Observing that air quality in the national capital was ‘severe’ for most of the month, the National Green Tribunal (NGT) has directed implementation of a graded response action plan, to combat different levels of air pollution. The apex environment watchdog also said there was no uniformity and ‘unanimity’ in the action plans of the Central Pollution Control Board (CPCB) and the Supreme Court-appointed Environment Pollution (Prevention and Control) Authority (EPCA).
The air-quality categorisation needs ‘clarity and certainty’, it said in its order. “The statistics clearly show that the ambient air quality of NCT of Delhi is polluted all the time, and for most of the period of the month, it is severe and above. This is the quality of air that we are providing to the people living in NCR Delhi and NCT of Delhi. It is a clear violation of their fundamental right,” said a bench headed by former chairperson Swatanter Kumar.
Pollution categories framed by the NGT
Category I (Average): This action plan would come in force when PM10 is more than 100 micrograms per cubic metre but less than 300 and PM2.5 is more than 60 but below 180.
Category II (Severe) will be in action when PM10 is more than 300 micrograms per cubic metre but less than 700 micrograms per cubic metre and PM2.5 is more than 180 but below 400 micrograms per cubic metre.
Category III (Critical) would be implemented when PM10 is more than 700 micrograms per cubic metre but below 1,000 micrograms per cubic metre and PM2.5 is more than 400 micrograms per cubic metre but less than 600 micrograms per cubic metre.
Category IV (Environmental Emergency) would be termed when PM10 is above 1,000 micrograms per cubic metre and PM2.5 is above 600 micrograms per cubic metre.
Pollution categories framed by the CPCB
The CPCB has formulated six categories, which refer to different levels of pollution – good, satisfactory, moderately polluted, poor, very poor, severe and above severe.
EPCA’s action plan
EPCA’s action plan, termed Graded Response Action Plan (GRAP), has formulated five categories. These are severe plus or emergency, severe, very poor, moderate to poor and moderate.
The NGT has sought the implementation of odd-even in its third category, but the current GRAP calls for the move at the emergency or highest levels. When air pollution reaches environmental emergency levels, thermal power plants in Delhi should be shut down and sprinkling of water from high-rise buildings should be done, the green tribunal said.
“There shall be complete prohibition on use of diesel generator sets. The trucks and heavy vehicles carrying material including trailers shall be prohibited from entering NCT of Delhi. Only heavy vehicles carrying essential goods like medicine, food, etc., would be permitted, while all other heavy vehicles will not be permitted to enter NCT of Delhi, for the duration of environmental emergency,” the NGT said. Terming as ‘critical’ levels of pollution in the third category, the NGT said immediate steps, including a ban on construction and introduction of the odd-even scheme, should be implemented by the authorities.
EPCA says NGT’s plan will dilute GRAP
The EPCA, however, said the latest measures announced by the NGT to clean the city’s toxic air may ‘dilute’ the Centre-notified GRAP and create ‘confusion’ among the implementing agencies. Sunita Narain, a member of the EPCA, said the GRAP, which it is authorised to enforce, was much more ‘stringent’.
According to the categorisation of the NGT’s action plan, measures such as ban on construction activities, diesel generator sets, thermal power plants and closure of schools, will kick in when levels of PM2.5 and PM10 cross 600 and 1,000 micrograms per cubic metre, respectively. The green tribunal defines the aforementioned category as ’emergency’. It says the odd-even road rationing scheme is to be rolled out, when ultrafine particulates PM2.5 and PM10 range between 400-600 and 700-1,000 micrograms per cubic metre, a level defined as ‘critical’ by it.
In contrast, under the GRAP, which was notified by the centre on January 12, 2017, a pollution emergency is declared when PM2.5 crosses 300 micrograms per cubic metre and PM10 breaches 500 micrograms per cubic metre, the level when steps such as odd-even and construction ban are to be implemented.
Apart from the Badarpur plant, the EPCA does not recommend closure of thermal power plants in the region. However, it suggests that steps be taken to ensure the gradual shift to gas-based power generation from coal-based plants.
“They (NGT) have diluted it. The GRAP is much more stringent. Moreover, the GRAP is notified, it is law. No one can afford to not implement it. This was unnecessary and will only lead to more confusion,” Narain said. Chances of 24-hour average of pollutants in Delhi crossing the emergency threshold fixed by the NGT are not very high at this point, which also means that tough actions will remain largely on abeyance, the EPCA said.
Anumita Roychowdhury of the Centre for Science and Environment (CSE), which works closely with the EPCA, also observed that the NGT plan was unclear. “If you are changing the basic architecture, it is going to be confusing for the implementing agencies,” she said.