C&D waste generation
Construction and demolition (C&D) waste is generated during the construction, renovation or demolition of buildings, roads, bridges, flyovers, subways, and so on. These activities typically generate large quantities of waste, although oftentimes data on C&D waste are not collected routinely or consistently, so most published figures are estimates which need to be interpreted with caution. Such estimates include 8211 million tonnes of C&D waste generated across the EU in 2012,2 77 million tonnes in Japan, 33 million tonnes in China and 17 million tonnes in India (all in 2010),3 and almost 7 million tonnes in each of the fast developing cities of Dubai (2011)4 and Abu Dhabi (2013)5. C&D waste often represents the largest proportion of total waste generated: for example, C&D waste accounts for 34% of the urban waste generated within OECD countries, as shown in Figure 3.1. The volume of C&D waste is also sharply increasing, reflecting the pace of infrastructure development across the world.
C&D waste composition
C&D waste not only contains a high proportion of inert materials (e.g. concrete, masonry, asphalt), but also wood, metal, glass, gypsum and plastics as well as hazardous substances such as treated wood, lead paint and asbestos from demolished old buildings.Due to the
1 821 million tonnes refers to the latest available Eurostat figure, replacing an earlier one of 531 for the EU-27 in 2009 quoted in the BIO Intelligence Services prepared for the European Commission (DG ENV) (cf. Annex A), which states,
“Data on C&D waste treatment suffer from the same gaps and inconsistencies as generation data ... C&D waste quantities are therefore likely to range between a total of 310 and 700 million tonnes per year in the EU-27.” See http://ec.europa.eu/environment/waste/pdf/2011_CDW_Report.pdf 2 Eurostat (2015). Waste statistics. See http://ec.europa.eu/eurostat/statistics-
explained/index.php/Waste_statistics
3 Guah (2013), listed in Annex A, Chapter 3, Other waste streams, under Topic Sheets, Construction and demolition waste
4 Environmental Center for Arab Towns (2013). Waste Management in Dubai.
http://en.envirocitiesmag.com/articles/pdf/waste_management_eng_art1.pdf 5 Environment Agency of Abu Dhabi (2013). Towards Integrated Waste
Management in Abu Dhabi: Annual Policy Brief. See http://www.ead.ae/wp- content/uploads/2014/03/Waste-PB-Eng.pdf
variety of materials it is important that the C&D waste be segregated at source, with each stream managed as required.
Baseline C&D waste management practices When waste management controls were first introduced in the 1970s, the illegal dumping of C&D waste was widespread. In many developed countries this continues to be an on-going problem, and in some developing countries such as India and Jordan, illegal dumping of C&D waste is approaching ‘epidemic’ proportions.6, 7 This is a major problem as such illegal dumps act as
‘magnets,’ in that their existence increases the likelihood of other waste such as municipal solid waste or even hazardous waste being dumped, which may pose a much more serious pollution risk. For this reason, the proper management of C&D waste is of critical importance within sound waste management overall.
As the bulk of C&D waste is inert, in the 1970s and 1980s this waste was typically landfilled. Over time, C&D
6 Centre for Science and Environment (2014)
7 SWEEP-Net (2010). Country report on the solid waste management in Jordan.
See http://www.sweep-net.org/ckfinder/userfiles/files/country-profiles/Country- reportJordan-En-mai2011.pdf
waste came to be diverted from landfilling to recycling, while more recently the focus has been on reuse and prevention.
C&D waste recycling
For C&D waste, in principle, high recycling rates should be relatively simple to achieve through segregating and crushing inert materials not contaminated with hazardous waste. The materials can be used as aggregate or used in the manufacture of, for example, concrete products or paving blocks. To compete in this marketplace, items produced through the crushing and sieving of C&D wastes need to meet the specifications and criteria set for ‘end of waste’.8
Other components of C&D waste can be recycled where markets exist for them. When it is clean and of good quality, untreated timber can be recycled into particleboard or fibreboard, recycled to produce wood chips or alternatively used for energy recovery. Metals such as aluminium and steel offer opportunities for recycling and plastics can be reprocessed into many different materials.
