Question 1

All thermal power plants across India must eventually install pollution control systems to reduce SO2 emissions.

Accepted Answer

Under the 2025 amendment, Category C plants (which constitute over 75 percent of India's thermal capacity) are completely exempted from SO2 standards and do not need to install FGDs if they build sufficiently high stacks.

Question 2

Aging thermal power plants are automatically exempted from pollution norms.

Accepted Answer

There is no automatic exemption. Retiring plants must formally submit a written undertaking to the CPCB and CEA committing to retire by December 31, 2030. Operating beyond this date attracts the highest penalty bracket of Rs 0.40 per unit.

Question 3

Consider the following statements regarding the Environment (Protection) Fourth Amendment Rules, 2025: 1. Category C thermal power plants are completely exempted from Sulphur Dioxide emission standards provided they meet specific stack height criteria. 2. Thermal power plants located within a 10 km radius of Critically Polluted Areas fall under Category A. 3. Flue Gas Desulfurization (FGD) systems are primarily installed in thermal power plants to control the emission of nitrogen oxides (NOx). How many of the statements given above are correct?

Accepted Answer

(a) Only one — Statement 1 is correct as per the July 2025 MoEFCC notification. Statement 2 is incorrect; plants within 10 km of Critically Polluted Areas or Non-attainment cities are classified as Category B, whereas Category A covers the National Capital Region and million-plus population cities. Statement 3 is incorrect; FGD systems are specifically designed to scrub Sulphur Dioxide (SO2), whereas Selective Catalytic Reduction (SCR) is used for nitrogen oxides.

Question 4

Match List I (Thermal Power Plant Category/Status under 2025 rules) with List II (Compliance Provision): 
List I: 
A. Category A plants 
B. Category B plants 
C. Category C plants 
D. Retiring plants 
List II: 
1. Can apply on PARIVESH portal for review of SO2 applicability 
2. Must comply with SO2 norms by December 31, 2027 
3. Exempted from SO2 norms if an undertaking is given to retire by December 2030 
4. Completely exempted from SO2 norms subject to 1990 stack height criteria

Accepted Answer

(a) A-2, B-1, C-4, D-3 — Category A plants strictly have until Dec 31, 2027 to comply (A-2). Category B plants can seek a case-by-case review via the PARIVESH portal (B-1). Category C plants are exempt if they meet stack height criteria (C-4). Retiring plants are exempt only if they declare retirement by 2030 (D-3).

Question 5

Assertion (A): The Ministry of Environment, Forest and Climate Change exempted Category C thermal power plants from SO2 emission standards in the 2025 rules. 
Reason (R): Category C plants account for a very small fraction of India's total thermal power capacity, making their aggregate SO2 emissions negligible.

Accepted Answer

(c) A is true but R is false — Assertion (A) is true as the Environment (Protection) Fourth Amendment Rules, 2025 did exempt Category C plants subject to stack height norms. Reason (R) is false because Category C plants actually represent the vast majority (more than 75 percent) of India's thermal power capacity. The exemption was granted due to cost constraints, supply chain issues for FGDs, and techno-economic feasibility, not because their capacity or emissions are negligible.

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