TABLE OF CONTENTS

6       Waste Management Implications. 6-1

6.1      Introduction. 6-1

6.2      Environmental Legislation, Standards and Guidelines. 6-1

6.3      Assessment Methodology. 6-5

6.4      Identification and Evaluation of Wastes Implications. 6-5

6.5      Mitigation of Adverse Environmental Impacts. 6-14

6.6      Evaluation of Residual Impacts. 6-23

6.7      Environmental Monitoring and Audit Requirements. 6-23

6.8      Conclusion. 6-23

 

 

List of tables

Table 6.1      Summary of Estimated Quantities of C&D Materials Generated during Construction Phase. 6-6

Table 6.2     Original and Revised Sampling Location IDs for the Assessment 6-11

Table 6.3     Summary of Chemical Screening Results. 6-12

Table 6.4     Summary of Biological Screening Results. 6-12

Table 6.5     Estimated Quantities of Sediment under each Disposal Option  6-13

Table 6.6     Summary of Estimated Waste Arising and Recommended Disposal 6-20

 

 

LIST OF FIGURES

Figure 6.1

Proposed and As-built Sediment Sampling Locations

 

 

LIST OF appendiCES

Appendix 6.1

Sediment Sampling and Testing Plan (SSTP)

Appendix 6.2

Summary of Chemical Screening Results and Disposal Options

Appendix 6.3

Summary of Biological Screening Results

Appendix 6.4

Laboratory Analytical Report (Chemical Screening)

Appendix 6.5

Laboratory Analytical Report (Biological Screening)

Appendix 6.6

Details of Sediment Quantity Estimation

 

 

 

6                    Waste Management Implications

6.1                Introduction

6.1.1           This section identifies the types of wastes that are likely to be generated during the construction and operation phases of the Project, and evaluates the potential environmental impacts that may result from handling, transport and disposal of these wastes. The criteria and guidelines for assessing waste management implications are outlined in Annex 7 and 15 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM). The waste management implications have been assessed in accordance with the requirements outlined in Annex 7 and Annex 15 of the EIAO-TM as well as the requirements set out under Clause 3.4.6 of the EIA Study Brief (No. ESB-357/2022).

6.1.2           The assessment has taken into consideration the latest project layout, including the proposed breakwaters alignments with marine access in the form of landing facilities, the proposed land access and proposed wave wall in the form of floating breakwater, as discussed in Section 2 and as shown in Figure 2.1.

6.1.3           Mitigation measures and good site practices, including waste handling, storage, collection and disposal, have been recommended with reference to the applicable waste legislation and guidelines. 

6.2                Environmental Legislation, Standards and Guidelines

6.2.1           The criteria and guidelines for assessing waste management implications are outlined in Annex 7 and 15 of the EIAO-TM.

6.2.2           The following legislation, which has been used in assessing potential impacts, relates to the handling, treatment and disposal of wastes in the Hong Kong SAR:

·       Waste Disposal Ordinance (Cap. 354);

·       Waste Disposal (Chemical Waste) (General) Regulation (Cap.354C);

·       Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap.354N);

·       Land (Miscellaneous Provisions) Ordinance (Cap.28);

·       Public Health and Municipal Services Ordinance (Cap.132) - Public Cleansing and Prevention of Nuisances Regulation; and

·       Dumping at Sea Ordinance (Cap. 466).

Waste Disposal Ordinance

6.2.3           The Waste Disposal Ordinance (WDO) (Cap. 354) prohibits the unauthorised disposal of wastes. Construction waste, defined under Cap. 354N of the WDO means any substance, matter or thing that is generated from construction works and abandoned, whether or not it has been processed or stockpiled before being abandoned, but does not include any sludge, screenings or matter removed in or generated from any desludging, desilting or dredging works.  Under WDO, waste should be disposed of at designated waste disposal facilities licensed by the Environmental Protection Department (EPD).

Waste Disposal (Chemical Waste) (General) Regulation

6.2.4           Under the WDO, the Chemical Waste (General) Regulation (Cap. 354C) provides regulations for chemical waste control, and administers the possession, storage, collection, transport and disposal of chemical wastes.  EPD has also issued three statutory guidelines:  A Guide to the Chemical Waste Control Scheme (2016) to introduce and explain the legislative controls over the management of chemical waste in Hong Kong; A Guide to the Registration of Chemical Waste Producers (2016) to introduce the registration provisions of the Waste Disposal (Chemical Waste) (General) Regulation (the Regulation) and the procedure for identifying chemical waste generation; and the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992), which details how the chemical waste producers should comply with the regulations on chemical waste.

Waste Disposal (Charges for Disposal of Construction Waste) Regulation

6.2.5           Under the Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap.354N), construction waste delivered to a landfill for disposal must not contain more than 50% by weight of inert material.  Construction waste delivered to a sorting facility for disposal must contain more than 50% by weight of inert material, and construction waste delivered to a Public Fill Reception Facility (PFRF) for disposal must consist entirely of inert material.

Land (Miscellaneous Provisions) Ordinance

6.2.6           The inert portion of construction and demolition (C&D) materials (including rocks, soil, broken concrete, building debris, etc.) may be taken to PFRFs.  PFRFs usually form part of land reclamation schemes and are operated by the Civil Engineering and Development Department (CEDD) and others.  The Land (Miscellaneous Provisions) Ordinance requires that individuals or companies who deliver public fill to the PFRFs are required to obtain Dumping Licences. The licences are issued by CEDD under delegated authority from the Director of Lands.

6.2.7           Individual licences and windscreen stickers are issued for each vehicle involved.  Under the licence conditions, PFRFs will only accept soil, sand, rubble, brick, tile, rock, boulder, concrete, asphalt, masonry or used bentonite. In addition, in accordance with paragraph 12 of the Development Bureau (DevB) Technical Circular (Works) TC(W) No.6/2010, Public Fill Committee (PFC) will advise on the acceptance criteria.  The material will, however, be free from marine mud, household refuse, plastic, metal, industrial and chemical wastes, animal and vegetable matter and any other materials considered unsuitable by the public fill reception facility supervisor.

Public Health and Municipal Services Ordinance

6.2.8           The Public Cleansing and Prevention of Nuisances Regulation (Cap. 132) under the Public Health and Municipal Services Ordinance provides control on dumping of litter in public places.

