Salt helps to keep Michigan’s roads clear in the winter. But it also eats away at the pavement and pollutes the lakes and streams it washes into. A bill that passed the state Senate calls for an experiment - swapping or at least supplementing road salt with sugar beet byproducts.
Western Michigan University biologist Kathryn Docherty says that could benefit the environment by cutting down on salt pollution, a persistent problem in Michigan freshwater ecosystems. But putting the leftovers of beets that have been processed for sugar on the roads could also cause new problems.
Docherty says salt washing off roads builds up in lakes. That ends up driving the growth of methane-producing bacteria. And methane is a powerful greenhouse gas.
“So it becomes this larger issue of, ‘Are we causing our freshwater lakes to become these sources of a greenhouse gas?’” she said.
Docherty added that northern Michigan is an excellent place to grow beets.
“So if this really does work it could be a really good connection between beet farmers in that area and the Department of Transportation, potentially,” she said.
But Docherty also said that treating roads with sugar beet byproducts could also fuel unwanted growth of sugar-loving microorganisms. And that could cause another kind of freshwater pollution.
“Understanding what will happen as a result of putting a pretty easy-to-digest compound onto roads is something that I think should be studied further,” she said.
The beet de-icer bill, which would create a pilot program, is in the state House Transportation Committee.