CHENNAI: A new report by the Save Ennore Creek Campaign on Wednesday has revealed that Ennore’s thermal power plants violated air pollution norms or failed to provide valid data nearly 49% of the time during the winter season (November 2024 to January 2025), exacerbating health risks for local communities and raising questions about the Tamil Nadu Pollution Control Board’s (TNPCB) regulatory response.
The analysis, titled 'Breathless in Ennore', studied publicly available real-time stack emission data of three major thermal plants—North Chennai Thermal Power Station Stage I (NCTPS I), Stage II (NCTPS II), and NTECL Vallur, sourced from TNPCB’s CARE Air Centre (CAC).
The findings show NCTPS II had zero compliance, with invalid or missing data 96% of the time, and emissions in the remaining 4% of time exceeding all norms. NTECL Vallur violated sulphur dioxide (SO₂) limits for 80% of the winter, while NCTPS I was non-compliant for 23% of the period.
Durga Moorthy, author of the report, said, “When (on average) 49% of the time, there’s either no reliable data or emissions exceed the legal limit, it means regulators are blindfolded and communities are exposed.”
Chennai’s winter weather worsens ground-level pollution due to temperature inversions, where cooler air traps pollutants close to the surface. According to the report, winter PM2.5 levels in Chennai are 3–40% higher than annual averages. With unregulated pollution in Ennore, the local impact is likely far worse.
Despite earlier assurances under the Manali Ennore Restoration and Rejuvenation Company (MERRC) that a dedicated command centre would ensure real-time emission monitoring and prevent discharge violations, the report notes that neither reliable data nor compliance has materialised. In fact, a court-directed mechanism to monitor violations and take punitive action remains ineffective.
“There are Scheduled Castes, Tribes and Most Backward Communities living here, and we are being treated as expendable,” said A. Bhagath Singh of Namakkana Ennore Iyakkam. “This is environmental casteism.”
The report urges the Tamil Nadu government to hold TNPCB accountable, take strict action against violators, and implement a time-bound airshed management plan for the Ennore-Manali region. With real-time data and legal tools already available, the failure to act now, the campaign warns, will cost more lives.
While the TNPCB CAC claims to have an inbuilt alarm system to inform the concerned industry and TNPCB authorities when emission levels exceed the prescribed standards, environmental activists say occurrences of continuous exceedances suggest that TNPCB has failed to curb critical emission violations.
The southern bench of the National Green Tribunal in a case filed in 2020 directed TNPCB to constitute a dedicated team to monitor the OCEMS data to deal with stack emission violations. The industries were also directed "to create an internal mechanism to closely monitor the functioning of OCEMS as well as critically analyse the data for immediate corrections and submit a monthly analysis report to TNPCB." In a case on ash remediation in Ennore creek, TNPCB was directed to "monitor functioning of NCTPS and take action, including prosecution, if violations are detected."
However, the findings clearly reveal that nothing effective in the direction of compliance or regulatory action has materialised, the report said.