Unless you live on a farm or have faced an extreme drought, odds are that you have not spent any time thinking about groundwater – the theme of this year’s World Water Day on 22 March.

Dr Lize Barclay Senior Lecturer in Futures Studies and Systems Thinking at the Stellenbosch University Business School says since groundwater is invisible and deep underground, we only tend to consider it during times of need.

“Only about 0.3% of the world’s freshwater is found in the surface water of rivers, lakes, swamps, wetlands and the atmosphere. About 31% is found in groundwater, originating from rain or melting snow that permeates through the ground to settle in aquifers, feeding springs and other surface water sources, or become accessible via wells and pumps. The rest of our water is found in ice sheets and glaciers – hardly accessible.”

Dr Barclay says the arid areas of the world are almost entirely dependent on groundwater for survival yet “ with climate change and changing weather patterns, and droughts becoming progressively prevalent and severe, we will increasingly turn to groundwater as a solution.”

“Most concerning is the overuse and overexploitation of groundwater, where it is used faster than it is being replenished. This could potentially lead to not only a lack of fresh water for future generations, but also for subsidence and instability of the land, especially where the groundwater has been withdrawn from areas with certain kinds of rocks, such as fine-grained sediments where the water is in part responsible for holding the ground up. In coastal zones, depletion or even just excessive extraction of groundwater could lead to the inflow of seawater, called saltwater intrusion, thus contaminating the water supply.”

In addition, she warns that plastic waste is raging havoc in our oceans: from straws getting stuck in the noses of turtles to plastic bags being confused for jellyfish.

“The Great Pacific Garbage Patch is an accumulation of plastic waste which is an estimation of 1.6 million square kilometres, possibly containing an alarming 1.8 trillion plastic pieces with a weight of at least 79 tons.”

Apart from the very visible plastic pollution in the ocean, Dr Barclay says,  microplastics are the unseen menace, which is potentially harmful to ecosystems and humans alike.

“Even the Great Pacific Garbage Patch which contains visible plastic waste, is 94% made up of microplastics. Microplastics are plastic pieces that are smaller than 5 millimetres across. It results from larger plastics that have broken down in time, and from microplastics that have been added to medicines, nappies, pesticides, paints, detergents and cosmetics; as well as the washing of clothes that contain acrylic, nylon, spandex and polyester fibres. Cosmetics companies have added microbeads to facial scrubs, which is now adding to microplastic pollution in water.”

Dr Barclay says it’s not only in oceans or on land where plastic is a problem.

“It is estimated that terrestrial microplastic pollution could be 23 times higher than marine micropastic pollution.  Less than 10% of plastic is recycled, with the majority ending up in landfills. It could take up to a thousand years to decompose and in the meantime, it leaches toxic substances and microplastics into the soil.”

“One-third of all plastic waste ends up in soils or freshwater. The toxins and micro-plastics eventually end up in our groundwater. It is especially chlorinated plastic that could release harmful chemicals into the groundwater and surrounding ecosystem. With the use of groundwater for irrigation and water supplies, the harmful effects of microplastics and nanoplastics then end up in our drinking water and food.”

Studies on the harm of microplastics indicate that microplastics could disrupt hormones and also facilitate the increased transference of contaminants along the food chain.

“Microplastics themselves break down further into nanoparticles which then have been found to enter the food chain, cross the blood-brain barrier or even the placenta. When they are within cells, they could trigger alterations in biochemical reactions and gene expression. Their surfaces are also used by other harmful chemicals to hitchhike a ride upon through the food chain up to humans. Bioaccumulation of toxins also takes place in groundwater, due to the accumulation of microplastics and their hitchhiking chemicals within stationary water.”

A study has found microplastics in 93% of all bottled water and hosts the highest number of microplastic particles of the substances tested. Thus, one is drinking plastics within a plastic bottle, even if the water comes from a spring and thus groundwater.

“We are not saying you should rather drink beer than water, but on World Water Day 2022 it is not only the invisible groundwater that we have to contemplate but also the invisible microplastics that are accumulating in the groundwater.”

“As consumers, we have to embrace the zero waste movement and limit our use of single-use plastic or products that contain microplastics. The role of businesses is to embrace circular design and find alternatives to plastics and microplastics in their products. If we amend our ways, we might just ensure a sustainable and equitable future for all.”

World Water Day has been observed since 1993 to raise awareness of the importance of the preservation of water, as well as the 2.2 billion people in the world that do not have access to safe drinking water. The day furthermore advocates for the need for the sustainable management of freshwater resource which aligns with the Sustainable Development Goal 6: Ensure availability and sustainable management of water and sanitation for all by 2030.