Delhi's Air Quality Monitoring Stations Largely Compliant with National Guidelines
New Delhi: A significant report from the Public Accounts Committee (PAC) on pollution, presented in the Delhi Assembly this week, has disclosed that the vast majority of continuous ambient air quality monitoring stations (CAAQMS) in the national capital are operating in accordance with Central Pollution Control Board (CPCB) location guidelines. The comprehensive assessment, which scrutinizes the city's efforts to combat vehicular air pollution, highlights that only three stations—Anand Vihar, RK Puram, and Jahangirpuri—do not fully meet the established criteria.
Response to CAG Audit Findings on Monitoring Infrastructure
This PAC report was specifically prepared in response to a performance audit conducted by the Comptroller and Auditor General (CAG) titled "Prevention and Mitigation of Vehicular Air Pollution in Delhi for the year ended March 31, 2021." The CAG audit had raised concerns about 13 CAAQMS stations, citing potential issues related to their proximity to trees, major roadways, obstacles, high-rise buildings, and unpaved roads. The audit warned that incorrect station placement could lead to inaccurate observations and the generation of unreliable air quality data, undermining pollution control efforts.
In its detailed findings, the PAC report clarified that a joint team from the Delhi Pollution Control Committee (DPCC) and CPCB was formed in 2022 to evaluate and identify CAAQMS locations strictly according to CPCB guidelines. The committee observed that all the CAAQMS are meeting the siting criteria as per CPCB guidelines, except Anand Vihar, RK Puram and Jahangirpuri, the report stated. It further explained that the Commission for Air Quality Management in NCR and Adjoining Areas (CAQM) decided against relocating these three stations due to critical factors such as dense population concentrations and historically high pollution levels. These locations are deemed essential for maintaining data continuity and capturing outlier readings that reflect extreme pollution events.
Additionally, the report noted that CPCB conducted monitoring at an alternate site near Anand Vihar and found no significant variation in air quality parameters, supporting the decision to retain the existing station locations.
Addressing Specific Pollutants and Monitoring Gaps
The CAG audit had also highlighted specific monitoring deficiencies, including the DPCC's failure to measure lead levels in Delhi's ambient air and benzene concentrations at fuel stations. In response, the PAC report cited DPCC's clarification that CAAQMS stations are not equipped to monitor lead directly. However, lead concentration was separately monitored at five distinct locations between April and September 2022, with results indicating no significant lead content detected in the ambient air at any of these sites.
Regarding benzene emissions, the PAC report observed that vapour recovery systems (VRS) have been installed at fueling stations by Bharat Petroleum Corporation Limited (BPCL) in full compliance with CPCB guidelines. These systems are designed to capture harmful vapors during fuel dispensing, thereby reducing benzene release into the atmosphere.
Irregularities in Pollution Under Control Certificates and Transport Initiatives
The PAC report further addressed irregularities in Pollution Under Control (PUC) certificate checks flagged by the CAG audit. It detailed the transport department's explanation that discrepancies arose due to data management issues with the Delhi e-Governance Society (DeGS). The problem was reportedly resolved after migrating the PUC application to National Informatics Centre (NIC) servers. During the audit period, the PUCC application used to be managed by DeGS. However, when DeGS was questioned for the discrepancies noted by the audit, it informed that these discrepancies have arisen from their own ongoing testing, as test data accumulated over 3-4 years had inadvertently merged with the main database, the report elaborated.
Between May 2023 and February 2025, nearly 1,850 inspections of PUC centers were conducted, leading to regulatory action against 491 centers found in violation of standards.
To enhance Delhi's public transportation infrastructure and improve last-mile connectivity, the PAC report noted the proposal to operate 100 electric Delhi Transport Corporation (DTC) buses under the Delhi Electric Vehicle Initiative (DEVI). The transport department has also executed a Memorandum of Understanding (MoU) with the Indian Institute of Technology (IIT) Delhi to undertake route rationalization for DEVI's 9-meter buses, with implementation currently in progress. DTC is also in the process of finalising a separate MoU with IIT-D for route rationalisation of DEVI 12-metre buses. The process is expected to be completed within the next six months, the report added, underscoring ongoing efforts to optimize public transport routes and reduce vehicular emissions.
This PAC report provides a thorough examination of Delhi's air quality monitoring framework and mitigation strategies, offering insights into the complexities of urban pollution management while addressing audit concerns with actionable responses and future-oriented transport initiatives.
