Scaling up Off-Grid Sanitation

Lead Research Organisation: CRANFIELD UNIVERSITY
Department Name: School of Water, Energy and Environment


To protect human health and the environment, sanitation systems must separate people from their excreta and treat it. This does not just involve technologies but other aspects like finance, government policies and human behaviours must be considered. Sewers and wastewater treatment plants can assist in providing safe sanitation, but they are expensive and challenging to build, particularly in dense urban areas or where people do not own the land that they live on. In fact, only 45% of the world's urban population have safely managed sanitation; that is where human waste is treated before disposal. Many of these people are instead using off-grid options for sanitation, such as pit latrines and septic tanks. These are physically difficult to empty, especially in areas of high population density, on steep slopes or with a high water table, and pose significant health hazards. The collected waste is often dumped illegally, frequently into water sources. Off grid solutions can only manage waste safely if the waste collection, treatment and disposal is properly considered.

This research will focus on an emerging off-grid sanitation option in the form of container-based sanitation (CBS) across four city contexts where the provision and regulation of CBS is done by different organisations. In Cap Haitien (Haiti), CBS is provided by an NGO, in Lima (Peru) it is provided by a private company, in Cape Town (South Africa) it is provided by the municipality and in Kakuma Refugee camp (Kenya) it is provided by a private company working with an NGO. A refugee camp is included as in the future, refugees driven by climate and other factors will make up a significant proportion of the world's urban population.

Interviews will be conducted with the staff working for the CBS provider as well as other organisations that they work closely with, e.g., local government, water utilities and regulators. To capture the feelings and opinions of the people using the CBS toilets, as well as people using other off-grid sanitation options like pit latrines, a novel smartphone data collection will be used. Participants will complete a short survey several times a week to capture aspects of their mental well-being.

In addition, the data collected will reveal whether current regulations and policies support CBS and whether CBS increases disparities or decreases them. For example, does CBS without a permanent infrastructure make users feel more vulnerable to eviction, and is the collection of the containers a burden? Or does it give access to people who would not otherwise be able to use a toilet?

The project will also look at the links with other sectors, specifically waste, energy, transport and solid waste, as if CBS coverage is increased these services will be impacted. For example CBS relies on road transport and cause additional traffic. But the use of CBS stops the disposal of waste into rivers so water supplies are cleaner.

Lessons from the project will be shared with other cities who are thinking about implementing CBS, and with other sectors who are working out how they might deliver their services "off-grid". Co-I's have been identified that have expertise beyond sanitation in urban services, and results will be linked and presented at the GCRF Urban Risk Resilience Hub to look more broadly at lessons for off-grid cities.

Planned Impact

Project partners (Sanivation, X-Runner and SOIL) have shaped the research and are particularly interested in the findings. They sit alongside three other partners in the Container Based Sanitation Alliance (CBSA), who will also be engaged in the findings. The City of Cape Town made a presentation at the proposal writing workshop and have provided an informal commitment to the project.

All the universities also have MSc courses, many specifically focussing on sanitation, so the findings will be incorporated to help the next generation of sanitation practitioners consider off-grid options in projects that they will go on to work on.

Local government partners will be involved from the start of the project through workshops and bilateral meetings so that by the third year of the project they will feel confident to speak about CBS at national and international conferences. Project budget has been set aside for this purpose in each country. This is a way of ensuring their buy-in and commitment to developing these models themselves. Other local partners that will be engaged in the workshops include water utilities and regulators (environmental and financial).
Sanitation practitioners in cities that are not already implementing CBS will also be interested to see how the models can be applied and they bail be engaged through participation in sector-wide workshops and conferences. City planners who are wedded to centralised solutions will not be automatically engaged, but through careful messaging the research team will reach bout to them.

Other linked services are a particular focus of the call including water, transport, solid waste and energy, so through the research activities the project will additionally touch city planners, transport planners, energy utilities, municipalities, waste pickers and they will be invited to engage in the project in appropriate ways.
Description We investigated three separate collection strategies evaluated for their routing efficiencies as CBS goes to scale, in areas of Cape Town, Cap-Haïtien, Lima and Nairobi. The results indicate that with fewer users (e.g., 50) transfer station models offer the shortest driving routes. However, these do require users to carry their containers (e.g., up to 170 m when stations are 100 m apart).

As the number of users increases (e.g., to 5,000), visiting individual houses from a neighbourhood depot offers increasingly efficient driving distances.

Overall, however, the results suggest that economies in collection distances for scaled CBS will be largely conditional on greater vehicle capacity (rather than any particular provision strategy).

We also investigated the challenges that CBS organisations face in scaling their operations at different stages of growth, many of which are context-specific. Almost all parts of the CBS service chain are labour-intensive, with a wide variety of skills needed by that labour force. There are other resources needed as well, including waster, land and fuelled vehicles,
although these vary depending on the exact structure of the operations. Supplying cover material is an almost universal resource challenge that requires overcoming economic, technical and social barriers. Taking advantage of freely available resources can lead to CBS operators facing vulnerabilities when expanding beyond their immediate capacity. Certain growing
organisations have attempted to circumnavigate these issues by instead placing greater responsibility on their customers to source material and highlighting how this reduces the subscription fee for their service (although this can have unintended consequences such as an additional burden on vulnerable household members). Other organisations have built their service in such a way that they rely on users' familiarity with CBS enabling the adoption of other, more cost-efficient, options (although this can backfire if customers continue to be reluctant to change).

