TABLE OF CONTENTS

 

 

7       waste management implications.. 7-1

7.1       Introduction. 7-1

7.2       Environmental Legislation, Standards and Guidelines. 7-1

7.3       Description of Environment 7-4

7.4       Identification and Evaluation of Wastes Implications. 7-4

7.5       Mitigation of Adverse Environmental Impacts. 7-12

7.6       Evaluation of Residual Environmental Impacts. 7-18

7.7       Environmental Monitoring and Audit Requirement 7-18

7.8       Conclusion. 7-18

 

LISTS OF FIGURE

NEX1062/S/SHD/ACM/Z10/190

As-built Sediment Sampling Locations for SHD

 

LIST OF appendiCES

Appendix 7.1         PNAP No. 252 (ADV-21) Management Framework for Disposal of Dredged/Excavated Sediment

Appendix 7.2         Memo on Control Measures for Management of Dredged/Excavated Contaminated Sediment

Appendix 7.3         Summary of Chemical Screening Results and Disposal Options

Appendix 7.4         Summary of Biological Screening Results

Appendix 7.5         Laboratory Analytical Report (Chemical Screening)

Appendix 7.6         Laboratory Analytical Report (Biological Screening)

 



7                  waste management implications

7.1              Introduction

7.1.1          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 the wastes.

7.1.2          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.  Handling and disposal of sediments are also discussed in this section.

7.2              Environmental Legislation, Standards and Guidelines

7.2.1          The criteria and guidelines for assessing waste management implications are outlined in Annex 7 and 15, respectively, of the Technical Memorandum on Environmental Impact Assessment Process (TM-EIAO).

7.2.2          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.132BK) 每 Public Cleansing and Prevention of Nuisances Regulation;

        Dumping at Sea Ordinance (Cap. 466); and

        Buildings Ordinance (Cap 123).

 

Waste Disposal Ordinance (Cap. 354)

7.2.3          The Waste Disposal Ordinance (WDO) 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 can be disposed of only at designated waste disposal facilities licensed by the Environmental Protection Department (EPD).

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

7.2.4          Issued under the WDO, the Chemical Waste (General) Regulation administers the possession, storage, collection, transport and disposal of chemical wastes.  EPD has also issued three &guideline* documents, namely A Guide to the Chemical Waste Control Scheme (2016), A Guide to the Registration of Chemical Waste Producers (2016) and Code of Practice on the Packaging, Labelling and Storage of chemical Wastes (1992), which detail how the Contractor should comply with the regulations on chemical wastes.

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

7.2.5          Under the Waste Disposal (Charges for Disposal of Construction Waste) Regulation enacted in January 2006, 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 (Cap. 28)

7.2.6          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 public fill reception facilities are required to obtain Dumping Licences. The licences are issued by CEDD under delegated authority from the Director of Lands.

7.2.7          Individual licences and windscreen stickers are issued for each vehicle involved.  Under the licence conditions, public fill reception facilities 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 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 每 Public Cleansing and Prevention of Nuisances Regulation (Cap.132BK)

7.2.8          The Public Cleansing and Prevention of Nuisances Regulation provides control on illegal dumping of wastes on unauthorised (unlicensed) sites. The illegal dumping of wastes can lead to a fine and/or imprisonment.

Dumping at Sea Ordinance (Cap.466)

7.2.9          This Ordinance 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.

7.2.10       Marine disposal of any dredged/excavated sediment is subject to control under the Dumping at Sea Ordinance.  Dredged/excavated sediment destined for marine disposal is classified based on its contaminant levels with reference to the Practice Notes for Authorized Persons, Registered Structural Engineers and Registered Geotechnical Engineers No. 252 ADV-21 (PNAP No. 252 (ADV-21) - Management Framework for Disposal of Dredged/Excavated Sediment (PNAP No. 252 (ADV-21)).  The PNAP No. 252 (ADV-21) stipulated a set of sediment quality criteria or Chemical Exceedance Levels (CEL) for contaminants including metals, metalloid and organic pollutants.  

