Executive Summary:
The Ministry of Environment, Forest and Climate Change (MoEFCC) addressed concerns regarding the mandatory installation of Flue Gas Desulphurisation (FGD) systems in coal-fired thermal power plants (TPPs). A notification (G.S.R. 465 E dated 11.07.2025) was issued regarding the applicability of SO2 emission standards based on plant categories, with varying compliance timelines. Plants were categorized based on location and other factors, with considerations for techno-economic feasibility, air quality, and potential impact on electricity prices.
Key Points / Main Content:
* **Emission Standards Review:**
* The SO2 emission standards notified on 07.12.2015 were reviewed due to concerns regarding technology availability, economic feasibility, COVID-19 impacts, and potential consumer burden.
* Studies by CSIR-NEERI, IIT Delhi, and NIAS, along with CPCB modelling, were considered to evaluate the need for universal applicability.
* **Category-Based Applicability:**
* Category A: Plants within 10 km of NCR or cities with a million-plus population must comply by 31.12.2027.
* Category B: Plants within 10 km of non-attainment cities or critically polluted areas; applicability to be decided case-by-case by the Central Government based on Expert Appraisal Committee recommendations, with a compliance deadline of 31.12.2028. Plants considered for non-applicability must meet stack height requirements as per Notification no. G.S.R. 742 E dated 30.08.1990.
* Category C: Other plants not included in Categories A and B are not applicable for FGD, subject to meeting stack height requirements as per Notification no. G.S.R. 742 E dated 30.08.1990 and compliance by 31.12.2029.
* **Categorization and Rationale:**
* Out of 600 TPP units, 66 are in Category A, 72 in Category B, and 462 in Category C.
* Categorization was done by a CPCB task force (MoEFCC, Ministry of Power, CPCB, and CEA representatives) per Notification G.S.R. 243E dated 31.03.2021.
* The category-wise applicability is based on scientific studies and analysis of ambient SO2 concentrations.
* The decision considers environmental sustainability, techno-economic feasibility, resource conservation (water, power, limestone), and potential electricity price increases.
* **Enforcement and Alternatives:**
* TPPs must comply with emission standards within the prescribed time limits; non-compliance will result in environmental compensation.
* TPPs not required to implement FGD must comply with stack height criteria as per Notification GSR 742 E dated 30.08.1990.
Impact Analysis:
Thermal Power Plants (TPPs):
* Impact: TPPs face differentiated requirements for FGD installation based on their category, affecting investment decisions and operational costs. They may face penalties for non-compliance or be required to meet stack height requirements.
* Action Required: Determine their category, plan for FGD installation or alternative measures (meeting stack height norms), and ensure compliance within specified timelines.
Consumers:
* Impact: Electricity prices may be affected by the costs associated with FGD installation or alternative pollution control measures.
* Action Required: Be aware of potential price fluctuations due to environmental compliance costs for TPPs.
Technology Providers:
* Impact: The demand for FGD technology may vary based on the number of plants requiring installation, influencing business opportunities.
* Action Required: Monitor the categorization of TPPs to understand the potential market for FGD systems.
Environment and Public Health:
* Impact: The revised emission standards aim to balance environmental protection with economic feasibility, potentially affecting air quality and public health in different regions.
* Action Required: Monitor air quality in areas surrounding TPPs to assess the effectiveness of the revised standards.
Key Entities Referenced
Ministry of Environment, Forest and Climate Change: The Indian government ministry responsible for environmental protection and climate change policies. Also referred to as MoEFCC.
Flue Gas Desulphurisation (FGD): A technology used to remove sulfur dioxide (SO2) from exhaust flue gases of fossil-fuel power plants.
Central Pollution Control Board (CPCB): A statutory organisation under the Ministry of Environment, Forest and Climate Change responsible for pollution control.
National Capital Region (NCR): The metropolitan area which encompasses Delhi and its surrounding areas in adjacent states.
Central Electricity Authority (CEA): A statutory organization, originally established under the Electricity (Supply) Act, 1948, and subsequently continued under the Electricity Act, 2003.
Indian Institute of Technology (IIT Delhi): An Institute of National Importance, which conducted study to survey ambient atmospheric SO2 concentrations in different category of cities based on their vicinity to thermal power plants TPPs
Indian Institute of Tropical Meteorology (IITM, Pune): An autonomous research institute under the Ministry of Earth Sciences, which conducted a simulation modelling of emission from source of Thermal Power Plant for different scenariosmatrix.
Notification dated 07.12.2015: Notification by the Ministry of Environment, Forest and Climate Change (MoEFCC) that notified emission standards for coal-lignite fired Thermal Power Plants (TPPs).
GOVERNMENT OF INDIA
MINISTRY OF ENVIRONMENT, FOREST AND CLIMATE CHANGE
LOK SABHA
UNSTARRED QUESTION NO. 3469
TO BE ANSWERED ON 11.08.2025
Installation of FGD Systems
3469. SHRI MANISH JAISWAL:
SHRI DHAIRYASHEEL SAMBHAJIRAO MANE:
SHRI SUDHEER GUPTA:
SHRI MANISH TEWARI:
SHRI CHAVAN RAVINDRA VASANTRAO:
SHRI MANICKAM TAGORE B:
Will the Minister of ENVIRONMENT, FOREST AND CLIMATE CHANGE be pleased to
state:
(a) whether the Government has recently exempted a substantial number of coal-fired thermal
power plants from the mandatory installation of Flue Gas Desulphurisation (FGD) systems;
(b) if so, the details thereof along with the specific criteria and rationale used to determine these
exemptions, including the reasons for adopting location-based emission norms instead of
uniform national standards;
(c) the details of exempted units along with the criteria and scientific basis for classifying units
into Categories A, B, and C for the purpose of FGD requirements;
(d) whether any health impact assessments or regional air quality modelling studies were
conducted prior to issuing the exemption, particularly in areas downwind of major coal
clusters, if so, the details thereof;
(e) the details of the alternative pollution control technologies, emission limits, or monitoring
protocols will be mandated in lieu of FGD installation to mitigate the environmental and
public health impacts from such exempted plants;
(f) Government plan to strike a balance between reducing air pollution and supporting the
economic viability of thermal power plants, especially those exempted from FGD
compliance; and
(g) the status of implementation of the recommendations made by the Expert Committee on the
issue of emission control in the thermal power plants?
