Keen on saving 17 million litres per day (MLD) of treated sewage water from draining into the sea, the Puducherry government has made it mandatory for all government offices in Puducherry to use treated water for toilet flushing and watering gardens, among other non-potable purposes.
The Public Works Department (PWD) has laid pipelines from its Sewage Treatment Plant (STP) in Dubrayapet for use of the ultra-filtered water for gardening in Bharathi Park and the Government Botanical Garden, located in the Boulevard.
The notification for reuse of Secondary Treated Effluent Water (STEW) for government offices will be formally released by Lt. Governor Tamilisai Soundararajan and Chief Minister N. Rangasamy on Wednesday, December 20, 2023.
According to PWD Secretary D. Manikandan, “The decision has been taken to ensure that no drinking quality water is used for non-potable purposes. Owing to over-exploitation of groundwater, the water level has depleted to a great extent in Puducherry. To overcome the shortage of water for different purposes and to avoid over extraction, the Government has decided to reuse water up to a certain quantity, after proper treatment, for non-potable purposes.”
“An ultra filtration unit has already been installed at the 17 MLD STP in Dubrayapet and the treated water confirms to the standards prescribed by the Central Public Health and Environmental Engineering Organisation (CPHEEO). The treated water is chlorinated and the Biological Oxygen Demand (BOD) was found to be 3 mg/litre as against the permissible 6 mg/litre,” he said.
Initially, the PWD has decided to use about 50,000 litres per day of treated sewage water for horticulture in the Bharathi Park, the Government Botanical Garden and government offices located near Dubrayapet. By using treated effluent, around 50,000 litres of groundwater per day will also be saved, making this an environmentally sound practice. There are no issues like quality or smell as the water is thoroughly chlorinated and meets all parameters, Mr. Manikandan said.
All government offices have been directed to utilise the ultra filtered water from Dubrayapet STP to the maximum extent possible and to recommend all stakeholders under their control for efficient use of treated sewage so as to conserve water. The executive engineer of the public health division of PWD has been appointed as the nodal officer for this purpose, an official said.
The PWD is also coming up with a waste water management policy, aimed not only at treatment of water but also its utilisation. As part of the policy, the PWD would be closing all open drains and shifting to underground drainage in the city.
