97% of the water on Earth is salt water and only three percent is fresh water; slightly over two-thirds of this is frozen in glaciers and polar ice caps. The remaining unfrozen fresh water is found mainly as groundwater, with only a small fraction present above the ground or in the air.
Fresh water is a renewable resource, yet the world's supply of groundwater is steadily decreasing, with depletion occurring most prominently in Asia, South America and North America, although it is still unclear how much natural renewal balances this usage, and whether ecosystems are threatened.
In the present scenario of Covid-19 pandemic, it is advised that people wash hands frequently with soap and water for at least 20 seconds. The hydrophobic tails of the free-floating soap molecules attempt to evade water; in the process, they wedge themselves into the lipid envelopes of certain microbes and viruses, prying them apart. That's an effective way to eliminate viral particles on your hands. This is one of the best possible ways to remove the novel coronavirus (SARS-CoV-2) and in turn, keep a check on the global disease outbreak.
A proper hand wash involves lathering soap and scrubbing hands on both sides for at least 20 seconds, according to the WHO guidelines. A running tap uses 6 litres of water per minute. A 30-40 second hand wash would use up to around four litres of water if the tap is on, or two litres with the tap closed, while scrubbing with soap. A family of five members would thus need 100 to 200 litres of water per day only to wash hands 10 times a day than 4-5 times as usual. But for the 2.2 billion people in the world who lack safe drinking water — mostly in low- and middle-income countries — that advice will be difficult to heed. One gallon contains roughly 3,785 ml, so that's 15,140 drips per gallon, which means our 1-second-dripping faucet wastes over 5 gallons of water per day and just less than 2,083 gallons per year. Frequently washing hands also may cause wastage of water.
So how to avoid water woes in the time of such pandemic? Sensor taps should be promoted for use to reduce wastage of water while washing hands. The earth will be overburdened with waste water leading to eutrophication because of frequent hand washing with soap and detergent which will be another challenge. Ground water may also be affected seriously. Metros and cities are also sanitised by water spray which is supposed to consume a large volume of fresh water. The Government and policy makers should take a note of this as a future environmental concern.
Different measures are to be taken like setting up a network of public hand-washing stations – something done in West Africa during the Ebola outbreak of 2014. By 2025, large urban and semi-urban areas will require new infrastructure to provide safe water and adequate sanitation.
(Dr. Manas Ranjan Senapati is Dean, Computer Application & Science of Biju Patnaik University of Technology, Odisha. He is presently working as Professor of Chemistry in Trident Academy of Technology, Bhubaneswar. Views expressed are personal.)