After the Utah County Health Department reopened Lincoln Beach and its marina on the eastern shores of Utah Lake on Thursday, signs that used to read “DANGER” now say “WARNING.”
It’s an upgrade that comes nearly a month after the department closed the area, including to swimmers, paddlers and sailboaters, due to toxic blue-green algal bloom conditions.
Though test results showed that cyanobacteria concentrations in the lake had dropped low enough for the area to reopen, the levels are still above the threshold for safe contact, according to a news release from the health department.
“Technically it is reopened, so people, you know, they can go and put their boats in the water,” Aislynn Tolman-Hill, a spokeswoman for the health department, told The Salt Lake Tribune. “But it would not be advisable to be getting in the water — so swimming would not be advised.”
A sample taken June 25 at the Lincoln Beach marina showed cyanobacteria density was 14 times higher than a sample taken June 20 — indicating a quickly deteriorating concentration, according to the Utah Department of Environmental Quality. Concentrations of a particularly hazardous cyanobacteria, known as Dolichospermum, spiked to 36 million cells per milliliter, nearly four times the threshold for a “danger” advisory, prompting the closure.
The cell concentrations are now below 10 million cells per millimeter, according to the health department.
Blue-green algae are natural parts of many freshwater ecosystems, but high levels of nutrients in the water, combined with high temperatures and calm water, can promote rapid growth. High concentrations of blooms, which consist of cyanobacteria, then pose a risk to human health.
“When we’re experiencing long periods of dry, hot weather like we have been, and stagnant heat where we don’t have a lot of storms and things that can kind of churn up the water — that’s certainly the situation we have been in — it’s kind of the perfect environment for that bacteria to grow,” Tolman-Hill said.
Exposure to those toxins can lead to rash, stomach ache, headache, diarrhea and more serious symptoms, said Tolman-Hill. Dogs are particularly at risk and have died after swimming in the infected waters.
This isn’t the first time algae have prompted closures. In July 2016, the blooms spread across 90 percent of the lake, forcing the Utah Department of Health to close it completely.
The Division of Water Quality will continue to monitor the conditions at Lincoln Beach with new samples, and its algal program posts periodic updates at habs.utah.gov.
People who are concerned about possible exposure to the toxic water should contact their doctor or the Utah Poison Control Center at 800-222-1222.
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