Cautionary Note:
Excessive foam in an aeration basin causes a variety of problems. A foam blanket can interfere with oxygen uptake of the microorganisms and hinder BOD reduction. Foam can also cause a biological floc to float, producing sludge that will not settle in the final clarifier. Safety and aesthetic problems occur when wind blows foam across parking lots, highways or neighboring locations. Foam in plant outfalls is an aesthetic unpleasant situation.