As if the state’s groundwater depletion due to paddy was not enough, Punjab Pollution Control Board (PPCB) has expressed concern at the indiscriminate installation of reverse osmosis (RO) systems in the state, even though 75% of water being supplied in 16 key cities is potable.
The PPCB chairman, K S Pannu, told TOI that data collected by the board shows that most of the groundwater in the state has almost all key parameters within permissible limits for drinking purposes and can be considered potable. “The households using RO systems end up wasting three to seven times drinking water in form of RO reject, which increases load on sewage treatment plants and also causes excessive ground water exploitation,” he said.
“However, of late, people in the state have begun using RO systems to purify water and without it water is not considered clean. They don’t realise that RO water has its own challenges and this aspect is not considered. Experts at various medical colleges and universities in the state have underlined this fact,” said Pannu.
Dr Naresh Kochar, former professor of geology, Panjab University, too said, “There is a lot of wastage of water through RO system in most cities of Punjab, except south-west of the state, even though the quality of water supplied by the municipal corporation is good and there is no need for RO systems at home and offices. It leads to wastage of precious water and also causes health problems,” he said.
Endorsing the PPCB’s view, Government Medical College, Patiala, has observed that palatability of water with total dissolved solids (TDS) level of less than 600 mg/litre is generally considered good. It becomes unfit beyond 1,200 mg/litre. But the RO reduces minerals, especially calcium and magnesium in water, and is a source of health problems like weakness of bones. Similarly, Guru Nanak Dev University (GNDU), Amritsar, said there was no need to install ROs for drinking where the TDS level was less than 500 mg/litre. There is huge wastage as RO rejects lot of water into drains. Even water used for back wash of RO is large in quantity, which puts stress on underground water.
The PPCB data shows 75% of groundwater in districts of Gurdaspur, Pathankot, Sangrur, Barnala, Hoshiarpur, Jalandhar, Ludhiana, Kapurthala, Moga, Nawanshahr, Patiala, Fatehgarh Sahib, Ropar, Mohali, Amritsar and Tarn Taran have almost all parameters within desirable limits for drinking purposes. Around 50% of groundwater in districts of Bathinda, Mansa, Muktsar, Fazilka, Ferozepur and Faridkot have good water quality rating. The PPCB has said that according to experts, UV treatment, carbon candle and chlorination can be used as methods of water purification as these do not interfere with the ionic composition of water.