Evidently, sanitation needs to be strongly infused with an approach which not only safeguards hygiene by preventing pollution of water resources but also re­enforces the sustainable use of water.

‘Water and sanitation’ is recognized worldwide as one of the most critical areas of development planning and implementation. Yet, clearly, different levels of coverage have been achieved when the two areas are separately looked at. In the six decades since Independence, India has witnessed phenomenal development in supply of drinking water - around 86%. However, this achievement has been at the cost of groundwater depletion, water logging and increasing salinity levels affecting large areas of the country. On the other hand, coverage of improved sanitation has been around 33% and only 15% of the rural population has access to a ‘functional’ toilet.

Conventional ‘end-of-pipe’ sanitation systems based on water-borne sewerage systems and centralized treatment facilities are unsustainable. Apart from being capital intensive, they are prone to breakdowns on account of inadequate maintenance or unavailability of water. Typical alternatives include the septic tank or a pit latrine (singe or double pit pour flush types). Both are water-intensive, needing 10- 121itres of water per usage. These systems tend to pollute the groundwater - often rendering wells unusable - where issues like proximity of water sources to toilets, sub­surface strata and high groundwater level are overlooked while meeting the sanitation targets. Moreover, majority of masons are ignorant about scientific construction methods of septic tanks and the environment friendly treatment of sludge is virtually non-existent. All these problems are far more acute in the developing regions of the world where polluted water related deaths still take a heavy toll.

In 2000, the Bellagio Principles formed the basis for a new paradigm and approach in environmental sanitation. Ecological Sanitation, or Ecosan as it is commonly referred to, calls for environmental security at the household level, stakeholder participation and integrated water resources management. The new approach recognizes human excreta and water from households not as a waste but as a reusable resource. The core principle, as opposed to the process that is used in practice, is to close material flow cycles instead of a linear flow of nutrients from agriculture, via humans to recipient water bodies. Ideally, Ecosan systems enable an almost complete recovery of all nutrients in human excrement and their re-use in agriculture. They restore a natural balance between the quantity of nutrients excreted by a person in one year and that required to produce food - 7.5 kg nitrate, phosphorous and potassium to produce 250 kg of grain.

Diverse technologies can be used in Ecosan systems, from quite simple low­tech to sophisticated high-tech solutions. These structures currently range from compost toilets or urine-diverting dry toilets to water-saving vacuum sewage systems, possibly with separate collection and subsequent treatment of urine, faeces and grey water through to membrane technology for material separation and decontamination. The treatment solutions include prolonged storage, vermi-composting, sludge de­hydration and constructed wetlands! ponds for grey water. Modular design of Ecosan systems allows optimal adaptation to the local social, economic, ecological and climate conditions.

The dry toilet is the most viable aspect of Ecosan in India. Typically, Ecosan toilet is a twin chamber toilet, one of which is used for defecation till it fills up, while the other one is kept sealed. Faeces, urine and wash water are collected separately by designing the toilet accordingly. Human waste gets com posted in about 8 months when it is free from any disease-causing pathogens or bacteria. The wash water and urine, after dilution, can be used for watering plants near the toilet. Proper design and use of Ecosan toilets can bring down water requirements to a litre per day for a family. They can be constructed almost anywhere.

The success of Ecosan has been demonstrated at both the institutional level and household level in India. German Technical Cooperation (GTZ ) has been instrumental in creating the first demonstration of Ecosan toilets in India and in developing a network of resource organizations for Ecosan design, implementation and training. Paul Calvert of Eco-solutions has developed urine diverting dry compost toilets with evaporative plant beds in Kerala. Society for Community Organization and People’s Education (SCOPE) constructed 250 Ecosan toilets, at a cost of Rs. 6500 per toilet, in the coastal areas of tsunami-hit Nagapattinam district. UNICEF has appointed SCOPE as technical consultant for Ecosan concept of dissemination and training of masons.

A number of different stakeholders may be involved in Ecosan projects. NGOs can be instrumental in information and awareness raising, training communities in use of eco-sanitation systems and linking them to financial institutions, municipalities, producers of Ecosan equipment, etc.. Re-use of recyclates (organic material and nutrients) is an integral part of the Ecosan approach and may need the involvement of external agencies for collection, transport, treatment and packaging. Large-scale application of Ecosan sanitation systems may necessitate the involvement of financial institutions, such as local or international banks or donor agencies. Local government institutions could establish a framework to integrate Ecosan services into local or regional sanitation programmes.