Laurentian Hills Water Hardness & Quality Report (2026)

The Chalk River Drinking Water System, managed by the Township of Laurentian Hills in Renfrew County, Ontario, draws all its water from Corry Lake. This reservoir serves as the sole source for the community, including Chalk River itself. The water undergoes treatment at the municipal drinking water treatment plant before distribution to homes and businesses within the township's service area. Official records indicate no other sources, such as rivers or groundwater wells, are utilized for this supply. Corry Lake is situated within the Ottawa River watershed, which eventually flows into the St. Lawrence River basin.

The geology beneath Corry Lake is a mix of ancient Precambrian Canadian Shield granites and gneisses, overlaid by Ordovician limestone and dolostone. These rock types are common across eastern Ontario and are rich in minerals. As water flows over and through these formations, it naturally picks up calcium and magnesium. This process, often exacerbated by thin soils and glacial deposits, results in a consistently hard water supply, typical for areas influenced by limestone bedrock.

Homeowners will likely notice scale buildup in appliances that use hot water. This mineral deposit reduces the efficiency of water heaters and dishwashers, potentially shortening their lifespan. You might also see stains on fixtures and find that cleaning requires more soap or detergent. Kettles and boilers are especially prone to accumulating scale on their heating elements, leading to increased energy consumption. While regular descaling with vinegar and using detergent boosters can help, installing a whole-house water softener is often recommended to protect plumbing and improve cleaning performance.