In a bid to regulate the use of RO purifiers, NGT has directed the government to prohibit them where total dissolved solids (TDS) in water are below 500 mg per litre and sensitise 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 1200 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.
A bench headed by NGT Chairperson Justice Adarsh Kumar Goel passed the order after perusing a report of a committee formed by it, and gave the directions to the Ministry of Environment and Forests (MoEF).