At a meeting with members of the Cape Town water department on 19th May 2022, it was noted that the Southern Suburbs has been experiencing a number of water supply pipe leaks, and this is expected to continue for years ahead as the old pipe is replaced.

The leaks and repairs result in disruption to the water supply, low water pressure, and the possibility of affected water quality. 

It was noted that some of the piping is made of asbestos cement.

Mention was also made of possible copper contamination.  A combination of acidic borehole water, the lack of proper pH adjustment, and no “RPZ” valve installed has led to corrosion of copper piping in some houses, and the water containing dissolved copper then pushing back into the municipal supply.

The municipality is doing a fantastic job attempting to rectify these problems, but they have a legacy of old, failing pipe to deal with, which will take years to replace.

There are three areas where EarthSmart Technologies can offer assistance to deal with the water supply infrastructure challenges we’re facing:

• Water quality improvement
• Water storage “buffer” tanks
• Pressure boosting pumps

Water Quality:

Disclaimer: We are in no way suggesting that the water supplied by the municipality is not up to standard, although the following points should be noted so that homeowners may make educated choices and be aware of precautionary options available to them.

Risk of Asbestos Contamination

Some of the old piping is asbestos cement, and broken asbestos pipes pose a potential health hazard. 

The asbestos cement piping has served well for decades but has now exceeded its design life. Aside from the water losses and inconvenience associated with the old pipes bursting, there is a risk of asbestos getting into the water during bursts and subsequent repairs. Asbestos use has been banned in South Africa since 2008.

Although there’s some contention over the potential health risk posed by ingesting asbestos fibres, there is concern that asbestos exposure through ingestion could be carcinogenic.

Copper Contamination

Copper is another potential contaminant in the water in our area. This has resulted from inadequate borehole filtration systems installed during the “Day Zero” water crisis. 

Aside from the blue/green stains on bathroom and kitchen fittings associated with copper in the water, copper can pose potential health risks.

Ingestion of too much copper can cause vomiting, diarrhea, stomach cramps, nausea, liver damage, and kidney disease. Infants (babies under one year old) are sensitive to copper and their bodies are not able to get rid of extra copper easily. 

Sediment

Residents have complained of their municipal water being “brown” after pipe repairs. As the pipe replacement in the area will take years to complete, this is expected to be an ongoing problem.

How do we treat these issues?

It’s not affordable for many households to purchase “whole-house” filtration systems, to treat all the shower, washing machine, and other household water.

Standard filters like foam “micron” cartridges and carbon block filters will not remove the contaminants we’re dealing with.

Our suggestion is to install an under-counter ultrafiltration system to treat your drinking water. An “under-counter” ultrafiltration system won’t help with the stains on your bathroom fittings, but it will certainly improve the quality of the water you drink.

Ultrafiltration is a much finer filtration method than standard filter cartridges can offer. The pore size (which affects the size of the particles which can be filtered) on an ultrafilter system membrane is between 0.01 and 0.1 micron. Standard filter cartridges will only catch particles 10 to 100 times bigger, so they’re not nearly as effective as an ultrafilter.

• Ultrafiltration significantly reduces copper and asbestos contamination, bacteria, and many other contaminants from your drinking water.
• Ultrafiltration is a cost-effective option and unlike reverse osmosis, it doesn’t need its own power supply.
• Our ultrafiltration unit will produce around 2 litres of purified, safe, drinking water per minute.

The membrane unit and cartridges need to be replaced periodically (as with any filtration system). How often they need replacement will depend on the amount of water used and the quality of the incoming water.

In day-to-day use, the ultrafiltration membrane can be cleaned by flushing with a small amount of water for a few seconds, and the system has a valve included for that purpose.

• Unlike reverse osmosis, ultrafiltration does not waste water (apart from the water for occasional flushing).
• The system can be installed by the homeowner or a plumber. The system needs its own dedicated faucet which is mounted on the kitchen zinc.
• Ultrafiltration does not remove beneficial minerals from the water and is a perfect match for treating water from the municipal supply.

The basic system has three filter components – a 5-micron sediment filter to filter larger particles, a carbon block filter for chlorine removal (among other contaminants), and the ultrafilter membrane cartridge.

If water disinfection is a concern, the system can be used together with Quantum Disinfection™ which is a brand new product for disinfecting water without needing an electrical supply, and can simply be used as an additional filter after the ultrafiltration system.

Reverse osmosis is another option for treating the water quality problems we’re facing and it produces the purest filtered water available, but it has some drawbacks when compared to ultrafiltration:

• Some of the water is sent to waste in the reverse osmosis process (often around 50% on the smaller systems)
• It needs an electrical supply to provide water pressure. There are systems available which don’t need a pump and electrical supply, however one of the problems we have in the Cape Town southern suburbs is that there is often not enough pressure from the municipal supply as the municipality has reduced the pressure to avoid pipe bursts.
• Some people prefer to retain beneficial minerals like calcium and magnesium, and these are removed during reverse osmosis (but not by ultrafiltration). These can be added back to the water after reverse osmosis with a remineralising cartridge if desired. 
• An “under-counter” reverse osmosis system produces water slowly, and to make sure that the house has a supply of treated water readily available, they are supplied with a storage tank, which takes up valuable space in the kitchen cupboard.

The space needed is around 40 x 40 x 20cm, roughly the space of a school bag. For the RO system, the same space plus a similar size for the storage tank is needed.

EarthSmart can supply either an ultrafiltration or reverse osmosis system, but for the specific problems we have with the municipal supply in the southern suburbs, we recommend the ultrafiltration system.

A third option is a counter-top RO unit which requires no installation and can be moved easily – great for moving easily to where it’s needed, or for taking on holiday with you.

For the cost of a few bags of groceries or a couple of tanks of fuel, make sure that your family has safe, great-tasting water.

Water Supply Disruptions:

For water security and pressure boosting, EarthSmart can supply a variety of systems customised to your requirements.

A “buffer tank” and booster pump will provide your home with a consistent water supply during water outages such as pipe repairs, and give ample water pressure in the house for your shower.

Each home has different needs according to the number of people and size of the house, and these systems are sized accordingly.

Contact us for details on how we can assist, to make sure that you have a consistent supply of good water for your home.