Utah Lake 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.

Visit the Utah Lake Water Quality Study page

Visit the 2019 Photo Gallery

Utah County Alerts

To sign up for updates go to alerts.utahcounty.gov and create an account. Select contact methods. Create a profile, select location. Choose alert subscription “Utah Lake” under “Utah County Alerts.”

Update November 12, 2019

The Utah CountyHealth Department (UCHD) has removed the Warning Advisory for Utah Lake. Toxin test results from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) on October 28, 2019, at three locations on Utah Lake were below the recreation health-based threshold for a Warning Advisory for anatoxin-a and microcystin.

The HABs monitoring season ended on October 31, 2019. The Utah Department of Health and local health departments have determined that the health risk from HABs from primary contact recreation drops with the onset of colder temperatures.

The close of the monitoring season and removal of advisories doesn’t mean HABs are no longer present. HABs can persist throughout the fall and winter and can pose a potential threat to humans and pets. It’s important 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

Vineyard Buoy

• 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

Lincoln Marina

• Sample date: October 28, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: 2.8 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Middle of Provo Bay

• 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

Update October 30, 2019

Toxin test results from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) on October 15, 2019, and October 21, 2019, at Utah Lake showed that the samples collected on October 15 at the Vineyard Buoy and the samples collected on October 21, 2019, in the middle of Provo Bay exceeded the recreation health-based threshold for a Warning Advisory for anatoxin-a. Anatoxin-a and microcystin levels for all other samples collected on October 15, 2019, and October 21, 2019, were below the advisory threshold. Cyanobacteria cell-count concentrations are pending from PhycoTech, with the exception of samples collected on October 15, 2019, from Lincoln Marina that exceeded the recreation health-based threshold for a Warning Advisory

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 Utah Lake remains in place.

Data Summary

Two miles west of Vineyard

• Sample date: October 21, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Lincoln Marina

• Sample date: October 21, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: 2.5 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

One mile southeast of Bird Island

• Sample date: October 21, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Middle of Provo Bay

• Sample date: October 21, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: 0.16micrograms per liter (µg/L)
• Anatoxin-a: 0.13 µg/L

Two miles west of Vineyard

• Sample date: October 15, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.12 µg/L

Middle of Provo Bay

• Sample date: October 15, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

One mile east of Bird Island

• Sample date: October 15, 2019
• Sample Type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Lincoln Marina

• Sample date: October 15, 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: 51,560 cells per milliliter (cells/mL)

Update October 15, 2019

Toxin test results from the Utah Public Health Lab (UPHL) for samples collected on October 1, 2019, and October 8, 2019, by the Division of Water Quality (DWQ) at a number of locations in Utah Lake continued to show anatoxin-a and microcystin levels exceeding the recreation health-based threshold for a Warning Advisory at several locations. Cyanobacteria cell counts are pending from PhycoTech.

The DWQ monitoring crew observed cyanobacteria that resembled grass clippings and isolated clumps of cyanobacteria in the water column at Lincoln Marina. Some of the clumps had formed into mats on the surface and there were visible “clouds” of cyanobacteria clumps in the water. The water was a green hue. At the open water sites, Lindon Marina, and American Fork Marina, there were isolated clumps of cyanobacteria in the water column, and in some places the cyanobacteria were clumped together on the surface. The particles were well dispersed in 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.

The lake-wide advisory for Utah Lake remains in effect.

Data Summary

Lindon Marina

• Sample date: October 8, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cyanobacteria cell counts: Pending

Outflows at Geneva Steel

• Sample date: October 8, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 2.1 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: Pending

Provo Buoy

• Sample date: October 8, 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: Pending

Middle of Provo Bay

• Sample date: October 8, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 2.4 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: Pending

1 Mi. Southeast of Bird Island

• Sample date: October 8, 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: Pending

Lincoln Marina

• Sample date: October 8, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 6.7 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: Pending

Goshen Bay

• Sample date: October 8, 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: Pending

Vineyard Buoy

• Sample date: October 1, 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: Pending

