UNDP | Environment & Energy

Ecological Sanitation

UNDP has considerable expertise in the area of Ecological Sanitation:

Ecological sanitation is an approach to human excreta disposal that aims at recycling nutrients back into the environment and into productive systems. UNDP has launched a project to further develop this concept and increase its application. The project is financed by the Swedish Agency for International Development Cooperation, SIDA.

About three billion people today lack safe sanitation. Within 20 years it is expected that an additional two billion will live in towns and cities, mainly in developing countries, demanding sanitation. The need for action is urgent, but do we have the solutions?

Conventional sewage systems, based on flush-toilets, have failed to solve the sanitation needs for developing countries. Over 95% of sewage in developing countries is today discharged untreated, polluting rivers, lakes and coastal areas. The water-based sewage systems were designed and built on the premises that human excreta are a waste suitable only for disposal and that the environment is capable of assimilating this waste.

The other conventional sanitation solution for poor people in developing countries, the pit latrine, also has shortcomings especially in densely populated areas where space is limited. Groundwater is almost inevitably polluted thus threatening drinking water supply.

These systems contribute to many of the problems faced by society today: water pollution, scarcity of freshwater, destruction and loss of soil fertility, and food insecurity.

Moreover, in agricultural research, the continuing decline in soil fertility is of growing concern. More and more researchers claim that presently applied farming methods are not sustainable. What we have today is a linear and massive flow of nutrients from rural areas to the cities in the form of agricultural products. By failing to return natural fertilizer to the land we are depleting soils of nutrients and ultimately diminishing food supply. For food security and agricultural purposes there is a need to utilize the valuable nutrients in human excreta.

Sanitation needs to be rethought as human excreta contain valuable resources. As a matter of fact the nitrogen, phosphorus and potassium each of us produces each year is enough to produce wheat and maize for one person. The health aspects must be maintained but human excreta can be made safe through controlled biological processes. There is a need for an eco-systems approach to sanitation where resources are reused and recycled - ecological sanitation.

Reuse of human excreta has been the norm in most cultures and societies till recently (Europe, Japan) and is widely applied in rural communities in China and Vietnam and in urban areas in Yemen. Today we see a promising development where traditional sanitation methods (decomposition, dehydration) are modified to suit today's needs and requirements. The City of Stockholm has supported the introduction of ecological sanitation in middle-class housing areas, where the urine is centrally collected, stored and spread on farmland as fertilizer. In Mexico, China and El Salvador the method is applied in densely populated urban areas. Research and development takes place in countries such as Vietnam, India, Ethiopia, Zimbabwe and Bolivia through support from SIDA.

Ecological sanitation is based on the following principles:

Prevent disease
- must be capable of destroying or isolating faecal pathogens;

Protect the environment
- must prevent pollution and conserve valuable water resources;

Return nutrients
- must return plant nutrients to the soil;

Culturally acceptable
- must be aesthetically inoffensive and consistent with cultural and social values;

Reliable
- must be easy to construct and robust enough to be easily maintained in a local context;

Convenient
- must meet the needs of all household members considering gender, age and social status;

Affordable
- must be accessible to all households in the community.

As the above aspects are fully consistent with UNDP policies and strategies, UNDP has embarked on a project to support further development and dissemination of ecological sanitation with initial funds from SIDA.