Ecological Sanitation: A Concept
Practical Action
Ecosan is also growing to encompass both greywater (water used for washing clothes, cooking
etc.) and rainwater, in addition to solid waste (garbage collected in a household). This
technical brief will look simply at human waste, but references at the end of this brief provide
links to other publications.
Why Adopt an Ecological Sanitation Approach?
Sewerage systems have been developed in the many countries and could take on the form of
conventional, simplified or settled sewerage. The alternative to these systems are on-site
sanitation facilities. Supporters foresee that ecosan systems can reduce the environmental
pollution that other systems cause, in addition to recycling the valuable nutrients in the waste
and improving food security. The benefits of ecosan over the other types of system, alongside
some more general benefits are described below.
Sewerage Systems
Sewerage systems can cause environmental pollution as a result of inadequate treatment
processes. Approximately 90% of sewerage systems in developing countries do not treat waste
prior to discharge causing environmental pollution and increasing health risks to communities
living near receiving water bodies. Ecosan provides treatment on-site and the by-product is
most often re-used locally, eliminating large scale pollution.
Furthermore, sewerage systems require the use of large quantities of water to work effectively
and in many poor communities there is no reliable water supply. One estimate is that 20-40%
of water consumed in an average city goes towards flushing toilets. Ecosan systems only
require water where it is used for anal cleansing, therefore eliminating this burden on water
supplies.
On-Site Sanitation Systems
On-site facilities can also cause environmental pollution, initially as a result of seepage into
groundwater. Ecosan systems mitigates this risk as a result of containing excreta in sealed
vaults and/or storing them at only a shallow depth.
In urban areas the necessity to remove excreta from such installations can cause significant
risks to the local community and workers. Correctly operated ecosan systems can mitigate
these risks entirely by reducing pathogen content of faeces prior to removal. Further
advantages of ecosan over on-site systems are that they generally smell less (attracting fewer
flies), and in areas with hard ground or a high water table pit latrine construction can be
problematic, ecosan overcomes this with options that do not require ground excavation.
Further Benefits
Ecosan systems have not always been driven by a need to recycle nutrients, water scarcity,
high water tables, rocky ground and a need to minimise pollution are alternative reasons for
adoption (Esrey and Andersson, 2001). Urban dweller’s lack of land may mean they have no
use for compost, in this case the material could be bagged and sold to generate further
income (ibid), although this can be a problematic task to carry out if not done collectively.
The use of ecosan has the potential to provide communities with food security for many years
to come, as the compost not only provides nutrients, but also conditions the soil to which it is
added.
In many areas subsistence farmers find it increasingly difficult to meet the costs of fertilisers,
ecosan provides them with a cheap alternative to supplement their needs. Ecosan can also
generate income through construction, operation and maintenance of facilities, providing bulk
treatment in urban areas and re-sale of by-products.
As a result of being a low odour technology, ecosan also enables facilities to be constructed
both inside and outside the home. Facilities constructed indoors can provide a safe and
private environment for both women and children.
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