Rainfall
As rainfall lands on the surface of the ground, two things happen, either the water soaks into the ground, or it runs off the surface, flowing down hill along with the other runoff. As stormwater runoff flows toward our rivers and streams, it encounters different surfaces and materials, and sometime picks up substances and takes it along for the ride. This is how stormwater pollution occurs, and the following information is presented so that you may understand how stormwater gets polluted, and how you can help prevent this.