Officials with the Indiana Department of Environmental Management say testing has revealed a high cell count of blue-green algae in waters at the Hardy State Lake Recreation Area in Scottsburg. The high count prompted the agency to issue an alert to bathers.
Blue-green algae, also known as cyanobacteria, are found in freshwater and grow best in hot, dry weather. The algae is usually harmless, but can be linked to some adverse health effects for humans and pets.
IDEM analysts identified 120,000 cells of blue-green algae per milliliter in samples from Hardy Lake. For protection of human health, the World Health Organization uses a guideline level of greater than 100,000 cells per milliliter for a high risk health alert in recreational waters.
The Indiana Department of Natural Resources posted a recreation alert notice on the official webpage for Hardy Lake, in addition to signs at the physical site.
Cyndi Wagner, Chief of Targeted Monitoring Section with IDEM, said the advisory should not be cause for alarm.
"It's just to make [people] aware of the situation," Wagner said. "Hardy Lake last year had alerts for almost the entire summer. This is not an uncommon phenomenon, unfortunately, that we're finding."
Swimming and boating will still be permitted in the lake. The DNR advises patrons to avoid contact with visible algae as much as possible and to refrain from drinking the water, per State Department of Health guidelines,. They recommend showering after swimming and keeping pets out of the water.
Dr. Ronald Turco, professor at Purdue University and director of the Indiana Water Resources Research Center, advises patrons to avoid contact with visible algae as much as possible.
"You see the scummy algae on the surface, you should stay out of it," Turco said. "It's fairly easy to identify, that's the tricky part – sometimes you don't get the really significant growth on the surface that you would be warned."
"You should check the signage, check with IDEM, and pay attention to the postings, basically."
Hardy Lake will be re-tested every two weeks while the levels remain above the threshold.
Testing is part of an annual evaluation of state parks and recreation areas to monitor algae levels in the water. It's a collaborative effort between IDEM, the DNR and State Department of Health. The initial two weeks of sampling concluded on Tuesday. Officials will return to test the same areas monthly, unless findings indicate a need for a closer look. Results of sample analysis are posted on algae.in.gov.
