Bihar Plans Mega Sewage Treatment Plant in Patna.

Bihar is set to build its largest sewage treatment plant (STP) - a 400 million litres per day (MLD) facility - in Patna, as part of efforts to prevent untreated wastewater from flowing into the Ganga.

Following a review meeting of the Namami Gange in Delhi, the state’s urban development and housing department directed the Bihar Urban Infrastructure Development Corporation (BUIDCO) to initiate the project.

Patna divisional commissioner and BUIDCO managing director Animesh Kumar Parashar said the objective is to ensure that all city drains are “tapped” to stop contaminated water from entering the river untreated. “The process involves intercepting existing drains and diverting them to the STP, where sewage will be treated and processed before being released into the Ganga,” he said.

According to BUIDCO PRO Sweta Bhasker, surveys have been conducted from Digha to Didarganj, with proposed sites identified between Danapur and Patna City. The final location awaits approval from higher authorities. The project design will determine whether the facility will operate as a single 400 MLD unit or two 200 MLD units.

The new infrastructure will link drains in areas including Digha, Kurji, Rajapur, Mandiri, Anta Ghat and Mittan Ghat through an interception-and-diversion system. Officials said the plan aims to minimise public inconvenience by using existing channels and avoiding fresh excavation in narrow streets.

Bihar currently manages 39 STPs with a total outlay of ₹7,752 crore and plans to increase the number to 45. The expansion is aimed at treating nearly 1,100 MLD of sewage generated in towns along the Ganga.

Of the 39 projects, 21 are operational in districts such as Munger, Bhagalpur, Chhapra and Patna. The capital currently runs four plants in Beur, Saidpur, Karmalichak and Pahadi, while facilities in Digha and Kankarbagh are partially functional. Thirteen more STPs are under construction in districts including Motihari, Supaul, Jamui and Rohtas, and are expected to be completed within two years. Five projects in Buxar, Muzaffarpur, Katihar, Arrah and Lakhisarai are in the tendering stage.

Officials said construction and commissioning of such plants typically take about three years. In addition to the proposed 400 MLD Patna facility, five more STPs are being processed in Khagaria, Jamalpur, Barauni, Samastipur and Gaya.

The urban development and housing department has prioritised tapping all major drains to curb untreated discharge into the Ganga and strengthen wastewater management infrastructure across the state.