Selenium in Drinking Water

EPA Limit: 0.05 mg/L

The EPA maximum contaminant level for selenium is 0.05 mg/L (50 parts per billion).

Where Does Selenium Come From?

Selenium occurs naturally in some soils and rocks, particularly in the western United States. It can also come from petroleum refining, mining, and irrigation drainage.

Health Risks

Long-term exposure above the MCL can cause hair and fingernail loss, numbness in fingers and toes, and circulatory problems. Very high levels can cause kidney, liver, and nervous system damage.

What Should I Do?

Reverse osmosis and activated alumina are effective at removing selenium. Ion exchange may also work depending on the form of selenium present.