NGT asks Ministry of Environment to ban RO purifiers within two months

A Non Governmental Organization (NGO) seeking conservation of potable water by preventing its wastage on account of unnecessary use of RO systems moved the National Green Tribunal (NGT).

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

The NGT directed the Ministry of Environment and Forests (MoEF) on January 15, 2020 to issue a notification banning RO purifiers, within two months, where total dissolved solids (TDS) in water are below 500 milligrams per litre. The MoEF had sought four months for executing the order of the National Green Tribunal.

NGT Chairperson Justice Adarsh Kumar Goel said that the delay in compliance with its order would cause harm to public health and environment and that the order be complied with expeditiously.

The NGT sought to regulate the use of RO purifiers and therefore directed the government to prohibit them where total dissolved solids (TDS) in water are below 500 mg per litre and make the public conscious about the ill-effects of demineralized water. The NGT also asked the government to make it mandatory to recover more than 60% water wherever RO is permitted across the country.

An expert committee submitted a report stating that where TDS is less than 500 milligrams per litre, the RO system will not be useful but will end up removing important minerals as well as cause undue wastage of water.

TDS is made up of inorganic salts as well as small amounts of organic matter. As per a World Health Organization (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.