*Delhi-NCR to be strengthened with expansion of Continuous Ambient Air Quality Monitoring Stations (CAAQMS)* The air quality monitoring framework in Delhi-NCR is being significantly strengthened through systematic augmentation of the Continuous Ambient Air Quality Monitoring Stations (CAAQMS) network, in order to ensure spatial coverage, improved data reliability and robust scientific assessment of air pollution across the region. The initiative is aimed at enhancing real-time air quality surveillance and supporting evidence-based policy interventions for effective air pollution abatement in Delhi-NCR. As part of the ongoing strengthening of the air quality monitoring network, the Commission for Air Quality Management in NCR and Adjoining Areas (CAQM) has been reviewing the status of augmentation of 27 new CAAQMS across Delhi-NCR [06 in Delhi, 07 in Haryana (NCR), 04 in Rajasthan (NCR) and 10 in Uttar Pradesh (NCR)], over and above the existing network of 84 monitoring stations (40 in Delhi, 22 in Haryana-NCR, 04 in Rajasthan-NCR and 18 in Uttar Pradesh-NCR) operated by concerned agencies in the region. Out of the 27 new CAAQMS across Delhi-NCR: 06 CAAQMS have been installed in Delhi; 07 new CAAQMS in Haryana (NCR), 04 in Rajasthan (NCR) and 10 in Uttar Pradesh (NCR) are in the process of installation. In addition to the ongoing augmentation, the scientific criteria for future expansion of the air quality monitoring network in Delhi-NCR has also been deliberated in detail. It was emphasised that monitoring density must adequately reflect population distribution, land-use characteristics such as residential, traffic, industrial and background areas, urban contiguity and the rapid expansion of peri-urban/ suburban regions. The need for grid-based spatial coverage has been considered. Further, background and border stations are also required to better understand regional transport of pollutants and baseline air quality levels influencing Delhi-NCR. Accordingly, in addition to existing population-based norms for Delhi and contiguous cities of Ghaziabad, Noida, Greater Noida, Faridabad, Ghaziabad, Sonepat, norms have been framed for installation of air quality monitoring stations at approximately one station in each 25 sq. km. (5 km × 5 km grid), while other district headquarters and cities would have one station per 50 sq. km. area. Monitoring coverage in peri-urban and suburban areas has also been identified as critical for assessing inflow and outflow of pollution and understanding the impact of urban sprawl on regional air quality. Further, based on above-mentioned criteria, 46 additional stations including 14 in Delhi, 16 in Haryana (NCR), 01 in Rajasthan (NCR) and 15 in Uttar Pradesh (NCR) are required in Delhi-NCR to strengthen the air quality monitoring infrastructure and to ensure comprehensive and uniform air quality monitoring across Delhi-NCR. Taking into account the additional stations, total number of CAAQMS in Delhi-NCR would be 157 comprising of 60 stations in the Delhi, 45 in Haryana (NCR), 09 in Rajasthan (NCR) and 43 in Uttar Pradesh (NCR). The Commission reiterated that a robust and dense air quality monitoring network is vital for effective monitoring and mitigation of air pollution in the region. The ongoing and proposed augmentation of CAAQMS, will significantly enhance the ability to identify pollution sources, track trends and take necessary actions accordingly.