How will snow melt will impact Maryland's waterways?
The snow is finally melting, but environmental experts say what's left behind could linger in local waterways for years.
As temperatures rise across Maryland, melting snow is washing road salt from streets and sidewalks into storm drains, and eventually into the Chesapeake Bay.
"All of that salt ends up going into the surrounding ecosystems," said Rebecca Hale, an ecologist with the Smithsonian Environmental Research Center.
What's the impact?
Road salt, which is mostly sodium chloride, dissolves into snowmelt and runs into nearby waterways. Hale said once that salt reaches tributaries like the Severn River, it increases the overall salinity of the water.
That can cause freshwater systems to become brackish, or even as salty as ocean water, which can be harmful to freshwater species.
"That salt is going to draw water out of their bodies and they're not going to be able to survive, or it can affect the way they eat and metabolize, their reproduction," Hale said. "So it can have lots of downstream impacts on those organisms."
Hale said the effects can build over time, causing long-term changes in rivers, streams and lakes.
"Where streams and rivers, lakes, are getting saltier and saltier and saltier, and that has a lot of important ecosystem impacts," she said.
Increases in chloride concentration
Hale said Smithsonian researchers have also seen major increases in chloride concentration in drinking water sources over the past few decades due to road salt runoff.
"It's not removed by our standard drinking water treatment processes," Hale said. "So you can remove it through processes like reverse osmosis, but that's really expensive and difficult and hard to do at scale. There's not a lot that we can do once it's in the water."
Hale said one way to reduce the impact is to use less salt in the first place and sweep it up before it gets washed away.
Researchers say people only need a handful of rock salt per square yard for de-icing, and by using only what's needed, residents can help reduce the amount of chloride that runs into local waterways.