Provo Buoy

• Sample date: October 1, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.128 µg/L
• Cyanobacteria cell counts: Pending

Provo Bay

• Sample date: October 1, 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: Pending

1 Mile SE of Bird Island

• Sample date: October 1, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: <0.10µg/L
• Cyanobacteria cell counts: Pending

Lincoln Marina

• Sample date: October 1, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 5.1 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cyanobacteria cell counts: Pending

Update October 3, 2019

Toxin test results from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) at several locations in Utah Lake continued to show anatoxin-a and microcystin levels exceeding the recreation health-based threshold for a Warning Advisory at different sites based on samples taken on September 20, 2019 and September 23, 2019.

The DWQ monitoring crew observed cyanobacteria in the form of isolated clumps, grass clippings, and a green hue in the water column at American Fork Marina, the open water of Provo Bay, 1 mile SE of Bird Island, Lincoln Beach and Lincoln Marina, the open water of Goshen Bay, Lindon Beach, and 2 miles west of Vineyard.

The lake-wide advisory for Utah Lake remains in effect.

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

Lincoln Marina

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 10.4 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

Lincoln Marina

• Sample date: September 23, 2019
• Sample type: Surface
• Microcystin: 747 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

Lincoln Point

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 0.37 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

Open Water Near Goshen

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 0.11 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

1 Mi. SE of Bird Island

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 0.36 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

American Fork Marina

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 0.37 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

Lindon Marina

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 0.23 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

Vineyard Marina

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 0.34 micrograms per liter (µg/L)
• Anatoxin-a: <0.1 µg/L
• Cell counts: Pending

Middle of Provo Bay

• Sample date: September 23, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.172 µg/L
• Cell counts: Pending

Open Water Near Goshen

• Sample date: September 20, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.172 µg/L
• Cell counts: Pending

1 Mile SE of Bird Island

• Sample date: September 20, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.125 µg/L
• Cell counts: Pending

Middle of Provo Bay

• Sample date: September 20, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.160 µg/L
• Cell counts: Pending

American Fork Marina

• Sample date: September 20, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.174 µg/L
• Cell counts: Pending

Update September 16, 2019

Toxin test results from the Utah Public Health Lab (UPHL) for samples collected by the Division of Water Quality (DWQ) at six locations in Utah Lake showed anatoxin-a levels exceeding the recreation health-based threshold for a Warning Advisory at all locations. Microcystin levels, on the other hand, were below the advisory threshold at all locations.

The DWQ monitoring crew observed cyanobacteria in the water column in Provo Bay. These cyanobacteria resembled small grass clippings. Streaks along the surface were also present at Provo Bay. The crew did not observe visible particles of cyanobacteria at some sample locations, but this could have been due to the high turbidity of the water column from recent storms. The water had 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 lake-wide advisory for Utah Lake remains in effect.

Data Summary

Goshen Bay

• Sample date: September 9, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.17 µg/L

One Mile Southeast of Bird Island

• Sample date: September 9, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 2.8 micrograms per liter (µg/L)
• Anatoxin-a: 0.21 µg/L

Provo Bay

• Sample date: September 9, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.2 µg/L

One Mile West of Provo Buoy

• Sample date: September 9, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.15 µg/L

Two Miles West of Vineyard

• Sample date: September 9, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: <2.0 micrograms per liter (µg/L)
• Anatoxin-a: 0.11 µg/L

American Fork Marina

• Sample date: September 9, 2019
• Sample type: Elbow-depth integrated composite sample
• Microcystin: 2.1 micrograms per liter (µg/L)
• Anatoxin-a: 0.2 µg/L

Update September 9, 2019

The Utah County Health Department (UCHD) has issued a lakewide Warning Advisory for Utah Lake after cyanobacterial cell counts in three open-water sampling locations exceeded the recreation health-based threshold for a Warning Advisory. UCHD is placing advisory signs at the seven permanent sign locations at the lake.

