DAKAR:Sanitation Status
Sanitation provision in Dakar (capital of Senegal) is relatively good by comparison with most cities in sub-Saharan Africa: most households, even in lower-income districts, have a sewerage connection or a septic tank, and these systems function reasonably well at present. Significant problems are however seen in a number of districts prone to waterlogging and/or annual flooding; in these districts, faecal contamination of the local environment is likely to have major impacts on infectious disease burden (Hutton et al. 2007). This article briefly summarizes the current sanitation situation in Dakar.
This page is part of the fully editable open-access reference source on the sanitation status of all major cities in sub-Saharan Africa. The resource considers the 40 urban agglomerations in sub-Saharan Africa with a current population of 1 million or more. To read some of the other 40 country profiles, go back tothe resource Homepage.
N.B These pages should be considered as incomplete provisional drafts, and contributions are actively requested from specialists with expert local knowledge of each specific city
Table of Contents
- Background information
- Water resources and supply: overview
- Sanitation access
- Sewerage system
- Septage management (septage = nightsoil and/or sludge from onsite facilities)
- Sewage treatment (sewage = sewered wastes and/or septage)
- Sanitation in low-income districts
- Responsibility
- Sanitation masterplan?
- Sanitation financing
- Major investments and donor interventions
- Sources and further reading
- References
- Other City Profiles
Background information
Dakar is an urban agglomeration with a population of about 2.6 million people (Brinkhoff 2010). It is a flat city on a narrow-necked peninsula, with the city centre at the peninsula’s tip; some areas have permeable sandy soils, others impermeable soils. Climate is hot semi-arid (Köppen classification BSh). Flooding is frequent and severe in many districts (Wang et al. 2009). Pollutant industrial activities? There is significant horticultural activity within the agglomeration, notably in wet depressions known as niayes, and there is significant use of wastewater for irrigation (Niang et al. 2002). A large proportion of the population lives in low-income settlements (World Bank 2002), though extreme slum conditions are rare.
Water resources and supply: overview
As at 2004, Dakar’s formal water supply of about 240,000 m3/day, about 78% came from fossil aquifers below Dakar and about 22% came from the Lac de Guiers (a reservoir on the Senegal River, about 240 km to the north); the groundwater source is currently over-exploited, and the plan is to gradually increase the surface water contribution (Hoang-Gia et al. 2004a). Water supply levels are good by comparison with most African cities: as at 2002, about 76% of the population have within-plot piped supply, about 19% get water from a community standpipe, and only about 5% depend on other sources (wells, water vendors). The achievement in the 1990s of such high levels of water supply coverage, including connection of large numbers of low-income households, is widely regarded as model of good practice (see e.g. Brocklehurst & Janssens 2004).
Sanitation access
Dakar has very good sanitation status by comparison with most African cities. Official data from 2002 indicate that 30% of the population of Dakar have sewerage connections, 48% flush toilets discharging to septic tanks, 15% flush toilets discharging to cesspits (fosses étanches, i.e. non-permeable septic tanks), and 5% latrines (Hoang-Gia et al. 2004). Thus over 90% of the population uses flush toilets (mostly pour-flush), and septic tanks and cesspits are common even in households without piped water. Neither open defecation nor public latrines are widely used. Poor sanitation certainly exists, but is less common than in most African cities; in addition, in some districts flooding often leads to overflow of septic tanks on to the streets (Guy Norman, unpublished observations 2009).
