Farmington Hills Water Hardness & Quality Report (2026)

Farmington Hills receives its drinking water from the Great Lakes Water Authority (GLWA), which manages the regional system under a lease with the City of Detroit. The utility draws raw water from the Detroit River and Lake Huron, treating it at the Lake Huron Water Treatment Plant in the lower Lake Huron watershed. Water is pumped through 790 miles of transmission lines, delivering 650 million to 1.3 billion gallons daily to metropolitan Detroit-area communities, including Farmington Hills in Oakland County, Michigan. The 2024 Drinking Water Quality Report confirms the city's water meets all federal and state standards.

The watershed encompasses the St. Clair-Detroit River system connecting Lake Huron to Lake St. Clair and Lake Erie, with intakes in mineral-rich glacial till and Paleozoic limestone terrains. Devonian-age carbonate rocks — limestone and dolomite — underlie much of the basin, leaching calcium and magnesium into the surface waters during transit through limestone-influenced drainage. Precambrian bedrock underlies these Paleozoic formations, while Pleistocene glacial deposits further channel mineral-rich water toward intake points, collectively imparting a hard character to the supply.

At moderately hard levels, the water promotes moderate scale buildup in pipes, water heaters, dishwashers, boilers, washing machines, and faucets, causing spotting and higher energy use. Regular maintenance including vinegar descaling, installing drain screens, and flushing heaters is recommended. A water softener is advised for households noticing soap scum, dry skin, or spots on glassware to extend appliance life and improve lathering. Fluoride is added for dental health. Chromium (hexavalent) has been detected above health guidelines per analyses; the utility reports lead and copper compliance through multi-stage treatment and filtration at GLWA plants.