Zinc is an essential mineral found naturally in water. It can also enter tap water from industrial runoff and corrosion of galvanized plumbing. Excess zinc may cause health issues.

Zinc occurs naturally in water from rock and soil erosion. It's also widely used in industry for galvanizing steel and making alloys. Corrosion of galvanized pipes can increase zinc levels in tap water. While zinc is essential for human health in small amounts, excessive intake may cause gastrointestinal issues. The EPA has set a secondary standard of 5 mg/L for zinc in drinking water, primarily for taste and aesthetic reasons. Water utilities typically measure zinc levels using atomic absorption spectroscopy.