Updated: April 2020
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 occur naturally or 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 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.
How can I tell if the foam on my lake/stream is natural or from PFAS or some other contaminant?
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 occurring foam:
Is PFAS foam harmful?
MDHHS recommends you avoid foam on lakes and rivers impacted by a PFAS contamination site. Foam on these lakes and rivers can have much higher amounts of PFAS than the water. Swallowing foam with PFAS could be a risk to your health. Learn more about known PFAS sites.
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. There is no new scientific information on how PFAS moves through the skin. However, 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. To learn more about PFAS foam and health, read the MDHHS Foam and PFAS fact sheet.
The Michigan Department of Agriculture and Rural Development recommends that 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.
Are there health advisories related to PFAS foam on lakes/streams?
As a precaution, some local health departments and MDHHS have issued health advisories regarding PFAS foam on lakes and streams. As of June 2019, health advisories have been issued by local health departments and/or MDHHS for the following waterbodies. These advisories are in place indefinitely:
If you suspect the foam is not naturally occurring you can either:
Call the 24-hour Pollution Emergency Alert (PEAS) hotline at 800-292-4706 to report the foam. Helpful information to be provide when completing the complaint form, or if you call the PEAS line, include:
PFAS contaminated foam was first discovered on the shore of 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 the foam as they prepared to sample Van Etten Lake surface water for PFAS contamination. Noting the amount of foam and its unusual characteristics (stiffer and whiter than protein 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.
EGLE subsequently found PFAS foam at several other sites. PFAS foam has frequently been found on Van Etten Lake and Cedar Lake in Oscoda near the former Wurtsmith Air Force Base and on Lake Margrethe in Grayling near Camp Grayling. It has also been seen and tested on the Thunder Bay River in Alpena; the Rogue River in Rockford near the dam; on the Thornapple River in Grand Rapids; and on the Huron River at several locations.
EGLE has received reports of foam at various other locations throughout the state.
What is EGLE doing about PFAS foam?
At this time, it is believed Michigan is one of only a few states aware of PFAS foam appearing on lakes and streams. We use foam sightings to assist us in finding sources of PFAS. See, PFAS foam can occur on surface waters either because PFAS was released into the waterbody (for example, if fire-fighting foam with PFAS in it was used to put out a fire and the foam got into the nearby surface water), or the PFAS was introduced from contaminated groundwater slowly entering the body of water. Finding groundwater seeps is an important step to understanding where the PFAS contaminated foam may be coming from.
EGLE was also the first in the nation to use drones equipped with infrared cameras to search for locations where suspected PFAS-contaminated groundwater is seeping into a lake. In 2018, two drone flights occurred: one on Lake Margrethe (September 2018), and one on Van Etten Lake (November 2018). The drone imagery at Van Etten was used to determine that contaminated groundwater from the Wurtsmith Air Force Base was going into Van Etten Lake, which was confirmed by sampling groundwater seeps. Read more about EGLE's use of drones.
What happens after I report PFAS foam on my lake to the PEAS number or fill out the form?
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.
For more information about PFAS, please visit the Frequently Asked Questions.