LCQ20: Three-runway system at Hong Kong International Airport
Hong Kong (HKSAR) - Following is a question by the Dr Hon Yiu Chung-yim and a written reply by the Secretary for Transport and Housing, Professor Anthony Cheung Bing-leung, in the Legislative Council today (May 17):
According to a paper submitted by the Airport Authority (AA) to this Council, marine sand from the Pearl River Delta Region will be used for the reclamation works under the project of the expansion of the Hong Kong International Airport into a three-runway system (3RS reclamation works). However, it has been reported that the contractor concerned has failed to source sufficient marine sand for the reclamation works and therefore has switched to use mechanical sand (i.e. sand made by crushing rubbles with machines).
Some environmental groups have pointed out that the large amount of fine particles contained in mechanical sand are difficult to settle and will therefore be suspended in the sea for a long period of time, causing an unacceptable level of pollution to the waters in the vicinity of the reclamation area. In this connection, will the Government inform this Council:
(1) whether it knows if AA has permitted the contractor of the 3RS reclamation works to wholly or partially switch to use mechanical sand for the reclamation works; if AA has, of the quantities of mechanical sand that has been and will be used as well as their respective percentages in the total quantity of sand needed for the reclamation works;
(2) whether it knows the respective places of origin of the marine sand and mechanical sand currently used for the 3RS reclamation works;
(3) whether the Environmental Protection Department (EPD) knows that the contractor of the 3RS reclamation works has switched to use mechanical sand for the reclamation works; whether such practice (i) complies with the requirements set out in the relevant environmental permit and (ii) requires the approval of the Director of Environmental Protection; if approval is required, whether the Director has granted such approval; whether EPD has assessed the immediate and potential impacts of such practice on the environment; if so, of the outcome; and
(4) of the manpower currently deployed by EPD to monitor the 3RS reclamation works; the number of site inspections, conducted by EPD officers from January 1 to March 31 this year, of the 3RS reclamation works?
The reclamation works for the three-runway system (3RS) of Hong Kong International Airport (HKIA), which involves the formation of around 650 hectares of land and requires an estimated 100 million cubic metres of filling materials, commenced in November 2016. In response to the questions raised by the Dr Hon Yiu Chung-yim, our consolidated reply with input from the Environmental Protection Department (EPD) is as follows:
(1) We understand that the Airport Authority Hong Kong (AAHK) contracted out the reclamation works through open tender.
The tender documents set out that the selected contractors are responsible for sourcing the required filling materials. The tender documents do not specify the type(s) of filling materials to be used in the reclamation works, but specific requirements on the filling materials are prescribed in the contracts in terms of particle size distribution, etc. The Environmental Permit (EP) for the 3RS project also sets out stringent requirements on the fines content of the filling materials.
For the purpose of mitigating any possible impact on water quality during construction of the 3RS project, Condition 2.26(i) of the EP stipulates that "a maximum of 10% fines content shall be adopted for sand blanket and 20% fines content for marine filling below +2.5 mPD (metres above Principal Datum) prior to substantial completion of seawall."
Although the tender documents specify that the sourcing and procurement of filling materials are the responsibilities of the contractors, AAHK has carefully studied the possible sources of filling materials and conducted market research before tendering out its reclamation works. Generally speaking, there are three types of filling materials that can fulfil the 3RS reclamation requirements for marine filling below +2.5 mPD, namely, marine sand, manufactured sand and suitable filling materials from works sites in Hong Kong. Market research shows that the latter two types of filling materials are limited in supply but there would be sufficient marine sand from sources within the Pearl River Delta (PRD) as well as from within the region for the 3RS project.
As at end of April 2017, about two million cubic metres of filling materials have been used in the reclamations works of the 3RS project, of which around 23 000 cubic metres were marine sand; 20 000 cubic metres were suitable filling materials from works sites in Hong Kong; and the remaining were manufactured sand.
As the procurement of filling materials is done by the reclamation contractors, AAHK is not able to predict the amount of manufactured sand that will be used by the contractors in the reclamation works.
(2) According to documents provided by the contractors, AAHK advised that the manufactured sand and marine sand were imported by the contractors from the PRD region and Vietnam respectively.
(3) As aforementioned, the EP issued by EPD for the expansion of HKIA into 3RS sets out the quality requirements for filling materials. Of which, a maximum of 10 per cent fines content shall be adopted for sand blanket, and there is no specification on whether the filling materials should be marine sand or manufactured sand. The EP also requires that silt curtains should be installed around the construction site to avoid adverse impact on the surrounding water body.
In addition, the EP requires the AAHK to regularly submit environmental monitoring and audit (EM&A) reports to EPD. The Environmental Team of AAHK responsible for EM&A work has been ascertaining the compliance of the EP requirement for the contractors' filling materials through testing of sand samples conducted by independent accredited laboratory. The EPD also conducts random inspections of the sand sample testing results.
As of March this year, no violation of the above requirement has been found.
(4) The Regional Office (South) of EPD is responsible for surveillance of the construction works of the 3RS project against the relevant pollution control legislation. During the period from January 1 to March 31, 2017, the Regional Office (South) conducted 13 surprise inspections on the construction works of the 3RS project.
Published on: 2017-05-17
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