Stormwater: Oh, the Places You’ll Go!

Did you know stormwater does not go to a wastewater treatment facility? Pollutants that go down the storm drain on the streets where you live, such as salt, grass clippings, leaves, pet waste, fertilizers, pesticides, and residue from automobiles, are funneled untreated to the nearest waterbody.

Water that goes down the stormwater drain on the street outside your home is funneled to the nearest waterbody. That could be the pond in your backyard, the lake down the road, or even the Mississippi River.

Those waterbodies can include our local lakes, streams, wetlands, natural and manmade ponds, and rivers—such as the Mississippi. In metro areas, the pond behind your house or the lake down the road most likely receives stormwater runoff.

Just one teaspoon of salt permanently pollutes five gallons of water. Eyeball the image above and it’s easy to conclude how a season’s worth of cumulative municipal road salting adds to the contamination of our waterways.

An ever-increasing environmental stressor to our local waters is salt (de-icer).  Melting ice and snow runs off our roofs, sidewalks, and driveways and flows to and down our stormdrains.  Any salt picked up on this journey makes its way into our local waterbodies. While salt dissolves in water, it does not break down. It remains a permanent pollutant that accumulates over time. The only known method of removing salt from water is through costly reverse osmosis, which isn’t an option for cleaning up our waterbodies.

Used over the course of a winter, the contents of a 50-pound bag of salt will permanently pollute 10,000 gallons of water.

Salt concentrations in the Mississippi have increased 81% since 1985.


You can help make an important impact in reducing local water pollution. Sweeping up excess salt and throwing it away (or saving for future use on sidewalks and driveways) helps keep destructive salt out of our waterways. And, by keeping your driveway, street curb, and storm drain swept and clear of pollutants year-round (grass clippings and leaves are also water pollutants as they contain phosphorus which fuels oxygen-depleting algae), you are helping prevent water pollution in your own neighborhood.

Your street is a local tributary that connects to our local waterbodies. Salt, fertilizer, grass clippings, leaves, and pet waste that go down our stormdrains are a large source of pollution in our lakes, streams, rivers, and ponds. Keep the drain by your house clean year-round.
As they say, “Only rain down the drain.”
Be sure to sign up for The Butterfly Effect journal to learn how to green your neighborhood year-round.
Photo credits for stormdrain and water images: Minnesota Pollution Control Agency