We analyzed tap water quality data for hundreds of cities in Kansas to identify the 25 with the most contaminants exceeding health guidelines. This ranking is based on 2026 data from the EPA and EWG databases.
While all public water systems must meet EPA legal limits, many health experts — including the Environmental Working Group — argue that these legal limits are outdated and don't reflect current scientific understanding of safe exposure levels. The cities below have the widest gap between what's in their water and what's considered safe by modern health standards.
Rankings at a Glance
Great Bend, Kansas
Great Bend has 20 contaminants exceeding EWG health guidelines out of 39 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Great Bend water report →Baldwin City, Kansas
Baldwin City has 16 contaminants exceeding EWG health guidelines out of 32 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Baldwin City water report →Russell, Kansas
Russell has 16 contaminants exceeding EWG health guidelines out of 30 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Russell water report →Arkansas City, Kansas
Arkansas City has 16 contaminants exceeding EWG health guidelines out of 29 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Arkansas City water report →Bonner Springs, Kansas
Bonner Springs has 16 contaminants exceeding EWG health guidelines out of 29 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Bonner Springs water report →Burr Oak, Kansas
Burr Oak has 16 contaminants exceeding EWG health guidelines out of 20 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Burr Oak water report →Fort Riley, Kansas
Fort Riley has 15 contaminants exceeding EWG health guidelines out of 30 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Fort Riley water report →Atchison, Kansas
Atchison has 15 contaminants exceeding EWG health guidelines out of 29 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Atchison water report →Galena, Kansas
Galena has 15 contaminants exceeding EWG health guidelines out of 24 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Galena water report →St Marys, Kansas
St Marys has 15 contaminants exceeding EWG health guidelines out of 23 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full St Marys water report →Norton, Kansas
Norton has 15 contaminants exceeding EWG health guidelines out of 22 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Norton water report →New Almelo, Kansas
New Almelo has 15 contaminants exceeding EWG health guidelines out of 22 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full New Almelo water report →Salina, Kansas
Salina has 14 contaminants exceeding EWG health guidelines out of 30 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Salina water report →Hays, Kansas
Hays has 14 contaminants exceeding EWG health guidelines out of 30 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Hays water report →Assaria, Kansas
Assaria has 14 contaminants exceeding EWG health guidelines out of 30 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Assaria water report →Alliance, Kansas
Alliance has 14 contaminants exceeding EWG health guidelines out of 30 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Alliance water report →Garden City, Kansas
Garden City has 14 contaminants exceeding EWG health guidelines out of 29 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Garden City water report →Pratt, Kansas
Pratt has 14 contaminants exceeding EWG health guidelines out of 29 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Pratt water report →Leavenworth, Kansas
Leavenworth has 14 contaminants exceeding EWG health guidelines out of 28 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Leavenworth water report →Winchester, Kansas
Winchester has 14 contaminants exceeding EWG health guidelines out of 28 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Winchester water report →Tonganoxie, Kansas
Tonganoxie has 14 contaminants exceeding EWG health guidelines out of 27 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Tonganoxie water report →Auburn, Kansas
Auburn has 14 contaminants exceeding EWG health guidelines out of 27 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Auburn water report →Liberal, Kansas
Liberal has 14 contaminants exceeding EWG health guidelines out of 25 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Liberal water report →Baxter Springs, Kansas
Baxter Springs has 14 contaminants exceeding EWG health guidelines out of 25 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Baxter Springs water report →Wichita, Kansas
Wichita has 14 contaminants exceeding EWG health guidelines out of 24 detected — significantly above the national average. Multiple known carcinogens were found at levels of concern.
See full Wichita water report →What We Found: Key Patterns
The most frequently detected contaminants exceeding health guidelines across these cities are Bromodichloromethane, Chloroform, Dibromoacetic acid. These appear repeatedly across different water systems and regions.
Water quality varies significantly even within the same state, driven by local geology, agricultural activity, and industrial proximity.
Across all ranked cities, 372 contaminant readings exceed EWG health guidelines, but only 4 exceed EPA legal limits. This gap of 368 highlights how legal standards may not fully protect public health — EPA limits haven't been updated for many contaminants in decades.
Full Rankings Table
| Rank | City | State | Detected | Above Guidelines | Above Legal | People Served |
|---|---|---|---|---|---|---|
| 1 | Great Bend | KS | 39 | 20 | 0 | 14,580 |
| 2 | Baldwin City | KS | 32 | 16 | 0 | 4,700 |
| 3 | Russell | KS | 30 | 16 | 0 | 4,388 |
| 4 | Arkansas City | KS | 29 | 16 | 0 | 11,929 |
| 5 | Bonner Springs | KS | 29 | 16 | 0 | 7,805 |
| 6 | Burr Oak | KS | 20 | 16 | 0 | 142 |
| 7 | Fort Riley | KS | 30 | 15 | 3 | 35,784 |
| 8 | Atchison | KS | 29 | 15 | 0 | 10,694 |
| 9 | Galena | KS | 24 | 15 | 0 | 2,743 |
| 10 | St Marys | KS | 23 | 15 | 0 | 2,781 |
| 11 | Norton | KS | 22 | 15 | 1 | 950 |
| 12 | New Almelo | KS | 22 | 15 | 0 | 0 |
| 13 | Salina | KS | 30 | 14 | 0 | 46,481 |
| 14 | Hays | KS | 30 | 14 | 0 | 20,795 |
| 15 | Assaria | KS | 30 | 14 | 0 | 936 |
| 16 | Alliance | KS | 30 | 14 | 0 | 300 |
| 17 | Garden City | KS | 29 | 14 | 0 | 35,126 |
| 18 | Pratt | KS | 29 | 14 | 0 | 6,573 |
| 19 | Leavenworth | KS | 28 | 14 | 0 | 38,757 |
| 20 | Winchester | KS | 28 | 14 | 0 | 3,635 |
| 21 | Tonganoxie | KS | 27 | 14 | 0 | 5,702 |
| 22 | Auburn | KS | 27 | 14 | 0 | 4,160 |
| 23 | Liberal | KS | 25 | 14 | 0 | 19,640 |
| 24 | Baxter Springs | KS | 25 | 14 | 0 | 3,852 |
| 25 | Wichita | KS | 24 | 14 | 0 | 395,699 |
Frequently Asked Questions
What city has the worst tap water in Kansas?
Based on 2026 data, Great Bend, KS has the most contaminants exceeding EWG health guidelines among the cities we analyzed.
How are cities ranked in this report?
Cities are ranked by the number of contaminants exceeding EWG health guidelines. These guidelines are typically stricter than EPA legal limits and reflect current scientific research on safe exposure levels.
Is my tap water safe if my city isn't on this list?
Not necessarily. Even cities not on this list may have contaminants of concern. We recommend checking your specific water quality using our free water scan tool.
What's the best water filter for contaminated water?
A reverse osmosis (RO) system is the most effective for removing the widest range of contaminants. For whole-home protection, a combination of RO for drinking water and a whole-home filter for showers and baths is recommended.
Related Reports
Data sources: Environmental Working Group (EWG) Tap Water Database, U.S. EPA Safe Drinking Water Information System (SDWIS)
Last updated: April 2026
Methodology: Contaminant levels are compared against both EPA legal limits (Maximum Contaminant Levels) and EWG health guidelines, which are often stricter and based on the latest scientific research.
