Rail coaches built after 2016-17 will have bio-toilets and by 2020-21 all trains will have such toilets, Railways Minister Pawan Kumar Bansal told Lok Sabha on Thursday.
The bio-toilets, which have been indigenously developed by Indian Railways and DRDO, have been installed for in-service trials in nine trains, he said during Question Hour.
"By 2016-17, all new coaches built in the country will have bio-toilets. By 2020-21, all coaches will have bio-toilets," Bansal said.
He said such toilets are being installed in existing coaches through retro-fitment but the process costs five times more than building new coaches with bio-toilets.
"The estimated cost of retro-fitment in existing coaches is expected to be approximately Rs 15 lakh (Rs 1.5 million) per coach while in case of original fitting in the new coaches the cost will be about Rs 300,000 per coach," he said.
The quantum of work and material required in case of retro-fitment is significantly more which makes it a costly affair. Rs 7,000 crore (Rs 70 billion) would be required for this project, Bansal said.
Gwalior-Varanasi Bundelkhand Express is the first train to have a bio-toilet.