Drought is the new normal

Date:19 January 2016 Author: Lindsey Schutters Tags:, ,

The future of water supply in South Africa is a twisted tale of corporate, social and governmental responsibility, and drinking your own wee, writes Lindsey Schutters.

In 2009 the lush, green southern Cape was declared a disaster zone. The headlines proclaimed it the worst drought in one hundred and thirty years. Millions of Rands were ploughed into damming the Brede river, desalination plants and, as a temporary measure, trucking water from George. With gardens and agriculture being the biggest leeches on our water supply, it’s telling that this fate befell the famed Garden Route. Also more telling is the speed at which local government acted to alleviate the cost of trucking water from nearby towns, a harsh reality that has long faced Northern Cape towns. But yet, even with a water restriction sign up in my guesthouse bathroom, I still kept the shower running while lathering up with shower gel. It can’t be that bad, surely?

Water demand in Cape Town has reached capacity. The Department of Water and Sanitation estimates that the Berg River dam project has pushed back the crisis date to 2022, with the Table Mountain Group Aquifier, seawater desalination and augmenting of the Voelvlei dam earmarked as measures to deal with 2035’s worst case scenario 800 million m3/a consumption needs.

Up north is a similar story with the capital implementing severe water restriction in early October 2015 and Johannesburg following suit after an early spring heat wave. Move into the Free State and the picture doesn’t get any better because poor rainfall meant that in August government had to intervene by releasing water from the Limpopo Highlands Water Project to help refill the province’s dams.

Weather SA are predicting lower than usual rainfall for summer 2015-2016 due to a strong El Nino presence in southeast Africa. South Africa needs an intervention.

Standing in front of one such intervention at Sedgefield’s Myoli Beach doesn’t inspire confidence. This plant was the workhorse in the recovery period after the 2009 drought, processing up to its 1,5 million litre daily fresh water capacity at regular intervals. The inconvenient truth is that the plant isn’t currently working and might never come online.

Knysna Municipality Technical Services Superintendent Calvin Jafta doesn’t want to get involved in the politics though, he only wants to show off his baby. “When you walk in, just look in front of you. We’ve had to call in the fire department twice already because of pofadders,” explains the thoughtful middle-aged man.

Even though it isn’t currently in operation, Calvin Jafta is quite fond of working on the Sedgefield 1,5 million litre desalination plant.
Image credit: Lindsey Schutters

Inside the container is the first of two identical units which can produce 750 000 litres of fresh water per day. Water is pumped from ocean boreholes through the award-winning bag filter system to remove solid particles, then through banks of carbon filters and finally into the reverse osmosis membrane. It’s a standard set up, but each company has its patented technology, this particular system was designed by NuWater (Knysna and Mossel Bay plants are Veolia designs). From the RO filter the water is then pumped through a pH balancing system and into storage tanks, ready to be reticulated.

The pump room that sends the fresh water to the holding tanks.
Image credit: Lindsey Schutters

“When this plant was running, I could only run during off-peak times. It costed about R10-plus per kilolitre. That’s why Eskom didn’t want to give us power,” Jafta says of the energy needed to turn seawater into drinking water. “When the Eskom parameters were green, I was here running the plant through the night. After a three hour period you get up to check if everything is still working, if the valves open, because NuWater (the developers) can call in to change the sequences if you’re not alert. This is a very nice plant and I liked working on it.”

Jafta monitors the Sedgefield district water supply and is involved in every project affecting the area. The Karatara river weir, for instance was installed after he detected salt water flowing up stream. What happened was the municipality opened the Swartvlei mouth after fears of flooding, but the sea then pushed in around 20 km upstream. “That was the first time I saw it, but it happens regularly now. When it’s not raining then at high tide the water goes upstream and we get saline water. The weir is designed with mechanical gates (which act automatically) that open when the water flows down stream and close if the flow rate is higher upstream.”

