©Jean Tresfon

Sewage in our oceans

Why is there a war of words around Cape Town’s marine outfalls?

In the first half of 2023, a renewed flurry of public engagement began around the issue of sewage treatment and disposal on the coast of Cape Town. Periods of intensified loadshedding had cracked an already creaking waste treatment infrastructure, contributing to sewage spills that saw major water bodies and beaches being closed to the public in the height of the tourist season.

In December 2022, the Department of Environment, Forestry and Fisheries (DFFE) renewed coastal sewage discharge licenses for the Mother City’s three marine sewage outfalls at Greenpoint (for 5 years), Camps Bay (5 years) and Hout Bay (10 years), a decision that was only reached some years after the City of Cape Town had initiated the application in 2015. 

The decision triggered an outcry and appeals, notably from the National Sea Rescue Institute (NSRI) and ActionSA, re-opening a long-running stand-off between the City of Cape Town and those who, amongst other concerns, object to this method of disposing raw sewage close to and within marine protected areas (MPAs).

On Valentine’s Day, Michelle Wasserman of ActionSA photographed floating sewage whilst kayaking off Greenpoint and tweeted about it:

This prompted Councillor Alex Lansdowne, chair of the Water Quality in Wetlands and Waterways Advisory Committee, to take a boat ride to the Greenpoint outfall, after which he published his own salvo on Twitter and Facebook , prompting many objections to his assertions that all was as it should be. The story was widely covered in the press.

A public meeting held in Camps Bay to discuss the issue was attended by a number of longtime activists, concerned citizens and scientists who made presentations on their research and experiences. They were joined by City officials who handed out their own information sheets and took the opportunity when invited to address those in attendance. The fracas on social media continued, for example here and here. 

Subsequent engagements have been less tense, with a glimmer of hope on the horizon that alternatives to current practices are being proactively investigated. In June 2023, City officials including Mayco member for Water and Sanitation Zahid Badroodien met with roleplayers to discuss concerns and their plans for the future. In answer to questions on a #rethinkthestink Facebook post, Milnerton activist and Section 80 Water Quality in Wetlands and Waterways committee member Caroline Marx said the proposal was in essence “…new modern plants at each site is an option being considered. Camps Bay and Hout Bay are relatively small, Greenpoint would require a bigger plant, perhaps built underground with sportsfields on top as has been done elsewhere.” 

There was more good news in June, when the DFFE announced that the public participation process around the outfall licenses in Camps Bay, Hout Bay and Green Point was “inadequate and outdated and needing to be redone” — after which Minister Creecy will review the evidence and make “a final decision as to whether allowing the continued discharge of raw sewage into Cape Towns oceans and marine protected areas is in the public interest.” 

If you are one of the citizens who would like to respond to the issuing of the licenses, this blog post is for you. In it,  we’ve tried to break down and clarify the main issues that are at stake, and to help you navigate what’s being said in the reports, studies and public communication around marine outfalls.

In a statement on 15 June 2023, Mayco Member Zahid Badroodien stated that the City has appointed an independent contractor to conduct the public engagement regarding the discharge permits, and will announce the logistics in due course.

The icky sticky tricky¹ business of ocean sewage disposal

When public comment had previously been requested in the matter of the renewal of the marine outfall licences, there was significant opposition from scientists, public health specialists, marine professionals and recreational users, residents and other concerned citizens. The history of this ocean-borne method of sewage disposal in Cape Town goes back over 100 years, before the city was really a city, and throughout that time, has met with vociferous objections. Nevertheless, city governments have, over the decades, pushed ahead, claiming this to be the most cost-effective and efficient way to deal with the mounting problem of sewage disposal in areas where land is at a premium.

The Department of Forestry, Fisheries and the Environment, not the City of Cape Town, is responsible for issuing Coastal Discharge Permits, which are legally required in terms of the National Integrated Coastal Management Act, and cover both waste water treatment plants and marine sewage outfalls. A stipulation of the licence is that the discharge cannot exceed the carrying capacity of the ocean environment. 

And therein lies the rub. 

