As cities expand and indulge in construction to accommodate more people, the question of dealing with construction and demolition waste becomes increasingly critical
Indian cities are incessantly building more and more structures to accommodate more people and more activities. The range of private and public urban construction projects is large—new construction, demolition of old structures, re-modelling of old buildings and the construction of taller buildings than before. These comprise residential and commercial complexes, schools, hospitals, markets, roads, bridges, flyovers, tunnels, transportation services such as metros and monorail, footbridges, toilets, drainage works, water and sewerage work, libraries, museums, theatres, and swimming pools, to name a few.
The range of private and public urban construction projects is large—new construction, demolition of old structures, re-modelling of old buildings and the construction of taller buildings than before.
Infrastructures atrophy over time. Once they have outlived their utility, they have to be demolished and replaced with fresh infrastructure. In many instances, the rapid growth of cities has necessitated relatively new infrastructure to be pulled down to cater to the requirements of fast-growing cities with better, larger or more sophisticated levels of infrastructure. A few examples are the Pune University and e-square flyovers. Thus, the volume of construction waste generated in cities is extensive and is generally labelled as construction and demolition (C&D) waste.
Construction waste includes asphalt, cement, bricks, glass, nails, wiring, insulation, rebar, wood, plaster, sanitary ware, and scrap metal. Dredging materials or materials that need to be removed while preparing a demolition site, comprise trees, tree stumps, rocks, dirt, and rubble. In the United States, construction waste makes up one-third of the total refuse generated nationally. In India, two governmental agencies, the Building Materials and Technology Promotion Council and the Centre for Fly Ash Research and Management, estimated a national annual output of 165 to 175 million tonnes from 2005 to 2013. Some other estimates calculated that at any given construction site, 30 percent of the total weight of building materials delivered to a building site is construction waste.
In 2016, the Ministry of Environment, Forest and Climate Change brought into force the Construction and Demolition Waste Management Rules (C&D Rules) 2016 to regulate such waste. It defined construction and demolition waste as waste comprising building materials, debris and rubble resulting from the construction, remodelling, repair and demolition of any civil structure. It specified the duties of waste generators, including their prima facie responsibility for collecting and segregating concrete, soil, and other materials and storing construction and demolition waste generated. It mandated the waste generators to store the waste within their premises, get it deposited at a local authority collection centre, or hand it over to the authorised processing facilities. They also need to ensure that no waste is deposited on roads or drains.
Additionally, every waste generator was to pay for collection, transportation, processing and disposal. The rules mandated the urban local bodies (ULBs) to notify directions for appropriate disposal in accordance with the stipulated regulations and make disposal arrangements, either themselves or through appointed private operators. The ULBs were urged to create an information and communication system and seek assistance from expert institutions and civil society organisations. It also specified the duties of other governmental authorities and parastatals.
The waste that comes out of construction is detrimental to the environment. In addition, its volume is enormous. Thus, it must first be optimally utilised. What cannot be used must be disposed of in a manner that causes the least harm to the city and its environment. Such waste ought to be reduced, reused, and recycled, with a conscious attempt at source reduction. This can be done by preserving existing buildings, optimising new construction size and erecting new buildings with such adaptability that their life can be prolonged. The practice of construction methodology that enables disassembly and facilitates the reuse of materials is also desirable.
The waste that comes out of construction is detrimental to the environment. In addition, its volume is enormous. Thus, it must first be optimally utilised. What cannot be used must be disposed of in a manner that causes the least harm to the city and its environment.
Similarly, a fair amount of construction and demolition debris, including wood plastics, asphalt pavements and gravel, and aggregate products, is eminently suited for reuse. Other debris, such as wood waste, can be recycled and used for new construction. Cement, plaster, and bricks can be crushed and used for fresh buildings. Since urban construction involves diverse materials, there will still be sizeable debris that must be appropriately disposed of even after trying these reuse and recycling methods. Waste like treated timber, concrete additives, asbestos, contaminated soils, adhesives, paint, solvents and lead-acid batteries are hazardous, requiring careful and scientific disposal according to the laws specified for their handling. The management of such diverse waste is complicated and multi-dimensional. Management of construction waste, therefore, needs to be a planned activity in cities.
Surprisingly, construction waste handling in Indian cities goes largely un-administered. Rules and regulations formulated for their management are generally side-stepped, thereby adding to the monumental issues that cities face. Their role in narrowing city water bodies and exacerbating the situation of urban floods is especially grim. This is done by dumping waste, especially during night hours, by contractors of developers, along river banks. This allows a developer to cut waste disposal costs by saving on transportation to a distant site. At the same time, while the river bed is narrowed, the land that is filled up along the river banks is readied for future construction. In the event of very heavy precipitation and the overflow of rivers, buildings on such reclaimed land could crash, putting human lives at enormous risk. This was evidenced during the recent floods in Pune.
State governments are mandated to draw two flood lines along the river for their preservation. These red and blue lines are drawn on maps to indicate lands prone to flooding. The blue line indicates the maximum flood line recorded in 25 years, and the red line indicates the maximum flood line recorded in 100 years. No construction is allowed in the ‘prohibited zone’ up to the blue line. However, some public facilities are allowed to come up in the ‘restricted zone’ between the blue and red lines.
State governments are mandated to draw two flood lines along the river for their preservation. These red and blue lines are drawn on maps to indicate lands prone to flooding.
Despite these stipulations, cities have shown utter ineptitude in preventing the abuse of prohibited and restricted zones. A former Chief Minister of Maharashtra is on record admitting that a lot of construction has taken place inside the flood lines of most of the rivers in Maharashtra. The Centre of Science and Environment estimated that between 2005 and 2013, 287 million tonnes of construction and demolition waste was dumped into rivers across the country, causing untold damage to the riverine ecosystem. In the Mumbai metropolitan region, eco-sensitive Vasai and Thane Creeks and several mangrove areas have been surreptitiously used as dumping grounds. Experts have warned that disaster awaits us unless demolition waste is recycled.
Unfortunately, very few cities in the country have a construction and demolition waste recycling facility. This is despite the fact that waste recycling is a profitable business and generates reasonable returns. Besides, the C&D Rules provide for urban local bodies to use 10 to 20 percent of recycled waste in their own constructions. Additionally, it holds all the stakeholders, including the transporting contractor, the developer, the ULB and the state government, responsible for waste disposal. It makes debris recycling mandatory and dumping waste outside the designated sites illegal.
As cities expand and indulge in construction to accommodate more people, the question of dealing with construction and demolition waste will become more critical. Given the losses that floods cause to cities, it would be highly unwise not to clamp down on the illegal disposal of waste, especially in places where the egress of water is compromised.
Ramanath Jha is a Distinguished Fellow at the Observer Research Foundation.
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Dr. Ramanath Jha is Distinguished Fellow at Observer Research Foundation, Mumbai. He works on urbanisation — urban sustainability, urban governance and urban planning. Dr. Jha belongs ...
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