Nonpoint source

A contributing factor to water pollution that cannot be traced to a specific spot. Man-made or man-induced alteration of the chemical, physical, biological, or radiological integrity of water, originating from any source other than a point source. Pollution which comes from diffuse sources such as urban and agricultural runoff. Major nonpoint sources of pollution include excess farm and lawn nutrients that move through the soil into the ground water or enter local water directly through runoff during heavy rains; uncontrolled storm water runoff from construction sites; forestry operations; animal wastes; and even pollutants released directly into the atmosphere. Pollution sources which 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 stormwater runoff. The commonly used categories for nonpoint sources are: agriculture, forestry, urban, mining, construction, dams and channels, land disposal, and saltwater intrusion.