Sodium occurs naturally in water and comes from road salt and water softeners. While essential for health, high intake can contribute to high blood pressure.

Sodium is ubiquitous in nature and essential for human health in small amounts. It enters drinking water through natural mineral deposits, seawater intrusion, and human activities. Road salt application and water softening processes are significant contributors to elevated sodium levels in water supplies. While sodium is not regulated as a primary drinking water contaminant, the EPA recommends a limit of 20 mg/L for individuals on low-sodium diets. Water utilities typically measure sodium levels using atomic absorption spectroscopy or ion chromatography methods.