Radium-226 in Drinking Water

Reference information plus historical EPA compliance records associated with radium-226.

EPA Limit (MCL)

5 pCi/L

EPA Goal (MCLG)

0 pCi/L

Category

Radionuclides

Regulatory values are a concise reference, not legal or medical advice. Confirm the current standard and rule-specific details on EPA.gov.

Health Effects

Increased cancer risk

Common Sources

Erosion of natural deposits

Treatment Considerations for Radium-226

Commonly cited treatment approaches include: Ion exchange, reverse osmosis. Choose treatment only after a certified water test identifies the substance and concentration; verify NSF/ANSI certification and consult a qualified local professional when needed.

13,112

Historical Violation Records

3,373

Systems With Records

Historical Radium-226 Records by State

StateRecordsSystems
Illinois2,485299
North Carolina1,094148
Mississippi1,040160
Oregon995664
Texas994104
Colorado970138
Missouri62652
Iowa525180
Oklahoma486160
Connecticut479178
South Dakota383279
Virginia28297
Arkansas25125
Wisconsin24258
Alaska23689
Montana20683
South Carolina20318
Arizona18767
Vermont16124
Georgia14966

Systems With the Most Radium-226 Violation Records

Frequently Asked Questions

What is Radium-226 and why can it appear in drinking-water records?

Radium-226 can be associated with drinking water through: Erosion of natural deposits.

What reference value does this page show?

The summarized EPA Maximum Contaminant Level is 5 pCi/L. Some substances use action levels or rule-specific thresholds instead, so verify the current EPA standard.

Does a historical violation record mean it is in my tap today?

No. A compliance record may be historical or resolved. Use the latest Consumer Confidence Report or a certified test for current local conditions.