Monroe County, Michigan: drinking water report. Monroe County sits along the western shore of Lake Erie in southeastern Michigan, home to the city of
Monroe County sits along the western shore of Lake Erie in southeastern Michigan, home to the city of Monroe and communities like Luna Pier, Temperance, and Dundee. Most residents get drinking water from the Detroit Water and Sewerage Department system, which draws from Lake Erie and the Detroit River, though some outlying areas rely on private wells. The county's position along major shipping routes and its industrial history create specific water quality challenges that residents should understand.
Monroe County's water supply carries the legacy of Great Lakes industrial contamination. The Detroit River system, which serves most county residents, has shown detectable levels of PFAS compounds in recent testing rounds, consistent with patterns across southeastern Michigan's Lake Erie watershed. While treatment plants remove many contaminants, the source water contains per- and polyfluoroalkyl substances from decades of manufacturing activity upstream, along with agricultural runoff from the county's extensive farmland.
Lead remains a concern in Monroe County's older housing stock. Homes built before 1986 often contain lead service lines or lead solder in plumbing, and the corrosive nature of Great Lakes water can leach lead from these materials when treatment protocols falter. The city of Monroe replaced many service lines following the Flint water crisis, but thousands of homes still have unknown service line materials. County records show elevated lead results in some neighborhoods with housing from the 1940s through 1970s, particularly in the central city areas.
Private well users face different risks. Agricultural areas in Monroe County's western townships show elevated nitrate levels in groundwater testing, typical for regions with intensive row crop farming. Wells near Lake Erie also face contamination risks from harmful algal blooms, which release toxins that standard home treatment systems cannot remove. The county's position at the mouth of the Raisin River means some wells tap into shallow aquifers vulnerable to surface water infiltration during flood events, which occur with increasing frequency.
Test your specific address using local data rather than assuming county-wide averages apply to your tap. Homes built before 1986 should verify service line materials through city records, and private well owners should test annually for bacteria, nitrates, and PFAS. Check your water for current contamination data specific to Monroe County, review our water filter guide for treatment options matched to local contaminants, access your detailed report for testing recommendations, and see the Michigan state page for regulatory context on Great Lakes water quality issues.