Have you ever seen foam on the surface of the Russian River and wonder if it’s pollution? Here’s what you need to know:
The color and smell of the foam will tell you if it’s pollution or naturally occurring foam. Bright white foam that might have a sweet smell or perfume fragrance is pollution and usually from soaps suds from car washing or other pollution. If the foam has a slight brownish color it’s naturally occurring dissolved organic carbon from degradation of organic material like leaves that fall into the river. The organic decomposition in water produces surfactants that break surface tension which allows air to easily mix with water and create bubbles, the current moves the bubbles to congregate into foam. We call natural foam biofoam and it is harmless and usually dissipates when sunlight hits it.
Of course detergents and soap suds belong in our showers or car washes not in the street gutters where it runs into storm drains and directly into creeks. To protect your local creek do not empty soap suds from washing anything into the street but dump it down the drain in your house or on to a grassy area where it usually does no harm – that will keep your creek free from foam pollution!