Waste as a resource: green building aspects

The increasing urban clusters and increase in population has highlighted the issue of Waste management. The mounting waste is suffocating the natural habitat and putting exponential pressure on the natural environment. The natural resources are getting degraded and toxics contamination into these has a direct impact on the public health. There has become an urgent need of addressing the sustainable waste management issues properly. Urban planners must approach practical aspects of waste management.

Waste is basically unused materials and products or by products which is produced by the development process at large. As per the estimates, Indian Economy is going to have a rapid development in coming years as per its agenda as there is a development deficit of around 65% as per the current requirements. The building construction industry has a great proportion in the GDP. It produces the second largest amount of demolition waste and green house gases (around 35-40%). It also is a major consumer of energy during the construction process and for post construction needs of the occupants’ comfort viz. lighting or air conditioning systems etc. The occupants’ activities further generate a large amount of solid waste and water waste as well.

Construction and demolition waste likely plays an important part, which has not been properly even mentioned in the policy document. Developing a Waste Management Plan during the design phase itself may help us in effective planning of managing or reusing waste, which is going to landfill. During building construction activities the table below shows quantities of waste generation in percentage terms.

As almost 35-40 % of the total waste related to construction and demolition of buildings, it may provide a resource (by products) as well through recycling for the new product. Thus recycle, reduce and reuse of waste can do wonders and can provide various tangible and intangible benefits such as

• Reduce the amount of waste going to landfill thus helps in reducing ill impacts on natural environment
• Reduce emissions, pollution and contamination
• Protect scarce resources
• Reduce overall construction costs
• Reduce tipping fees
• Sell salvaged resources
• Contribute towards Green commitment

The inadequate management of solid waste and decomposing garbage especially the garden and food waste emits gases affects the local environment. Food and garden waste in Municipal Waste proportionally is increasing and possess a great concern.

Solid Waste Management process involves management of waste through collection, proper storage, segregation, transport and recycling. As per the Municipal Solid Waste Management and Handling Rules 2000, Solid waste management is the responsibility of local urban bodies. Due to lack of financial resources, institutional arrangements, inappropriate technologies, weak legislative measures and unawareness in public; it has become inefficient. Formal processing, recycling and recovery units are not established properly and it is restricted to small and medium Kabadis (Waste pickers). The illegal dumping of domestic and industrial waste is a common practice. Solid waste management is still to be addressed by policy makers and urban planners with utmost priority. Formalization of the system for collection, segregation, processing, treatment and disposal is of utmost importance to check the challenge and manage the solid waste properly. In addition to these generation of awareness about responsibly manage solid waste at micro and macro level would be of great significance.

Most of the construction and demolition material may be recycled and reused. Civil and Waste contractors and recyclers may further be involved for valuation of the same. For example some of the following material may be of great relevance and provide reuse opportunities as well;

• Steel may be melted and reused to produce new steel products. The use of recycled steel reduces the embodied energy by 72%
• Aluminum may be 100% recycled. Use of this recycled aluminum reduces embodied energy by 95%
• Gypsum plasterboard should also be recycled, since its disposal to landfill produces poisonous hydrogen sulphide.
• Timber may also be used directly or reused or turned into horticultural mulch beneficial for soil
• Concrete can be crushed and recycled and used as new concrete or road base and fills
• Glass may also be reused as aggregate for concrete.
• Plastics can often be granulated and reused to make new plastic products. Researchers are looking at plastic as a significant concrete ingredient for future sustainable construction.