ABSTRACT
Ground water is considered as one of the indispensable resources of human civilization owing to its immense uses. However, indiscriminate use of ground water led it to be exhaustible and polluted. The contamination in water bodies including ground water system as well, taken place through two sources, point source and non point source. It is quiet convenient to identify point sources of water contaminants but high uncertainty prevails to find out the non point sources. However, plethora of research over many years, agriculture runoff has been recognized as the potential process for ground water contamination. A significant quantity of chemical pollutants including synthetic fertilizers, pesticides, insecticides, humic substances find their entry into the ground water system due to agricultural runoff and led to different health issues and even turned fertile soil into non productive one. Recently urban sector has also been identified as one of the non point sources of ground water contamination. There are several pathways which are associated with runoff from urban area have been found. The different land use activities in urban area including construction, excavation activities, farmland drainage, soil erosion results into the infiltration of heavy metals like chromium, mercury, cadmium, metal complexes, acids, microorganisms etc into the ground water system. Moreover, unprecedented changes in the climatic variables and climatic vagaries have triggered the rate of soil erosion and runoff from agriculture and urban sectors. Hence, the level of ground water contamination would be in highly variable state. In this compendium we like to showcase the key mechanisms involved in ground water contamination from the nonpoint sources as well to exhibit the mobilization pattern of contaminants in ground water system leached from the surface runoff under anticipated climate change condition.
