Kamloops Water Hardness & Quality Report (2026)

Kamloops' drinking water is managed by the City of Kamloops, drawing from the Thompson River at the confluence of the North Thompson and South Thompson Rivers via the Kamloops Water Treatment Plant. Water is treated using coagulation, sedimentation, filtration, UV disinfection, and chloramination, fully meeting the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness measures 78 mg/L (4.6 gpg) — classified as moderately hard by Health Canada, moderate for a British Columbia city and reflecting the Thompson Basin's mixed geological character.

Kamloops sits at the convergence of the North and South Thompson Rivers in the semi-arid Interior Plateau of BC. The Thompson watershed drains a vast area of the BC interior, including Tertiary volcanic rock (Columbia River Basalt and related Interior Plateau volcanics), Mesozoic sedimentary and metamorphic terranes, and glaciofluvial valley fill deposits. While the volcanic and metamorphic rocks contribute relatively low mineral loads, the sedimentary units and glaciofluvial deposits in the river valley release moderate amounts of calcium as the river flows through the semi-arid Thompson Basin, building the 78 mg/L hardness measured at Kamloops' intake.

At 78 mg/L, Kamloops residents experience light-to-moderate scale deposits on kettle elements and tap aerators — descaling every two to three months is typical. Hot water tanks operate reliably at this hardness without dedicated scale treatment, though an annual inspection of electric tanks is advisable. Kamloops' moderately hard supply is manageable for most households without a water softener; a scale inhibitor cartridge on the cold water inlet to the hot water tank provides adequate protection for high-efficiency appliances.