Mumbai civic body’s incredible claim: We can build homes by recycling construction waste
Mumbai’s construction experts said they were sceptical of the claim as the recycling process may not generate sand and bricksmumbai Updated: Aug 10, 2017 15:57 IST
Mumbai’s municipal corporation has made an incredible claim — that it will recycle most of the 1,200 metric tons (MT) of construction wastes generated daily into building material.
Construction and demolition (C&D) waste is usually dumped at Deonar, Mulund and Kanjurmarg landfills, but a lot of it is used to illegally reclaim wetlands and mangrove forests.
Next year, the Brihanmumbai Municipal Corporation (BMC)’s solid waste management (SWM) department plans to recycle 1,140 million tonnes (95%) of this waste into clay, bricks and sand.
Construction experts said they were sceptical of the claim as the recycling process may not generate sand and bricks. They however added that it can convert C&D waste into aggregates — finer forms of concrete bricks — that can be reused by industries.
“The processing of construction debris involves breaking them into smaller parts and sieving them. What passes through the sieve is sandy material. What stays above is aggregates. Both materials can be utilised outside landfills,” said KP Niyati, former environment head, confederations of Indian industries and member of various environment impact assessment committees of the ministry of environment, forests and climate change.
The BMC has issued tenders seeking bids for the project. “We expect the tendering process to be completed over the next six months. The project should start by early 2018,” said a senior SWM official.
He said a two-hectare plot at Mulund has been allocated for the project. “We will develop two sites within this area. A one-hectare plot will be used to recycle 600 MT from the eastern suburbs and city. About 600 MT from the western suburbs will be recycled at an adjacent site,” the official said.
Niyati said the government does not need environment clearances to set up such recycling units.
“Waste that is not recycled will be left at open dumps,” said an official. He added that the recycled material will be sold back to industries. “If we do not earn enough revenue from the recycled sand or clay, the debris will be further recycled into finer aggregates and concrete blocks or bricks will be built,” he said.
The BMC’s plan comes five months after the Central Pollution Control Board (CPCB) issued draft guidelines to effectively manage C&D waste in India, for individuals and bulk generators — those who generate more than 20 tonnes a day or 300 tonnes a month.
Last year, the Union environment ministry notified the Construction and Demolition Waste Management Rules, 2016, which mandate that permissions for new constructions or redevelopment will only be granted after the local civic bodies develop their own plan to treat and recycle C&D waste and private players submit their waste management plan to the civic body and pollution control board.
According to the CPCB, India generates 14.7 million tons of C&D waste a year. This is expected to increase in the future.
Environmentalists said redevelopment projects in the city have been stalled owing to the ineffective treatment of C&D waste. “This is a good move and one that should have been initiated many years ago as construction has only been on the rise,” said Godfrey Pimenta, trustee, NGO Watchdog Foundation. “The state pollution control board needs to ensure that the bulk of C&D generators recycle their waste. This will prevent mangroves and wetlands from being destroyed through the illegal dumping of debris,” he said.
BMC officials said they will recycle two kinds of debris — unclaimed debris and debris on call — from agencies such as the Mumbai Metro Rail Corporation, Mumbai Metropolitan Regional Development Authority, private developers generating less than 20 tonnes a day and municipal works.
“According to the new rules, bulk generators need to recycle their C&D waste at the construction site. It should not be taken outside city limits,” he said.