Panguitch Lake Algal Bloom Monitoring 2018

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24-Hour DEQ Environment Incidents Line: (801) 536-4123

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If you believe you or your pet have been exposed to a harmful algal bloom, call (800) 222-1222.

Panguitch Lake is located approximately 18 miles southwest of the city of Panguitch and sits at an elevation of 8,812 feet in the Dixie National Forest. The lake is a popular camping and water recreation destination.

Update November 8, 2018

The Division of Water Quality (DWQ) recently received test results from five samples collected at or near Panguitch Lake on October 31, 2018. The monitoring crew visited 19 sites onshore and offshore to get a better idea of the distribution of cyanobacteria at different areas of the lake.

Surface samples collected at the northeast shore and the north boat ramp had extremely high cell counts, with cell count densities of approximately 21 million cells per milliliter (cells/ml) and 11 million cells/ml, respectively. These cell-count concentrations exceeded the recreation health-based threshold for a Danger Advisory. However, cell counts in the water-column samples were all well below advisory levels.

Toxin test results from the Utah Public Health Lab (UPHL) were non-detect for anatoxin-a in the water-column samples but exceeded recreation health-based thresholds for a Warning Advisory in the surface samples at the northeast shore and north boat ramp. Microcystin test results showed a similar pattern, with toxin levels in the surface samples exceeding the recreation health-based thresholds for a Warning Advisory, and water-column samples falling well below advisory levels.

These test results indicate that while microcystin levels and cyanobacteria concentrations are very high in surface scums, toxins and cyanobacteria are not dispersed throughout the water column, and surface scums are very limited in size (50-200 square feet).

Surface samples were collected at northeast corner near the dam and the north boat ramp because these areas contained the highest concentration of bloom material. Cyanobacteria accumulations resembling green grass clippings were observed along the shore and in the open water. Every site visited showed the presence of cyanobacteria.

The monitoring crew samples two sites approximately three meters offshore to determine the distribution of cyanobacteria in the water column. Cyanobacteria resembling grass clippings were observed throughout the water three meters from shore on the west end of the lake. Overall, the bloom size was significantly smaller compared to the previous week, especially in the northern part of the lake near the outflow.

The crew collected water-column samples below Panguitch Lake at White Bridge Campground to see how much bloom material was exiting the reservoir. The stream was barely flowing and most of it was covered with ice. The crew saw no visual evidence of cyanobacteria.

Based on recent photo images and sample results, the remnants of the cyanobacteria bloom are limited to the northern shoreline area between the boat ramp and outlet of the lake rather than the entire lake. The Southwest Utah Health Department has lifted the Danger Advisory and removed all advisory signs for Panguitch Lake.

Sample Locations and Sample Types

• White Bridge Campground below Panguitch Lake (elbow-depth integrated composite sample)
• Northeast shore (surface sample)
• North boat ramp (surface sample)
• North offshore (elbow-depth integrated composite sample)
• West offshore (elbow-depth integrated composite sample)

Toxin Test Results

• Test results from the Utah Public Health Lab (UPHL)
• White Bridge Campground below Panguitch Lake: <0.10 micrograms per liter (µg/L) of anatoxin-a; 0.11 µg/L of microcystins
• Northeast shore: 0.13 µg/L of anatoxin-a; 86 µg/L of microcystins (100x dilution)
• North boat ramp: 0.26 µg/L of anatoxin-a; >50 µg/L of microcystins (10x dilution)
• North offshore: <0.10 µg/L of anatoxin-a; 0.57 µg/L of microcystins
• West offshore: <0.10 µg/L of anatoxin-a; 0.19 µg/L of microcystins

Cyanobacteria Cell-Count Concentrations

• White Bridge Campground below Panguitch Lake: 785 cells per milliliter (cells/ml)
• Northeast shore: 21,170,750 cells/ml
• North boat ramp: 10,760,591 cells/ml
• North offshore: 2,132 cells/ml
• West offshore: 1,587 cells/ml

Update October 26, 2018

The Division of Water Quality (DWQ) recently received toxin test results and cyanobacteria cell-count concentrations from samples collected at and near Panguitch Lake on October 18, 2018. Microcystin levels and cyanobacteria cell-count densities exceeded the recreation health-based threshold for a Warning Advisory.

The northeast corner near the dam contained the most abundant concentration of cyanobacteria in the lake. While cyanobacteria were concentrated along the shore, monitoring crews also observed evidence of cyanobacteria in the open water that looked like green clumps in the water. Some consolidation of cyanobacteria was also seen along the shore of the north boat ramp. Some isolated cyanobacteria resembling green grass clipping were seen in the water column along the eastern shore near the Bear Paw Resort. Overall, the bloom appeared to have decreased in size from the previous week.

The Danger Advisory/Closure remains in effect at Panguitch Lake.

