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Following is a question by the Hon Kenneth Leung and a written reply by the Acting Secretary for the Environment, Ms Christine Loh, in the Legislative Council today (December 2):
Question:
According to the information on the web site of the Environmental Protection Department (EPD), the Highways Department (HyD) has so far made nine applications for variations in the conditions of the environmental permit (EP) granted to it by the EPD in 2009 in respect of the Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities (HKBCF) Project. One of such applications was to change the method for constructing the seawalls of the HKBCF artificial island from traditional fully-dredged to non-dredged. After that change, the seawalls of the artificial island would comprise steel cellular (SC) seawalls and rubble mound (RM) seawalls of length 5.1kilometers (km) and 1km respectively. On the other hand, it was reported last month that without submitting an application to the EPD for variations in the conditions of the EP, the HyD had changed the method for constructing part of the seawalls on the western and southern sides of the artificial island by replacing SC seawalls, as originally designed, with RM seawalls. After that change, SC and RM seawalls would be 3.6km and 2.5km long respectively. Some green groups have pointed out that even if silt curtains have been installed, compared to constructing SC seawalls, constructing RM seawalls is more likely to have construction waste used for reclamation overflowing into the sea. According to the response from HyD, EPD considered that as the change in the method for constructing the aforesaid seawalls involved no change to the environmental impact assessment (EIA) report, there was no need for HyD to apply for variations in the conditions of the EP and make public the change. In this connection, will the Government inform this Council:
(1) of the differences between the contents of the aforesaid EP after the first variation (No. EP-353/2009/A) and those of the EP after the latest variation (No. EP-353/2009/I);
(2) whether the authorities have compared the respective impacts on the water quality and marine ecosystem on the periphery of the artificial island which would be caused by the works for constructing SC seawalls and RM seawalls; if they have, of the details; whether they have assessed if constructing SC seawalls has a lower likelihood of causing water pollution than constructing RM seawalls; if they have, of the details; if not, the reasons for that;
(3) whether the EPD has drawn up guidelines on the circumstances under which the holder of an EP is required to apply for variation in the conditions of the EP in respect of change in construction method; if the EPD has, of the details; if not, the reasons for that;
(4) given that constructing SC seawalls and constructing RM seawalls are different methods of reclamation and land formation, of the rationale based on which the EPD decided that HyD was not required to (i) apply for variations in the conditions of the EP in respect of the aforesaid change in construction method, and (ii) make public the change; and
(5) given that it is stipulated in section 13 of the Environmental Impact Assessment Ordinance (Cap 499) that the Director of Environmental Protection (the Director) may, upon receipt of an application for a variation in the conditions of an EP by the EPD, amend the relevant EP without calling for an EIA report if he is satisfied that there is no material change to the environmental impact of the project with the mitigation measures in place and the project complies with the requirements described in the technical memorandum, whether the Director has, in respect of any of the aforesaid applications for variations in the conditions of the EP, requested HyD to submit an EIA report; if so, of the details; if not, the rationale based on which the Director made such a decision at that time?
Reply:
President,
From time to time, the design or method adopted for construction works has to be revised during the construction period for various reasons. The Environmental Impact Assessment Ordinance (EIAO) has provisions to vary an Environmental Permit (EP) by making application under section 13(1) of the Ordinance. Section 13(5) of the EIAO stipulates that the Environmental Protection Department (EPD) may amend the EP without calling for an environmental impact assessment (EIA) report if there is no material change to the environmental impact of the project with the mitigation measures in place; and the project complies with the requirements in the Technical Memorandum on EIA Process.
Regarding the method adopted for constructing the seawalls of the Hong Kong-Zhuhai-Macao Bridge Hong Kong Boundary Crossing Facilities (HKBCF) artificial island, the focus of environmental protection is on preventing the suspended solids generated by the works from polluting the sea. The EP issued in 2009 thus requires that silt curtains must be installed during the construction of the seawalls to prevent marine pollution. The initial design of the project was the adoption of traditional fully-dredged method for constructing the seawalls (i.e. dredging of marine sediment layer prior to backfilling with sand or rock-fill materials, followed by the construction of rubble mound (RM) seawalls (i.e. placing rocks to form the seawalls)). As dredging works will produce substantial amount of sediment, though silt curtains can prevent sea water from being polluted, the transportation of sediment may cause potential pollution and also much space is needed for their dumping. Therefore, the EP sets out a series of conditions to monitor the dredging works as well as the handling and dumping of sediment, with a view to minimising the pollution concerned.