Due to the variable nature of cyanobacterial blooms on the lake during this time of the year, the lakewide Warning Advisory will remain in place throughout the month of September, at which time UCHD will reevaluate the situation.

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.

Update September 6, 2019

Cyanobacterial cell-count test results received by the Division of Water Quality (DWQ) for samples collected near Bird Island, the Vineyard Buoy, and American Fork Beach on September 3, 2019, all exceeded the recreation health-based threshold for a Warning Advisory. The primary taxon in the samples was Aphanizomenon.

Toxin test results were well below the threshold for a Warning Advisory.

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.

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.

Data Summary

One Mile Southeast of Bird Island

Sample date: September 3, 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: 72,768 cells per milliliter (cells/mL)

Vineyard Buoy

Sample date: September 3, 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: 152,155 cells per milliliter (cells/mL)

American Fork Beach

Sample date: September 3, 2019
Sample type: Elbow-depth integrated composite sample
Microcystin: 2.1 micrograms per liter (µg/L)
Anatoxin-a: <0.10 µg/L
Cyanobacteria cell counts: 120,043 cells per milliliter (cells/mL)

Update September 5, 2019

Cyanobacteria cell-count results received by the Division of Water Quality (DWQ) on September 4, 2019, for samples collected at four locations on Utah Lake on August 26, 2019, showed only Provo Bay exceeded the recreation health-based threshold for a Warning Advisory. Toxin test results for anatoxin-a and microcystin were non-detect at all locations with the exception of Provo Bay.

Cyanobacteria cell counts and toxin test results from Goshen Bay, North of Lincoln Beach, and the Lincoln Beach Marina were all well below the recreation health-based threshold for a Warning Advisory. Cell counts for Provo Bay were approximately 73,000 cells per milliliter (cells/mL), which exceeds the Warning Advisory threshold.

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 resembling grass clippings in the water column. The water was well mixed due to high winds, and the lake had a green hue. There were no visible particulates in Lincoln Marina and North of Lincoln Marina. The bloom in Provo Bay consisted of cyanobacteria resembling grass clippings and was visible below the surface of the water. The bloom formed streaks in 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.

The Warning Advisory for Lincoln Beach, Goshen Bay, and Provo Bay remains in place.

Data Summary

Goshen Bay

• Sample date: August 26, 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: 3,166 cells per milliliter (cells/mL)

Provo Bay

• Sample date: August 26, 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: 73,446 cells per milliliter (cells/mL)

North of Lincoln Beach

• Sample date: August 26, 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: 1,268 cells per milliliter (cells/mL)

Lincoln Beach Marina

• Sample date: August 26, 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: 1,217 cells per milliliter (cells/mL)

Update August 28, 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 19, 2019, at several locations on Utah Lake. Toxin test results were detect for anatoxin-a at Provo Bay and north of the Lincoln Beach Marina. Microcystin levels at all sample locations were well below the recreation health-based threshold for a Warning Advisory. Cyanobacteria cell-count concentrations are still pending from PhycoTech.

The DWQ monitoring crew observed a green hue in the water column and visible cyanobacteria blooms that resembled grass clippings at Lincoln Beach Marina, Provo Bay, and Goshen Bay during sampling on August 19, 2019, and August 26, 2019. DEQ will provide updates on the toxin test results and cyanobacteria cell counts from these samples as they become available.

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 Lincoln Beach, Goshen Bay, and Provo Bay remains in place.

Data Summary

North of the Lincoln Beach Marina (Elbow-depth Integrated Composite Sample)

• Sample Date: August 19, 2019
• Microcystin: 0.16 micrograms per liter (µg/L)
• Anatoxin-a: 0.12 µg/L

Lincoln Beach Marina (Elbow-depth Integrated Composite Sample)

• Sample Date: August 19, 2019
• Microcystin: 0.10 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Middle of Provo Bay (Elbow-depth integrated composite sample)

• Sample Date: August 19, 2019
• Microcystin: <0.10 micrograms per liter (µg/L)
• Anatoxin-a: 0.1 µg/L

Goshen Bay (Elbow-depth integrated composite sample)

• Sample Date: August 19, 2019
• Microcystin: <0.10 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Update August 15, 2019

The Utah County Health Department (UCHD) downgraded Lincoln Beach from a Danger Advisory to a Warning Advisory on August 15, 2019, after two consecutive weeks of lab results showed that cyanobacteria cell-count concentrations had dropped below the recreation health-based threshold for a Danger Advisory. The Warning Advisory for Lincoln Beach can be lifted if cell counts and toxin test results from the next samples remain below advisory thresholds.

