Algae Control Methods Compared: The Importance of Successful Algae Control for Facilities with UV Disinfection

Algae growth is a problem faced by many wastewater facilities and this problem is not merely one of aesthetics in the case of facilities with UV disinfection. A lack of algae control before the disinfection stage can cause growth in the UV chambers which can lead to breakage of the UV equipment which is costly to replace or merely a decrease in effectiveness of disinfection. In the case of Jewett City, Connecticut there was an increase in “artificial” suspended solids in the final effluent which was caused by an increase in algae growth as well as the proliferation of a dense population of “tiny” snails (Pouch Snails) was occurring in the UV chamber(s) after their switch from Chlorination to UV disinfection. In this specific situation the facility felt as though their current algae control system of brushes was not providing adequate algae control and they chose to do a trial with a spray system which provided their plant with successful algae control. Covering the growth areas with aluminum or fiberglass materials to block sunlight to prevent algae growth has been used by many facilities but the cover material does not block the entire light spectrum and still allows organisms to grow on the surfaces. Chlorine usage along the edge of the trough has also been used although excessive amount chlorine is required and leads to the failure of the concrete aggregate and all rubber components of the UV system.