Ecosan at school
We think ecological sanitation offers a solution for many schools in developing countries. Schools in developing countries often have scarce water, money and food resources. Ecological systems require a minimum of water. Ecological sanitation saves at least 20/40 % of its domestic water consumption. Adding water saving devices or recycling grey water makes it even possible to save more water. After filtration, grey water can be used for irrigation, groundwater recharge or even for production of portable water.
Regarding scarce food resources ecological sanitation enables of 80-90% of the nitrogen, phosphorus and potassium in excreta and waste water to be recycled for agriculture use. This provides inexpensive local fertilizers who can be used for trees, crops and plants in school gardens.
Ecological sanitation is also a good sanitation option to save money of schools and communities. Ecological sanitation can locally be managed with low construction costs. Moreover, it creates local business opportunities for construction, operation and maintenance of sanitary facilities. They can help long-term poverty alleviation through enhanced food production and local business opportunities by sale of fertilizer products.
But, most importantly, ecological sanitation offers a safe sanitation option for our children. An essential step in the process of ecological sanitation is the containment of pathogens in the faeces that can cause diseases. Without containment and sanitisation, a vicious circle develops where the pathogen excreta is released back to the environment, re-infect people through consumption of contaminated water or food, and are then excreted again only to begin the cycle over.
Ecological sanitation provides two possible processes to render human excreta innocuous: dehydration and/or decomposition. In both processes urine and faeces are managed separately. Because faeces are stored in a dry place, bad smell is taken away. Therefore no flies are attracted to the excreta and pathogens are eliminated. It depends on the climate (wet or dry) which process will be dominant. With dehydration the deposited faecal matter may be dried by the addition of lime, ash, or earth. The contents are simply isolated from human contact for a specified period of time to reduce the presence of pathogens. Decomposition is a biological process carried out by bacteria, worms and other micro-organisms. These micro organisms break down the organic substances producing compost. These processes will be optimal when the place to store faeces is warm enough. Because the faeces are properly sanitized they are incapable of spreading disease and can be safely recycled.
School sanitation involves many children. Children have higher risks of illnesses than adults do. It is therefore even more important to be very careful when recycling human waste. Since faeces contain less nutrients and many pathogens and the value for soil is low we do not recommend to use faeces as fertilizer. When the excreta is dry or composted they can simply be buried. Urine on the other hand contains almost no pathogens and a lot of nutrients. It is safe and profitable to use as fertilizer for the school garden or other agricultural purposes when the instructions are followed properly.
