For Emil Vinayaraj, a resident of Jayamahal, regular commute has changed. “I have to take a different route now, avoiding Pottery Road where Namma Metro construction is happening. The situation in the area is far from livable right now for residents, as the dust and pollution is just too much,” he says. Emil’s house is close to three new metro stations along the Pink Line — Shivaji Nagar, Cantonment Station and Pottery Town — and residents of this entire area have been facing the brunt of the ongoing work.

Similarly, Sri Shanthini, who lives near the Electronic City metro construction says, “I have been avoiding going through the main road to avoid the unbearable pollution.” 

Mega construction projects create a lot of dust and pollution, but these issues can be mitigated with proper management of construction and demolition waste. But as Emil says, much of Metro construction in Bengaluru is happening in crowded areas, close to residential zones, without proper planning or management, which makes daily life very difficult for the people there.

In Bengaluru, Namma Metro Phase 2 construction began in 2016 and was expected to be open for operation in 2020, but has faced several delays. Now the deadline for the first phase of opening has been pushed to 2025, with two subsequent phases expected in 2026. These delays have created an additional cost burden of Rs 10,000 crore, but what the 8-year-long and ongoing construction has cost the city and its people is much more. Health and safety of commuters have been affected sharply. 

Metro construction in Bengaluru has been causing severe dust pollution and consequent drop in air quality levels across the city. If one takes a closer look, much of this is clearly attributable to the mismanagement of construction and demolition waste and the failure to follow appropriate mitigation measures.

Mismanagement of C&D waste

The Karnataka State Construction & Demolition (C&D) Waste Management Policy & Strategy 2024, prepared in compliance with the central Construction & Demolition Waste Management Rules 2016, categorises Bangalore Metro Rail Corporation Limited (BMRCL) as a service provider and has laid down some strategies to manage the waste and construction materials from the sites to ensure public convenience while construction is underway. 

The strategy includes, among other things, categorising waste into four groups:
(A) concrete
(B) soil
(C) steel, wood and plastics and
(D) bricks and mortar

Each of these categories need to be managed accordingly. The strategy also involves removal of C&D waste and clean up of the area every day, if possible or at timely intervals. No waste should pile up on the roads causing any hindrance.

The Environmental Impact Assessment report for Namma Metro construction also suggests some mitigation measures to control air pollution. Some of these measures include covering construction materials with tarpaulin, covering or spraying water regularly on temporary soil stockpiles, and barricading construction areas to reduce dust generation.

The service providers, BMRCL in this case, are responsible for managing the C&D waste. However common scenes near these metro construction sites suggest that none of these management strategies are followed properly. For example, the Blue Line (Airport to Silk Board) of the Namma Metro Phase 2 is being laid through KR Puram and Mahadevapura. Walking through this area, we saw construction material and waste dumped randomly by the roadside and on the platforms.

The Lowry Adventist College, Mahadevapura is one of the air-sensitive receptors as identified by the Environmental Impact Assessment Report for the Bengaluru Namma Metro Rail Project. Inhabited stretches such as commercial zones, schools, hostels, hospitals, office occupancies, places of public worship, etc. along any construction or infrastructure projects that will be affected by air pollution and noise generated due to Metro work are categorised as air-sensitive receptors. Here too, one finds construction waste piled up on the pedestrian platforms near the college, inconveniencing passers-by and exposing them to pollution. While this is just one example, this is a common sight in many places.

Local authorities from the Pollution Control Board are responsible for assessment of C&D waste management. An authority from the Karnataka State Pollution Control Board (KSPCB) said that notices have been issued to BMRCL, following which they are formulating a plan of action. The authority also added that while KSPCB issues directions for managing the waste, they do not have any strategies in particular for compliance checks.

Read more: Namma Metro has only worsened Bengaluru’s traffic congestion and air quality

Effects on air quality 

The drop in air quality levels caused due to such mismanagement is a major concern. The Center for Study of Science, Technology and Policy (CSTEP) did a source apportionment study in 2022, to identify polluting sources for Bengaluru. 

Studies in the Export Promotion Industrial Park (ITPL) area suggest that soil and construction dust was observed in all seasons. The contribution of construction dust to PM2.5 concentrations in air ranged between 0.1% in summer and 0.3% in winter, while for PM10, it ranged between 6% in summer and 12% in monsoon. According to the study, this could be attributed chiefly to the construction of a metro line during the time of the sampling.

Special monitoring at sites

According to CAAQM reports from November 2024, the maximum levels of particulate matter  recorded — especially PM10 — are comparatively higher in the CAAQM (continuous ambient air quality monitoring) stations closer to the metro construction sites. While this cannot definitively be attributed only to metro construction, what is important to assess is whether the BMRCL is monitoring air quality regularly near metro construction sites in particular. Even if they are, no report has been released after the 2020 EIA report.

We did not receive any response from BMRCL when we enquired about their efforts in that direction and towards addressing pollution-related concerns.

The EIA report suggests regular local monitoring of the air quality in sensitive locations around the metro construction sites. The 13 Continuous Ambient Air Quality Monitoring (CAAQM) stations developed by the Karnataka Pollution Control Board are not sufficient for capturing the impact on pollution in these areas.

“These monitors (CAAQMS) are not necessarily near the metro construction sites, so the specificity of that particular polluter can not be captured. Also, they are limited and costly. But there are enough low-cost monitoring networks available that give you a good sense of what is happening”, says Ankit Bhargava, co-founder of Sensing Local Foundation. Efforts should also be made to talk to the locals to understand the nature of the pollution.

Ankit adds, “We have no redressal system, the practices are completely non-transparent. With the visible dust on the road, we can see that the protocol and suggested measures are not being followed properly. There needs to be accountability and transparency around what is supposed to be done, what is being done and what needs to be done by the BMRCL to control pollution.”

Read more: Bengaluru’s climate challenge: How the city can reduce its carbon footprint

Dust mitigation

“Due to pollution, nasal problems have become common. While there is some cleaning up taking place in a few areas, it is not carried out uniformly or regularly across sites. If it was done properly in all the sites, the condition would be better,” says Abinanthan, a resident of Marathahalli and an IT employee.

“The immediate step should be to clear the road dust around the sites regularly, because that is what is causing the most amount of harm from an air pollution perspective,” suggests Ankit. To that end, the following mitigation measures could, to some extent at least, reduce the impact on health and daily life:

• Metro construction sites and the roads nearby should be cleaned on a regular basis,  and all construction material kept covered.
• Ambient air quality needs to be monitored regularly and the data should be made transparent to include the public in the discourse.
• Measures taken — when, where and what — should be transparently published for the public to be aware of and raise alarm wherever required.
• A redressal mechanism should be immediately put in place to seamlessly address the grievances of the citizens.

Also read:

• Air pollution in the south: Here’s what Bengaluru, Hyderabad and other cities are inhaling
• Chennai Metro Rail work: Must commuters risk life and limb for ‘a better tomorrow’?