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
Nearly 700 scientists quit DRDO in six years: Govt
AI Express sacks 1 employee, action against 3 others
Quota bill faces opposition from BJP, SP in Lok Sabha
Vinay Kumar ruled out of T20s, Mithun in
Pratyush Kumar to head Boeing India