Buildings Ordinance (Cap.123)

7.2.11       Private projects are regulated by the Buildings Ordinance and relevant Practice Notes for Authorised Persons, Registered Structural Engineers and Registered Geotechnical Engineers (PNAPs). The PNAP No. 243 (ADV-19) Construction and Demolition Waste has introduced waste prevention measures to enhance the management of C&D materials which include:

        Identifying opportunities to prevent waste during project planning and design stage and construction stage; and

        Requiring the contractor to prepare a Waste Management Plan (WMP) including areas described in PNAP No. 243 (ADV-19) and submit to the project proponent for agreement.

 

Environmental Guidelines

7.2.12       Environmental guidelines that are related to wastes management and disposal include:

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

        Works Branch Technical Circular No. 2/93B, Public Filling Facilities;

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

        PNAP No. 252 (ADV-21) 每 Management Framework for Disposal of Dredged/Excavated Sediment;

        PNAP No. 243 (ADV-19) 每 Construction and Demolition Waste; and

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

 

7.2.13       The current policy related to the disposal of C&D materials is documented in the WBTC No. 2/93, &Public Dumps*. C&D materials that are wholly inert, namely public fill, should not be disposed of at landfill, but be taken to PFRFs, which usually form part of reclamation schemes. 

7.2.14       In accordance with the DevB TC(W) No. 6/2010 &Trip Ticket System for Disposal of Construction and Demolition Materials*, 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 Public Fill Committee (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 equal or exceed 50m3, 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 50m3, 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.

7.2.15       Further measures have been introduced under Paragraph 4.1.3 of Chapter 4 of the PAH for Civil Engineering Works to enhance the management of C&D materials including rock, and to minimize 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 minimize C&D materials generation and to encourage proper management of such materials;

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

7.2.16       Measures have been introduced in PNAP No. 243 (ADV-19) to enhance the management of C&D materials and to minimize its generation at source.  The enhancement measures include the identification of opportunities to prevent waste during both the project planning and design stage as well as construction stage, and preparation of a Waste Management Plan (WMP) to ensure that measures are implemented during the construction stage for reduction of C&D materials.

7.2.17       The PNAP No. 252 (ADV-21) sets out the procedure for seeking approval to and the management framework for marine disposal of dredged/ excavated sediment.  This Practice Note outlines 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 A of PNAP No. 252 (ADV-21). 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 PNAP No. 252 (ADV-21):

        Type 1 每 Open Sea Disposal or Open Sea Disposal in Dedicated Sites;

        Type 2 每 Confined Marine Disposal; and

        Type 3 每 Special Treatment / Disposal.  For Type 3 disposal, the Authorized Persons / Registered Structural Engineers shall be responsible for identifying and agreeing with the DEP the most appropriate treatment and/or disposal arrangement. 

7.3              Description of Environment

7.3.1          The existing SHD, with an area of about 30 hectares, is sited on reclaimed land in Northshore Lantau and has operated since 1998 for supporting the operation of the existing TCL, AEL and DRL.  The existing SHD comprises stabling sidings and main depot building located in the centre of the site, permanent way facilities at the north eastern side, test track at the southern area, and other supporting facilities including maintenance workshops, utilities and drainage, ancillary buildings and facilities, traction substation and sewage pumping station, etc.

7.3.2          Municipal solid waste (MSW) including solid waste from commercial and industrial sources will be generated during the operation of SHD. The MSW would be stored on site for further recycling or disposal, whereas the chemical wastes would be temporarily stored in designated area and collected by licensed chemical waste collector according to the requirements under CAP 354C.  For general refuse, a waste collector is arranged to collect the general refuse from the SHD.

