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Sustainable Sanitation Solutions for
Refugees and displaced personsGraham Alabaster, UNHabitat
Sunday 25 August | 14.00-15.30 | Room: L12
Convenors: UNHabitat, UNHCR, SDC, EAWAG, BORDA
What are the key Issues?
• Critical decision making processes in the early phases of humanitarian
crises do not always consider longer term sustainability of sanitation
solutions.
• Many refugees and displaced communities are now accommodated in
established urban agglomerations so upgrading of host facilities could be a
priority solution
• Aside from technical choices which are fast to implement, operational costs
are often not properly considered.
• During protracted crisis situations, host governments are often saddled with
the cost of service provision, which often leads to lower levels of coverage
in host communities.
• Effective reuse of faecal sludge and wastewater is seldom prioritised. It
could be used to offset the costs of providing food to migrant communities.
Sanitation Chain
TreatmentEnd-use/
DisposalTransportEmptyingContainment
Demand
Creation
Flush ToiletSewerage network
Pumping stations
Sewage
treatment
works
End-use/
Disposal
Latrine
or
septic tank
Vacuum truckTreatment
plant End-use/
disposal
Primary
emptyingTransfer
Safely covered and replaced in new location
Promote
sanitation,
create
demand,
community
organisation
MDG focus SDG focus
Technical options
Toilet pitPumped
Emptying & Transport
Faecal sludge treatment
plant
Composting / biochar / BSFL
Container-Based UDDT
Vermi-Filter Toilet
Pour-Flush Toilet Simplified
Sewer
Vacuum Sewer
Small-Bore Sewer
InterceptorAnaerobic + Facultative
Ponds
UDDT
Showers
Maturation Pond
Constructed Wetland
Planted Drying Bed / Landfill
Biogas Toilet
Manual Emptying & Transport
Anaerobic Baffled Reactor
Understanding the Issues
S
Topography makes faecal sludge haulage
difficult
Space for waste treatment severely
restricted
Women and Girls Toilet and Shower at Home
Social challenges for Sanitation
Water availability and use dictates what
we are dealing with
• Can mitigate outbreak risk from high population density (especially water-washed disease)
• Faecal sludge → high strength wastewater
Bacteriological quality of effluent crucial
Not only to break transmission route but also impacts on reuse of effluents
Direct disposal of FS into open drains
Solid waste drainage and sanitation are inextricably linked
Sanitation Masterplan
• Multi-year investment plan for sanitation
• Agreed technology and management models
• Economic - lowest long term operation cost
• Environmental – protection of environment, fit within limited space,
• Socially acceptable, reduce public health risks, wastewater reuse,
• Household/Family Latrines and Bathrooms where possible
• Integrated planning of SWM, sullage & drainage
• Different solutions for different sites-Centralised, semi-centralized, decentralized
Master Planning
Approach
Effluent has to drain
somewhere
Can’t rely on leach pits –
use natural drainage
network
Hence need to treat to
good bacteriological
standard
Availability of space for treatment
More opportunity for nearby wastewater treatment
Limited space for nearby wastewater treatment
Intermediate case
In most locations, tertiary treatment to reduce pathogens to acceptable levels with be limited
Waste-Stabilisation Ponds
Facult.Pond
Facult.Pond
A
A
• Simple to operate• Robust• Reflect current
practices
Decentralised Treatment: e.g. ABR
Operational performance data for ABRs in this region?
Low footprint, but in tight spaces conveyance to tertiary treatment site required
Simplified Sewerage
Definition/General Framework▪ constructed with smaller diameter pipes, ▪ laid at shallower depths, ▪ flatter gradients and fewer manholes/inspection chambers than conventional
sewers, ▪ less conservative design standards than conventional sewers, ▪ allows for more flexible design at lower costs, ▪ retrofitted to conventional sewer network.Transferability/Replicability▪ dense urban areas where space for on-site technologies or conventional sewer
is limited ▪ design can also be adapted to the conditions with steep gradients ofrocky hilly areas▪ existing unplanned low-income, less accessible areas i.e. Mwanza’s rocky hills. ▪ Pipes are usually laid within▪ property boundaries and along narrow trails rather than beneath roads▪ allows for fewer, shorter and cheaper pipes (no heavy load)Two important adoptions:1. due to the steepness of Mwanza’s informal settlements, the gradient of the
sewer increased from 10 to 30 per cent.2. due to the presence of rock outcrops, most of the pipes are run above ground
rather than being buried.
