PHOTOS: Harmful algae blooms reported at six Wyoming lakes, reservoirs - Casper, WY Oil City News
Oil City News Logo

PHOTOS: Harmful algae blooms reported at six Wyoming lakes, reservoirs

Saratoga Lake (Wyoming DEQ)

CASPER, Wyo. — The Wyoming Department of Environmental Quality said on Tuesday, Aug. 4 that the recreational use advisories had been issued at a number of Wyoming lakes or reservoirs due to the harmful algae blooms.

Wyoming DEQ said the recreational use advisories had been issued by the Wyoming Department of Health for the following bodies of water:

  • Boysen Reservoir
  • Ocean Lake
  • Saratoga Lake
  • Wheatland Reservoir #3
  • Leazenby Lake

An advisory for Seminoe Reservoir is also listed on the Wyoming DEQ’s “Harmful Cyanobacterial Bloom (HCB) Advisories in Wyoming Waters” webpage. The Wyoming DEQ is also planning to sample Woodruff Narrows Reservoir after receiving a citizen complaint on July 23.

Article continues below...

Leazenby Lake (Hundred Springs Reservoir) (Wyoming DEQ)

“HCBs are also referred to as harmful algal blooms (HABs) since cyanobacteria are commonly known as blue-green algae,” the Wyoming DEQ explains. “The Department of Health issues advisories to inform the public that there may be health risks for people and animals in areas where HCBs occur.”

“Lakes and reservoirs under a recreational use advisory are not closed since HCBs may only be present in certain areas of the waterbody and conditions can change frequently. The advisory will remain in place until the bloom has fully dissipated and cyanotoxin concentrations are below recreational use thresholds identified in Wyoming’s HCB Action Plan, or until the primary recreation season ends on September 30th, whichever comes first.”

Wheatland Reservoir #3 (Wyoming DEQ)

Wyoming DEQ says that people’s reports of possibile blooms or satellite imagery was used to identify potential blooms. The imagery comes from the Cyanobacteria Assessment Network (CyAN).

“The Wyoming Department of Environmental Quality visited the lakes and reservoirs on July 29, 2020 and collected water samples,” Wyoming DEQ add. “Cyanobacteria densities exceeded the 20,000 cells/mL recreational use threshold identified in Wyoming’s HCB Action Plan.”

Ocean Lake (Wyoming DEQ)

“Cyanotoxin results are pending. The Wyoming Department of Health is working directly with resource management agencies to ensure that signs are posted at the lakes and reservoirs. The status of advisories in Wyoming as well as other HCB resources can be found at”

People who encounter possible harmful blooms are provided the following recommendations from the Wyoming DEQ and Wyoming Livestock Board:

  • Avoid contact with water in the vicinity of the bloom, especially in areas where cyanobacteria are dense and form scums.
  • Do not ingest water from the bloom. Boiling, filtration and/or other treatments will not remove toxins.
  • Rinse fish with clean water and eat only the fillet portion.
  • Avoid water spray from the bloom.
  • Do not allow pets or livestock to drink water near the bloom, eat bloom material, or lick fur after contact.
  • If people, pets, or livestock come into contact with a bloom, rinse off with clean water as soon as possible and contact a doctor or veterinarian.
Seminoe Reservoir (Wyoming DEQ)

Questions about health effects and recreational use advisories can be directed to Dr. Karl Musgrave, State Environmental Health Epidemiologist / State Public Health Veterinarian, Wyoming Department of Health, at or (307) 777-5825.

Questions regarding cyanobacteria sampling can be directed to Michael Thomas, Natural Resource Analyst, Wyoming Department of Environmental Quality, at or (307) 777-2073, or Lindsay Patterson, Surface Water Quality Standards Coordinator, Wyoming Department of Environmental Quality, at or (307) 777-7079.

Wyoming DEQ
Boysen Reservoir (Wyoming DEQ)