The Environment Ministry’s draft notification to regulate the use of membrane-based water purification systems primarily concerns the manufacturers of reverse osmosis (RO) water filters but effectively bars domestic users from installing RO systems
- The association of water filter manufacturers challenged this order and the litigation led to this pan-India notification, where the intent is to conserve water and cut waste.
- In RO, the total dissolved solids (TDS) in water — which covers trace chemicals, certain viruses, bacteria and salts — can be reduced, to meet potable water standards.
- Home filters waste nearly 80% of the water during treatment.
- Notification implies, these filters are only prohibited if the home gets water supply that conforms to Bureau of Indian Standards (BIS) for Drinking Water.
- The BIS, last year, ranked several cities on official water supply quality.
- Delhi was last and only Mumbai met all the standards.
- In the 28 test parameters, Delhi failed 19, Chennai 9, and Kolkata 10. The BIS norms are voluntary for public agencies which supply piped water but are mandatory for bottled water producers
- The Composite Water Management Index (CWMI) of NITI Aayog says that 70% of water supply is contaminated.
- India is ranked 120th among 122 countries in an NGO, WaterAid’s quality index.