Simplified sewage system in Mji Mpya, Vingunguti


Prepared by: Selamawit Wondimu Robi, ACRC database team (link )

Contributors: Tim Ndezi, Centre for Community Initiatives (CCI) (link )

Published: 05 March 2024

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Key information

Main city: Dar Es Salaam, Tanzania.

Scope: Sub-city level

Lead organisations: Centre for Community Initiatives (CCI)

Timeframe: 2014 – 2019. A second phase, involving different funder and partner agencies was from 2019 to 2022.

Themes: Informal settlements; Informality; Infrastructure; Innovation; Planning and design; Water and sanitation

Target population: Households: 1,200. Individuals: 7,200.

Financing:

Funding sources: The UK Foreign, Commonwealth and Development Office (FCDO) funded the Orangi knowledge exchange and simplified sanitation system implementation, through IIED and SDI involvement in the SHARE research consortium. Through the Tanzania Urban Poor Fund, CCI administered 122 loans of TZS 200,000–700,000 (USD 80–280) to Mji Mpya landlords to improve toilets inside their multiple-occupancy plots, once these had been connected to the SSS.

Approaches used in initiative design and implementation:

  • Community organisation.
  • Context specific planning.
  • In situ informal settlement upgrading.
  • Knowledge exchange.
  • Public-Private-NGO-Academic coalition.

Local Area: Mji Mpya

Area type: Informal settlement

Level 1 administrative unit: Dar es Salaam

Level 2 administrative unit: Ilala District

Level 3 administrative unit: Vingunguti Ward

Initiative description

Background and context

Dar es Salaam is one of Africa’s fastest growing cities, with an annual growth rate of 4.7% and a population of 5.5 million that is expected to double over the next ten years. Over 70% of the city’s population is currently living in informal settlements, while only 10% of the city’s population has access to the formal sewerage network. Pit latrines, which are often overfilled or exposed to illegal disposal, are the predominant form of sewerage provision (over 80%) in the city. While the Dar es Salaam Water Supply and Sanitation Authority (DAWASA) is responsible for the city’s formal sanitation provisions, a range of local actors (including private vendors and NGOs) provide the informal systems that cover most of the city’s sanitation provision.

This case study documents one such informal sanitation system provision initiative carried out in Mji Mpya – an informal settlement located close to the city centre with a population of around 17,000 people, the majority of whom are tenants. The settlement is located on a hillside, with more prosperous residents living further up the hill and the lowest-income residents living at the bottom of the hill and next to a river. Before the simplified sanitation system (SSS) initiative was developed, most residents used pit latrines that presented various challenges. These included high cost of maintenance; poor conditions; conflict over access; limited access for the elderly, disabled and children; prone to smell; and the prevalence of mosquitoes, cockroaches and flies.

Simplified sewerage is an approach to providing low-cost systems for cities that has been applied in informal settlements across the world. It is generally understood to be a lower cost option for sewering cities, because it involves: “sewerage networks that use smaller diameter pipes, laid at a shallower depth and with a flatter gradient than conventional sewers, allowing for lower costs and greater flexibility in the system’s design. While SSS designs vary, a key difference with conventional sewerage is that the pipes are laid between multiple-occupancy compounds and under footpaths rather than under roads. This means that they do not need to be load bearing and so can be made of less robust materials like plastics. SSS removes waste as conventional gravity systems do; however, the flexible design standards allow for systems to be adapted to the local topography and built environment. In addition to savings on materials and installation, the SSS pipes can be accessed, repaired, and extended more easily than conventional sewers. SSS provides an improvement on commonplace pit latrines, which are costly to empty and can overflow, particularly during rainy seasons. Typically, SSS includes installing toilets as well as sewerage” (Yap et al., 2023:3).

Summary of initiative

The Mji Mpya simplified sanitation system initiative emerged from partnerships established under the 2010–18 Sanitation and Hygiene Applied Research for Equity (SHARE) research consortium, which was funded by the UK Department for International Development (now known as FCDO) and led by the London School of Hygiene and Tropical Medicine. SHARE’s partner organisations included the International Institute for Environment and Development (IIED) and Slum Dwellers International (SDI), among others.

Working in partnership with the Centre for Community Initiatives (CCI) and the Tanzania Urban Poor Federation (TUPF) – together the SDI affiliate in Tanzania – the aim was to test the replicability of SSS technology in Dar es Salaam. Through a process of knowledge exchange with technical staff from the Orangi Pilot Programme in Karachi, Pakistan, a first phase of SSS was designed and installed in Mji Mpya over a five-year period from 2014 to 2019. This first phase forms the basis of this ACRC urban reform case study. A second 2019–22 phase is mentioned below, under scaling up and replication.