7.4              Identification and Evaluation of Wastes Implications

Assessment Methodology

7.4.1          The criteria and methodology of assessing potential waste management implications during the construction and operation phases follows Annexes 7 and 15 of the TM-EIAO respectively, with assessment approaches provided below:

        Estimation of the types and quantities of the wastes generated;

        Evaluation of opportunities for waste reduction and re-use;

        Identification of disposal options for each type of wastes;

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

        Assessment of impacts on the capacity of waste collection, transfer and disposal facilities.

Construction Phase

7.4.2          The construction activities to be carried out for the Project would be generate a variety of wastes that can be divided into distinct categories based on their composition and ultimate method of disposal. The identified wastes types are:

        Construction and demolition (C&D) materials;

        General refuse;

        Chemical wastes; and

        Land-based sediments.

Construction and Demolition Materials

7.4.3          C&D materials would be generated from excavation, demolition works, site formation, construction of facilities and station. These C&D materials comprise both inert (e.g. rocks, soil, broken concrete, building debris) and non-inert components (e.g. vegetation and wood).

7.4.4          In view of site constraints, scale and nature of the Project, the available schemes for construction of SHO are limited, generation of C&D materials has been minimized as far as possible with the following measures taken in consideration:

        Constant design reviews in striving to optimise the scheme proposals;

        Minimal interference with existing structures to reduce the quantity of demolition materials;

        Proposed use of prefabricated materials where possible; and

        Reuse of existing structures in the design where possible.

7.4.5          Based on preliminary design information, it was estimated that the total volume of C&D materials to be approximately 1,319,370 m3 of inert materials (i.e. public fill) and approximately 18,200m3 of non-inert materials (i.e. C&D waste).   A C&DMMP will be prepared and submitted to the PFC for endorsement in accordance with Chapter 4 of the PAH.

7.4.6          A summary of inert and non-inert C&D materials generated during construction phase is shown in Table 7.1.  Due to limited space of Project site, it may not be practicable to provide a major stockpile area of inert C&D materials for subsequent backfilling or reuse on site.  Nevertheless, there may be small stockpile area(s) provided on-site for temporary storage before delivery to disposal outlets.  Inert C&D materials would be reused on-site as far as practicable subject to the review of detailed design stage before exported off-site for reuse at other concurrent projects. 

Table 7.1     Summary of Inert and non-inert C&D Materials Quantities Generated

Works  

Construction Period

Approx. Quantities of Waste To be Generated (m3)

Excavated Soil(1)

Rock(2)

Artificial Hard Material(3)

Non-inert C&D material(4)

SHO

2019 每 2024(5)

31,450

400

6,910

3,000

SHD Stage 1^

2019-2024

269,000

8,000

57,200

8,000

SHD Stage 2

2024-2028

238,000

8,600

46,760

3,000

SHD Stage 3

2028-2032

262,000

11,000

50,250

2,000

SHD Stage 4

2032-2034

238,000

8,600

80,000

2,000

Local Access

2019-2025

2,560

40

600

200

Total Generation

1,041,010

36,640

241,720

18,200

Disposal Outlet

Public Fill Reception Facilities areas or reclamation sites

Public Fill Reception Facilities areas or reclamation sites

Public Fill Reception Facilities areas or reclamation sites

Designated Landfill Site to be agreed with EPD/CEDD

Notes:

^      The construction of rising mains is included in Stage 1 SHD Replanning Works.

(1)    Excavated soil generated from SHD/SHO site formation works or bored piling works, pile cap construction and excavation works related to the construction of SHD Topside Development.

(2)    ※Rock§ includes all grade rock generated from bored piling works, pile cap construction and excavation works related to the construction of SHD Topside Development.

(3)    ※Artificial hard material§ includes, but not limited to, broken concrete, asphalt, bitumen and granular materials, etc.

(4)    ※Non-inert C&D material§ includes, but not limited to, bamboo, timber, paper and plastic, etc.

(5)    Construction works for SHO will be completed in end 2024 but the operation of SHO would commence in the same time with the population intake in Phase 1 of SHD Topside Development in 2026.