Unit 1 of the two identical reverse osmosis semi-permeable membrane filters can produce 750 000 litres of fresh water per day, at around an 85 per cent yield. The membranes are designed for the site’s specific water quality and salinity.
Image credit: Lindsey Schutters

The award-winning project was designed by Tuiniqua consulting engineers and incorporates a fish ladder to help the natural inhabitants overcome the man-made structure. This intervention also traps enough water to sustain Sedgefield for 10 days if drought conditions hit the area again, this should be sufficient time for the municipality to mobilise other emergency measures.

Peak summer periods the region is flooded with over 14 000 holiday makers, more than doubling the population. And many of those people own homes in the area and sit on the Wilderness and Lakes Environmental Action Forum, which is another headache for Jafta. “I’m working here in Sedgefield for almost 13 years, mostly in the water environment. I see over the years what’s happening and then the engineers come here because they have places and they’ve all got their own opinions and say ‘It should work and it must work,’ but rather not argue because it makes you feel dumb,” he explains.

“I learn, and what I learn in the book and the reality here on the plant is a moer of a difference.” He argues that the engineers – his superiors included – are sometimes too fixated on data, using pH levels as law. “We must give the consumers a pure colour, they are not looking at the pH. You can adjust your pH afterwards, first get the colour. I respect the engineers, but they should also come down here and respect me for what I’m doing.”

What Calvin Jafta is doing is vital to Sedgefield’s continued existence. His team are currently paying some much-needed to the boreholes around Sedgefield and placing proper concrete platforms under the pumps. It’s a small maintenance job, but important for the long-term reliability of that water source. The rest of his schedule is filled by regular patrols around the area to police unscrupulous water use. He shares an anecdote about a property that has rainwater tanks and claim to use that for irrigation, but instead use municipal water. Property developers and builders are also popular water thieves who have felt the wrath of municipal fines.

Cape Town’s 2022 doomsday water deadline is fast approaching, but the region’s wine industry contributed R36,1-billion to South Africa’s GDP according to the South African Wine Industry Information and Systems report. The report analysed the industry from 2008 to 2013 and found South Africa to be the eighth largest wine volume producer in the world, providing employment for close to 300 000 people, 56,7 per cent of who are based in the Western Cape.

The agriculture sector, however, accounts for 43 per cent of the province’s water use. With one cubic metre of water only yielding an average of 3,7 kilograms of wine grape (according to Dutch study that referenced satellite imagery and rainfall data from 2004 to 2007), the wine industry has its water conservation work cut out for it.

Andrew Hulsman is a Process Engineer at HWT and the man to talk to when you want to know about the waste water treatment plant at Spier wine farm.

Like in most of the private sector, green initiatives are big currency for Spier. Hulsman explains that the treatment plant reclaims about 150 000-250 000 litres of waste water per day, which then is piped to the toilets on the estate. The effluent is pumped through via six pumpstations and is comprised of waste water from the winery, restaurant, laundry and domestic sewage (poo) from the staff, residents, hotel and public bathrooms.

HWT has a Archimedes Screw patent that they installed to catch large particles, but because some of the waste water is generated in the kitchens of the estate, grease is the biggest problem. The grease caused such regular blockages that the engineers needed a cheaper solution. That solution came in the form of the same plastic mesh bag that your vegetables come in. These are just some of the methods used to preserve the integrity of the billions of bacteria which do the heavy lifting in processing the waste water.

“I like to think of them (the microorganisms) as an ex-wife. You have to make sure she has a home and you provide for the kids, you try and give them the most comfortable life you can and then put up with the occassional issue,” says Hulsman of his relationship with the treatment plant.

The plant is set up in five main processes. First is the mechanical inlet screening which uses the innovative veggie bag filter called the Dragon Sock. Dragon Socks are changed daily and stored on site before being transferred to the municipal landfill once per quarter. Water is then retained four four hours in the flow balancing process. From there the screened and settled water is aerated to remove nitrogen and phosphorus and enters the activated sludge bioreactor where the microorganisms get to work. So far it’s just an ordinary bioreactor plant, but the magic happens when the nitrified water is pumped into the reed bed.

