There is little doubt that due to RO water filters sold to millions of houses in India, large amount of drinking water goes in the drain.
If I recollect rightly, Green Tribunal too had issued notices to authorities to explore a solution. I am not aware about further state of the case.
So far as I am concerned, one day I noticed that about 120 LTR of drinking water was per day wasted in my house.
I bought a TDS meter from Amazon. I found that TDS was less than 150 in incoming water before it was filtered.
So there was no need for RO filter. I called a repair man, who converted RO Water Unit into Ultra Violet Rays filter unit.
Immediately, I began to save 120 ltr of drinking water per day.
I think in major parts of India, RO water filters are not necessary. But they are sold as sign of riches to people by marketing and advertising people.
I think laws can be improved in this area.
Haresh Raichura 8/10/17