Scofield Reservoir Algal Bloom Monitoring 2018

  Scofield State Park

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 13, 2018

The Southeast Health Department has lifted the Warning Advisory for Scofield Reservoir as toxin levels continue to fall and bloom activity appears limited to small areas of surface scums. Health department officials have removed warning signs.

Update November 8, 2018

The Division of Water Quality (DWQ) recently received cyanobacteria cell-count concentrations for samples collected at five sites on or near Scofield Reservoir on October 30, 2018. Test results for surface sample near the dam showed cell-counts of approximately 34.5 million cells per milliliter (cells/ml), which exceeded the recreation health-based threshold for a Danger Advisory. However, water-column samples from the same location were below advisory thresholds. Surface sample results of approximate 1.7 million cells/ml at the southeast angler access exceeded the recreation health-based threshold for a Warning Advisory, while water-column samples showed significantly lower cell counts.

These results indicate that while cyanobacteria concentrations are extremely high in surface scums, they are not dispersed throughout the water column.

Toxin test results from the Utah Public Health Lab (UPHL) were all well below advisory levels for anatoxin-a and microcystins.

DWQ monitoring staff saw evidence of past blooms seen during previous weeks along the shore at the southeast angler access. Some green cyanobacteria was still present on the surface of the water along the shore, but the conditions were slightly improved from last visit. At the near dam site, there were cyanobacteria resembling “grass clippings” visible along the shore and throughout the water column. Two sets of samples were taken to show accumulation along the shore and distribution throughout the water column. The bloom near the dam appear to have diminished since the previous week, but cyanobacteria were still observed floating throughout the water column. In the Price River below Scofield Res, the stream was heavily drawn-down since last visit. No presence of cyanobacteria were observed.

Overall, the water was clear, with some isolated particulates. Some floating particles were seen distributed throughout the water column at Mountain View State Park, and the conditions were similar to the last visit. No current bloom was observed at the Madsen Bay boat ramp.

Conditions overall were improved from the previous week, and the cyanobacteria that were present were in isolated chunks distributed throughout the water column.

The Warning Advisory for Scofield Reservoir remains in effect.

Sample Location and Sample Type

• Scofield Reservoir outlet stream (elbow-depth integrated composite sample)
• Southeast angler access (surface sample)
• Near dam (surface sample)
• Near dam (elbow-depth integrated composite sample)
• Mountain View State Park (elbow-depth integrated composite sample)

Toxin Test Results

• Test results from the Utah Public Health Lab (UPHL)
• Scofield Reservoir outlet stream: <0.10 micrograms per liter (µg/L) of anatoxin-a; 0.30 µg/L of microcystins
• Southeast angler access: <0.10 µg/L of anatoxin-a; 0.41 µg/L of microcystins
• Near dam (surface sample): <0.10 µg/L of anatoxin-a; 0.65 µg/L of microcystins
• Near dam (water-column sample): <0.10 µg/L of anatoxin-a; 0.33 µg/L of microcystins
• Mountain View State Park: <0.10 µg/L of anatoxin-a; 0.27 µg/L of microcystins

Cyanobacteria Cell-Count Concentrations

• Scofield Reservoir outlet stream: 1,357 cells per milliliter (cells/ml)
• Southeast angler access: 1,710,565 cells/ml
• Near dam (surface sample): 34,495,811 cells/ml
• Near dam (water-column sample): 3,057 cells/ml
• Mountain View State Park: 293 cells/ml

Update November 1, 2018

The Division of Water Quality (DWQ) collected samples at four sites at or near Scofield Reservoir on October 25, 2018. Toxin test results showed anatoxin-a levels exceeding the recreation health-based threshold for a Warning Advisory at the southeast angler access and near the dam. Toxin levels for anatoxin-a and microcystins were well below recreation health-based thresholds at all other sites.

