The good, the bad, and the borehole

More than 26 000 boreholes have been registered with the City of Cape Town to date. This is up from 1 500 registered boreholes and well points in January 2016.

Cape Town Councillor Xanthea Limberg says caution should be exercised when interpreting this data. “It is highly possible that significant numbers of residents made use of unregistered boreholes before restrictions were passed, and only took steps to register the boreholes due to increased awareness and enforcement,” she explains.

Whichever way you look at it, there has been a massive increase in the number of people drilling boreholes to use underground water. Drill rigs are now a familiar sight in wealthier neighbourhoods where individual domestic users can afford to drill down into aquifers to supplement their 50litre a day water allowance.

Drill rigs are now a common sight in Cape Town suburbs.

Drilling companies do not need licenses to drill boreholes, however, if they are drilling on behalf of a client they must register the borehole with the City. Previously there were said to be a handful of established companies in Cape Town drilling boreholes.

“The main reputable drilling companies operating in the Western Cape area prior to the drought crisis were SA Rock Drills, RPM Drilling, USA Drilling, Drillco, Gerritsen Drilling, MEK/JR Drilling and RoundOne Drilling. Fairbrother also do drilling, but are more involved in geotechnical work,” says associate and principal geologist at Umvoto Africa, Dylan Blake.

With the increased demand for boreholes across the Western Cape, and because its takes two to three days to drill a borehole, some of these companies now have waiting lists of up to a year. Blake adds that when demand outstrips supply, costs increase, making it viable for drilling companies outside of the Western Cape to move rigs, plant and drilling teams to the Western Cape and set up base. “Some of the reputable drilling companies that have moved into the Western Cape in the past year and a half include EDRS (Johannesburg), Master Drilling (Johannesburg), Steyns Drilling (Port Elizabeth), J&M Drilling (Johannesburg) and Vula Amanzi (East London).”

“Along with the reputable drillers however, has come probably twice as many disreputable fly-by-night drilling companies, both local and outside of the Western Cape in origin,” says Blake. The problem with inexperienced ‘fly-by-night’ drilling companies (both local and from outside of Cape Town) is that they often do not understand local geology or hydrogeology, which can cause problems during drilling. “Although initially seeming cheaper, they usually cost more in the end than most reputable drillers, because as a result of their inexperience with respect to the underlying geological conditions they either have to re-drill one or more times, or they construct the borehole poorly and use more materials than required, or use the incorrect materials,” he explains.

The long-term problem with so many new boreholes being drilled on private properties is that there is no control over the water that individuals are using. Under the level 6B water restrictions in Cape Town, the use of borehole water for outdoor purposes such as watering a garden or topping up a swimming pool is “discouraged”, and users are expected to comply with national regulations and have metering records available for inspection. Whether or not this is being done is more difficult to tell.

There is also no requirement for a license to have or use a borehole. Dr. Kevin Winter from the UCT Future Water Institute explains: “The Act says that the general provision for a license is not required for someone using less that 10 000litres/day. That’s a huge load of water. So schedule 1 simply says, go ahead, use the water, but we have very little control over how that water is being used. The fact is that the water is being used without any monitoring taking place.”

Limberg says that while the City of Cape Town registers boreholes, this is only to ensure that they don’t interfere with exiting City infrastructure. “Monitoring and licensing of the extraction of groundwater is a National Government competency, and any questions surrounding the sustainability of the resource should be directed to the *National Department of Water and Sanitation.”

However, with the reported mismanagement at the national department, the City of Cape Town may have to consider monitoring the resource itself, particularly if it wishes to ensure the sustainability of its groundwater extraction programme. Ultimately 80 million litres a day of underground water is expected to be used to augment the City’s water supplies. This will come from the Atlantis aquifer, the Cape Flats aquifer and the Table Mountain Group aquifer.

Immediate environmental concerns

As well as the serious long-term implications of so much unmonitored groundwater extraction, there are immediate impacts of borehole drilling that can cause damage such as water pollution and subsidence, which often has associated infrastructural damage.

Dr. Winter notes that earlier in 2018 there were incidences of fine clay being deposited into the Liesbeek river, which runs through the southern suburbs of Cape Town. “Its a pollutant. What happens is, when the drilling takes place there is no circulating of that water, it gets discharged into the storm water and it finds its way into the rivers. And the Liesbeek river has certainly been a victim.”

There have also been incidences of underground subsidence during drilling, which has resulted in cracked pavements and damage to nearby property.

