Herriman City closes Blackridge Reservoir after algae-related toxin found in Jordan River

SALT LAKE COUNTY, Utah -- The Salt Lake County Health Department is urging residents to avoid getting into the Jordan River after levels of an algae-related toxin were detected, and Herriman City has closed Blackridge Reservoir pending water test results.

While the health department has not closed any bodies of water in Salt Lake County, Herriman City announced Friday that Blackridge Reservoir will be closed until further notice as water samples are taken and tested.

Initially the city announced a restriction on swimming, but later Friday night they updated the advisory to say they are closing the reservoir completely "in the essence of safety, and as we take precautions, test the water and await sample results."

According to a press release issued Friday, test results from Friday showed 0.1 micrograms per liter of an algae-related toxin called anatoxin in the Jordan River.

The EPA "action level" for this toxin is any detection of its presence, so health officials are urging residents to avoid getting into the water and to keep their pets out as well. However, surface activities like boating are still considered low-risk.

"Toxins present at this level have not been shown to present a health threat to people on the surface of the river, such as while kayaking or boating," the press release states.

The samples that showed toxins were taken in the Jordan Narrows, where the Jordan River enters Salt Lake County, however health officials are advising residents to be cautious regarding the entire river because algae and toxins can spread quickly.

Warning signs will be posted at Wheeler Farm in Murray and Blackridge Reservoir in Herriman, but health officials say "no potentially affected water bodies in Salt Lake County are closed to access at this time." While the county has not closed any bodies of water, Herriman City has closed Blackridge Reservoir.

Health officials will continue to monitor the river and provide updates.

The press release states:

"Although blue-green algae are a natural part of many freshwater ecosystems, under the right conditions they can expand rapidly. High levels of nutrients in the water, combined with warm temperatures, abundant sunlight, and calm water, can promote growth, resulting in blooms that consist of cyanobacteria (often referred to as blue-green algae), a type of bacteria that can create toxins that pose a risk to humans and animals.

Symptoms of exposure include headache, fever, diarrhea, abdominal pain, nausea and vomiting, and sometimes allergic-like reactions from skin contact.

For concerns about possible human exposure, call the Utah Poison Control Center at 800-222-1222 or contact your health care provider."