Cyanobacteria cell-counts were high at the southeast angler access, with concentrations approaching one million cells per milliliter (cells/ml). These cell-count densities exceed the recreation health-based threshold for a Warning Advisory. Cell counts were very high near the dam at approximately 65 million cells/ml. These cell-count concentrations exceed the recreation health-based threshold for a Danger Advisory. Note: these high cell counts were present in a surface sample near the dam but not in the sample of the water column at the same location. This indicates that cyanobacteria are currently concentrated in the surface area of the bloom. All other locations had low cyanobacteria cell-count densities.

The field crew reported that turbid water made it difficult to identify all visible cyanobacteria. There were cyanobacteria present along the southwest shore from past blooms and evidence of the large bloom seen last week along the shore at the southeast angler access. Some green cyanobacteria were seen distributed throughout the water column, but the conditions were much improved from the last visit. Cyanobacteria resembling grass clippings were visible along the shore at the near dam site and throughout the water column. The crew took two sets of samples to show accumulation along the shore and distribution throughout the water column. The Price River below Scofield Reservoir was heavily drawn down since the last sampling visit. Some past bloom material was present along the shore. Overall, the water was clear, with some isolated particulates. Floating particles were observed throughout the water column at Mountain View State Park similar to the last visit. There was a great deal of blue and green cyanobacteria bloom material present along the shore at the Madsen Bay Boat Ramp, but no current bloom was observed. Conditions were improved from the previous week, and the cyanobacteria present were observed in isolated chunks distributed throughout the water column.

The Warning Advisory for Scofield Reservoir remains in effect.

Sample Location and Sample Type

• Outlet stream to Price River (elbow-depth integrated composite sample)
• Southeast angler access (surface sample)
• Near dam (surface sample)
• Near dam (elbow-depth integrated composite sample)
• Mountain View State Park (elbow-depth integrated composite sample)

Toxin Test Results

Test results from the Utah Public Health Lab (UPHL)

• Outlet stream to Price River: <0.10 micrograms per liter (µg/L) of anatoxin-a; 0.37 µg/L of microcystins
• Southeast angler access: 0.25 µg/L of anatoxin-a; 0.96 µg/L of microcystins
• Near dam: 0.11 µg/L of anatoxin-a; 0.70 µg/L of microcystins
• Near dam: <0.10 µg/L of anatoxin-a; 0.38 µg/L of microcystins
• Mountain View State Park: <0.10 µg/L of anatoxin-a; 0.36 µg/L of microcystins

Cyanobacteria Cell-Count Concentrations

• Outlet stream to Price River: 1,927 cells per milliliter (cells/ml)
• Southeast angler access: 907,922 cells/ml
• Near dam (surface sample): 64,874,697 cells/ml
• Near dam (integrated sample): 4,562 cells/ml
• Mountain View State Park: 558 cells/ml

Update October 29, 2018

The Division of Water Quality (DWQ) recently received toxin test results and cyanobacteria cell-count concentrations from samples collected on October 9, 2018, and October 17, 2018, at or near Scofield Reservoir. Reports show a large variation in bloom growth, toxicity, and distribution in the reservoir over the two weeks of sampling.

Bloom conditions: October 9, 2018

Samples were collected at the outflow of Scofield Reservoir to the Price River to determine if cyanobacteria were exiting the reservoir. The monitoring crew saw cyanobacteria resembling small grass clippings distributed throughout the river. Blankets of cyanobacteria were seen throughout the reservoir, and every site showed a high presence of cyanobacteria. Overall, the bloom was more abundant than the previous week.

Bloom conditions: October 17, 2018

The monitoring crew observed cyanobacteria resembling sparse, small grass clipping distributed throughout the Price River. The bloom near the dam had dispersed significantly; however, green cyanobacteria was still observed along the banks. Samples were collected at the southeast angler due to visual evidence of a bloom. Samples were also collected at the Mountain View State Park Area due to visual observations of cyanobacteria resembling grass clippings. In general, cyanobacteria were present in isolated chunks and overall the bloom was less abundant than the previous week.

The Warning Advisory remains in effect for Scofield Reservoir.

