Our lake’s microcystin concentration from a sample taken on July 10 was 0.75 parts per billion (ppb). Yeah! That’s great news! And the recent heavy rains likely caused an even lower microcystin concentration.
Ohio EPA requires advisories at two levels of microcystin, and we are far below those levels.
Recreational Public Health Advisory: A sign is posted on beaches when toxin levels exceed 6 ppb warning that an algal bloom is present and/or algal toxins have been detected. Swimming or wading is not recommended for children, pregnant or nursing women, those with certain medical conditions, and pets.
Elevated Recreational Public Health Advisory: A sign is posted on beaches when toxin levels exceed 20 ppb warning that all contact with the water should be avoided and algal toxins at unsafe levels have been detected.
(As an aside, 1.0 ppb is analogous to one sheet in a roll of toilet paper stretching from New York to London or one second of time in 32 years.)