The Department of Environmental Quality has now confirmed a toxic cyanobacterial bloom in Wheatland Reservoir 3, meaning that Albany County now has three of the eight bodies of water that the DEQ has issued cyanobacterial bloom advisories for. Four of the blooms have been confirmed since just Wednesday.
Such cyanobacterial blooms are most commonly known as blue-green algae. Despite being called “algae,” cyanobacteria are not related to the broad group of photosynthesizing organisms typically classified as algae.
A water sample taken near the boat ramp of Wheatland Reservoir 3 found 3 million cyanobacteria cells per milliliter.
The threshold for a DEQ advisory is 20,000 cells/mL
According to a Wednesday press release, the Wyoming Department of Health is currently working with Wyoming Game and Fish and the Wheatland Irrigation District to post advisory signs at the reservoir.
Water bodies under a recreation use advisory are not closed because the blooms might only be present in certain areas.
The state department has two other active advisories for the county: One of Leazenby Lake, issued July 25, and one issued for Toltec Reservoir, issued Aug. 5.
An advisory was issued for Leazenby Lake was issued after two dogs died there.
As with Toltec Reservoir, the dominant cyanobacteria in Wheatland Reservoir 3 was aphanizomenon.
When Toltec Reservoir was sampled near the boat launch, DEQ found 699,081 cells per milliliter of cyanobacteria. Toltec Reservoir lies on the far north end of Albany County, on the southern edge of the Laramie Range.
When DEQ sampled Leazenby Lake, which lies south of Laramie, staff found 4.3 million cells per milliliter. The dominant cyanobacteria in Leazenby was phormidium.
DEQ advises recreationists to avoid contact with water in the vicinity of the bloom and to not let animals or livestock to come into contact with the water. Boiling, filtration and other treatments will not remove the toxins.
In 2018, cyanobacteria advisories were issued in August for all three Wheatland reservoirs.
While some cyanobacteria are common in standing bodies of water, toxic concentrations occur, typically, when there’s an overabundance of nutrients in water — often from agricultural use or other runoff.
The algae blooms have been widespread across Wyoming in recent years, and the DEQ has put an increased emphasis on testing and awareness.
Combatting cyanobacteria would require determining where the nutrients are coming from.
However, DEQ Natural Resource Analyst Michael Thomas said he didn’t know what specific nutrients are present in Wheatland Reservoir 3 to cause the blooms.
When the DEQ collects samples to confirm cyanobacteria, the agency doesn’t currently conduct “paired sampling” to identify the nutrients causing those blooms, Thomas said.
The cyanobacterial blooms deplete oxygen levels and are toxic to humans and animals in high concentrations.
Two years ago, a cyanobacteria bloom in Johnson County killed about 50 head of cattle.
Health effects in humans include rashes, itching, numbness, nausea, fatigue, disorientation, abdominal pain, vomiting and diarrhea.
After a bloom dies, the microbes that consume the cyanobacteria deplete more oxygen and can lead to a die-off of fish.
In May 2018, the DEQ produced a guide of standard operating procedures for collecting cyanobacteria samples. The agency now works with the Wyoming Department of Health to post signs at contaminated waters and issue public notices.
Up-to-date information about Wyoming’s cyanobacterial blooms is available at WyoHCBs.org.