We analyzed tap water quality data for hundreds of cities across the United States to identify those with the highest levels of radium. This ranking is based on 2026 data from the EPA and EWG databases.
Radium is a contaminant of growing concern in drinking water. The cities below have the highest detected levels based on the most recent testing data available.
Rankings at a Glance
Millersview, Texas
Millersview has radium detected at 15.84 pCi/L. 22 total contaminants were found in the water supply.
See full Millersview water report →Paint Rock, Texas
Paint Rock has radium detected at 15.84 pCi/L. 23 total contaminants were found in the water supply.
See full Paint Rock water report →Brady, Texas
Brady has radium detected at 14.88 pCi/L. 17 total contaminants were found in the water supply.
See full Brady water report →Manzanola, Colorado
Manzanola has radium detected at 13.18 pCi/L. 2 total contaminants were found in the water supply.
See full Manzanola water report →Wiley, Colorado
Wiley has radium detected at 12.74 pCi/L. 15 total contaminants were found in the water supply.
See full Wiley water report →Moriaty, New Mexico
Moriaty has radium detected at 8.90 pCi/L. 6 total contaminants were found in the water supply.
See full Moriaty water report →Lance Creek, Wyoming
Lance Creek has radium detected at 8.61 pCi/L. 7 total contaminants were found in the water supply.
See full Lance Creek water report →Cheraw, Colorado
Cheraw has radium detected at 7.37 pCi/L. 5 total contaminants were found in the water supply.
See full Cheraw water report →Annapolis, Missouri
Annapolis has radium detected at 7.05 pCi/L. 18 total contaminants were found in the water supply.
See full Annapolis water report →Theodosia, Missouri
Theodosia has radium detected at 6.55 pCi/L. 10 total contaminants were found in the water supply.
See full Theodosia water report →Byron, Michigan
Byron has radium detected at 6.50 pCi/L. 5 total contaminants were found in the water supply.
See full Byron water report →Raymond, Maine
Raymond has radium detected at 6.29 pCi/L. 6 total contaminants were found in the water supply.
See full Raymond water report →Welch, Oklahoma
Welch has radium detected at 6.08 pCi/L. 9 total contaminants were found in the water supply.
See full Welch water report →Wenona, Illinois
Wenona has radium detected at 5.69 pCi/L. 13 total contaminants were found in the water supply.
See full Wenona water report →Otsego, Minnesota
Otsego has radium detected at 5.60 pCi/L. 13 total contaminants were found in the water supply.
See full Otsego water report →Gibson, Georgia
Gibson has radium detected at 5.56 pCi/L. 8 total contaminants were found in the water supply.
See full Gibson water report →Andover, Minnesota
Andover has radium detected at 5.41 pCi/L. 20 total contaminants were found in the water supply.
See full Andover water report →Mount Pleasant, Iowa
Mount Pleasant has radium detected at 5.38 pCi/L. 16 total contaminants were found in the water supply.
See full Mount Pleasant water report →Hockessin, Delaware
Hockessin has radium detected at 5.35 pCi/L. 9 total contaminants were found in the water supply.
See full Hockessin water report →Trezvant, Tennessee
Trezvant has radium detected at 5.29 pCi/L. 2 total contaminants were found in the water supply.
See full Trezvant water report →Hasty, Colorado
Hasty has radium detected at 5.26 pCi/L. 11 total contaminants were found in the water supply.
See full Hasty water report →Trenary, Michigan
Trenary has radium detected at 5.22 pCi/L. 2 total contaminants were found in the water supply.
See full Trenary water report →Rush City, Minnesota
Rush City has radium detected at 5.21 pCi/L. 1 total contaminants were found in the water supply.
See full Rush City water report →Roopville, Georgia
Roopville has radium detected at 5.19 pCi/L. 15 total contaminants were found in the water supply.
See full Roopville water report →Elberta, Alabama
Elberta has radium detected at 5.19 pCi/L. 12 total contaminants were found in the water supply.
See full Elberta water report →What We Found: Key Patterns
The most frequently detected contaminants exceeding health guidelines across these cities are Radium, combined (-226 and -228), Total trihalomethanes (TTHMs), Haloacetic acids (HAA5). These appear repeatedly across different water systems and regions.
Geographically, the states most represented in this ranking are Colorado (4), Texas (3), Minnesota (3). Regional water sources, industrial activity, and agricultural runoff all contribute to local water quality variation.
Across all ranked cities, 168 contaminant readings exceed EWG health guidelines, but only 28 exceed EPA legal limits. This gap of 140 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 | Millersview | TX | 22 | 12 | 2 | 3,987 |
| 2 | Paint Rock | TX | 23 | 12 | 2 | 275 |
| 3 | Brady | TX | 17 | 10 | 1 | 5,371 |
| 4 | Manzanola | CO | 2 | 2 | 1 | 270 |
| 5 | Wiley | CO | 15 | 8 | 1 | 1,500 |
| 6 | Moriaty | NM | 6 | 3 | 1 | 34 |
| 7 | Lance Creek | WY | 7 | 3 | 1 | 0 |
| 8 | Cheraw | CO | 5 | 2 | 1 | 154 |
| 9 | Annapolis | MO | 18 | 12 | 1 | 0 |
| 10 | Theodosia | MO | 10 | 8 | 1 | 243 |
| 11 | Byron | MI | 5 | 4 | 1 | 581 |
| 12 | Raymond | ME | 6 | 3 | 1 | 50 |
| 13 | Welch | OK | 9 | 6 | 1 | 800 |
| 14 | Wenona | IL | 13 | 7 | 1 | 979 |
| 15 | Otsego | MN | 13 | 10 | 1 | 18,493 |
| 16 | Gibson | GA | 8 | 8 | 1 | 0 |
| 17 | Andover | MN | 20 | 12 | 1 | 21,455 |
| 18 | Mount Pleasant | IA | 16 | 8 | 1 | 0 |
| 19 | Hockessin | DE | 9 | 9 | 1 | 60 |
| 20 | Trezvant | TN | 2 | 2 | 1 | 0 |
| 21 | Hasty | CO | 11 | 6 | 1 | 244 |
| 22 | Trenary | MI | 2 | 2 | 1 | 175 |
| 23 | Rush City | MN | 1 | 1 | 1 | 80 |
| 24 | Roopville | GA | 15 | 10 | 2 | 1,000 |
| 25 | Elberta | AL | 12 | 8 | 1 | 10,824 |
Frequently Asked Questions
What cities have the highest levels of radium?
Our analysis of 2026 data identified the cities with the highest detected levels of radium. See the full ranking above.
Is radium dangerous in drinking water?
Radium has known health risks at elevated levels. The EWG sets health guidelines that are often stricter than EPA legal limits to account for the latest research on long-term exposure.
How do I remove radium from my water?
Reverse osmosis (RO) systems are the most effective at removing a wide range of contaminants. Check the specific contaminant details for recommended filtration technology.
What is the EPA legal limit for radium?
EPA legal limits vary by contaminant and may differ from EWG health guidelines. See individual city reports for specific legal limit comparisons.
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.
