Sewage flowing into Kuils River creates a health hazard for all of Cape Town
The Zandvliet Waste Water Treatment Works is in crisis, discharging sewage into the lower Kuils River and causing horrific health effects for the people who live along the river. But an injury to one is an injury to all. The entire False Bay is affected.
On two Tuesdays in November, Cape Town had a light summer rainfall. Nothing unusual; just a light shower — about 2mm — on the 20th, and a little more around the 27th.
But after both rains, the Zandvliet Waste Water Treatment Works (WWTW) discharged millions of litres of what we observed to be raw, unfiltered sewage into the Kuils River, via a channel known as the Kakrivier (“Shit River”) by locals, bulldozed for this purpose by the City of Cape Town.
That these discharges happened just after two light rainfalls suggests that stormwater is entering the sewage system. It would seem that on both occasions Zandvliet WWTW had been overwhelmed.
East of Khayelitsha, south of Somerset West, and a few hundred metres from the waves of False Bay, the treatment works regularly discharge sewage along the channel. Over time, this has made residents downstream at Sandvlei horrifically ill.
Over the past few months, Councillor Ganief Hendricks, head of the Al Jama-ah Party, has requested provincial and national investigations on behalf of Sandvlei residents.
The result: on 22 November, Aqueel Yasin, of the Western Cape Directorate of Environmental Affairs and Law Enforcement, issued a “pre-directive” to the City’s municipal manager. Yasin warned that the City was in contravention of the National Environmental Management Act and the Waste Act, and that the Environmental Management Act “makes provision for the criminal prosecution of officials of an organ of state”.
The pre-directive was issued to allow the City an opportunity to make its case as to why that directive ought not be issued, which would require action within 30 days. Non-compliance with a directive, he noted, could result in a fine of R10-million, or 10 years’ imprisonment.
Dr Gisela Kaiser, executive director of Informal Settlements, Water and Waste Services for the City of Cape Town, responded by arguing that the particular legal provisions in terms of which the directive would be ordered, do not apply.
Kaiser claimed that Zandvliet WWTW discharges only treated effluent. The upgrade of the treatment plant, she noted, was being delayed as the tender had been contested.
Our own laboratory results from samples collected in the river after the rains were heavily contaminated with E.coli, a bacteria that is used in research as an “indicator organism” to monitor environmental conditions.
While the City argues over which of the finer points of law and science should be brought to bear on how to discharge their duties, the citizens of Sandvlei along the Kuils River below the discharge point are suffering an array of medical complaints so severe that they have resulted in surgical interventions (for E.coli poisoning of the intestine or the cardiac system), or the need for shopping-bag quantities of medicines for sinus and respiratory infections.
Staphylococcal skin infections are rife, as is eczema. An accidental dip of a foot into the river resulted in sores appearing on the skin a few days later. Animals are ill; horses have died from drinking the river water. A Sandvlei horse breeder’s account of one of his horses giving birth to a foal without back legs is the sort of extreme consequence that drinking heavily contaminated, chemical-laden water could cause.
These are the kinds of stories that are invisible to the forms of techno-scientific governance that currently dominate city management. Governance by occasional assessment of E.coli or water turbidity may appear to be “solid science” — but when and where a sample is collected, and how long it is left before it gets to the laboratory, can profoundly change the numbers.
When governance does not check its numbers against the on-the-ground reality, or when it uses science to conceal real suffering, the science is serving power — not people.
Science undertaken by city employees whose jobs rely on providing a good scientific account, or by consultants chasing the next contract, are not independent, objective or reliable. That the city’s science has made invisible what people are experiencing, is an indication that it needs a review. The claim that all science, and any science, no matter when or how done, is authoritative truth fit for governance, is not scientific.
Further downstream, at Macassar, the Kuils River joins the Eerste River and goes to the sea, entering into the waves of False Bay near the beaches at Strand, Monwabisi and Wolfgat.
