"At present we will only look into the aspect whether the people living in railway colonies and passengers at platforms and stations are made available good quality of water or not.
"Let samples be collected from different divisions of the Northern Railway and report be filed before the court," a bench of Chief Justice G Rohini and Justice Jayant Nath said.
The bench also sought to know about the status of the functioning of the chlorination plants and said it would issue directions to the authorities in its detailed order.
The court was hearing a PIL, filed through advocates Prashant Bhushan and Govind Jee, which sought "an independent and preferably court-monitored probe into the neglect of the quality of the drinking water supply, and the manipulations in the award of contracts for supply of chlorination plants for past several years."
The petitioner NGO CPIL has contended that while the Indian Railways, having an independent water supply system all over the country, is able to keep trains running by meeting the requirement of water for washing and cleaning of trains, tracks and platforms, it is "failing to supply safe and wholesome drinking water to millions of railway passengers and its staff who live in the railway colonies".