Dumping at Sea Ordinance

6.2.9           The Dumping at Sea Ordinance (DASO) came into operation in April 1995 and empowers the Director of Environmental Protection (DEP) to control the disposal and incineration of substances and particles at sea for the protection of the marine environment.  Under the Ordinance, a dumping permit from the DEP is required for the disposal of regulated substances within and outside the waters of Hong Kong.  The permit contains terms and conditions which include the following specifications, but not limited to:

·       Type and quantity of substances permitted to be dumped;

·       Location of the disposal grounds;

·       Requirement of equipment for monitoring the disposal operations; and

·       Environmental monitoring requirements.

6.2.10        Marine disposal of any dredged/excavated sediment is subject to control under the DASO.  Dredged/excavated sediment destined for marine disposal is classified based on its contaminant levels with reference to paragraph 4.2.1 of Chapter 4 of the Project Administration Handbook for Civil Engineering Works (PAH) (subsumed from the Environment, Transport and Works Bureau Technical Circular (Works) No. 34/2002 – Management of Dredged/Excavated Sediment (ETWB TCW No. 34/2002)). The PAH and ETWB TCW No. 34/2002 stipulated sediment quality criteria or Chemical Exceedance Levels (CEL) for contaminants including metals, metalloid and organic pollutants.

6.2.11        Considering that the sediment related assessment under the EIA study, including EPD’s approval of the Sediment Sampling and Testing Plan (SSTP), and chemical and biological tests, were conducted from 2022 to early 2023 in accordance with the ETWB TCW No. 34/2002 (i.e. prior to the update of PAH), this report was prepared in accordance with the requirement stipulated in ETWB TCW No. 34/2002.

Environmental Guidelines

6.2.12        Environmental guidelines that are related to waste management practices for the Project include:

·       Works Branch Technical Circular (WBTC) No. 2/93, Public Dumps;

·       WBTC No. 2/93B, Public Filling Facilities;

·       WBTC No. 12/2000 Fill Management;

·       DevB TC(W) No. 6/2010, Trip-ticket System for Disposal of Construction and Demolition Materials;

·       Section 4.1.3 of Chapter 4 of the Project Administration Handbook for Civil Engineering Works (PAH), Management of Construction/Demolition Materials including Rocks;

·       CEDD TC No. 11/2019 ‘Management of Construction and Demolition Materials’.

·       ETWB TCW No. 19/2005 Environmental Management on Construction Sites;

·       ETWB TCW No. 34/2002 – Management of Dredged/Excavated Sediment;

·       DEVB TCW No. 08/2010 Enhanced Specification for Site Cleanliness and Tidiness;

·       DEVB TCW No. 09/2011 Enhanced Control measures for Management of Public Fill;

·       Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992), EPD;

·       A Guide to the Chemical Waste Control Scheme (EPD).

6.2.13        The WBTC No. 2/93, ‘Public Dumps’ documents the current policy related to the disposal of C&D materials. C&D materials that are wholly inert, i.e. public fill, should be taken to PFRFs for reuse instead of being disposed of at landfill.

6.2.14        In accordance with the DevB TCW No. 6/2010 ‘Trip Ticket System for Disposal of Construction and Demolition Materials’, for all contracts that are expected to generate inert C&D materials (e.g. soil, broken rock, broken concrete and building debris, etc.) requiring disposal from site, the project office shall write to the PFC through Secretary of the PFC to request a designated disposal ground for incorporation into the tender documents.  For contracts where the estimated amount of non-inert C&D materials requiring disposal at landfill facilities equals or exceeds 50 m3, the project office shall seek confirmation from the DEP in terms of the availability of landfill facilities for disposal of such materials.  The DEP will designate landfill facilities, if available, for the contract.  Where the estimated amount of non-inert C&D materials to be generated from the contract is less than 50 m3, the project office is not required to apply to DEP for designated landfill facilities.  However, the project office should still specify in the tender documents of the appropriate landfill facilities for disposal.

6.2.15        Further measures have been introduced under Paragraph 4.1.3 of Chapter 4 of the PAH to enhance the management of C&D materials, and to minimise its generation at source. The enhancement measures include:

·       Drawing up a Construction and Demolition Materials Management Plan (C&DMMP) at an early design stage to minimise C&D materials generation and to encourage proper management of such materials;

·       Vetting of the C&DMMP prior to upgrading of the project to Category A in the Public Works Programme; and

·       Providing the contractor with information from the C&DMMP in order to facilitate the preparation of Waste Management Plan (WMP) and to minimise C&D materials generation during construction.

6.2.16        The ETWB TCW No. 19/2005 Environmental Management on Construction Sites introduces additional measures to enhance waste management on construction sites. The circular sets out the policies and procedures that require the contractors to prepare and implement an Environmental Management Plan (EMP), which includes the WMP to encourage on-site sorting of C&D materials and to minimise generation of C&D materials during the course of construction.

6.2.17        The PAH and ETWB TCW No. 34/2002 sets out the procedure for seeking approval to and the management framework for marine disposal of dredged/excavated sediment.  The guideline / circular outline the requirements to be followed in assessing and classifying the sediment and explains the marine disposal arrangement for the classified material. The sediment quality criteria for the classification of sediment were referred as the Lower Chemical Exceedance Level (LCEL) and Upper Chemical Exceedance Level (UCEL). The LCEL and UCEL are presented in Appendix 4.28 of PAH and Appendix A of ETWB TCW No. 34/2002. Subject to the results of the chemical screening, biological screening may be required to determine the disposal requirement of the sediment.  There are three types of disposal options for dredged / excavated sediments stipulated in the relevant guidelines:

·       Type 1 – Open Sea Disposal or Open Sea Disposal in Dedicated Sites;

·       Type 2 – Confined Marine Disposal; and

·       Type 3 – Special Treatment / Disposal.  For Type 3 disposal, the project proponent shall be responsible for identifying and agreeing with the DEP the most appropriate treatment and/or disposal arrangement. 

6.3                Assessment Methodology

6.3.1           The assessment of waste management implications arising from the construction and operation phases of the Project has been undertaken in accordance with Appendix E of the EIA Study Brief (No. ESB-357/2022) and criteria given in Annexes 7 and 15 of the EIAO-TM, and includes the following tasks:

·       Identification and estimation of the types, quantities, qualities and timing of the wastes generated;

·       Evaluation of opportunities for waste reduction, re-use and recycling;

·       Identification of disposal options for each type of wastes;

·       Assessment of potential environmental impacts arising from the waste management with respect of potential hazards, air and odour emissions, noise, wastewater discharges and public transport; and

·       Assessment of impacts caused by handling, collection, transportation and re-use / disposal of wastes.