The SSS was comprised of nine routes that went through the settlement and connected 300 multiple-occupancy compounds, each of which has an average of four households. It used PVC class B pipes, buried in shallow trenches and laid at a gentle slope, that drained into a sewerage treatment pond managed by DAWASA.

The initiative targeted the lower-income majority in the informal settlement, who were most affected by expensive pit latrine maintenance costs, in comparison to which the less costly maintenance of SSS systems benefits residents. The initiative has enabled a majority of its beneficiaries to reduce household expenditure on health, thereby increasing their capacity to save income. Due to reduction in the amount of waste disposed of in the settlement, residents have linked the SSS with a reduction of epidemics such as cholera and decreased conflict within the settlement.

Property owners and landlords – who in Mji Mpya are a mix of residents and absentee landlords – were also given the opportunity to take out loans of TZS 200,000–700,000 (USD 80–280) to improve toilets inside their compounds, once these had been connected to the SSS. These loans were administered by CCI through the TUPF. CCI also trained a community construction team of residents to install the toilets, as well as training over 100 community sanitation technicians, many of whom were women.

The Mji Mpya case also illustrates the importance of community inclusion in the design and delivery of initiatives to improve their settlements.

Target population, communities, constituents or "beneficiaries"

Three hundred multiple-occupancy plots were connected to the SSS, each containing an average of four households with an average of six people (totalling around 1,200 households or 7,200 people). In addition, 122 landlords were given loans of between TZS 200,000 and 700,000 (USD 80–280) to improve the toilets inside their multiple-occupancy plots.

ACRC themes

The following ACRC domains are relevant (links to ACRC domain pages):

Informal settlements: SSS initiatives are widely understood to be part of informal settlement upgrading, where lower-cost SSS are a more feasible alternative to conventional sewerage systems. The ACRC conceptual framework recognises the role played by informal settlement upgrading such as in Mji Mpya – not only for creating access to better services that improve residents’ health, incomes and wellbeing, but also for creating and strengthening resident associations and reform coalitions and enhancing their bargaining power. This is illustrated in the Mji Mpya case, where new SDI federation savings groups were formed that engaged with local authorities and civil society agencies to successfully upgrade an informal settlement.

Housing: SSS initiatives are closely related to the domain of adequate housing provision, as access to sanitation is one of the key indicators of adequate housing provision. ACRC’s conceptualisation of the housing domain recognises that the cost, availability and suitability of housing options are influenced by multiple formal and informal systems, including bulk infrastructure connections like sanitation systems and connections. Mji Mpya is a case that shows how living conditions and adequacy of housing are affected by the improvement of sanitation systems.

Health, wellbeing and nutrition: Finally, SSS initiatives are key to the health, wellbeing and nutrition domain, as access to safe water and sanitation would address at least 10% of global health concerns (WHO 2012). Poor access to clean water and sanitation, together with malnutrition, have made many urban residents – especially those living in informal settlements – vulnerable to communicable diseases, such as malaria and tuberculosis. The Mji Mpya case illustrates how improving sanitation infrastructures helps reduce health risks and improves overall wellbeing.

The following ACRC crosscutting themes are also relevant (links to ACRC domain pages):

Climate change

The SSS initiative in Mji Mpya aimed to address problems in the settlement related to flooding that have been made worse by both inadequate sanitation and the increasing impacts of climate change in the area. “Since 1998 [Mji Mpya] had experienced increasing flood incidents and this can be associated with processes of urbanization and consolidation, particularly in the lower lying areas near the river and around the ponds. The impacts of flooding were worsened by improper drainage, inadequate sanitation and deficiencies in the solid waste management” (Hofmann et al., 2023).

What has been learnt?

Effectiveness/success

The goal of the Mji Mpya SSS initiative was to replicate the success story of the Orangi Pilot Programme (OPP) that had been successful in providing an affordable alternative to expensive conventional sewerage systems in Orangi Town, one of the lowest-income areas of Karachi, Pakistan.

The OPP had developed an “internal/external” model with four levels: (1) structure, compound or plot; (2) sewer in the lane; (3) neighbourhood collector sewer; and (4) trunk sewer and treatment plant (Yap et al, 2023). The first three levels were managed by residents. The fourth, given its associated cost and labour, was managed by the state. By 2011, 90% of Orangi’s sewer lines had been constructed and financed by residents, improving public health and fostering community organisation (ibid).

The Mji Mpya SSS initiative wanted to replicate this model of shared responsibility and financing between communities and the local state that could facilitate the rapid construction of sewer lines in low-income settlements like Mji Mpya.

The OPP demonstrated that partnerships between NGOs, residents and local state actors can deliver successful SSS models. Mji Mpya SSS wanted to replicate the composition and successes of the OPP public–private–NGO urban reform coalition.