Sample Locations and Sample Types

October 9, 2018

• Outlet stream from Scofield Reservoir/Price River (elbow-depth integrated composite sample)
• Near the dam (surface sample)

October 17, 2018

• Mountain View Boat Ramp (surface sample)
• Near dam (surface sample)
• Outlet stream from Scofield Reservoir/Price River (elbow-depth integrated composite sample)
• Southeast angler’s access (surface sample)

Toxin Test Results

Test results from the Utah Public Health Lab (UPHL) and Utah Department of Agriculture (UDAF) lab as noted.

October 9, 2018

• Outlet stream from Scofield Reservoir/Price River: <0.10 micrograms per liter (µg/L) of anatoxin-a (UDAF); 3.23 µg/L of microcystins (UDAF)
• Near the dam: 0.8 µg/L of anatoxin-a (UPHL); 1700 µg/L of microcystins (100x dilution) (UPHL)

October 17, 2018

• Mountain View Boat Ramp: 0.11 µg/L of anatoxin-a (UPHL); 0.77 µg/L of microcystins (UPHL)
• Near dam: <0.10 µg/L of anatoxin-a (UPHL); 0.96 µg/L of microcystins (UPHL)
• Outlet stream from Scofield Reservoir/Price River: <0.10 µg/L of anatoxin-a (UPHL); 0.53 µg/L of microcystins (UPHL)
• Southeast angler’s access: 0.12 µg/L of anatoxin-a (UPHL); >5 µg/L of microcystins (UDAF)

Cyanobacteria Cell-Count Concentrations

October 9, 2018

• Outlet stream from Scofield Reservoir/Price River: 5,774 cells per milliliter (cells/ml)
• Near the dam: 187,773,678 cells/ml

October 17, 2018

• Mountain View Boat Ramp: 8,795 cells/ml
• Near dam: 32,755 cells/ml
• Outlet stream from Scofield Reservoir/Price River: 744 cells/ml
• Southeast angler’s access: 67,003 cells/ml

Update October 13, 2018

The Division of Water Quality (DWQ) received cyanobacteria cell-count concentrations today for samples collected on Scofield Reservoir on October 2, 2018. Cyanobacteria cell-count densities at all three sample sites exceeded the recreation health-based threshold for a Warning Advisory.

• Scofield Reservoir outlet stream: 60,799 cells per milliliter (cells/ml)
• Scofield Reservoir near the dam: 1,231,490 cells/ml
• Madsen Bay Boat Ramp: 44,859 cells/ml

The Warning Advisory remains in place for Scofield Reservoir.

Update October 12, 2018

The Division of Water Quality (DWQ) recently received cyanobacteria cell-count concentrations for samples collected on Scofield Reservoir on September 20, 2018, and September 25, 2018. Cell counts at three of the four sampling locations exceeded the recreation health-based threshold of 20,000 cells per milliliter (cells/ml) for a Warning Advisory.

September 20, 2018 samples

• Scofield Reservoir near the dam: 50,478 cells/ml
• Scofield Reservoir southwest beach: 158,064 cells/ml

September 25, 2018 samples

• Scofield Reservoir near the dam: 734,081 cells/ml
• Scofield Reservoir outlet stream: 7,290 cells/ml

The Warning Advisory remains in place for Scofield Reservoir.

Update October 9, 2018

The Division of Water Quality (DWQ) visited six sites in or near Scofield Reservoir on October 2, 2018, and collected surface samples at three sites. Cyanobacteria accumulation was observed near the dam and at the Madsen Bay Boat Ramp. Cyanobacteria were observed in the Price River below the dam at Scofield; however, they were less abundant compared to the previous week.

While visual observations of bloom activity showed a decrease in cyanobacteria accumulations, microcystin levels continued to exceed the recreation health-based threshold for a Warning Advisory, and anatoxin-a levels at the Madsen Bay Boat Ramp exceeded the recreation health-based threshold for a Warning Advisory. Further dilutions by the lab will be necessary to quantify microcystin concentrations at two sample sites. Preliminary values could go even higher after these dilutions.

