While this article and video focuses on Washington’s Puget Sound the situation is similar here in Canada.
It begins when diver, Laura James, comes across a big black column of black on one particular dive that was billowing non-stop. She found the source: stormwater.
Stormwater is a chemical cocktail of sediment, grease, pesticides, fertilizers, heavy metals and everything else that washes from the surface. While many believe stormwater is treated, many times this is not the case.
A project at Washington State University is studying how runoff affects aquatic animals. They collected stormwater and filtered half of the water through soil columns meant to imitate rain gardens. They then put the straight stormwater in aquariums and the filtered stormwater in different aquariums, and gave each aquarium 10 juvenile Coho salmon and waited to see what would happen.
Within 12 hours all of the fish in the straight stormwater had died whereas all the fish in the filtered stormwater survived. The functionality of rain gardens certainly looks promising but this team at Washington State University is working to find out what the best plants to use are, what the best soil mixture is, the lifespan of these gardens and more.
In the meantime, there are actions we can all take to help reduce the toxicity of stormwater or urban runoff. Check out our Water Challenge to see what you can do!