Understanding of success in the Mji Mpya SSS initiative overlaps in particular with three of ACRC’s five catalysts of urban reform:

Organised citizens: Through the support of CCI, residents organised and negotiated sanitation tariffs with DAWASA. They were also actively involved in identifying the routes of the sewage lines and took on responsibility for maintaining the toilet in the compound, the sewer in the lane and the neighbourhood collector sewer. CCI organised all participants of the project: the Mji Mpya community, federation savings groups (linked to TUPF), ward officials, municipal officials and governmental agencies (DAWASA and the Energy and Water Regulatory Authority (EWURA)). The Tanzanian Urban Poor Federation (TUPF) played a central role in organising the community. The SSS has eight networks, and TUPF ensured that in every network connecting to the SSS, a savings group was formed and that these new groups involved both landlords and tenants. During the meetings, landlords were involved in decisions on the use of land spaces for pipe installation.

Reform coalitions: The project demonstrates how partnerships between NGOs, residents and local state actors can deliver successful SSS models, as seen before in the Orangi Pilot Project. The case demonstrates the role that NGOs and other actors can play in supporting community-managed urban sanitation in low-income, mixed-tenure contexts – but points to the need for ongoing engagement between all parties.

Coproduced project design: The design and installation of SSS in Mji Mpya, which took place in phases between 2014 and 2019, involved CCI and SHARE programme partners (SDI and IIED) as well as technical assistance from Ardhi University and Cambridge Development Initiative. The network routes were identified by residents.

Based on community assessments – surveys and focus group discussions – conducted by CCI in collaboration with academics, the Mji Mpya SSS initiative “has had positive social, economic, and environmental impacts. The social impacts were identified at both household and settlement level, although the generally positive economic impacts were unevenly distributed within both the settlement and households” (Yap et al., 2023: 26). The initiative was also found to be successful in creating strong partnerships between NGOs, residents and local state actors.

Previous research has identified a number of issues highlighted by different groups and which have been addressed by the initiative. For example, the landlords have reported that the SSS had solved a core challenge they faced, which was the cost of emptying toilets – allowing them to redirect the money to cover other household expenses. Another success the landlords identified was a reduction in disputes between neighbours arising out of grievances over wastewater incursions. (Landlords in Mji Mpya are a mix of residents and absentee landlords.) Tenants have reported that a notable improvement arising from the SSS implementation has been the alleviation of conflicts between tenants and landlords over toilet improvements. Tenants had previously struggled with landlords that were not ready to improve the toilets, affecting tenant–landlord relationships.

Understanding limitations

The project covered only a part of the settlement, not a whole settlement, thus leaving a huge demand for sanitation improvement in the rest of the settlement. This has in part been addressed in the second 2019–22 phase of the SSS implementation (see scaling-up section below).

The main challenge of the project was maintaining ongoing engagement between all parties involved. This is a challenge in many SSS initiatives around the world, where maintaining longstanding and productive relationships with enabling actors is difficult for a range of reasons – including the absence of a capable civil society sector and the lack of social capital within settlements, both often determined by how new a settlement might be. In the case of Mji Mpya, strong partnerships initially anchored by personal relationships were later threatened by staff turnover. Addressing underlying issues like these is critical to addressing the challenge of maintaining productive engagement within urban reform coalitions.

Another key challenge has been the unequal distribution of costs amongst residents where potential cost inequalities were not addressed in initial plans. Addressing the unequal distribution of costs involves the development of simple regulations across homes that protect tenants from the risks in landlord-designed contracts and takes into consideration groups that require subsidies in the design of tariffs and other utility bills. These groups include large families and the lowest-income tenants.

One example is the utility’s approach to setting tariffs: DAWASA had initially developed tariff setting for sewerage which was high and did not take into consideration what was affordable to low-income communities in the area. A consultative process was necessary, between the Energy and Water Utilities Regulatory Authority (EWURA), DAWASA, community and federation groups, through which the tariff was reduced by one third to a level the community could accept (from TZS 7,500 to TZS 5,000/month).

Increased rents and displacement of the lowest-income tenants as a result of improved sanitation is a further limitation. The SSS initiative helped improve living conditions within the settlement. As a result, some landlords who had improved their toilets increased the rents for rooms in their compounds. While this brought increased income to landlords, it leaves the settlement’s poorest households with fewer affordable shelter options. Those that are affordable are cheaper because there are fewer services provisions, such as water, improved sanitation and electricity.

Repayment of the landlord toilet loans has also been a challenge. Although122 loans were administered between 2015­ and 2016, only half have been fully repaid and with many defaulters. Lack of enforcement of loan repayment schedules has been a contributing factor, leading some landlords to assume the loans were effectively grants. Lessons learnt have been taken into the next phase, where CCI has allowed more time to mobilise communities and community resources for improving toilets before connections to the simplified sewerage were carried out — demonstrating a demand-driven rather than supply-driven approach that has proven more effective (see below).

