Payson Lakes Algal Bloom Monitoring 2019

Big East Lake, McClellan Lake, Box Lake: Warning

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.

Visit the 2019 Photo Gallery

Get BloomWatch App

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

Update September 16, 2019: Box Lake and McClellan Lake

Toxin test results received from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) at the access points at Box Lake and McClellan Lake on September 10, 2019, showed anatoxin-a levels exceeding the recreation health-based threshold for a Warning Advisory. Microcystin levels and cyanobacteria cell-count concentrations results are pending.

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.

Box Lake and McClellan Lake remain under a Warning Advisory.

Data Summary

Box Lake

  • Sample date: September 10, 2019
  • Sample type: Elbow-depth integrated composite sample
  • Anatoxin-a: 0.13 µg/L

McClellan Lake

  • Sample date: September 10, 2019
  • Sample type: Elbow-depth integrated composite sample
  • Anatoxin-a: 0.11 µg/L

Update September 16, 2019: Big East Lake

Big East Lake, September 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 beach at Big East Lake on September 10, 2019, showed anatoxin-a levels exceeding the recreation health-based threshold for a Warning Advisory. Microcystin levels and cyanobacteria cell count concentrations were well below the advisory threshold. The primary taxon was Gloetrichia.

The DWQ monitoring crew observed visible cyanobacteria resembling cylindrical nodules. Samples were taken as a follow-up to a citizen call. The cyanobacteria were slightly more concentrated along the North shore.

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.

Big East Lake remains on a Warning Advisory.

Data Summary

Elbow-depth integrated composite sample

  • Sample date: September 10, 2019
  • Microcystin: 0.33 micrograms per liter (µg/L)
  • Anatoxin-a: 0.13 µg/L
  • Cyanobacteria cell counts: 3,688 cells per milliliter (cells/mL)

Update September 6, 2019: Box and McClellan Lakes

Cyanobacterial cell-count concentration and toxin test results received by the Division of Environmental Quality (DWQ) for samples collected on August 29, 2019, at the access points at Box Lake and McClellan Lake were well below the recreation health-based threshold for a Warning Advisory. Cell counts have dropped significantly over the past few months.

DWQ is now running new dilution curves for its enzyme-linked immunosorbent assay (ELISA) analysis for cyanotoxins. These different dilution ratios (1:1000 and 1:20) have changed the detection limit for microcystin from <0.10 micrograms per liter (µg/L) to <2.0 µg/L. The 1:20 dilution will detect toxin levels between 2 and 100 µg/L, and the 1:1000 dilution will detect toxin levels between 100 and 5,000 µg/L. These new dilution ratios should result in faster lab results. If further precision is needed, the lab will run additional dilutions.

The DWQ monitoring crew observed visible cyanobacteria in the water column that resembled grass clippings. The water was a green hue.

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.

The Warning Advisory for Box Lake and McClellan Lake remains in place.

Data Summary

Box Lake

  • Sample Type: Elbow-depth integrated composite sample
  • Sample Date: August 29, 2019
  • Microcystin: <2.0 micrograms per liter (µg/L)
  • Cyanobacteria cell counts: 4,473 cells per milliliter (cells/mL)

McClellan Lake

  • Sample Type: Elbow-depth integrated composite sample
  • Sample Date: August 29, 2019
  • Microcystin: <2.0 micrograms per liter (µg/L)
  • Cyanobacteria cell counts: 677 cells per milliliter (cells/mL)

Update September 4, 2019: Big East Lake

The Utah County Health Department (UCHD) has issued a Warning Advisory for Big East Lake in the Payson Lakes Complex after a 12-year-old girl fell ill after recreating in the lake on September 1, 2019, and September 2, 2019. The girl’s mother reported scum on and near the shore, and the girl’s symptoms are consistent with dermal exposure and ingestion of cyanobacteria.

The Division of Water Quality (DWQ) is coordinating monitoring efforts with UCHD to collect follow-up samples. DWQ will provide updates as sampling data become available.


Update August 28, 2019: Box Lake

The Division of Water Quality (DWQ) received toxin test results from the Utah Public Health Lab (UPHL) on August 27, 2019, for samples collected August 16, 2019, at Box Lake. Microcystin and anatoxin-a concentrations were well below the recreation health-based threshold for a Warning Advisory. Cyanobacteria cell-count concentrations are still pending from PhycoTech.

The advisory for Box Lake can be lifted after two consecutive weeks of sampling fall below the recreation health-based threshold. DWQ will know more once it receives cell count densities for the August 16, 2019 samples. If cell counts fall below health-based thresholds for this sample, the advisory may be lifted as toxin test results and cell counts for the August 7, 2019, samples were well below the advisory threshold. However, DWQ does not currently have the lab data to support that determination.

The DWQ monitoring crew observed filamentous algae along the shore. The water had a green hue, and the water column was murky.

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.

The Warning Advisory for Manning Meadow Reservoir remains in place pending receipt of test results for cyanobacteria cell count concentrations.

Elbow-depth integrated composite sample

  • Sample Date: August 16, 2019
  • Microcystin: <0.10 micrograms per liter (µg/L)
  • Anatoxin-a: <0.10 µg/L

Update August 28, 2019: McClellan Lake

McClellan Lake, August 16, 2019

The Division of Water Quality (DWQ) received toxin test results from the Utah Public Health Lab (UPHL) on August 27, 2019, for samples collected August 16, 2019, at McClellan Lake. Microcystin concentrations were well below the recreation health-based threshold for a Warning Advisory, but anatoxin-a was detected in the water column sample. Cyanobacteria cell-count concentrations are still pending from PhycoTech.

The DWQ monitoring crew observed filamentous algae along the shore. The water had a green hue and the water column was murky.

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.

Due to the detection of anatoxin-a, the Warning Advisory for McClellan Lake remains in place.

Data Summary

  • Sample Type: Elbow-depth integrated composite sample
  • Sample Date: August 16, 2019
  • Microcystin: <0.10 micrograms per liter (µg/L)
  • Anatoxin-a: 0.10 µg/L

Update August 5, 2019: Box Lake

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.