In 2010, having considered the latest international reclamation techniques and feasibility, the project proponent (i.e. the Highways Department (HyD)) applied for variation of the EP to change the seawall construction method to a non-dredged one by replacing the original fully-dredged method with stone column installation to strengthen the sediment layer. To expedite the progress of seawall construction, the HyD also suggested the installation of steel cellular structures followed by the construction of RM seawalls on the outside, while for locations where steel cellular structures could not be installed, the RM seawalls would be constructed directly above the stone columns. Both types of seawall construction do not require dredging of sediment, both have stone columns installed, and have RM as the outer layer.
From an environmental point of view, the non-dredged seawall construction method above can avoid the generation of sediment. Compared with the original fully-dredged method, the non-dredged method is more conducive to the prevention of pollution and can also save the space for the disposal of substantial amount of sediment. As the application from the HyD complies with the requirements in respect of the variation of an EP under section 13(5) of the EIAO, the EPD and relevant statutory authorities approved the application. The conditions in relation to dredging and disposal of sediment in the EP have thus been deleted subsequently and a series of new conditions has been set out regarding the non-dredged method. The EP also requires that the HyD shall notify the EPD in writing any proposed changes in the construction sequences and/or arrangements.
My responses to the five parts of the question are as follows:
(a) Please refer to Annex for a comparison of the conditions and provisions of the two EPs, namely EP-353/2009/A and EP-353/2009/I. The variations concerned mainly involve amendment or deletion or addition of relevant conditions to reflect constructional or operational changes in the project since 2010, including the adoption of the non-dredged seawall construction method, installation of steel cellular structures for seawall construction, addition of facilities for reusing treated effluent, use of floating grouting production facilities to reduce the number of construction or transportation vessels, change in arrangements for sediment disposal, updating of the master layout plan and the laying of sand blanket before reclamation, etc.
(b) Regarding the seawall construction for the artificial island, its impact on the water quality is mainly attributed to the works in sediment dredging. As silt curtains are installed enclosing the works area, the two methods adopted for seawall construction, i.e., the construction of RM seawalls on the strengthened marine sediment layer direct or the installation of steel cellular structures followed by the construction of RM seawalls, will not have significant impact on the water quality. Both are in compliance with the requirements of the EIAO and its Technical Memorandum. As stated above, the non-dredged method adopted for constructing the seawalls has been able to reduce substantially the potential impact on water quality and marine ecosystem.
(c) The EIAO sets out provisions and explicit requirements that an application for variation of an EP may be submitted by the project proponent where necessary. Please refer to the above paragraphs for details.
(d) As explained above, the construction of RM seawalls is the original design while the combination of steel cellular structures and RM for seawall construction is a newly added method. Both are in compliance with the requirements of the EIAO and its Technical Memorandum. It is also stipulated in the EP that the HyD shall notify the EPD in writing any proposed changes in the construction sequences and/or arrangements. Faced with various technical restrictions, the HyD later needed to adopt the RM method at more locations, i.e. the construction of RM seawalls directly on the stone column. Therefore, the HyD notified the EPD in writing such changes in construction arrangement in accordance with the requirements of the EP.
(e) Under section 13(5) of the EIAO, if a project, where an application for variation of the EP has been made, involves change which will cause material change to the environment, the EPD may require the applicant to submit an EIA report. Material change in the EIAO is defined as a physical addition or alteration to a project which results in an adverse environmental impact. The nine applications for variation of the EP submitted by the HyD will not result in any adverse environmental impact and thus there is no need to require the HyD to submit an EIA report. As mentioned above, the major change in the project is to replace the original fully-dredged method with the non-dredged one for constructing the seawalls, and this variation applied for is more conducive to environmental protection.
Ends/Wednesday, December 2, 2015
Issued at HKT 18:23
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