ANSWER
MINISTER OF STATE IN THE MINISTRY OF ENVIRONMENT, FOREST AND CLIMATE
CHANGE
(SHRI KIRTI VARDHAN SINGH)
(a) to (g):
The Ministry of Environment, Forest and Climate Change (MoEFCC) notified emission
standards for coal/lignite-fired Thermal Power Plants (TPPs) vide Notification dated 07.12.2015.
The SO emission standards prescribed vide Notification dated 07.12.2015 have been reviewed
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by the Central Government taking into consideration the various representations receivedregarding exemption or relaxation in timelines of these emission standards due to limited
availability of technology providers, its techno-economic feasibility, negative impact of COVID-
19 pandemic on supply chain, price escalation due to high demand and low supplies, low
Sulphur dioxide concentration in ambient air and heavy burden on consumer due to increase in
electricity prices etc.
Besides, several studies conducted by research institutions such as CSIR-National Environmental
Engineering Research Institute (CSIR-NEERI) [report titled as “Analysis of Historical Ambient
Air Quality Data along with Emission from coal-based Thermal Power Plants for Developing a
Decision Support System”], Indian Institute of Technology (IIT) Delhi [report titled as “Study to
survey ambient atmospheric SO concentrations in different category of cities based on their
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vicinity to thermal power plants (TPPs)”],National Institute of Advanced Studies (NIAS) [report
titled as"Economic, Environmental, and Climate Impacts of Flue Gas Desulphurisation (FGD) in
Thermal Power Plants in India”], regarding effectiveness and rationale behind these standards
and its role in overall ambient air pollution of the region, were also considered to evaluate the
need of universal applicability and enforcement of these standards. Apart from these studies,
Central Pollution Control Board (CPCB) had also conducted a simulation modelling of emission
from source of Thermal Power Plant for different scenarios/matrix through Indian Institute of
Tropical Meteorology (IITM), Pune.
After detailed review of the matter, the Ministry has issued Notification vide G.S.R. 465 (E)
dated 11.07.2025 regarding the applicability of SO emission standards notified vide Notification
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dated 07.12.2015. Accordingly, the applicability and timelines for compliance of SO emission
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standards by TPPs are as follows:
Category Applicability of SO emission standards Time limit for
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compliance
Category A (Plants within 10 Mandatory 31.12.2027
km radius of NCR or cities
having million plus population)
Category B (Plants within 10 To be decided on a case to case basis by 31.12.2028
km radius of non-attainment the Central Government based upon the
cities or critically polluted areas) recommendations of the Expert Appraisal
Committee (Thermal Projects).
In case any TPP is considered for non-
applicability of SO emission standards,
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such TPP shall ensure meeting stack
height as per Notification no. G.S.R. 742
(E) dated30.08.1990.
Category C (Other than those Not applicable subject to condition of 31.12.2029
included in Category A and B) meeting stack height as per Notification
no. G.S.R. 742 (E) dated 30.08.1990.
Out of 600 TPP units commissioned up to 30.11.2021 as per information available from Central
Electricity Authority (CEA), 66 units are under Category ‘A’, 72 units are under Category ‘B’,
and 462 units are under Category ‘C’. The TPP units are categorized by the task force constituted
by CPCB comprising of representatives from MoEFCC, Ministry of Power, CPCB and CEA, in
compliance with the MoEFCC Notification G.S.R. 243(E) dated 31.03.2021.The category-wise applicability of SO emission standards in TPPs has been decided based on
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detailed scientific studies and analysis of ambient SO concentrations across the country,
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including areas near TPPs. The decision taken by the Central Government while issuing
Notification dated 11.07.2025 is based on scientific approach, environmental sustainability and
environmental benefits/loss in achieving SO emission norms as well as techno-economic
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feasibility of implementing such control measures across all coal/lignite-based TPPs. This
approach applies the precautionary principle for controlling and abating air pollution in densely
populated and other air pollution-sensitive areas, while also considering to safeguard consumers
from the heavy burden due to potential increases in electricity prices. This approach further
demonstrates resource conservation by avoiding additional consumption of water, auxiliary
power, and limestone; it also considers the increase in carbon footprint/CO emissions resulting
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from the operation of deployed control measures, as well as the mining and transportation of
limestone required for these measures.
TPPs are required to comply with the emission standards notified by MoEF&CC within the
prescribed time limits, failing which environmental compensation shall be imposed on the non-
compliant TPP units for operation beyond the prescribed time limit at prescribed rates. In all
such cases where SO emission standards are not being made applicable, TPPs shall ensure
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compliance of stack height criteria notified vide Notification number GSR 742 (E) dated the
30.08.1990 governing SO emissions from TPPs to aid proper dispersion of pollutants and
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mitigate environmental impacts.
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