The demolition of the Supertech Twin Towers in Noida has triggered air pollution concerns, with experts warning that the air quality standards in the area need to be monitored for one-and-a-half months to ensure that pollution from the demolition does not coincide with the annual pollution factor.
On August 28, the two skyscrapers built by Supertech in Noida's Sector 93A were razed through a controlled explosion in which over 3,700 kg of explosives were placed into 9,400 holes in columns and shears. The total distance between the holes that were bored was close to 18 kilometres.
The demolition left behind more than 80,000 tonne of rubble, most of which will be used to fill the site and the rest would be recycled.
The current situation
Akash Vashishtha, an environmental lawyer, said, "The demolition of these towers has generated significant quantities of rubble, which resulted in the production of gigantic amounts of dust, as a result of which PM10 in the areas within its close vicinity is likely to be recorded much higher. The PM2.5 levels would also see a spike but not as much as PM10 (being larger particles than the former)."
PM10 are inhalable particles, with diameters that are generally 10 micrometres.
Experts said after the demolition, the Uttar Pradesh Pollution Control Board (UPPCB) needs to monitor the air quality levels of the site and the whole area for at least one-and-a-half months to ensure that pollution from demolition does not coincide with the annual pollution factor.
Vikrant Tongad, an environmentalist, said, "Currently, the wind is carrying the pollutants away. However, to my knowledge, we did not see a huge difference in pollution levels before and after the demolition. But the pollution is still spiking in areas close to the demolition."
Mahesh Palawat, a meteorologist, said, "The wind is currently blowing towards the northwest and the air is carrying the pollutants toward Greater Noida and parts of Uttar Pradesh."
There are chances the wind may change direction by late afternoon on August 29. As the direction changes, the wind speed will also go down for the next two-three hours, he said. However, the threat of spreading pollutants to Delhi is minimal, he added.
Experts said the chances of rain are low. In isolated cases, there may be moderate rains but that won't be enough to wash away the pollution, they said.
Kanchi Kohli, a researcher at the Centre for Policy Research, said, "There are majorly two aspects here, precaution and mitigation. When we look at environmental impact procedures, real estate projects have much less scrutiny than other infrastructural projects. And few scopes of public participation."
Experts said the Supertech demolition will pave way for such precautionary measures in the future, especially when the builders are more aware now.
Kohli said there was a need for proper planning not only for the construction but also for construction and demolition (C&D) waste.
Vashishtha said the Noida Authority needs to ensure that there is proper segregation of the waste, into concrete, steel, soil, wood, glass, plastics, bricks and mortar, etc, as provided under the Construction and Demolition Waste Management Rules, 2016, under the Environment (Protection) Act, 1986.
After segregation, they must be carefully transported under covered sheets to the C&D waste processing site, where another round of segregation must take place.
The Noida Authority must incentivise the reuse of the extracted materials in construction activity, including non-structural concrete, colony and rural roads, he added.
Experts said water sprinklers, spray guns and anti-dust guns must remain installed in adequate numbers in and around the site and used regularly till the disposal of the entire demolition waste.
The areas in the vicinity of the towers must be greened and landscaped gradually to contain the dust.The UPPCB must ensure that the provisions of the C&D Waste Rules are strictly implemented. The Central Pollution Control Board must ensure that there are no lapses by the UPPCB and Noida Authority, Vashishtha added.