ABSTRACT
Availability of freshwater has determined the growth of civilizations in the past. As the world’s population continues to increase, it is predicted that the availability of freshwater for human needs could be a serious limiting factor in the future. Though the 24estimated total volume of water on the planet is about 1.4 billion km3, nearly 96.5% of it is held up in the oceans as saltwater. An estimated 10.5 million km3 of freshwater, which is about a third of the total freshwater available, are stored below the surface of the Earth in the form of groundwater. It is widely, but unevenly distributed and is an important source for irrigation and drinking purposes. Groundwater exists whenever water infiltrates beneath the surface, the soils and rocks beneath the surface are porous and permeable enough to hold and transmit this water, and the rate of infiltration is sufficient that these rocks are saturated to an appropriate thickness. Groundwater is a renewable resource and therefore, if located, exploited, and managed carefully, can sustain forever.
