Pub. date: 2011 | Online Pub. Date: May 04, 2010 | DOI: 10.4135/9781412973816 | Print ISBN: 9781412996822 | Online ISBN: 9781412973816 | Publisher:SAGE Publications, Inc.About this encyclopedia
Nonpoint Source Pollution
Matthew R. Opdyke
Nonpoint source pollution is the introduction of impurities into a surface-water body or groundwater from dispersed origins (e.g., fertilizer runoff from lawns) compared with point source pollution, which originates from a definitive location (e.g., wastewater treatment facility). Most nonpoint source inputs fall into six major categories: sediments, nutrients, road salts, heavy metals, toxic chemicals, and pathogens. The primary pollutant for any given city is largely determined by the location and development status of an urban area. For example, Atlanta, Georgia, receives less snowfall than cities in the northeastern United States, thus, road salts will be a minor pollutant in Atlanta compared with heavy metals and toxic chemicals. In addition, heavy metals and toxic chemicals from road and parking lot runoff will be more prevalent in downtown Atlanta compared with Atlanta's sprawling suburbs, where increased construction activity may cause sediments to be the primary nonpoint source pollutant. In urban regions, nonpoint ...