Sewerage system
Dakar has an extensive and basically well-maintained sewerage network, largely built between the 1950s and 70s, extending over a large area of Dakar proper; it comprises about 742 km of pipes and 43 pumping stations (Hoang-Gia et al., 2004). This system discharges to a large activated sludge treatment plant (Cambérène). There is also a smaller sewerage network in Rufisque, discharging to a local lagoon-based plant (nominal capacity 2860 m3/day, current function reportedly poor). As at 2004, it was estimated that only about 14% of sewage collected is treated (Hoang-Gia et al., 2004); most of the rest is discharged to the sea without treatment. However, under a recent US $13m AfDB loan, the capacity of the Cambérène plant has been doubled from 9000 to 17,000 m3 per day (≈ 350,000 people), and in a second phase may be further extended to 40,000 m3 per day; there are also plans to build an additional plant (Corniche Ouest) at an estimated cost of US $47m, though as at 2010 no funding has been secured for this. The Cambérène plant functions well at present, and discharges via a long sea outfall. A recent report from the Senegalese sanitation authority (ONAS, 2009b) states that over the period 2005–2008 a total of about 28,000 connections were made to the sewerage network, and that a further 64,000 connections will be made before 2015. The unsubsidised cost-to-householder of connection to the sewerage network is high (about US $215). A recent subsidy programme financed by the World Bank provided 10,000 connections at a cost to the householder of about US $30. Furthermore, under the World Bank-financed PAQPUD project a number of settled sewerage schemes have been constructed in low-income districts, serving about 2–3000 households (Norman et al. 2009).
Septage management (septage = nightsoil and/or sludge from onsite facilities)
Septic tanks are emptied by both informal manual emptiers and private-sector tanker operators (Hoang-Gia et al. 2004). Informal manual emptiers often transfer the sludge to pits dug in the street. The PAQUD project envisaged the installation of three sludge collection points at existing wastewater treatment plants, as well as three approved locations for transfer of sludge to the sewerage network, though it appears that only one of these installations has been completed (the sludge dumping point at Cambérène) (PEPAM 2006).
Sewage treatment (sewage = sewered wastes and/or septage)
As noted above, sewerage wastewater and some tanker-transported sludge is treated at the central plant at Cambérène: this is activated sludge plant treating about 19,000 m3/day and discharging treated effluent to the sea via a long outfall. Characteristics of this plant are summarised on the ONAS website (ONAS 2010).
Sanitation in low-income districts
Low-income districts in Dakar proper include parts of Ngor, Yoff, Ouakam and Grand Médine; Grand Médine is one of the few remaining areas in central Dakar in which most households lack piped water. However, the poorest settlements are in the eastern suburbs (departements of Pikine and Rufisque), in districts including Dalifort, Medina Gounass, Guinaw Rails and Rufisque (Minvielle et al. 2005). As noted above, in many of the poorest districts of Pikine and Rufisque, the main sanitation problem is not poor toilets, but rather frequent flooding (leading to flooding of septic tanks, and pumping of septic tank contents to the local environment).
Responsibility
Progress towards the Millennium Development Goals for water and sanitation is planned and overseen by the Programme Eau Potable et Assainissement (PEPAM). In the 1990s responsibility for water supply and sanitation lay with a single entity (Société Nationale des Eaux du Senegal, SONES), but a World Bank-led reform split responsibility into three entities: SONES remained the state-owned water network asset-holder, while responsibility for water supply management was passed under a lease (affermage) agreement to a private utility with majority French ownership (Sénégalaise des Eaux, SDE), and responsibility for sanitation to the state-owned Office National de l’Assainissement du Sénégal (ONAS). ONAS is thus the asset-holder for the sewerage system, and currently does not contract out operation and maintenance. Unusually in the African context, ONAS is formally responsible for both sewerage and onsite sanitation, although in practice its day-to-day interventions in the onsite sector are limited. For detailed information on institutional aspects of sanitation management in Dakar, see Guène et al. (2003) and the excellent Wikipedia article “Water supply and sanitation in Senegal”.
Sanitation masterplan?
A major national water and sanitation strategy document has been produced, including detailed specific consideration of Dakar (Hoang-Gia et al. 2004); in addition, there is an active and well-resourced entity (PEPAM, see above) responsible for ongoing planning, coordination and evaluation of water and sanitation policy interventions.
Sanitation financing
A sanitation surcharge is applied to the water bills of all consumers in cities defined as “sewered”, regardless of whether the house is actually connected to the sewerage network.
Major investments and donor interventions
The water and sanitation sector in Senegal has received massive investments in recent decades from the World Bank and other donors including the EU, the Agence Française de Developpement, and USAID. Major projects in which the World Bank has been the primary donor and with major Dakar components include the 125m US$ “Projet EAU Long Terme” (“Long Term Water Sector Project”) (P041528), extended under the GPOBA project (“Senegal Sanitation - Supporting access to on-site sanitation services through OBA scheme in Senegal”, P102478); also the recent “Water and Sanitation Millenium Project” (P109986).
