The Supreme Court on Friday refused to change the National Green Tribunal order, which prohibited use of Reverse Osmosis (RO) filters in Delhi areas with Total Dissolved Solids (TDS) values less than 500 per litre.
The NGT had approached the government to regulate the use of water purifiers and inform people about the negative effects of demineralised water.
RO filters are not required in areas where TDS is low and the system wastes around 80 per cent water as well. The tribunal has asked manufacturers to ensure that at least 60 per cent water is recovered.
Who needs a RO filter?
- The NGT determines that RO water purifiers are required only when TDS value is greater than 500. You can measure this using a TDS meter (costs Rs 150-300) or asking a water purifier company to test your water.
- Ideally, municipality water is low on TDS and doesn’t require RO purifiers. If you get water from a borewell, you need to test it. Municipal water in Cuttack and Bhubaneswar has TDS values ranging between 70-120 according to our tests.
Isn’t RO water extra safe?
No, reverse osmosis removes essential minerals as well. Plus, RO systems waste water by rejection and are hence damaging to the environment.
If not RO, then what?
Experts suggest using normal UV based water purifiers or BIS approved candle based ones if your TDS value is less than 500.
