We all see the water flowing into our storm drains during a storm or snowmelt. What most residents don’t realize, is that the water flowing into our Municipal Separate Storm Sewer Systems (MS4’s) is arriving dirtier and in greater quantities than ever before.
The problem occurs when precipitation lands on an impervious surface such as a paved street, rooftop, or driveway. Instead of the water slowly soaking into the soil and becoming purified, the water flows over these impervious surfaces and picks up pollutants. Oil and grease from roadways, pesticides from lawns, sediment from construction sites, and litter are all picked up by the water and conveyed directly to a storm drain with the impurities in tow.