“We selected reeds that were growing nearby because fynbos hasn’t been studied to the extent where we know exactly which nutrients the plants are taking out of the water,” explains Hulsman. The plants get cut down annually to encourage new growth, but the main focus is in the reeds’ ability to strip out all the harsh nutrients carried in the treated water. It’s a natural filtration system which has the added benefit of having developed its own ecosystem of birds, frogs and insects in a similar way the brine stripped off of the desalination plant membranes contribute to healthy ocean eco-systems. “We’ve seen a few threatened species thrive in these conditions and people are always coming out here for bird-watching,” he adds.

The reed bed also serves as a backup to the bioreactor because it contains its own population of microorganisms, while also serving as a water polishing agent.

Although there is no science to support it, flow forms have shown to be effective in this specific water treatment system. And add a nice aesthetic.
Image credit: Lindsey Shutters

Water is then pumped into the circulation pond where it cascades over 15 flow forms. While the effectiveness of water treatement via flow forms isn’t fully understood, the engineers have noticed improvements in a number of parameters. The Yin-Yang shape of the pond is also more aesthetic than functional, but the overflow is then pumped into the irrigation storage dam.

The Ying-Yang pond is a completely ornamental feature. Image credit: Lindsey Schutters

Spier’s vegetable garden is irrigated chiefly from rainwater storage, but the estate gardens are irrigated exclusively from the reclaimed water. The elephant in the room, however, are the endless rows of vines on the Spier property. Hulsman estimates that it takes around five litres of water to produce one litre of wine, and that’s from after the grapes are harvested. Take into account that the Institute of Masters of Wine in the UK reckon a commercial winery has a conversion rate of around 500-850 g per litre of grapes to wine and the fresh water cost is mind-bending. But at least the wine farms are making an effort.

The wine farm is the latest recipient of the Getaway Award for Leadership in Water Conservation at the 2015 Nedbank Green Wine Awards, a testament to Spier’s industry-leading advanced treatment of waste water. In combination with recycling 100 per cent of the waste water on the estate, Spier has removed thirsty alien plants and replaced these with over 53 000 indigenous plants and managed to bring it’s water to wine yield ratio down to about two litres of water per litre of wine through efficient practices.

Zooming out from the country’s dought-stricken greener regions compounds the issues. As much as 60 per cent of South Africa’s water use is chalked up to agriculture and irrigation, and this in a country with a annual rainfall average that’s 40 per cent under the global average, which is enough to be the 30th-driest country in the world.

Every engineer referenced for this article sang the same tune with regards to the country’s water use and it isn’t something we should be dancing about. The situation is dire and it gets progressively worse with every government policy misstep and budgetry blunder. There is a national plan though, and it relies heavily on increasing water reuse volumes through improved purification technology.

Spier’s bioreactor houses an unthinkable number of bacteria, which feast on harmful microbes by interupting chemical bonds. Similar sites are being added to our municipal treatment works. Image credit: Lindsey Schutters

The Blue Drop system of water quality assessment has been heralded as a great success with only five out of the 132 towns tested across the country failing to make the grade in terms fo water quality. This means that although water may become more scarce over the next few years, at least the existing supply is safe to drink. So at least from the perspective of security, our tap water is in a good position.

Andrew Hulsman lets out some of the slurry, which is then sun-dried and sent to the municipal landfill. The high salinity makes it unsuitable for compost in this form.
Image credit: Lindsey Schutters

Under the Blue Drop system the Gauteng Province comes up trumps, with the Ekurhuleni municipality and City of Johannesburg leading the charge to clean water. Acid mine drainage remains a problem, but one restricted largely to coal mines, so the City of Gold is still safe for now. Also, most of the area’s water comes from the Drakensberg.

