Media

Rapid development in Hong Kong and the neighbouring Great Bay Area (GBA) has resulted in a massive amount of construction waste. How to productively and efficiently use these waste will be a big challenge in the GBA.

In fact, construction waste does not need to be disposed of completely. A considerable portion can be reused or regenerated. A research team led by the University of Hong Kong (HKU) and comprising experts in civil and environmental engineering, and construction economics and management from HKU, Hong Kong Polytechnic University and Shenzhen University, has proposed forming a Waste Trade Organisation (WTO) for the 11 cities in the region to trade and share construction waste materials (CWM) in order to achieve zero waste status in the long term.

“For example, we have X tons of construction materials and alert others. Someone somewhere in the region says we want it. We can then calculate the logistics flow through big data analytics via a platform, and ship our materials there without having to dump it in the landfills in Hong Kong.” said Dr. Wilson W.S. Lu, the project’s Principal Investigator and Associate Professor in the Department of Real Estate and Construction at HKU.

There have been examples of cross-region disposal of construction waste in recent years. Guangdong’s Taishan has used reusable construction waste from Hong Kong to generate 660 hectares (ha) of new land, or nearly one-tenth of the area of Hong Kong Island (7,859 ha). Shenzhen also disposed around 20% of its construction waste to nearby cities, where the labour cost is much lower, for further sorting, reuse, recycling or disposal.

When properly managed, CWM can be transformed into useful materials for building and construction activities. In the Netherlands, Japan and Singapore, CWM is one of the most popular materials for land reclamation. Rocks and aggregates recycled from CWM are used for highway construction and land reclamation in the US and Taiwan. In Japan, UK and some European countries, they are recycled into bricks and high-strength flooring materials for building purposes.

The construction industry in the GBA has put in great efforts to combat the construction waste crisis. Hong Kong has been actively trying new CWM policies based on the latest waste management philosophies introducing measures to reduce, reuse, and recycle waste materials, and advocating a “polluter pays” principle. After a decade of development, the Hong Kong Government has made it mandatory for all non-reusable and non-recyclable construction waste be disposed of at government waste facilities such as landfills. For each ton of these waste to be dumped at landfills, the main contractors have to pay a levy (HK$200 per tonne since 2017). Other places in GBA have similar charging schemes.

Despite these policies, the amount of construction waste is still daunting. Over the past 10 years, Hong Kong has generated a yearly average of 19.8 million tonnes of CWM. The total CWM generated amounted to over five Tseung Kwan O Landfills. With major infrastructure projects such as the HK-Zhuhai-Macao Bridge, the High Speed Rail and large public housing projects in recent years, the amount of waste has steadily increased. Other neighbouring cities also encountered similar problems. In 2016, Guangzhou’s construction waste has risen to 7.27 million m3, in which less than 3% had been recycled and reused. In Shenzhen, the amount of construction waste reached 14.60 million m3 in 2016.

Construction waste materials are generally classified into two categories: inert and non-inert. The former refers to material which have minimal or no chemical or biological activity such as debris, rubbles, earth, bitumen, and concrete. They can be recycled into bricks, blocks or aggregates for concrete production, site formation, and land reclamation etc. In Hong Kong, over 90% of construction waste is inert.

On the contrary, due to its non-combustible and unstable nature, non-inert materials such as bamboo, plastics, glass, wood, paper, and vegetation, are not suitable for incineration, land reclamation, or other reuse or recycling and must be placed in landfills. In Hong Kong, 25-30% of all solid waste in landfills are non-inert construction waste.

Construction waste not only poses a challenge to land scarcity, but also raises safety and environmental concerns. In 2015, a colossal illegal construction waste dump accumulated over two years in Shenzhen’s Guangming New District collapsed, killing 70 people and crushing over 30 buildings.

Dr Lu believes sharing construction waste across the cities presents a win-win situation for both the giving and receiving parties. It is also considered to be a more environmentally-friendly option since resources need not be spent on purchasing virgin materials.

The Waste Trade Organisation (WTO) aims to propose evidence-based policy recommendations to overcome the existing administrative, technical, economic, and environmental barriers regarding construction waste in the region due to unclear specifications around sharable/tradable waste, difficulty in accessing information and understanding stakeholders’ assets and needs, as well as high transaction costs.

The team’s preliminary recommendations include:
- Develop specifications to clarify construction waste as reusable/recyclable materials for sharing
- Use “green labels” to qualify construction waste as sharable/tradable “regular product”
- Establish a GBA-level information sharing platform to allow real time construction waste demand and supply exchange.
- Develop different policies options in individual regions, e.g., taxation, subsidy, or non-tariff measures to encourage cross-region sharing

The project is funded by the Policy Innovation and Co-ordination Office’s Strategic Public Policy Research Funding Scheme.

About the research team
Dr. Wilson W.S. Lu, Associate Professor in the Department of Real Estate and Construction at the University of Hong Kong. As principal investigator of this joint university research project, Dr Lu is a leading authority in construction waste management research. He has been studying the issue for over a decade and conducted countless interviews with government officials and industry practitioners across the Great Bay Area. His previous research included construction waste management in Hong Kong and Mainland China with a focus on its managerial, economic, and policy facets, including tracing illegal dumping using big data

Professor C.S. Poon, Chair Professor of the Department of Civil and Environmental Engineering, Hong Kong Polytechnic University. A world-renowned figure in construction waste management research, Professor Poon will discuss the chemical and engineering aspects of construction waste and its application in land reclamation.

Professor Jiayuan Wang, Dean of the College of Civil Engineering at Shenzhen University will present ideas for waste minimization, sustainability as well as legislative reform across the Great Bay Area.

The research team also include other experts from universities in Mainland China, e.g., Sun Yet-sen University, Guangzhou University.

For media enquiries, please contact:
Communications and Public Affairs Office, HKU
Ms Trinni Choy (Tel: 2859 2606/ Email: pychoy@hku.hk)
Ms Rashida Suffiad (Tel: 2857 8555/ Email: rsuffiad@hku.hk)
Ms Melanie Wan (Tel: 2859 2600/ Email: melwkwan@hku.hk)