The Umgeni River system supplies drinking water to about five million people in the city of Durban, South Africa. But demand for water has outstripped supply for the past seven years. Pictured here is Howick Falls, which lies on the Umgeni River. Credit: Brendon Bosworth/IPS

By Brendon Bosworth
KWAZULU-NATAL, South Africa, Oct 1 2013 (IPS)

In a few years, residents of the eThekwini municipality in the port city of Durban in South Africa could be drinking water that was once flushed down their toilets, as authorities are planning to recycle some of the municipality’s sewage and purify it to drinking quality standards.

“We’re going through a crucial water shortage, which is increased by the water demand of eThekwini,” Speedy Moodliar, the municipality’s senior manager of planning for water and sanitation, told IPS.

The municipality relies on the Umgeni river system for water. But demand on the system, which supplies drinking water to about five million people and fuels industry in the economic hubs of Durban and Pietermaritzburg, a town 66 kilometres from the coast, has outstripped supply for the past seven years.

To boost supply in future, the South African government has proposed building a dam with a capacity of 250 million cubic metres on the uMkhomazi river, the third-largest river in KwaZulu-Natal, and transferring water to the Umgeni system.

But this scheme will only be operational by 2024 at the earliest, said Moodliar. “Between now and when the uMkhomazi [project] comes online, [wastewater] re-use will be our mitigation measure.”

In dry countries like Israel, Egypt, and Australia treated wastewater is used for industry, landscaping and agriculture. But worldwide few countries put it directly into their drinking water supplies.

Singapore uses purified wastewater to meet 30 percent of its water needs, although just a small percentage goes to drinking water and the majority is used by industry. Citizens of Windhoek, the capital of South Africa’s arid northwestern neighbour Namibia, have been drinking recycled wastewater for over 40 years.

In 2011 the Beaufort West municipality, which serves close to 50,000 people, began treating its sewage for use as drinking water after a vicious drought, making it the first in South Africa to do so. According to a 2012 World Bank report “The future of water in African cities: why waste water?” few cities in Africa have functioning wastewater treatment plants and “only a small proportion of wastewater is collected, and an even smaller fraction is treated.”

eThekwini municipality plans to upgrade two of its existing, and underperforming, wastewater treatment plants – the KwaMashu and Northern treatment works, Moodliar explained.

To remove contaminants and clean the water to drinking quality standard, a three-stage system that treats effluent through ultra-filtration and reverse osmosis, as well as disinfection by ultraviolet light and chlorine would be used. The treated water would also be stored and tested before being released.

The purified water will be mixed with conventional drinking water at a ratio of 30 percent re-used water to 70 percent conventional, said Moodliar. It will feed the municipality’s northern regions, including Umhlanga, Durban North, Reservoir Hills, and KwaMashu.

Re-using wastewater in this way will add 116 megalitres of tap water to the municipality’s supply daily. This is enough to fill just more than 46 Olympic-size swimming pools. It is roughly 13 percent of the municipality’s current daily consumption, and will provide an estimated seven years of water security.

While it will cost more to produce drinking water through wastewater recycling – about 75 cents per kilolitre compared to 50 cents per kilolitre for conventional treatment – the municipality sees it as “the best fit,” said Moodliar.

The municipality has touted the effectiveness and safety of the proposed system, but there has been opposition to the plan, including the submission of a 5,000-signature petition during the public participation process last year.

Citizens have raised concerns about the safety of drinking the re-used water. “Recycling of toilet water to drinking water is a death sentence to the general public because of health implications,” wrote Jennifer Bohus in an email to Golder Associates, the firm that produced the basic assessment report for the wastewater recycling proposal.

The municipality, however, maintains that the water will be fit to drink.

“The technology is advanced enough that the quality of the water being returned is high,” Graham Jewitt, director of the Centre for Water Resources Research at the University of KwaZulu-Natal, and chair of water resources management for state-owned Umgeni Water, told IPS. “Many cities all round the world use recycled water.”

“About 14 percent of water use in South Africa is actually water that’s being re-used, most of it indirectly,” Niel van Wyk, chief engineer with the Department of Water Affairs, responsible for strategic water resource planning in KwaZulu-Natal, told IPS.

Citizens opposing the plan also said the municipality, which loses 36 percent of its water annually, largely through leaks and illegal connections, should focus on fixing leaking pipes. Others proposed investment in seawater desalination plants, instead.

The potential for sucking seawater from the Indian Ocean and converting it to freshwater for the region is currently under investigation. But the process of seawater desalination, which involves pumping saltwater at high-pressure through a semi-permeable membrane that retains the salt, and allows water to pass through, remains costly.

Umgeni Water, the state-owned company that is the largest supplier of bulk potable water in KwaZulu-Natal, is doing a feasibility study for two desalination plants: one on the south coast, adjacent to the Lovu River, and one on the north coast near Tongaat, Shami Harichunder, corporate stakeholder manager for Umgeni Water, told IPS.

If built, these plants would be the largest desalination operations in the country, each capable of producing 150 megalitres of water a day. By comparison, the largest desalination plant in South Africa, in Mossel Bay in the Southern Cape, produces a tenth of that amount.

The cost to build one of the proposed plants is as much as 300 million dollars, according to Harichunder. The required technological components, like high-pressure pumps, are expensive, he said.

Desalination plants, however, can be built more quickly than large dams and transfer infrastructure, and also scaled up in future if needed, said the Department of Water Affairs’ van Wyk.

Umgeni Water’s feasibility study is to be completed in December this year. And the feasibility of building desalination plants will be compared to that of the proposal to dam the uMkhomazi river, said Harichunder.