6.4                Identification and Evaluation of Wastes Implications

Construction Phase

6.4.1           The construction works are anticipated to be carried out between 2026 and 2030.  The major works items for the Project are discussed in Section 2 and includes the following:

(i)         Proposed eastern breakwater, approximately 340 metre (m) in length, pointing to southwest with about 50 m tip bending southward, with open space and proposed marine access in form of public landing facilities (i.e. landing steps / ramp) and associated seabed stabilisation works;

(ii)       Proposed western breakwater, approximately 300 m in length, pointing to northeast with about 85 m tip bending northward, with landing facilities for maintenance purpose and associated seabed stabilisation works;

(iii)     Proposed land access, approximately 240 m in length, connecting the proposed eastern breakwater to Tai Shue Wan waterfront along the rocky shoreline within the Project boundary;

(iv)      Proposed wave wall in the form of floating breakwater of about 110 m in length in the sea area within the Aberdeen Typhoon Shelter (ATS) expansion area at a location approximately 70 m eastward of the tombolo between Yuk Kwai Shan and Ap Lei Pai;

(v)       Modification of the crest of existing eastern breakwater to form a new open space with pedestrian access to Shum Wan Road; and

(vi)      Modification of the existing western breakwaters, which includes shortening of the breakwater by approximately 70 m with a view to straightening the navigation channel.

6.4.2           The following waste types are anticipated to be generated during the construction phase of the Project:

·       C&D materials;

·       Chemical wastes;

·       Floating refuse;

·       General refuse; and

·       Dredged sediments.

Construction and Demolition Materials

6.4.3           C&D materials would be generated mainly from general construction works and shortening of the existing breakwater.  The C&D materials would both comprise inert C&D materials (e.g. soil, rock and concrete, etc.) and non-inert C&D materials (e.g. vegetation, papers, plastics, packaging materials etc.).  Based on the latest design information, it is estimated that a total of approximately 25,000 m3 of C&D materials would be generated during construction phase of the Project.  A summary of the C&D materials estimates during construction phase is shown in Table 6.1.

Table 6.1    Summary of Estimated Quantities of C&D Materials Generated during Construction Phase

Inert C&D Materials (m3)

Non-inert C&D Materials (m3)*

Total C&D Materials (m3)

Inert C&D Materials to be Reused On Site

Inert C&D Materials to be Beneficially Reused in Other Projects

22,400

1,600

1,000

25,000

Note:

*       The non-inert C&D materials would be reused and recycled before disposal of at landfill.

6.4.4           The inert C&D materials should be reused on-site to minimise the net amount of inert C&D materials generated from the Project.  It is estimated that approximately 22,400 m³ of inert C&D materials (mainly soil) could be reused on-site as backfill materials whilst approximately 1,600 m³ of surplus inert C&D materials would be delivered to PFRF for beneficial reuse in other projects.  It is proposed to deliver the surplus inert C&D materials to Tuen Mun Area 38 Fill Bank for beneficial reuse in other projects by marine transport via East Lamma Channel, Western Fairway, Ma Wan Fairway, Ha Pang Fairway, Castle Peak Fairway and Urmston Road Fairway. As there will be two work fronts with one barge working at each work front, it is assumed that a maximum of about 2 barge trips per day will be sufficient to deliver these materials to PFRF during construction phase[1].

6.4.5           An estimated 1,000 m³ of non-inert C&D materials will be generated during construction and will be reused or recycled whenever possible. Remaining non-inert C&D materials will be disposed of at the West New Territories (WENT) Landfill. A maximum of one barge trip and/or one truck trip per day[2] provides sufficient capacity for the anticipated disposal needs. The barge route runs from ATS to Rambler Channel Typhoon Shelter, with onward transport by truck via Kwai Yue Street, Kwai Tai Road, Kwai Tsing Road, Tsuen Wan Road, New Territories Circular Road, Lung Mun Road, Lung Kwu Tan Road and Nim Wan Road. Alternatively, the truck route runs directly from ATS via Shum Wan Road, Nam Long Shan Road, Wong Chuk Hang Road, Route 1, Route 3, Tuen Mun Road, Lung Mun Road, Lung Kwu Tan Road and Nim Wan Road.

6.4.6           The waste collection frequency and transportation routes would be reviewed and subject to the actual operation of the construction activities.  Land and marine transport should be used to deliver and dispose of the waste generated from the Project to the designated disposal outlets.  No barging points, conveyor systems nor stockpiling areas would be established in the Project site.  

6.4.7           It is the Contractor’s responsibility to separate the inert and non-inert C&D materials on-site.  The non-inert C&D materials would be disposed of at strategic landfill by barge and/or truck and surplus inert C&D materials will be transported to the PFRF by barges.  A C&DMMP would be prepared in accordance with Section 4.1.3 of the PAH and submitted to PFC for approval in the detail design stage.  With the implementation of proper management for C&D materials and good site practices, no unacceptable environmental impacts (including potential hazard, air and odour emissions, noise and wastewater discharges) and public transport impact due to handling and disposal of C&D materials arising from the Project would be anticipated.

Chemical Waste

6.4.8           The maintenance and servicing of construction plants, equipment and machineries would generate a negligibly small amount of chemical wastes, for instance, oil / grease, cleaning fluids, solvents, lubrication oil and fuel, used oil filter and scrap batteries.  Since the construction activities would be carried out in the Aberdeen Channel, chemical wastes arising during the construction phase may pose environmental, health and safety hazards if not stored and disposed of in an appropriate manner as stipulated in the Waste Disposal (Chemical Waste) (General) Regulations (Cap. 354C).

6.4.9           It is difficult to quantify the amount of chemical waste that would arise from the construction activities as it would be highly dependent on the Contractor’s on-site maintenance activities and the quantity of plant and equipment utilised.  However, it is anticipated that the quantity of chemical waste would be in the order of a few cubic metres per month.  The amount of chemical waste to be generated would be quantified in the WMP to be prepared by the Contractors. 

