A centre of excellence for nature-based solutions
The Water Hub is an exciting project initiated by the Western Cape Government (WCG) within the broader Berg River Improvement Plan (BRIP) and situated on the banks of the Franschhoek River (a tributary of the Berg River). An inspiring vision for the site will see it become a centre of excellence for research, demonstration and training for new technologies in the water sector.
By partnering with the Stellenbosch Municipality, the Western Cape Government were able to secure the decommissioned Franschhoek Wastewater Treatment Works (WWTW) for re-development. The project team (Isidima, Amanzi Obom Consulting and University of Cape Town) then set to work refining the vision, preparing effective mechanisms to convey it, and developing relationships with various stakeholders.
The vision for the site encompasses three key focus areas:
A significant contribution of world class research in the water sector is produced in South Africa. This is commonly facilitated by Universities, Private Companies and Research Institutions such as the Water Research Commission. The Water Hub provides the unique opportunity of a large site in a beautiful and popular region to base ongoing research projects conducted by these institutions.
Four different water sources are accessible for research at the site including: stormwater from the R45, semi-polluted water in the Stiebeuel River, fresh water in the Franschhoek River and wastewater from the Franschhoek town. These sources enable testing and development of a variety of Water Sensitive Design (WSD) solutions within a South African context.
Further to research activities at the site, the Water Hub will enable demonstration, testing and review of innovative technologies for the water sector. Barriers to market entry for new technologies often include insufficient physical space to demonstrate the product, lacking professional validation and limited access to investment opportunities. Assistance with overcoming these challenges would be found at the Water Hub, along with the opportunity to connect with other professionals in a similar field.
Part of the project vision involves the re-purposing of large activated sludge tanks into an eye-catching conference facility and associated infrastructure for events of up to 300 attendees. Less than one hour's drive from the Cape Town International Airport and surrounded by world-class accommodation, the Water Hub will be a conference venue that all attendees enjoy visiting.
This space will enable training of various forms, and a key focus area will be the training of process controllers in water and wastewater treatment operations. Where better to train operators in new technologies than at the very centre where they could have been developed.
A Recreational Space
Situated in the outskirts of the popular tourist town of Franschhoek, and surrounded by wine farms, the Water Hub could not be in a more picturesque location. The site itself will cater to the general public with paths around the site, technical tours, descriptions of the technologies represented and explanation of research taking place - a visit to the Water Hub will be a fascinating and educational day trip. After a tour of the site, visitors could have the convenient opportunity to walk to the popular neighbouring farm, Rickety Bridge for wine tasting to end the day.
Phase 1 Achievements
The initial project phase involved rehabilitating the decommissioned site and beginning activities to re-purpose existing infrastructure from the WWTW for research and demonstration purposes.
Complete: Administration Block
Re-purposing began with the administration block which had been vandalised and gutted (left), but now has been renovated (right) to provide office space for 3-4 researchers, bathroom, kitchen, outside toilet and two bedrooms when overnight stay is required. Additionally, in accordance with sustainable principles, electricity supply to the building is 100% solar and all wastewater is treated on site.
Complete: Sludge Removal
In order to re-purpose the existing infrastructure as displayed in the video above, old sludge from the decommissioned WWTW had to be safely cleared and disposed. The photographs below show before (left) and after (right) conditions of 2 out of the 7 structures cleared.
Complete: Drying Beds converted to Constructed Wetland 'Biofilters'
Old sludge drying beds previously associated with the wastewater treatment process were in complete disrepair, however their shape and structure were similar to that of common horizontal flow constructed wetlands. With experience in the design of constructed wetlands and related research, Isidima was tasked with re-purposing the drying beds for this new use and incorporating capacity for a range of research.
Designed for Research
The cells were therefore designed to enable complete control of the inlet and outlet flows, with agricultural water meters installed on each inlet for flow measurement. This enables a range of research investigations:
- individual flow: into cell 1 and out of cell 1 or into cell 2 and out of cell 2 etc. This enables assessment of which individual arrangement of the 6 cells results in the greatest improvement of water quality,
- series flow: consecutive flow through 1 > 2 > 3 or 4 > 5 > 6 is possible. This enables assessment of which combination of arrangements is most effective,
- vegetated/non-vegetated: parallel cells have identical media and flow regime, but are planted and unplanted. This enables assessment of the contribution made by vegetation in the treatment process.
- peach pips: whilst uncommon for use in constructed wetlands, peach pips are a waste product from dried fruit production and provide an excellent surface area-to-volume ratio. These cells enable the unique opportunity to assess the suitability of peach pips for constructed wetlands.
Research by the University of Cape Town was aligned with the Biofilter design and is currently underway on: "The treatment of Sediment from Informal Settlements by Natural Systems" by PhD (Eng) student, Sivile Mgese, and supervised by Dr. Kevin Winter. It is anticipated that in time, a number of research projects will be able to make use of this facilty and others like it on the site.
The Biofilter in Pictures
With the design in place, work began on site with the employment of local labour from the nearby Langrug community (read about a related project in Langrug here). From the initial state (below left), surrounding vegetation was cleared and brickwork repaired.
The existing gravel contents were removed (below top row), and recycled for use in two of the cells (bottom left). After clearing the six cells, a compacted gravel layer provided a level base (bottom right).
Pipework was installed that would enable the variety of flow options. Then followed a waterproof lining, protective Bidim layer and finally the filtration media. Three different media were selected to enable testing of the varied effectiveness of these media for wastewater treatment in connection with the vegetation planted.
Once the structure was complete and media in place, vegetation was planted by the research team in May 2017 (left), and has established well by May 2018 (right).
Where to from here?
The University of Cape Town continues to conduct research at the site, and there is ample opportunity for additional research institutions to initiate projects at the Water Hub. Isidima is working with the Western Cape Government and partnering research institutions to secure finance to unlock the complete development of the vision. For more information, to pay a visit to the site, or to contribute to the vision, contact the Water Hub team here.
Thank you for your interest in this article, we trust you enjoyed hearing about the Water Hub,
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