Remember: if it's GREEN on top, STOP!




Blue-green algae can be found in many types of waterways such as lakes, ponds, creeks and rivers. Learn to identify blue-green algae and protect yourself by avoiding water that is discolored, or where foam or scum is present.

Photo Credit: Department of Environmental Quality

Photo Credit: Department of Environmental Quality

Though blue-green algae can occur in small amounts not visible to the human eye, large blooms often resemble blue-green paint that has been spilled in the water. Be on the lookout for foam, scum or mats that float on the surface of the water, or a pea soup-like substance.

Mats of blue-green algae can be blown across the lake surface by winds and wash up onto the shore. These shoreline mats can be even more concentrated, and therefore, potentially more toxic than algae blooms in the water.

Blue-green algae blooms can be blue, bright green, brown or even red. As the algae in blooms die, the water may also have an unpleasant odor.


Remember: if it's GREEN on top, STOP!