Cape Town’s dirty secret: Daily cocktail of sewage, chemicals is fouling ocean, threatening tourism
A sea-cavorting social media influencer's"swimming in poo" video has sparked a much more serious problem for the tourism magnet that is Cape Town - its centuries-old practice of pumping sewerage into the sea is posing an increasing threat to its tourism boom. One of SA's leading water scientists, Prof Leslie Petrik, unpacks the issue with BizNews editor Alec Hogg.
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Timestamps
00:00 – The Influencer in ‘Salty’ Cape Town Water
01:45 – Cape Town’s Raw Sewage Outfalls Explained
03:54 – Why the City Chose the Sea for Sewage
05:27 – Hidden Health Risks: From E. coli to Flesh-Eating Bacteria
07:10 – The Dirty Secret Behind Cape Town’s Pristine Image
09:24 – Outdated Science and Chemical Contamination
11:23 – Marine Life Contaminated: From Mussels to Penguins
12:56 – Ecological Damage and Fertility Threats in Marine Species
15:29 – Where in South Africa’s Waters Are Still Clean?
16:52 – Nationwide Chemical Pollution and ‘Forever Chemicals’
18:30 – Antibiotic Resistance Fuelled by Sewage Pollution
20:13 – What Citizens Can Do to Make a Difference
22:06 – The Slow Path to Fixing Cape Town’s Sewage System
24:36 – Reducing Household Chemical Use
25:30 – Is South Africa’s Tap Water Safe to Drink?
27:20 – Water Quality in Major Cities
28:07 – Persistent Contaminants in Cape Town’s Drinking Water
BN Reporter
It began with an influencer’s light-hearted video from a Cape Town beach, remarking on the “salty” taste of the sea. Social media’s response was swift and brutal: you’re swimming in sewage.
Behind the ridicule lies a far darker truth – one Professor Leslie Petrik of the University of the Western Cape says has plagued the Mother City for over a century.
Cape Town pumps raw, untreated sewage into the ocean every single day of the year, 24 hours a day, from Salt River to Hout Bay. Three marine outfalls – at Green Point, Camps Bay, and Hout Bay – release the effluent less than 1.2 kilometres offshore. Designed to disperse in the currents, the plumes often drift back to shore, visible from Table Mountain and even in satellite imagery.
“Every time you flush the toilet, that water goes straight into the sea,” Petrik says. “And if you catch the tide or currents at the wrong time, you will be swimming in effluent.”
The problem with “Short-Termism”
The system’s roots date back to the late 1800s, when the Sea Point marine outfall was first planned. Opposition has never stopped, but city administrations have consistently opted for the cheapest short-term fix over expensive infrastructure upgrades.
In the City of Cape Town’s own rankings, the outfalls are a low-priority issue – despite discharging into the city’s premier tourist beaches. Officials argue the outfalls account for only 5% of total sewage generated, but Petrik says the impact on public health and the city’s image is disproportionate.
Testing is limited. Authorities monitor only for E. coli and enterococci, not for specific disease-causing organisms or chemical contaminants. That means there is no direct public record of cholera bacteria, flesh-eating microbes, or viral hazards in the water – even though, Petrik warns, all of these may be present.
More than just bacteria
As a chemist, Petrik’s work focuses on the chemical footprint of modern life. From pesticides in garden centres to pharmaceuticals from pharmacies, and shampoos in supermarket aisles, every product that goes down a drain eventually enters the marine environment.
Wastewater treatment plants, she says, run on technology designed 50–60 years ago – long before most of these chemicals existed. None are equipped to remove them. Her research has found persistent contaminants – including pharmaceuticals like the anti-inflammatory diclofenac – in mussels, starfish, seaweed, fish, and even penguins.
In laboratory tests, sperm from marine species exposed to these chemicals showed reduced vitality, threatening fertility and survival. Similar findings are emerging in parallel research into antimicrobial resistance: bacteria in the environment are evolving resistance to as many as 16 frontline antibiotics.
“The chemical pollution in South Africa is gross,” Petrik says flatly. “We have failed across the board.”
Not just a Cape Town issue
Elsewhere in the country, the picture is equally grim. Where sewage isn’t pumped directly into the sea, rivers carry it there from inland towns and cities. Studies in Durban, Port Elizabeth, and along major river systems point to widespread contamination.
Perfluorinated compounds – so-called “forever chemicals” – have been detected in every waterway tested in a recent national survey. Petrik’s own team has found them in every marine organism they examined.
This national failure, she warns, has far-reaching consequences for human health, marine ecosystems, and the economy.
The tourist risk
Cape Town is marketed worldwide as a pristine beach destination. International cities like London and Paris have cleaned their rivers; failure to address the outfalls could tarnish the city’s brand – and hurt its tourism industry.
Warning beachgoers is difficult. By the time lab results confirm high bacterial levels, two weeks have passed. Efforts to create real-time current modelling for sewage plumes stalled years ago; Petrik alleges political pressure may have played a role.
What needs to change
Upgrading wastewater treatment plants is the first step. Cape Town is investing heavily in some facilities, such as Potsdam, but a fix for the marine outfalls could take until 2050.
In the meantime, Petrik urges citizens to rethink their chemical footprint:
Avoid unnecessary household chemicals and over-the-counter medications.
Refuse antibiotics unless truly essential.
Oppose municipal spraying of verges with pesticides and herbicides.
“Every chemical you use has to go somewhere,” she says. “If it doesn’t degrade, it ends up in the sea – or in you.”
Is our tap water safe?
For now, Cape Town’s drinking water ranks well in national “Blue Drop” reports. Johannesburg’s Rand Water supply is also considered reliable. But in many smaller municipalities, tap water is no longer potable, and in some, the entire treatment system has collapsed.
Petrik’s latest research suggests even Cape Town’s drinking water contains trace amounts of persistent contaminants – far below harmful levels for now, but still detectable.
A long road ahead
Fixing a century-old system of sewage disposal is not quick or cheap. Political will, public pressure, and sustained investment will be essential.
Petrik credits Cape Town mayor Geordin Hill-Lewis for prioritising the issue more than other cities – but warns that without real urgency, the problem will remain for decades.
And for those still wondering whether to take a dip? The professor swims occasionally – but only in the South Peninsula, far from the plumes.