One man, one organisation, one town in Tamil Nadu has adapted and proven a non-polluting toilet design. In fact, it enriches the land and increases crop productivity
Sopan Joshi | October 22, 2014
In times when it is fashionable in the development sector to say “I am a shit man”, Marachi Subburaman cuts a strikingly underwhelming figure. He certainly does not look like the kind of man who has helped build more than 20,000 toilets in Tamil Nadu’s Tiruchirapalli district (Trichy for short) – and helped established a toilet design that is nothing short of the ideal, especially for rural India.
At the age of 26, Subburaman started working for an organisation in Andhra Pradesh that helped poor people build low-cost houses. That was 1976. He used to go from village to village, dealing with several types of building material. His road-to-Damascus moment came in his first year. At a village he was visiting, he wanted to relieve himself in the morning. He was taken to the village tank, by which the villagers relieved themselves. His enquiries revealed the village had only one tank; the water Subburaman had drunk the previous evening after alighting from the bus had come from the same tank.
“I was horrified,” says Subburaman, now 65. He walked away, squatted behind a bush, came back to his shed, dug a pit in the ground, bought a toilet pan for '25 from a nearby town, and installed it above the pit – all before the next dawn. The following day, he relieved himself in the privacy of his makeshift toilet, in the added relief of not defecating into the water source. That improvised toilet is still standing in that village, he says.
In 1986, Subburaman formed an organisation called SCOPE in Trichy to work on creating avenues for women’s groups to improve their incomes. While the income increased due to several productive occupations like making soaps and candles and weaving mats, better income did not bring a better life. A major reason was medical expenditure on treating infectious diseases, many of which were rife because drinking water was contaminated with faeces.
SCOPE took up several projects to build toilets, along with its other efforts. When the central rural sanitation programme (CRSP, launched in 1986 to provide grants to construct toilets in villages) reached Trichy, Subburaman persuaded the district authorities to invest all the funds in one village. The idea was to make sanitation work in an entire village. Thus, Devapuram in Trichy became a model village for sanitation in 1990, drawing the attention of the state and central governments.
In 1997, when the central government was reviewing CRSP, SCOPE was invited to the committee that formulated the total sanitation campaign (TSC, launched in 1999, later renamed the Nirmal Bharat Abhiyan). Under this, the organisation prepared a block called Musiri for intensive toilet construction. Both the Musiri town panchayat and SCOPE were among the initial winners of the Nirmal Gram Puraskar.
Necessity, the mother of invention
One part of Musiri, though, has an irrigation canal from the river Cauvery running through it. Percolation from the canal had raised the water table of the area. In this area, it was impossible to make and use toilet pits; the excreta floated up due to the high groundwater level, especially six months after the rainy season. This is when a UN official told Subburaman about the invention of Paul Calvert.
A British marine engineer, Calvert worked each winter along the coast of Thiruvananthapuram in a fishing village. There, despite most houses having latrines, open defecation was widespread; Calvert often ran into faeces on the coast. Reason: the high water table in the area made toilet pits difficult to construct, and even more difficult to use, as the waste floated up. Calvert was familiar with the concept of ecological sanitation (or EcoSan), created by Swedish urban planner Uno Winblad (see box: What is EcoSan?).
Based on Winblad’s work, Calvert had designed a toilet with separate receptacles for urine and faeces. In this, faeces were contained inside a chamber, where it could dry up and get disinfected slowly, without posing any danger to public health or fouling the sight and smell of the beach. Each toilet had two separate pans, with two different chambers underneath. When one filled up, it was sealed and the other one was opened.
After faeces had decomposed thoroughly in the sealed chamber, the excreta turned into good fertiliser for crops. Urine, almost entirely free of germs, was diverted to a vessel from where it was applied to plants after being diluted with water; urine is a rich source of urea and phosphate for plants. This design required people to move forward after defecating to clean themselves with water that went out separately. All effort was focused on keeping faeces dry, hence in an ideal state for safe decomposition.
Calvert’s toilet design made sanitation available in the village with high water table. Subburaman was immediately drawn to Calvert’s story. Along with some state government officials and friends in NGOs, he invited Calvert to Tamil Nadu. They soon adopted his design to Musiri’s requirements. Subburaman played around with the design and created a pan that was even cheaper and simpler to use.