6.4.10        Materials classified as chemical waste shall require special handling and storage arrangements by the Contractor.  Unused chemical or those with remaining functional capacity would be reused and recycled on site or by licensed companies whenever possible.  Remaining chemical waste shall be collected by a licensed collector and be disposed at a licensed chemical waste treatment and disposal facility such as Chemical Waste Treatment Centre (CWTC) at Tsing Yi. A maximum of one barge trip and/or one truck trip per day provides sufficient capacity for the anticipated disposal needs. The barge route runs from ATS to Rambler Channel Typhoon Shelter, with onward transport by truck via Kwai Yue Street, Kwai Tai Road, Kwai Tsing Road and Tsing Yi Road. Alternatively, the truck route runs directly from ATS via Shum Wan Road, Nam Long Shan Road, Wong Chuk Hang Road, Route 1, Route 3, Kwai Tsing Road and Tsing Yi Road. Mitigation and control requirements for chemical wastes are detailed in Section 6.5.9. Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements and the Code of Practice on Packaging, Labelling and Storage of Chemical Wastes published by EPD, adverse environmental impacts (including potential hazard, air and odour emissions, noise, wastewater discharge and ecology) and public transport impact will be negligible.

Floating Refuse

6.4.11        Floating refuse (i.e. food scraps, plastics, waste paper and empty containers etc.) may be generated by the construction workforce while working on/near the sea. Additionally, accidental losses of construction materials and wastes when transporting to and from the designated sites might occur.  Nevertheless, with proper waste management and training, floating refuse generated from the Project under these events is not expected.

6.4.12        On the other hand, floating refuse not generated from the Project may wash up onto the Project area through the effect of wind and currents, and may be trapped and accumulated along the shoreline and breakwaters, especially in summer months following heavy rains and typhoons.  As advised by Marine Department (MD), there was no available record of floating refuse collected within the Aberdeen Channel and based on the current condition of the existing breakwaters and shoreline within the Project area, the floating refuse to be trapped is expected to be limited.  Moreover, the proposed wave wall has been designed as a form of floating breakwater which minimise the effect to the water flow and thus the floating refuse accumulation. With reference to the approved EIA Report for Expansion of Hong Kong International Airport into a Three-Runway System (Register No.: AEIAR-185/2014) and Tung Chung New Town Extension (Register No.: AEIAR-196/2016), it is estimated that 11.5 m3 of floating refuse would be collected from the 3.4 km long artificial seawall during each year of construction.  Considering the total length of the newly constructed breakwaters and wave wall in the form of floating breakwater is approximately 1.3 km, it is anticipated that about 4.4 m3 of floating refuse could be collected during each year of construction as a conservative estimate.

6.4.13        During the construction phase, the Contractor will be responsible for the collection of any refuse within the works area.  In case of floating refuse is identified, the floating refuse shall be removed, and stored and dispose of together with the general refuse, after separating the recyclables for recycling.  The transportation routing and frequency of the barges / trucks involved for disposal of general refuse is provided in Section 6.4.15. With implementation of proper refuse collection practice and the mitigation measures as detailed in Section 6.5.10 - 6.5.11, no adverse environmental impact with regard to floating refuse would be anticipated during construction phase, or after completion of the Project.

General Refuse

6.4.14        General refuse comprising food waste, plastic bottles, aluminium cans, waste papers etc. would be generated by the workforce during the construction period.  The maximum number of construction workers to be working on site at any one time was estimated to be about 400.  Based on a generation rate of 0.65 kg per worker per day, the daily arising of general refuse during the construction period would be about 260 kg.  Therefore, it is estimated that around 960 m3 of general refuse[3] would be generated during the construction phase. Recyclable materials such as paper, plastic bottles and aluminium cans will be separated for recycling in order to reduce the quantity of general refuse to be disposed of at landfill. It is expected that the remaining non-recyclable general refuse from construction sites would be disposed of at WENT Landfill.

6.4.15        The general refuse will be generated during construction and will be collected on-site on a daily basis, separately from C&D materials by an appropriate waste collector to be employed by the Contractor. Prior to disposal off-site, such refuse will be temporarily put in suitably covered storage areas / bins where they will have to be regularly cleaned and maintained to avoid attracting vermin and pests.  The general refuse would be disposed of at WENT Landfill. A maximum of one barge trip and/or one truck trip per day provides sufficient capacity for the anticipated disposal needs. The barge route runs from ATS to Rambler Channel Typhoon Shelter, with onward transport by truck via Kwai Yue Street, Kwai Tai Road, Kwai Tsing Road, Tsuen Wan Road, New Territories Circular Road, Lung Mun Road, Lung Kwu Tan Road and Nim Wan Road. Alternatively, the truck route runs directly from ATS via Shum Wan Road, Nam Long Shan Road, Wong Chuk Hang Road, Route 1, Route 3, Tuen Mun Road, Lung Mun Road, Lung Kwu Tan Road and Nim Wan Road. With proper on-site handling and storage as well as regular disposal of the waste, no unacceptable environmental impact would be anticipated.  Recommendations of mitigation measures for managing general refuse are presented in Section 6.5.12 - 6.5.14

Dredged Sediments

6.4.16        The Project site is located at Aberdeen Channel. DCM with partial dredging and removal of hard materials will be adopted widely for the construction of the proposed breakwaters (with dredging depth of about 3 m), whereas fully dredging is required for landfalls connecting the proposed breakwaters and the headland.  Marine-based sediment would be generated from the proposed dredging works for the construction of proposed breakwaters.

6.4.17        EPD conducts routine monitoring of the marine sediment quality across the territory of Hong Kong waters.  The nearest EPD’s sediment monitoring stations is monitoring station Hong Kong Island (South) (SS2) located within the Southern Water Control Zone.  The latest available sediment quality data (from 2018 to 2022) are summarised in the Annual Marine Water Quality Report 2022 published by EPD.  Based on the EPD’s annual report, all the contaminants in the samples collected from SS2 were below the LCEL in accordance with ETWB TCW No. 34/2002.  Based on the monitoring data, the samples collected from SS2 were classified as uncontaminated Category L sediment.

6.4.18        In order to characterise the proposed dredged sediment for marine disposal option and pursuant to Clause 3(i) in Appendix E of the EIA Study Brief, a SSTP was prepared with reference to ETWB TCW No. 34/2002 and was agreed by EPD on 23 November 2022, before the updates of PAH were implemented.  The SSTP details the ranges of parameters to be analysed; the number, type and methods of sampling; sample preservation; chemical and biological laboratory test methods to be used.  The agreed SSTP is enclosed in Appendix 6.1.

