News

doi:10.1038/nindia.2013.133 Published online 7 October 2013

India's quest for better toilets

K. S. Jayaraman

India's 4.5 billion rupees mission to Mars planned later this month (28 October, 2013) has been criticised by some as waste of money that could be better spent to solve more urgent problems on the ground. These critics have been partly silenced by the government's announcement of a $2 million (120 million rupees) project to develop the next generation toilet to treat human waste — a major health risk.

The project is the latest in India's quest for better toilets.

India is "drowning in its own excreta" with over 60 percent of its population — or 615 million Indians — still defecating in the open due to non-availability of toilets. Millions of tonnes of faecal sludge collected from pit latrines and septic tanks are discharged untreated into rivers, lakes and ponds. India needs "safe and affordable sanitation that effectively removes human waste from the environment while recovering components that can be recycled," says Krishnaswamy VijayRaghavan, secretary to India's Department of Biotechnology (DBT).

The programme jointly funded by DBT and the Bill & Melinda Gates Foundation (BMGF) seeks to achieve this goal. It was announced appropriately on the birthday of Mahatma Gandhi, father of the nation, who termed manual scavenging a national shame and called for its elimination.

DBT has invited designs from India's "best and brightest" scientists for a stand-alone, self-contained toilet that does not need electricity, gas or connection to a sewer. The technology should be suitable for use in different settings across India — from a single-family scale to a community. It should also be usable in train-cars to process human excreta on-board with no further transport of hazardous waste. The team that comes out with the best design will get a funding of $2 million to develop the prototype.

In 2008, an eco-friendly loo patented by Indian defense scientists used a consortium of anaerobic bacteria adopted to work at temperatures as low as five degrees Celsius, converting organic waste into methane and carbon dioxide. Though developed for treating human waste of soldiers stationed at glaciers and other low temperature areas, the technology has been used to develop bio-toilets for Indian Railways to ensure clean tracks. About 3,800 bio-toilets are already being used in trains and the Indian Railways intends to cover its entire fleet of passenger coaches by 2021-22.

More recently, the Indian Institute of Technology at Kanpur developed a "zero-discharge" toilet that separates 90 per cent of the liquid from the waste and reuses it for flushing. VijayRaghavan says through the new programme DBT hopes "to attract innovative new ideas as well as build on some great efforts that have already taken place."

Should a new toilet system emerge from this venture, there are already signs that it will get ample political support. Narendra Modi, the prime ministerial candidate of the opposition Bharatiya Janata Party has also announced that if his party wins the elections next year, "constructing toilets will take precedence over building temples."