Toxin Test Results

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

• Scofield Reservoir outlet stream (Price River): <0.10 micrograms per liter (µg/L) of anatoxin-a; >5 µg/L of microcystin
• Near the dam: <0.10 µg/L of anatoxin-a; 6 µg/L of microcystin (10x dilution)
• Madsen Bay Boat Ramp: 0.48 µg/L of anatoxin-a; >5 µg/L of microcystin

The Warning Advisory at Scofield Reservoir remains in place.

Update October 1, 2018

The Division of Water Quality (DWQ) visited Scofield Reservoir on September 25, 2018, and collected surface samples at the reservoir outlet stream (Mud Creek) and near the dam.

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 high, particularly near the dam, which showed microcystin levels of >50 micrograms per liter (µg/L) after 10x dilution. Microcystin levels were >5 µg/L at Mud Creek. Both samples exceed the recreation health-based threshold for a Warning Advisory. The UDAF lab will perform additional dilutions to quantify microcystin concentrations. Levels could go higher after further dilutions.

Cyanobacteria accumulation was observed at all six monitoring sites. Bloom conditions resembling green grass clippings and green spilled paint were distributed throughout the water. Surface samples were collected from the bloom near the outlet of the reservoir (dam). Cyanobacteria particulates were also observed in the water of the outlet stream from Scofield Reservoir. Cyanobacteria accumulation appeared to be present throughout the majority of the reservoir, and conditions overall appeared to be much worse compared to the previous week.

DWQ monitoring crews will be collecting additional samples tomorrow, October 2, 2018.

The Warning Advisory remains in place for Scofield Reservoir.

Toxin Test Results

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

• Scofield Reservoir near the dam: anatoxin-a of <0.10 µg/L; microcystin of >50 µg/L (10x dilution)
• Scofield Reservoir outlet stream (Mud Creek): anatoxin-a of <0.10 µg/L; microcystin of >5 µg/L

Update September 27, 2018

The Division of Water Quality (DWQ) received cyanobacteria cell-counts for a sample collected on September 13, 2018, on the southwest beach of Scofield Reservoir. The lab tests found cyanobacteria cell-count densities of 164,551 cells per milliliter (cells/ml), which falls within the threshold for a Warning Advisory.

The Warning Advisory for Scofield Reservoir remains in place.

Update September 26, 2018

The Utah Public Health Lab (UPHL) performed additional dilutions on a sample collected from Scofield Reservoir on September 20, 2018. Final toxin results from the sample near the dam showed microcystin levels of 32 micrograms per liter (µg/L) after 10x dilution.

The Division of Water Quality (DWQ) visited Scofield Reservoir on September 25, 2018. Monitoring crews observed cyanobacteria at all six monitoring sites. Bloom conditions resembling grass clippings and green spilled paint were distributed throughout the water. DWQ observed cyanobacteria particulates in the outlet stream from Scofield Reservoir and collected samples at this location. Cyanobacteria accumulation was present throughout the majority of the reservoir and bloom conditions overall looked much worse than the previous week.

Follow-up samples were delivered to the appropriate labs.

Update September 25, 2018

The Division of Water Quality (DWQ) visited five sites at Scofield Reservoir on September 20, 2018, and collected samples at the southwest beach and near the dam. DWQ monitoring crews observed cyanobacteria at four of the five monitoring sites. Cyanobacteria appeared to be abundant and well-dispersed through the water column at Mountain View State Park, Madsen Bay Boat Ramp, and near the dam. Cyanobacteria were more distributed than the previous week and more abundant overall.

Microcystin levels at the Southwest Beach were below advisory thresholds, as were anatoxin-a levels near the dam. However, anatoxin-a levels at Southwest Beach and microcystin levels near the dam exceeded the recreation health-based threshold for a Warning Advisory. Microcystin levels of >5 micrograms per liter (µg/L) near the dam will require further dilutions to quantify microcystin concentrations, and preliminary values could go even higher after these dilutions.