6.4.19        As proposed in the agreed SSTP under the EIA Study, a 200m x 200m sampling grid arrangement with reference to the memo “Control Measures for Management of Dredged/Excavated Contaminated Sediment” issued by DevB (ref: 0 in DEVB(W) 515/83/04) was adopted.  Based on the adopted sampling grid arrangement, a total of 8 marine-based sediment sampling locations were proposed within the potential area of dredging.  After the agreement on the SSTP was sought, the dredging option was confirmed and the dredging extent was finalised.  A review of validity of SSTP has been conducted and it was confirmed that the proposed sediment sampling locations and corresponding sampling grids fully covered the finalised dredging extent.  As such, the SSTP is considered to remain valid for the Project. The proposed sampling locations, sampling grids and finalised dredging extent are shown in Figure 6.1.

6.4.20        The sediment quality data from the sampling and testing works was reviewed, making reference to ETWB TCW No. 34/2002 and the memo Control Measures for Management of Dredged/Excavated Contaminated Sediment (ref: 0 in DEVB(W) 515/83/04), to identify and characterise the dredged sediment, estimate the quantities of sediment to be encountered in the Project and propose transportation routings and handling/disposal arrangements/methods to fulfil the requirements of the EIA Study Brief.

Sediment Sampling Works

6.4.21        Ground Investigation (GI) works was conducted between January and February 2023 according to the agreed SSTP. The sampling works were conducted by Fugro Geotechnical Services Limited and the laboratory testing was carried out by ALS Technichem (HK) Pty. Ltd., an HOKLAS accredited laboratory.

6.4.22        The sediment sampling locations were conducted taken into consideration the site constraints (e.g. restricted access due to shallow water depth). All as-built sampling locations were still within the corresponding sampling grid and are shown in Figure 6.1.

6.4.23        It should be noted that changes were made to the naming of the sampling location IDs after EPD’s agreement on the SSTP. The original and revised sampling location IDs are shown in Table 6.2 and Figure 6.1.  The revised sampling location IDs will be adopted in this assessment.

Table 6.2    Original and Revised Sampling Location IDs for the Assessment

Original Sampling Location IDs under SSTP

Revised Sampling Location IDs Adopted in this Assessment

ATS-01

MDH5

ATS-03

MDH8*

MDH20*

ATS-04

MDH9

ATS-06

MDH12

ATS-07

MDH14

ATS-08

MDH15

ATS-09

MDH17^

ATS-10

MDH19^

Notes:
* MDH8 and MDH20 represent the same sampling location.

^ Based on the latest engineering design, no sediment dredging works are expected within the sampling grids of MDH17 and MDH19.  As such, the samples taken from the MDH17 and MDH19 were not assessed under this assessment.

6.4.24        The marine-based sediment sampling was carried out by means of grab sampling at the seabed level and borehole drilling method for the vertical sediment profiles below. Undisturbed samples using U100 and piston sampler were collected from seabed surface, 0.9 m down, 1.9 m down, 2.9 m down and thereafter every 3 m down to the borehole termination depth.  The depth of sediment sampling was terminated at least 1 m below the base of sediment.

6.4.25        For MDH8, due to low sample recovery for testing, only surface grab sample was able to be collected and tested.  In order to provide sediment quality data at lower sediment depth, additional undisturbed sediment samples were collected at MDH20, near MDH8 and within the corresponding sampling grid, for laboratory testing.

6.4.26        Based on the latest engineering design, no sediment dredging works are expected within the sampling grids of MDH17 and MDH19 (refer to Figure 6.1).  As such, the samples taken from MDH17 and MDH19 were not assessed under this assessment.

6.4.27        Grab sediment sample was also collected from EPD’s routine sediment monitoring station PS6 at Port Shelter (850234E, 820057N) on 10 February 2023 as the reference sediment sample using closed grab sampler.

Chemical and Biological Screening

6.4.28        As discussed in Section 6.4.16 above, DCM with partial dredging and removal of hard materials will be adopted widely for the construction of the proposed breakwaters (with dredging depth of about 3 m), whereas fully dredging is required for landfalls connecting the proposed breakwaters and the headland.  A total 23 sediment samples from the 7 sampling locations (including sampling location MDH20 but excluding sampling locations MDH17 and MDH19) were collected at / within the vertical dredging extent for laboratory testing. Each sample was tested for chemical screening with parameters as stated in ETWB TCW No. 34/2002. The chemical screening results are summarised in Table 6.3 with details provided in Appendix 6.2. Laboratory analytical reports for chemical screening are provided in Appendix 6.4.

Table 6.3    Summary of Chemical Screening Results 

Category

No. of Samples

Percentage

Category L (equal to or below LCEL)

21

91.30%

Category M (above LCEL but equal to or below UCEL)

2

8.70%

Category H (above UCEL but equal to or below 10x LCEL)

0

0%

Category H (above 10x LCEL)

0

0%

Total:

23

100%

6.4.29        Based on the chemical screening results, Category M sediment was found in 2 samples at sampling locations MDH5.  The remaining samples were identified as Category L sediment.

6.4.30        Based on the chemical screening results and according to ETWB TCW No. 34/2002, Tier III biological screening was conducted on the 2 Category M sediment samples and all the sediment samples passed the screening results.  The results of the biological screening are summarised in Table 6.4 with details provided in Appendix 6.3. The laboratory analytical reports for biological screening are provided in Appendix 6.5.

Table 6.4    Summary of Biological Screening Results

Sampling ID

Sampling

Depth (m bgl)

Classification

Result of Biological Screening

MDH5

Seabed Surface

Category M

Pass

MDH5

1.50 – 1.95

Category M

Pass

Sediment Disposal Options and Quantities

6.4.31        Based on the screening results and the above findings, the disposal options for each of the sediment samples were determined in accordance with the ETWB TCW No. 34/2002. The sediment quantities to be generated under each disposal option were then estimated with consideration of (i) the dredging extent for construction of the proposed breakwaters, (ii) the depths and thicknesses of the underlying sediment based on the sediment sampling works and (iii) the determined disposal options of the sediment samples as based on the chemical and biological screening results. The total volume of sediment generated is estimated to be approximately 241,263 m3.  Beneficial reuse will be considered during the detailed design and construction phase before the disposal of dredged sediment. Based on current estimation, the quantities for each disposal type are presented in Table 6.5. Detailed calculation of excavated sediment quantities and assumptions are presented in Appendix 6.6.