Sample Locations and Sample Types

• Northeast Shore (surface sample)North Boat Ramp (surface sample)
• Whitebridge Campground/Panguitch Creek (elbow-depth integrated composite sample)

Toxin Test Results

Test results from the Utah Department of Agriculture and Food (UDAF) lab

• Panguitch Lake northeast shore: <0.10 micrograms per liter (µg/L) of anatoxin-a; 918 µg/L of microcystins (500x dilution)
• Panguitch Lake north boat ramp: <0.10 µg/L of anatoxin-a; 63 µg/L of microcystins (100x dilution)
• Whitebridge Campground: <0.10 µg/L of anatoxin-a; 0.44 µg/L of microcystins

Cyanobacteria Cell-Count Concentrations

• Northeast shore: 2,540,315 cells per milliliter (cells/ml)
• North boat ramp: 1,446,765 cells/ml
• Whitebridge Campground: 384 cells/ml

Update October 13, 2018

The Division of Water Quality (DWQ) received cyanobacteria cell-count concentration results today for samples collected on the northeast shore of Panguitch Lake on October 1, 2018. Cyanobacteria cell-count densities of 40,681,140 cells per milliliter (cells/ml) exceeded the recreation health-based threshold for a Danger Advisory.

The Danger Advisory for Panguitch Lake remains in effect.

Update October 24, 2018

The Division of Water Quality (DWQ) recently received toxin test results and cyanobacteria cell-count densities from October 8, 2018, samples from the northeast shore of Panguitch Lake. Tests conducted by the Utah Public Health Lab (UPHL) showed anatoxin-a concentrations of 0.25 micrograms per liter (µg/L), which exceeded the recreation health-based threshold for a Warning Advisory. Microcystin levels continued to be extremely high, climbing to 38,000 µg/L after 15,000x dilution, 19 times greater than the recreation health-based threshold for a Danger Advisory.

Cyanobacteria cell count concentrations of 35,425,798 cells per milliliter (cells/ml) were three times higher than the recreation health-based threshold for a Danger Advisory.

The highest concentration of cyanobacteria was observed at the northeast corner near the dam. Cyanobacteria were concentrated along the shore, but there was also evidence of cyanobacteria in the open water. Cyanobacteria were thick and looked like spilled green paint. Some consolidation of cyanobacteria was also seen along the shore of the North Boat ramp. Overall, the bloom size appeared to have decreased compared to the previous week.

The Danger Advisory/Closure for Panguitch Lake remains in effect.

Update October 12, 2018

The Division of Water Quality (DWQ) recently received lab results for samples collected on or near Panguitch Lake on September 24, 2018, and October 1, 2018.

The Utah Public Health Lab performed 10,000x dilution on samples collected on the northeast shore of Panguitch Lake on October 1, 2018. Microcystin levels were 27,000 ug/L, more than 13.5 times higher than the recreation health-based threshold for a Danger Advisory. Anatoxin-a was present at 0.33 ug/L.

Panguitch Lake continues to have high cyanobacteria cell-count concentrations. Samples collected on September 24, 2018, at the northeast shore of the lake showed cell counts just under 7 million cells per milliliter (cells/ml), which exceeds the recreation health-based threshold for a Warning Advisory. Cell counts at the White Bridge campground were elevated but below the 20,000 cells/ml threshold for a Warning Advisory.

• White Bridge Campground: 16,223 cells/ml
• Panguitch Lake northeast shore: 6,879,782 cells/ml

The Danger Advisory for Panguitch Lake remains in place.

Update October 9, 2018

The Division of Water Quality (DWQ) visited Panguitch Lake on October 1, 2018, and collected surface samples at the northern end of the lake where the crew observed an accumulation of cyanobacteria. The bloom appeared to less abundant compared with the previous week. No samples were taken downstream because the outlet flow from Panguitch Lake was not discharging. HABs danger signs were posted at three locations: the south boat ramp, the north boat ramp, and the eastern shore.

Utah Department of Agriculture and Food (UDAF) lab toxin test results showed anatoxin-a levels of 0.30 micrograms per liter (µg/L) and microcystin levels of >5,000 µg/L (5,000x dilution). Further dilutions by the lab will be necessary to quantify microcystin concentrations, and preliminary values could go even higher after these dilutions.

The Danger Advisory for Panguitch Lake remains in place.

Update October 1, 2018

The Division of Water Quality (DWQ) visited Panguitch Lake and Panguitch Creek on September 24, 2018, and collected samples on the northeast shore of the lake and the White Bridge campground.

Toxin test results from the Utah Department of Agriculture and Food (UDAF) lab were non-detect for anatoxin-a at both locations, but microcystin levels were quite high, particularly at Panguitch Lake, which showed microcystin levels of >25,000 micrograms per liter (µg/L) after 5,000x dilution. These levels are 12.5 times higher than the recreation health-based threshold for a Danger Advisory. Microcystin levels of 35.5 µg/L in Panguitch Creek after 25x dilution exceed the recreation health-based threshold for a Warning Advisory.

The UDAF lab will perform additional dilutions on the Panguitch Lake sample to quantify microcystin concentrations. Levels could go higher after further dilutions.

