ISLAMABAD: The growing use of Reverse Osmosis (RO) systems in households is prompting water quality experts to caution consumers against unnecessarily removing minerals from drinking water and treating an extremely low Total Dissolved Solids (TDS) concentration as a sign of superior water quality. Talking to APP, Director, National Water Quality Laboratory, Pakistan Council of Research in Water Resources (PCRWR), Saiqa Imran, said RO systems were useful where water contained excessive dissolved salts or specific contaminants requiring treatment, but their unnecessary use could remove naturally occurring minerals from otherwise acceptable water. She said a TDS concentration below 100 milligrams per litre, particularly concentration of 20, 30 or even 14 milligrams per litre, should not automatically be considered ideal drinking water. “People often assume that if the TDS concentration is very low, the water is safe and better. This is not correct,” she said. According to her, reverse osmosis removes dissolved substances, including mineral salts, from water. Therefore, where the source water already meets the relevant quality standards and is free from harmful chemical and microbial contamination, unnecessary RO treatment may not be required. APP
