The Tamil Nadu Pollution Control Board (“TNPCB”) has issued a Circular under the Air (Prevention and Control of Pollution) Act, 1981 and the Environment (Protection) Act, 1986, directing operators of Diesel Generator (“DG”) sets to adopt specific measures to control emissions and improve air quality across the State. In line with the National Clean Air Programme (NCAP) and the Hon’ble National Green Tribunal’s directives, TNPCB has made it mandatory for all DG sets with a capacity of 61 kW and above to either install a Retrofitted Emission Control Device (“RECD”) or switch to gas-based generation.
The operators must comply with the directions in non-attainment cities viz Chennai U.A. (Urban Agglomeration), Madurai U.A, Trichy U.A & Thoothukudi within 180 days i.e. 26th January 2026 and for other places within 1 year i.e. 30th July 2026.
Background:
Environment Ministry had launched National Clean Air Programme (“NCAP”) for the prevention, control, and abatement of air pollution in the country at an urban and regional level. This plan targets 40% reduction in PM 2.5 and PM 10 concentration in the ambient air or achievement of standards at national level. Central Pollution Control Board had notified System and procedure for emission compliance testing of Retro-fit Emission Control Devices RECD for Diesel Power Generating Set Engines up to Gross Mechanical Power of 800 KW, with an objective for reduction of Particulate Matters by using RECD for in-use diesel operated internal combustion engines up to 800 KW (1000 KVA). Retrofitting emission control devices/equipment in DG sets is one of the key activities included in the Action Plan for Tamil Nadu under NCAP.
Key Highlights:
- Options to Comply:
- Install a CPCB-certified RECD with at least 70% efficiency for particulate matter capture on in-use DG sets aged more than five years and within their useful life (15 years or 50,000 operational hours, whichever is earlier); or
- Shift to gas-based generators or retrofit existing sets for partial gas use or use of Duel fuel system for in-use DG sets of less than 800 kW capacity up to its useful life as mentioned above; or
- Replace with gensets compliant with updated emission norms; or
- Adopt any other emission control mechanism, strictly subject to compliance of notified emission standards for sets above 800 kW in the entire state of Tamil Nadu.
- In case of failure to comply with these directions, appropriate action may be initiated under the provisions of Environment (Protection) Act, 1986 and Air (Prevention and Control of Pollution) Act, 1981.
Please note that while this notification is dated 30th July 2025, it has been recently made available in the public domain
The circular is linked below for your reference.
Source: Tamil Nadu Pollution Control Board