7.4.7          Non-inert C&D materials generated would be reused and recycled as much as possible before disposal of at designated landfill site to be agreed with EPD/CEDD. 

7.4.8          The number of construction vehicle involved in transporting C&D materials/land-based sediment to the disposal outlets is estimated to be less than 40 nos. per hour, 7am to 7pm, throughout the construction phase, based on the current engineering design.  Upon leaving the construction site, construction vehicles for transporting C&D materials will enter the North Lantau Highway (NLH) westbound, turn around at Tung Chung Interchange and via Tuen Mun-Chek Lap Kok (TM-CLK) Link to Tuen Mun area and ultimately to the designated disposal outlets (Table 7.1 refers) as agreed with EPD/CEDD during construction phase.  It is anticipated that construction vehicles would not enter the existing Tung Chung New Town and the planned extension (i.e. Route 1 in Appendix 3.10).   For the construction vehicles with the excavated sediments, it is expected that the sediment will be loaded from construction vehicles onto the barge at public barging point of which the exact location will be determined by the contractor(s) and agreed by EPD/CEDD and transported to the designated disposal sites allocated by MFC.  As the construction works would be conducted in stages, it is expected that the potential environmental impacts arising from the handling and disposal of the inert C&D materials, such as air and odour emissions, noise and potential hazard, could be minimized with the implementation of appropriate measures as detailed in Section 7.5.

General Refuse

7.4.9          During the construction period, the workforce would generate refuse comprising food scraps, waste paper, empty containers, etc.  Accidental or intentional release of these refuse to the surrounding environment is not permitted and may cause negative environmental impacts.  Storage of general refuse on-site will generate adverse environmental impacts like water contamination, odour nuisance and visual impact if they are not managed in a proper manner.  The site may also attract vermin and pests if the waste containers are not cleaned or maintained properly and frequently.

7.4.10       The maximum number of construction workers to be employed on the Project is estimated to be upto 350 workers in each stage.  Based on a generation rate of 0.65 kg per worker per day, approximately 228 kg of general refuse will be generated daily during the construction period.

7.4.11       The refuse should be stored in enclosed bin to avoid adverse impacts to the surroundings. Recycling bins should be provided to maximize reuse and recycle volume.  A reputable waste collector should be employed to collect the general refuse for later disposal of at landfills.

7.4.12       With proper implementation of waste management practices as detailed in Section 7.5, it is anticipated that the secondary environmental impacts from collection and handling of general refuse would be minimal.

Chemical Waste

7.4.13       The maintenance and servicing of construction plant and equipment may possibly generate a variety of chemical wastes, for instance, cleaning fluids, solvents, lubrication oil and waste fuel. 

7.4.14       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.  The potential hazards include:

        Toxic effects on the workforce;

        Adverse impacts on water quality and aquatic biota from spills; and

        Fire hazards.

7.4.15       Chemical waste producers are required to apply for registration as specified in the Guide to the Registration of Chemical Waste Producers. Materials classified as chemical wastes will be handled and stored on-site according to the requirements specified in Code of Practice on Packaging, Labelling and Storage of Chemical Wastes before collection by licensed collectors and disposal of at the Chemical Waste Treatment Centre (CWTC) at Tsing Yi or other licensed facilities.  Wherever possible, opportunities will be taken to reuse and recycle materials.  It is difficult to quantify the amount of chemical waste that would arise from the construction activities since it would depend on the Contractor*s on-site maintenance requirements and the amount of plant utilised.  However, it is anticipated that the quantity of chemical waste, such as lubricating oil and solvent produced from plant maintenance, would be small to in the order of a few hundred litres per month.   Mitigation and control requirements for chemical wastes are detailed in Section 7.5 Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements, adverse environmental impacts are not expected.

Sediments

7.4.16       The construction activities to be carried out for the Project that would generate land-based sediment are the piling works and excavation works for the proposed SHO, Stage 1 to 4 SHD Replanning Works and local access located to the west of Reprovisioned SHD. The locations of the proposed SHO, Stage 1 to 4 SHD Replanning Works and proposed piling works of local access are shown in Figure No. NEX1062/S/SHD/ACM/Z10/190.

