LCQ2: Construction and demolition materials generated by infrastructure projects

Following is a question by Hon Chan Hak-Kan and a reply by the Secretary for the Environment, Mr Edward Yau, in the Legislative Council today (May 13):


The Chief Executive announced in his 2007-2008 Policy Address the implementation of the 10 major infrastructure projects, which will commence one after another within the next few years.  In this connection, will the Government inform this Council:

(a) of the estimated quantity of construction and demolition (“C&D”) waste to be generated by such projects in the next five years, and the respective quantities of such waste which will be transported to public fill banks for reuse and recycling, transported to the Mainland for reuse, and discarded at landfills;

(b) whether it will specify in the building contracts for such projects the quantities of C&D waste which the contractors concerned must reuse; if it will, of the details; if not, the reasons for that; and of the measures to be introduced to encourage contractors to reuse C&D waste during the construction periods; and

(c)whether it will conduct a territory-wide large-scale and comprehensive environmental impact assessment to explore the impact of the noise, water and air pollution which will be generated by such projects during the construction periods on the overall environment of Hong Kong; if it will, of the details; if not, the reasons for that?


Mr President,

(a) Construction and demolition (C&D) materials are a mixture of inert and non-inert materials arising from construction, excavation, renovation, demolition, and roadworks.  The majority of the inert C&D materials (also known as public fill) are soft inert materials such as soil, the only productive outlet of which is to be used as fill materials in reclamation and earth filling works.  As for the remaining hard materials such as rocks, broken concrete and bricks, some of them can be reused for seawalls in reclamation while others can be recycled as aggregates for concrete production or as granular materials for road sub-base.  Non-inert materials usually comprise plastic, timber, and other solid waste.

Inert C&D materials are reused and recycled as far as possible, while non-inert materials are disposed of at landfills.  According to the figures provided by the relevant policy Bureaux, it is estimated that the 10 major infrastructure projects would generate about 45.7 million tonnes of C&D materials in the next 5 years (from 2009 to 2013).  However, some of the projects are still at an early stage of planning and technical study; the relevant estimation on C&D materials is not yet available.  Of the 45.7 million tonnes, we expect 42.9 million tonnes (about 94%) to be inert C&D materials, while the remaining 2.8 million tonnes (about 6%) would be non-inert C&D materials.  The inert C&D materials would be stockpiled at public fill banks for later beneficial reuse or delivered to be reused in reclamation projects in the Mainland.

(b) According to the existing Technical Circular (Works) No. 33/2002, a Construction and Demolition Material Management Plan (C&DMMP) has to be prepared in the design stage of a large-scale public works project to consider among other measures to minimise the generation and maximise the reuse of C&D materials.  Any surplus materials should be reused in other sites or delivered to recycling facilities.  The measures, including the amount of C&D materials to be reused, are included in the works contract to facilitate implementation by the contractor.  Each works department has set up a departmental vetting committee to scrutinise the C&DMMP and to monitor its implementation during construction.  The relevant information of the C&D materials would also be set out in the funding application to the Public Works Subcommittee under the Finance Committee of the Legislative Council. 

To encourage the reuse of C&D materials by contractors, large-scale public works projects would look for work areas as far as possible to facilitate the materials to be sorted and temporarily stockpiled for later beneficial reuse.  For example, the C&D materials to be reused later as filling materials in the Kai Tak Development infrastructure works will be temporarily stockpiled within the Kai Tak area. 

(c) The 10 major infrastructure projects are Designated Projects under the Environmental Impact Assessment Ordinance (EIAO).  According to the EIAO, an environmental impact assessment (EIA) study is required and an environmental permit has to be obtained before a Designated Project can be implemented.  In addition to the environmental impact of the project itself during the construction and operation phases, the EIA study will comprehensively assess the cumulative impacts on the overall environment arising from other relevant existing and planned projects, and work out suitable mitigation measures.

The scope of the EIA study includes the combined impacts on the environment and ecology due to noise, wastewater, solid waste and air pollutants generated by the projects during the construction and operation phases.  Depending on individual requirements, the study may include assessment of visual impact, impact on antiques and monuments, as well as the hazard posed by dangerous goods.

After completion of the EIA report on the project, the relevant works department or organisation is required by law to exhibit the report for public inspection and submit it to the Advisory Committee on the Environment (ACE) for consideration.  The Director of Environmental Protection will take into account the views of the public and the ACE and ensure that the report fully complies with the statutory standards and requirements under the EIAO before giving approval to the report and issuing the environmental permit.


Ends/Wednesday, May 13, 2009
Issued at HKT 12:58