The overwhelming sentiment is that to get to a point of adequate longterm water security, South Africa needs to implement a step by step plan that will not only reduce consumption, but also reduce contamination. While there are tax incentives in place for the private sector to go off-grid, this has been the exception rather than the rule and understandably confined to newly constructed buildings. The Fair Cape building in Cape Town’s Black River park and Old Mutual’s premises in Century City represent two excellent examples of off-grid buildings. A combination of systems support a central desalination plant and ensures water reclaimation. Further steps should be taken to move agriculture and irrigation over to reclaimed water systems and to take outlying communities off of the municipality supply.

Turning against the agriculture industry will be kissing away the money from our third biggest contributor to the country’s GDP, and condemning millions of people to a life of hunger and poverty.

But the truth is that the responsibility lies with the consumer, me included. Simple things like closing the tap when I’m lathering up, or using only borehole water to water the garden will go a long way to reducing my consumption. I don’t have a swimming pool and I also use the “if it’s yellow let it mellow” code to govern toilet flushing.

Although it would repair a lot of the divisions in our society, maybe not everyone should get a flushing toilet in their home. Not at least until the toilet water is 100 per cent recycled. More services for more people means, ultimately, more sewerage. This will put maintainence budgets more pressure and system failures could then be catastrophic.

Maybe we should all just pray for rain.

Luckily, the government has a plan and it’s called the National Water Resource Strategy 2. In 2013 the strategy called for a R700-billion investment over 10 years to address the estimated year-on-year growth in demand of 1,7 per cent for the corresponding period. Data shows that domestic water consumption rose from 22 per cent of total use in 2003 to 27 per cent of all consumption happening in homes by 2013. A consevative estimate will then see domestic consumption account for roughly a third of the country’s water use by 2023. Our infrastructure isn’t prepared for that kind of load by all accounts.

SA’s network of around 4 395 dams will, under the terms of the strategy, in future be supported by an aggressive water conservation and water demand management campaign, seawater desalination, catchment rehabilitation and a country wide drive to clear invasive alien plants. Water will also become more expensive.

The shades areas are the where all of South Africa’s drinking water comes from. Surface water covers eight per cent of the country’s land mass.

Most intriguing, though, is that 60 per cent of South Africa’s river streamflow is shared through trans-boundary water systems. This calls for policies that are sensitive to the country’s cross-border relations, while still being compliant with legislation governing water resource management. South Africa was recently forced to cut off water supply from the Molatedi dam in the North West to Botswana’s capital Gaborone.

The water supply aggrement was penned in 1988 and accounted for 4,8-million litres of water per day, around 16 per cent of the city’s daily requirements. The original agreement was that supply would be halved when when dam levels reached 26 per cent, but with the region facing its lowest rainfall in 34 years and dam levels at only 8,4 per cent, South Africa had no choice but to take care of its own. A similar move was made by Eskom earlier in 2015 when the government was forced to cut electric supply to Botswana in the face of rolling blackouts.

A key component of the master plan will count on changing the population’s perception: water re-use. At a river system level, it is estimated that approximately 1 800 million m3 per annum of water flowing in our rivers is return flow, that is used water, accounting for 14 per cent of the total available water in South Africa. At the treatment facility level, South Africa has in excess of 1 000 municipal wastewater treatment works, discharging approximately 2 100 million m3 per annum of treated effluent, back to the river systems.

Don’t worry, our municipal water treatment plants are getting the necessary upgrades needed to improve the quality of the final product. The bioreactor in Bellville South in Cape Town is forging ahead down this path of smaller treatment plant footprint and higher quality final effluent.

Bioreactors are not only 60 per cent cheaper to build than regular treatment plants, but half the size and require less maintenance. The 2011 tender for the Bellville South project was around R187-million and the plant receives water from the old treatment facility, essentially acting as a final quality control.

The Karatara weir represents Sedgefield’s first line of defence against the return of drought conditions.

The tap water at the guesthouse in Knysna had a yellow tinge to it and we ended up buying a five litre of still water at Woolworths to make our baby’s formula bottles. My wife actually felt guilty for using tap water to make a bottle on the first night, even though she boiled it beforehand. A simple chlorine-based water clarification pill would’ve gone a long way to calm our parental fears, and it seems like this is the future of drinking water in South Africa.





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