A popular lake in the Twin Cities suburb of Edina isn't safe right now.
High levels of blue-green algae have been detected in Lake Cornelia creating "public health concerns," the city said in a news release.
Officials are warning people to stay out of the water because the algae brings with it high levels of microcystin – a toxin produced by the freshwater bacteria that can be harmful to human health and can even kill dogs.
If this sounds familiar, that's because high microcystin toxin levels were also detected in the lake last September.
Conservation Minnesota says there are a number of reasons Lake Cornelia continues to have problems. Because it lies on a large watershed, over 1,000 nearby acres drain into it. With that comes a lot of pollution run-off from city streets, parking lots, and lawns in the area. Plus, at its deepest point, the lake is only 7 feet – making it susceptible to algae blooms.
Dangers of blue-green algae
Blue-green algae isn't actually an algae, but a freshwater bacteria called cyanobacteria.
With foul-smelling blooms that resemble pea soup, it generally presents during warm weather when the water is stagnant and rich in nutrients.
Exposure to the toxins can be harmful to liver and kidney functions, with symptoms of poisoning including jaundice, shock, abdominal pain, weakness, nausea, vomiting, severe thirst and a rapid pulse.
Pets are more at risk because they don't know better not to drink the water. Blooms have sickened humans and killed several dogs in recent years.
Addressing the problem
The Star Tribune notes the lake's ongoing issues have even gotten attention from the federal government. The lake’s north basin is on the Environmental Protection Agency’s “impaired waters” list for failing to meet water quality standards.
Officials say the lake is treated for algae up to twice per year by lake management companies, and it will continue to be monitored until toxin levels drop.
“The City is working to minimize invasive aquatic plants in Lake Cornelia and promote the growth of a healthy native aquatic plant population to ‘tie-up’ phosphorus, making less of it available for cyanobacteria and other algae to grow,” Edina's Water Resources Coordinator Jessica Vanderwerff Wilson said in the release.
But Conservation Minnesota warns that improving the lake is going to take a community effort to reduce run-off pollution and try to find the best way to keep it clean.
The group says there are 31 homeowners directly on the lake and many more in its water basin.
Lake Cornelia is also a popular fishing destination because of its abundant population of Yellow Perch, the DNR says. And part of the lake shore is next to Rosland Park, which sees many families on its playground, walking paths and picnic areas.