Table 6.5    Estimated Quantities of Sediment under each Disposal Option

Disposal Option

Corresponding Category

Estimated In-situ Quantity (1),(2) (m3)

Type 1 – Open Sea Disposal

Category L Sediment

198,855

Type 1 – Open Sea Disposal (Dedicated Sites) at disposal site(s) allocated by MFC

Category M Sediment (passed the biological screening)

42,408

Type 2 – Confined Marine Disposal at disposal site(s) allocated by MFC

Category H Sediment (does not require biological screening)

0

Type 3 – Special Treatment/ Disposal

Category H Sediment (failed biological screening)

0

Total

241,263

Notes:

(1)     The quantities shown in the table are estimates based on the finalised dredging extent for the construction of the proposed breakwaters. Possibility of reusing dredged sediment will be subject to further review during the detailed design and construction phase.

(2)     The estimated quantities included marine deposit and excluded other materials such as alluvium.

6.4.32        The sediment would be disposed of at the designated marine disposal areas according to ETWB TCW No. 34/2002. The disposal options for the dredged sediment should follow the procedures in ETWB TCW No 34/2002.  It is assumed that a maximum of about 3 barge trips per day will be sufficient to handle these materials to the designated marine disposal areas during construction phase[4].  Subject to agreement with Marine Fill Committee (MFC) of CEDD, the marine disposal sites for Type 1 – Open Sea Disposal and Type 1 – Open Sea Disposal (Dedicated Sites) are typically South Cheung Chau and East of Ninepin.  The potential transportation routing would be via East Lamma Channel, West Lamma Fairway and South Shek Kwu Chau Fairway (for South Cheung Chau) and via East Lamma Channel, south of Hong Kong Island and Tathong Channel (for East of Ninepin).  The actual transportation routing and frequency for marine disposal to designated disposal outlets shall be agreed with EPD/CEDD during the construction phase prior to marine disposal. The recommended mitigation measures for marine disposal are discussed in Section 6.5.15 - 6.5.22. No adverse waste management implications are anticipated if the recommended mitigation measures are implemented.

Operation Phase

6.4.33        The operation of the Project is anticipated to commence in 2030. Wastes arising from the operation of the Project would include floating refuse and general refuse.

6.4.34        Floating refuse tends to accumulate near the coastline as shoreline refuse drifted by wind and tide, especially in summer months following heavy rains and typhoons.  Floating refuse may accumulate in the newly constructed breakwaters and wave wall in the form of floating breakwater.  In addition, general refuse would be generated from vessel users in the ATS during operation phase. According to the Environmental Report 2023 published by MD, the marine refuse (comprising both floating refuse and refuse from local vessels) amounted to 2,404 tonnes in 2023.  The amount covered Hong Kong waters and included the 14 gazetted typhoon shelters in Hong Kong.  As a conservative approach, assuming the gazetted typhoon shelters generated most of the 2,404 tonnes of refuse, the estimated floating refuse and general refuse generated in the ATS expansion area with sheltered space of about 24 hectares (ha) would be approximately 374 kg/day (i.e. (2,404,000 kg / 423 ha x 24 ha) / 365 days)[5].

6.4.35        According to the current practice, any floating marine refuse will be collected by regular operation of MD’s contractor and domestic refuse collection services are provided to local vessels in ATS twice per day by MD’s contractor.  With proper implementation of management control practices, no unacceptable environmental impact (including potential hazard, air and odour emissions, noise, wastewater discharges and wind-blown litters) and public transport impact would thus be anticipated.

6.5                Mitigation of Adverse Environmental Impacts

Waste Management Hierarchy

6.5.1           The waste management hierarchy has been applied in the assessment and development of mitigation measures for waste which aims at evaluating the desirability of waste management methods and includes the followings in descending preference:

·      Avoidance and reduction of waste generation;

·      Reuse of materials;

·      Recovery and recycling of residual materials where possible; and

·      Treatment and disposal according to relevant laws, guidelines and good practices.

6.5.2           Good site practices and waste reduction measures to achieve avoidance and minimisation of waste generation in the hierarchy are recommended as follow.

Good Site Practices

6.5.3           Adverse impacts would not arise in the construction site, provided that good site practices are strictly followed.  Recommendations for good site practices during the construction phase include:

·       Nomination of approved personnel, such as a site manager, to be responsible for implementation of good site practices, arrangements for waste collection and effective disposal to an appropriate facility;

·       Training of site personnel in site cleanliness, concepts of waste reduction, reuse and recycling, proper waste management and chemical waste handling procedures;

·       Provision of sufficient waste reception / disposal points, and regular collection of waste;

·       Adoption of appropriate measures to minimise windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers;

·       Provision of regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors, if any;

·       Adoption of a recording system for the amount of wastes generated, recycled and disposed (including the disposal sites); and

·       Preparation of WMP, as a part of the EMP in accordance with ETWB TC(W) No. 19/2005 "Environmental Management on Construction Sites" for submission to the Architect/Engineer for approval.

Waste Reduction Measures

6.5.4           Good management and control of construction site activities / processes can minimise the generation of waste.  Waste reduction is best achieved at the planning and design stage, as well as by ensuring the implementation of good site practices.  Recommendations to achieve waste reduction are discussed as follow:

·       Segregate and store different types of construction related waste in different containers, skips or stockpiles to enhance reuse or recycling of materials and their proper disposal;

·       Provide separate labelled bins to segregate recyclable waste such as aluminium cans from other general refuse generated by the work force, and to encourage collection by individual collectors;

·       Recycle any unused chemicals or those with remaining functional capacity;

·       Maximise the use of reusable steel formwork to reduce the amount of C&D materials;

·       Adopt proper storage and site practices to minimise the potential for damage to, or contamination of construction materials;

·       Plan the delivery and stock of construction materials carefully to minimise the amount of waste generated;

·       Minimise over ordering and wastage through careful planning during purchasing of construction materials; and

·       Caisson units will be precast off-site and transported to site for installation using semi-submersible barge and supporting tugs.

6.5.5           In addition to the above good site practices and waste reduction measures, specific mitigation measures are recommended below for the identified waste arising to minimise environmental impacts during the handling, transportation and disposal of these waste.

Reducing and Reuse of C&D Materials

6.5.6           Careful design, planning together with good site management can reduce over-ordering and generation of C&D materials such as concrete, mortar and cement grouts.  The following potential measures are identified to maximise reuse/recycling of C&D materials generated from the Project:

·       Formwork should be designed to minimise the use of standard wooden panels, so that high reuse levels can be achieved; 

·       Alternatives such as steel formwork or plastic facing should be considered to increase the potential for reuse; and

·       Where possible, suitable materials such as the rock armour units from the modification of the existing breakwaters are proposed for re-use in the construction of the proposed breakwaters.