Cyanobacteria cell counts in the samples collected on August 8, 2019, in Provo Bay exceeded the recreation health-based threshold for a Warning Advisory, and anatoxin-a levels collected on August 8, 2019, in Goshen Bay also exceeded the recreation health-based threshold for a Warning Advisory. Overall, however, toxin levels and cyanobacteria cell counts are decreasing in both locations.

The DWQ monitoring crew observed visible cyanobacteria in the water column in Lincoln Marina and North of Lincoln Marina Beach, Visible concentrations of cyanobacteria were much lower than the previous visit and were only seen in Lincoln Marina and North of Lincoln Beach. The water column was clear of cyanobacteria in Goshen Bay. The water column in Provo Bay had a green/brown hue with small, visible cyanobacteria resembling grass clippings in 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.

The Danger Advisory at Lincoln Beach Marina has been downgraded to a Warning Advisory. Provo Bay and Goshen Bay remain under a Warning Advisory.

Data Summary

North of the Lincoln Beach Marina (Surface Sample)

• Sample Date: July 29, 2019
• Microcystin: 460 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 2,679,877 cells per milliliter (cells/mL)

North of the Lincoln Beach Marina (Elbow-Depth Integrated Composite Sample)

• Sample Date: August 5, 2019
• Microcystin: 0.178 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 15,794 cells per milliliter (cells/mL)

Lincoln Beach Marina (Surface Sample)

• Sample Date: July 29, 2019
• Microcystin: 750 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 5,058,407 cells per milliliter (cells/mL)

Lincoln Beach Marina (Elbow-Depth Integrated Composite Sample)

• Sample Date: July 29, 2019
• Microcystin: 0.36 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 14,918 cells per milliliter (cells/mL)

Lincoln Beach Marina (Elbow-Depth Integrated Composite Sample)

• Sample Date: August 5, 2019
• Microcystin: 0.224 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 8,476 cells per milliliter (cells/mL)

Lindon Marina (Elbow-depth integrated composite sample)

• Sample Date: August 5, 2019
• Microcystin:<0.10 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 0 cells per milliliter (cells/mL)

Swede Access (Elbow-depth integrated composite sample)

• Sample Date: August 5, 2019
• Microcystin: 0.13 micrograms per liter (µg/L)
• Anatoxin-a: 0.115 µg/L
• Cell Counts: 23,737 cells per milliliter (cells/mL)

Middle of Provo Bay (Elbow-depth integrated composite sample)

• Sample Date: August 8, 2019
• Microcystin: 0.137 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L

Goshen Bay (Elbow-depth integrated composite sample)

• Sample Date: August 8, 2019
• Microcystin: 0.116 micrograms per liter (µg/L)
• Anatoxin-a: 0.12 µg/L
• —

Update August 5, 2019

Toxin-test results and cyanobacteria cell-counts from samples collected by the Division of Water Quality (DWQ) on July 29, 2019, show decreases in toxin levels and cell counts. The Lincoln Beach Marina, however, continues to register high levels of both toxins and cyanobacterial cell-count densities. Aphanizomenon, Dolichospermum, and Microcystis were the three main cyanobacteria taxa found in the samples.

The DWQ monitoring crew observed three types of cyanobacteria present in the Lincoln Beach area. The crew observed cottage-cheese type cyanobacteria with high concentrations of isolated clumps along the shore north of the Lincoln Beach Marina. The marina itself contained isolated clumps of cyanobacteria that resembled grass clippings. High winds at Goshen Bay appear to have dispersed the cyanobacteria in the bay, and the crew noted that the water column was visibly clear. The water column at Provo Bay was a green/brown color and contained small, visible cyanobacteria particulates.

