AWWA ACE65420

While prevention of cyanobacterial occurrences at the source is not always possible, cyanobacteria passage through the treatment plant could be prevented or at least reduced to a level that does not pose water quality threats. Can conventional settling processes provide adequate protection against the cyanobacteria passage? Can membranes provide an absolute barrier to cyanobacteria? How serious is the passage of cyanobacteria through conventional dual-media filters? What is the proper chemical pretreatment required in controlling cyanobacterial passage? Knowing the answers to these questions would greatly assist operators in managing emergency situations related to cyanobacterial blooms. This paper summarizes possible types of cyanobacterial nuisances with respect to water treatment, prevalence in selected lake sources, and removal capabilities of these nuisance organisms by various water treatment processes, particularly, clarification and filtration. Includes 5 references, tables, figures.