 60 ft |
| Stanton County | 510 | 28% | 10.8% | 4.5 | 320 ft |
| Clark County | 490 | 23% | 2.7% | 3.9 | 103 ft |
| Linn County | 490 | 5% | 1.3% | 1.9 | 46 ft |
| Chautauqua County | 490 | 13% | 2.4% | 0.4 | 95 ft |
| Comanche County | 470 | 27% | 2.6% | 4.7 | 85 ft |
| Greeley County | 440 | 32% | 7.1% | 8.9 | 138 ft |
| Morton County | 430 | 17% | 7.3% | 6.0 | 250 ft |
| Woodson County | 310 | 11% | 2.1% | 1.2 | 80 ft |
| Elk County | 250 | 10% | 2.9% | 0.4 | 100 ft |
| Anderson County | 220 | 2% | 1.5% | 0.9 | 75 ft |
| Bourbon County | 40 | 0% | 1.6% | 0.6 | 100 ft |
Shading: red is among the highest counties nationally, amber the middle, green the lower range. Click a column to sort.
Most well users above the arsenic limit
- Reno County: about 640 people
- Sedgwick County: about 450 people
- Seward County: about 340 people
- Ford County: about 340 people
- Grant County: about 250 people
Highest modeled nitrate
- Scott County: 13.3 mg/L average (limit 10)
- Lane County: 12.7 mg/L average (limit 10)
- Wichita County: 12.3 mg/L average (limit 10)
- Gove County: 10.4 mg/L average (limit 10)
- Harper County: 10.0 mg/L average (limit 10)
Test first, then treat what the test finds
We may earn a commission from links below, at no cost to you. Picks follow the testing order, not who pays. How we make money.
1. Certified lab well test
Start here, every year
A mail-in kit analyzed by a certified lab measures bacteria, nitrate, arsenic, metals and more. Test strips cannot measure arsenic or uranium reliably.
2. Sediment pre-filter
Sand, silt or cloudy water
A 5-micron cartridge after the pressure tank catches sand, silt and rust before they reach fixtures or other filters. Cartridges are cheap and swap every few months.
3. Iron and sulfur filter
Orange stains or rotten-egg smell
Air-injection or oxidizing-media filters remove orange staining and rotten-egg smell. Size one from a lab result for iron, manganese and hydrogen sulfide.
4. UV disinfection system
Coliform bacteria in a test
Inactivates bacteria and viruses; usually for private wells or after boil notices.
5. Under-sink reverse osmosis
Arsenic, nitrate or uranium in a test
The most thorough option for drinking water: PFAS, lead, nitrate, arsenic and more. Look for NSF/ANSI 58.
6. Whole-house well filter
Several problems at once
Multi-stage sediment and carbon for every tap. Add UV if bacteria shows up, and choose stages from your lab results, not a guess.
Questions
Which Kansas counties rely most on wells?+
By share of homes: Kingman County (51%), Reno County (51%), Stafford County (49%), Ottawa County (47%), Chase County (46%). By number of people: Sedgwick County (175,200), Reno County (31,900), Butler County (22,700).
Is arsenic a problem in Kansas wells?+
USGS estimates about 6,200 Kansas well users have water above the 10 microgram per liter arsenic limit that applies to public systems, the largest numbers in Reno County, Sedgwick County, Seward County. Arsenic has no taste or smell, so only a lab test finds it.
Do I have to test my well when I sell a house in Kansas?+
We could not confirm a statewide rule for Kansas. Check with your county health department. Buyers can still make a lab test a condition of the offer.
How often should I test my well?+
No federal law covers private wells. EPA's drinking water limits apply to public water systems, so testing and treating a private well is up to the owner. EPA and CDC recommend testing at least once a year for coliform bacteria, nitrate, pH and total dissolved solids, and testing for arsenic, uranium, radon and other local concerns based on where you live.
Well-user counts, arsenic and nitrate figures are each a modeled estimate built from national datasets, not a count of tested wells, and well depths summarize drilling records rather than every well. Your own well can be very different from the county average, which is why the only answer for your home is a lab test. Sources: EPA Office of Research and Development, Water Source 2020 (private well estimates by census block); CDC Environmental Public Health Tracking, Well Water Index (from USGS nitrate and arsenic models); USGS, county-level domestic well population with arsenic above 10 micrograms per liter (Ayotte and others, 2017); USGS Synthesized Domestic Well Database for the Conterminous United States (SynDWell-US), McCarthy and others, 2025 (depth, where a county has 30+ usable records).