HMDA says water treated from upgraded STP can be used for non-potable purposes
After suffering the onslaught of pollution for decades that robbed its once pristine glory, rejuvenation seems to be a year away for Hussainsagar lake.
For the 450-year-old water body in the heart of the city, a series of Interception & Diversion (I&D) structures and Sewage Treatment Plants (STP) commissioned recently have come to help improve the quality of water that flows into it. The Hyderabad Metropolitan Development Authority (HMDA) which has taken up the project to clean the water body with Rs.370 crore JICA assistance, described the water treated from upgraded STP at Khairatabad now as being of ‘superior quality fit for reuse for non-potable purposes’.
The lake has four inlets, Banjara nala, Picket nala, Kukatpally nala and Balkapur nala, which together account for an average inflow of around 71.43 million litre per day (MLD). While Kukatpally nala on an average brings in around 29.06 MLD, around 20.39 MLD flows in from the Picket nala.
The existing STP at Khairatabad has been upgraded to tertiary level with biological nutrient removal process to address the issues of nitrates and phosphates and the treated water then undergoes ultra-filtration by membranes procured from Australia. According to HMDA officials, these membranes were being put to use for the first time in the country. “After the ultra-filtration, the water is disinfected of pathogenic bacteria which make the treated water discharged into the lake fit for reuse for non-potable purposes,” said an official. Setting up an additional RO Unit (reverse osmosis) could also enhance the quality to potable purposes, it was suggested.