22 FEATURE
Boreholes: Clear water doesn’ t mean clean water
By
Megan O’ Connor, with technical input from Wesley Van Der Giessen( Biozone Manufacturing), Anton Barkhuizen( Bore Restore) and Kurt Vermaak( Halcyan Water Conditioners)
In this article, we discuss everything relating to borehole water quality – and the plumber’ s role surrounding this.
Clear borehole water contains essential minerals required by humans, livestock and agriculture but can still contain‘ badly behaved’ minerals, bacteria and contaminants that shorten the life of plumbing systems, damage equipment and pose a risk to human health if not correctly treated. As more South Africans turn to boreholes as an alternative water source, plumbers are responsible for ensuring that this water is properly tested, treated and integrated into buildings.
Throughout South Africa, municipal water supply has become somewhat unreliable due to various reasons, which has prompted many businesses and homeowners to opt for back-up water supply solutions, the most common of which is borehole supply. While the uses of borehole water are endless, the borehole water must first comply with SANS 241: Safe Drinking Water, especially if intended for consumption.
Borehole water quality – what can go wrong? Unlike treated municipal water, borehole water is drawn directly from underground aquifers, meaning its quality is influenced by local geology, surrounding land use and the condition of the borehole itself. Borehole water often contains naturally occurring and environmental contaminants.
Naturally occurring contaminants include elevated concentrations of:
• Calcium
• Magnesium
• Iron
• Manganese
• Dissolved salts( high salinity)
Environmental contaminants:
• Bacteria and biofilm caused by biofouling – Biofouling occurs when bacteria produce a protective slime( biofilm) inside the borehole and plumbing system
• Iron bacteria
• Sediment
• Seepage
Boreholes close to farming, industrial and informal settlement areas are most commonly affected by seepage over time. Boreholes in residential areas most commonly have elevated levels of iron, manganese, total hardness( calcium) and bacteria counts.
Over time, these factors can restrict water flow, reduce borehole yield, increase pump wear, and negatively affect water quality. Poor maintenance and inadequate disinfection also contribute significantly to declining borehole performance.
So, what should you do first?
The Golden Rule: Test the water You cannot know if the water complies to SANS 241 if you do not know what is in it. Furthermore, you must never assume that a borehole’ s water is safe because a nearby borehole’ s water is safe – every single borehole is different.
So, ALWAYS test the borehole water before connecting it to a building. The results of the water analysis will also determine what filtration and treatment processes are needed, because different issues require different treatments. Water treatment is not a one-size-fitsall solution – the different treatment technologies target different aspects of the water composition.
Wesley van der Giessen, managing director at Biozone Manufacturing emphasises this point:“ We often see UV and ozone disinfection systems which have been incorrectly sized and installed in a manner that renders the technology ineffective.”
So, what water treatment options are available?
Choosing the correct treatment There are many treatment options available for borehole water – both chemical-based and chemical-free. These include:
• Water softeners.
• Physical water conditioners.
• Iron and manganese removal systems.
• Reverse osmosis.
• UV disinfection.
• Ozone treatment.
• Chlorine dioxide treatment.
• Mechanical / acid descaling. NOTE: Some boreholes may require a combination of treatment options as the water may have multiple contaminants that need to be treated to bring it in line with SANS 241.
www. plumbingafrica. co. za @ plumbingonline @ plumbingonline @ PlumbingAfricaOnline October 2026 Volume 32 I Number 08