Public Health Watch
Harmful algal bloom (HAB) Watch serves as an advisory to notify the public that hazardous conditions are possible or present. A Watch is issued based on visual confirmation of a bloom, microcystin toxin concentrations, and/or blue-green algae cell counts. Visual confirmation is determined by qualified KDHE staff working with lake managers and/or managing agencies using jar tests, photographs, or site visits. A Watch is issued if it has been analytically determined that the microcystin toxin concentration in the water is greater than 4 µg/L but less than or equal to 8 µg/L and/or blue-green algae cell counts are greater than 80,000 cells/mL but less than or equal to 250,000 cells/mL.
The following guidelines are recommended for a public health watch:
- Harmful algae are possible and may be present
- Signage will be posted at all public access locations
- Water may be unsafe for humans/animals
- Avoid areas of algae accumulation, and do not let people/pets eat dried algae or drink contaminated water
- Swimming, wading, skiing, and jet skiing are discouraged near-visible blooms
- Boating and fishing are safe. However, inhalation of the spray may affect some individuals. Avoid direct contact with water, and wash with clean water after any contact.
- Clean fish well with potable water, and eat fillet portions only
Public Health Warning
Harmful algal bloom (HAB) Warning serves as an advisory to notify the public that conditions are expected to be unsafe for human exposure. A warning will be issued if it has been analytically determined that the microcystin toxin concentrations are greater than 8 µg/L but less than or equal to 2,000 µg/L and/or blue-green algae cell counts are greater than 250,000 cells/mL but less than or equal to 10,000,000 cells/mL. If there is verification of significant blue-green algae surfaces scum present, a "Warning" may be issued based on visual confirmation prior to sample collection.
The following guidelines are recommended for a public health warning:
- Harmful algae are expected or present
- All of the recommendations of the Public Health Watch remain in effect, with the following addition:
- All contact with water, including fishing and boating, should be avoided
Public Health Hazard
Harmful Algal Bloom (HAB) Lake/Beach Closure notifies the public that extreme conditions exist. At this level, it has been analytically determined that the microcystin toxin concentration is greater than 2,000 µg/L and/or cyanobacterial cell count is greater than 10,000,000 cells/mL. It is recommended that either a portion of the lake, entire lake, or zone, be closed and in some cases, the adjacent land (e.g., approximately 100 feet from the shoreline) be closed to the public. Actual setback distances will be determined on a site-specific basis, if necessary. When partial closures (i.e., beach or cove) are issued, the remaining lake or zone area will carry a warning status.
- Harmful algae are present and extreme conditions exist
- All of the recommendations of the Public Health Watch and Warning remain in effect, with the following addition:
- Is recommended that either portion of the lake, the entire lake, or zone, be closed. If necessary - close adjacent land up to 100 ft from the shoreline.