Cyanide in Drinking Water

EPA Limit: 0.2 mg/L

The EPA maximum contaminant level for cyanide is 0.2 mg/L (as free cyanide).

Where Does Cyanide Come From?

Cyanide can enter water from industrial discharges, particularly from mining, metal plating, and chemical manufacturing. It does not commonly occur naturally at significant levels.

Health Risks

Short-term exposure at high levels can be rapidly fatal. Lower-level long-term exposure can cause nerve damage and thyroid problems.

What Should I Do?

Reverse osmosis and ion exchange can remove cyanide. Chlorination (used by water systems) also breaks down cyanide effectively.