6.5.7           To minimise off-site disposal of inert C&D materials, the excavated inert materials with suitable characteristics / size should be reused on-site as fill material.  The surplus inert C&D materials would be transported and delivered to public filing area for beneficial reuse as fill material by other projects.  Prior to disposal of non-inert C&D materials, steel and other metals should also be separated for reuse and / or recycle where practicable so as to minimise the quantity of waste to be disposed of at landfill. 

Delivering of C&D Materials

6.5.8           In order to monitor the delivering of C&D materials at the designated PFRF and landfill and to control fly-tipping, the following measures should be implemented:

·       A trip-ticket system should be included.  One may make reference to DEVB TC(W) No.06/2010 for details; 

·       A recording system for the amount of waste generated, recycled and disposed, including the disposal sites, should be set up;

·       Warning signs should be put up to remind the designated disposal sites;

·       The application of Global Positioning System (GPS) or equivalent systems should be incorporated on all dump trucks for real-time tracking and monitoring;

·       Closed-circuit television (CCTV) should be installed at the vehicular entrance and exit of the site as additional measures to prevent fly-tipping; and

·       When delivering inert C&D materials at a PFRF for beneficial reuse, the material shall only consist of soil, rock, concrete, brick, cement plaster / mortar, inert building debris, aggregates and asphalt, and be free from marine mud, household refuse, plastic, metals, industrial and chemical waste, animal and vegetable matter, and other material considered to be unsuitable by the Filling Supervisor.

Chemical Waste

6.5.9           Mitigation measures for chemical waste are as follow:

·       If chemical waste is produced at the construction site, the Contractor would be required to register with the EPD as a Chemical Waste Producer and must follow the guidelines stated in the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes; 

·       Good quality containers compatible with the chemical wastes should be used, and incompatible chemicals should be stored separately; 

·       Appropriate labels should be securely attached on each chemical waste container indicating the corresponding chemical characteristics of the chemical waste, such as explosives, flammable, oxidising, irritant, toxic, harmful, corrosive, etc; and

·       The Contractor shall use a licensed collector to transport and dispose of the chemical wastes at a licensed chemical waste treatment and disposal facility such as CWTC at Tsing Yi in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

Floating Refuse

6.5.10        Apart from collecting and storing waste with good waste management practice on site to avoid having waste transported to sea under extreme weather conditions, Contractor for marine works should be responsible for the collection of refuse, if any, within the works area.  Contractor shall collect and remove floating refuse at regular intervals on a daily basis to keep water within the site boundary and the neighbouring water free from rubbish during the construction phase. 

6.5.11        In case of floating refuse is identified, a waste collection vessel is needed to remove the floating materials and eventually store and dispose of together with the general refuse, after separating the recyclables for recycling.

General Refuse

6.5.12        General refuse should be stored in enclosed bins or compaction units separate from C&D materials and chemical wastes.  A reputable waste collector should be employed by the Contractor to remove general refuse from the site, separately from C&D materials and chemical wastes, on a daily basis to minimise odour, pest and litter impacts.  The collected general refuse will be disposed of at designated landfill. 

6.5.13        Clearly labelled recycling bins should be provided on site in order to encourage segregation and recycling of aluminium and plastic wastes, and wastepaper in order to reduce general refuse production. 

6.5.14        The Contractor should carry out an education programme for workers in avoiding, reducing, reusing and recycling of materials generation.  Posters and leaflets advising on the use of the bins should also be provided onsite as reminders.  The recyclable waste materials should then be collected by reliable waste recycling agents on a regular (e.g. daily) basis.

Dredged Sediments

6.5.15        The sediment should be dredged, handled, transported and disposed of in a manner that would minimise adverse environmental impacts. Beneficial reuse will be considered during the detailed design and construction phase before the disposal of dredged sediment.

6.5.16        Requirements of the Air Pollution Control (Construction Dust) Regulation, where relevant, shall be adhered to during dredging, transportation and disposal of the sediment.

6.5.17        For off-site disposal, the basic requirements and procedures specified under prevailing guidelines/circulars shall be followed. MFC of CEDD is managing the disposal facilities in Hong Kong for the dredged sediment, while EPD is the authority of issuing marine dumping permit under the DASO.

6.5.18        For the purpose of site allocation and application of marine dumping permit and if considered necessary by EPD (Marine Dumping Control Section / Territorial Control Office), separate SSTP(s) shall be submitted to EPD for agreement under DASO.  Additional GI works, based on the SSTP(s), shall then be carried out in order to confirm the disposal arrangements of the dredged sediment.  Sediment Quality Report(s) (SQR), reporting the chemical and biological screening results and the estimated quantities of sediment under different disposal options, shall then be submitted to EPD for agreement under DASO.

6.5.19        To ensure disposal space is allocated for the Project, the Project Proponent should be responsible for obtaining agreement from MFC on the rationale for sediment removal and the allocation of the disposal site. The contractor(s), on the other hand, should be responsible for the application of the marine dumping permit under DASO from EPD for the sediment disposal.

6.5.20        The dredged sediments are expected to be loaded onto the barge and transported to the designated disposal sites allocated by MFC.  The dredged sediment would be disposed of according to its determined disposal options and prevailing guidelines/circulars.

6.5.21        In order to minimise the potential odour / dust emissions during dredging and transportation of the sediment, the dredged sediments shall be wetted during dredging / material handling and shall be properly covered when placed on barges.  Loading of the dredged sediment to the barge shall be controlled to avoid splashing and overflowing of the sediment slurry to the surrounding water.

6.5.22        The barge transporting the sediments to the designated disposal sites shall be equipped with tight fitting seals to prevent leakage and shall not be filled to a level that would cause overflow of materials or laden water during loading or transportation.  In addition, monitoring of the barge loading shall be conducted to ensure that loss of material does not take place during transportation.  Transport barges or vessels shall be equipped with automatic self-monitoring devices.

6.5.23        A summary of the various types of waste to be generated during construction and operation phases of the Project, together with the recommended handling methods and disposal routes are presented in Table 6.6.

Table 6.6    Summary of Estimated Waste Arising and Recommended Disposal

Waste Material Type

Generated From

Materials to be Generated

Total Quantity Generated (Approx.)