Measuring the carrying capacity of the ocean is complicated, and it would take a lot to pay the actual cost of the “ecological services” that nature provides, especially after so many years of racking up debt by externalising these costs. Nonetheless, ecological arguments for a different approach are gaining traction. In the current round of discussions, the main thrust of the objections is that Cape Town is surrounded by Marine Protected Areas (MPAs). All three marine outfalls are either in or nearby to MPAs, meaning that the City is disbursing over 40 million litres of raw sewage into sensitive ecosystems, which are also used recreationally by people. Indeed, kayakers and long distance swimmers have for years documented floating islands of sewage, and complained of getting sick. 

Drawing from the Marine Outfalls Coastal Monitoring report, the info sheet, and CoCT communications on various platforms, the City’s response to objections against sewage discharge in MPAs can be summarised as follows:

• Yes we know it’s not great to pump sewage out into the ocean, but we have the job of dealing with your sh*t and we know what we’re doing. People are getting overly emotional and making claims that aren’t based in Science
• Marine outfalls are an internationally accepted practice; ours operate according to “best practice” and have done so for a century
• The MPAs were declared after the marine outfalls were built, in full knowledge that they were there 
• The sewage going into the ocean is not raw, it’s had preliminary treatment
• Sightings of floating solids and surface slicks can’t be coming from the outfalls as they’re fitted with 3mm sieves; and anyway, the effluent is grey, not brown 
• There are other nearby sources of sewage from stormwater, overloaded sewage works and ships that account for the evidence of sewage pollution of the ocean environment
• The outfalls account for only 5% of the total sewage needing to be processed. The other 95% have a far worse effect on the environment. It’s better to spend the money on inland treatment first, which will make a bigger difference
• We’ve had studies done that say the impact of the outfall is only around the disbursement zone, and that impact is surprisingly low — so we’re ok for now

In all communication around Cape Town’s marine sewage outfalls, a lot hinges not only on the language used, but what it means to be scientific. Let’s look more closely at the word “raw”, for example. The first step of treatment is to push so-called raw sewage through 3 mm sieves to remove all solid items, a process called “preliminary” treatment or “pre-treatment”. At a traditional waste water treatment plant, this sewage then goes through “primary” (easy to confuse with preliminary, but not the same), secondary and tertiary treatment processes, through which the microbial and organic load (faeces, urine, bacteria, viruses) is dealt with. After that, the treated effluent water is discharged back into a river or other water body. This discharge needs to be constantly monitored, and it must meet national guidelines for water quality. 

By contrast, sewage discharged through Cape Town’s outfalls has only, according to public information, had solids removed. According to Bay of Sewage producer Mark Jackson, who is a qualified civil engineer: “The solids have not ‘been removed’ — that is what happens in the primary stage of the treatment process when the solids sink to the floor of the settling tank in traditional WWTW. If the solids were indeed removed here, we would then say the sewage has been primary treated. This is not the case. The ONLY things which are removed by the grids are foreign objects like plastic, grit, towels  etc. This is done to protect the pumps, not protect the ocean… The solid poops in the case of the outfalls are then, instead of settling to the floor as in primary treatment, instead macerated by the pump blades — ground to a pulp, so that they can easily be pumped out to sea.”

Therefore the sewage is essentially still raw when it is pumped to a distance considered far enough out for the deep ocean to “do its business” of diluting away the problem. When the marine outfalls were first constructed a century ago, it was believed that the carrying and processing capacity of the ocean was limitless. And when the Marine Protected Areas were declared, even with the knowledge of their proximity to the marine outfalls, circumstances were very different from today.

The population of the city has ballooned in the past century, driving both formal and informal development, and putting a huge strain on existing infrastructure, the stormwater system, and the natural water bodies to which they are connected. Where infrastructure and services are overloaded, partial or non-existent, nature, and ultimately the ocean, has been expected to pick up an increasingly unrealistic tab.

As to the current extent of this tab, we’ll pick up that burning question in part 2 of this blog: So what’s the big deal about chemicals?

¹From “TIA This is Africa” by Somalian rapper K’Naan