Central Railway experiments with Japan model for saving water in trains

Mini water treatment plant devices installed on Mumbai division CR trains. Pics/Rajendra Aklekar

Central Railway (Mumbai) has become the first division of Indian Railways to replicate the concept of Japanese Railways' water-saving model. An experiment of installing a mini water treatment device inside trains to recycle water from wash basins and dripping AC unit water for flush tanks has been successful, and the idea saves and limits use of water in tanks of trains on the move.

"As of now, the idea is just a proof of concept. The solutions proposed, even though effective, require proper design philosophy changes during coach manufacturing and periodic overhaul at workshops for aesthetics, ease of maintenance, and optimised space utilisation on large-scale implementation," said Divisional Railway Manager (DRM) Rajneesh Goyal, the brainchild behind the idea.

"It all began following an assessment of complaints on the Rail Madad App, which had several complaints about water non-availability on moving trains. We fill up tanks at particular stations, and the average distance between watering stations is 250 km to 300 km, and if there are train delays and other issues, there are problems," Goyal said.

"The need was to conserve water. We had heard of such experiments, especially on the Japanese Railways, and thought we could try out the concept here. And, on trying it out in one coach, we found that the experiment succeeded, and it will lead to savings of water in the train's tank for a longer time," he added.

How it works

The first step is providing storage tanks for wash basin drains (approx. 80 litres), then connecting the roof-mounted AC units' drainage system pipes to the wash basin drainage storage and also connecting the wash basin drainage storage to the flushing system along with a foot pedal valve.

The proposed system uses a small undercarriage Sewage Treatment Plant (SWP) to recover water before it enters the bio toilet storage tanks and sends it back for flushing. This can be done using smart designs and customised sewage water plants during periodic overhauls at workshops and coach manufacturing facilities for new coaches.

Benefits

The key benefits include water conservation by minimising water waste and promoting a more sustainable approach to sanitation. It is cost-efficient because by reusing wastewater, the system reduces reliance on external water sources, leading to cost savings.

It helps the environment by contributing to a greener approach by reducing the overall water footprint of LHB-class coaches. It is also sustainable by effectively minimising water consumption from the main reservoir.

This system helps reduce passenger complaints, ensuring better resource management. It also helps in cost savings as the scheme is expected to reduce expenditure on costly water storage and filling systems along with manpower.

How it works in Japan

In Japan, train toilets feature a water recycling system where water used to wash hands in sinks attached to the toilet is then reused to fill the flush tank, essentially creating a closed loop for water usage and significantly conserving water.

In India Water shortage in coaches: 1,800 - 1,900 litres
Types of toilets: Indian 3, Western 1
Average distance between watering stations: 250-300 km
Percentage of toilets with vacuum suction: 0.5%
Percentage of water usage in flushing: Approx 40%
Percentage of water usage in wash basins: Approx 60%