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WaterSafety

Selenium in Drinking Water

Inorganic Chemical · MCL: 50 ppb · 0 systems exceeding limit

Overview

Selenium is regulated under the Safe Drinking Water Act with an MCL of 50 ppb. The EPA Safe Drinking Water program sets and enforces the maximum contaminant levels shown here.

Health Effects

Exposure to Selenium above the MCL of 50 ppb may cause adverse health effects. Consult EPA fact sheets for detailed information.

Sources of Contamination

Selenium can enter drinking water from natural deposits, industrial discharges, or other sources.

Treatment & Removal

Treatment methods for Selenium include activated carbon filtration, reverse osmosis, and specialized media.

How to Remove Selenium From Water

These filtration methods are effective for reducing Selenium in drinking water:

Filter MethodEffectivenessCost RangeCertification
Reverse Osmosis (RO)High (varies)$200-500 (under-sink)NSF/ANSI 58
Activated Carbon BlockModerate (varies)$30-100 (pitcher/faucet)NSF/ANSI 53
Reverse Osmosis (RO) — details

Reverse osmosis is effective against most dissolved contaminants. Check specific certifications for this contaminant.

Activated Carbon Block — details

Effectiveness varies by contaminant. Look for filters specifically certified for this substance.

Water Systems with Selenium Detected