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South Africa’s 232-kilometre Umgeni River is clean upstream but the closer it gets to the sea, the dirtier it becomes. Credit: Brendon Bosworth/IPS

By Brendon Bosworth
HOWICK, South Africa , Aug 14 2013 (IPS)

Over the course of a 28-day trek down South Africa’s Umgeni River, which flows from the pristine wetlands of the Umgeni Vlei Nature Reserve to the Durban coastline, Penny Rees, a coordinator for the Duzi uMngeni Conservation Trust, witnessed the polar opposites of river health.

The trust is a nonprofit organisation that works to conserve the Umgeni and its tributary, the Msunduzi river. At the Umgeni River’s source the water ran clean and was good enough to drink for Rees, and the four volunteers who joined her in walking the length of the 232-kilometre river and documenting its health. Further downstream, after the river had wound past agricultural land and urban terrain, the water became sludgy and smelly.

“Sometimes you can smell it, like [we could] in Durban the last time we crossed the river,” Rees told IPS during an interview at her home in Howick, 97 kilometres north of the port city Durban. “You get to know the colour of the water – [it has] this grey, grungy look, and it stinks of sewage.”

The Umgeni River supplies drinking water to more than five million people, and is the main source of water for the cities of Durban and Pietermaritzburg town 66 kilometres from the coast. Rees’s sojourn further highlights the work of scientists who have pinpointed pollution problems in the river.

Ongoing sewage sagas

Like other rivers in South Africa, the Umgeni is under pressure from untreated sewage entering it. Poor infrastructure and surcharging sewers in places like Mpophomeni, a low-cost housing settlement upstream of Midmar Dam, have led to high levels of E. coli and nutrients flowing into the dam, Simon Bruton, a hydrologist with environmental consulting firm GroundTruth, told IPS. Midmar Dam is a large dam with a capacity of 235 million cubic metres of water on the outskirts of Pietermaritzburg.

While Mpophomeni accounts for just 2.4 percent of Midmar Dam’s catchment area, it produces about half of the E. coli and 15 percent of the phosphorous entering the dam, according to a 2009 study by GroundTruth.

Projections indicate that the sewage pollution entering the Umgeni River, combined with nutrients from run-off from dairy, pig and poultry farms, could lead to Midmar and the nearby Albert Falls Dam becoming “eutrophic” – rich in nutrients like nitrogen and phosphorous that promote algal growth – by 2019.

When dams enter this nutrient-rich state, algae grows in them.

“A lot of the algae that blooms can be toxic to human contact so you wouldn’t be able to use the water for recreational purposes any more,” said Bruton. “The other problem it creates is that it significantly pushes up the water treatment costs because that biomass of algae causes problems for water purification, and it’s quite costly to remove.”

Overburdened wastewater works

Wastewater treatment plants that empty treated effluent into the river are also oversubscribed, adding to contamination issues. At four of the plants operated by state-owned company Umgeni Water, compliance rates for the quality of treated water pumped into the river dropped to 71.6 percent in June 2013, according to an Umgeni Water audit report. A compliance rate of 95 percent is considered acceptable.

The overall lack of compliance was chiefly due to problems at the Darvill plant, which treats industrial and domestic wastewater from the city of Pietermaritzburg.

The Darvill plant is overloaded, Shami Harichunder, corporate stakeholder manager for Umgeni Water, told IPS. The company has put out a tender valued at millions of dollars to increase the plant’s capacity by over 50 percent, and has spent about 500,000 dollars on additional aeration facilities, which are soon to be commissioned, he said.

Companies that pump industrial effluent to the plant, and fail to meet their permit obligations for the quality of effluent they discharge, also “significantly” affect the plant’s ability to process wastewater, Harichunder said.

However, compliance at the Howick plant, which is running near to full capacity, was at 90 percent for June 2013.

Downstream pollution

Earlier this year, the Umgeni River made headlines as “one of (the) dirtiest” rivers in South Africa, based on the release of a study for South Africa’s Water Research Commission. The study analysed levels of viral and bacterial contaminants in the section of the river that stretches from Inanda Dam, close to Hillcrest, to the river mouth in Durban.

The researchers found bacteria, including salmonella and shigella, as well as viruses, such as Hepatitis B, in every sample they took.

Many of the bacteria and viruses found in the samples are potentially pathogenic to humans and have demonstrated the ability to kill human tissue cultures, one of the study’s authors Johnson Lin, who is based at the University of Kwa-Zulu Natal, told IPS.

The river water failed to meet the Department of Water Affairs and Forestry’s water quality guidelines for recreational and drinking use. The results “would raise concerns for people who may consume water directly from the river without any form of treatment,” the researchers concluded.

Lin points to outbreaks of diarrhoea as a potential risk to those who drink contaminated river water. And the paper highlights that in South Africa, 2.6 percent of all deaths are attributable to unsafe water supplies, and inadequate sanitation facilities and hygiene.

River shows its strength

During their month-long sojourn, Rees and her team documented other negative impacts on the important river. They saw the detrimental effects of sand mining operations, illegal dumping of trash on the river’s banks, along with the proliferation of invasive aquatic plants that thrive in high nutrient conditions created from agricultural run-off and sewage contamination.

Despite this, Rees was struck by the fact that, based on the water sampling the team did, water quality could once again improve in sections of the river that were not impacted by human activity for long stretches.

“The miracle is that if you give [the river] a long enough gap without any impact, the water returns to top quality,” she said.

With that in mind, Rees is advocating designation of untouched buffer zones between major contamination points along the river. “You’re always going to have a spill from a wastewater works, sooner or later,” she said. “At least then you know that if there’s a problem you need x-number of kilometres where there is no impact and the river will [be] clean.”

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