Petawawa Water Hardness & Quality Report (2026)

Petawawa's drinking water is managed by the Town of Petawawa, drawing from a local lake or reservoir source in Renfrew County — a military community on the north shore of the Ottawa River, home to Canadian Forces Base Petawawa (CFB Petawawa) and 4th Canadian Division, one of Canada's largest and most active army bases, famous for training Canada's combat forces and conducting joint exercises at the Petawawa training areas. Water undergoes coagulation, sedimentation, filtration, UV disinfection, and chloramination, meeting all Guidelines for Canadian Drinking Water Quality (GCDWQ) requirements. Hardness measures 185.5 mg/L (10.8 gpg) — classified as very hard by Health Canada, surprisingly hard for an upper Ottawa Valley Shield community, reflecting the local lake geology of the Renfrew County corridor.

Petawawa sits at the junction of the Canadian Shield and the upper Ottawa Valley sedimentary corridor, where the Ottawa River flows through a mix of Precambrian metamorphic and granite Shield rocks and Paleozoic Ordovician limestone and dolostone outliers that extend into the upper Ottawa Valley. The local lake source at 185.5 mg/L reflects the influence of these carbonate sedimentary units on the Renfrew County watershed — significantly harder than the Ottawa River supply further downstream at Ottawa (116–120 mg/L), reflecting the specific Renfrew County carbonate-influenced lake supply.

At 185.5 mg/L, Petawawa homeowners face regular scale challenges — monthly kettle and showerhead cleaning is typical. Hot water tanks benefit from periodic inspection and flushing. The Town of Petawawa provides water quality information at townofpetawawa.ca. CFB Petawawa manages its own facility water supply. Health Canada lead precautionary guidance applies to older pre-1975 residential properties in the civilian community adjacent to the base.