Scofield 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.

Update November 8, 2019

The Southeast Utah Public Health Department (SUHD) has removed the Warning Advisory on Scofield Reservoir. Toxin test results received from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) at Madsen Bay and below the dam on October 24, 2019, and the open water on October 28, 2019, showed anatoxin-a and microcystin levels well below the recreation health-based threshold for a Warning Advisory.

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.

Data Summary

Open Water

• Sample date: October 28, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Madsen Bay

• Sample date: October 24, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Below the Dam

• Sample date: October 24, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Update October 30, 2019

Toxin test results for samples collected by the Division of Water Quality (DWQ) on October 10, 2019, and October 17, 2019, at various locations at Scofield Reservoir were well below the recreation health-based threshold for a Warning Advisory. Cyanobacteria cell-count concentrations 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.

The Warning Advisory remains in place pending cyanobacteria cell counts from PhycoTech.

Data Summary

Southwest Beach

• Sample date: October 17, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Below the Dam

• Sample date: October 17, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Madsen Bay

• Sample date: October 17, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Below the Dam

• 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

Near the Dam

• 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 October 15, 2019

Toxin test results and cyanobacteria cell-count concentrations for some of the samples collected by the Division of Water Quality (DWQ) on September 27, 2019, and October 3, 2019, below and near the dam at Scofield Reservoir exceeded the recreation health-based threshold for a Warning Advisory. Satellite imagery indicates a lakewide bloom.

The DWQ monitoring crew observed cyanobacteria that resembled grass clippings in the water column. Cyanobacteria were persistent at all locations. The crew observed similar cyanobacteria concentrations at the outlet stream, which they remarked was unusual. The crew took finished water samples at the Price River Water Improvement District; these samples were non-detect for both microcystin and anatoxin-a.

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 remains in place.

Data Summary

Below the Dam

• Sample date: October 3, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 2.3 micrograms per liter (µg/L)
• Anatoxin-a: 0.136 µg/L
• Cyanobacteria cell counts: 19,791 cells per milliliter (cells/mL)

Near the Dam

• Sample date: October 3, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.101 µg/L
• Cyanobacteria cell counts: 9,883 cells per milliliter (cells/mL)

Below the Dam

• Sample date: September 27, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.10 µg/L
• Cyanobacteria cell counts: 10,471 cells per milliliter (cells/mL)

Near the Dam

• Sample date: September 27, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 3.1 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: 69,078 cells per milliliter (cells/mL)

Update September 25, 2019

Cyanobacteria cell-count concentration results from samples collected by the Division of Water Quality (DWQ) on September 18, 2019, at Madsen Bay at Scofield Reservoir exceeded the recreation health-based threshold for a Warning Advisory. Toxin test results at all sample sites were below the advisory threshold, as were cyanobacteria cell-counts from samples taken below the dam. The primary taxon in the samples was Aphanizomenon.

Scofield Reservoir remains open for recreation at this time. Recreationists are advised to not swim or waterski in areas of scum, avoid boating in areas of scum, keep animals away, and not ingest water. Visitors can still recreate in the reservoir but are cautioned to be mindful of water conditions, as blooms may move or disperse depending on temperature, wind, and weather.

The DWQ monitoring crew observed cyanobacteria in the water column that resembled bright green grass clippings. Some of the cyanobacteria were clumped together. The water had a green hue, and the cyanobacteria seemed well dispersed throughout the entire water column and out into the open water. Similar visual concentrations of cyanobacteria were observed at the outlet stream, which the crew noted is unusual.

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 remains in place for Madsen Bay.

Data Summary

Madsen Bay

• Sample date: September 18, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 2.6 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: 71,471 cells per milliliter (cells/mL)

Madsen Bay North

• Sample date: September 18, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <0.10 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: 24,737 cells per milliliter (cells/mL)

Below the Dam

• Sample date: September 18, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: 16,572 cells per milliliter (cells/mL)

Update September 17, 2019

Toxin test results received from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) below and near the dam at Scofield Reservoir on September 11, 2019, showed anatoxin-a levels exceeding the recreation health-based threshold for a Warning Advisory in both locations. Microcystin levels and cyanobacteria cell-count concentrations were well below the advisory threshold. The primary taxon in the samples was Aphanizomenon.

Scofield Reservoir remains open for recreation at this time. Recreationists are advised to not swim or waterski in areas of scum, avoid boating in areas of scum, keep animals away, and not ingest water. Visitors can still recreate in the reservoir but are cautioned to be mindful of water conditions, as blooms may move or disperse depending on temperature, wind, and weather.