Simplified Sewerage – DesignAngular pipe alignment to reduce the pressure flow of sewage
Simplified Sewerage – DesignSewer pipes concrete covered to avoid vandalism and exposure to heat
Simplified Sewerage – DesignHigh-density polyethylene (HDPE) pipes were used for main and lateral sewers; thus, any change
of direction and/or angle was made easy by electrofusion jointing (connection)sewage
Simplified Sewerage – DesignMain Simplified sewer line connected to Conventional Sewer system
SANITATION
City/Town % Coverage Before % Coverage After Total Beneficiaries
MWANZA Schools 0 34 157
(26 schools, 680 Teachers)
Public Places 0 620
(1 Dispensary , 1 Market)
INFORMAL AREAS Kilimahewa 0 14.5 (117 *9) = 1 053
Unguja 19.6 (178*9) = 1 602
Kwimba 21.7 (123*9 ) = 1 107
Total 3 762
WATER
Mwanza (Informal Areas) Kilimahewa, Unguja 0 14.4 (117+131 *9) 2 232
Mwanza 90 95 186 967
Magu 32 90 45 000
Misungwi 50 90 30 000
Lamadi 10 90 23 000
Staircases (Kilimahewa-Kwimba-Unguja) 0 18.3 3 762 +
3. Outcomes/Impact
*9 = Average number of persons per structure in Mwanza informal areas, (UN-Habitat 2019)
Simplified Sewerage – Impact▪ Increased access to basic sanitation
▪ Increased access to safe piped water
▪ Improved wastewater collection
▪ Increased number of households with flush toilets compatiblewith SS
▪ Improved Walkability
▪ Increased demand for sanitation services
▪ Improved community knowledge on WASH
▪ Improved WASH behaviours
▪ Reduction in pollution
▪ Increased Citizens participation in WASH programmes
A new paradigm for low-cost urban water supplies and sanitation in developing countries
• A “new paradigm” is proposed for low-cost urban water supply and sanitation, as follows: water supply and sanitation provision in urban areas and large villages should be to groups of households, not to individual households.
• Groups of households would form water and sanitation cooperatives. There would be standpipe and yard-tap cooperatives served by community-managed sanitation blocks, on-site sanitation systems or condominialsewerage, depending on space availability and costs and, for non-poor households, in-house multiple-tap cooperatives served by condominial sewerage or, in low-density areas, by septic tanks with on-site effluent disposal.
• Very poor households (those unable to afford to form standpipe cooperatives) would be served by community-managed standpipes and sanitation blocks.
• Mara D.D & Alabaster G.P, Water Policy 10 (2008) 119–129 “A new paradigm for low-cost urban water supplies and sanitation in developing countries”
Community-based Infrastructure-led planning
Kibera Integrated Water & Sanitation Project
Background information on Kibera
• 7 Km Southwest of the city of Nairobi, within the city boundaries. 3.5 by 1.5 km, 250ha with densities > 2,000 / Ha. 13 Villages 500,000 to 700,000 inhabitants
• No formal road network directly hinders, economic development of the area
• Most lack access to clean water and sanitation facilities
• kiosks and stand pipes are the major sources of water
Background information on Kibera
• The pipelines are usually ruptured exposing water to contamination
• Pit latrines main form of sanitation these toilet facilities are commercialized and expensive
• No waste collection services poor access roads prohibits waste collection Waste gets swept into drains which empty into Nairobi Dam
Kibera Integrated Water & Sanitation Project
• 7 sanitation facilities now accessible to
21,000 residents of Soweto East
(showers and toilets) cost US $ 8 per
capita) Each Facility Management
Group collects on average – Kshs
46,800 (US $ 600) per month
• Construction of the 1.5 km tarmac ring
road across Soweto East completed,
600m of improved drains constructed
• The youth-organized door to door
garbage collection for 400 homesteads
• Waste recycling has become a source
of income with the youth recycling
waste paper for resale
Conclusions
• An early assessment of conditions is critical to identify the best technical options
• Great opportunities exist to look at networked options at an early stage
• A thorough evaluation of CAPEX and OPEX needed
• Treatment must consider bacteriological quality
• Longer term options for reuse should be evaluated
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