Skip to main content

Sampling in Lakes and Streams

A person standing on the edge of a dock into a lake

Sampling in Lakes and Streams

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) Water Resources Division (WRD) collects surface water samples from Michigan’s lakes and streams for PFAS analysis to identify potential sources of contamination. EGLE and the Michigan Department of Natural Resource (MDNR) collect fish for contaminant analysis to assist the Michigan Department of Health and Human Services (MDHHS) in identifying where fish consumption advisories are needed.

The results of the WRD’s monitoring efforts are shared within MPART’s Surface Water Workgroup, which consists of representatives from EGLE, MDHHS, and MDNR. These results play a large role in the identification of sources causing elevated fish, surface water, point source, and/or drinking water PFAS concentrations and the development of public health advisories.  As new discharges and detections come to light, EGLE’s WRD mobilizes staff to collect surface water and fish tissue samples for contaminant analysis. The WRD staff also work with the responsible entities to reduce usage of PFAS and treat PFAS on-site.

EGLE first analyzed PFAS in surface water in 2001 when 21 Michigan streams were sampled for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).  The study found varying levels of both substances, but the concentrations were not considered to be a problem based on what was known about PFAS at the time.

In 2011, EGLE WRD found concentrations of PFOS as high as 9,580 parts per billion (ppb) in fish collected near Oscoda. This sampling effort resulted in MDHHS issuing a “Do Not Eat” advisory for all fish species from Clark’s Marsh and several species of fish from the Au Sable River near the former Wurtsmith Air Force Base in Oscoda. Visit MDHHS’ Eat Safe Fish webpage for more information regarding these advisories.

The discovery of the high levels of PFOS in the Oscoda area fish prompted a more intensive statewide sampling of Michigan’s large rivers in 2013 and 2014.  The results of this reconnaissance study indicated several rivers had detectable levels of PFOS in surface water and/or fish tissue. 

EGLE's WRD has since conducted numerous targeted PFAS sampling efforts to monitor rivers and lakes used as drinking water sources and to help identify sources of PFAS in other watersheds, with staff sampling 4-5 watersheds per year.  For more information on these efforts, please visit the MPART Surface Water Workgroup page.

An EGLE staff person sitting on a boat on a lake with sampling equipment

Surface Water Workgroup

The Surface Water Workgroup uses surface water and fish tissue samples to locate sources of PFAS contamination, evaluate treatment to reduce PFAS levels, and develop fish consumption advisories.

Learn about surface water and fish monitoring efforts
A strikingly vibrant bluegill fish held in a hand. The fish is a medley of bright yellow, green, and aqua with a dark navy spot behind its gills.

PFOS in fish

PFAS is the family of per- and polyfluoroalkyl substances. One of the most commonly detected substances is perfluorooctanesulfonic acid (PFOS), in part because it bioaccumulates, or builds up, in fish. 

Learn more about PFOS in fish
A large pile of fluffy white PFAS foam on a sandy beach

Foam on lakes and streams

EGLE often receives complaints about foam on a river or lake. This foam can be naturally occurring foam or foam formed because of environmental pollution. There are many things that can be introduced into a lake or stream that may cause foam to form.

Learn about PFAS foam on lakes and streams

Watersheds sampled for PFAS