Nine town panchayats in Coimbatore district continue to discharge untreated sewage directly into the Noyyal River, nearly two years after sewage treatment plants (STPs) received federal clearance — with the project still stuck at the planning stage as of 4 August. The delay has drawn alarm from farmers and environmentalists who warn of worsening groundwater contamination along the river's course.

Project Background and Approvals

The STP project was sanctioned in 2024 under the Nadanthai Vaazhi Cauvery scheme, following clearance from the National River Conservation Directorate (NRCD) under the Union Ministry of Jal Shakti. It covers nine local bodies — Irugur, Sulur, Kannampalayam, Vellalore, Perur, Pooluvapatti, Veerapandi, Alandurai, and Thondamuthur — all situated along the Noyyal.

The scheme envisages intercepting and treating sewage generated by these town panchayats before it reaches the river. Under the approved funding structure, the Centre is to bear 60 per cent of the total project cost, with the Tamil Nadu government contributing the remaining 40 per cent.

Why the Noyyal Matters

The Noyyal is a significant tributary of the Cauvery, originating in the Western Ghats within Coimbatore district and flowing approximately 158.35 km through Coimbatore, Tiruppur, Erode, and Karur districts before merging with the Cauvery. Roughly 62.21 km of the river passes through Coimbatore district alone, where its water system encompasses 17 dams and 25 ponds.

Untreated sewage discharge from local bodies has long been identified as a primary driver of the river's deteriorating water quality. The contamination also threatens groundwater reserves that farming communities in the region depend upon.

Farmers Sound the Alarm

Rajan Arunachalam, a farmer and member of a non-political farmers' association, said there had been virtually no progress on establishing the STPs since the initial announcement. 'Untreated wastewater continued to enter the river from the local bodies, resulting in groundwater pollution and making farming increasingly difficult in areas along the Noyyal,' he said, urging authorities to implement the project without further delay.

Farmers along the Noyyal have broadly expressed concern that the persistent discharge of wastewater is contaminating groundwater and disrupting agricultural activities — a pattern that has worsened with each passing season.

Where the Project Stands

Coimbatore District Collector Pavankumar G. Giriyappanavar confirmed that a proposal had been forwarded to the state government to extend the project to additional local bodies situated along the Noyyal. He added that the project is currently at the Detailed Project Report (DPR) stage and would be implemented after completion of the necessary procedures.

This comes amid growing scrutiny of the pace of river rejuvenation efforts under the Nadanthai Vaazhi Cauvery scheme. Notably, the Noyyal's pollution problem is not new — successive administrations have flagged it without delivering lasting remediation. With the DPR still pending finalisation, the timeline for actual construction of the STPs remains unclear.