The BJP government’s plan to clean the Yamuna is likely to hit a roadblock with the National Green Tribunal flagging 17 out of 37 sewage treatment plants (STPs) in the national capital that are possibly releasing faecal coliform bacteria into the river.

Delhi’s environment minister Manjinder Singh Sirsa has confirmed to The Telegraph that 16 out of 37 STPs had failed to meet environmental standards in April.

The Yamuna, which flows through a 40km stretch in Delhi, was a key poll plank in the Delhi Assembly elections in February, with the BJP pillorying the then AAP government for failing to keep its promise to clean the river despite its decade-long stint. As a part of its aggressive campaigning, the BJP had outlined an ambitious three-year plan for the revival of the Yamuna and made it a top priority in its manifesto.

Citing a report by the Central Pollution Control Board, the NGT in its recent order said: “17 STPs are not complying with the norms in reference to the faecal coliform and are possibly discharging the treated water with high faecal coliform in river Yamuna or in some other natural water body or stream.”

Improving and upgrading sewage treatment infrastructure in Delhi was part of the BJP’s clean-Yamuna plan. The party had also promised to construct 40 decentralised STPs to treat wastewater at its source and prevent untreated sewage from entering the river.

Sirsa said two STPs — Okhla and Sonia Vihar — had been completed and were under trial, while another one at Delhi Gate was in the pipeline.

He said the government was prioritising the construction of 40 decentralised STPs, with tenders being invited for 32 of them and land acquisition complete for 38.

Sirsa said all STPs were expected to be fully compliant by June 2027.

Environmentalist Vikrant Tongad said it would take 10-15 years to clean the Yamuna even if all STPs started functioning properly.