Dealing with construction waste is imperative
Construction waste has a hazardous impact on earth and the natural resources that we use. A recent study at RICS Cobra 2013 Conference said that waste generation affects natural resources, environment and the health, safety and profitability of enterprises. Recent findings of a green NGO – Centre for Science and Environment (CSE) corroborated the trend. The NGO asked authorities to find immediate solutions to recycle and reuse such materials which cause serious environmental consequences.
Construction waste consists of excessive cement mix or concrete left over after completion of work or non-perishable waste such as plastics, metals, etc. The highest amount of waste generation, however, happens in the case of demolition. According to industry estimates, demolition of pucca and semi-pucca buildings on an average generates 500 and 300 kg/sq mt of waste, respectively. Of this, a large quantum of bricks, masonry, metal in the form of pipes, conduits, and material used in ventilation systems, wires, sanitary fittings, etc. arise as waste during demolition. Later, these are recovered and recycled by re-melting. Timber recovered from beams, window frames, doors, partitions and other fittings is reused.
However, wood used in construction is often treated with chemicals to prevent termite infestation. This may lead to health and other environmental problems.
Bituminous material arises from construction and repair of roads and water-proofing compounds. All these need special care and attention while recycling and disposing. However, the huge amount of solid waste gives rise to waste management issues. At present, management of such waste consists of re-use of materials procured in good condition during demolition and metals after melting them. The remaining waste can be put under non-reusable materials, which may require a landfill site. As per government guidelines, every municipal body should create a landfill site for waste disposal. As per Ministry of Urban Development guidelines, landfilling of construction and demolition waste should be done in a separate landfill where it can be stored for future use in earthwork or road projects. As per guidelines if such a site is not available, waste can be stored in a special cell at a landfill from where it can be mined for future use. But land being scarce, creation of such landfill sites remains the biggest challenge.
Recycling of waste in the long run might also save some funds. At present there is no segregation of waste across cities, leading to environmental hazards.
Recently published draft amendments carried out by the Bureau of Industry Standards (BIS) in the National Building Code (NBC) 2005 say that an increase in waste generation and improper land filling with such waste has a major impact such as ground-water pollution through leaching and other kinds of pollution such as air contamination to some extent. So what should be done? Draft amendments to NBC suggest that waste material which may be dumped in landfills could be converted into value-added products. An important approach to reduce waste and effect waste utilisation is to optimise the use of material and employ technologies for the same. Durable material and high performance technologies need lesser maintenance and offer better service life.
So proper waste planning is imperative before starting construction or demolition.
Research has proved that a huge portion of such waste every year can be used as aggregate material for construction of new structures, especially roads. Examples from developed countries such as US, UK, Germany, France and Japan, etc. suggest that construction waste is often recycled and used as aggregate in concrete. As a direct outcome, funds spent on procuring new concrete is saved to an extent. The present framework for disposal needs to be improved. To realise the full potential of all materials suitable for recycling, a process similar to that carried out in developed countries can be adopted. This includes tracking of construction waste in terms of re-use, recycling and disposal.
An elaborate system can be developed and implemented in two steps – permission of construction and demolition can go simultaneously along with permission granted for waste disposal and their reuse.
In the long term, such a policy will not just help the construction industry save costs, but will also make it an environmentfriendly industry.
•The author is MD of RICS, South Asia. He can be contacted by email at email@example.com