Update September 14, 2018
The Division of Water Quality (DWQ) observed a small, localized harmful algal bloom at Jordanelle Reservoir on September 11, 2018, during routine E. coli monitoring. The monitoring crew collected an elbow-depth integrated sample. Toxin strip-test results showed anatoxin-a levels at approximately 2.5 micrograms per liter (µg/L), which exceeds the recreation health-based threshold for a Warning Advisory. The toxin strip test was non-detect for microcystin.
The bloom was not visible on the surface of the water, but the DWQ monitoring crew noticed a small, bright green patch of algae on the shore. It was hard to tell if the cyanobacteria were dispersed through the water column because the water was very turbid. The crew collected E. coli samples from two other areas of the reservoir and did not observe any indicators that the bloom was widespread at the reservoir; rather, it appeared to be localized near Aqua Cove and Boat Rental Beach.
Samples have been sent to the labs to further toxin analysis, cell-count concentrations, and taxa identification.