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Photo: Jay Caboz

A series of innovative floating plastic litter booms has just made its way onto Cape Town's waterways, which will go a long way toward collecting waste that otherwise would have dispersed into the ocean or potentially become hazardous for those living along the riverbanks near it.

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Photo: Jay Caboz

The booms have so far been rolled out along the city's Black River system, which can overflow with tonnes of plastic every year into the sea at Paarden Eiland.

The litter booms are designed to stretch over the surface of the water, catching floating plastic and other debris as the debris moves downstream.

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Photo: Jay Caboz
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Photo: Jay Caboz

The efforts form part of a public private partnership between the City of Cape Town, and two NGOs - The Litterboom Project (TLP) and Pristine Earth Collective - that are conducting a "RIVERLUTION" to clean up water systems in the city. 

"We believe that this first proof of concept will be a starting point for focusing our efforts on river interception systems and revisiting our waste management structure in hotspot areas," said Cameron Service, founder of TLP.

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Photo: Jay Caboz
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Photo: Jay Caboz

Almost 90% of South Africa's marine plastic pollution originates from its own river systems. This amounts to between 15 000 and 40 000 tonnes of marine plastic per year, according to new research published by Carina Verster and Hindrik Bouwman in the South African Journal of Science in June.

TLP is South Africa's first large-scale river interception programme. It began in 2017 as a pilot project collecting waste in the Umgeni River in Durban. Since then, TLP has branched out with more than 20 booms across river systems in KwaZulu-Natal, successfully removing 700kg to 1 tonne of plastic each day.

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Photo: Jay Caboz

Read more: Shocking footage caught tons of plastic crashing in the waves off Durban following heavy rains

Now in the Western Cape, three more booms have been installed near the Black River's Hazendal and Raapenberg intersections, and they are already helping to divert dozens of bags of illegally dumped waste filled with two-litre plastic bottles, bits of polystyrene and even the odd mattress.

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Photo: Jay Caboz
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Photo: Jay Caboz

A second series of booms is currently being rolled out along the Big and Little Lotus Rivers, leading into the Zeekoevlei, which flows into False Bay.

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Photo: Jay Caboz
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Photo: Jay Caboz

The litter booms are designed with simplicity in mind.

Made from 90mm HDPE plastic piping, the booms are buoyant enough to float on the surface of the water.

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Photo: Jay Caboz

The HDPE plastic is also sunproof and does not degrade over time, making it safer for the environment.

"[The litter booms] are placed at an angle to ensure waste flows towards the most accessible bank. This is the most efficient method to collect waste we have found, and is also a lower risk as staff do not need to wade deep to collect waste," said George van der Schyff, director at Pristine Earth Collective.

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Photo: Jay Caboz

Sealed on both riverbanks, the booms are cleverly designed to break at one end under extreme pressure and prevent them from being washed away in floods.

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Photo: Jay Caboz

The litter booms do not make use of nets below the water surface, which TLP says can create a dam wall effect and clog up the natural river water flow and potentially negatively affect life in the river.

"The Black River needed a real working interception...It is the first part of a journey upstream towards solving the source of the problem with the next stop being community engagement and tackling illegal dumping and helping to create a more sustainable economy around plastic in underserved areas," said Van der Schyff.

Cape Town plans to roll out more litter booms

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Photo: Jay Caboz

"While the concept of booms isn't new, resource constraints have made it unsustainable for the City to implement and maintain them on our own – as is typical of developing countries. We are, however, very much open to supporting community-led initiatives in this space where we can, and are excited at the opportunity to demonstrate what a 'river protection partnership' can achieve," said Abdulla Parker, the City of Cape Town's head of catchment planning.

For the project, the City is only responsible for removing the non-recyclables. Other stakeholders are responsible for installing, maintaining, and clearing the booms.

"This reduces the strain on the City's budget by almost 98%, making this seem like a much more feasible model for improving the state of our rivers. This is a model that we would like to explore elsewhere in the city, wherever there is interest," said Parker.  

The recyclable plastic will be upcycled and collected weekly by Vukuzenzele Multi-Recycling, a female empowerment co-operative in Philippi. 

"It's a very simple concept. Extremely simple...This is a medium- to long-term plan to improve our stormwater quality with innovation."

Because the litter booms are made from cheap material, they offer a much-needed solution to deterring criminal elements from vandalism and theft. 

"An important advantage of this type of project is that the cost is minimal [for] a litter boom, instead of litter girds that often get vandalised or stolen," said Parker.

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Photo: Jay Caboz

While the project is exciting, the perfect scenario would be for residents to prevent litter from ending up in rivers in the first place. According to Parker, the cost of cleaning up the waste in rivers, and then removing that waste, can be as much as 10 times more expensive than if it had been disposed of properly in the first place.

"Collaboration is key when it comes to tackling problems of this scale. Pollution is a whole-of-society challenge that requires a whole-of-society solution. It is hoped that not just the project itself, but awareness of it, will inspire behaviour change and in time, see a reduction in the volumes of waste discarded into our natural environment," said Alderman Xanthea Limberg, mayoral committee member for water and waste.

The project is looking for local corporate partners to provide funding and resources to upscale to more river streams.

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