Science 101: Boreholes, more good water for drinking

Thulani Shabangu is a BSc graduate keen on sharing his passion for science with the youth of Vryheid.

IN areas like Vryheid where the rain has become scarce, groundwater is an emerging alternative resource for potable water. In this article we will focus on the quality of groundwater. The question we want to answer is if groundwater is bad for our health?

Let us start by defining some terms that you will encounter in this article.

Borehole

A shaft sunk into the ground to access ground water

Groundwater

In layman’s terms it’s the water found underground. Groundwater did not originate underground, it’s the water that was once surface water or rainwater which, through infiltration, gets through the soil and some rock particles and find its way underground. It’s also found in cracks in rock. Even though groundwater is actually cleaner than surface water, it’s not always perfectly clean.

Infiltration

This is the process by which rain enters the soil.

Surface water

This is the water found in dams, rivers, lakes and other sources on the earth surface. Climate change comes with droughts and disturbs rain patterns which decrease the amount of surface water.

Reduced rainfall

We still have rain but it doesn’t rain as it used to in summer. About 9% of the total South African water supply is from groundwater and about 77% is from surface water. The remainder is from recycled water.

What are contaminants found underground?

If the environment at which the borehole is constructed is clean, ground water from that borehole doesn’t require any treatment. If the borehole is drilled in an area close to industries, burial sites or any other pollution source; there is high risk of encountering groundwater pollution. In rural areas there are poor sanitation practices such as undisposed human faeces and urine. Microbes from this waste infiltrates into the ground which can contaminate groundwater.

As infiltration occurs, many of these contaminants mix with water and sink underground. The soil particles filter the large particles of dirt (faeces, chemicals, minerals, bad organisms etc.). Some dirt dissolves in water and are in small sizes that soil cannot filter. The pollutants are small in size and cannot be seen by the naked eye. Only chemical tests can detect the contaminants and only microscopes can detect the harmful microorganisms and bacteria in water.

Sicknesses associated with groundwater pollution

The different chemicals, poisonous substances and bacteria in the ground may cause a wide range of diseases. Some of the diseases associated with water contamination are cholera, typhoid and dysentery, diarrhea, teeth problems, bone problems and more.

Summary

If you have enough money to drill your own borehole;

– Get a professional geohydrologist to check for the best drilling site.

– Ensure there are no water pipes, waste pipes and power cables under the targeted area.

– Select an area away from pollution (waste, dry toilets, kraal, burial sites, industrial waste etc.)

– Contact a reputable driller with good equipment

– Use high quality materials to construct your borehole.

– Do not try to service your own borehole, contact an accredited professional in borehole maintenance.

– Test your water regularly for possible contamination. This must be done by a specialist.

To know if a contractor has the required expertise, ask them the following;

– Ask for referrals, speak to his/her previous clients about his services.

– Ask if the contractor has health and safety procedures.

– Check if the contractor works to a recognised standard.

– Let them provide you with a guarantee

Of course there are many more factors to consider when drilling your own borehole, here we are only scratching the surface.

If the municipality takes responsibility for constructing the community borehole;

– Keep the borehole area well protected.

– Remove or report all the waste in a borehole area.

– Use borehole water responsibly.

– Report issues related to the borehole to the municipal offices.

If you become sick and you suspect it’s because of the water you have consumed, go to the clinic or see the doctor. If they think it’s because of the contamination, report to the municipality so they can clean and disinfect the borehole.

– Do not pollute the borehole area

Some come to do their laundry at a borehole area. The dirty and soapy water which is spilled on the ground infiltrates the ground. The chemicals in soap may contaminate the borehole water if the borehole is not properly sealed on the surface. The contamination process may take time depending on the amount of dirty water spilled and the height of a borehole but it’s safer to avoid this act.

YOU MAY ALSO WANT TO READ: Science 101: Is your tank water clean? How clean is your clean?

  AUTHOR
Issued by Thulani Shabangu and edited and reviewed by Prof JJ Simonis and Prof A Basson

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