Radium-226
radionuclide
Erosion of natural deposits.
EPA regulatory status
Legal limit (MCL)
No numeric MCL
Goal (MCLG)
0 pCi/L
No individual MCL — radium-226 is regulated only as part of the combined radium-226/228 limit of 5 pCi/L (see radium-226-228). MCLG = 0.
Health effects
Long-term exposure is associated with an increased risk of cancer.
This is general public-health information, not medical advice — consult your physician with any health concerns.
National violations
35,059
EPA's enforcement data (SDWIS/ECHO) records 35,059 violations of Radium-226's rule nationally.
How to remove Radium-226
cation exchange
NSF/ANSI 44
Frequently asked questions
What is Radium-226?
Radium-226 is a radionuclide regulated in US drinking water. Erosion of natural deposits.
What is the legal limit for Radium-226 in drinking water?
No individual MCL — radium-226 is regulated only as part of the combined radium-226/228 limit of 5 pCi/L (see radium-226-228). MCLG = 0.
What health effects does Radium-226 have?
Long-term exposure is associated with an increased risk of cancer.
How many violations of Radium-226 limits are on record nationally?
EPA's enforcement data (SDWIS/ECHO) records 35,059 violations of Radium-226's rule nationally.
How do I remove Radium-226 from my water?
Filter technologies certified to reduce Radium-226 include: cation exchange (NSF/ANSI 44), reverse osmosis (NSF/ANSI 58). Look for a filter independently certified against the specific NSF/ANSI standard for this contaminant — general "reduces contaminants" marketing claims are not the same as a contaminant-specific certification.
Source: EPA National Primary Drinking Water Regulations · Data as of 2026-07-16