Official statistics suggest that about 2.6 billion people do not have access to “improved” sanitation. 75% live in Asia, 18% live in Africa and 5% live in Latin America and the Caribbean.

The CBS framework is tailored to improve sanitation conditions in densely populated urban areas. Project implementations depend on the active cooperation of communities, governments, NGOs, and the private sector. Implementation of smart and proven technical options are synthesized with capacity building measures and technical expertise to mainstream Community-Based Sanitation (CBS) as a viable technical option in areas, where neither individual on-site systems nor centralized sewerage systems can fulfil the need of stakeholders for basic sanitation.

Increased urbanisation and industrialization has reduced quality of livelihoods significantly for millions of people who live in low-income settlements within cities. Lack of basic sanitation infrastructure endangers public health and natural resources, resulting in enormous losses of lives and public/private funds.
Recently published data suggests that improved sanitation reduces diarrhoea morbidity by 32% on average.A report by the Asian development Bank (ADB) estimates the economic losses through inadequate sanitation and sewage treatment for Indonesia to be 4.7 billions $ per year. Besides improving livelihoods and the environment, provision of sanitation
facilities would substantially benefit national economies.

Transmission pathways of faecal-oral diseases
Source: Prüss et.al. 2002

New infrastructure development projects usually provide sanitation services to up to 60-70% of the urban population, residing in strategic residential areas, whereas CBS schemes aim to improve health and environment of communities in densely populated areas with low income, usually located in inner-city areas or at the fringe of industrialized zones.
The CBS approach is an alternative option that fills the significant „gap" between inappropriate on-site sanitation (e.g. absorption pits) and the shortcomings of expensive conventional centralized sewerage collection and treatment systems.
Within CBS communities find their own informed demand, are given education about the connection between sanitation, hygiene and diseases and are encouraged to organize the operation and maintenance of sanitation infrastructure.
CBS projects are highly demand responsive and rely on active participation as well as contributions from target communities and municipalities. Specific mechanisms have been developed for planning and budgeting in order to make CBS compatible with administrative requirements of governments. According to requirements and abilities, sanitation is planned, designed and constructed for and together with the community.

Demand-Responsive Approach (DRA)
CBS initiatives and partnerships are established in regions where stakeholders on different levels are willing to promote, finance and manage CBS infrastructure. Participating communities should be free of conflict between residents.
- Participatory Planning: Participatory project planning must achieve equity within community regarding access to new sanitation infrastructure.
- Informed Choice: Sustainable CBS systems reflect the preferences of stakeholders.

Through the Informed Choice approach, communities and municipalities are informed about benefits and disadvantages of different options before decisions are made.
- Professional Design and Workmanship: Functioning and long-lasting sanitation infrastructure depend on professional technical designs and high-quality craftsmanship.
- Operation and Maintenance: Costs for operation and maintenance of sanitation infrastructure should be fully covered by communities/users.

Selection of CBS-systems and its components, depend on existing requirements and capacities of implementing communities. Basic CBS system consists of a toilet component, a collection component, a treatment component and a disposal/ reuse component. The main CBS-components are shown in the selection-tree below.

Selection Criteria for Technical Options

Capacity: Are components suitable for individual households and/or neighbourhoods with up
to 1000 inhabitants?
Costs: Are anticipated investments and costs for operation and maintenance compatible with existing financial resources?
Self-help compatibility: Can communities effectively assist during construction and implementation? During which phases of implementation is expert staff required?
Operation & Maintenance: Can routine operation and maintenance activities be carried out by members of the community or is expert help required?
Replication potential: Can sanitation experts of municipalities replicate/disseminate preferred technical options independently?
Reliability: Can a problem-free functioning and operation of technical options be guaranteed?
Convenience: How far do technical options match preferences of communities regarding „convenience"?
Treatment Efficiency: What environmental discharge standards must be met?

When municipalities want to mainstream CBS and Decentralized Wastewater Treatment Systems

Municipalities embarking on disseminating Community Based Sanitation must be aware of the fact that appropriate disposal of sludgesaccumulated in small-scale wastewater treatment systems needs to be carried out at intervals of one to two years.