Choctaw Lake Water Quality
We tested the lake microcystin concentration on June 11, and it was 2.3 ppb. As a result, the lake will be treated this week with copper sulfate. While levels are in safe ranges now, microcystin concentrations grow in the summer months so we are aggressively fighting it to keep our lake water safe.
Treatment is scheduled to begin at 6:00AM Thursday morning. Estimated completion is 9:00AM. We recommend staying off the lake until 5:00PM Thursday to allow for the treatment to fully dilute. After that time, all normal water operations can safely resume.
The state of Ohio regularly monitors microcystin in state park lakes, but not private lakes. At those lakes, public health advisories are issued at two levels of advisories for microcystin concentration, and we are far below these levels.
Those advisories are:
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.
Note: “Blue-green algae” is often used to refer to microcystin. “Blue-green algae” is actually cyanobacteria, not algae. Cyanobacteria are comprised of several species of organisms, one of which is microcystin.