Such ‘urine-diverting dry toilets’ (UDDT) are easy to use in countries where people are used to cleaning themselves with toilet paper after defecating. Paper is dry, and decomposes well with the faeces. But in a country like India, where people are used to washing themselves after defecation, this is a serious problem. Water from washing can make a puddle in the faeces chamber. Here, Subburaman tried out his ideas.
Instead of two parallel pans, he designed one pan with one hole at each end for feaces, with two separate chambers underneath. In between was the hole to urinate into, which remained common regardless of which side of the pan was in use and which was sealed off to allow the faeces to decompose. In this pan, the user has to move back after defecating to cleanse himself or herself. The urine, faeces and cleansing water go into separate holes. The separation is the key: it allows each to be dealt with at little to no cost.
An ideal treatment system
There are several reasons UDDT design is so good. One, it contains the millions of pathogens found in faeces – one gramme of faeces can contain up to 10 million viruses, one million bacteria, over 1,000 parasitic cysts, and over a 100 eggs of worms – and prevents them from escaping and infecting other people. When the faeces dry out and remain isolated in a chamber over weeks and months, they decompose and break down into harmless soil nutrients – what they indeed were before humans ate the food: nutrients from the soil prepared into food. This means valuable soil nutrients take out in the form of crops are returned to the soil. Scientists call this closing the loop on nutrients.
Estimates by soil scientists show about 10 million tonnes of soil nutrients are washed away to sea in India each year due to the sewage system. (Just to get an idea of the value of soil nutrients, remember that the government’s annual bill for fertiliser subsidy is more than '65,000 crore.) While faeces are rich in carbon content, urine is rich in nitrogen and phosphate. If these can be returned to the soil without posing any threat of infections, it is the ideal. Because it mimics the way nutrients are recycled in nature. It is ideal for soil conservation.
Two, ecosan toilets save water and electricity, the two biggest expenses in water-borne sewerage. UDDTs eliminate the need for sewage treatment plants, elaborate network of sewers to transport the sewage, the installation of large mechanical pumps run by electricity to pump the sewage through the sewers, and the expenses on maintenance and operations of such systems. This is where all Indian cities fail: Delhi, for example, has about 22 percent of India’s total sewage treatment capacity. Yet more than 35 sewage treatment plants cannot clean the city’s sewage. This results in the gross pollution of the Yamuna, which has nothing but untreated sewage flowing in it in Delhi; the city withdraws all the river water upstream to provide to bathrooms and kitchens, which turn it into sewage and return it to the river.
Three, ecosan can provide sanitation in extreme areas. In fact, this method got a big boost in the efforts to rehabilitate coastal areas destroyed by the December 24, 2004 tsunami that came across the Indian Ocean. It left several coastal areas with very high water tables. Which made both pit latrines and sewer systems difficult to build and maintain. Ecosan toilets could contain excreta (and the infections it can unleash) even in water-logged areas. Some social groups have made ecosan toilets work in flood-prone areas of northern Bihar.
Ecosan can work in desert areas, where water scarcity necessitates frugal use of water. In rocky areas where it is not possible to dig for pits and sewers, this design is ideal. It is also preferable in areas prone to earthquakes, as there is no danger of sewage leaking through cracked sewer lines or pits. One critical advantage of UDDTs lies in maintaining groundwater quality. Soak pits or leach pits, used widely in India, lead to leaching of excreta into aquifers. Tests conducted in several Indian cities have shown evidence of nitrate contamination in groundwater, which clearly points to untreated sewage.
Most Indian cities have an incomplete network of sewers. Hyderabad and Bangalore, for example, have less than half the households connected to the sewerage. The remaining households let their sewage into pits, where the excreta does not decompose quickly (as it would in, say, a UDDT’s decomposition chamber).
Densely populated areas?
In the 1990s, Musiri had a public toilet that was the definition of a cesspit. It stank, sewage oozed into the irrigation canal, creating a stink and an eyesore. SCOPE and the Musiri town panchayat decided to convert this into an ecosan public toilet. Initially, to encourage people to use this toilet, they were paid Re 1 to use it. In the face of the pay-per-use system that is gaining currency due to the work of Sulabh International, here was a toilet that benefitted its users.
