A big step forward for the 360-degree economy in the World’s Favourite City
Images: City of Cape Town
The City of Cape Town’s newly constructed Coastal Park Material Recovery Facility (MRF), running at rated design capacity, dramatically increases the diversion of recyclable materials away from the overburdened landfills that form part of the City’s solid waste handling portfolio.
According to the City’s Mayoral Committee Member for Urban Waste Management, Alderman Grant Twigg, the main purpose of the MRF is to dramatically increase the diversion of recyclable material from
landfills in Cape Town into the hands of the 360-degree recycling economy.
the main purpose of the MRF
is to dramatically increase
the diversion of recyclable
material from landfills…
With a capacity of sorting 65 tonnes of recycled material per day, the MRF allows the City to extend its Separation at Source recycling collection programme significantly. Before this bold new project, the expansion of recycling services in Cape Town was constrained by a lack of sorting capacity, says Twigg.
The MRF was designed to receive comingled clean and dry recyclables, separate them, and make them suitable for sale and use in the manufacture of new products. In doing so, it has created a minimum of 100 job opportunities.
“Increasing plastic pollution is a global issue. It is affecting even very remote environments. Currently, private collection of recycling is prohibitively expensive for many, and the use of drop-offs is sometimes
inconvenient, so I am very excited about this facility. This will allow thousands more families to start cleaning and separating recyclables from their general waste for collection by the City,” he finishes.
However, the design, project management and construction of the new building and its supporting features were not easy, given the highly aggressive weather regime that exists on the site.
Coping with the climatic extremes
The facility is within 500m of False Bay and directly in the path of the notorious South Easter winds that beset Cape Town during the summer months. The highly driven salt and particle-laden winds mean that
the Coastal Park MRF can be considered to be in a severe corrosion risk zone. An extremely severe risk zone is one that both suffers the wind and is directly in the splash zone.
Consideration for the structural elements was particularly focused on galvanising the structural steel, as well as adding duplex painting systems to provide longterm corrosion resistance. Zinc /aluminium alloy-coated steel roof sheeting also provides some additional protection.
According to the City, it has become even more evident during the construction period that the site is prone to “sandblasting” from the nearby dunes, which often block nearby Baden Powell Drive after a sustained period of wind. This sand is lifted into the air and batters the southern-facing sides of the building and infrastructure. The driving wind mixed with sand has the same effect over time as the sandblasting of steel, and strips the infrastructure of its protective coatings. Ongoing maintenance and making provision for the replacement and re-application of protective systems are critical to ensuring the longevity of the facility.
We asked the City’s Solid Waste Department whether any noxious or corrosive gases and odours would be emitted from this site, given that the materials are separated from each ratepayer’s normal household refuse.
“No, generally not” was the reply. “This particular Materials Recovery Facility is what we call a `clean´ MRF, meaning the incoming waste stream for sorting is all clean recyclables, with no intermingled organics (which generally give off an odour).
“As such, there is limited need to make consideration of gas or chemical attack as waste is being handled inside the facility.”
However, they add that for the upcoming project, the Coastal Park Refuse Transfer Station (RTS), which is currently in its feasibility planning stage, more consideration will be given to addressing this issue.
The highly driven
salt and particleladen winds
mean the Coastal
Park MRF can be
considered to be in
a severe corrosion
risk zone.
Materials used in the build
The City says that the MRF is predominantly made of structural steel, but the first 3m of the building is made up of reinforced concrete columns and walls. These provide extra protection from potential damage caused by operations as they move through the facility.
The building is founded on 6m-8m long reinforced concrete FRANKI piles, and all the external and internal floors in and around the MRF are fibre-reinforced except for a small portion around the perimeter walls internally to the MRF. The admin building is made of typical reinforced concrete frames with brick infill.
The roof sheeting and cladding are made from an aluminium-zinc-coated steel sheet, supplied by a South African company coated steel roofing. This was roll-formed into the Saflok 700 profile by Safintra. The
AZ200 steel sheet, made by Safal Steel, was specified as AZ200, TCT 0.53, in manufacturer’s colour Raincloud. In total, 20 000m² of this profile was used for the walls and roof.
The engineering lowdown
Project engineer, Tim Davidson of JG Afrika Engineering provides the technical details: “The roof is supported by 50m spanning structural steel trusses, spaced at 6m intervals, on combined steel lattice and concrete columns. The columns, in turn,are supported on piled foundations driven 6m-8m through the landfill waste on the site to the sand base. Under the roofing is 2-hour fire-rated NC 502 insulation. All the structural steel is galvanised and coated with epoxy paint due to the high corrosivity of the building’s location.
“The roof has prominent elevated box structures in a light-coloured roof material, running parallel to the roof trusses, to provide space allocated for smoke extraction units and smoke curtains in the event of a fire. These are needed as the facility can contain large volumes of highly flammable waste”, he adds.
Davidson says that throughout the design stages, JG Afrika was the civil, structural, and geotechnical engineer and environmental consultant, leading all other professionals as sub-consultants.
During project implementation, however, the initial dispensation continued over the first six months of the construction period, with JG Afrika also acting as the principal agent. In line with the City of Cape Town’s procurement policy, for the remaining 20 months of the contract, WSP was appointed as the principal agent, in turn, sub-consulting JG Afrika to act as civil, structural, and environmental consultants.
They also directly subcontracted the rest of the professional team (see below). JG Afrika also provided the resident engineering services throughout the construction stage.
What’s inside?
The MRF building houses mechanical separation equipment, including a bag splitter, a magnetic
separator, screens, conveyors and baling facilities for various recyclable materials.
The facility also houses offices for the City and operator of the facility, and a training centre for education on waste management.
It provides thousands of households in the vicinity of Coastal Park with a new formal nine-bay drop-off facility that accepts builder’s rubble, mixed waste, garden waste, as well as recyclables not taken by the MRF. The drop-off will also allow for waste reclamation to recover more recyclables and reusable items that would otherwise have ended up in the landfill site.
Accolades received
At an early stage, the project had already caught the eye of the professional community. It was honoured with an award for excellence in construction due to innovative techniques used in the preparatory earthworks, and won in both the Consulting Engineers category in the AfriSam Innovation Award for
Sustainable Construction category against stiff competition, including impressive renewable energy projects, in the Construction World Best Project Awards in 2020.
It went on to be Highly Commended at Construction World’s 2024 Best Project Awards.
The MRF was designed to receive co-mingled clean and
dry recyclables, separate them, and make them suitable for
sale and use in the manufacture of new products.
Professional team:
Client: City of Cape Town
Principal agent: WSP and JG Afrika Engineers (initial stages)
Civil engineers: JG Afrika Engineers
Architects: Jakupa
Landscape architect: Megan Anderson
Quantity surveyors: Talani and BE Clinic
Mechanical, electrical and electronic engineers: CA du Toit
Contractor: Power Construction
Roofing/cladding subcontractor: Chartwell
Site photography: City of Cape Town and JG Afrika
