Ill-defined runoff that enters waterways.
Scattered, diffuse sources of pollutants such as runoff from farm fields, golf courses, construction sites, etc.
Pollution sources that are diffuse and do not have a single point of origin or are not introduced into a receiving stream from a specific outlet. The pollutants are generally carried off the land by storm water runoff. Sources of NPS pollution include runoff from agriculture, silviculture, urban development, mining, construction, dams and channels, inappropriate land disposal of waste, marinas, and saltwater intrusion.
Pollution entering the environment where the sources cannot be traced to a single, identifiable point. Examples include atmospheric deposition, erosion, and runoff from parking lots, farms and streets.
Diffuse runoff without a single point of origin that flows over the surface of the ground by stormwater and is then introduced to surface or ground waters. NPSs include atmospheric deposition and runoff or leaching from agricultural lands, urban areas, unvegetated lands, onsite sewage treatment and disposal systems, and construction sites.
Pollution in runoff and seepage from land areas. The major origins of nonpoint source pollution include agricultural runoff; pesticide and fertilizer use; feedlot runoff; urban runoff from streets, yards, and construction sites; leachate from septic systems; runoff from forestry and mining activities; highway de-icing chemicals; and dredging and drainage activities.
Diffuse pollution sources (i.e., without a single point of origin or not introduced into a receiving stream from a specific outlet). The pollutants are generally carried off the land by storm water. Common nonpoint sources are agriculture, forestry, urban, mining, construction, dams, channels, land disposal, saltwater intrusion, and city streets.