Troy Water Hardness & Quality Report (2026)

The Troy Water and Sewer Division, part of the City of Troy Public Works Department, provides drinking water to approximately 50,000 residents in Troy, Michigan, located in Oakland County. Water is sourced exclusively from the Great Miami Buried Valley Aquifer, one of the world's largest aquifers estimated to hold 1.5 trillion gallons. The division maintains the distribution system and handles emergencies; no specific treatment plant names are detailed in available reports.

Troy's supply draws from the Great Miami Buried Valley Aquifer, a vast sand and gravel formation associated with the Great Miami River, extending from Logan County to the Ohio River at depths of 30 to 300 feet and widths of 1 to 3 miles. The aquifer is replenished by precipitation, underground sources, and riverbed filtration. Oakland County's geology features limestone and mineral-rich rock layers, where groundwater percolates through and leaches calcium and magnesium — as documented in USGS WRIR 00-4120 — producing a naturally hard water supply.

Hard water in Troy causes scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and increasing energy bills. Glassware spots, dry skin and hair, and reduced soap lathering are common effects. Regular maintenance — including deliming appliances, installing drain screens, and flushing water heaters — is advised; a water softener is recommended for households. Troy's water meets federal legal limits, though contaminants including arsenic, radium, and TTHMs have been flagged as exceeding health advocacy guidelines per EWG analyses, with 7 total contaminants noted and 2 above EPA MCLGs in ZIP 48099.