Forsyth Reservoir Algal Bloom Monitoring 2019

Warning Advisory

  • Do not swim or water ski in this area.
  • Avoid areas of algae scum when boating.
  • Keep animals away.
  • Do not ingest the water.
  • Clean fish well and discard guts.

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.

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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)