Groundwater is an extremely vital and critical resource on the planet that supports most people’s ever-increasing water requirements. Being more abundant than surface
water, its criticality to life sustenance and human well-being cannot be overemphasized. Groundwater caters to almost half of all the drinking water requirements worldwide; it supports forty per cent of irrigated agriculture and meets about one-third of the water supply required for the industry. It is the primary or overwhelming source of drinking water in many parts of the world and is often considered a dependable source of uncontaminated water. Despite its obvious importance, groundwater is an invisible resource, and in line with the famous adage “out of sight, out of mind”, groundwater all-over is mismanaged and highly abused. The groundwater level in several parts of the globe has plummeted rapidly during the past two decades due to intense competition among its users—agriculture, industry, domestic sectors—and an ensuing overdraft. The widespread pollution of surface water and its interconnectedness with groundwater, leachate from unscientific disposal of solid wastes, and untreated wastewater discharge has severely affected groundwater quality. Consequently, the world is in the throes of a severe water crisis.