The following sites displayed evidence of cyanobacteria accumulation:

• Southwest Beach: Consolidated green/blue cyanobacteria were observed in pools along the Southwest Beach shoreline. Water was turbid further out into the reservoir, so it was difficult to determine the extent of the bloom. DWQ collected a surface sample.
• Near the Dam: Green cyanobacteria resembling grass clippings were observed distributed through the water column. Cyanobacteria were dispersed, but abundant. DWQ collected an elbow-depth integrated composite sample.
• Mountain View State Park: Green cyanobacteria resembling grass clippings were observed distributed through the water column. Cyanobacteria were dispersed, but abundant.
• Madsen Bay Boat Ramp: Green cyanobacteria resembling grass clippings were observed distributed through the water column. Cyanobacteria were dispersed, but abundant.

Scofield Reservoir remains under a Warning Advisory.

Toxin Test Results (Utah Public Health Lab (UPHL)

• Southwest Beach: 0.13 micrograms per liter (µg/L) of anatoxin-a; 0.44 µg/L of microcystins
• Near the Dam: <0.10 µg/L of anatoxin-a; >5 µg/L of microcystins

Update September 21, 2018

The Division of Water Quality (DWQ) received test results today for samples collected on Scofield Reservoir on September 7, 2018. Microcystin levels for a surface sample near the dam were 9 times higher than the recreation health-based threshold for Danger Advisory, and cyanobacteria cell-count concentrations for the sample were almost 8 times higher than the threshold for a Danger Advisory. Anatoxin-a levels exceeded the recreation health-based threshold for a Warning Advisory.

Utah Department of Health.Utah Department of Environmental guidelines for a Danger Advisory include cell count densities greater than 10,000,000 cells/ml, microcystins levels greater than 2,000 µg/L, cylindrospermopsin levels greater than 8 µg/L, or anatoxin-a levels greater than 90 µg/L.

Toxin Test Results

Lab results from the Utah Public Health Lab (UPHL) and Utah Department of Agriculture and Food (UDAF) labs:

• Anatoxin-a: 0.31 micrograms per liter (µg/L) (UDAF)
• Microcystin: 18,000 µg/L (UPHL)

Cyanobacteria Cell Count Concentrations

78,800,669 cells per milliliter (cells/ml)

Update September 20, 2018

The Division of Water Quality (DWQ) visited five sites at Scofield Reservoir on September 13, 2018. The monitoring crew observed cyanobacteria that looked like grass clippings at four of five monitoring sites. Cyanobacteria were also observed throughout the water column near the dam and Mountain View State Park area, but they were sparse and well-distributed. The Madsen Bay Boat Ramp area, however, had a thicker presence of cyanobacteria dispersed in the water column. Cyanobacteria accumulation was greatest at the southwest beach.

One sample was collected at the southwest beach area and delivered to the lab.

Toxin-test results received by DWQ from the Utah Public Health Lab (UPHL) showed low anatoxin-a and microcystin levels, but the anatoxin-a levels still exceeded the recreation health-based threshold for a Warning Advisory.

Toxin Test Results

• Surface sample collected at the southwest beach.
• Anatoxin-a: 0.12 micrograms per liter (µg/L)
• Microcystin: 0.38 µg/L

The Warning Advisory for Scofield Reservoir remains in place.

Update September 10, 2018

The Division of Water Quality (DWQ) visited five sites at Scofield Reservoir on September 7, 2018. The southern end of the reservoir did not show signs of a bloom, but a thick green bloom resembling spilled paint was observed near the dam. Conditions at the Mountain View Boat Ramp had improved, but there were still some sparse, evenly distributed cyanobacteria floating through the water column. The Madsen Bay Boat Ramp still displayed signs of a bloom, but the cyanobacteria were fairly dispersed.

DWQ collected samples near the dam for further lab analysis.

Update August 27, 2018

The Division of Water Quality (DWQ) collected samples at two locations on Scofield Reservoir on August 20, 2018. According to Utah Department of Agriculture and Food (UDAF) lab results, both locations were well below the recreation health-based threshold for a Warning Advisory for toxins. However, the Madsen Boat Ramp showed cyanobacteria cell-count concentrations that exceeded the threshold for a Warning Advisory. Water conditions appeared to be better than the previous week.

Scofield Reservoir remains under a Warning Advisory.