Two consecutive weeks of sampling are required before a health advisory can be lifted or downgraded.

A Danger Advisory indicates a high relative probability of acute health risk, cell-count density of >10 million cells per milliliter (cells/mL), microcystin levels >2,000 micrograms per liter (µg/L), or anatoxin-a levels >90 µg/L. 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 Danger Advisory remains in place for Lincoln Beach Marina. The Warning Advisory remains in place for Goshen Bay and Provo Bay.

North of the Lincoln Beach Marina

• Sample Type: Surface sample
• Sample Date: July 29, 2019
• Microcystin: 460 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 2,679,877 cells per milliliter (cells/mL)

Lincoln Beach Marina (Surface Sample)

• Sample Date: July 29, 2019
• Microcystin: 750 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 5,058,407 cells per milliliter (cells/mL)

Lincoln Beach Marina (Elbow-Depth Integrated Composite Sample)

• Sample Date: July 29, 2019
• Microcystin: 0.36 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 14,918 cells per milliliter (cells/mL)

Middle of Provo Bay

• Sample Type: Elbow-depth integrated composite sample
• Sample Date: July 29, 2019
• Microcystin: 0.13 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 22,754 cells per milliliter (cells/mL)

Goshen Bay

• Sample Type: Elbow-depth integrated composite sample
• Sample Date: July 29, 2019
• Microcystin: 0.14 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 286 cells per milliliter (cells/mL)

Update August 1, 2019

The Utah County Health Department (UCHD) has lifted the lake-wide Warning Advisory for Utah Lake after cyanobacteria cell-count concentrations from samples collected on July 22, 2019, in the open water near Pelican Point were well below the recreation health-based threshold values for a Warning Advisory. Toxin-test results were also well below advisory thresholds.

Cyanobacteria cell-counts from samples collected in Provo Bay on July 22, 2019, showed values of 35,706 cells/mL, which are above the threshold values for a Warning Advisory. Toxin results were well below Utah recreational health advisory thresholds. Cell counts from samples collected in Goshen Bay on July 22, 2019, showed values of 53,803 cells/mL, which are above the threshold values for a Warning Advisory. Toxin-test results showed levels well below Utah recreational health advisory thresholds.

The Division of Water Quality (DWQ) conducted open-water response sampling on July 22, 2019, and visited 13 locations across the lake. A number of the sites had a green hue but no visible cyanobacteria or particulates in the water column. The crew observed several types of cyanobacteria in the southwest area of the lake. The beach north of Lincoln Marina contained cyanobacteria with the consistency of “cottage cheese” with high concentrations of isolated clumps along the shore. Isolated clumps of cyanobacteria resembling grass clippings were observed inside Lincoln Marina. The water column in the open water near Goshen Bay also contained concentrated cyanobacteria resembling grass clippings.

The Danger Advisory remains in place for Lincoln Marina. Warning Advisories have been issued for Provo Bay and Goshen Bay, and UCHD will post signs in those locations today.

A Danger Advisory indicates a high relative probability of acute health risk, cell-count density of >10 million cells per milliliter (cells/mL), microcystin levels >2,000 micrograms per liter (µg/L), or anatoxin-a levels >90 µg/L. 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.

