Definitions for "Non-point source"
Pollution that enters any waters of the state from any dispersed land-based or water-based activities, including but not limited to atmospheric deposition; surface water runoff from agricultural lands, urban areas or forest lands; subsurface or underground sources; or discharges from boats or marine vessels not otherwise regulated under the National Pollutant Discharge Elimination System program.
Pollution that does not originate from a definable point (e.g., soil or urban runoff).
Pollution that, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and manmade pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water. Loadings of pollutants from NPS enter waterbodies via sheet flow, rather than through a pipe, ditch or other conveyance (www.epa.gov).
Keywords:  emission
emission