If you receive a water bill, your water
comes from a public water supply.
If you do not pay for your water, you
are on a private well. Approximately
75% of Michigan residents get water
from a public water supply.
Approximately 25% are on private
wells.
Public water supplies may be large, like the Great Lakes Water Authority, which serves 3.7 million residents, or they may be smaller, such as a supply serving a manufactured housing community. Some public water supplies get water from groundwater, some from surface waters (lakes or rivers) and some blend groundwater and surface water sources together. To ensure the drinking water for the largest portion of Michigan residents was tested for PFAS, beginning in April 2018, the Michigan Department of Environment, Great Lakes, and Energy (EGLE) implemented a statewide program to test Michigan's public water supplies across several phases of sampling.
The United States Environmental Protection Agency (USEPA) set a Lifetime Health Advisory (LHA) level for two PFAS in drinking water: perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) . The LHA level is 70 parts per trillion (ppt, equal to 70 ng/L) for PFOA and PFOS combined, or individually if only levels for other PFAS chemicals. The State of Michigan is using 70 ppt for decision making purposes.
Only three supplies have been found to have PFOS+PFOA over the USEPA LHA:
What’s next?
Sampling of Public Water Supplies, Childcares/MI Head Starts, and Tribal systems.
More InformationSampling of approximately 750 Type II noncommunity water supplies.
More InformationMonthly surface water system monitoring data table.
More InformationQuarterly monitoring data table.
More Information