Middle of Provo Bay

• Sample Type: elbow-depth integrated composite sample
• Sample Date: July 22, 2019
• Microcystin: 0.19 micrograms per liter (µg/L)
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 35,706 cells per milliliter (cells/mL)

North of Lincoln Marina

• Sample Type: surface sample
• Sample Date: July 22, 2019
• Microcystin: >2000 µg/L
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 9,192,281 cells/mL

Lincoln Marina

• Sample Type: elbow-depth integrated composite sample
• Sample Date: July 22, 2019
• Microcystin: 59 µg/L
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 146,076 cells/mL

Goshen Bay

• Sample Type: elbow-depth integrated composite sample
• Sample Date: July 22, 2019
• Microcystin: 0.25 µg/L
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 53,803 cells/ml

South of Pelican Point

• Sample Type: elbow-depth integrated composite sample
• Sample Date: July 22, 2019
• Microcystin: 0.32 µg/L
• Anatoxin-a: <0.10 µg/L
• Cell Counts: 2,229 cells/mL

Update July 25, 2019: Lincoln Beach

The Utah County Health Department has put Lincoln Beach at Utah Lake on a Danger Advisory which includes a beach closure. Signs will be placed in Lincoln Beach Marina.

A Danger Advisory indicates a high relative probability of acute health risk, cell-count density of >10 million cells per milliliter (cells/mL), microcystin levels >2,000 micrograms per liter (µg/L), or anatoxin-a levels >90 µg/L.

Update July 24, 2019: Lincoln Beach

On July 22, 2019, the Division of Water Quality (DWQ) HABs monitoring crew was on Utah Lake for follow-up response monitoring and routine monitoring.

The crew observed isolated clumps of bright green cyanobacteria with a cottage cheese consistency on the water surface in and around the Lincoln Beach marina. Three dead fish were observed in the water. DWQ collected surface and elbow-depth integrated composite samples at the marina.

On July 24, 2019, toxin results from Utah Public Health Laboratory (UPHL) showed microcystin toxin levels in the surface sample were above the threshold for a Danger Advisory. Cyanobacteria cell-count results received on July 24, 2019, showed cell volume was also nearing the threshold for a Danger Advisory.

Microcystin is a potent liver toxin and possible human carcinogen. Cyanotoxins can also kill livestock and pets that drink affected waters. Fish and bird mortalities have also been reported in waterbodies with persistent cyanobacteria blooms.

Toxin Test Results

• Surface sample
  • >2,000 micrograms per liters (µg/L) of microcystin
  • <0.10 µg/L anatoxin-a
• Elbow-depth integrated composite sample
  • 34 µg/L microcystin
  • <0.10 µg/L anatoxin-a

Cyanobacteria Cell-Count Concentrations

• Surface sample: 9,192,281 cells per milliliter (cells/mL)
• Integrated sample: 146,076 cells/mL

Update July 23, 2019

The Division of Water Quality (DWQ) returned to Utah Lake on July 15, 2019 and collected elbow-depth integrated composite samples in the open water of Utah Lake. Results showed a decrease in the toxin microcystin and cell counts with levels of both below advisory thresholds. Utah Lake requires one more sample below thresholds before the Warning Advisory can be lifted.

• Toxin test results: 0.111 micrograms per liter (µg/L) of anatoxin-a: >0.10 µg/L of microcystin.
• Cyanobacteria cell-count concentrations: surface sample:14,316 cells/mL

Update July 12, 2019

On Wednesday, July 10, 2019, The Division of Water Quality (DWQ) collected water samples in the open water of Utah Lake. The monitoring crew observed large blooms extending at least from Pelican Point down to the entrance of Provo Bay with cyanobacteria visible in the water column and large clumps on the surface.

DWQ received cyanobacterial cell-count concentration results from PhycoTech on July 12, 2019, of 449,874 cells per milliliter (cells/mL) on the surface and 27,455 cells/mL within the water column. These cell-count densities exceed the recreation health-based threshold for a Warning Advisory. Based on these data, the Utah County Health Department has issued a Warning Advisory for Utah Lake.

The Utah County Health Department will be posting warning signs around the lake at Lincoln Beach, Sandy Beach, Pelican Point, Lindon Harbor, American Fork Harbor, Saratoga Springs City Marina, and Saratoga Springs HOA Marina.

