Delhi and nearby cities face heightened levels of pollution during the winter months. (Representational)
The Commission for Air Quality Management (CAQM) has revamped the Graded Response Action Plan - a set of anti-air pollution measures followed in Delhi and its vicinity according to the severity of the situation.
The review is part of a policy formulated by CAQM to abate the menace of air pollution in Delhi-NCR.
The Graded Response Action Plan (GRAP), notified by the Ministry of Environment and Forests in 2017, comes into force mid-October when air pollution levels in the region start worsening.
The GRAP for the National Capital Region (NCR) has now been classified under four different stages of adverse air quality in Delhi: Stage I - 'Poor' (AQI 201-300); Stage II - 'Very Poor' (AQI 301-400); Stage III - 'Severe' (AQI 401-450); and Stage IV - 'Severe' (AQI > 450).
The revised GRAP recommends a ban on coal and firewood, including in tandoors in hotels, restaurants, open eateries; and on diesel generator sets, except for emergent and essential services under Stage I.
If the situation turns "severe" (Stage III), authorities will have to enforce a ban on construction and demolition activities in NCR, except on essential projects (like railways, metros, airports, ISBTs, national security/defence-related projects of national importance) and non-polluting activities such as plumbing, carpentry, interior decoration and electrical works.
Brick kilns, hot mix plants and stone crushers not operating on clean fuels, and mining and associated activities in NCR will also be banned under Stage III.
"State governments in Delhi-NCR may impose restrictions on BS III petrol and BS IV diesel light motor vehicles (four wheelers) under Stage III," the policy document read.
The measures to be followed in the "emergency" situation or Stage IV include a ban on the entry of trucks into Delhi, and on the plying of Delhi-registered diesel-run medium goods vehicles and heavy goods vehicles (HGVs) in the national capital except those engaged in essential commodities.
The use of four-wheeler diesel light motor vehicles, except for BS-VI vehicles and vehicles engaged in essential services, will also be banned in Delhi and the bordering districts of NCR.
Stage IV will also entail a ban on industries running on dirty fuels and on C&D (construction and demolition) activities in linear public projects such as highways, roads, flyovers, over bridges, power transmission and pipelines.
"State governments can consider allowing 50 per cent staff to work from home in public, municipal and private offices, and additional emergency measures like closure of educational institutions and the plying of vehicles on odd-even basis etc," it said.
Actions under Stages II, III and IV will have to be taken at least three days in advance of the air quality index (AQI) reaching to the projected levels of that stage.
Earlier, authorities would wait until PM 2.5 or PM 10 concentration touched a particular threshold.
Under the 'severe plus' category, agencies waited for PM 2.5 and PM 10 concentrations to stay above 300 and 500 micrograms per cubic metre for 48 hours or more before implementing the measures mandated under GRAP.
"Proposed restrictions are to be progressive from a lower stage to higher stage, that is, restrictive actions undertaken as per previous stages shall be continued, in addition to the air pollution stage under which the restrictive actions are envisaged to be taken," the policy said.
The sub-committee on GRAP will meet frequently to plan for advance action and issue necessary orders for invoking various provisions of GRAP, based on the prevalent air quality and the AQI forecast to be provided by the India Meteorology Department (IMD) from time to time.
The policy was framed after the Supreme Court in December last year directed the CAQM to invite suggestions from the general public and experts in the field to find a permanent solution to the air pollution menace" in Delhi-NCR.
Experts had suggested proactive implementation of GRAP measures based on air quality forecasts, rather than retroactively implementing them once acceptable levels are breached.
The policy contains sector-wise recommendations for agencies and departments of central government, NCR states and Delhi to prevent, control and abate air pollution in the NCR due to industries, vehicles, construction and demolition, dust from roads and open areas, municipal solid waste burning, crop residue burning, among others.
It also deals with thermal power plants, clean fuel and electric mobility, public transportation, road traffic management, diesel generators, bursting of fire crackers and abating air pollution through greening and plantation.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)