New Delhi: With Delhi consistently ranking among the world’s most polluted cities over the last three decades, the nation’s capital has been the focus of attention for government bodies, judiciary and agencies looking to fix air quality. This attention dates back to the 1990s when the air began turning toxic, leaving a visible haze hanging over the city each winter.
Bodies such as the Central Pollution Control Board, the state pollution control boards and the Supreme Court-appointed Environment Pollution (Prevention and Control) Authority were all formed by the year 1998, with the Supreme Court initiating a major change across the capital by the year 2002 as it asked for all public transport to shift to compressed natural gas (CNG), a move that has reaped benefits for Delhi, but has failed to pick up across neighbouring NCR towns.
Worldwide though, examples have shown taking an “airshed” approach — which considers a large geographical area instead of simply working on individual cities and towns — is the way to collectively solve air pollution, a problem Delhi and its neighbouring states have been unable to address thus far.
The Commission for Air Quality Management (CAQM) for NCR and its adjoining areas has recently looked to address this issue, imposing similar restrictions across NCR as those imposed by the Delhi government. On November 14, the Delhi government stopped construction activities, shut down schools and colleges and made government offices work from home. Two days later, the Commission issued a similar order, banning all of these activities, but across NCR.
The airshed approach
Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE), says that while a large number of judgements including from the Supreme Court have asked for NCR to be seen as an airshed region, being the national capital, Delhi has always been thrust into the limelight and has therefore seen faster changes. “The idea has always been to consider NCR as a whole and to bring about a change in the entire region at the same time, but Delhi being the capital has always been under the scanner. At this stage, you now need a two-tier approach. A top-tier approach from the Centre and a bottom-up preparedness from the state governments. We need both to function in harmony to see any form of visible change,” says Roychowdhury, stating coordination between states has been an important factor, but states also needed to act individually.
Roychowdhury suggests measures which could be implemented now includes switching thermal power plants to cleaner technology, adopting cleaner fuels across industries in NCR and using new CNG or electric based buses.
“Directions issued by a common central body such as EPCA, or the Commission now, are not enough. The states need to set clear timelines for themselves and act on their individual sources of pollution. Once this is done, the region starts seeing improvements on its own. Certain measures will require the same timelines and efforts across each NCR state and city and there the Commission has to ensure implementation,” she added.
PNG and electric vehicles the way forward?
Delhi currently has opted for a dual-approach to phase out dirtier, more polluting fuels for both vehicles and industries. While industries that are yet to switch to piped natural gas (PNG) are being shut down by the Delhi Pollution Control Committee (DPCC), the registration certificates of 15-year-old petrol and a 10-year-old diesel vehicle are not being renewed and instead, there are subsidies for electric vehicles.
Amit Bhatt, Director, Integrated Urban Transport at WRI says the ship for NCR to adopt CNG has now sailed, with the focus now required on switching public transport to electric vehicles. “Delhi did extremely well and benefitted after CNG was adopted. While the switch happened for the capital, we are yet to see a comprehensive CNG network and implementation across NCR towns and that has meant pollution from those sources has remained in the air,” said Bhatt.
He feels while CNG is cost-effective, Delhi’s electric-vehicle policy is comprehensive and other states can adopt a similar mechanism. “All states need to be on the same wavelength and work in tandem. Only then can the vehicle sector see a reduction in the overall pollution load,” said Bhatt.
On its part, the Delhi government has been suggesting to the Centre and its neighbours that they adopt CNG for their public transport fleets. In October, Delhi environment minister Gopal Rai emphasized this point in a meeting which included the chairman of the Commission on Air Quality Management in NCR, M.M Kutty and Union environment minister Bhupender Yadav.
Hot mix plants, stone-crushers and brick-kilns all thrive outside Delhi
Sunil Dahiya, an analyst at the Centre for Research on Energy and Clean Air (CREA) said while a number of industries had been shifted out of Delhi, brick-kilns, hot-mix plants and stone crushers that abound in NCR towns were still a factor.
As part of the Graded Response Action Plan (GRAP), these units need to be shut down across NCR when air quality hits severe – crossing a PM 2.5 threshold of 250 micrograms per cubic metre and a PM 10 concentration of 430 micrograms per cubic metre. “Over the last couple of years, a lot of brick-kilns were made to switch to the cleaner zig-zag technology, but a lot of them are still to do so. These units get more attention each winter during GRAP and are shut down, but through the year, they remain a problem,” he says.
Brick-kilns release carbon monoxide and sulphur dioxide during the brick-firing process, in addition to both PM 2.5 and PM 10. Stone crushers release large amounts of PM 10 and dust, while oxides of nitrogen, oxides of sulphur and CO are again released through hot-mix plants.
Thermal power plants – an annual source of high pollution to Delhi
Delhi may have shut down its two coal-based thermal power plants in 2015 and 2018, but the city still has at least 12 major power plants within a 300-km radius. While these power plants were supposed to switch to the cleaner flue-gas desulfurization (FGD) technology as per norms issued in 2015 by the Ministry of Environment, Dahiya says only 2 out of 12 power plants have so far initiated the move.
To curb the pollution that emanates from these coal-based plants, five of them have been temporarily shut down in the region since November 17. This is the first time a regulating body has shut down thermal power plants to control pollution.
“The Dadri power plant and the Jhajjar plant have installed FGD technology to control sulphur dioxide emissions, but apart from them, none of the remaining plants is meeting the standards. The approach adopted by the CAQM is good in the sense that those not meeting the 2015 standards, should be shut down,” Dahiya said.
A study released earlier this year, carried out by IIT Kanpur, says that the contribution to pollution of power plants remains high even during summers, accounting for around 16.2% of Delhi’s total PM 2.5 load, second, only behind dust. Sachchida N. Tripathi, HoD – Civil Engineering, IIT Kanpur, who carried out the study, said data from real-time source apportionment done in June and July of 2019, found high sulfate levels in Delhi’s air, which are generally released when oxides of sulphur react with heat. “Based on the direction they were coming from, we knew it was from power plants and no other source,” said Tripathi.
The way ahead for the region
Karthik Ganesan, Fellow and Director of Research and Coordination at the Council on Energy, Environment and Water (CEEW), says addressing as many sources of pollution within NCR will be key. “As we can see from the impact of episodic farm fires, impacts of distant sources are also felt in Delhi. Attention must be paid to the uniform implementation of nationally accepted emissions standards and mitigation measures in all sectors, without special focus on Delhi. While Delhi’s efforts to introduce CNG and PNG are commendable, the scalability of these interventions is a challenge in the wider geography. Implementing emissions norms through continuous monitoring and surveillance is likely to be far more impactful than looking to replicate solutions that Delhi has implemented,” said Ganesan.
Roychowdhury meanwhile stressed on better coordination between states. “We need the states to work together to address common issues as air pollution will travel from one NCR city to another. As long as each state government is committed, we cannot bring about a substantial difference,” she added.