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Nonpoint Sources

Ground Water Hydrology

  1. Chakresh K. Jain

Published Online: 15 APR 2005

DOI: 10.1002/047147844X.gw781

Water Encyclopedia

Water Encyclopedia

How to Cite

Jain, C. K. 2005. Nonpoint Sources. Water Encyclopedia. 5:331–337.

Author Information

  1. National Institute of Hydrology, Roorkee, India

Publication History

  1. Published Online: 15 APR 2005


In recent years, it is being recognized that the nonpoint sources of water pollution have greater importance than point sources. This is due in part to the continuing efforts to reduce pollution from point sources during the past few decades, as well as recognition that nonpoint sources, such as storm water, may contain harmful contaminants. Modern agriculture has also relied, among other things, on heavy use of fertilizers and pesticides. This has largely occurred without any serious regard to the environmental consequences, especially pollution of both surface and groundwater resources. Chemicals (fertilizers and pesticides) applied in agroecosystems invariably enter the hydrologic cycle and contaminate both surface and groundwater resources. Nutrients and pesticides, particularly, are of major concern because of eutrophication and toxicity. Nutrients and pesticides are transported from cropland either by being absorbed onto eroded soil particles or dissolved in runoff water. This has increased the need to identify and quantify major sources of nutrients and pesticides deposited within river systems. In this article, some basic concepts of nonpoint source pollution, including the effects and extent of pollution in surface and groundwater bodies, pollution control measures, monitoring and modeling approaches, and management options are presented.


  • nonpoint source;
  • groundwater;
  • surface water;
  • nutrients;
  • pesticides;
  • pollution control