The significance of groundwater.

Human beings cannot survive without freshwater. Besides rain, and glacial charged surface water sources such as lakes and rivers, groundwater provides another vital source of freshwater. Yet, groundwater reservoirs are being depleted and polluted at an alarming rate - an issue that merits much closer attention.

A recent UN report 'Groundwater: Making the invisible visible' highlights issues of relevance to this vital natural resource. For eg, it points out how nearly 30% of all freshwater on Earth is stored underground. Groundwater provides nearly half the water used for domestic purposes, and it is an especially important resource for rural populations not connected to public or private water-supply systems.

Groundwater is not just important for humans. Water holes in dry areas are usually fed by groundwater, which helps maintain complex ecosystems. Wetlands, and other water bodies, are often also dependent on groundwater as one source of replenishment.

Despite the importance of groundwater, underground aquifers which have taken millennia to form are being rapidly depleted, at rates which far exceed their capacity to recharge. While it is difficult to quantify the overall amount of groundwater stored in underground aquifers, NASA calculations back in 2015 had indicated that more than half of our planet's 37 largest aquifers were under immense stress.

Besides excessive extraction, groundwater pollution is another major problem. Industries use groundwater for manufacturing, mining, construction and oil and gas extraction. The apparel, food and beverage sectors are also heavily dependent on groundwater for their production processes. Such industries not only use up a lot of water, but also pollute groundwater sources via discharge of untreated or partly treated industrial effluents.

Agricultural production is another culprit regarding groundwater extraction and pollution. The rampant use of chemicals in agriculture contaminates groundwater making it unfit for drinking. Moreover, immense amount of groundwater is used up for irrigation as well as livestock farming and its associated activities, such as food processing.

Groundwater aquifers are significantly stressed within populous South Asia. India now uses more groundwater than China or the US...