Clean Tech

Chugging on towards change

Mamuni Das | Updated on January 20, 2018 Published on June 07, 2016

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While bio-toilets in Indian trains are on track, the challenges are many, writes Mamuni Das

A colony of bio-digesting bacteria, which feasts on human faecal matter — converting it to water, carbon dioxide and small volumes of hydrogen and methane gas — was found fit to fix a big challenge for Indian Railways. The task at hand: ensure no human waste is evacuated on to the 110,000 km of rail tracks from some 12,000 trains that carry over 20 million people every day.

Originally, the bio-digesting technology was developed by Defence Research and Development Establishment (DRDE), Gwalior; a unit of Defence Research and Development Organisation, for use at the Siachen glacier. It’s also used in islands like Lakshadweep and Male, where the water table is high. Except these were stationary toilets.

For the Railways, the target to install 160,000 such toilets for all the trains has been advanced by two years to October 2, 2019 from 2021.

“We are the only country globally that has taken a task (Railways) of such size and scale. We have installed 35,000 toilets (four for each coach) in trains and have a budgeted target to install 30,000 toilets this year, which we will try to exceed,” Hemant Kumar, Member-Mechanical, Railway Board, told  BusinessLine. At 30,000 a year, another four years will be required to cross the deadline.

The challenges

Over the last few years the Railways has had to modify the bio-toilet solution multiple times to suit its requirements and make passengers aware about the use of these toilets. For instance, toilet tanks — which are fitted in the space between coaches and tracks — had to be built from sturdy material. “Initially fibre glass was used, but it could crack and leak when stones from ballast hit them. Then, stainless steel tanks were used as they are non-corrosive,” shared Kumar.

Another challenge has been to deal passenger behaviour of throwing non-biodegradable materials such as plastic bottles and napkins which choked the toilets.

Indian passengers are used to disposing pretty much everything through the toilets that open on to the tracks, and for the passenger, toilet interface does not change even if a tank with excreta digesting bacteria is fitted underneath.

The earlier avatar of the bio-toilet did not have valves, and non-biodegradable material could easily go in resulting in the choking of toilets. “The design was modified to add a valve that opened and discharged non-biodegradable matter to the tracks, allowing only the faecal matter to go into the tanks. Then, it was found that the water discharge was clear of several germs, but had E. Coli traces. So it is now chlorinated to ensure that the discharged water meets the requisite norms. We test the discharged water regularly,” he explained.

One of the other problems is that of controlling the toilet’s weight.

“Each toilet weighs about 150-200 kg, adding up to 500 kg while in use. So, an additional weight of up to 2 tonnes has to be taken by each coach. The toilet retro-fitment also requires changing the springs in some coaches,” said Kumar.

And while these are anaerobic bacteria — meaning they can survive without aeration — they do need food to survive. The bacteria colony dies if it does not get feedstock. Hence, if trains are not used for two months, it would require refilling of the tanks. “They digest the faecal matter slowly if the waste is too diluted. After all, the toilets have to be self-sustaining.”

Evolving technology

No wonder even now a joint working group of officials from DRDE, officials from production units such as the Rail Coach Factory, Integral Coach Factory, and Modern Coach Factory and user zones is working on this project to track and solve the major obstacles in the way.

While there are trains with bio-toilets running on different routes, Railways has adopted a region-wise approach selecting specific routes where all trains running on tracks are fitted with bio-toilets. The track near Rameswaram is ready. Others include one to Dwarka, Katra and Porbandar, the birthplace of Mahatma Gandhi.

“We chose certain sections of tracks where there were lesser number of trains to make entire tracks free of human waste,” said Kumar.

Additionally, Railways is also putting in place vacuum suction systems at intermediate stations to suck out any material stuck in the valves in these routes. Then there is the challenge of finding enough funds for the project, particularly for the Railways which has massive competing demands on its limited funds. “Each toilet costs about Rs 80,000. The vendors who provide the bacteria colony have to be approved by DRDE. Vendors for the toilet fitments are approved by the Rail Coach Factory,” shared Kumar.

Railways is trying to get some funds from the Swachh Bharat cleanliness kitty which the Centre collects through Swachh Bharat Cess on provision of goods and services including train tickets. “At present, Railways dips into its depreciation reserve fund or the safety fund as use of these toilets also lower corrosion of tracks,” S Mookerjee, Financial Commissioner, Railway Board, had earlier told Business Line.

That said, even if Railways is able to overcome the technological, time and financial challenges, successful implementation of the project also significantly lies in the hands of the passengers — the people of India.

Published on June 07, 2016
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