Review of Existing Sediment Quality Data  

7.4.17       During the preliminary design stage, site investigation (SI) was conducted between April and June 2016 to review the geological characteristic within SHO and SHD Replanning Works area.  As there was no sediment quality data available within the excavation area where sediment is expected to be encountered, considering the limitation of availability area for site investigation within an operating depot and minimisation of impact on existing operation, sediment sampling and testing was also conducted concurrently with the site investigation works, according to the PNAP No. 252 (ADV-21) Management Framework for Disposal of Dredged/Excavated Sediment ) (Appendix 7.1 refers).  No dredging works will be required for the Project, and thus no marine-based sediment will be generated.

7.4.18       The timetable for the sediment sampling, chemical / biological screening and the subsequent laboratory reporting is summarised in Table 7.2 below.

Table 7.2     Timetable for Sediment Sampling and Laboratory Testing

Task Descriptions

Time Period

Sediment sampling

April to June 2016

Tier II chemical screening

April to July 2016

Tier III biological screening

May to August 2016

Reporting

August to Sept 2016

 

7.4.19       Upon completion of the SI works, a review on the sediment quality of the sediment sampling and testing works were conducted, making reference to PNAP No. 252 (ADV-21) and memo issued by Development Bureau ※Control Measures for Management of Dredged/Excavated Contaminated Sediment§ (ref: 0 in DEVB(W) 515/83/04) (Appendix 7.2 refers), to identify and characterize the excavated sediment, estimate the quantity of sediment to be encountered in the Project and propose transportation routings and handling/disposal arrangements/methods to fulfill the requirements of ESB-296/2016.

7.4.20       The sediment sampling and testing works commenced on 29th April 2016 which is within 3 years at the time of this EIA Study.  In addition to ground condition remains unchanged, based on PNAP No. 252 (ADV-21) (para. 2), the sampling and testing results obtained within the boundary of SHD (Section 7.4.26 to 7.4.29 refers) are therefore considered to be reliable and representable to the underlying sediment condition for the assessment of waste management implications associated with the sediment excavation under this EIA Study. Details of the review on the sediment quality are discussed below.

Sediment Sampling Locations, Depth of Sampling and Sampling Procedure

7.4.21       The nearest EPD*s sediment monitoring station is NS2 located within the North Western Water Control Zone. The latest available sediment quality data from 2011 to 2015 are summarized in the Annual Marine Water Quality Report 2015 published by EPD. Based on the EPD*s annual report, the measured concentrations of the parameters as listed in PNAP No. 252 (ADV-21) were below the corresponding Lower Chemical Exceedance Level (LCEL).

7.4.22       As it is possible that the sediment contamination level within the study area is Category M/H, a 200m x 200m sampling grid arrangement was adopted to enable a more accurate estimation of mud disposal volume, with reference to the memo issued by Development Bureau, ※Control Measures for Management of Dredged/Excavated Contaminated Sediment§ (ref: 0 in DEVB(W) 515/83/04).

7.4.23       Based on the adopted sampling grid arrangement, sediment sampling were conducted at 15 land-based locations to cover the proposed works areas where sediment could potentially be encountered, i.e. the existing SHD, the proposed SHO station and the proposed piling works for local access as shown in Figure No. NEX1062/S/SHD/ACM/Z10/190. For the remaining areas within the Scheme Boundary, either no excavation works or only shallow excavation above the sediment layer and no excavation of sediment is anticipated. The sediment sampling locations were conducted taken into consideration the site constraints within the Scheme Boundary (e.g. presence of existing structures / facilities / railway and impact to current operation of SHD, TCL and AEL).  