Evidence of cyanobacteria was observed at all four monitoring sites. The cyanobacteria accumulation was thickest along the northern shore near the outlet and looked like green paint within and on the surface of the water. DWQ collected surface samples at this location. Cyanobacteria was also observed in the water near the northern boat ramp. Monitoring crews collected elbow-depth integrated composite samples downstream from Panguitch Lake at White Bridge Campground due to accumulation at the outlet of the lake. Cyanobacteria was also observed in the water column in the stream at White Bridge Campground.

DWQ monitoring crews are collecting additional samples today, October 1, 2018.

The Danger/Closure Advisory for Panguitch Lake remains in place.

Toxin Test Results

Lab results from the Utah Department of Agriculture and Food (UDAF) lab

• Panguitch Lake northeast shore: anatoxin-a of <0.10 µg/L; microcystin of >25,000 µg/L (5000x dilution)
• Panguitch Creek (White Bridge campground): anatoxin-a of <0.10 µg/L; microcystin of 35.5 µg/L (25x dilution)

Update September 27, 2018

The Division of Water Quality (DWQ) received cyanobacteria cell-counts for a sample taken on Panguitch Lake on September 12, 2018. The lab tests found cyanobacteria cell-count densities of 2,708,853 cells per milliliter (cells/ml). While these cell-count concentrations fall within the threshold for a Warning Advisory, Panguitch Lake remains under a Danger Advisory/Closure due to extremely high toxin levels.

Update September 24, 2018

• Read the Southwestern Utah Health Department News Release

The Southwestern Utah Health Department has issued a Danger Advisory/Closure for Panguitch Lake based on extremely high toxin levels in the lake from an ongoing cyanobacteria bloom. Closure signs will be posted today.

Toxin test results from the Utah Public Health Lab (UPHL) for samples collected on September 12, 2018, show microcystin levels after 5000x dilution that were 18.5 times higher than the recreation health-based threshold for a Danger Advisory. Further dilutions by the lab will be necessary to quantify microcystin concentrations, and these levels could go even higher after these dilutions.

The Utah Department of Agriculture and Food (UDAF) contacted livestock operators in the area and recommended they prevent their cattle from drinking water from the reservoir and downstream sources. UDAF advises producers to find alternative water sources until conditions improve.

The Division of Water Quality (DWQ) and UDAF are visiting Panguitch Lake today, September 24, 2018, to collect further samples.

Update September 21, 2018

The Division of Water Quality (DWQ) visited Panguitch Lake on September 12, 2018, and observed cyanobacteria blooms at all three monitoring sites on the lake. DWQ collected samples at the northern end of the lake where the cyanobacteria accumulation was the greatest. This location is also where Panguitch Lake exits into Panguitch Creek.

Toxin test results from the Utah Public Health Lab (UPHL) for samples collected on September 12, 2018, show microcystin levels after 5000x dilution that were 18.5 times higher than the recreation health-based threshold for a Danger Advisory. Further dilutions by the lab will be necessary to quantify microcystin concentrations, and these levels could go even higher after these dilutions.

DWQ collected samples from Panguitch Creek at the White Bridge Campground below Panguitch Lake on September 18, 2018. Toxin test results were non-detect for anatoxin and >5 µg/L for microcystins. Further dilutions by the lab will be necessary to quantify microcystin concentrations, and the preliminary values could go even higher after these dilutions.

Toxin Test Results

Panguitch Lake

Test results from the Utah Public Health Lab (UPHL)

• Anatoxin-a: <0.1 micrograms per liter (µg/L)
• Microcystin: >37,000 µg/L

White Bridge Campground (below Panguitch Lake)

Test results from the Utah Department of Agriculture and Food (UDAF) lab

• Anatoxin-a: <0.1 µg/L
• Microcystin: >5 µg/L

Update August 21, 2018

Cyanobacteria cell-count concentrations from a sample collected August 8, 2018, at the Panguitch Lake Boat ramp showed high cell counts of 5,229,989 cells per milliliter (cells/ml). These cell densities exceed the recreation health-based threshold for a Warning Advisory. The reservoir remains under a Warning Advisory based on microcystin levels and cyanobacteria cell-count concentrations.

Warning Advisory for Panguitch Lake

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

Update August 15, 2018

Lab results from the Utah Public Health Lab (UPHL) for the sample collected at the Panguitch Lake North Boat Ramp on August 8, 2018, showed microcystin levels of 8.6 micrograms per liter (µg/L) and 0.19 µg/L of anatoxin-a. Toxin levels for both anatoxin-a and microcystin exceed the recreation health-based threshold for a Warning Advisory.

Update August 14, 2018

The Division of Water Quality (DWQ) observed a cyanobacteria bloom on interpolated satellite imagery and visited Panguitch Lake on August 7, 2018. The monitoring crew visited two sites on the north side of the lake and one site on the south side of the lake. The bloom appeared to be predominantly in the northeastern portion of the lake. The cyanobacteria were clumped into small masses floating on the water.

Toxin strip tests for a sample taken at the north boat ramp were non-detect for anatoxin-a and invalid for microcystin. The sample has been delivered to multiple labs for further analysis.