Cyanide in Drinking Water
EPA limits, health effects, and what to do if your water is affected.
🩨 Health Effects
Short-term exposure above the MCL can cause rapid breathing, tremors, and other nervous system effects. Long-term exposure can cause nerve damage and thyroid problems.
📍 Sources in Water
Enters water from discharge of steel and plastics factories and from fertilizer production. Cyanide is used in gold mining (heap leaching) and can contaminate water near mining sites.
✅ What To Do
Reverse osmosis and chlorination can effectively remove cyanide from water. Activated carbon filters may help. Cyanide violations are uncommon but do occur in industrial areas.
Check your tap water for Cyanide
Search your ZIP code to see if your water system has had Cyanide violations, plus lead testing results and an overall safety grade.
Search your ZIP code →Data from the EPA's Safe Drinking Water Information System (SDWIS). MCLs reflect minimum federal standards; some contaminants may pose health risks below these thresholds.