Radionuclides
Combined Radium in U.S. tap water
182 public water systems across 27 U.S. states report Combined Radium in their annual Consumer Confidence Report. 7 sit at or above the federal limit.
What it is
Combined radium-226 and radium-228 — naturally occurring radioactive elements.
Why it's regulated
Long-term exposure above the federal limit increases the risk of bone cancer.
At or above the federal limit (7)
| Water system | Measured | vs. limit |
|---|---|---|
| Pomona, CA 2024 annual report | 0–2024 pCi/L | 404.8× the limit |
| West Covina, CA 2024 annual report | 0.82 pCi/L | 16.4× the limit |
| Albuquerque, NM 2024 annual report | 0.13 | 13.0× the limit |
| City of Baltimore, MD 2024 annual report | 0.2–16 | 3.2× the limit |
| Lynn, MA 2024 annual report | 0.44–11 pCi/L | 2.2× the limit |
| Broad Creek, MD 2024 annual report | 1.6–8 pCi/L | 1.6× the limit |
| Crofton Odenton, MD 2024 annual report | 1.6–8 pCi/L | 1.6× the limit |
Approaching the limit (2)
| Water system | Measured | vs. limit |
|---|---|---|
| Baton Rouge, LA 2024 annual report | 4.81 pCi/L | 1.0× the limit |
| Carpenters Point, MD 2024 annual report | 4.1 pCi/L | 0.8× the limit |
Within the federal limit (95)
| Water system | Measured |
|---|---|
| Cape Coral, FL 2024 annual report | 3.7 pCi/L |
| Norman, OK 2024 annual report | 1.73–3 pCi/L |
| Oklahoma City, OK 2024 annual report | 3 pCi/L |
| Tucson, AZ 2024 annual report | 0–2.5 pCi/L |
| Carmel, IN 2024 annual report | 2.4 pCi/L |
| Madison, WI 2024 annual report | 2.4 pCi/L |
| Rialto, CA 2024 annual report | 2.4 pCi/L |
| Lafayette, LA 2024 annual report | 2.1 |
| Edmond, OK 2024 annual report | 1.59–2.05 pCi/L |
| Ann Arbor, MI 2024 annual report | 2 pCi/L |
| Lincoln, NE 2025 annual report | 1.05–2 |
| Centennial, CO 2023 annual report | 1.85 pCi/L |
| Houston, TX 2023 annual report | 1.77 pCi/L |
| Torrance, CA 2024 annual report | 0–1.69 pCi/L |
| Cedarville Mhp, MD 2024 annual report | 1.6 pCi/L |
| Brownsville, TX 2024 annual report | 1.5 pCi/L |
| Montgomery, AL 2024 annual report | 1.5 |
| Wichita Falls, TX 2024 annual report | 1.5–1.5 |
| Pueblo, CO 2023 annual report | 1.45 pCi/L |
| Beaches Water, MD 2024 annual report | 1.4 pCi/L |
| Chula Vista Sweetwater, CA 2024 annual report | 0.6–1.4 pCi/L |
| Broken Arrow, OK 2024 annual report | 1.146 pCi/L |
| Bonnie Brooke, MD 2024 annual report | 1.1 pCi/L |
| Denver, CO 2023 annual report | 1.1 pCi/L |
| Lakewood, CO 2024 annual report | 1.1 pCi/L |
| City of Hialeah, FL 2023 annual report | 0–1 pCi/L |
| City of Homestead, FL 2023 annual report | 0–1 pCi/L |
| City of North Miami Beach, FL 2023 annual report | 0–1 pCi/L |
| Miami Dade, FL 2023 annual report | 0–1 pCi/L |
| Spokane Valley, WA 2024 annual report | 0.97 pCi/L |
| Grand Rapids, MI 2025 annual report | 0.94 pCi/L |
| Boonsboro Keedysville, MD 2024 annual report | 0.9 pCi/L |
| Chandler, AZ 2024 annual report | 0.9 pCi/L |
| Colorado Springs, CO 2024 annual report | 0.9 pCi/L |
| Mesa, AZ 2024 annual report | 0–0.9 |
| Overland Park, KS 2023 annual report | 0.85 |
| Boston, MA 2024 annual report | 0.82 pCi/L |
| Malden, MA 2024 annual report | 0.82 pCi/L |
| Marlborough, MA 2024 annual report | 0.82 pCi/L |
| Cleveland, OH 2024 annual report | 0.801 pCi/L |
| Calverton School, MD 2024 annual report | 0.8 pCi/L |
| Gaither Manor Apartments, MD 2024 annual report | 0.8 pCi/L |
| Phoenix, AZ 2025 annual report | 0–0.8 pCi/L |
| Town of Accident, MD 2024 annual report | 0.8 ug/L |
| Cambridge, MA 2024 annual report | 0.75 pCi/L |
| Columbia, SC 2024 annual report | 0.735 |
| Chesapeake, VA 2023 annual report | 1.67–0.73 pCi/L |
| Suffolk, VA 2024 annual report | 1.67–0.73 pCi/L |
| Birmingham, AL 2024 annual report | 0.7 pCi/L |
| Campus Hills, MD 2024 annual report | 0.6 pCi/L |
Showing 50 of 95. The full list is in the JSON API.
Frequently asked
+What is Combined Radium?
Combined radium-226 and radium-228 — naturally occurring radioactive elements. Long-term exposure above the federal limit increases the risk of bone cancer.
+What is the federal limit for Combined Radium in drinking water?
The federal MCLG for Combined Radium is 0 . The EPA enforces this against the regulated reporting statistic (typically a running annual average or 90th percentile), not a single-sample spike.
+How many U.S. water systems have Combined Radium over the federal limit?
7 of the 182 public water systems on The Water Map report Combined Radium at or above its federal limit, spanning 27 U.S. states. The full list is on this page.
+How can I check if Combined Radium is in my city's tap water?
Search your city on The Water Map (https://www.thewatermap.com/) or browse the list on this page. Every U.S. public water utility is required to publish an annual Consumer Confidence Report that lists every contaminant it measured, including Combined Radium.