‘Crucial step for holistic data on pollution': Delhi set to add 6 new air quality monitoring stations

Indian Express

14-06-2025

Delhi is set to expand its air quality monitoring infrastructure with the installation of six new Continuous Ambient Air Quality Monitoring Stations (CAAQMS), targeting areas not typically associated with high pollution.
The expansion, led by the Delhi Pollution Control Committee (DPCC), is part of the ongoing efforts to develop a more granular understanding of pollution patterns across different urban environments, Environment Minister Manjinder Singh Sirsa told The Indian Express. He added that the government is aiming to have these stations operational by August, before winter sets in, when the city is hit by severe air pollution.
'It is a crucial step for holistic data on pollution in all areas,' he said. He emphasised the need to shift focus from only known pollution corridors to areas that are often assumed to be clean. 'It is a myth that so-called green areas are not polluted. Vehicular pollution is a cause of concern throughout the city. So, it is necessary that we get pollution data for such areas too, not just the usual hotspots,' he said.
The new stations will be installed at the campuses of Jawaharlal Nehru University (JNU) and Indira Gandhi National Open University (IGNOU) in South Delhi, the ISRO Earth Station near Malcha Mahal in Delhi's Ridge and Delhi Cantonment in New Delhi, the Commonwealth Sports Complex in Central Delhi, and the West Campus of Netaji Subhash University of Technology in Southwest Delhi.
At present, Delhi has 40 CAAQMS and 7 manual stations. Of these, 26 have been set up by the DPCC, while others by the India Meteorological Department (IMD), the Indian Institute of Tropical Meteorology (IITM), and the Central Pollution Control Board (CPCB).
The new stations would improve geographic coverage and bring under observation several areas that are not traditionally seen as pollution hotspots, said Sirsa.
The decision to move forward with these installations was taken in continuation of work initiated by the previous state government. Sirsa said the locations had already been identified earlier, and the current government is facilitating implementation by issuing formal work orders and commissioning the project.
The choice of sites follows national-level guidelines issued by the CPCB, which recommend how air monitoring stations should be located, as per officials.
According to these standards, the monitoring equipment should be placed in open areas with free airflow and away from trees, buildings, and direct pollution sources like chimneys or heavy traffic corridors. The sampler should typically be placed at 3 metres above ground level, and at least 25 metres away from direct sources like chimneys or roads.
Equipment must also be positioned away by at least 20 metres away from tree cover or obstructive structures, to avoid skewing data.
The Indian Express had reported last October regarding the Ministry of Environment, Forest and Climate Change (MoEFCC) plans to increase the number of air quality stations in Delhi-NCR, based on CPCB's population-based design criteria.
Under the framework, cities with 1–5 lakh of population require 4 stations, up to 10 lakh, 6 stations; up to 50 lakh, 8 stations, and beyond 50 lakh, at least 16 stations.
According to official documents, each station will be equipped with advanced instruments capable of monitoring key air pollutants such as particulate matter (PM10 and PM2.5), sulphur dioxide, nitrogen oxides, carbon monoxide, ozone, ammonia, and volatile organic compounds like benzene and toluene.
In addition, sensors will record weather data such as wind speed, temperature, and humidity. The data will be transmitted in real time to the central servers of Delhi's pollution control authority and the Central Pollution Control Board. A digital display board at each site will show the current air quality index and pollutant levels to the public.
The stations are designed to operate round-the-clock, with requirements in place to ensure that they are functional for at least 90% of the year. The third-party agency responsible for installation will also maintain the stations for the next ten years, ensuring regular calibration, data quality checks, and public accessibility. Monitoring staff and security personnel will be stationed at each location to oversee day-to-day operations and ensure uninterrupted data flow.