The Railways are facing technical hitches in installing environment-friendly bio-toilets in trains, forcing an extension of the deadline for implementation of the project.

All new passenger coaches will have bio-toilets by 2016-17, but retrofitting of the existing coaches are expected to be completed by 2021-22. The Ministry of Drinking Water and Sanitation will fund 50 per cent of the retrofitting cost of two lakh units in the existing 50,000 coaches.