Question 1

What is the EPA limit for selenium in drinking water?

Accepted Answer

The EPA Maximum Contaminant Level (MCL) for selenium is 0.05 ppm. Public water systems must keep selenium below this level.

Question 2

What are the health effects of selenium in drinking water?

Accepted Answer

Selenium is unique among drinking water contaminants because it is an essential nutrient at low doses but toxic at high doses. The EPA MCL of 50 ppb reflects this narrow therapeutic window. Chronic exposure above the MCL causes selenosis, a

Question 3

Where does selenium in drinking water come from?

Accepted Answer

Selenium enters drinking water primarily through natural geological sources. Cretaceous-era marine shales in the western US (particularly Wyoming, Colorado, Montana, Utah, and the Dakotas) contain elevated selenium that leaches into groundw

Question 4

How do I remove selenium from my drinking water?

Accepted Answer

Selenium is effectively removed by: Reverse Osmosis, Anion Exchange, Activated Alumina. Look for NSF-certified filters that explicitly list selenium reduction.

Selenium in Drinking Water - EPA MCL, Health Effects & Removal