The dangerous blue-green algae in Milwaukee's Veterans Park lagoon continues to pose a risk to human and animal health. Last weekend, organizers of a dragon boat festival moved the event elsewhere because of toxins created by the algae. And this coming weekend, water skiers had planned to compete in a two-day competition.
The water ski event was canceled Wednesday, due to the water's condition.
Todd Miller is with UWM’s Zilber School of Public Health. He and his team have been testing the lagoon regularly this summer. Miller says its toxicity has varied, but has consistently been higher than the EPA’s cutoff for recreational activity.
“Yesterday (Monday), we had a sample in the morning and one in the afternoon, which were both greater than ten-fold the EPA recreational limit,” Miller explains.
The algae forms a toxic, slimy, sometimes fluorescent-hued sheen on the water's surface. He says if you swallow the water, "symptoms are felt within hours, if not minutes, actually (mirroring) those of flu-like illness, gastrointestinal infections...things like diarrhea, upset stomach, headache with no fever."
Miller says he was concerned when he learned Milwaukee County planned to drive a boat around the lagoon to aerate -- or break up -- the algae.
“There’s no examples of aeration causing the toxin levels to go down, in fact the toxins are very resistant to degradation. So aeration is unlikely to destroy the toxins at all. And there are examples of people having inhalation exposure." He adds, "Aerosols are more likely to be created when you’re stirring up the water either through aeration or boating."
"My boss tells me they (a crew to aerate the lagoon) come down every morning, kind of around sunrise I think, and they churn it up, zipping back and forth,” Michael Wetzel says. He manages the paddle boat and canoe business at the lagoon.
Wetzel says he was warning customers to stay out of the water long before toxic algae was present. “We get a lot of people asking about swimming, 'Is the water safe to swim?' And we say we don’t recommend that."
On August 1, the Milwaukee Health Department issued a news release warning the public to stay out of the lagoon. The department posted two temporary signs, while waiting for Milwaukee County to post permanent warnings.
There are two warning signs up at the lagoon, one on the life jacket bin and one on the rental kiosk.
Todd Miller says there are ways to manage toxic algae. However, as County workers trim tall grasses and spray weeds along the lagoon’s edge, he says they are unknowingly contributing to the toxic algae's growth.
“We like to see the waterfront (so) we don’t want cattails and submerged grasses to block our view. But when you remove those things, you remove the competition for the blue-green algae for nutrients,” he explains. “So it’s really this decision of do you want the toxic blue-green algae or do you want submerged grasses that may block your view of the waterway.”
Miller says the lagoon points to a larger problem with blue-green algae. "By all measures it would appear we haven’t managed the water body as we should. There are no submerged grasses here to act as a filter. All the runoff is free to go directly into this water body."
"There are no federal laws or state laws that require regular testing for blue-green algae or their toxins in waterways,” he says.