Update September 14, 2018
The Division of Water Quality (DWQ) visited five sites on Pineview Reservoir on September 10, 2018. Water conditions at the west boat ramp and Northwest shore had greatly improved since DWQ’s last visit and showed no signs of a cyanobacteria bloom.
Cyanobacteria cell-count concentrations from the September 4, 2018, surface sample at the Northwest shore were 6,537,027 cells per milliliter (cells/ml), which exceeds the recreation health-based threshold for a Warning Advisory. However, it appears that the bloom dissipated during the week between these samples. The cell-count densities from the September 4, 2018, sampling provides additional lines of evidence to support the decision by the Weber-Morgan Health Department to issue a Warning Advisory for the reservoir over the Labor Day weekend.
The monitoring crew collected follow-up samples at both the west boat ramp and Northwest shore for delivery to the lab for further analysis. No bloom material was observed on or within the water at Middle Beach, Cemetery Point, and Anderson Cove.
Update September 7, 2018
The Weber-Morgan Health Department lifted the Warning Advisory for Pineview Reservoir after toxin-test results from samples taken today fell below detection limits. Health Department staff took samples today at the five major public access points to the lake, and none met the threshold for a Warning Advisory.
The department removed warning signs a the reservoir but encourages the public to stay clear of areas with algae. Health officials will continue to monitor and sample the reservoir for the foreseeable future.
Update September 5, 2018
The Division of Water Quality (DWQ) visited five monitoring sites and collected two surface samples at Pineview Reservoir on September 4, 2018. Visible blooms were observed at the West Boat Ramp as well as the Northwest Point, with green surface scum floating on the surface at both locations. No surface scums were visible at the other three sites, but there was a green tint to the water. Water levels were down throughout the reservoir.
Toxin test strip results were non-detect for anatoxin-a at the West Boat Launch and invalid for anatoxin-a at Northwest Point. Microcystin levels were <2.5 micrograms per liter (µg/L) at the West Boat Launch and approximately 5 µg/L at Northwest Point. The West Boat Launch microcystin levels exceeded the recreation health-based threshold for microcystin. Samples were sent to the labs for further toxin analysis.
The Warning Advisory at Pineview 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.
Update August 31, 2018
The Weber-Morgan Health Department (WMHD) has reported a widespread harmful algal bloom (HAB) at Pineview Reservoir. Most of the algal accumulation is near Windsurfer Beach on the northwest side of the reservoir, but multiple bays appear to also be impacted. Samples will be collected over the next few days to determine cyanobacteria cell-count concentrations and toxin levels.
WMHD has issued a Warning Advisory for Pineview Reservoir and will post Warning Advisory signs around the reservoir. Pineview Reservoir reopened late this afternoon after closure due to the Avon Fire in Ogden Valley.