Sample Location and Sample Type

• Madsen Boat Ramp (surface sample)
• Open Water (elbow-depth integrated composite sample)

Cyanobacteria Cell-Count Concentrations

• Madsen Boat Ramp: 97,357 cells per milliliter (cells/ml)
• Open Water: 2,703 cells/ml

Toxin Test Results

• Madsen Boat Ramp: <0.1 micrograms per liter (µg/L) of anatoxin; <0.1 µg/L of microcystins
• Open Water: <0.1 µg/L of anatoxin; <0.1 µg/L of microcystins

Update August 15, 2018

Lab results from samples collected on August 6, 2018, at the Madsen Boat Ramp and in the open water at the reservoir showed high cyanobacteria cell-count concentrations at the boat ramp (200,794 cells per milliliter (cells/ml), densities that exceed the recreation health-based threshold for a Warning Advisory. All other test results were below the advisory level.

Warning Advisory for Scofield 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. 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 Locations and Sample Types

• Madsen Boat Ramp (surface sample)
• Open water (elbow-depth integrated composite sample)

Cyanobacteria Cell Count Concentrations

• Madsen Boat Ramp: 200,794 cells per milliliter (cells/ml)
• Open water: 13,129 cells/ml

Toxin Test Results

Test results are from the Utah Public Health Lab (UPHL)

• Madsen Boat Ramp: <0.10 micrograms per liter (µg/L) of anatoxin-a; 0.16 µg/L of microcystin
• Open water: <0.10 micrograms per liter (µg/L) of anatoxin-a; 0.14 µg/L of microcystin

Update August 7, 2018

The Division of Water Quality (DWQ) collected two samples at Scofield Reservoir on July 30, 2018. While cyanobacteria cell-count concentrations continue to exceed the recreation health-based threshold for a Warning Advisory, their densities were significantly lower than the July 23, 2018, samples, which contained cell counts in excess of 23 million cells per milliliter (cells/ml) and 12.8 million cells/ml near the dam and Madsen Boat Ramp, respectively.

Toxin levels remain well below the health-based advisory threshold with the exception of one anatoxin-a level in exceedance of the threshold.

Warning Advisory for Scofield 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. 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 Locations and Sample Type

• Scofield Reservoir Mountain View Boat Launch (surface sample)
• Scofield Reservoir Open Water (Elbow-depth integrated composite sample)

Cyanobacteria Cell-Count Concentrations

• Scofield Reservoir Mountain View Boat Launch: 1,365,020 cells per milliliter (cells/ml)
• Scofield Reservoir Open Water: 61,765 cells/ml

Toxin Test Results

Utah Public Health Lab (UPHL) test results showed one exceedance of anatoxin-a at the Mountain View Boat Launch, but otherwise, the samples were below the recreation health-based threshold for a Warning Advisory.

• Scofield Reservoir Mountain View Boat Launch: 0.11 micrograms per liter (µg/L) of anatoxin-a; 0.17 µg/L of microcystin
• Scofield Reservoir Open Water: <0.1 µg/L of anatoxin-a; 0.26 µg/L of microcystin

Update August 1, 2018

Lab results from samples collected at three locations on July 23, 2018, showed very high cyanobacteria cell-count levels at all sampling sites. Cell counts near the dam and at the Madsen Boat Ramp were approximately 23 million cells per milliliter (cells/ml) and 13 million cells/ml, respectively. While these cyanobacteria cell-count densities exceed the recreational health-based thresholds for a Danger Advisory, bloom conditions improved this week, and toxin levels continue to remain low. After careful consideration of the available data, the Southeast Health Department determined that the current Warning Advisory continues to be protective of human and animal health given bloom conditions in the reservoir.

