SA’s Hidden Treasure - Groundwater and its use

South Africa’s water crisis is well-documented, with surface water resources under immense pressure from overuse, pollution and climate change. There is another critical water source that often goes unnoticed, however: groundwater. This underground reservoir, accessed through boreholes and springs, serves as a vital backup to the country's primary water supply and is increasingly becoming a lifeline, especially for rural communities and agricultural operations.

Despite its depth and presumed natural protection, groundwater is not immune to contamination, says Charlotte Metcalf, CEO of the South African National Bottled Water Association (SANBWA): "One might think that groundwater is naturally protected, seeing as it resides deep underground. But the influence of human activities is not sparing these underground reservoirs.”

GCS Water and Environment CEO Andrew Johnstone agrees: “Because groundwater is an invisible resource, management is more difficult. Where groundwater is located close to human activities it may become contaminated by anthropogenic sources such as sewerage leaks and chemicals (for example pesticides used in neighbouring gardens), making it unfit for human consumption.” A 2021 study published in ScienceDirect titled "Groundwater Contamination in Sub-Saharan Africa" revealed alarming levels of harmful bacteria, such as E.coli, in groundwater sources close to human activity.

Households and business premises that utilise boreholes for drinking water must be vigilant; it is crucial for borehole users to not assume the safety of their water, especially if they are near human and/or industrial activities. Regular testing and monitoring of borehole water are essential practices to ensure it remains safe for consumption.

Groundwater supplies the majority of small urban and rural communities in South Africa and is critical in agriculture where it is used for livestock and irrigation – the vast majority of famers in Southern Africa rely on groundwater for both domestic consumption and livestock watering. Drilling a borehole seems to be a solution during times of water crisis when taps are dry, but any borehole that is drilled must take into account nearby sources of contamination - septic tanks, cattle kraals, cemeteries – this list is long.

Protecting this precious resource is paramount, and the bottled water industry, particularly SANBWA members, are leading the way with stringent requirements for source protection: "The source and borehole are the very foundation of the business. It is critical to start off with a correctly drilled borehole, the correctly installed pump and the source protected from subsequent contamination, whether accidental or deliberate.”

SANBWA stands out with its advanced hydrogeological study requirements, ensuring that the abstraction of groundwater is done responsibly and sustainably. Their guidelines stipulate that water from subterranean sources should be bottled in its natural state, free from any contact with air or contaminants. This includes a proper borehole sanitary seal to prevent contamination from surface water, animals and insects. SANBWA requires all members to commission a proper hydrogenolytic report prepared by a professional hydrogeologist and reviewed by a second hydrogeologist. In this report the hydrogeologist must identify any and all potential sources of groundwater contamination and comment on the potential impact on the aquifer.

Environmental conservation is integral to SANBWA’s philosophy, drawing from historical practices in Europe where bottlers have protected catchment areas since the 19th century. Metcalf highlights that SANBWA members engage in comprehensive protection efforts, including limiting human activity, banning pesticides and promoting sustainable agricultural practices around recharge areas - education regarding the protection of groundwater is the most important method of protecting groundwater, followed by legislation.

"A source vulnerability assessment must be performed for the recharge area or zone of influence of the source," she adds, underscoring the meticulous approach required to safeguard groundwater.

South Africa’s reliance on groundwater is growing, paralleling global trends where nearly half of the world's population and three-quarters of its irrigation needs depend on this invisible resource. Due to climate change and human impact, surface water resources have become increasingly variable and the importance of maintaining clean and sustainable groundwater sources cannot be overstated - it is a strategic imperative for South Africa’s water security.