Above: The demineralisation of water has become a major issue with RO technology/Photo: Representative Image/ youtube.com
Many urban households have installed RO water purification systems to ensure a supply of potable water. The green court has questioned the efficacy of some systems and taken note of water wastage
By Papia Samajdar
For most urban dwellers, Reverse Osmosis (RO) purified water equates with safe drinking water. However, the safety bubble is about to burst. Last May, the National Green Tribunal (NGT) issued an order to ban RO purifiers if the total dissolved solid is less than 500 mg/litre. The bench headed by Justice Adarsh Kumar Goel said in its order that the use of RO systems in areas where the Total Dissolved Solids (TDS) is lower than 500 mg/litre is not only unnecessary but also harmful.
RO is a water treatment process which removes contaminants from water by using pressure to force water molecules through a semi-permeable membrane. During this process, the contaminants present in water are filtered out. RO purifiers are effective in cleaning contaminants. However essential minerals like iron, calcium, manganese, fluoride are also removed.
“The use of RO in water where the TDS is below 500 mg/litre may lead to weakened bones and related problems after a certain age, as researchers have found out,” said Ranjan Panda, convener of Water Initiatives Odisha (WIO), an NGO working on water and climate change issues.
The NGT order also pointed out that about 80 percent of potable water was being unnecessarily wasted and directed the Ministry of Environment, Forest and Climate Change to prescribe a set of conditions for RO system manufacturers to ensure that the recovery of treated water is at least 60 percent, which should be eventually enhanced to 75 percent. The green court also impressed upon the need to use RO wastewater for cleaning utensils, washing, gardening, flushing, and so on.
The NGT order was in response to a case filed in 2015 by Sharad Tiwari, general secretary of a Delhi-based NGO. In his petition, he requested that RO purifier companies should be regulated as they were responsible for water wastage. “This is especially alarming in water-deficient regions and conservation of potable water is crucial to prevent water crisis,” he said in his plea.
The NGT order was based on the recommendations of an expert committee. The report said that RO technology is generally not required for places receiving piped water supply through municipalities. As most people are unaware of the technicalities involved, the NGT ordered that the government spread awareness about the ill-effects of water without essential minerals.
Most experts in the field have supported the order. “This is a welcome judgment,” said Panda, adding, “however, I have my doubts whether it can be implemented the way it is needed. Especially because RO filters have got a huge market push and already entered into people’s psychology in a big way. The way water contamination has shot up, people who can afford RO filters don’t want to take any risk.”
He added: “But the problem is that misinformation has been spread by RO manufacturers and there is absolutely no counter awareness by the government or authorities who supply water. People don’t know about contamination in a water supply system until a public health emergency erupts. There is no way a person can know the water quality at the point of use unless he has a handy testing equipment. Currently, we don’t have any such equipment available at low cost.” RO manufacturers, represented by Water Quality Indian Association (WQIA), without disputing the wastage issue, claimed that 98 districts in 13 states required these purifiers to ensure safe drinking water.
The implementation of the order seems questionable as the ministry is yet to notify the ban. The NGT on November 4, 2019, questioned the ministry’s inaction in carrying out the order. The ministry had requested eight months’ time for effective compliance in a September 2019 hearing. This is procedural time required for any notification, claimed the ministry in its affidavit. The NGT denied the request, calling it unreasonable and detrimental to public interest.
According to the status report filed by the ministry, it had asked CPCB to frame a holistic policy for the use of RO technology in the country and submit a draft notification, which is still to see the light of day. Since issuing a notification is a policy-related matter, a detailed region-wise consultation would be required before the notification can be implemented, the ministry stated.
The Tribunal, however, was in no mood to relent. It slammed the ministry for the delay, asking for its reason for non-compliance. It gave the ministry a final chance to comply by the end of the year, failing which officials would be liable for coercive action.
Dr Suresh Rohilla, director of the water and Wastewater team at the Centre for Science and Environment, said that the Delhi Jal Board (DJB) carries out sample water testing at each of its water treatment plants and also tests 100+ random samples across the city to check if water quality is being maintained. “DJB claims to supply water as per WHO standards,” said Dr Rohilla. The DJB had collected 545 samples from across eight zones in Delhi where it supplies piped drinking water. Of those, 27 samples did not meet all the levels, but 518 samples met all the WHO criteria.
“We do have RO purifier in our home, but I do not mind drinking on the tap water. We have water supply from DJB and it is usually safe enough to drink. The RO purifier came when we bought the house, I don’t think I would have bought it separately,” said Pavitra Goel, vice president at a manufacturing firm. Reena Devi, a resident of Green Park, New Delhi, said, “Until 2017, we were drinking water from the tap, as water was supplied by DJB. However, I suffered from recurring stomach infection, which the doctors suspected was due to water contamination. This is when my family installed the RO. We did a fair amount of research before buying a water purifier.”
Ramesh Kumar, a technician with a leading RO purifier manufacturer, said: “We measure the TDS of the water supply and set the RO machine accordingly. The technology itself has advanced. Our latest machines are equipped to add extra minerals to the water, to compensate for the loss.” Panda believes that “boiled water and simple filters can help but the kind of contamination our water sources are exposed to makes it difficult for the common people to understand what to do. Unless we stop water contamination at the source, things are going to be really difficult”.
The other problem is wastage of water. It is estimated that by 2020, 21 major cities will run out of groundwater. India ranks 120th among 122 countries in the water quality index. Given the situation, we need to know that our water sources are safe and ensure that the wastage is curbed.