Water samples were also delivered to the Utah Public Health Lab (UPHL) for further analysis. UPHL testing showed anatoxin-a levels of <0.10 micrograms per liter (µg/L), and microcystin levels at 1.07 ug/L on the surface and 0.185 ug/L for the depth integrated sample. Both are below the recreation health-based threshold for a Warning Advisory. While toxins were not detected at the time of sampling, the large majority of the cells found are of the genus Aphanizomenon, which has the ability to produce 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.

Update July 9, 2019

The Utah County Health Department (UCHD) has lifted the Warning Advisory for Provo Bay following two consecutive weeks of samples below advisory levels.

Samples collected by the Division of Water Quality (DWQ) on June 27, 2019, and July 3, 2019, were below cyanobacteria cell-count and toxin recreation health-based thresholds.

June 27, 2019

• Sample from open water, middle of Provo Bay; elbow-depth integrated composite sample
• Toxin test results:<0.10 micrograms per liter (μg/L) of anatoxin-a: 0.122 μg/L of microcystin
• Cyanobacteria cell-count concentrations: 3.949 cells per milliliter (cells/mL), down from 370,112 cells/mL in the June 18, 2019, sample

July 3, 2019

• Sample from open water, middle of Provo Bay, elbow-depth integrated composite sample
• Toxin test results:<0.10 μg/L of anatoxin-a: 0.26 μg/L of microcystin
• Cyanobacteria cell-count concentrations: 4,445 cells/mL

Update June 24, 2019

The Utah County Health Department (UCHD) issued a Warning Advisory on June 24, 2019, for Provo Bay after samples collected on June 18, 2019, showed high cyanobacteria cell-count concentrations. UCHD will be posting advisory signs at Sandy Beach and the Utah Lake State Park Marina.

The Division of Water Quality (DWQ) visited Utah Lake on June 17, 2019, and June 18, 2019, to collect samples and assess lake conditions. The monitoring crew did not observe visible cyanobacteria or particulates in the water column at numerous Utah Lake sample sites with the exception of Provo Bay. DWQ collected surface and depth-integrated composite samples in the open water in the middle of Provo Bay after observing a bright green hue and small green particulates in the water column.

DWQ received cyanobacteria cell-count concentrations from PhycoTech on June 24, 2019, of 370,112 cells per milliliter (cells/mL) in the surface sample. These cell-count densities exceed the recreation health-based threshold for a Warning Advisory. Most of the cyanobacteria found in the sample were identified as Dolichospermum, a taxon known to produce both anatoxin-a and microcystin.

Toxin test results were <0.10 micrograms per liter (µg/L) for anatoxin-a and 0.42 µg/L for microcystin, both of which are well below the recreation health-based threshold for an advisory.

DWQ will collect samples in Provo Bay this week to chart the progress of the bloom and monitor for changes in cell-count densities and toxin levels.

Update June 17, 2019

The Utah County Health Department (UCHD) lifted the Warning Advisory at the Saratoga Springs City Marina after samples collected by the Division of Water Quality (DWQ) on June 5, 2019, and June 13, 2019, showed microcystin levels of 0.12 micrograms per liter (µg/L). These values are well below the recreation health-based threshold for a Warning Advisory.

Per the Utah Department of Environmental Quality/Utah Department of Health guidelines, an advisory can be lifted after two weeks of data indicate that the hazard has passed.

Update June 11, 2019

The Division of Water Quality (DWQ) received cyanobacteria cell-count concentrations and taxa identification for samples collected on May 30, 2019, and June 5, 2019.

Cell-count concentrations were well below the recreation health-based threshold for an advisory with the exception of the May 30, 2019, surface sample from the Saratoga Springs Public Marina Picnic Area. Cell-count densities for this sample were 1.19 million cells per milliliter (cells/ml), which exceeds the recreation health-based threshold for a Warning Advisory. The predominant cyanobacteria taxon was microcystis, but dolichospermum, another potent toxin-producer, was also found in the sample. Elevated cell-count concentrations match the high microcystin levels found at the same location.

Toxin levels and cell-count densities have dropped significantly since the May 30, 2019, sample, indicating the bloom is dissipating. However, the Warning Advisory for the Saratoga Springs Public Marina Picnic Area will remain in effect until cell-count concentrations and toxin test results from samples collected over two consecutive weeks fall below the recreation health-based advisory level.

