Alkalinity measures water's ability to neutralize acids. It comes from dissolved minerals and affects taste and pipe corrosion, but has no direct health impacts.

Alkalinity primarily comes from rocks and soils containing carbonate, bicarbonate, and hydroxide compounds. As water moves through these materials, it dissolves these substances, increasing its alkalinity. While not a health concern, alkalinity is crucial for water quality management. It helps buffer pH changes, protecting aquatic life and reducing pipe corrosion in water distribution systems. Measured in mg/L as calcium carbonate, alkalinity testing is a standard part of water quality monitoring programs for both natural and treated water sources.