Desmarchais-Crawford Water Hardness & Quality Report (2026)

Desmarchais-Crawford (a residential sector of Montréal's Sud-Ouest borough, in the LaSalle–Verdun area along the St. Lawrence riverfront, adjacent to the Desmarchais and Crawford Park areas) receives its drinking water through Ville de Montréal — Direction de l'eau potable, drawing from the St. Lawrence River via the Atwater Water Treatment Plant. Treatment includes ozonation, biofiltration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) standards. Hardness in this distribution zone is 100.5 mg/L (5.9 gpg) — classified as moderately hard by Health Canada, essentially identical to the adjacent Ville-Émard (99.5 mg/L), reflecting the uniform Atwater plant St. Lawrence supply in this Sud-Ouest waterfront corridor.

Desmarchais-Crawford's 100.5 mg/L reflects the same Atwater plant supply zone as Ville-Émard and the LaSalle–Verdun south shore corridor, where the St. Lawrence River mainstream carry carries the Ordovician limestone Lowlands' moderate calcium load in the 99–101 mg/L range at this supply intake location. The consistency across this Sud-Ouest waterfront zone suggests a common supply branch through the Atwater plant's southern distribution network.

At 100.5 mg/L, Desmarchais-Crawford residents experience moderate scale deposits in kettles and on tap aerators — descaling every two months is adequate. Hot water tanks operate reliably at this hardness. The Sud-Ouest borough's dense stock of older Montréal-style duplexes and triplexes, many built before 1945, places this neighbourhood in a higher-risk category for lead plumbing; residents are strongly encouraged to consult Montréal's Ministère de l'Environnement-compliant annual water quality report and follow Health Canada lead precautionary testing guidance.