Ecological Sanitation (ECOSAN) is an environment friendly sustainable sanitation system which regards human waste as resource for agricultural purposes and food security. In contrast to the common practice of linear waste management which views waste or excreta as something that needs to be disposed, ECOSAN seeks to close the loop of nutrients cycle, conserve water and our surrounding environment. The basic principle of ECOSAN is to close the loop between sanitation and agriculture without compromising health and is based on the following three fundamental principles:
- Preventing pollution rather than attempting to control it after we pollute
- Sanitizing the urine and faeces
- Using the safe products for agricultural purposes
The goal of closing the nutrient and water cycles is need to be fulfilled on a large scale to render current sanitation practices an eco-friendly one. However, it is generally agreed that it is wise to reuse nutrients and save resources. The ECOSAN toilet technology fulfils this aim and provides effective alternative solutions, with or without water, because this technology can be viewed as a three step process dealing with human excreta i.e. containment, sanitization (treatment) and recycling.
Basic principles of ECOSAN Latrine:
- Offers a safe sanitation solution that prevents disease and promotes health by successfully and hygienically removing pathogen-rich excreta from the immediate environment.
- Environmentally sound as it doesn’t contaminate groundwater or save scarce water resources.
- Recovers and recycles the nutrients from the excreta and thus creates a valuable resource to reduce the need for artificial fertilizers in agriculture from what is usually regarded as a waste product.
Every day each person of India’s 1.02-billion populations (2001 Census) produces 1-1.3 litres of urine and 250-400 grams of faeces which are flushed with grey water to become town sewage get deposited in pits of on-site sanitary latrines or are simply delivered in the open – in fields in rural areas and urban open spaces.
The “flushing system” commonly used in urban areas is considered highly sanitized but only if city sewage is fully treated. Studies indicate that in India less than 10 percent of sewage is treated and rendered harmless before it is discharged into water bodies and rivers. Every day millions of litres of fresh water goes down the drain with flushing of toilets. In small towns septic tanks, cesspools and open drains carry sewage in the absence of a planned sewer system. They often have leakages and poor and faulty constructions that lead to polluting of water pipes.
An effective response to this public health threat lies in an alternative system of on-site disposal and treatment of sewage termed “ecological sanitation.” Ecological sanitation is based on three fundamental principles: (a) Prevent pollution rather than pollute and then undertake costly and energy-intensive treatment. (b) Sanitize urine and faeces for recycling as useful natural resource and (c) Utilize the products (rendered safe) for agriculture or horticulture.
In India, ecological sanitation is practiced in different forms in various parts of the country like Leh-Ladakh and Lahaul Spiti in Himachal Pradesh and more recently in Tamil Nadu. In the 1990s, practitioners and innovators in the field of sanitation, primarily NGOs, while searching for low-cost solutions for difficult hydro-geological conditions began experimenting with alternate designs and systems including ecological sanitation in both rural and urban areas.
The design of the eco-toilet is based on the following principles:
- There is no pit in the ground; instead there are two chambers above the ground. This ensures there is no pollution of ground water.
- Separation of the solid waste (faeces) and the liquid waste (urine+wash water). The separation is essential as faeces kept separate from liquid waste desiccate and disintegrate faster and occupy less space. Separation also prevents bad odour which results from mixing of urine and faeces.
- The user of the toilet will defecate in the defecation hole and the urine is drained separately. Then the user has to move a foot backwards or sideways to wash in a separate washing trough.
- The liquid waste (urine+wash water) is drained through a mud pot into the earth adjoining the toilet about one foot below surface. This earth is below a small square plot which is used for horticulture or growing sturdy flowering plants. The waste is good for plant growth as nitrogen from urine feeds the plants directly and the pathogens in the wash water remain under the ground and become inactive in a few days.
- The second chamber is used only after the first is full.
- The full first chamber is to be opened through a lateral/back opening (closed by a single slab) only after one year has elapsed.
- The products of the first chamber – which become free of pathogens like bacteria, viruses and protozoal cysts after a year – is black humus with a pleasant odour. It is good manure, rich in nitrogen, phosphorus, and potassium, the three elements required in greatest quantities by plants, and an excellent conditioner that restores health and productivity of the soil.
- The users of the toilet have to understand the primary principle on which eco-friendly compost toilets are based. A family, once convinced of the usefulness of the system, and the gains in terms of water use and quality manure, is willing to contribute or spend money on constructing such a toilet.