It is a natural process that has been going on for a long time. All lakes contain organic matter, such as algae, rooted aquatic plants and leaves. When this organic matter decomposes through natural bacterial action, it releases cellular products to the water, which form a surfactant, or surface agent. A surfactant simply lessens the surface tension of water, making it susceptible to foaming. When the wind blows, the waves on the lake agitate this surface agent, thus transforming it into a sudsy white foam.
Natural foam is most noticeable along beaches exposed to the prevailing wind direction.
When the foam reaches the shoreline, it tends to form a loose line where it mixes with tiny pieces of organic matter, which act as a binding agent and give it stability. Foam on the surface waters is a harmless by-product of our lakes. Its chemical makeup is 99 percent air and water, combined with one per cent or less surfactant. Back in the 1950's manufacturers of laundry detergents marketed a type of product that was highly resistant to chemical breakdown. As a result, there was a foaming problem in the vicinity of all sewage treatment plant outfalls.