‘Like a rotten egg-type smell’
It’s about to warm up in Wisconsin this weekend. Watch out for stinky ice. Yes, stinky ice.
GREEN BAY - You don’t develop a reputation for having the best sheets of ice in northeastern Wisconsin by letting something like stinky ice get the better of you.
You read that right: Stinky ice.
It’s a thing. A brownish-yellowish, bubbling, smelly thing that Green Bay’s Parks Department contends with and works to avoid each winter when it creates ice rinks in seven different parks throughout the city, said James Andersen, assistant parks director.
“It kind of smells almost like a rotten egg-type smell,” Andersen said. “It’s one of those Wisconsin mysteries where if you’re an ice skater or hockey player, you’ve probably seen it in the past and wondered what it is. Everyone has a slightly different theory.”
So how does a sheet of ice turn yellowish and stinky? It takes a bacterium native to Wisconsin, some partially thawed soil, a clear sheet of ice and sun, Andersen explained. The bacterium flourishes in the soil when the ice sheet cuts off access to oxygen.
“When the ground isn’t quite totally frozen, when you put a sheet of ice on top of it, the sun goes through the ice and warms up the earth and creates a bacterium that ... doesn’t need oxygen,” Andersen said. “It starts to almost bubble up in the ice and methane comes through.”
An explainer on Green Bay’s website makes clear the city’s not the source of the offending smell: “Although harmless to humans and clothing, the bacterium stinks. This is thanks to Mother Nature again.”
The 2020-21 winter season has been stinky icefree, a silver lining to the frigid month of February.
Andersen said conditions could change with this week’s warmer weather.
“Luckily this year, we had a huge deep freeze and we have nice, thick ice right now. Essentially we have no stinky rink right now,” he said. “Starting with the warmer temperatures, we should be good with the thicker ice, but you never know. We might see some bubble up a bit.”
Andersen said Parks Department staff have learned the key to avoiding stinky circumstances is to wait to lay down the first layers of water until the ground is frozen solid. It’s part of why the department waits a little longer in the season to make ice.
“People call us before Christmas, or even when it starts getting a little colder and they’re like ‘Hey, how come you don’t have sheets of ice ready to go yet for Christmas?’” Andersen said. “Until that ground is really frozen, you want to make sure you wait.”