Bicarbonate in Drinking Water: What It Is & Health Effects

Overview of Bicarbonate in Drinking Water

• What it is: Bicarbonate (HCO₃) is a natural buffer that regulates water's pH and contributes to alkalinity. It's formed when carbon dioxide dissolves in water and reacts with carbonate minerals.
• Why it matters: Bicarbonate gives water its "softness" and smooth mouthfeel. It's the signature component of famous mineral waters and may aid digestion by neutralizing stomach acid after meals.
• Natural sources: Dissolves from limestone, dolomite, and chalk as groundwater moves through rock. Volcanic and geothermal waters often have elevated bicarbonate. Deep aquifers typically have more than surface water.
• Optimal range (100–300 mg/L): Water in this range has a pleasant, slightly sweet taste and silky texture. Classic European mineral waters like Evian and Volvic fall here. Good for everyday hydration.
• Too high (>600 mg/L): Creates highly alkaline water with a distinct mineral taste. Waters like Vichy or Gerolsteiner have very high bicarbonate. Best consumed occasionally rather than as primary hydration.
• Too low (<50 mg/L): Water may taste flat or slightly acidic. Less buffering capacity means pH can fluctuate more. Common in rain-fed surface water and heavily treated municipal supplies.