What is ecosan (ecological sanitation)

Ecological Sanitation for Eco-system-based Societies

Ecological Sanitation (ecosan) is an approach that offers many advantages over and above sanitation provision, an otherwise much neglected issue. Ecological sanitation is aimed at closing the nutrient and water cycles. Ecosan prescribes that human excreta along with household organics are sanitised and the resulting plant nutrients are reused in agricultural production in the proximity of human settlements. Water from the households’ showers/baths and kitchen, i.e. greywater, undergoes treatment and can subsequently safely be re-cycled. Ecosan proposes sanitation that limits the use of water as a means of disposal. This is a particular advantage since water shortage affects more than 80 countries and 40% of humanity. In contrast, water-based sanitation discharges of untreated sewage into rivers and other bodies of water represent a severe problem around the world with 90% of towns and cities in developing countries lacking sewage treatment. In 2001 only 80 out of 550 large European Union cities had advanced/tertiary treatment. Another acute problem is contaminated sludge from conventional treatment facilities making it impossible to reuse.

Focus on Closing the Loop on Sanitation

Ecological sanitation includes source-separation of human excreta into urine and faeces fractions, recovering the nutrients for reuse in local cultivation. Human urine contains about 75% of the nutrients excreted by the body and represents about 80% of the total excreta volume. Sanitized faecal matter, composted with household organics, is an excellent soil conditioner. Using these approaches, ecosan enables environment-friendly recovery in contrast to many conventional waste-based sanitation systems that mix human excreta with storm water runoff and industrial effluents creating a mega-sized water treatment problem, which is difficult for most cities around the world to cope with. Most of the world’s sewage treatment plants produce effluents containing human pathogens, nutrients and toxic compounds. Pit latrines, septic tanks and cess pits often contaminate the ground water, the largest source of freshwater on the planet. Ecological sanitation represents a new approach to sanitation, whereby human excreta is recovered to soil systems and kept away from surface and ground water systems.