GRAP 4 revoked in the city after AQI improves

As the air quality in Mumbai significantly improved over the weekend, the BMC on Monday revoked the Graded Response Action Plan (GRAP) 4 which was implemented in the city on November 27

MUMBAI: As the air quality in Mumbai significantly improved over the weekend, the BMC on Monday revoked the Graded Response Action Plan (GRAP) 4 which was implemented in the city on November 27. The overall AQI on that day was 167—however, several pockets in the city crossed the 300 mark or ‘Poor’ category, which prompted the enforcement.

Mumbai, India – 01, Dec 2025: A pedestrian walk past a mural, made to create awareness, on the eve of the World Pollution Day, in Mumbai, India, on Monday, Dec 01, 2025. (Photo by Bhushan Koyande/HT Photo)

According to the rules of the central government’s Commission for Air Quality Management, GRAP is to be implemented when the overall air quality in the city breaches the 200 mark for three consecutive days. Furthermore, if the air quality at individual stations crosses the 300 mark, work at all polluting sources such as ready-mix concrete plants, bakeries and construction sites has to be halted.

On November 28, the Air Quality Index (AQI) stood at 128; on the following day, it was 124, while on Sunday the stations registered an overall AQI of 103. On Monday, it was 114.

“The AQI started improving over the last week after restrictions were imposed. However, the weather conditions were also favourable for the improvement of air quality,” said an official. “At present the primary pollutants in the city are carbon monoxide and nitrogen dioxide emitted from vehicles. If the air quality deteriorates later in the season, we will implement GRAP again as and when required.”

Under GRAP 4, construction sites in the city were heavily monitored to ascertain that they were following the 28-point charter of guidelines. The BMC deployed 95 flying squads in the city to flag any irregularities and violations of these.

The civic body, in its Mumbai Air Pollution Action Plan (MAPAP), had identified dust displacement from construction sites as a primary contributing factor to the city’s plummeting air quality. Civic officials maintain that they have been sending notices to builders to ensure that sensors are installed at the earliest. “We are sending stop work notices to sites which are not following the rules. So far, we have issued show cause notices to 482 construction sites and stop-work notices to 264 projects across the wards,” said an official.