Hon’ble National Green Tribunal (NGT) in O.A. 134 of 2015 titled ‘Friends through its General Secretary versus Ministry of Water Resources’ vide its order dated 20.05.2019 directed that Ministry of Environment, Forest and Climate Change (MoEF&CC) may issue appropriate notification prohibiting use of Reverse Osmosis (RO) where Total Dissolved Solid (TDS) in water is less than 500mg/l. NGT further directed that wherever RO is permitted, a requirement be laid down for recovery of water to be more than 60%.