Large-scale demolitions in India: the case of the Supertech Twin Towers
As soon as we heard the news of two 100-meter high towers being demolished in Noida, we were appalled at the thought of the huge bulk of Malba that would be generated as a result. The Supertech Twin Towers demolition in Noida has raised many questions about illegal construction in India, the price the residents pay for it, the Supreme Court ruling to demolish the towers, and whether it is worth it in the end; however, we at Malba Project wanted to know where 45,000 tonnes of Malba will go, how it will be treated, and whether environmental and safety concerns are being kept in mind. This project also presents us with the rare opportunity to understand large-scale demolitions in India and the responsibilities of bulk waste generators in the C&D waste ecosystem.
So to unravel this mystery, Rohit Bagai (RB) from the Malba Project team spoke to Uttkarsh Mehta (UM), partner at Edifice Engineering, the company spearheading the demolition process, to get his views on the topic. Here's what he found.
RB: What is going to be the process of demolishing the towers? What are the different steps involved?
UM: The first step of the demolition process starts with preparing the building, which means breaking the internal walls and external walls. This is to ensure that the weight of the building is minimum. The next step is drilling holes in the vertical members or the structural members of the building, which are the columns and shear walls. After drilling the holes, we wrap the columns by chain-link system followed by geo-textile cloth depending upon the quantum of exposure used to carry out the process of demolition. The geo-textile material is used to minimize the impact of the blast. The quantity of explosives required on site is calculated using a test blast.
RB: What are the environmental clearances required for such a demolition?
UM: The UP (Uttar Pradesh) Pollution Control Board has provided us with a brief about the factors that need to be considered. The environmental impact study assessment consists of various parameters like dust and noise. Under these parameters, we need to report how much dust is created, how much noise is expected, and so on. These reports are made for pre-blast conditions as well as for after-blast conditions. Also, there is weekly monitoring for the levels of dust and noise.
RB: How are the dust and noise levels measured? What are the measures required to control dust pollution?
UM: There are different equipment to measure it. In our case, we have hired a third-party consultant – Ascenso Enviro Pvt. Ltd – to do that for us. They come every week with the equipment and measure the dust and noise levels.
For controlling the dust levels, we use geo-tactile sheets which are wrapped around the building and are watered at a regular interval. For days when the dust levels are slightly high, we use mist spray guns or we spray water from pipes connected to water tankers.
Since the dust is inevitable, as a precaution we have advised the neighboring residents to keep all doors and windows closed, switch off their ACs, and cover the external units of their ACs so that the dust is not sucked in.
"For days when the dust levels are slightly high, we use mist spray guns or we spray water from pipes connected to water tankers."
RB: What are the safety measures being taken on the site?
UM: Each worker has been provided with a PPE (Personal Protective Equipment) kit. In case they're working at a height, the double line safety belts are attached to them. Mostly lifts are used to commute between floors, but if a staircase is used, the barricading has been done so that they can hold it and walk around.
For the health part, we did the medicals of the workers before they entered the site and for corona, we did the Anti-gen test. Besides this, all the workers are covered under workmen compensation policy.
Because our site is active all the time, we also pay the workers for overtime and make sure they have a weekly off. But mostly we ensure active work on-site by having overlapping shifts. We also have living arrangements on site as the second, third, and fourth floors are currently occupied by us.
RB: What happens to the different materials during the demolition process?
UM: We are already maintaining registers on-site for any disposals which are currently happening. Currently, it mostly involves a little bit of wood from the shuttering materials. There is also a bit of plastic for which records are also being maintained. Both wood and plastic are salvageable materials and are sold to local vendors who take them to the local market.
Steel and debris are the two major components that are yet to be released from site.
Also after the demolition process, for the initial one and a half months, we remove the steel out of debris and then churn the debris. We try to ensure that most of the steel is removed because most of the money is recovered from that. After the steel is recovered, we need to ensure proper disposal of Malba (C&D waste) and the final clearing of the site.
The steel which will be recovered from the site, in our case, would be taken to the rolling mills in Punjab.
"Both wood and plastic are salvageable materials and are sold to local vendors who take them to the local market... The steel which will be recovered from the site, in our case, would be taken to the rolling mills in Punjab."
RB: What happens with the Malba / C&D waste?