Warning Advisory for Scofield 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. 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 Locations and Sample Type

• Mountain View Boat Launch (surface sample)
• Reservoir near Dam (elbow-depth, integrated composite sample)
• Madsen Boat Ramp (elbow-depth, integrated composite sample)

Cyanobacteria Cell-Count Concentrations

• Mountain View Boat Launch: 7,432,688 cells per milliliter (cells/ml)
• Reservoir near the Dam: 23,363,473 cells/ml
• Madsen Boat Ramp: 12,843,338 cells/ml

Toxins Test Results

• Mountain View Boat Launch: 0.8 micrograms per liter (µg/L) of anatoxin-a; 0.21 µg/L of microcystin
• Reservoir near the Dam: 0.7 µg/L of anatoxin-a; 1.3 µg/L of microcystin
• Madsen Boat Ramp: 0.41 µg/L of anatoxin-a; 0.23 µg/L of microcystin

Update July 20, 2018

The Division of Water Quality (DWQ) received toxin test results on July 19, 2018, from samples collected on July 16, 2018. Cyanobacteria cell-count concentrations were quite high, particularly at the Madsen Boat Ramp, and exceeded recreational health-based thresholds at all sample sites. While cell-count concentrations increased between July 10 and July 16, 2018, toxin levels overall were below the recreational health-based threshold. The exception is the Madsen Boat Ramp, which continues to exceed the threshold for anatoxin-a.

DWQ will return on July 23, 2018, to collect additional samples.

Warning Advisory for Scofield 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. 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 Locations and Sample Type

• Mountain View Boat Launch (surface sample)
• Reservoir near the Dam (elbow-depth integrated composite sample)
• Madsen Boat Ramp (elbow-depth integrated composite sample)

Cyanobacteria Cell-Count Concentrations

Cyanobacteria cell-count densities greatly exceeded recreational health-based thresholds at all sample sites.

• Mountain View Boat Launch: 1,691,308 cells per milliliter (cells/ml)
• Reservoir near the Dam: 6,286,796 cells/ml
• Madsen Boat Ramp: 39,611,935 cells/ml

Lab Toxin Test Results

Samples were submitted to the Utah Public Health Lab (UPHL) and Utah Department of Agriculture and Food (UDAF) labs for enzyme-linked immunosorbent assay (ELISA) testing. Results listed below are from UDAF. Toxin levels exceeded recreational health-based thresholds for anatoxin-a at the Madsen Boat Launch.

• Mountain View Boat Launch: <0.1 micrograms per liter (µg/L) for anatoxin-a; <0.1 µg/L for microcystin
• Reservoir near the Dam: <0.1 µg/L for anatoxin-a; 0.3 µg/L for microcystin
• Madsen Boat Ramp: 0.37 µg/L for anatoxin-a; 0.84 µg/L for microcystin

Update July 16, 2018

DWQ received cell-count concentrations late Friday afternoon for samples collected July 10, 2018, on Scofield Reservoir. All samples were dominated by or exclusively Dolichospermum, a genus of cyanobacteria known to produce toxins.

With the exception of the North Arm sample, cyanobacteria cell-counts at sampling locations exceeded recreational health-based thresholds. Counts were particularly high at the Frandsen Boy Scout Camp at approximately 7 million cells per milliliter (cells/ml). Increasing cell-count densities indicate the bloom is expanding in the reservoir.

•  Madsen Boat Ramp: 1,460,332 cells/ml
•  Mountain View Boat Ramp: 1,375,649 cells/ml
•  North Arm: 16,667 cells/ml
•  Frandsen Boy Scout Camp: 6,900,782 cells/ml

The Utah Department of Agriculture and Food (UDAF) lab analyzed the July 10, 2018, sample from the Madsen Boat Ramp and found anatoxin-a levels of 0.16 micrograms per liter (µg/L), which exceeds recreational health-based thresholds.

Warning Advisory for Scofield 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. 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 July 13, 2018

During July 5, 2018, sampling at Scofield Reservoir, a Division of Water Quality (DWQ) monitoring crew observed that the bloom at the Mountain View Boat Ramp was denser and thicker than the previous week. Toxin test-strip results were negative for both microcystins and anatoxin-a.

The boat ramp at the northwest corner of the reservoir (Madsen Bay Boat Ramp) also showed a heavy bloom presence. Toxin test-strip results from the boat ramp were non-detect for microcystin but positive for anatoxin-a at 0.1 micrograms per liter (µg/L), a level later confirmed by the Utah Public Health Lab (UPHL).