Our research has shown that the CoCT provides free, scaled up CBS to informal settlement residents and that CBS is a useful, temporary stopgap to address the lack of adequate sanitation. However, CBS does not fulfil the infrastructural citizenship expectations of residents that they have derived from political and legal promises of the post-apartheid state. Not only does it not meet infrastructural citizenship expectations, but CBS inflicts infrastructural violence when poorly serviced. This paper matters because it foregrounds the voices and experiences of CBS users, not as 'consumers' or 'clients' but as citizens of a state. The acceptance and impact of CBS is as much a political economy issue as it is a planning and engineering concern. If residents of a state believe their social contract with the state promised dignified sanitation and CBS does not meet this expectation, then no amount of technical innovation will allow CBS to fulfil the political (and practical) role of full flush sewered sanitation.

These finding has been communicated to the CBS providers so they can use it in their planning.
Exploitation Route Sanima have found it useful as they have a clearer picture of the strategies used by other enterprises, but has confirmed that their current collection strategy is the most efficient and they are instead going to see if they can find a cheaper cover material.

The planned smartphone survey will be very useful to Sanima as having a picture of their customer's perception throughout time provides valuable information that will lead to deciding on continuing or stopping activities based on how much value they add to customers. Also on the way they communicate and relate with them. There is always a gap between an intended message and how it is received, we hope the surveys will help them understand this gap. Sanergy are keen to understand the role of culture and religion in uptake of the CBS systems, which adversely affects the uptake.

MUST and UWC have been able to use the project as a catalyst to discuss the potential CBS with key decision makers. In Kenya, this created a paradigm shift on how CBS was initially viewed, promoting acceptance among the sanitation space. In Cape Town, this triggered new conversations with the city oficials about how to facilitate accountability regarding government provided off grid sanitation. It also helped them reflect on the contractors they hired.
Sectors Environment

Description Influence Kenya Sanitation Policy
Geographic Reach Africa 
Policy Influence Type Participation in a guidance/advisory committee
Impact Awaiting changes in new sanitation policy
Description Between environmental concerns and compliance: How does media messaging affect motivation and choice between disposable versus reusable facemasks?
Amount £343,974 (GBP)
Funding ID AH/W003813/1 
Organisation Arts & Humanities Research Council (AHRC) 
Sector Public
Country United Kingdom
Start 06/2021 
End 05/2022
Description Research support on Sanitation Workers: for Doctoral and Master's students
Amount $4,000 (USD)
Organisation World Health Organization (WHO) 
Sector Public
Country Global
Start 09/2021 
End 09/2022
Description The impact of Covid-19 restrictions on recreation and use of green space in Wales
Amount £10,877 (GBP)
Funding ID ES/V004077/1 
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 06/2020 
End 11/2021
Title Global ensembles of Ecosystem Service map outputs modelled at 1km resolution for water supply, recreation, carbon storage, fuelwood and forage production 
Description This data set contains Global maps of five ecosystem services using 6 different among-model ensemble approaches: the provisioning services of water supply, biomass for fuelwood and forage production, the regulating service Carbon Storage for CO2 retention and the cultural non-material service Recreation. For water, the data comes as one shapefile with polygons per watershed, each polygon containing seven ensemble estimates. The other services - recreation, carbon storage, biomass for fuelwood and forage production - come as seven tiff- maps at a 1-km2 resolution with associated world files for each tiff-map contains 43,200 x 18,600 pixels for one ensemble approach, with LZW compressed file sizes between 400MB and 950MB. For all maps, 600dpi jpg depictions are added to the supporting information with uniform colour scaling set for the median ensemble per service. Ensemble output maps were calculated with different approaches following the supporting documentation and associated publication. Uncertainty estimates for these services are included as variation among contributing model outputs and among the employed ensemble approaches. The work was completed under the 'EnsemblES - Using ensemble techniques to capture the accuracy and sensitivity of ecosystem service models' project (NE/T00391X/1) funded by the UKRI Landscape Decisions programme, with additional funding from ES/R009279/1 (MobilES) & ES/T007877/1 (RUST). 
Type Of Material Database/Collection of data 
Year Produced 2023 
Provided To Others? Yes  
Description City of Cape Town 
Organisation City of Cape Town
Country South Africa 
Sector Public 
PI Contribution Meeting with Director of Resilience for the City of Cape Town. Head: Capital Planning and Implementation, Informal Settlements Basic Services - Distribution Services Department; Water and Sanitation Directorate is attending knowledge sharing meeting in Peru.
Collaborator Contribution Attending meetings. Open minded to policy influence.
Impact Attending meetings and fieldtrips
Start Year 2020
Description FSM7 Conference presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentaion at Faecal Sludge Management conference
Year(s) Of Engagement Activity 2023
Description MUST media 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Research featured in KTN news bulletin
Year(s) Of Engagement Activity 2022
Description Talk at Sanitation Workers Forum 2021 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The role and barriers of informal pit emptiers (IPE) to achieving improved services: Mukuru, Kenya; Sanitation Workers Forum 2021: Linking Research, Policy, and Practice
Year(s) Of Engagement Activity 2021
Description Water Service Providers Association 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Plenary panelist - Water Service Providers Association, Youth and Women conference, on the topic; Capacity development and research to optimize the untapped youth and women potential
Year(s) Of Engagement Activity 2021