The difference between the Kuils/Eerste River sewage-to-sea and the city’s several off-shore marine outfalls, however, is that the river discharges into the waves, which means that whatever microbial or chemical load it was carrying will flow along the sea’s edge. In False Bay, the water tends to circulate clockwise, towards Strand and Gordons Bay, where historically several marine die-offs have occurred due to “red tides” or other algal blooms. That sewage also contains serious chemical pollutants.
The City’s half-dozen marine sewer outfalls have been the subject of ongoing complaints from ocean-users, ratepayers and scientific researchers. Yet City officials have neglected to act on the effects of the tens of millions of litres of sewage that it daily discharges to its surrounding oceans.
When a Council for Scientific and Industrial Research (CSIR) report commissioned by the City was finally made public in November 2017, the Mayco member responsible for water and sanitation, Xanthea Limberg, said in a press release:
“A study by the Centre for Scientific and Industrial Research (CSIR) into the City’s sea marine outfalls has confirmed that they pose nosignificantrisk to human health and do not measurably affect inshore water quality or the wider environment.”
But the actual CSIR report stated quite clearly in its one-page conclusion that:
“It is… illogical and indeed irresponsible to imply that effluent discharged through the outfalls is not impacting on the marine receiving environments or posing a potential human health risk. Indeed, the notion of no impact to a marine receiving environment in the context of effluent discharge is unfounded.”
Clearly, whoever wrote that paragraph had in mind that the complexity and fragility of the ecology of an urban ocean requires far better thinking than single-issue science.
While a Fisheries official confirmed that the green bloom in False Bay in the past few weeks was not a toxic variety, for example, its lack of toxicity should not be considered “solid science” that spells the end of any care about what is happening in False Bay.
A dense non-toxic bloom can cause mass fish death when it dies off. Moreover, the orange tide occurring elsewhere in False Bay —Noctiluca scintillans, which is one of the phosphorescent planktons that lights up when disturbed — is also associated with “excessive nutrients” (that is, from sewage and fertiliser run-off) and has also been linked to fish deaths in scientific literature, not because it is toxic, but because it can accumulate toxic levels of ammonia.
So within an urban ocean the phytoplankton that should be part of a normal upwelling coastal ecology can change ocean chemistry into something harmful.
The poorly treated sewage discharge is a likely explanation for the findings of Leslie Petrik and Cecilia Yejide Ojemaye in Environmental Chemistry at the University of the Western Cape, who have been researching fish contamination in False Bay in 2018.
Their findings have been astonishing: the flesh of several False Bay fish species including snoek, bonita, panga and hottentot are heavily contaminated with persistent contaminants deriving from pharmaceuticals, body-care products and cleaning materials.
In other words, ocean contaminants cannot come only from surface run-off, as City officials have claimed. The particular combination of chemicals detected could only come from both sewage and urban and agricultural surfaces.
Chemical pollutants are measured in nanogram-per-gram dry weight (ng/g dw) or micrograms per kilogram (µg/kg dw), so 1 ng/g is the same as 1 µg/kg).
In fish, concentrations of herbicides such as the compound atrazine — which is used in South African vineyards and as a weedkiller on city pavements — ranged up to 50 µg/kg dw (or 50 micrograms per kilogram, or 50 nanograms per gram of dry weight) in the fish fillets. Atrazine is banned in the European Union because of its persistence in groundwater and health effects such as endocrine disruption, cardiovascular problems and cancer. It causes immense damage to the reproductive system of frogs, for example.
Another EU-banned herbicide,simazine, ranged up to 157.82 µg/kg; metolachlor up to 94.30 µg/kg. Alachlor and butachlor (which may cause organ damage) were found in the fish fillets in a lower concentration. However, the levels of these herbicides in individual fish were generally higher than the United State Environmental Protection Agency (USEPA) limit of 100 ng/L.
