Innovating sanitation provision to informal settlements
Video by: FLOW - for love of water
The Genius of SPACE (Systems for People's Access to a Clean Environment) project set out to innovate and demonstrate an alternative method of greywater management, solid waste management and stormwater drainage in an informal settlement context. Initiated as part of the Western Cape Government's broader BRIP (Berg River Improvement Plan), the Genius of SPACE project brought together a diverse project team including Greenhouse Systems Development, Isidima Design and Development, Maluti GSM, Informal South, h20, CORC, John Todd Ecological Design, BiomimicrySA, Freshwater Consulting, and Stellenbosch University.
Now, 18 months since the completion of the greywater management phase, we take a moment to review the project to date. The video above provides a short summary of the project, produced mid-way through the construction in April 2016. In this article we talk through the various components of the greywater management system in further detail.
Langrug Informal Settlement Context
Langrug is situated on the outskirts of Franschhoek, a short way off the R45, and adjacent to the Stiebeuels River. Home to over 2500 households, growing daily and positioned on a steep incline, sanitation provision to Langrug is challenging. The Stellenbosch Municipality has provided centralised toilet blocks within the settlement with a maximum accessible walking distance of 200m for residents.
Whilst the municipality intends to upgrade the settlement with formal services in due course, the high household density, rapid population growth, topography and budget constraints will likely delay upgrades for a number of years. Residents commonly collect buckets of water at the toilet blocks for bathing, clothes washing and kitchen cleaning at their households. This generates 'greywater' which is disposed just outside the home; forming streams in drainage channels and flowing into the Stiebeuels River, Franschhoek River, and eventually the Berg River. Pollution levels in the Berg River have been increasing annually, and this can significantly affect the quality of export fruit grown with irrigation water from the river.
This greywater disposal poses a number of health issues to residents as streams of foul smelling, highly polluted 'greywater' (with E.coli measured above 30 million counts/100ml) flow through the settlement between the houses. This is worsened by the presence of a large population of stray dogs. Residents reported that a number of children, and subsequently adults, developed illnesses and skin conditions from inevitable contact with this water. These issues further burden already inundated local clinics.
Enter: Genius of SPACE
Selecting a pilot site of 125 households in the settlement, a Project Steering Forum (PSF) was set up through an open election process by the Langrug Community. When time came for construction, a list of labour skill requirements was provided to the PSF who conducted a random draw from interested Langrug Community members who matched the skill requirements. Isidima then managed the selected labour team who performed all construction activities.
In the conceptual design phase, the project team looked first with a Biomimicry lens at the current genius within the community where informal examples of greywater disposal points had been erected by the residents (below: top right). Learning from these early attempts by the community to manage the greywater problem, Isidima worked together with Maluti GSM Consulting Engineers to develop a formal, robust solution.
The first component of this was the 'Disposal Points' (below left and bottom) - 29 simple, 50L drums shared by up to five households each. These provide initial filtration of the greywater before discharging it to a pipe network. The Disposal Points were deliberately designed as a low-tech component that can be operated and maintained by the community themselves - this has been the case to date for 18 months of operation.
In-situ pipe laying follows existing pathways
A flexible HDPE pipe was selected for branch connections between the disposal points and two 110mm trunk lines. This enabled the pipework to snake along existing informal pathways; minimising connections and bringing disposal points into convenient proximity for each resident of the pilot site. The two 110mm trunk lines then deliver the filtered greywater to a series of 'Tree Gardens' for further polishing. The map below shows the layout of various components.
Colour coding; Dots: Disposal Points, Tree Gardens, Lines: 63mm HDPE pipe, 110mm uPVC pipe
Filtered greywater from the disposal points flows through the pipe network and into a series of 13 'Tree Gardens'. Holes roughly 1.2x1.2x1.2m were excavated and filled with a combination of in-situ soil, biochar and compost. An indigenous, water-loving tree was planted, and an inlet point installed to receive the filtered greywater from the trunk line and disperse it sub-surface into the Tree Garden area.
The Tree Gardens contribute to the system by providing passive ecological treatment and infiltration of the recycled water, and in-turn provide shade and aesthetic greening to the surrounding houses and pathways.
Sustainable urban drainage: permeable paved road
A further intention of the Western Cape Government through the Genius of SPACE project was to demonstrate the potential of using Sustainable Urban Drainage (SuDS) principles for informal settlement upgrading. The project team developed a solution to use permeable paving to upgrade the main access route through the pilot area.
From a winding, eroded clay surface of varying width (before, left), the permeable block paved road (after, right) provided a solid, sustainable surface for vehicular and pedestrian traffic in the future. Stormwater drainage is provided on the road surface through a V-shaped cross-section. This avoids the need for stormwater pipework, which avoids the associated blockage problems in this context, and enables infiltration of stormwater.
The local municipality have expressed appreciation of this design as it enabled the road to be formalised without the need to relocate residents and remove shacks. The nature of the grass-block paving allowed for the road width to be varied according to the space available, whilst a minimum width of 3.5m was maintained.
Improved water quality, reduced river pollution: A concurrent research project conducted through the Water Research Commission (WRC) enabled the ongoing monitoring of water quality in the pilot site area. Results from this study have provided good indication of the improvement in surface water quality at a selected point within the pilot site area:
Improved service delivery - affordably: for only R15 000 per household, residents in the pilot area now benefit from a formal paved road with stormwater drainage, an appropriate system for disposal of greywater, and the area is completely free of foul smelling greywater streams. Knock-on affects will be a reduction in the number of water-borne sicknesses and trips to the clinic.
Aesthetic impacts: the Tree Gardens now provide greening of the pilot area with associated psychological benefits. The trees provide shading in hot summer months and the overall appearance of the area has resulted in residents expressing a pride for their section of the community.
Job creation: since all construction work was carried out by local labour (under supervision by Isidima), and now ongoing maintenance too, a number of employment opportunities were created for the Langrug Community.
Western Cape Premier Visits Genius of SPACE
Soon after completion in October 2016, the Western Cape Premier Helen Zille visited the project to view the progress and meet the project team. Watch below:
Video by: FLOW - for love of water
Isidima Design and Development - "Building thriving liveable cities"