Selenium
metal
Discharge from petroleum refineries; erosion of natural deposits; discharge from mines.
EPA regulatory status
Legal limit (MCL)
0.05 mg/L
Goal (MCLG)
0.05 mg/L
MCL 0.05 mg/L (50 ppb). MCLG = 0.05 mg/L.
Health effects
An essential nutrient at low doses. Long-term overexposure can cause hair or fingernail loss, numbness in fingers or toes, and circulatory problems.
This is general public-health information, not medical advice — consult your physician with any health concerns.
National violations
38,061
EPA's enforcement data (SDWIS/ECHO) records 38,061 violations of Selenium's rule nationally.
How to remove Selenium
distillation
NSF/ANSI 62
Frequently asked questions
What is Selenium?
Selenium is a metal regulated in US drinking water. Discharge from petroleum refineries; erosion of natural deposits; discharge from mines.
What is the legal limit for Selenium in drinking water?
MCL 0.05 mg/L (50 ppb). MCLG = 0.05 mg/L.
What health effects does Selenium have?
An essential nutrient at low doses. Long-term overexposure can cause hair or fingernail loss, numbness in fingers or toes, and circulatory problems.
How many violations of Selenium limits are on record nationally?
EPA's enforcement data (SDWIS/ECHO) records 38,061 violations of Selenium's rule nationally.
How do I remove Selenium from my water?
Filter technologies certified to reduce Selenium include: reverse osmosis (NSF/ANSI 58), distillation (NSF/ANSI 62). 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