DJB says RO purifiers not needed for water supplied by it

The Delhi Jal Board Thursday claimed water supplied by it does not need to be treated by reverse osmosis purifiers and is "fit enough" to drink straight from the tap.

The utility's claim comes after the National Green Tribunal (NGT) Tuesday directed the government to prohibit the use of RO purifiers where total dissolved solids (TDS) in water were below 500 mg per litre.

TDS is made up of inorganic salts and 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 treatment process that removes contaminants from water by using pressure to force molecules through a semipermeable membrane.

"RO purifiers are not required for water supplied by the DJB. It is fit enough to drink. We follow the guidelines set by the WHO and keep the TDS content between 100 and 200 mg per litre and pH value between 7 and 7.8 within permissible ..