 The Washtenaw County Health Department and Michigan Department of Health and Human Services monitors the water quality and issues advisories when the bacteria levels in the water may pose a health threat.Most algal blooms are green algae and pose no threat, but accumulating cyanobacteria and perfluorooctanesulfonatecan (PFOS) can result in harmful algal blooms that can have negative health affects.When this bacteria is present, prolonged contact with the water is not advised, although occasional contact with PFOS is not considered a health concern.