Handling Methods

Disposal Outlets

Construction Phase (2026 – 2030)

C&D Materials

General construction works and shortening of existing breakwater

Inert C&D materials

24,000 m3

 

•     Segregation from non-inert C&D materials

•     Reuse on-site as backfill materials

•     Tuen Mun Area 38 Fill Bank for beneficial reuse in other projects

 

Non-inert C&D materials

1,000 m3

 

•    Segregation from inert C&D materials 

•    Reusable materials should be separated and recycled

•     WENT Landfill

 

Chemical Waste

Plant equipment, machinery maintenance and servicing

Oil / grease, cleaning fluids, solvents, lubrication oil and fuel, used oil filter and scrap batteries etc.

A few cubic metres per month

•    Store in compatible containers in designated area on site

•    To be collected and/or recycled by a licensed collector

•     Recycled by licensed facility and/or disposal of at the CWTC

Floating Refuse

Accumulation along proposed breakwaters and wave wall in the form of floating breakwater

Food scraps, plastics, waste paper and empty containers etc.

Maximum 4.4 m3 per year

•    Collected by Contractor of this Project if within works area and be handled as general refuse

•     If collected by Contractor of this Project if within works area, to be disposed of as general refuse

General Refuse

Resident site staff and workers

Food waste, plastic bottles, aluminium cans, waste papers, etc.

Maximum 260 kg/day

•    Reuse or recycle before disposal of at landfill

•    Provide on-site collection points together with recycling bins

•    To be collected by an appropriate waste collector to be employed by the Contractor

•     WENT Landfill

 

Dredged Sediments

Construction of proposed breakwaters

Category L Sediment

198,855 m3

 

•    Beneficial reuse will be considered during the detailed design and construction phase before the disposal of dredged sediment.

•    For marine disposal, final disposal site shall be determined by MFC; typically South Cheung Chau / East of Ninepin

•     Surplus materials would be disposed of as Type 1 - Open sea disposal at marine disposal site(s) allocated by MFC

 

Category M Sediment (passed Tier III biological screening)

42,408 m3

 

•    Final disposal site shall be determined by MFC; typically South Cheung Chau / East of Ninepin

 

 

 

•     Type 1 - Open sea disposal (dedicated site) at marine disposal site(s) allocated by MFC

Operation Phase (2030 onwards)

Floating Refuse

Accumulation along proposed breakwaters and wave wall in the form of floating breakwater

Food scraps, plastics, waste paper and empty containers etc.

Maximum 374 kg/day (including both floating refuse and general refuse)

•    Existing regular operation of MD’s contractor to collect floating refuse in the vicinity

•     Same as the existing practice, collected by appointed contractor of MD.

General Refuse

Vessel users

Food waste, plastic bottles, aluminium cans, waste papers, etc.

Refer to Floating Refuse (Operation phase) above.

•    Existing regular operation of MD’s domestic refuse collection services to collect general refuse from local vessels.

•     WENT Landfill

6.6                Evaluation of Residual Impacts

6.6.1           With the implementation of the recommended mitigation measures for the handling, transportation and disposal of the identified waste arising, residual impacts would not be expected during the construction and operation of the Project.

6.7                Environmental Monitoring and Audit Requirements

Construction Phase

6.7.1           It would be the contractor’s responsibility to ensure that any wastes produced during the construction and demolition works are handled, stored and disposed of in accordance with good waste management practices and relevant regulations and other legislative requirements. The recommended mitigation measures should form the basis of the site WMP to be developed by the Contractor in the construction phase.

6.7.2           It is recommended that the waste arisings generated during the construction activities should be audited regularly at least once per week by the Environmental Team (ET) to determine if wastes are being managed in accordance with approved procedures. The audits should look at all aspects of on-site waste management practices including waste generation, storage, recycling, transport and disposal. Apart from site inspections, documents including licenses, permits, disposal and recycling records should be reviewed and audited for compliance with the legislation of the recommended good site practice and other waste management mitigation measures.

6.7.3           A WMP, as a part of the EMP, should be prepared in accordance with ETWB TCW No.19/2005 and submitted to the Engineer for approval. The recommended mitigation measures should form the basis of the WMP. The monitoring and auditing requirement stated in ETWB TCW No.19/2005 should be followed with regard to the management of C&D materials.

Operation Phase

6.7.4           No environmental monitoring and audit (EM&A) requirement is considered necessary during the operation phase.

6.8                Conclusion

Construction Phase

6.8.1           Waste management implications associated with the construction and operation of the Project were identified and assessed. During the construction phase, waste types generated by the construction activities of the Project would include C&D materials from general construction works and shortening of existing breakwater, dredged sediments from dredging works, general refuse from workforce and chemical waste from maintenance of construction plant and equipment. Floating refuse may also be trapped and accumulated along the shoreline and breakwaters. Provided that these wastes are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts during the construction phase would not be anticipated.

6.8.2           The total volume of dredged sediment generated from the Project is estimated to be approximately 241,263 m3. Based on the results of the chemical and biological screening, approximately 198,855 m3 of sediment is suitable for Type 1 – Open Sea Disposal and 42,408 m3 of sediment is suitable for Type 1 – Open Sea Disposal (Dedicated Sites) in accordance with ETWB TCW No. 34/2002.  With the implementation of the recommended mitigation measures and in accordance with the requirements of prevailing guidelines/circulars, no adverse environment impacts would be expected from dredging, transportation and disposal of marine sediment.

Operation Phase

6.8.3           During the operation phase, the key waste types generated will include general refuse from vessel users in the ATS. There would also be accumulation of floating refuse on the newly constructed wave wall in the form of floating breakwater and breakwaters of the Project. Provided that all these wastes are handled, transported and disposed of in strict accordance with the relevant legislative requirements and the recommended mitigation measures are properly implemented, no adverse environmental impact is expected during the operation phase.



[1] Assuming 2 work fronts with 1 barge at each work front per day, the loading capacity of each barge is about 2,000 m3 with bulk factor of 1.3 and works are 48 weeks a year and 6 days a week.

[2] Assuming the loading capacity of each barge and dump truck are 2,000 m3 and 6 m3 respectively.

[3] Assuming bulk density of 311.73kg/m3 and works are 48 weeks a year and 6 days a week.

[4] Assuming maximum 3 work fronts per day for the proposed dredging operation with 1 barge at each work front, each barge with a loading capacity of about 2,000 m3 and works are 48 weeks a year and 6 days a week.

[5] According to Annex I of LC Paper No. CB(4)691/2023(01) – Legislative Council Subcommittee to Study Matters Relating to Typhoon Shelters and Sheltered Anchorages (14 July 2023), the 14 gazetted typhoon shelters provide 423 hectares of berthing space for vessels.