There are many factors that effect the quality of our surface water:

Coal Tar Sealants

Coal tar is a black liquid sprayed and painted on parking lots, driveways and playgrounds, but not on major roadways. Coal tar is the main sealant choice in the East and Midwest, with 85 million tons of the sealcoat used annually in the U.S.  Results from a Baylor University and USGS study indicate that “living adjacent to a coal-tar-sealed pavement is associated with significant increases in estimated excess lifetime cancer risk, and that much of the increased risk occurs during early childhood.” Additionally, polycyclic aromatic hydrocarbons (PAHs), or sealant dust, can damage the health of aquatic organisms, and can contaminate our stormwater and sediments in urban lakes and detention basins.  Winnetka and South Barrington have banned the use of coal tar sealants. The Sierra Club is closing following HB5578, and Cool Cities will keep you updated on any progress.


According to the Midwest Pesticide Action Center, each year, an estimated 10 trillion gallons of untreated stormwater runs into local waterways, picking up the pesticides applied to outdoor areas, like farms,  parks and lawns along the way.  The U.S. Geological Survey’s report, Pesticides in the Nation’s Streams and Ground Water, 1992-2001, found pesticides in 96 percent of all fish, 100 percent of all surface waters, and 33 percent of major aquifers studied. DuPage County Stormwater Management provides a helpful video to reinforce this environmental message.

Rock Salt

Rock salt, commonly used for snow-fighting operations, contains sodium chloride. According to The Conservation Foundation, chloride negatively impacts aquatic communities, kills plants, fouls drinking water, and persists — once chlorides dissolve in water, chlorides stay in the water. Traditional methods to filter other pollutants out of water just don’t work on chlorides. Use rock salt as sparingly as possible, and re-use it, as demonstrated in DuPage County’s “Love Blue. Live Green.” video.