Ecological Sanitation

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Ecological sanitation is based on the 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 being used today treat human excreta as wastes to be disposed of as no useful purpose can be served with them.

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Why should I be aware of this?

Ecological sanitation is a new paradigm in sanitation that recognizes human excreta and water from households not as waste but as resources that can be recovered, treated where necessary and safely used again.

With ecological sanitation system nutrients in household wastewater can be fully recovered and reused in agriculture. This not only helps preserve soil fertility but safeguards long-term food security, while bringing down the consumption and pollution of water resources to the minimum.

Ecological sanitation and environment

Because of inadequate treatment processes, sewerage systems can cause environmental pollution. Most of the sewerage systems in developing countries do not treat waste prior to discharge. This not only causes environmental pollution but also increases health risks to communities living near receiving water bodies. Ecological sanitation provides on-site treatment and the by-product is most often re-used locally, eliminating large scale pollution.

On-site facilities can also cause environmental pollution, initially as a result of seepage into groundwater. This problem is mitigated in ecological sanitation as this system contains excreta in sealed vaults or stores them at only a shallow depth.

All about ecological sanitation

Ecological sanitation technologies go beyond taking care of environmental sanitation and include wastewater treatment and disposal, vector control and other disease-prevention activities. Ecological sanitation is structured on recycling principles. It means keeping the eco-cycle in the sanitation process closed. It is also a low-energy approach that uses natural processes.

A more holistic approach towards ecologically and economically sound sanitation is offered by the concepts referred to as "ecological sanitation". The key objective of this approach is not to promote a certain technology, but rather a new philosophy of dealing with what has been regarded as waste in the past. The systems of this approach are based on the implementation of a material-flow-oriented recycling process as a holistic alternative to conventional solutions.

Ideally, ecological sanitation systems enable the complete recovery of all nutrients from faeces, urine and greywater to the benefit of agriculture, and the minimisation of water pollution, while at the same time ensuring that water is used economically and is reused to the greatest possible extent, particularly for irrigation purposes.

Drawbacks of conventional systems

Conventional forms of centralised sanitation are coming under increasing criticism. Especially because of the enormous investment involved, the huge operating and maintenance costs, high water consumption and other drawbacks, they are not suitable as a blanket solution for developing countries, particularly in arid zones.

Even conventional individual disposal systems, such as latrines and cesspits, make poor alternatives - especially in view of increasing population densities and the substantial groundwater pollution they can cause. Moreover, all conventional types of wastewater and sewage disposal systems usually deprive agriculture, and consequently food production, of the valuable nutrients contained in human excrement.

Ecological sanitation types

There are two types of ecological sanitation toilets:

  • Dehydrating, and
  • Composting

There are two further distinctions:

  • Urine diversion (those that separate urine from faeces to achieve a variety of benefits), and
  • Systems which mix both urine and faeces.

There are two types of treatments: primary and secondary. Primary treatment occurs on-site through such processes as increasing pH level or reducing the moisture content. During the secondary treatment the waste is transported to an alternative location (off-site) for further treatment such as composting or incineration.

Many household facilities perform secondary treatment by leaving the waste in storage and not adding further faeces i.e. an alternating pit system. If human waste is collected and mixed together to be used on a large scale further secondary treatment should take place to ensure it is pathogen free.

Unlearn

The main risks associated with ecological sanitation result from either mismanagement of the facilities or poor construction of facilities. Mismanagement takes place when enough storage time is not allowed or water is not allowed into a dehydrating system. As a result the pathogen content of the waste is not reduced to safe levels, and this becomes risky for:

  • those responsible for emptying the facilities;
  • workers who spread the excreta across the land;
  • farm workers who plant crops or walk on land to which by-product is applied; and
  • consumers of crops that do not require cooking which have been fertilised with the excreta.

But the biggest threat to the success of ecological sanitation is the unwillingness on the part of householders to handle human waste.

Eco Sanitation Organisations

  • Agricultural University of Norway
  • UNDP
  • Sida (Sweden)
  • SARAR Transformacion SC (Latin America)
  • Espacio de Salud (Mexico)
  • GTZ (Germany)
  • Novaquatis EAWAG (Switzerland)
  • Water Page (Africa)
  • Aquamor (Zimbabwe)
  • Sanitation Connection
  • SUDEA (East Africa)
  • WSSCC
  • WSP World Bank
  • CITA (Mexico)
  • International Ecological Engineering Society
  • Ecological Engineering Group
  • EcoWaters (formerly Center for Ecological Pollution Prevention)
  • City Farmer
  • Mvula Trust (South Africa)
  • PHG Palestine Hydrology Group
  • Technical University Hamburg-Harburg
  • IWA Specialist Group on Sustainable Sanitation
  • WASTE
  • Eco-Solutions
  • The Hesperian Foundation
  • MAMA-86 Ukraine
  • Mvuramanzi Trust (Zimbabwe)
  • CREPA (West Africa)
  • Sustainable Sanitation and Water Renewal Systems (SSWARS), Uganda

References

  • Experiences of an ecological sanitation project in Malawi
  • Women, Wellbeing, Work, Waste and Sanitation action research successes in South Asia
  • Ecological Sanitation - A concept

See Also