Tap water hardness in Rio de Janeiro

We have published hardness data for 44 cities in Rio de Janeiro. The median is 14 mg/L; the hardest water is in São Francisco de Itabapoana (96 mg/L), the softest in Nova Friburgo (5 mg/L).

0 % of these cities have hard or very hard water (over 120 mg/L).

Portaria GM/MS nº 888/2021 sets a maximum of 300 mg/L CaCO₃ for total hardness (dureza total); operators report it in mg/L to SISAGUA.

Cities in Rio de Janeiro, hardest first

All cities in Brazil →