Well water in Kansas
In Kansas, 20% of 124 tested well samples exceeded the EPA limit for arsenic (10 ug/L), based on public data from USGS Water Quality Portal and Kansas Geological Survey groundwater quality samples.
2,774 individual samples from 1,076 wells, 1939 to 2026. Data refreshed September 9, 2026.
These are KGS and groundwater management district sampling wells, not a survey of homeowners' wells.
What individual samples found
Each row summarizes every public sample for that contaminant inside Kansas. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Samples | Detected | Above limit | Median | Highest | Limit | |
|---|---|---|---|---|---|---|---|
| Arsenic 1977 to 2018 | 124 | 87% | 20% | 4.5 | 55 | 10 ug/L EPA limit | |
| Nitrate 1939 to 2021 | 222 | 82% | 13% | 0.865 | 129 | 10 mg/L EPA limit | |
| Uranium 1977 to 2024 | 315 | 93% | 3% | 3.94 | 75.6 | 30 ug/L EPA limit | |
| Radium (226 + 228) 1977 to 2021 | 318 | 92% | 3% | 0.245 | 23 | 5 pCi/L EPA limit | |
| E. coli 2000 to 2026 | 2,128 | 2% | 2% | 0 | 14,000 | 0 MPN/100mL EPA limit | |
| Lead 1976 to 2024 | 2,774 | 31% | <1% | 0 | 2,600 | 15 ug/L EPA limit | |
| Fluoride 1939 to 2018 | 131 | 100% | 0% | 0.4 | 3.7 | 4 mg/L EPA limit | |
| Copper 1976 to 2018 | 75 | 29% | 0% | 0 | 0.05 | 1.3 mg/L EPA limit | |
| Chloride 1939 to 2016 | 252 | 100% | no limit | 54.5 | 16,000 | 250 mg/L nuisance level | |
| Radon 1990 to 2018 | 140 | 99% | no limit | 370 | 3,100 | 2,000 pCi/L health guideline | |
| Sodium 1941 to 2013 | 130 | 100% | no limit | 49.5 | 1,600 | 20 mg/L health guideline | |
| Iron 1939 to 2013 | 130 | 92% | no limit | 115 | 40,700 | 300 ug/L nuisance level | |
| Manganese 1939 to 2016 | 130 | 92% | no limit | 275 | 2,230 | 300 ug/L health guideline |
Sampled fewer than 10 times, too few to summarize: PFOS (9), PFOA (9).
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What this means
The contaminants most often above their limit here are arsenic (20% of 124 samples), nitrate (13% of 222 samples), and uranium (3% of 315 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.
Chloride, Iron, and Manganese are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Kansas
- Volatile organic compounds (VOCs)11,919 leaking underground storage tank sites on record locally.
- Metals panel106 hazardous waste sites on record locally.
- Arsenic20% of 124 local samples were above the limit.
- Nitrate13% of 222 local samples were above the limit.
- Uranium3% of 315 local samples were above the limit.
- Radium (226 + 228)3% of 318 local samples were above the limit.
- E. coli2% of 2,128 local samples were above the limit.
- Lead<1% of 2,774 local samples were above the limit.
- RadonMedian local reading is 370 pCi/L.
Contamination sources on record in Kansas
KDHE records 11,919 leaking underground storage tank sites and 106 hazardous waste sites in Kansas, among 16,748 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 11,919
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 106
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 3,679
- other remediation projects
- 1,044
- other solid waste facilities
Treatment that fits the local profile
- Arsenic
- Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
- Nitrate
- Point-of-use reverse osmosis; Anion exchange; Distillation
- Uranium
- Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange
- Radium (226 + 228)
- Water softener (cation exchange); Point-of-use reverse osmosis
- E. coli
- Shock chlorination and fix the well cap or casing; UV disinfection whole-house; Chlorination system
Common questions
Is there arsenic in well water in Kansas?
Arsenic was detected in 87% of 124 public well samples in Kansas, and 20% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.
How high is radon in well water in Kansas?
The median radon level across 140 public samples in Kansas was 370 pCi/L, with a high of 3,100 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Kansas?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Counties in Kansas
- Cherokee11% lead
- Cowley4% lead
- Harvey29% arsenic
- Jackson26% e. coli
- Lyon4% lead
- Nemaha0% lead
- Reno0% lead
- Sedgwick7% uranium
97 counties have fewer than 30 public samples and are included in the Kansas totals above rather than shown separately: Allen, Anderson, Atchison, Barber, Barton, Bourbon, Brown, Butler, Chase, Chautauqua, Cheyenne, Clark, Clay, Cloud, Coffey, Comanche, Crawford, Decatur, Dickinson, Doniphan, Douglas, Edwards, Elk, Ellis, Ellsworth, Finney, Ford, Franklin, Geary, Gove, Graham, Grant, Gray, Greeley, Greenwood, Hamilton, Harper, Haskell, Hodgeman, Jefferson, Jewell, Johnson, Kearny, Kingman, Kiowa, Labette, Lane, Leavenworth, Lincoln, Linn, Logan, Marion, Marshall, McPherson, Meade, Miami, Mitchell, Montgomery, Morris, Morton, Neosho, Ness, Norton, Osage, Osborne, Ottawa, Pawnee, Phillips, Pottawatomie, Pratt, Rawlins, Republic, Rice, Riley, Rooks, Rush, Russell, Saline, Scott, Seward, Shawnee, Sheridan, Sherman, Smith, Stafford, Stanton, Stevens, Sumner, Thomas, Trego, Wabaunsee, Wallace, Washington, Wichita, Wilson, Woodson, Wyandotte.
Sources
- USGS Water Quality Portal: 6,515 samples in Kansas. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- Kansas Geological Survey groundwater quality samples: 372 samples in Kansas. Groundwater quality samples from the Kansas Geological Survey and Groundwater Management District 2, joined to WWC5 well records. Retrieved September 9, 2026.
- KDHE regulated sites: 16,748 regulated sites located in Kansas. Identified contaminated sites, leaking underground storage tank facilities and solid waste facilities from the Kansas Department of Health and Environment. Retrieved September 9, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.