Pontiac Water Hardness & Quality Report (2026)

The City of Pontiac Water Utility serves approximately 63,357 residents in Pontiac, Oakland County, Michigan. Water is purchased from the North Oakland County Water Authority (NOCWA), which sources it from the Great Lakes Water Authority (GLWA). The supply comes from Lake Huron via the Lake Huron Water Treatment Plant in Port Huron, employing conventional treatment processes including coagulation, sedimentation, filtration, and chlorination. The utility operates under oversight from the Oakland County Water Resources Commissioner, ensuring compliance with federal and state standards.

The Lake Huron watershed feeds Pontiac's supply as part of the expansive Great Lakes-St. Lawrence River Basin, spanning glaciated terrains of the Midwest. Paleozoic sedimentary rocks dominate, with Devonian-age limestone and dolomite formations prevalent in the Michigan Basin, leaching calcium and magnesium into surface waters. Glacial till and moraines overlay these strata, influencing runoff chemistry through carbonate dissolution. This geology imparts a hard character to the treated supply from Lake Huron.

Moderately hard water in Pontiac leads to moderate scale buildup in pipes, water heaters, and dishwashers, reducing efficiency and lifespan. Affected appliances include washing machines, coffee makers, and faucets, where limescale causes spotting on glassware and drier skin from soap scum. Regular vinegar descaling, low-flow aerators, and periodic flushing help mitigate issues. A water softener is recommended for households to improve lathering, extend appliance life, and cut detergent use. Pontiac's water meets federal and state requirements, with conventional treatment using chlorine disinfection and a quality score of 80/100.