Railways needs a bug to keep toilets clean

A few years ago, a scientist from Defence Research and Development Organisation (DRDO) visited India’s research outpost in Antarctica. Fascinated by a strain of bacteria, psychrophiles, that ingest human waste and convert it to odourless water at subzero temperatures, he brought the bacteria with him to India. Scientists at DRDO used it to develop bio-toilets.

Bio-toilets were tested before being adopted by the military, which now uses them in the Siachen heights.

Around the same time, Indian Railways was being roundly criticised for creating an environmental hazard by discharging toilet waste on tracks. The environment ministry was unhappy with trains polluting lakes and rivers, as studies showed that trains crossed a large number of water bodies.
Indian Railways and DRDO thus came together to develop bio-toilets for trains. The railways had experimented with other options at considerable expense, but they had all failed.

“Somebody suggested that anti-corrosion paint was the best option to prevent corrosion of tracks and undercarriages of coaches,” said a Southern Railway official. “We spent crores on paints but they made no difference to the corrosion rate. Undercarriages needed to be replaced every four years as earlier. An official then proposed a controlled discharge.”

The controlled discharge toilet used a sophisticated system that used GPS. It collected waste in a box and discharged it automatically when a train picked up speed. The GPS system monitors if the train is over a water body or at a railway station to prevent polluting water bodies and keep terminals clean. It was considered an interim arrangement till a permanent solution was found.

“It looked good on paper but the GPS system did not work well,” the Southern Railway official said. “The toilet system often got jammed by bottles and garbage that travellers dumped in the commodes. It created a problem for rail yard workers who had to pry open toilet boxes and empty the waste into pit lines. The yards soon got polluted and posed a serious health hazard to employees.”

Controlled discharge toilets were also expensive, costing around 6 lakh per piece. Malfunctioning toilets threatened to derail train schedules especially at large terminals like Chennai, where more than 30 rakes have to be cleaned and overhauled every day. Railway staff have just six hours to make sure a rake is fit to be used. It was not possible to spend additional time to set right faulty toilets.

The railways then experimented with zero discharge toilets. They were developed by IIT-Kanpur and Research Design and Standards Organisation (RDSO) to segregate solid waste and liquid waste, recycling the liquid waste to be used for flushing. Solid waste was treated with anaerobic bacteria and stored in a box that was emptied at stations or yards. This toilet was found to be successful on a long-distance train. But sources said zero discharge toilets need more tests. “The systems provided varied results during trials,” a railway official said. “Removing solid waste from tanks was a problem. Vacuum machines are prone to technical glitches.”

Officials of RDSO had suggested in 2005 that railways switch over to vacuum toilets, which are used extensively in the West, for premium services. But it realised they would require expensive support infrastructure at stations or yards.

“We tried different options including zero discharge toilets and vacuum toilets,” said Indrajit Singh, executive director of RDSO. Railways is now cautious. “We have to consider what passengers feel about a certain type of toilet. On average, more than 80 people use three Indian style toilets in each coach of a train in less than 20 hours,” another official said. “Tests have demonstrated that bio-toilets can be used by a large number of people. We are continuing tests to see if they have any shortcomings and to see if there is any change in the behaviour of the bacteria,” an official said.

Bio-toilet treats waste with multiple levels of bacteria,
converts it to water and gas
Bacteria ingests fecal matter, turns it into slurry
When toilet is flushed,
treated waste flows to where it is converted into water and disinfected with chlorine
Water and gas goes to the lowest tray where it is filtered and expelled when the train is travelling at 30kmph
THE GOOD | Converts waste to water that, when expelled, does not corrode tracks
THE BAD | Bacteria may not work if passengers chucks things in toilets. If toilets are overused, bacteria will not be able to convert all the waste into water and gas ZERO DISCHARGE
Waste not dropped on tracks. Toilets segregate solid and liquid waste with solidliquid separators and store it in tanks. Liquid waste recycled for flushing
Separator does not need
power to operate
Microbials added to prevent decomposition. Can be stored for 10 days before being removed with vacuum machine
Liquid filtered twice to remove sediments, to tank in undercarriage of coaches, used to flush toilets
THE GOOD | Does not discharge on tracks, prevents corrosion. Water reused to flush, keep toilets clean. Toilet does not get clogged by bottles and garbage
THE BAD | Worked well during trials, but more tests needed.


Railways to try anaerobic bacteria and vacuum technology in toilets

Toilets in Indian Railways coaches will soon witness a makeover. The idea is for the conventional open lavatories to be replaced with squeaky clean ‘green toilets’.

