Bicarbonate / Alkalinity
Cities measured
87
Detected in
87 / 87
Highest
412 mg/L — Rome
Overview
Bicarbonate is the principal alkalinity component in most drinking waters — it buffers against pH change. Stockholm's low-alkalinity granite-source water (reflecting granitic geology) has limited buffering capacity, making it naturally more corrosive to pipes.
Health Relevance
Bicarbonate at normal drinking water concentrations has no adverse health effects. The body produces it endogenously at large scale (the bicarbonate buffer system is the primary blood pH buffer).
Regulatory Limits
Drinking Water Directive 2020/2184
No EU regulatory limit.
Controversy & Contested Science
Low-alkalinity water (< 50 mg HCO₃⁻/L) is corrosive and leaches lead and copper from pipes. Stockholm Water compensates by adding lime (Ca(OH)₂) to raise pH and alkalinity. Critics argue this chemical treatment masks lead-pipe risks in older buildings rather than replacing the pipes — an infrastructure problem deferred by chemistry. Many Stockholm buildings constructed before 1960 retain lead connectors in internal plumbing that were never replaced.