SR-2/2000-2001 : Non point source pollution state of the art

Abstract

Non-point source (NPS) pollution originates from diffuse land areas that contribute pollutants to surface and ground water bodies. Sediments, nutrients and pesticides can enter surface water bodies through runoff, and nutrients and pesticides can enter ground water through leaching. Modem agriculture has 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 ground water resources. Chemicals (fertilizers and pesticides) applied in agro-ecosystems invariably enter the hydrological cycle, causing contamination of surface water and ground water resources. Nutrients and pesticides, particularly, are of major concern because of eutrophication and toxicity problems. Nutrients and pesticides are transported from cropland either by being adsorbed 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 the river system. In this report a review on several aspects of NPS pollution, including effects and extent of pollution in surface and ground water bodies, pollution control measures, monitoring and modelling, and management options is presented.