Don’t Worry, That Magnesium Chloride Highway De-Icer Isn’t Going To Kill All Of Our Fish

***For all things Wyoming, sign up for our daily newsletter***

By Mark Heinz, Outdoors Reporter
[email protected]

Magnesium chloride highway deicer potentially poisoning fish has raised some concerns in Montana, but that shouldn’t be a problem in Wyoming, a biologist says.

Magnesium chloride runoff from icy Montana highways into roadside fisheries “was an issue we’ve addressed several times over the years,” said Trevor Selch, a fisheries pollution control biologist at Montana Fish, Wildlife and Parks , opposite Cowboy State Daily.

The chemical can be toxic to fish. And while there haven’t been any major deaths in the Big Sky State, there was quite a scare a few years ago, he said.

“A few years ago we literally dumped the entire cargo (magnesium chloride deicer) halfway down a river,” he said. “We investigated immediately and even used sentinel fish in cages, sampled benthic macroinvertebrates and saw no effects. I’m not saying there aren’t any, just hard to spot.”

Wyoming has never had such spooky incidents, said Alan Osterland, chief of fisheries for Wyoming’s game and fish department.

“We are not aware of any adverse effects of mag-chloride applications on state roads in terms of fish or watershed health,” he said.

expensive stuff

The Wyoming Department of Transportation uses magnesium chloride deicer on roads, bridges and highways, but only sparingly, agency spokesman Cody Beers told Cowboy State Daily.

That’s because it’s expensive, he said.

“Magnesium chloride has many of the same properties as brine but is more expensive,” he said.

When winter comes and roads start to ice, WYDOT relies mostly on brine, sometimes mixed with sand, Beers said.

Good for fish, bad for vehicles

While Wyoming fish seem safe, this could be bad news for vehicles.

Beers said vehicles rusting from brine aren’t nearly as bad as they used to be.

“Today’s vehicles are made very differently than vehicles in the 1950s, 60s and 70s,” he said.

That’s because most modern vehicles have rust-resistant undercarriage coatings.

Even so, the brine can still corrode exposed wiring on the underside of vehicles or trailers, and at least some risk of rusting remains, Beers said.

“I still tell people to wash their vehicles after a big storm,” he said.

***For all things Wyoming, sign up for our daily newsletter***

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button