Water from rain or melting snow either seeps into the ground or “runs off” to lower areas, making its way into 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 wastes, sediments, oils, salts, trace metals, grass clippings, leaves and litter. Stormwater polluted runoff can be generated anywhere people use or alter the land, such as farms, yards, roofs, driveways, construction sites, and roadways.