The Ministry of Environment, Forest and Climate Change (MoEFCC) has issued the Environment (Protection) Fourth Amendment Rules,2025 effective from 11th July 2025, amending the Environment (Protection) Rules,1986.

This amendment revises the applicability and timelines for compliance with Sulphur dioxide (SO₂) emission standards and other environmental parameters for coal and lignite-based Thermal Power Plants (TPPs) across India, based on stakeholder consultations and recommendations from Central Pollution Control Board (CPCB).

Key Highlights of the Amendment:

1. Categorization of Thermal Power Plants (TPPs)

TPPs are categorized based on their location:

• Category A: Within a 10 km radius of the National Capital Region or cities with population >1 million (as per 2011 Census).
• Category B: Within 10 km of Critically Polluted Areas or Non-attainment Cities (CPCB-defined).
• Category C: Other than those included in category A and B.

2. Compliance Timelines for Parameters Other than SO₂

• For non-retiring units, the compliance timelines for emission standards are set as follows: Category A plants must comply by 31st December 2022 with the same date as the retirement exemption deadline; Category B plants by 31st December 2023 with retirement exemption until 31st December 2025; and Category C plants by 31st December 2024, also with a retirement exemption deadline of 31st December 2025.
• TPPs retiring before exemption deadlines must submit undertakings to CPCB & Central Electricity Authority (CEA).
• Non-compliant plants operating beyond their declared retirement date will be subject to an Environmental Compensation (EC) of ₹0.40 per unit of electricity generated.

3. Applicability of SO₂ Emission Standards

TPPs declared to retire before 31st December 2030 are exempt from SO₂ compliance, subject to submission of an undertaking to CPCB and CEA; penalty applies if continued after the deadline.

1. Category A:
1. Existing & under-commissioning plants must comply by 31st December 2027.
2. Other category A plants to be commissioned after 31st December 2027 will operate only after ensuring compliance of these standards;
2. Category B:

The applicability of SO₂ standards will be determined by MoEFCC on a case-by-case basis, considering recommendations from the Expert Appraisal Committee (EAC) under the EIA Notification, 2006, through the following process:

1. Plants with Existing Environmental Clearance (EC):
• May apply for a review of SO₂ standards applicability via the PARIVESH portal within six months of this notification.
• If SO₂ standards are applicable must comply by 31st December 2028.
• If SO₂ standards are not applicable the plant must comply with stack height norms under Notification GSR 742(E) dated 30th August 1990, by 31st December 2028.
2. Upcoming Plants without EC:
• Applicability of SO₂ standards and compliance timelines will be specified in the EC granted, following the EIA Notification, 2006 process.
• If SO₂ standards are not applied, these plants must meet stack height norms as per GSR 742(E), dated 30th August 1990.
3. For plants not applying for review within the given timeframe, SO₂ standards will automatically apply from 31st December 2028.
3. Category C:
• SO₂ standards are not applicable.
• Must ensure compliance with stack height norms under GSR 742(E) by 31st December 2029.

4. Provision for Extension of SO₂ Compliance Timelines

The Central Government (MoEFCC) may extend SO₂ Emission standards compliance timelines for thermal power plants on CPCB’s recommendation.

5. Environmental Compensation for Non-Compliance

Non-retiring and non-compliant thermal power plants operating beyond the specified timelines will be subject to Environmental Compensation (EC) as follows: