Well Water in Oakland County, Michigan

Oakland County · Population ~1.27 million (county); northern townships on wells · Aquifer: Glacial Drift

Hardness: 250-500+ PPM — Hard to Extremely Hard

Oakland County is Michigan's second most populous county, but its northern townships — Holly, Oxford, Orion, Brandon, Independence — are largely rural and well-dependent. The suburban-rural boundary creates a unique situation: dense development with individual wells and septic systems, and glacial geology that produces some of the hardest water in Southeast Michigan.

Extremely Hard Water

Northern Oakland County is known for extremely hard water. Wells commonly test between 250 and 500+ PPM — well into the "very hard" to "extremely hard" range. This is a direct result of the glacial geology: water passes through calcium and magnesium-rich glacial till on its way to the aquifer.

Hard water destroys water heaters (reducing lifespan by years), clogs pipes with scale, leaves white deposits on everything, and makes soap nearly useless. A water softener is essentially mandatory for northern Oakland County homeowners.

PFAS Contamination

Oakland County has multiple confirmed PFAS contamination sites. The chemicals have been found in groundwater near former industrial facilities, airports, and fire training areas where PFAS-containing foam was used. The Oakland County Health Division has been actively investigating and testing private wells in affected areas.

If you receive a notice from the health department about PFAS in your area, take it seriously and get tested. See our PFAS guide for more information.

Arsenic and Radon

Arsenic occurs naturally in Oakland County's glacial deposits, and some wells exceed the 10 ppb EPA limit. Radon — a radioactive gas that dissolves in groundwater — is also a concern in parts of the county. Radon in water is released when you shower, cook, or run water, contributing to indoor air radon levels. It's a known cause of lung cancer.

Both are invisible and undetectable without testing. See our arsenic guide for details on arsenic.

Testing Priorities

Northern Oakland County well owners should test annually for bacteria and nitrates. Test at least once for arsenic, radon, hardness, iron, manganese, and pH. Consider a PFAS panel, especially if you're near known contamination sites or within a few miles of an airport or fire station.

See our testing guide for certified labs and costs.

Every well is different. Two wells on the same street can produce completely different water. The data on this page reflects documented conditions in the Oakland County area, but the only way to know what's in your water is to test it.

Sources

  • Michigan EGLE — Wellogic Database, Oakland County Extract
  • Oakland County Health Division — Private Well Testing Program
  • USGS — Radon in Michigan Groundwater
  • Michigan PFAS Action Response Team — Oakland County Investigation Sites