TDS levels below 500? Government won't let you install water RO- Here’s why

The green panel had earlier said that the wastage of water in use of RO purifiers merely for advancing the commercial interest of companies needs to be checked.

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New Delhi: The National Green Tribunal has directed the Central Pollution Control Board (CPCB) to issue directions to all RO manufacturers banning water purifiers where the level of total dissolved solids (TDS) in water is below 500 milligrams per litre.

A bench headed by NGT Chairperson Justice Adarsh Kumar Goel also asked the CPCB to issue directions on management of RO rejects, including cartridges.

"To secure compliance of orders of this Tribunal read with an order of the Supreme Court, we direct CPCB to issue an appropriate order under Section 5 of the Environment Protection Act, 1986 in terms of orders of this Tribunal to all the manufacturers so as to come into force within one month," said the bench also comprising Justice Sudhir Agarwal and expert member Dr Nagin Nanda.

The tribunal said gazette notification issued by the MoEF on 'Regulation on use of Water Purification System' cannot be said to be in compliance of its order.

"The Notification seeks to amend Rule 115 of Environment (Protection) Rule, 1986, Schedule I to the effect that all users of Domestic Water Purification System and other DWPS shall comply with the guidelines issued by CPCB.

"There is no provision for regulating and prohibiting RO systems where TDS is less than 500 mg/l, as directed by this Tribunal. There is also no supply chain management of the RO reject. Similarly, water wastage issue remains unaddressed," the bench in its December 1 order said.

The NGT clarified that the CPCB order will be independent and uninfluenced by the Notification issued by the Ministry of Environment and Forests (MoEF).

The green panel had earlier said that huge wastage of water in the use of RO purifiers merely for advancing the commercial interest of companies at the cost of public interest needs to be checked.

It had directed the MoEF to issue notification without delay banning RO purifiers where the TDS level in water is below 500 milligrams per litre.

"The MoEF may issue appropriate notification prohibiting use of RO where TDS in water is less than 500 mg/l and wherever RO is permitted, a requirement is laid down for recovery of water be more than 60 per cent. Further provision be laid down for recovery of water up to 75 per cent and use of such RO reject water for purposes such as utensil washing, flushing, gardening, cleaning of vehicles and floor mopping," the NGT had said.

In a bid to regulate the use of RO purifiers, the NGT had directed the government to prohibit them where TDS is below 500 mg per litre and to sensitise the public about the ill-effects of demineralised water.

The tribunal has also asked the government to make it mandatory to recover more than 60 per cent water wherever RO is permitted across the country.

TDS is made up of inorganic salts as well as small amounts of organic matter. As per a WHO study, TDS levels below 300 mg per litre are considered to be excellent, while 900 mg per litre is said to be poor and above 1,200 mg is unacceptable.

Reverse Osmosis (RO) is a water treatment process that removes contaminants from water by using pressure to force molecules through a semipermeable membrane.

The order had come after perusing an expert committee report which said that if TDS is less than 500 milligrams per litre, a RO system will not be useful but will result in removing important minerals as well as cause undue wastage of water.

The tribunal was hearing a plea filed by NGO Friends seeking conservation of potable water by preventing its wastage on account of unnecessary use of RO systems.