Sources and further reading
PEPAM: http://www.pepam.gouv.sn/index.php
ONAS: http://www.onas.sn/
World Bank projects: http://web.worldbank.org/WBSITE/EXTERNAL/PROJECTS/0,,menuPK:51563~pagePK:95873~piPK:95910~theSitePK:40941,00.html
References
Brinkhoff T (2010) City Population. http://www.citypopulation.de
Brocklehurst C & Janssens JG (2004) Innovative contracts, sound relationships: urban water sector reform in Senegal.
Guène O, Diop C & Trémolet S (2010) Senegal case study. In: Trémolet , Kolsky & Perez E (eds) (2010) Financing On-Site Sanitation for the Poor: A Six Country Comparative Review and Analysis. Water and Sanitation Program. http://www.wsp.org/UserFiles/file/financing_analysis.pdf
Hoang-Gia L, Thiaw AD, Toure CS, Ndir B, Toure A & Thiombane C (2004) Projet Eau à Long Terme: Elaboration d'un document de stratégie pour la réalisation à l'horizon 2015 des objectifs du milllénaire pour le développement. Volume 1: Etat des lieux. Ministère de l'agriculture et de l'hydraulique, République du Sénégal. http://www.plt.sn/Objectifs_Millenaire_PEPAM/OMD_EtatLieux_Final_oct%202004.pdf
Hutton G, Haller L & Bartram J (2007) Economic and health effects of increasing coverage of low cost household drinking-water supply and sanitation interventions to countries off-track to meet MDG target 10. Geneva, Switzerland, World Health Organization. http://www.irc.nl/page/38443
Minvielle JP, Diop A & Niang A (2005) La Pauvreté au Sénégal: Des Statistiques à la Réalité. Editions Karthala, Paris.
Niang S, Diop A, Faruqui N, Redwood M & Gaye M (2002) Reuse of untreated wastewater in market gardens in Dakar, Senegal. Urban Agriculture Magazine, December 2002. http://www.ruaf.org/sites/default/files/Reuse%20of%20Untreated%20Wastewater%20in%20Market%20Gardens.pdf
Norman G (2009) Can sewerage be pro-poor? Lessons from Dakar. Paper presented at the West Africa Regional Sanitation and Hygiene Symposium, 3-5 Nov 2009, Accra, Ghana. http://www.irc.nl/page/50808ONAS, 2009b
ONAS (2010) Station d'épuration de Cambérène. http://www.onas.sn/index.php?option=com_content&view=article&id=103&Itemid=87
PEPAM (2006) Rapport d'avancement trimestriel. http://www.pepam.gouv.sn/docs/Ravpepam_02_oct2006_fr.pdf
UNEP/GRID-Arendal (2002) Water availability in Africa. UNEP/GRID-Arendal Maps and Graphics Library. http://maps.grida.no/go/graphic/water_availability_in_africa.
Wang HG, Montoliu-Munoz M & Gueye NFD (2009) Preparing to Manage Natural Hazards and Climate Change Risks in Dakar, Senegal: A Spatial and institutional approach. Pilot Study Report. Global Facility for Disaster Reduction and Recovery. http://gfdrr.org/docs/Dakar_Report063009.pdf
World Bank (2002) Upgrading of low income urban settlements: Country Assessment Report: Senegal. http://web.mit.edu/urbanupgrading/upgrading/case-examples/overview-africa/country-assessments/download/SENEGAL.pdf
Other City Profiles
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7) BRAZZAVILLE (Republic of Congo) 3
12) DAR ES SALAAM (Tanzania) 3
14) DURBAN THEKWINI (South Africa) 3
18) JOHANNESBURG-EKURHULENI (South Africa) 3
23) KINSHASA (Democratic Republic of Congo, DRC) 3
27) LUBUMBASHI (Democratic Republic of Congo, DRC) 3
31) MBUJI-MAYI (Democratic Republic of Congo, DRC) 3
35) OUGADOUGOU (Burkina Faso) 3
36) PORT ELIZABETH (South Africa) 3