The team also found the presence of at least 12 other persistent organic compounds at nanogram-per-gram dry weight (ng/g dw) concentrations in different parts of the same fish samples, including harmful industrial chemicals such as perfluorodecanoic acid(20.13-179.19 µg/kg), perfluorononanoic acid(21.22 – 114.04 µg/kg) and perfluoroheptanoic acid (40.06 -138.28 µg/kg).
Since no-one eats only a gram of fish at a sitting, but more likely 200g (wet weight) or more, this would increase the dose taken in per meal considerably — and never only of one compound, but a whole cocktail of chemicals.
Other pharmaceutical compounds such as acetaminophen (analgesics/anti-inflammatory), diclofenac (analgesics/anti-inflammatory), lamivudine (antiretroviral), phenytoin (anti-epileptic), sulfamethoxazole (antibiotic), carbamazepine (anti-epileptic), and caffeine (yes, from your daily cuppa), were also found to different degrees in various parts of the fish sampled.
The most worrisome of these compounds was diclofenac, a notorious non-steroidal anti-inflammatory drug (NSAIDs), commonly sold as a painkiller, but which may increase the risk of stroke, heart attack, and cardiovascular risks and has had catastrophic effects on vulture populations — to the point where some species are at risk of extinction.
It had the highest concentration in fish fillets (range: 551.76 — 1812.32 µg/kg) out of all the pharmaceuticals detected.
The Zandvliet WWTW is almost 30 years old, and services the waste water produced by close to a million people in the south-eastern region of Cape Town. That means it is processing not only the excrement of about a million people, but every medicine we use; every household cleaning fluid ranging from washing powders to drain cleaners, and every personal care product ranging from shampoos and toothpaste and shaving creams to deodorants and perfumes.
The raw effluent contains the contents of just about every consumable product in every supermarket and pharmacy, from food to household cleaners to medicines. And the liquid waste from every factory. The presence of caffeine in the fish points to the large coffee habit of Capetonians.
The responsibility for cleaning up after city people falls to waste water treatment plants. In the case of the Zandvliet WWTW, many of the chemicals and pharmaceuticals the plant should be taking out were not even invented in 1988 when the plant was designed. Endocrine disruptors, for example, were only identified as a health problemby scientists as recently as the early 1990s. Antiretrovirals present a similar problem.
According to a 2016 study of the Zandvliet WWTW, the plant did not effectively remove perfluorinated compounds nor atrazine from sewage. All the tested pharmaceutical compounds and many others were present in the sewage effluent.
That study links the inefficient sewage treatment directly to the contaminated fish — in the sense that all these compounds were found in the Zandvliet sewage and now in the fish. The diverse contaminants, including pesticides, as well as antibiotics and diverse pharmaceuticals, found in all parts of the sampled fish to different degrees, can thus only have originated from sewage discharges into the marine environment of False Bay. These findings indicate that sewage is impacting on the urban oceans of the Western Cape severely.
Of major concern in effluent-dominated water is the release of persistent organic pollutants that do not break down easily, and bio-accumulate in ever-increasing concentrations up the food chain. Pharmaceuticals, for example, are designed not to break down easily, because their molecular structure needs to withstand stomach acids and their action is at cellular or subcellular level.
Even compounds with relatively short environmental half-lives may be considered pseudo-persistent in situations when they are continuously discharged from a wastewater or sewage treatment plant.
The risk assessment levels for these compounds in fish were well above 0.5 and 1.0 for acute and chronic risk respectively, which shows that these chemicals pose a significant health risk to the aquatic organisms and humans who consume them. Eating foods contaminated with such persistent lipophilic (fat-loving) chemicals can result in the accumulation of these chemicals in humans.
The potential for chemical residues to cross the placental barrier, even in trace concentrations, may cause serious damage in newborns and therefore raises great concern. From these findings, it seems that fish caught in relatively enclosed urban oceans like False Bay are a major source of contamination for both top marine predators and people who eat these fish.