Since then, the earn-per-use scheme has been rolled back. If you go to Musiri, panchayat leaders proudly take visitors to see their urine-diverting dry public toilet, and pose in its premises as if it were a shrine. In fact, given the centre-stage cleanliness is now acquiring in the public discourse, it is no exaggeration to call Musiri’s public toilet the Taj Mahal of sanitation. There are seven toilets for men and seven for women. Each has two pits under it, which are opened and sealed in rotation. The urine goes through a charcoal filter and is collected. From here, it is taken in vessels to an experimental farm, where the benefits of nutrients to agriculture have been studied and documented. Trichy’s national research centre for banana has published the results of their studies.
An additional profit of '45,000 was obtained from each hectare of banana cropland which had received urine from Musiri’s public toilet. Of this, '36,000 was due to increase in productivity and '9,000 was due to savings on artificial fertilisers. This gives an indication of the kind of prospective profits urinated into the sewers of India each day.
A realistic estimate of this potential came from a remarkable collaboration in Bangalore. Arghyam, a non-profit that works on water and sanitation, collaborated with the state agriculture university to harvest urine from a school urinal, and apply it to experimental farms. The results are surprisingly elating.
Each year, almost eight million tonnes of nitrogen, phosphorus and potassium can be obtained from urine of India’s total population. In trials on maize, the produce from land fertilised with urine was significantly higher than from land that had artificial fertiliser applied to it. Not to mention the savings of '2,000 per hectare. Urine-treated banana plants produced fruits bigger than average size – the bunches were bigger, too, as compared to plants not treated with urine. Tomato, capsicum and musk melon showed similar results.
Musiri has become the inspiration for several ecosan efforts across the country. Subburaman spends a lot of time on the road, lecturing and advising people who have an interest in the EcoSan story. With an eye trained while building low-cost houses, it takes him a moment in a moving car to spot a badly designed toilet gas vent. Likewise, he can instantly tell a good location for building a toilet – and he is always quick to point out a toilet pit built near a water source or a tube-well or a hand-pump.
He can list why engineers struggle with toilet design: because toilet design is not covered in civil engineering courses. He has about 25 designs for UDDTs, depending on the requirements. Subburaman is not a pushy man. He offers options for toilet design to people.
Typically, he says, people who opt for an ecosan toilet do not have the option of water-borne sewerage. It remains a solution for difficult locations only.
For people used to defecating in the open, a UDDT is a highly suitable toilet design – they are used to moving after defecation to wash themselves. But people used to a flush toilet find it inconvenient. For a country looking around desperately for sanitation solutions, it is a great idea that can be adapted to several situations.
To see how, one is advised a visit to Subburaman’s new, multi-storeyed house in Trichy. His family members do not want UDDTs, so they have standard toilets connected to the sewer. Next to his second floor bedroom is Subburaman’s bathroom. It has two commodes. One is a UDDT and the other connected to the sewer. He uses the dry toilet. But he is not the kind of man who will impose his ideas on others. He merely offers and invites.
EcoSan: how it began
Architect and town planner Uno Winblad was born in Sweden in 1932. His specialisation, however, was in tropical architecture. In 1970, he got an assignment to draw a plan for urban settlements in Ethiopia. Winblad had realised that the modern, European idea of the city had some serious defects, which made it unsuitable to regions with different physical conditions and limited water resources. Like Ethiopia.
In particular, he began to question the logic of sewerage, a highly water-intensive way to manage excreta, and pit toilets, a cheaper version of water-borne sanitation that can contaminate groundwater. In 1978, he wrote a book called ‘Sanitation Without Water’. From here onwards, toilet designs became Winblad’s preoccupation.
He revised his book under the title ‘Ecological Sanitation’, and since then, it has become something of a bible for those looking for sustainable ways of sanitation. It is a bestseller now available for free download, and has been translated in several languages. For Winblad, EcoSan saves on only water; it is an ideal way to conserve soil nutrients. Besides, it is cheap.
“Conventional waterborne sewage systems have proven to be inappropriate to solve sanitation needs in developing countries,” he writes in his path-breaking book. “The systems are too costly to be provided to all, and only wealthier upper and middle class areas are normally provided with those services. Approximately 90% of the sewage in cities in developing countries is today discharged untreated, polluting rivers, lakes and coastal areas.”
Winblad’s work made Sweden a hub of EcoSan. Even today, the greatest support for the idea and its attendant technologies comes from the Swedish Environment Institute.
This story appeared in the October 16-31, 2014 print issue
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