Arsenic in Drinking Water

EPA Limit: 0.010 mg/L

The EPA set the maximum contaminant level for arsenic at 0.010 mg/L (10 parts per billion) in 2006, lowering it from the previous standard of 0.050 mg/L to reduce cancer risk.

Where Does Arsenic Come From?

Arsenic occurs naturally in rock and soil and can dissolve into groundwater. It can also come from industrial and agricultural runoff. Groundwater sources in the western United States are particularly prone to elevated arsenic levels.

Health Risks

Long-term exposure to arsenic in drinking water is associated with increased risk of cancer (skin, bladder, lung), cardiovascular disease, diabetes, and skin changes. It can also affect cognitive development in children.

What Should I Do?

If your water system has arsenic violations, use a reverse osmosis filter or an arsenic-specific adsorption filter for drinking and cooking water. Boiling water does not remove arsenic and actually concentrates it.