The DWQ monitoring crew observed visible cyanobacteria that resembled grass clippings in the water column at the two sample sites and saw similar concentrations at all sites in the reservoir. The water column was clear aside from the cyanobacteria. Similar visual concentrations of cyanobacteria were observed at the outlet stream, which the crew noted is unusual.

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 remains in place for Madsen Bay.

Data Summary

Elbow-depth integrated composite sample: Price River Below the Dam

• Sample date: September 11, 2019
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.14 µg/L
• Cyanobacteria cell counts: 9,542 cells per milliliter (cells/mL)

Elbow-depth integrated composite sample: Near the Dam

• Sample date: September 11, 2019
• Microcystin: 2.1 micrograms per liter (µg/L)
• Anatoxin-a: 0.12 µg/L
• Cyanobacteria cell counts: 8,700 cells per milliliter (cells/mL)

Update September 13, 2019

The Southeast Utah Health Department (SUHD) posted Warning Advisory signs at Madsen Bay on Scofield Reservoir on September 13, 2019, to alert the public that the area is experiencing a harmful algal bloom. The Madsen Bay Campground is open.

Scofield Reservoir remains open for recreation at this time. Recreationists are advised to not swim or waterski in areas of scum, avoid boating in areas of scum, keep animals away, and not ingest water. Visitors can still recreate in the reservoir but are cautioned to be mindful of water conditions, as blooms may move or disperse depending on temperature, wind, and weather.

Toxin test results for samples collected by the Division of Water Quality (DWQ) at Madsen Bay on Scofield Reservoir on September 4, 2019, showed anatoxin-a levels that exceeded the recreation health-based thresholds for a Warning Advisory. Microcystin levels were well below the health advisory threshold at all sample locations, as were cyanobacteria cell-count concentrations.

The DWQ monitoring crew observed small cyanobacteria particulates that resembled grass clippings in the water column. The water had a green hue. The bloom appeared to have dissipated slightly from the previous week but was still present throughout the reservoir.

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

Madsen Bay Beach

• Sample date: September 4, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.11 µg/L
• Cyanobacteria cell counts: Unavailable

Boy Scout Camp

• Sample date: September 4, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: 6,177 cells per milliliter (cells/mL)

River below Dam

• Sample date: September 4, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: 137 cells per milliliter (cells/mL)

Update September 3, 2019

Cyanobacterial cell-count results received late on August 30, 2019, by the Division of Water Quality (DWQ) for samples collected on Scofield Reservoir on August 29, 2019, exceeded the recreation health-based threshold for a Warning Advisory. The primary cyanobacteria taxa found in the samples was Aphanizomenon. Toxin test results received from the Utah Public Health Lab (UPHL) were well below the advisory threshold.

The DWQ monitoring crew observed visible cyanobacteria in the water column that resembled grass clippings. Some of the cyanobacteria clumped together and concentrated on the surface. The water was a green hue.

A Warning Advisory indicates a moderate relative probability of acute health risk, a 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

Scofield Near the Dam

• Sample Type: Surface sample
• Sample Date: August 29, 2019
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10µg/L
• Cell Counts: 37,103 cells per milliliter (cells/mL)

Scofield Near the Dam

• Sample Type: Elbow-depth integrated composite sample
• Sample Date: August 29, 2019
• Cell Counts: 6,638 cells per milliliter (cells/mL)

Scofield Boat Ramp Madsen Bay

• Sample Type: Elbow-depth integrated composite sample
• Sample Date: August 29, 2019
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10µg/L
• Cell Counts: 35,707 cells per milliliter (cells/mL)

Update August 30, 2019

On August 29, 2019, the Division of Water Quality (DWQ) received a report of a potential harmful bloom at Scofield Reservoir. DWQ field staff visited the reservoir and provided same-day visual confirmation of a cyanobacteria bloom throughout the reservoir.

The division collected samples at multiple locations on August 29, 2019. Toxin-screening testing conducted on August 29 and 30, 2019, was nondetect for microcystin and anatoxin-a. DWQ delivered the samples to the lab for toxin analysis and cell identification and concentration. Results are expected sometime next week.

Scofield Reservoir remains open for recreation. It’s recommended that recreationists not swim or water ski in areas of scum, avoid boating in areas of scum, not ingest untreated water, and keep animals away from the water. Visitors are cautioned to be mindful of water conditions, as blooms may move or disperse depending on temperature, wind, and weather.