Ecological sanitation: Difference between revisions

Ecological sanitation, or EcoSan, is the term used in WASH circles to describe sanitation systems which are dispersed (rather than being based on sewers and large municipal wastewater treatment works ) and which aim to encourage people to view their own waste as a potential resource rather than as a problem.^[1] This has wide applicability in countries that have complex sewerage systems as the 'flush and forget' mentality is found almost everywhere.

Ecosan and composting toilets are terms that are often used interchangably and can be poorly defined. It is probably best to consider composting toilets as part of Ecological Sanitation, which can and should contain a range of other processes.

Concept: that sanitation problems could be solved more sustainably and efficiently if the resources contained in excreta and wastewater were recovered and used rather than discharged into the water bodies and the surrounding environment. The end-of-pipe sanitary systems that are used today are based on the modern misconception that human excreta are simply wastes with no useful purpose and must be disposed of.^[2]

Resources

The resources in wastewater are:

• Nutrients, which can be used for agriculture.

Energy is another resource which may be obtained which can be accessed through biogas or other techniques - see Energy from wastewater. This is often not a focus of EcoSan

Features

The UNDP lists the principles of ecological sanitation as follows:

• 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.

In practice

In practice, Ecosan is used to describe devolved sanitation systems whereby users are expected to manage their own systems and (usually) deal with their own sludge. People often mean different things, but usually it involves a Composting toilet, which might be a Single pit latrine, a Single Ventilated Improved Pit latrine or a Double Ventilated Improved Pit latrine whereby users have added ash, sawdust or other material in an effort to encourage breakdown and the destruction of pathogens. Material is usually stored for an extended period of time, sometimes is subject to secondary treatment (such as co-composting) and spread to agriculture.

Urine Diversion Dry Toilets are often considered to be a useful concept in ecosan as the urine has a relatively low risk of pathogen infection, and so can be kept clean and used directly in agricultural production.

This concept might be contrasted with Open defecation where untreated excrement is left on the soil surface as a waste and health hazard and even large pit latrines where sludge is left in a large tank over a period of time and is liable to drain into groundwater and affect the quality of drinking water.

References

Ecological Sanitation Handbook 2004, Stockholm Environment Institute Template:Reflist

See also

• Practical Action brief about reuse of feces and urine from ecosan
• Composting toilets