Advisory issued for area of Boysen Reservoir

Wyoming DEQ, in cooperation with the Wyoming Department of Health and Fremont County Emergency Management is putting out notice that the Wyoming Dept. of Health has issued a recreational use advisory for Boysen Reservoir due to elevated densities of cyanobacteria at the Marina on the northeast side of the reservoir near the Brannon Boat Ramp.

This is an annual occurrence and in any areas where cyanobacteria is present, it can be seen in the water. Be aware that swimming activities in this area are not advised. Do not let that deter you from taking your activities to another area of the park and water.

Lindsay Patterson with Surface Water Quality Standards for the Wyoming Department of Environmental Quality provided a brief chronology.

On Monday, July 23, DEQ received notice from the Wyoming Dept. of Health that a veterinarian had examined an ill dog and suspected the animal may have come into contact with a cyanobacteria bloom at Boysen Reservoir near the Tough Creek area.

On Tuesday, July 24, DEQ staff investigated and collected samples at the reservoir. They did not observe any cyanobacteria blooms at Tough Creek campground, but collected cyanotoxin samples at that area. DEQ staff also visited the marina on the northeast side of the reservoir as well as Fremont Bay on the west side of the reservoir. A small bloom was observed at the marina and samples were collected. No visible blooms were observed at Fremont Bay and no samples were collected.

On Friday, July 27, results were received indicating that cyanobacteria cell densities were very high in the samples collected at the marina and above the 20,000 cells/mL threshold identified in the Wyoming DEQAction Plan. This information was relayed to the Dept. of Health and Boysen State Park.

According to Boysen Marina staff, advisory signs were posted.