Payson Lakes Algal Bloom Monitoring 2019

McClellan Lake, Box Lake: Warning

Warning Advisory

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

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.

Visit the 2019 Photo Gallery

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

Update August 5, 2019

Box Lake, July 25, 2019

The Utah County Health Department (UCHD) issued a Warning Advisory on August 5, 2019, for Box Lake in the Payson Lakes Complex. UCHD placed advisory signs at the lake this afternoon.

The Division of Water Quality (DWQ) collected routine samples at Box Lake on July 25, 2019. Toxin test results were detect for anatoxin-a, and cyanobacteria cell-count concentrations were approximately 169,000 cells per milliliter (cells/mL), both of which exceed the recreation health-based threshold for a Warning Advisory.

The monitoring crew observed cyanobacteria resembling grass clippings throughout the water column and concentrated along the northern shore. There was evidence of a past bloom on the lakeshore.

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: July 25, 2019
  • Microcystin: <0.10 micrograms per liter (µg/L)
  • Anatoxin-a: 0.101 µg/L
  • Cell Counts: 169,204 cells per milliliter (cells/mL)

Update July 23, 2019: McClellan Lake

The Division of Water Quality (DWQ) returned to the Payson Lakes complex and collected elbow-depth integrated composite samples at McClellan Lake on July 9, 2019 and July 16, 2019.

Results from the July 9, 2019, and July 16, 2019, sampling runs showed cyanobacteria cell counts lower than the original June 24, 2019, sample. Toxin results from July 16, 2019, indicated the presence of the neurotoxin anatoxin-a. Detection of anatoxin-a in a waterbody exceeds the recreation health-based threshold for a Warning Advisory.

The Payson Lakes complex will remain under a Warning Advisory.

July 9, 2019

  • Toxin test results:<0.10 micrograms per liter (µg/L) of anatoxin-a: 0.12 µg/L of microcystin
  • Cyanobacteria cell-count concentrations: surface sample: 3,497 cells per milliliter (cells/mL); integrated depth sample: 18, 777 cells/mL

July 16, 2019

  • Toxin test results: 0.10 micrograms per liter (µg/L) of anatoxin-a; >0.10 µg/L of microcystin
  • Cyanobacteria cell-count concentrations: integrated depth sample: 5,257 cells/mL
  • With anatoxin-a levels detected, the lake remains on a Warning Advisory.
McClellan Lake, July 16, 2019

McClellan Lake, July 16, 2019


Update July 9, 2019: McClellan Lake

The Utah County Health Department UCHD) has issued a Warning Advisory for McClellan Lake after cyanobacteria cell-count concentrations exceeded recreation health-based levels.

The Division of Water Quality (DWQ) collected elbow-depth integrated composite samples at McClellan Lake, a small lake in the Payson Lakes complex, on June 24, 2019. The monitoring crew observed clumps of green filamentous algae along the shore but no obvious cyanobacteria blooms. Monitors submitted samples to the Utah Public Health Lab and PhycoTech for further analysis.
Cyanobacteria cell-count concentration results received from PhycoTech on July 5, 2019, showed cell-count densities of 54,343 cells per milliliter (mL), which exceeds the health-based threshold for a Warning Advisory.

Toxin test results for microcystins of <0.10 micrograms per liter (µg/L) were well below the recreation health-based threshold for an advisory. However, the dominant taxon present in the sample, Aphanizomenon gracile, Sphaerospermopsis, and Chrysosporum, can produce microcystin and anatoxin-a.

DWQ monitoring crews will sample McClellan Lake. Big East Lake, and Box Lake later this week.

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.