The latest water quality samples taken by the Ohio EPA on Grand Lake St. Marys indicate that the level of toxic microcystin in the lake is at leat 50 parts ber billion at West Beach, the Celina drinking water intake, and the St. Marys Boat Club Launch Ramp.  That level is two and a half times more than the safe recreational contact level of 2o parts ber billion established by the World Health Organization.

See the latest Ohio EPA water sampling data for Grand Lake St. Marys

All about harmful algal blooms

Grand Lake St. Marys algal toxin fact sheet