As rising temperatures and droughts dry up rivers and melt mountain glaciers, people are increasingly dependent on the water beneath their feet. Yes, ground water that people in some parts of the world use to wash clothes, drink and so on. The problem is, how long can this last?
Groundwater resources currently supply drinking water to nearly half the world's population and about 40% of the water is used for irrigation globally. Most of the water stored underground has been there for decades, and much of it has been stored for hundreds, thousands, or even millions of years. Older groundwater tends to be deep underground, where it is less susceptible to surface conditions such as drought and pollution.
As shallower wells dry up under the pressure of urban development, population growth, and climate change, old groundwater becomes increasingly important.
Is there a taste difference?
Of course there is a difference in taste when drinking wine that is 40 years old compared to wine that is only 5 years old. So is water. Water that had been underground for a thousand years could also taste different. This water releases natural chemicals from the surrounding rock thereby changing its mineral content.
Some of the natural contaminants associated with groundwater age - such as mood-boosting lithium - can have a positive effect. Other contaminants, such as iron and manganese, can be irritating.
Older groundwater is also sometimes too salty to drink if taken without expensive treatment. This problem is commonly experienced by people who live near the coast, as launched by Science Alert, Monday (11/10/2021). Over-pumping creates spaces that can draw seawater into the aquifer and contaminate drinking water supplies.
It should be noted that 'primitive' groundwater took thousands of years to naturally replenish. When a drought occurs, the natural underground storage space is compressed when empty, so it cannot be refilled to its previous capacity. This compaction in turn causes the soil above to crack, warp and sink.
However, people are currently drilling deeper wells as drought drains surface water and agriculture is more dependent on groundwater.
How long will groundwater be sufficient for life?
Groundwater may be resistant to heat waves and climate change, but if humans use them greedily without calculating, humans will be faced with problems, one of which is land subsidence.
So far, the answer to drought has been to drill the soil deeper, again and again. However, this answer cannot be used in real terms because the concern about the impact could far outweigh the 'benefits'.
The answer to how groundwater can survive is how we can use this water in the right way. With wrong management, groundwater extraction methods become unjustified. Given that it takes thousands of years to replenish 'old' water into the deepest layers of soil, regulations are needed that are in synergy with expert opinion to keep humans alive using groundwater.
Efforts to save water use must also be familiarized from an early age. Remember, for our grandchildren later
