Blue-green algae bloom in Cheyenne’s Sloans Lake

BOPU 8-31-21

The Wyoming Department of Health has issued a warning about the rising dangers of blue-green algae blooms in Sloans Lake which is used for recreational and irrigation purposes only and not used for the City of Cheyenne’s drinking water supply. The Cheyenne Board of Public Utilities (BOPU) will work to combat any blue-green algae blooms through continuous water quality monitoring and any necessary treatment. 

Blue-green algae can form harmful blooms in slow-moving water during late summer months when water temperatures increase. These blooms are considered harmful due to the production of toxins and other irritants which can pose a risk to humans, pets, livestock, and wildlife.

The BOPU is asking residents to follow these recommendations:

  • Avoid contact with water in the vicinity of a bloom, especially in areas where cyanobacteria may be dense and form a residue.
  • Do not ingest water where a bloom may be present. Boiling, using filtration, and/or other treatments will not remove toxins.
  • Rinse fish with clean water and eat only the fillet portion.
  • Avoid any water spray-off where a bloom may be present.
  • Do not allow pets or livestock to drink water near a bloom, eat bloom material or lick fur after contact with a bloom.
  • If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible.

For more information about blue-green algae, please visit