The recycling rates of C&D waste range enormously among countries. The 2011 Bios report provides a ‘best estimation’ of the 2008-09 EU average as in the range of 30 to 60%, with EU countries reporting recycling and recovery rates as high as over 90% and as low as 10%.9 In the US in 2009 approximately 40% of the C&D waste generated was reused, recycled or sent to EfW plants.10 Targets have been set across a number of countries and cities. For example, the current EU target is for a minimum of 70% of non-hazardous C&D waste to be reused, recycled or to undergo other material recovery
8 See Sections 4.3.2 and 4.3.5.
9 European Commission (2015). Waste: Construction and Demolition Waste.
http://ec.europa.eu/environment/waste/construction_demolition.htm 10 USEPA Office of Solid Waste and Emergency Response (2009). Deconstruction.
http://www.epa.gov/oswer/iwg/pilots/docs/ipco_deconstruct.pdf
(including backfilling operations in which the waste substitutes for other materials) by 2020,11 while the Construction Resource Initiatives Council introduced a series of targets, shown in the figure below, as a “global call to action” for the entire building industry under the international “Mission 2030” initiative.12, 13
Nevertheless, the primary driver within the construction industry for the increase in reuse and recycling is cost control, since these practices will generally reduce project costs through reduced disposal costs, decreased purchasing costs for new materials, and greater revenue earned from the sale of materials.14
Interest in C&D waste recycling is increasing even beyond developed countries. In the Gulf region, where major infrastructure projects are on the rise but baseline recycling levels are low – just 4% in Qatar in 201215 – several C&D waste recycling projects have been developed using the public-private partnership (PPP) model. These projects include plants established in Amman (Jordan), Kuwait, and Dubai and Sharjah (United Arab Emirates) which have been developed in the last decade and give revenue to their municipalities while reducing the extraction of natural resources, increasing life of landfills and generating employment.
In countries such as China and India where urban infrastructure development and re-development are expanding rapidly, C&D waste recycling has become a business opportunity for the private sector, but with C&D recycling rates estimated at 5% in China (2013)16 and 50% in India (2014)17, there is still some way to go to fulfil that potential.
11 European Commission (2015). Waste: Construction and Demolition Waste.
http://ec.europa.eu/environment/waste/construction_demolition.htm 12 Gratton (2013)
13 http://www.cricouncil.com/
14 USEPA (2000)
15 Ayoub, N., F. Musharavati, and H. Gabbar (2014). A Future Prospect for Domestic Waste Management in Qatar. Presented at International Conference on Earth, Environment and Life Science (EELS-2014). 23-24 December 2014, Dubai (UAE).
16 http://www.theclimategroup.org/what-we-do/news-and-blogs/construction- waste-recycling-in-china-the-climate-group-releases-new-report/
17 Ghosh, S., S. Ghosh and A. Aich (2011). Rebuilding C&D Waste Recycling Efforts in India. See http://www.waste-management-world.com/articles/print/
volume-12/issue-5/features/rebuilding-c-d-waste-recycling-efforts-in-india.
html
by 201535% 50%
by 2020 75%
by 2025
Zero waste to landfill
by 2030
Construction and demolition waste 91
18 Text prepared from information provided directly by IEISL in June 2015, and from published material. See http://www.waste-management-world.com/articles/print/
volume-15/issue-1/features/going-live-india-s-first-c-d-recycling-plant.html and http://www.cseindia.org/userfiles/NB%20Mazumdar.pdf
19 Lundesjo, G. (2011) Using Construction Consolidation Centres to reduce construction waste and carbon emissions. Guidance: Construction Logistics. WRAP. http://www.
wrap.org.uk/sites/files/wrap/CCC%20combined.pdf
India’s first C&D recycling plant in New Delhi18
The Municipal Corporation of Delhi, working in cooperation with the private sector, established a C&D recycling plant with the aims of diverting waste from landfill and developing the market for C&D waste. The plant, a public-private partnership in operation since the end of 2009, had an original design capacity of 500 tonnes per day that was expanded in 2014 to 2000 tonnes per day.
Incoming material is inspected and weighed. Plastics, metals, wood and certain other materials are separated out by both manual and mechanical means. The remaining waste is again separated, this time sorted into whole bricks for internal use and sale, large pieces of concrete and mixed C&D waste that is managed using dry processing to crush and grade the concrete and C&D waste and also wet processing for mineral processing and washing. The plant recovers products such as sand, stone and ready-mix concrete and uses these to manufacture other value-added products such as paving blocks and tiles, kerbstones and bricks. By early 2015, the plant had sold well over a million tonnes of recycled products.
Prevention and reuse of C&D waste
The recycling of C&D waste is not the ultimate objective. Thus, high recycling targets can be counter-productive. By the 2000s, in high-income countries, one common source of waste was the over-ordering of bricks and other materials for building sites, in order to avoid any delays in supply. Recycling targets provided a perverse incentive to crush and recycle any leftover raw materials, rather than to return and reuse them at another building site. This is an example of a simple waste prevention measure which pays for itself very quickly.19 Another example slightly more complex is the controlled dismantling rather than the wholesale dismantling of buildings, so that more components can be salvaged for reuse. An example of deconstruction can be found in Topic Sheet 4 on waste prevention.