Sample Location and Sample Type

June 5, 2019

• Lindon Marina (elbow-depth integrated composite sample)
• Saratoga Springs City Marina (elbow-depth integrated composite sample)

Cyanobacteria Cell-Count Concentrations

• Lindon Marina: 229 cells per milliliter (cells/ml)
• Saratoga Springs City Marina: 123 cells/ml

Sample Location and Sample Type

May 30, 2019

• Saratoga Springs City Marina (surface sample)
• Saratoga Springs City Marina (elbow-depth integrated composite sample)
• Lindon Marina (elbow-depth integrated composite sample)

Cyanobacteria Cell-Count Concentrations

• Saratoga Springs City Marina (surface sample): 1,194,701 cells/ml
• Saratoga Springs City Marina (elbow-depth integrated composite sample): 2973 cells/ml
• Lindon Marina: none detected

Update June 10, 2019

The Division of Water Quality (DWQ) collected samples at the Saratoga Springs Public Marina Picnic Area and Lindon Marina on June 5, 2019. Toxin test results for microcystins were well below advisory levels for both samples.

The updated toxin result for the depth-integrated sample collected on May 30, 2019, at the Saratoga Springs site was 14 micrograms per liter (µg/L) for microcystin. This toxin level was over three times greater than the health-based recreation threshold.

The Warning Advisory for the Saratoga Springs Public Marina Picnic Area will remain in effect until toxin test results from samples collected over two consecutive weeks fall below the health-based recreation advisory level.

Sample Location and Sample Type

• Saratoga Springs City Marina (elbow-depth integrated composite sample)
• Lindon Marina (elbow-depth integrated composite sample)

Toxin Test Results

• Saratoga Springs City Marina: 0.12 micrograms per liter (µg/L) of microcystin
• Lindon Marina: <0.10 µg/L of microcystin

Update June 5, 2019

The Division of Water Quality (DWQ) visited Utah Lake for routine monitoring on May 30, 2019, and collected three samples total at two locations that appeared to be experiencing cyanobacterial blooms. DWQ delivered these samples to the Utah Public Health Lab (UPHL) for further testing after toxin-test strip results came back invalid.

Both samples for the Saratoga Springs Public Marina Picnic Area significantly exceeded the recreation health-based threshold for a Warning Advisory for microcystin, with the surface sample registering microcystin levels 375 times greater than the advisory level.

Water-quality scientists observed that the Lindon Marina Beach was a green hue with small particulates. The potential bloom/green color was concentrated in the northeast beach area outside the marina. The Saratoga Springs Public Marina Picnic Area had isolated green clumps concentrated along the shore of the beach, and particulates were visible throughout the water column. All other sites were clear with no visible particulates.

DWQ monitoring crews returned to Utah Lake on June 5, 2019, to collect additional samples in the affected area. Samples will be sent to UPHL for toxin testing and Phycotech for cell-count concentrations and species identification.

The Utah County Health Department (UCHD) has issued a Warning Advisory for the Saratoga Springs Public Marina Picnic Area and posted signs at the picnic area. The remainder of the lake is NOT under an advisory.

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. Advisory actions:

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

Sample Location and Sample Type

• Lindon Marina (elbow-depth integrated composite sample)
• Saratoga Springs City Marina (surface sample)
• Saratoga Springs City Marina (elbow-depth integrated composite sample)

Toxin Test Results

• Lindon Marina Beach: <0.10 micrograms per liter (µg/L) of anatoxin-a; 0.13 µg/L of microcystin
• Saratoga Springs City Marina (surface sample): <0.10 µg/L of anatoxin-a; 1500 µg/L of microcystin (1200x dilution)
• Saratoga Springs City Marina (depth-integrated sample): <0.10 µg/L of anatoxin-a; between 5 and 250 µg/L of microcystin (actual microcystin levels to be determined after additional dilutions)