UM: For the C&D waste, we have been provided with some guidelines according to the C&D Waste Management Rules 2016. We are in contact with the Noida authority and UP Pollution Board to decipher the best possible solution for the disposal of C&D Waste in a scientific way.
The C&D waste needs to be processed in a C&D recycling plant. Noida Authority does have a C&D plant set up with Ramky in the vicinity, but the capacity is too small for a project of this size. The quantity of Malba that the C&D plant can process is already being dumped there every day; so it will be difficult for them to accommodate the amount of Malba which will be produced by us. We will generate almost 45,000 tonnes of Malba – which I need to dispose of in a month's time, which for them will be a difficult and challenging thing to do.
"Noida Authority does have a C&D plant set up with Ramky in the vicinity, but the capacity is too small for a project of this size... We will generate almost 45,000 tonnes of Malba"
RB: Are there any other solutions being considered for the disposal of Malba?
UM: One of the ideas being considered is going for a mobile stationary unit of a certain capacity for our own project. This is one possible way of disposing, as we can downsize the Malba and then maybe someone who can buy that from us. But different factors need to be considered as we don't have much time left for the process here. Another way of doing it could be requesting the Noida Authority to give us a plot where we can take this debris, compress it and dump it there. In such a case we already have six bucket crushers with us already.
We still have a meeting planned with the UP pollution board, where we will submit the debris management plan. We are still exploring and in some time we will have the exact procedure to go ahead.
RB: How is the C&D waste management system in other cities in India? And is recycling a viable option for a bulk generator like you?
UM: C&D plants are now present in most major cities in India. For example in Delhi, we have around three or four recycling plants. Other cities like Surat, Ahmedabad, Bangalore, Pune, Bombay, Chennai and Hyderabad also have recycling plants.
We, as a generator of waste, try to dispose of our Malba in the most scientific manner; we educate our clients about this method of recycling Malba and that this is the best way to do it. But personally, I would say that it is still in a nascent state; not everyone has accepted and welcomed this system yet. Also because there is a huge cost to dispose of the Malba at a plant; and this is where the clients run away.
The business model which has been currently adopted has several hindrances in my opinion. For example in Gujarat, people need to pay in order to get their Malba transported. Even for me (as a bulk generator) I need to transport the Malba till the C&D recycling plant to them and then pay him an additional charge for processing.
For us, that means when we quote to the clients we let them know that there are two ways of disposing of the waste. The best way is to take it to a C&D Plant but there is a cost to it. The other solution is to take it to a landfill which is a harmful strategy. So then the clients get to decide and we work according to our contract.
"... Personally I would say that it (taking Malba to a recycling plant) is still in a nascent state; not everyone has accepted and welcomed this system yet. Also because there is a huge cost to dispose of the Malba at a plant; and this is where the clients run away."
RB: What is the current business model and why is it not working?
UM: Right now a C&D recycling plant earns money to process the waste and they also earn by selling the Building Materials made from processing the waste. The thing to realize is that currently there is very little margin in this. However, the companies that have set up the plants are looking at it from a future perspective. They believe that this will become a big operation down the line and at the moment are running in losses.
They believe that 5 to 10 years down the line, the Government of India will mandate people to dump the waste at the plants. By linking the C&D waste to building clearances and permissions could be one way to move ahead with this. So in case you don't have receipts for the recycling plants, then the building contractors would not be allowed to proceed with the construction. There should be some incentives for the demolition contractors to dump their waste at the recycling plant. For example in the C&D recycling plants abroad, they have a system in which the generator gets paid to dispose of their Malba at a plant which is a good incentive for a waste generator. Right now in India, it is the other way around and I don't know when this will change.
"...in the C&D recycling plants abroad, they have a system in which the generator gets paid to dispose of their Malba at a plant which is a good incentive for a waste generator. Right now in India, it is the other way around and I don't know when this will change."
RB: Do you agree with this demolition? Could there have been an alternative, in your opinion?
UM: I don't know exactly from the builder’s perspective but what I heard from the people is that it was proposed that the authority or the government can take it up and use it for their own state and not get it demolished. As for me, I'm very small to comment on this issue. But somehow I mean, it would have been good if the structure could have been saved because it's a waste of money, materials, time, and also a hassle for the people around.
"...it would have been good if the structure could have been saved because it's a waste of money, materials, time, and also a hassle for the people around."