Cyanobacteria cell-count concentrations from the the July 5, 2018, samples at both locations exceeded health-based thresholds, with over 3.4 million cells per milliliter (cells/ml) at Madsen Bay Boat ramp and >250,000 cells/ml at Mountain View Boat Ramp.

The monitoring crew investigated the Boy Scout Camp during its July 10, 2018 visit. The phycocyanin sensor reading was extremely high at the camp, but toxin test strips came back negative for both microcystin and anatoxin-a. A follow-up toxin strip test from the Madsen Bay Boat Ramp on July 10, 2018, showed the continued presence of anatoxin-a at <0.4 µg/L.

Toxin test strip results  from July 12, 2018, samples at the Boy Scout Camp and the Madsen Bay Boat Ramp also came back negative, but  microscope examination of water samples at these sites appeared to confirm cyanobacteria. In addition, the DEQ District Engineer and Southeast Health Department officials observed visual evidence of cyanobacteria in a few isolated pockets at the upstream inlet of Madsen Bay.

The Madsen Boat Ramp sample was sent to UPHL and the Utah Department of Agriculture and Food (UDAF) lab for anatoxin-a testing. DWQ will return to Scofield Reservoir on July 16, 2018, to collect additional samples and track bloom activity.

Based on cyanobacteria cell-count concentrations, the detection of anatoxin-a at sampling sites, and visual observations, the Southeast Health Department has issued a Warning Advisory for Scofield Reservoir.

While some areas of Scofield Reservoir are not currently affected by visible blooms, algae may move or disperse depending on temperature, wind, and weather. Recreationists are advised to be mindful of conditions, as they may change over the course of the day.

Warning Advisory for Scofield 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. 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

According to the Southeast Utah Health Department, city drinking water and Price River Water Improvement District (PRWID)-supplied water is treated and is safe to drink. Canal water is currently unaffected by any residual bloom.

Cyanobacteria Cell-Count Concentrations

All cyanobacteria present in the July 5, 2018 samples were identified as Dolichospermum.

• Mountain View Boat Ramp: 253,474 cells per milliliter (cells/ml)
• Madsen Bay Boat Ramp: 3,428,860 cells/ml

Update July 10, 2018

Division of Water Quality (DWQ) scientists collected samples at four locations on Scofield Reservoir on July 5, 2018. Two locations had no visible blooms and showed very low values on the crew’s phycocyanin sensor, a probe used to detect, quantify, and monitor cyanobacteria levels. Two other sample locations had visible blooms, and phycocyanin sensor readings at these locations indicated cyanobacteria cell concentrations that warranted sampling.

The Mountain View boat launch area had a visible bloom in the shallows near the boat ramp and around the dock. The DWQ monitoring crew took a surface sample for cyanotoxins and cyanobacteria identification and cell-count concentrations.

The crew observed the greatest cyanobacteria concentrations at the boat launch in the northwest corner of the reservoir. DWQ took two samples: surface and integrated (elbow-depth, integrated composite) for cyanotoxins and cyanobacteria identification and cell-count concentrations.

DWQ scientists ran toxin test strips on the samples on July 6, 2018, that yielded conflicting results for microcystin and anatoxin. The samples were delivered to the Utah Public Health Lab and Utah Department of Agriculture and Food (UDAF) lab for further testing. DWQ shipped the phytoplankton samples to Phycotech on July 9, 2018, for cyanobacteria cell-count concentrations and taxa identification. DWQ should have these results back either July 11 or July 12, 2018.

UPHL tests on the samples detected 0.1 micrograms per liter (µg/L) of anatoxin-a at the northwest boat launch, which exceeds the recreational health-based threshold and meets Utah Department of Health/Department of Environmental Quality guidance recommendations for a Warning Advisory. While the lab also detected microcystin at the northwest boat launch, levels were below the recreational health-based threshold. The Mountain View boat launch was non-detect for all toxins.

DWQ monitoring crews will be conducting follow-up sampling at Scofield early this week as bloom photos and HABs-buoy data indicate increasing levels of cyanobacteria in the reservoir.