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HCFI Round Table Environment Expert Zoom Meeting on “Construction and Demolition Waste (C & D Waste) Management - Issues and Challenges – Part 2”

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Dr Veena Aggarwal, Consultant Womens’ Health, CMD and Editor-in-Chief, IJCP Group & Medtalks Trustee, Dr KK’s Heart Care Foundation of India    28 December 2022

December 11, 2022, Sunday 

12 noon – 1 pm

  • The Construction and Demolition industry in India is around 9 lakh crores. It is increasing rapidly and is expected to cross the agriculture industry.
  • C&D waste causes air, water and noise pollution. 
  • C&D waste management is important for both urban and rural areas.
  • Niti Aayog had estimated that the annual consumption of sand in 750 million tonnes, soil 123 million tonnes and stone (aggregate) is 2000 million tonnes.
  • Five percent of natural resources can be saved by using C&D waste recycled materials.
  • About 70% of C&D waste comprises of mixed sand and soil. But what we usually see are bricks, mortar, concrete, sand, soil; iron, wood are not seen. 
  • With newer technologies, it is now possible to process and recycle 95% of mixed C&D waste by using wet and dry processes. The products made out of sand, soil, aggregates, recycled concrete aggregates can be used in structures.
  • The C&D waste generation in India is 100 million MT.
  • In Delhi, C&D waste generation is 7000 MT. About 6500 MT per day is collected. There are 167 C&D collection sites. 5000 tonnes per day is processed. Delhi has five recycling plants. But many cities do not have recycling plants.
  • The steps in the processing of C&D waste are collection of C&D waste, transportation, weighbridge, processing (wet and dry). The processed C&D waste is used for road making (sub base) and bricks, paver blocks and kerb stones, while the silt and fine soil material is used for filling of low lying lands.
  • Processing can reduce waste to landfill by 95% thereby reducing pressure on scarce land.
  • Recycled aggregates and recycled concrete aggregates are used for making value added products such as CC blocks, CC brick pavers, tiles and kerb stones etc.
  • The way forward so that it can be enforced includes seamless integration from demolition to processing, separation of concrete and non-concrete waste and IEC activities. Government should earmark land for processing facility. The GST should be a part with other green products such as fly ash etc. For the C&D waste recycled products, the GST is 18%, whereas for fly ash it is 5%. There should be incentives for waste generator for sale of C&D waste and concessions on purchase of recycled material. 
  • Regulatory (command and control), awareness, incentives have to work together. Only then it can be successful.
  • Regulation should start at the level of the building plan. It should not be just on paper, but should be executed on field. There should be provision of penalty such as polluter pays principle.
  • The roads have to be structurally and functionally good. Road construction begins from subgrade, then granular sub base. Then the water bound macadam is put. In this place, there is very good use for C&D waste. Above this, the bitumen concrete layer is put.
  • The road design is based on road thickness and load. This depends on the strength of the soil, which is measured by CBR (California Bearing Ratio).
  • The height of C&D waste in road construction depends on CBR strength and the load (traffic volume) on that road. If the soil strength is very high, then probably lesser thickness of C&D waste is required.
  • CRRI has designed a template which is being used in many places. Challenges faced are segregation and lab testing.
  • The overall aim is to use the recycled waste material to create environmental awareness as well as to optimally use the available resources.
  • The processing charges of C&D waste are very high, hence, new material is preferably used instead of recycled products.
  • Guidelines are in place about the use of C&D waste in road construction. But availability and high cost preclude its use. It is mainly good for sub base material.
  • It has to be carefully watched during construction. Contractors are apprehensive about lack of expertise.
  • In India, the use of C&D waste is limited. Knowledge and research are not very widely circulated. There is a need for strict enforcement and awareness campaigns.
  • A recalculation of how much carbon is being saved is required. The benefits have to be quantified properly. The indirect cost benefits need to be assessed. The environment cost, climate change cost and direct cost benefit should be combined.
  • We have to see how best we can show benefit to the contractors so that they get some sort of incentive by converting to carbon credits.
  • It is important to create a demand for recycled products. Some provision about use of recycled material and its impact on design should be incorporated in IRC-37, guidelines for  pavement design. This may increase its utilization.
  • This is an area where contribution of technologists and professionals is much needed. This is not for management specialists. The situation will improve only with the use of technology. 
  • There is a need to develop new construction materials; architects/designers need to adopt these new materials.
  • Use of prefabricated materials, if developed, will make construction in urban areas very easy. Wastage will be reduced and generation of air pollutants will be negligible.
  • Technologists need to study how demolition can be carried out in the shortest time possible and with minimum of air pollution. Highly skilled professional knowledge is required. A panel of demolition experts should give an opinion on pattern of demolition. We are still dependent on local contractors and unorganized labor.
  • There is a need to strengthen the IT sector so that there is a database. It can play a great role right from the time of granting of permission to build to tracking its journey. Standardization is required.
  • At present, there is no tracking of C&D waste, which is a challenge.
  • The C&D Rules define the duties of various institutions. But this needs to be practical. We need to relook at these duties.
  • The Rules need to be amended to make them more enforceable. They do not talk of reporting by municipal corporations. Municipalities do not submit any data about the waste generated and collected. This should be linked to the passing of the building plan. 
  • Pricing of recycled products has to be defined.
  • About 10% of total new construction should have C&D recycled material. This has to be factored in the work order or contract.
  • A waste recycling facility in all existing municipal solid waste plant should be made mandatory.

 

Participants

 

Dr Anil Kumar

Dr Ravindra Kumar

Dr SK Gupta

Mr Pradeep Khandelwal

Mr Sanjiv Kumar

Mr Neeraj Tyagi

Dr S Sharma

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