For the railways, waste management is a major task, as it handles about 10 million long-distance travellers every day. This year, the railways will install bio-toilets in about 2,500 coaches.

The cost of doing so is expected to be around Rs 500 crore. Rural Development Minister Jairam Ramesh has offered to share half the cost of equipping all new railway coaches and retrofitting all existing coaches with bio-toilets built by the Defence Research and Development Organisation (DRDO).

Indian Railways is also planning trials on vacuum toilets, similar to those used in aircraft. With this, the railways hope to offer an airline-like experience to commuters.

A senior rail official told Business Standard a global tender for 80 vacuum toilets for 40 coach sets, along with ground handling facilities at New Delhi, was under consideration.

A total of 68 bio-toilets based on anaerobic bacteria, imported from the US, and 436 bio-toilets based on anaerobic bacteria and developed indigenously by DRDO are already in operation in nine trains.

In the bio-toilet system, anaerobic bacteria consume the waste material and convert it into water and gas. The water passes through a chlorine tank and is discharged as clean water, while the gas generated evaporates. The technology used has been developed by DRDO, and is not used in any other railway system in the world.

“Based on the outcome of the trials, these bio-toilets will be fitted in the other trains. The timeframe for full implementation will depend on the outcome of the trials,” said the official.

The technology is not without its share of problems. As the bacteria can only decompose human waste, throwing plastic, polythene and napkins in the bio-toilets could affect the working of the system, the official informed.

A committee has been constituted to study the fitment of bio-toilets on existing coaches. The railways have an estimated 50,000 coaches. About 4,000 coaches are produced every year, which could be fitted with bio-toilets.

The other technology being used in the coaches of Rajdhani, Shatabdi and Duranto trains is the controlled discharge toilet system (CDTS). In this, the toilet holds the contents until the train attains a speed of 30 kmph, after which the discharge takes place. The idea is to prevent the toilet from releasing contents at stations. So far, 5,300 CDTS units have been provided in 1,900 coaches, built under transfer of technology imported from Germany. “We are using CDTS technology in which discharge takes place outside the station. But, it only shifts the problem from the station area to an area outside station limits,” admitted a railway official.


Bio-toilets in all trains in phases

Railway track and stations will be cleaner in the days to come, with the railways deciding to install bio-toilets in all coaches in a phased manner. It, however, cautioned that the success of the project would depend upon the cooperation and discipline of passengers.

The decision comes close on the heels of an offer made by the Rural Development Minister Jairam Ramesh to share 50 per cent of the cost from the budgetary allocation of the Ministry of Drinking Water and Sanitation. The offer pertains to retrofitting bio-toilets that the railways have developed jointly with the Defence Research and Development Organisation (DRDO) in 50,000 passenger coaches.

For this, about two lakh units will be required. Bio-toilets will be built in new coaches and the railways will bear the cost themselves. Retrofitting of bio-toilets will also involve the DRDO and the Ministry of Drinking Water and Sanitation. The railways will bear 50 per cent of the cost.

In bio-toilets, the waste is converted into water and gases — methane and carbon dioxide. The waste will be treated by bacteria, which are benign to humans. While the gases get released into the atmosphere, the water will be discharged after chlorination. By completely eliminating the fall of human waste on the track, bio-toilets will help in checking depreciation of coaches and track by preventing corrosion.

During field trials, it was found that passengers used the bio-toilet as a garbage bin. The toilets were blocked by various objects rendering the system non-operational. Plastic bottles, tea cups, cloth, sanitary napkins, poly bags and gutka pouches, among other articles, were found in the toilet pans.


Railways Rs 500cr plan for green toilets on passenger trains

Railways has taken up a Rs 500-crore plan to equip its passenger coaches with environment-friendly toilet system. The project cost is being shared by the rural development ministry to improve hygiene in toilets on trains.

The railways had earlier signed an MoU with the Defence Research and Development Organisation (DRDO) to develop such a toilet system.

According to a Railway Board official, railways has given directives to its coach manufacturing factories at Kapurthala in Punjab and Perambur in Tamil Nadu to manufacture new coaches fitted with green toilet system. Railways has taken a decision to convert old toilets into green toilet system in about 50,000 coaches across the country, he said. A board official said the railway coach manufacturing factories have so far built such green toilets in about 436 new coaches to cater to the needs of passengers. Railway coach factories have been manufacturing about 4,000 new coaches per year.

Railways intends to introduce such toilets in all long-distance passenger trains on a priority basis, he said.

