If you’ve been worried about foam and a red cast in some of the branches of the Kishwaukee and Rock Rivers,you can relax.
It is not, according to the Illinois EPA, due to some unreported industrial or agricultural release. The EPA says investigations have determined that these are rare but natural occurrences. In this case, weather and water conditions in northwestern Illinois have been just right to promote growth of a particular type of algae.
While typically seen only a few times each decade, this episode has arrived early due to the warm weather, the low river levels and warmer water.
The agency’s findings indicate these results are characteristic of this type of algae. As biological organisms degrade, they secrete a protein compound to facilitate biochemical reactions. That’s what causes the visible foam.
The Illinois EPA expects more situations like this to occur until the weather and precipitation pattern changes. They are likely to become less noticeable and ultimately disappear as the weather cools in early fall and when rainfall increases.