Skip to main content

Nonpoint Source

Nonpoint source

A diffuse, scattered source of pollution . Nonpoint sources have no fixed location where they discharge pollutants into the air or water as do chimneys, outfall pipes, or other point sources. Nonpoint sources include runoff from agricultural fields, feedlots , lawns, golf courses , construction sites, streets, and parking lots, as well as emissions from quarrying operations, forest fires, and the evaporation of volatile substances from small businesses such as dry cleaners. Unlike pollutants discharged by point sources, nonpoint pollution is difficult to monitor, regulate, and control. Also, it frequently occurs episodically rather than predictably. Where treatment plants have been installed to control discharge from point sources, nonpoint sources can be responsible for most of the pollution found in bodies of water. As much as 90% of the pollution load in a body of water may come from nonpoint sources.

See also Water pollution

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Nonpoint Source." Environmental Encyclopedia. . 16 Feb. 2019 <>.

"Nonpoint Source." Environmental Encyclopedia. . (February 16, 2019).

"Nonpoint Source." Environmental Encyclopedia. . Retrieved February 16, 2019 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.