Forsyth Reservoir Algal Bloom Monitoring 2019

Report a Bloom

24-Hour DEQ Environment Incidents Line: (801) 536-4123

Call Utah Poison Control Center

If you believe you or your pet have been exposed to a harmful algal bloom, call (800) 222-1222.

Get BloomWatch App

Help us track cyanobacteria blooms with your smartphone. Go to cyanos.org for more info.

Update November 8, 2019

The Central Utah Public Health Department (CUPHD) has removed the Warning Advisory on Forsyth Reservoir.

The close of the monitoring season and removal of advisories doesn’t mean HABs are no longer present, but rather that monitoring data won’t be collected during the colder months to verify their presence. HABs can persist throughout the fall and winter and can pose a potential threat to humans and pets. It’s important for recreators to recognize the signs of a bloom and take appropriate precautions.

Recreators are advised to stay out of the water and avoid any contact with water or scum if they suspect a harmful algal bloom. Hunters and fishers should clean waterfowl and fish well and discard all guts.


Update October 29, 2019

Forsyth Reservoir, October 10, 2019

Toxin test results received from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) at the boat ramp at Forsyth Reservoir on October 10, 2019, showed anatoxin-a and microcystin levels well below the recreation health-based threshold for a Warning Advisory. Cyanobacteria cell-count concentration results are pending from PhycoTech.

A Warning Advisory indicates a moderate relative probability of acute health risk, cell-count density of 20,000 – 10 million cells per milliliter (cells/ml), microcystin levels of 4-2,000 micrograms per liter (µg/L), or anatoxin-a levels above non-detect.

Forsyth Reservoir remains under a Warning Advisory.

Data Summary

  • Sample date: October 10, 2019
  • Sample type: Elbow-depth integrated composite sample
  • Microcystin: <2.0 micrograms per liter (µg/L)
  • Anatoxin-a: <0.10 µg/L

Update September 16, 2019

Forsyth Reservoir, September 11, 2019

The Central Utah Public Health Department (CUPHD) issued a Warning Advisory for Forsyth Reservoir on September 16, 2019.

Cyanobacteria cell count concentrations for samples collected by the Division of Water Quality (DWQ) at the boat launch on September 11, 2019, exceeded the recreation health-based threshold for a Warning Advisory. Aphanizomenon was the primary taxon in the samples. Toxin test results received from the Utah Public Health Lab (UPHL) showed anatoxin-a levels exceeding the recreation health-based threshold for a Warning Advisory. Microcystin levels were below the advisory threshold.

The DWQ monitoring crew observed visible cyanobacteria that resembled green grass clippings, isolated clumps of bloom material, and cyanobacteria resembling spherical nodules. These were consistent throughout the water column.

A Warning Advisory indicates a moderate relative probability of acute health risk, cell-count density of 20,000 – 10 million cells per milliliter (cells/ml), microcystin levels of 4-2,000 micrograms per liter (µg/L), or anatoxin-a levels above non-detect.

Data Summary

  • Sample type: Elbow-depth integrated composite sample
  • Sample date: September 11, 2019
  • Microcystin: 2.2 micrograms per liter (µg/L)
  • Anatoxin-a: 0.12 µg/L
  • Cyanobacteria cell counts: 41,790 cells per milliliter (cells/mL)