Sources said the DRDO has designed the new green toilet system in consultation with railways and rural development ministry with the main objective of developing this system to maintain zero discharge toilet system (ZDTS) on running trains. The new toilets are aimed at providing homely comforts to passengers during long journey, sources said.

A board official admitted that a green toilet-fitted train was put on trial recently on a particular route under Northern Railway which evoked good response among passengers.

Meanwhile, railways has also decided to introduce a new system on select long-distance trains. Under the new experiment, railways is likely to provide phenyl-like substance to passengers to ensure hygiene in toilets on running trains.

This experiment will start with all Duronto trains, sources said, adding railways will introduce this system depending on passengers’ response. Confirming it, a board official said that the new system is being tested in South Eastern Railway first.

Kerala gets its first train with bio-toilets

Kerala will have the first train in Southern Railway which have bio-toilets fitted on all its compartments. The new rake which arrived at Kochuveli terminus in Thiruvananthapuram last week, will be one of the trains running between the state and Bangalore as Kochuveli-Bangalore express, once, the now triweekly, becomes a daily service.

Senior divisional mechanical engineer, Venugopal told TOI that the effort was not part of any trial exercise and it would be the first environment friendly train in Kerala and Southern Railways.

“The bio-toilets employ anaerobic bacteria provided by the Defence Research and Development Organisation (DRDO), to deal with the faecal waste produced on board the train. While existing toilets in trains just flush the human waste on to the tracks, this train has a tank fitted underneath all the toilets, which will collect the waste.

“The bacteria in the tank will break down the waste and the residue would be just waste water. The technology has been under trial for many years and has been approved. This will be one among the few trains in India which will boast of bio-toilets,” Venugopal said.

The official said that a layer of cow dung would be put inside the container to facilitate the fast growth of bacteria.

“If properly maintained we would not require a re-shot of bacteria for 18 months. The mechanical department would also conduct regular sample testing of waste water to ensure pollution levels.

“While some trains running in SR has employed bio-toilets on trial basis, this is the first time a full rake is getting fitted by the green toilets in the zone. It is part of Indian Railways effort to stop the decade old procedure of flushing waste on tracks,” Venugopal further said.

The 16315/16316 Kochuveli-Bangalore-Kochuveli express was supposed to become a daily service from July 1. However it was stalled, after railway passengers protested the change of timings. Currently, a decision regarding this is pending before the railway board.


• Faecal waste collected in a tank and treated before discharging it

• Anaerobic bacteria provided by DRDO used to treat the waste

• The residue is just harmless waste water

• One shot of bacteria can serve up to 18 months

Train with bio-toilets chugs in

The 24-coach green train with bacteria-eating bio-toilets finally arrived in Mumbai this week. The Varanasi-Mumbai train with bio-toilet technology, jointly developed by the Defence Research and Development Organisation (DRDO) and railways, arrived from Rail Coach Factory earlier this week.

The train aims at zero defecation on the ground and the waste is eaten by bacteria and converted into gas and water.

Part of the project by the railways to improve hygiene standards in and around tracks and station area, the toilets are designed keeping in mind Indian needs like long-distance travel and toilet habits.

“Currently, train toilets are of direct discharge type. As the number of trains increases, open discharge of waste grows into a bigger problem, with human waste from trains leading to track corrosion and making it difficult for gangmen to walk them for repairs,’’ a senior official said.

Till March 2012, the Indian Railways have set a target to turn out five rakes with 300 bio-toilets by Rail Coach Factory and former railway minister Dinesh Trivedi mentioned so in his rail budget speech too.

Controlled discharge toilet system fitted in some CR trains discharges waste only after train acquires speed more than 30 kmph.

A senior official said the retention tanks in train’s toilets will store the waste empty it at terminal stations into sewage lines, not dropping the waste all along the tracks. The solid and liquid waste will be separated in the tank, while liquid will be recycled and used, a bacteria will disintegrate the solid waste.


Railways keen on using Kaveri engines developed by DRDO

The Indian Railways has shown keen interest in the Kaveri engine, which is being developed for fighter aircraft, to power its trains, the Defence Research and Development Organisation (DRDO) has told a Parliamentary Committee.

“A request has come from the Indian Railways to know that whether Kaveri engines can be used for powering locomotives,” DRDO told the Standing Committee on Defence.

In its report tabled in Parliament last week, the Committee said the DRDO has plans of producing Kaveri engine in large number in collaboration with Bharat Heavy Electricals Limited (BHEL).