The Michigan Department of Environment, Great Lakes, and Energy (EGLE) often receives complaints about the presence of scum on a lake, or that someone has dumped red, bright green, black, or bluish-green paint, oil, or even antifreeze into a lake, river, or stream. This phenomenon is often due to the presence of algae or cyanobacteria rather than the discharge of some type of substance.

EGLE is often contacted with complaints
that someone has dumped paint or a rust-colored substance; or that there is an unnatural colored oil-like sheen in moist areas or in a water body.  Some oil-like films, coatings, and slimes, although they may look bad, are natural phenomena. These phenomena are caused by single- celled organisms called bacteria.

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) often receives complaints claiming that there are gelatinous balls, floating blobs and even “water boogers” some as large as basketballs on the lake shore or in a lake or pond. This phenomenon is due to the presence of bryozoans, also called moss animals, which are not a sign of pollution.

EGLE often receives complaints that “someone discharged laundry detergents into the lake” or that there are suds on the river or stream. This phenomenon is often the result of natural processes, not environmental pollution.  Foam can be formed when the physical characteristics of the water are altered by the presence of organic materials in the water.

Pollen from plants, especially trees like pine and cottonwood, can be found in the late spring and in summer floating on and settling in surface waters. This naturally occurring phenomenon can look like a film on the water or appear as discolored pockets in the water. Pollen has been reported to the EGLE as yellow paint, white paint, oil, scum, and even sludge. This phenomenon is caused by plant pollen that is distributed onto the water where it sticks and collects.

EGLE is often contacted by concerned citizens claiming that someone dumped a white milky substance into the lake. In some lakes, a naturally-occurring phenomenon makes the color of the water change from clear blue to gray or milky white.  This phenomenon is often the result of natural processes, not environmental pollution.  In fact, the cause for this whiting phenomenon is the precipitation (coming out of the water as a solid) of calcium carbonate.