In the city bowl suburb of Vredehoek, walls cracked across the road from the home where a borehole was being drilled. An affected resident confirmed that insurance claims for the structural damage suffered to the homes were rejected by the homeowners’ insurer, which said that the drilling company was liable.

When contacted however, the owner of the Port Shepstone KwaZulu-Natal headquartered drilling company said that the terms and conditions of it’s contracts preclude it from responsibility for any damage that might occur. This is because they cannot ensure that the soil is hard enough or that the foundations of the home are strong enough before they start drilling. “Our business is to drill a borehole and we have years of drilling experience. A client invites us to drill, but we cannot take responsibility if the ground is soft or the foundation is not solid,” said Gyan Maharaj. However he could not confirm whether or not it was his company responsible for drilling at the property, despite being sent images of drilling equipment bearing his company name and logo at the property at the time of borehole drilling.

Because there are no regulatory bodies that control drilling in South Africa, Blake affirms that liability is therefore carried by the client. “And if any problems arise during drilling that the drilling contractor obviously caused through bad drilling practice but does not want to fix or resolve (and the client does not have subsidence insurance or anything to that effect), then the only legal option would be to go through the National Consumer Commission,” he says.

Blake adds that he has heard of a few instances of damage, and spoken to reputable drillers who have been called in to fix the problems caused by ‘fly-by-night’ drillers who, for example, use the wrong drilling technique in certain geological environments causing large volumes of subsurface material to be expelled at surface), as well as leaking artesian (water flowing out at surface) boreholes that are now impossible to contain at surface due to the borehole being drilled and cased incorrectly at depth.

What is monitored can be managed

Dr. Winter is concerned about the lack of monitoring of the underground water. “The long-term is very worrying because if we are unable to monitor effectively, we could damage the aquifer for years and years to come, so there is a real concern about that.”

He hopes to see “observation monitoring boreholes” established. These would be dedicated to understanding the water flows within the groundwater on a regional basis. In other words, there should be a number of boreholes dedicated to continuous monitoring, that can be done in high resolution.

This would mean that if issues such as excessive extraction take place, they could be dealt with. Rigorous monitoring would show if a particular neighbourhood was abstracting an excessive amount of water from the aquifer.

Replenishing the stores

Is there a risk that these precious underground water stores could be sucked dry? Hopefully not. Aquifers can be replenished. Dr. Winter shared an example where surface water is being used to replenish the underground water. Here, a small channel connecting the Liesbeek river to a floodplain beside it was excavated. This means when the water reaches peace levels it flows naturally into the floodplain, converting it into an active wetland, which helps to recharge the aquifer and reduces the flood risk downstream.

In response to questions from GroundUp readers, the City of Cape Town’s Ian Neilson said “It is not in the City’s mandate to regulate the usage of groundwater sources, but we have tried as far as possible to drive the message home that unlimited usage of boreholes will not be sustainable. The main consideration here is that private boreholes are not recharged. Private users do not replace the underground water that is used. This is in contrast to the City’s aquifer programme, where aquifer recharge will be a non-negotiable aspect of abstraction.”

It is reassuring to know that the City has a programme to replenish underground water, however the concern that domestic use is not being monitored is reinforced.

A recent artwork entitled “Borehole Straws” shown at a climate change adaptation conference in Cape Town sparked imagination in a way that few long-winded articles can. Artists Sonja Meyer, Kino Hogan and Jason Adams say that the artwork comments on “the uncontrolled extraction and use of groundwater as a long-term solution to the drought in Cape Town.” The plastic straw refers to a culture of negligent consuming, and the sculptures assume a standard range of borehole diameters so that audience members can relate as a small-scale consumer, to realise a collective contribution to the impacts of groundwater extraction.

“If more water is extracted than is recharged, aquifers could collapse, and land sinking may begin to occur in a matter of months years or decades. This has been seen to happen in areas of California following their recent severe droughts. On the coast, there is also a danger of seawater seeping into wellpoints when the groundwater level sinks below sea level. Groundwater has become an unavoidable measure for Cape Town’s water emergency, hence it is crucial to monitor groundwater levels and to control its use,” conclude the artists.

The artwork “Borehole Straws” shown at a climate change adaptation conference in Cape Town by artists Sonja Meyer, Kino Hogan and Jason Adams.

*The National Department of Water and Sanitation did not respond to questions sent by OSG.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s