| Rivers and lakes are becoming saltier while law and practice limit effective responses.
In a dim hangar outside of Traverse City, towering piles of white crystals cast a glow in the twilight. Salts like those stored at the Grand Traverse County Road Commission maintenance facility keep Michigan roads, parking lots, and sidewalks clear of ice in the winter, a prudent safety measure for motorists and pedestrians. The mobility benefits of salt for a car-centric society, though, have an undesirable environmental side effect that has built up over decades of use: extensive damage to ecosystems and infrastructure.
Chloride — the catch-all term for salts — does not discriminate. It hurts mayflies and freshwater mussels, taking out species at the base of the freshwater food chain. It acts as a chemical instigator, loosening metals and nutrients that are otherwise bound in sediment and freeing them to flow downstream, thus feeding toxic algae in troubled places like Lake Erie. As with sun on skin, excess salt accelerates infrastructure aging. The metals and concrete in bridges, roads, and cars deteriorate faster when exposed to salts. | 