Article Courtesy: The Morung Express
Author: S Vishwanath
The technology choice that China made for sanitation and wastewater management has led to not only blistering economic growth but also rapid urbanisation as it helped Beijing reduce GDP loss that poor sanitation brings
The four storied apartments in Dongsheng District of Erdos Municipality in Inner Mongolia, China look like any apartment, all 825 of them. They look the same that is until you use the toilet. Detailed instructions nailed to the door tell you how to use them. The urine diverting toilets flush with sawdust instead of water. Urine is collected in tanks tucked away in the basement of the building and used as a fertiliser in a surrounding agricultural field. The solids are composted and reused also as fertiliser. Grey-water coming from the washing machine and bath is treated at a small treatment plant in the development and reused for landscape use. The people who bought the flats did so knowing fully well the systems of sanitation in place and paid the same market rates as the flats which had conventional sanitation systems. This is China’s brave new world of waste and wastewater management.
China, and rural China in particular, has been well-known for centuries for reusing human waste as a fertiliser. Legendary tales are told of farmers competing with each other in inviting passers-by to use toilets in their fields so that they could access the fertiliser. There was never any waste only a resource according to the Chinese farmers. This was, however, a small part of the story.
Rural sanitation has been a problem for long. In 1996, only about 20 per cent of households had access to sanitation. The prevalence of open defecation, the use of the traditional pit latrines and in general bad sanitation practices, including the application of untreated human waste for agriculture, had led to the high prevalence of intestinal diseases such as worms in the rural population. A focussed attention first on rural drinking water supply improvement then followed by sanitation access improvement has resulted in about 50 per cent of the populace having access to safe sanitation by 2003. The technology choice made for sanitation was also interesting. These included five major types of sanitation systems — the triple compartment septic tank type, the double barrel urn type, the methane generation digester type, the eco-san separate urine faeces collector type and finally the conventional sewer type.
While the first and the last are designed exclusively for isolating and treating sewage to safe standards only, the remaining three systems are designed not only for safe treatment but for reuse of nutrients as well as for generation of energy in the case of the methane digester type.
Take the case of the urine diverting dry toilets. The UDDT’S have a pan designed that collects urine and faeces separately. In the case of washers the wash water is also collected separately. The first experiment in Guangxi Province started with the construction of 70 toilets in Dalu village in 1997. This was followed by the construction of 10,000 UDDT’s in 1998 and then scaled up to the construction of 6,85,000 toilets in 2003. The construction of the UDDT’s has thus been mainstreamed as one of the sanitation alternative while providing the nutrients that farmers need for their fields in a safe and hygienic manner.
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