What do you understand by the term Sanitation? Its use is often vague with multiple meanings. In Tanzania, the 2004 National Environmental Health and Sanitation Policy Guidelines used a broad definition of sanitation which included water supply, food, waste management, control of chemicals, environmental pollution, human settlements, prevention and control of communicable diseases, HIV/AIDS, vector and vermin control, occupational health and safety, mining and quarrying, port health and disposal of the dead etc; a total of 25 categories. Clearly not everyone is interested equally in every aspect of “sanitation” so where does your interest lie ? If the answer is safe excreta disposal then why not call it ‘safe excreta disposal’?

The terms sewage, sewerage, wastewater treatment, and sanitation are often used in an inter-changeable manner. Again there is a need to be specific and to limit ambiguity by using precise terminology. If you intend to build some form of piped sewer systems call it a sewerage project, if you intend promoting latrine construction and use then call it on-site technologies.

The viability of different excreta disposal approaches depends on housing density, housing arrangements (types and patterns of occupancy), land ownership, plot layouts and local hydrogeology. Systems that provide sustainable solutions in low density rural areas of owner-occupied housing, will not work in high density unplanned urban areas dominated by squatter housing.

In summary, by being specific with regard to objectives, technology and target populations, basic problems become more manageable and the solutions more apparent and less daunting. A project title such as ‘Safe excreta disposal using low cost sanitation technologies in high density unplanned areas’ focuses on a specific series of issues, whereas “city wide sanitation” leaves project implementers wondering where to start.

By being specific, the demarcation of roles, responsibilities, and boundaries between the different government bodies also becomes more apparent and the process of de-fragmenting the un-coordinated sanitation sector can begin.

What do you mean by sustainable?

The term ‘sustainable’ also suffers from being too vague for practical use. It is perhaps better to consider sustainability in excreta disposal as occurring at three different levels

• Sustainable household excreta disposal, which focuses on the design of the latrine and the ability of the family to reuse and/or continue using the latrine once it has been built.

• Sustainable community excreta disposal, which focuses on the ability of the community to maintain latrine coverage at (or close to) 100% so as to not prevent any risk to public health.
• Sustainable national excreta disposal, which ensures that financing and policy environment allows all communities to maintain safe excreta disposal

Projects tend to concentrate on latrine design and household sustainability. With the short term and transient nature of many sanitation projects, they should perhaps be concentrating on achieving community sustainability. Latrine design is an important element of community excreta disposal, but it is far from being the only element.

As an overall summary, sustainable excreta disposal can only be said to be achieved when:

• latrines are being used consistently by all members of the family
• the community / society is maintaining latrine coverage at 100% without external support
• there is no significant risk to community health from disposal techniques
• there is no significant degradation of the environment
• it can be maintained over a prolonged period i.e. 20 years

Consistent use

To have an impact on public health, latrines have to be used at all times by all members of the family. This is more difficult to achieve than it may at first appear. Children are often scared of the monsters their brothers have told them live in the dark pit latrines; latrines can harbour snakes making use dangerous in the dark and latrines sited a distance from the house are inconvenient, particularly at night when open defecation nearer home is an easier option. Communal latrines which are locked after dark, or unused because of fear of attack. They do not allow for consistent use either and are often not designed for use by children.

Maintaining coverage at 100% without external support

Villages and communities grow, either by increasing the area they occupy or their density. Populations can double in size within 10 years and a project achieving 100% latrine coverage in 1995 may have dropped to 50% coverage by 2005. Any system developed for building latrines needs to be able to continue building and repairing them after external funding has ended. The system should also ensure that community members do not become dependent on subsides or outside organisations to achieve this.

No significant risk to community health from disposal techniques

The desired health impacts of latrine use are quickly lost if using the latrine results in pathogens entering into the community.
This can occur in a high density urban setting by:
• faecal contaminants entering into the water supply via the ground water
• not using a pit emptying service and letting the pit contents flow into
• the street
• a surface drain
• a neighbours’ compounds

No significant degradation of the environment

There is a growing concern about the impact latrine building has on the environment. Designs that require the use of local bricks which need firewood to make, will have an environmental impact. Traditional latrine manufacture has seen local adaptations such as the use of slow growing hard woods, to support the platform.

Can be maintained over a prolonged period i.e. 20 years

Any delivery system that is developed has to meet the needs of households who are slow to adopt latrine usage and change their behaviour. The slowest tend to be the poorest, least educated and most risk averse members of the community. The delivery system itself must be financially sustainable, be locally available and meet evolving needs over time.

There has been debate within the sector about widening the definition of sustainable sanitation to include waste reuse. The principle being that waste should be considered a resource and that sustainable sanitation is only achieved when the nutrients in waste are returned to the land. It is argued that the western style of waste treatment, where nutrients eventually end up as pollution in the world’s rivers and oceans is globally unsustainable. This has resulted in the promotion of ecological sanitation which is based on composting human waste and using it as fertilizer. This is a persuasive argument in the right context. If a community is predominantly agriculture based, soil fertility is declining and the cost of artificial fertilizer is increasing. The adoption of ecological sanitation is rational and can have a large impact on the household economy (D’Souza 2005).

Achieving these five criteria is not an easy process and cannot be done by using a one-off, technically-led, supply-driven, hardware-based approach. It requires long term commitment and sustained management from the public bodies responsible for public health but they cannot do this alone. Effective partnerships with private sector latrine builders/service providers are needed. Just as curative health is not considered to have been improved by the provision of a hospital; excreta disposal and the associated public health benefits cannot be considered to have been achieved with the simple provision of latrines.