The big picture here is what climate scientists and geologists call “the Anthropocene” — this era in which humans (“anthropos”) change ecologies to such a level that they change Earth systems. The Anthropocene involves more than just carbon dioxide emissions. The need for different kinds of thinking in planning cities is urgent: that much is clear in the dystopic, almost apocalyptic health situation faced daily by those who live along the Kuils River below where the effluent stream joins it.
The big picture here is of municipal and regulatory failure, but not only that. It is a situation that points to the failure of the ways in which we city people imagine that waste produced at mega-city scale can simply be absorbed by the environment.
“Nature” is not — and has never been — something National Parks puts behind a fence and tourists visit on vacation. We humans arenature: our bodies are fragile ecosystems of microbes and molecules, and we are the rivers and rains that we drink.
Human waste is currently imagined as something that disappears with a flush, but the idea that put-it-in-a-pipe is a solution, is pie in the sky. It is a belief system as bad as the idea of a “flat earth”. The Earth is made of cyclical systems, and toxins never disappear. What we put into our households and our bodies becomes geology. Wherever did we get the idea that toxic chemicals make homes clean? The geologies we are making with the chemicals that we put into our sewers, and on our bodies, and in our houses can break local ecologies. In time, that affects our own health, and future generations, and will lead to species extinctions.
Just as carbon dioxide emissions don’t disappear in the atmosphere, so too don’t chemicals or pharmaceuticals disappear in a river or the sea. Outputs from households become urban ecologies. The urban ecologies we are making affect everyone and every species which has any connection with local waters and ecology — even into the far future.
In the 1960s there were ±3.5 billion people on the planet. Currently, there are about 3.5 billion urban people in the cities of the planet and another four billion outside of them. A great deal more foresight and planning is needed to prevent the collapse of our fragile world caused by the excrement and chemicals generated in ever-growing consumer societies.
Fighting over which rules apply instead of acting, and governing by techno-science that excludes local experience, is an indictment on our City. It is failing in its legal duty of care.
It is also an indictment on consumers, as we continue headlong with our thoughtless use of chemicals and the belief that consumerism and economic growth — at the cost of ecologies — is the solution to well-being.
People are suffering the presence of human excrement all over South Africa, whether it be in pit latrines, through non-functional waste water treatment works, or the release of sewage-borne chemicals and pharmaceuticals into ecologies and food chains.
The current Green Drop standards which regulate the disposal of wastewater are not adequate for protecting South African citizens, and need updating to international norms, since even in the best-working waste water treatment works these compounds are still escaping into the environment. The technology typically being used is outdated and unable to deal with chemical compounds, due to their molecular dimensions and structural properties. Yet South Africa has sponsored some of the most innovative research into solutions.
As Cape Town’s drought was a warning, so too is the contamination of the Kuils River, Eerste River and False Bay. We need a completely different approach to chemicals, medicines and sewage. Earth systems have limits. DM
Lesley Green is Professor of Anthropology and Deputy Director of Environmental Humanities South at the University of Cape Town. Her book Rock | Water | Life: Ecology and Humanities for a Decolonising South Africa will be published by Duke University Press in 2019.
Leslie Petrik is Professor of Chemistry at the University of the Western Cape and leads the Environmental and Nano Science Research group there, with a focus on environmental pollution, remediation and treatment.
Nikiwe Solomon is completing her doctoral dissertation on the Kuils River and its residents, users, and multi-species communities and their entanglements with social and political worlds in urban planning. She is a Lecturer in Anthropology at the University of Cape Town where she is affiliated to Environmental Humanities South.
Cecilia Yejide Ojemaye is completing her PhD in Chemistry with a focus on persistent contaminants in the marine environment from Green Point to False Bay.
Silvia Inés Romero is Professor of Physical Oceanography at the National University of Buenos Aires, Argentina. She has a research position at the National Hydrographic Office with focus on biophysical interactions at chlorophyll-a hot spots in the Southwestern Atlantic Ocean and their spatial and temporal variability.
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