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.
Paint Rock, Texas
Paint Rock has radium detected at 15.84 pCi/L. 23 total contaminants were found in the water supply.
Brady, Texas
Brady has radium detected at 14.88 pCi/L. 17 total contaminants were found in the water supply.
Manzanola, Colorado
Manzanola has radium detected at 13.18 pCi/L. 2 total contaminants were found in the water supply.
Wiley, Colorado
Wiley has radium detected at 12.74 pCi/L. 15 total contaminants were found in the water supply.
Moriaty, New Mexico
Moriaty has radium detected at 8.90 pCi/L. 6 total contaminants were found in the water supply.
Lance Creek, Wyoming
Lance Creek has radium detected at 8.61 pCi/L. 7 total contaminants were found in the water supply.
Cheraw, Colorado
Cheraw has radium detected at 7.37 pCi/L. 5 total contaminants were found in the water supply.
Annapolis, Missouri
Annapolis has radium detected at 7.05 pCi/L. 18 total contaminants were found in the water supply.
Theodosia, Missouri
Theodosia has radium detected at 6.55 pCi/L. 10 total contaminants were found in the water supply.
Byron, Michigan
Byron has radium detected at 6.50 pCi/L. 5 total contaminants were found in the water supply.
Raymond, Maine
Raymond has radium detected at 6.29 pCi/L. 6 total contaminants were found in the water supply.
Welch, Oklahoma
Welch has radium detected at 6.08 pCi/L. 9 total contaminants were found in the water supply.
Wenona, Illinois
Wenona has radium detected at 5.69 pCi/L. 13 total contaminants were found in the water supply.
Otsego, Minnesota
Otsego has radium detected at 5.60 pCi/L. 13 total contaminants were found in the water supply.
Gibson, Georgia
Gibson has radium detected at 5.56 pCi/L. 8 total contaminants were found in the water supply.
Andover, Minnesota
Andover has radium detected at 5.41 pCi/L. 20 total contaminants were found in the water supply.
Mount Pleasant, Iowa
Mount Pleasant has radium detected at 5.38 pCi/L. 16 total contaminants were found in the water supply.
Hockessin, Delaware
Hockessin has radium detected at 5.35 pCi/L. 9 total contaminants were found in the water supply.
Trezvant, Tennessee
Trezvant has radium detected at 5.29 pCi/L. 2 total contaminants were found in the water supply.
Hasty, Colorado
Hasty has radium detected at 5.26 pCi/L. 11 total contaminants were found in the water supply.
Trenary, Michigan
Trenary has radium detected at 5.22 pCi/L. 2 total contaminants were found in the water supply.
Rush City, Minnesota
Rush City has radium detected at 5.21 pCi/L. 1 total contaminants were found in the water supply.
Roopville, Georgia
Roopville has radium detected at 5.19 pCi/L. 15 total contaminants were found in the water supply.
Elberta, Alabama
Elberta has radium detected at 5.19 pCi/L. 12 total contaminants were found in the water supply.
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: September 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.
