NGT Demands Sewerage Network Update on 30 Streets Around Puzhal Lake

The southern bench of the National Green Tribunal (NGT) has directed the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) to submit an updated report on the status of underground sewerage connections across 30 streets around Puzhal Lake, noting that no progress report had been filed since January 2025.

The bench, comprising Justice Pushpa Sathyanarayana and expert member Prashant Gargava, issued the directions while hearing a suo motu case initiated following a report published in December 2023 regarding encroachments and waste pollution along the rear bund of Red Hills Lake.

According to a report submitted by the CMWSSB in January 2025, underground sewerage facilities were unavailable in 30 out of 110 streets in the area, covering 628 premises. The board stated at the time that a Detailed Project Report (DPR) was under preparation to extend the underground sewerage system (UGSS) to these uncovered localities.

The CMWSSB report noted that sewage collected from existing collection networks was being routed to pumping stations located at Iyyankulam, Karukku, and Korattur before being pumped to the Kodungaiyur Sewage Treatment Plant. However, the bench pointed out that authorities had not provided any progress updates regarding the completion of the UGSS in the 30 streets since January 2025.

In a separate report submitted in June, the Tamil Nadu Pollution Control Board (TNPCB) stated that it had issued a show-cause notice to the Greater Chennai Corporation (GCC) Zonal Officer for Zone VII and the CMWSSB Superintending Engineer for Zone VII, seeking an explanation on why an environmental compensation penalty of ₹3.45 crore should not be imposed.

The TNPCB directed the CMWSSB to ensure that 100% of households in Kallukuppam, Banu Nagar, Pudur, and Venkatachalam Nagar are linked to a functional UGSS within three months. The pollution control body warned that further delays would be treated as wilful negligence and could result in additional environmental fines. It also mandated that untreated or partially treated sewage and sullage must not be discharged into Puzhal Lake or other nearby waterbodies under any circumstances.

The NGT bench also instructed the GCC to submit an updated report, noting that the civic body last filed one in 2024. The Avadi City Municipal Corporation had also failed to file a report despite the TNPCB levying environmental compensation. The tribunal warned that if the Avadi City Municipal Corporation and the Tiruvallur District Collector fail to submit their reports before the next hearing, each report will be accepted only upon payment of ₹50,000 as costs. The case has been posted for hearing on October 5, 2026.