Updated: January 14, 2021
There is foam on my lake/stream. What is it?
The Michigan Department of Environment, Great Lakes, and Energy (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.
Why does naturally occurring foam appear?
Organic compounds from decomposing plants in the lake/river reach the water's surface, where wind and wave action push them to the shore. The concentration, or build up, of the organic compounds changes the physical nature of the water, making it easier for foam to form. Turbulence and wave action at the beach pushes air into the water with organic compounds, which forms the bubbles in foam. Currents and boats also mix air with the organic compounds in the water to produce naturally occurring foam. Foam can appear year-round on lakes and streams as long as there is open water.
If you find foam on a waterbody, check out the Naturally Occurring Phenomena brochure on tips on how to tell if it is naturally occurring or PFAS foam. Generally, naturally occuring foam:
Why does PFAS foam appear?
Scientists are still studying why and how PFAS foam appears in some lakes and streams and not in others. There are some ways you can distinguish PFAS foam from naturally occurring foam. Generally, PFAS foam:
What should I know about PFAS foam on lakes and rivers?
Foam can have much higher concentrations of PFAS than the waterbody it is found in. Foam can also contain harmful bacteria. Swallowing foam with PFAS could be a risk to your health. MDHHS recommends everyone avoid foam on lakes and rivers impacted by PFAS contamination.
PFAS do not move easily through the skin, but it's always best to rinse off after contact with foam and to bathe or shower after the day's outdoor activities. MDHHS' evaluation of how young children might get foam on them at the beach finds a health risk could exist from repeated, prolonged, whole-body contact with foam containing high amounts of PFAS. Repeated prolonged contact is 3 hours per day, 5 days per week, 3 months of a year, representing a summer season. MDHHS' recommendation to avoid foam with PFAS is protective of everyone, including young children.
MDARD recommends people not allow their pets - especially dogs - to come into contact with or swallow the foam. Dogs could swallow foam collected in their fur when grooming themselves. Dogs should be thoroughly rinsed off with fresh water after contact with foamy water.
What if I see foam on the water I've been recreating in?
Recreating in water containing PFAS is not is not considered harmful because the amount of PFAS is typically low and an accidental swallow of river or lake water is not a health concern.
Are there health advisories related to PFAS foam on lakes/streams?
As a precaution, MDHHS in partnership with local health departments issues PFAS foam recommendations and/or advisories on lakes and streams impacted by PFAS contamination. Foam recommendations and/or advisories have been issued by MDHHS and implemented by local health departments for the following waterbodies:
MDHHS recommends everyone avoid foam on lakes and rivers impacted by PFAS contamination and rinse off the foam after contact.
The amount of PFAS in lake and river water and in foam matters in determining if a health concern exists. MDHHS will continue to evaluate surface water and foam data when it becomes available and will issue further recommendations if necessary.
What can I do if I see foam?
If you suspect PFAS foam has formed on a lake or river, you can either:
What happens after I report suspected PFAS foam on a lake/river to the PEAS number or fill out the foam sighting form?
Because there are no standards for PFAS in foam, EGLE does not sample for foam based on foam sightings. EGLE staff will contact the person who filed the complaint to verify the complaint was received and to ask any follow-up questions. EGLE adds complaints to a database. The complaints are reviewed by staff to help inform sampling done on lakes and streams, which we do to identify sources of PFAS.
If you have health questions about PFAS or foam, call the MDHHS hotline at 800‑648‑6942.
Where has EGLE found PFAS foam?
PFAS contaminated foam was first discovered on Van Etten Lake in July 2017 when a group of high school students participating in the Science, Technology, Engineering and Math (STEM) summer program hosted by Michigan State University and Dow of Midland, encountered foam as they prepared to sample Van Etten Lake surface water for PFAS. Noting the amount of foam and its unusual characteristics (stiffer and whiter than foams that naturally occur on lakes), they decided--with permission from their sponsors--to sample the foam. The foams were contaminated with several PFAS compounds, but most notably with PFOS.
Between 2018 and early 2020 EGLE sampled PFAS foam at Van Etten Lake and Cedar Lake in Oscoda near the former Wurtsmith Air Force Base and on Lake Margrethe in Grayling near Camp Grayling. Foam was also seen and tested at several other locations. The results of this sampling are included in the Surface Water and Foam Results Summary Spreadsheet (.xls). Note that there are no standards for PFAS in foam, so no regulatory actions can be taken due to these results. All results are shared with MDHHS so that they can evaluate the data to determine if a foam advisory is needed. View an interactive table of the results by using the button below.
Is EGLE still sampling for foam?
In 2019 and 2020, the only foam sampling that was conducted was done as a part of an AECOM study intended to do two things:
What is EGLE doing about PFAS foam?
At this time, Michigan is actively tracking PFAS foam appearances on lakes and streams, using foam sightings to guide future surface water and fish contaminant monitoring for PFAS and assist in finding sources of PFAS. EGLE uses existing regulatory programs to address discharges from identified sources that are impacting lakes and streams and may be contributing to the foam. EGLE has also used drones to find groundwater seeps to help understand where the PFAS contaminated foam may be coming from.