Lake Darling not fit for swimming

BRIGHTON — Lake Darling is not fit for swimming right now.

Every week this summer, the Iowa Department of Natural Resources has issued an advisory for the beach at Lake Darling State Park.

From Memorial Day to Labor Day, the DNR conducts weekly monitoring of 39 state park beaches.

Ingrid Gronstal, water program director for the Iowa Environmental Council, said that the DNR has issued four microcystin advisories and three E. coli advisories for the Lake Darling beach.

In the June 25 and July 2 reports, both types of advisories were issued for Lake Darling.

“E. coli is bacteria and is an indicator for other pathogens usually coming from animal or human manure sources,” Gronstal said. “Microcystin is a toxin produced by certain algae blooms. The water is pretty green, and that’s indicative of an algae bloom and could produce microcystin toxins that make people sick.”

She said that sickness is their primary concern.

“Sometimes, people don’t know they’ve been exposed because they can mimic other illnesses,” Gronstal said. “You can have a cough, shortness of breath or (gastrointestinal) disruption.

“A lot of people think they maybe got too much sun or that they drank or ate too much, when really you’ve had poisoning from a toxin.”

Also, pets, particularly dogs, are at risk for microcystin exposure.

“In the summer of 2019, there were a lot of national news stories about dogs swimming in areas with high microcystin and dying just a few hours later,” she said. “Pets tend to lick water off their fur and are attracted to scummier areas than people might be swimming in. It was really tragic and definitely avoidable.”

Although the beach is not closed, there is a small sign posted warning that swimming there is strongly discouraged.

Gronstal wants the state to make the signs more prominent.

“One thing I’ve noticed is that the warning signs are pretty easy to walk past,” she said. “I also noticed that a lot of the people who use this park are speaking Spanish, and the signs are not in Spanish at all. The advisory should be communicated in a way that all users understand the risks.”

Gronstal explained that both bacteria and algae blooms are formed form excess nutrients — nitrogen and phosphorus — in the water. A lot of that comes from fertilizer sources.

“The nutrient problem across the state is primarily due to not enough conservation practices on the land and too many concentrated farm operations,” she said.

She noted that Washington County has the highest number of hogs in the state, but also has the highest percentage of cover crops in the state, which helps mitigate the nutrient issues.

“I think you’re seeing the number of hogs outstripping the number of conservation practices being put on the landscape,” Gronstal said.

She said that the issue is a balancing act between public and private land interests.

“We try to advocate for is a balance of private and public interests in our land and natural resources,” she said. “We’re definitely not advocating no farms. It’s just the livestock facility regulations right now are very permissive toward the building of facilities and adding more animals.

“Having tighter controls on how many animals, where the animals are sited and how much manure gets distributed would go a long way toward improving water quality.”

Lake Darling underwent a $16 million restoration effort that was completed in 2014. Part of that project was to remediate some water quality concerns.

“Now, we’re still seeing advisories every week, and the water quality is clearly very poor,” Gronstal said. “This is a beautiful state park and a beautiful lake. We want to have people come here and recreate.”