Potential for scaling and replicating

In Mji Mpya, a second SSS phase from 2019 to 2022 has continued efforts to improve sanitation throughout the informal settlement, by targeting the structures that could not be connected during the first phase because their location prohibited drainage to the existing DEWASA-run stabilisation pond. The second phase was funded by SwedBio (Stockholm Resilience Centre) and implemented in partnership with KDI (Koukey Design Initiative). It involved implementation of both a piped network and a decentralised wastewater treatment system (DEWATS), designed according to principles of “nature-based solutions” and managed by a community-based committee. Because of problems with defaulters in the first phase, loans were not offered in the second phase; instead, residents and landlords were encouraged to use their savings for toilet improvements.

In Dar es Salaam, there is potential to scale up SSS initiatives in other informal settlements in the city and CCI has been exploring options with local state actors for implementing the community-led and managed processes described here. However, the core challenge of maintaining longstanding productive engagement in reform coalitions has also been an issue in efforts to scale up the initiative in other low-income settings in the city. Nevertheless, the Mji Mpya SSS community coalition has continued to share experiences and engage in knowledge exchange – for example, with other national SDI federations during regular SDI affiliate gatherings and other strategic planning meetings. In addition, a learning exchange was facilitated by SDI, in which the Kenyan SDI federation travelled to Dar es Salaam to learn from the Mji Mpya SSS implementation and its successes and challenges.

Before Mji Mpya, SSS initiatives had already been successfully implemented in many parts of the world, including Soweto, South Africa (Manga et al., 2020); Orangi Town, Karachi, Pakistan (Hasan, 2020; Hasan, 2007); San Salvador, El Salvador (Satterthwaite et al., 2019); Brasilia, Brazil (Melo, 2005); and Mumbai, India (McGranahan and Mitlin, 2016).

Participating agencies

Name
Type
Role in Initiative
NGO affiliated to SDI
Lead organisation; Implementation
Academic/Research
Data collection; Technical support
NGO
Implementation; Technical support
Government utility (Local)
Infrastructure provision; Technical support
Academic/research
Partner
Network of community-based organisations of the urban poor
Knowledge exchange facilitation; Partner
Grassroots social movement
Community coordination
Development cooperation
Funder

Further information

Further resources

References

Hasan, A (2007). “The Sanitation Program of the Orangi Pilot Project – Research and Training Institute, Karachi, Pakistan”, in AM Garland, M Massoumi and BA Ruble (eds), Global Urban Poverty: Setting the Agenda. Washington, DC: Woodrow Wilson International Center for Scholars, pages 117–150.

Hasan, A (2020). “What has emerged from 30 years of the Orangi Pilot Project?”, in DV McQueen (ed), Oxford Research Encyclopaedia of Global Public Health. Oxford: Oxford University Press.

Hofmann, P, Ndezi, T and Makoba Dominick, F (2023). “Coproduced pathways towards service provision equality: The case of simplified sewerage in Mji Mpya, Dar es Salaam”. KNOW Working Paper Series No.9. London: Knowledge in Action for Urban Equality, UCL.

Manga, M, Bartram, J and Evans, BE (2020). “Economic cost analysis of low-cost sanitation technology options in informal settlement areas (case study: Soweto, Johannesburg)”. International Journal of Hygiene and Environmental Health 223(1): 289–298.

Melo, JC (2005). The Experience of Condominial Water and Sewerage Systems in Brazil: Case Studies from Brasilia, Salvador and Parauapebas. Washington, DC: World Bank Group.

McGranahan, G, & Mitlin, D (2016). “Learning from sustained success: how community-driven initiatives to improve urban sanitation can meet the challenges”. World Development 87: 307–317.

Satterthwaite, D, Beard,VA, Mitlin, D and Du, J (2019). Untreated and Unsafe: Solving the Urban Sanitation Crisis in the Global South. Washington, DC: World Resources Institute.

World Health Organization (2012). Global costs and benefits of drinking water supply and sanitation interventions to reach the MDG target and universal coverage. Geneva: World Health Organization (WHO).

Yap, C, Mcfarlane, C, Ndezi, T and Makoba, FD (2023). “Sanitation challenges in Dar es Salaam: The potential of Simplified Sewerage Systems”. Environment and Urbanization 35(1): 12–29.

Cite this case study as:

Robi, S.W. (2024). “Simplified sewage system in Mji Mpya, Vingunguti”. ACRC Urban Reform Database Case Study. Manchester: African Cities Research Consortium, The University of Manchester. Available online.


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