Water runoff from land into rivers, streams, lakes or other bodies of water can be a source of water pollution. Because it does not originate from a defined point, this type of pollution is called nonpoint source pollution. Nonpoint source pollution is caused by rainfall or snowmelt moving over and through the ground. As runoff moves, it picks up and carries away natural and human-made pollutants, eventually depositing them into bodies of water.

Nonpoint source pollution can include excess fertilizers and pesticides from agricultural and residential areas; oil and chemicals from urban areas; sediment from eroding areas; and bacteria and nutrients from livestock.

States report that nonpoint source pollution is the leading cause of water quality problems. EPA provides tools and guidance to states, communities and individuals to help prevent and control nonpoint source runoff pollution.

To learn more about nonpoint source runoff pollution and what you can do to control it, visit the links below.