Water from rain or melting snow either seeps into the ground or runs off to lower areas while making its way to streams, lakes and other water bodies. On its way, runoff water can pick up and carry many substances that pollute water. Examples of common pollutants include fertilizers, pesticides, pet waste, sediment, oil, salt, trace metals, grass clippings, leaves and litter. Polluted stormwater runoff can be generated anywhere people use or alter the land, such as farms, yards, roofs, driveways, construction sites and roadways.
https://cityofportlandtn.gov/394/Stormwater-Department