7.4.24       The land-based sediment samples collections were conducted by means of dry rotary drilling method (i.e. without the use of flushing medium). In some occasions, only potable water from nearby fire hydrant via water adaptors supplied by the Water Supplies Department (WSD) was used as drilling fluid when encountering of hard substrata or in difficult cases prior to the encounter of sediment layer, no flushing medium was used during the collection of sediment samples. Inspection pits in the size of 0.3x0.3m were excavated down by hand tools to 3m below ground level (m bgl) to inspect for underground utilities. Drill rigs were then deployed to carry out the drilling and sampling.  Sediment was collected at depths where marine deposits are firstly encountered and samples were generally taken at that particular depth (i.e. immediately above the top of marine deposit), 0.9m down, 1.9m down, 2.9m down and then every 3m down to the borehole termination depth. The depth of sediment sampling was terminated at least 1m below the base of sediment. The as-built sampling locations are shown in Figure No. NEX1062/S/SHD/ACM/Z10/190.

7.4.25       Grab sediment sample was collected from EPD*s routine sediment monitoring station PS6 at Port Shelter (850234E, 820057N) on 22 June 2016 as the reference sediment sample. The grab sediment sample was collected by closed grab sampler and was placed into new/pre-cleaned high density polyethylene containers and wide mouth borosilicate glass bottles with Teflon lined lids and sealed to prevent leakage.

Sediment Sampling and Testing Results

7.4.26       Chemical and biological screening of sediment samples were carried out and each sample was tested for chemical screening according to PNAP No. 252 (ADV-21).

7.4.27       A total of 53 samples were collected from the land-based sampling locations and tested for chemical screening. The chemical screening results are summarised in Table 7.3 with details provided in Appendix 7.3.  The laboratory analytical reports for chemical screening are provided in Appendix 7.5.

7.4.28       Based on the chemical screening results, Category H sediments were identified in 2 samples at locations EDH14 and EDH15 with Zinc exceeded the UCEL but below 10 times the LCEL.  Category M sediments were also found in 5 samples at sampling locations EDH04, EDH16 and EDH17 with Arsenic and/or Zinc exceeded the LCEL but equal to or below the UCEL. The remaining samples were identified as Category L sediment.

Table 7.3     Summary of Chemical Screening Results 

Category

Percentage

No. of Samples

Category L (equal to or below LCEL)

86.8%

46

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

9.4%

5

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

3.8%

2

Category H (above 10x LCEL)

0%

0

Total:

100%

53

 

7.4.29       Based on the chemical screening results, Tier III biological screening was conducted on the 5 Category M sediment samples and all the samples passed the screening. The results of the biological screening are summarised in Table 7.4 with details provided in Appendix 7.4.  The laboratory analytical reports for biological screening are provided in Appendix 7.6.

Table 7.4     Summary of Biological Screening Results

Sampling ID

Sampling Depth (m)

Classification

Result of Biological Screening

EDH04

10.00-10.95

Category M

Pass

16.00-16.95

Category M

Pass

EDH16

12.00-12.95

Category M

Pass

17.00-17.95

Category M

Pass

EDH17

14.50-15.45

Category M

Pass

 

Sediment Disposal Options and Quantities

7.4.30       Based on the screening results and the above findings, the disposal options for each of the sediment samples were determined in accordance with the PNAP No. 252 (ADV-21). The quantities of sediments to be generated under each disposal option is then estimated with consideration of (i) the excavation extent and profiles for the proposed SHO, Stage 1 to 4 SHD Replanning Works and the proposed piling works for local access, (ii) the depths and thickness of the underlying sediment 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 21,826 m3. Beneficial reuse will be considered on site as far as practicable during the construction stage before the disposal of excavated sediment.  Based on current estimation, the quantities for each disposal type are presented in Table 7.5.

7.4.31       It should be noted that no sediment samples were encountered in the sampling location EDH09. It is assumed that no sediment would be encountered within the concerned sampling grid in the quantities estimation.

Table 7.5     Estimated Quantities of Sediment under each Disposal Option

Disposal Option

Corresponding Category

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

Stage 1 & SHO

Stage 2

Stage 3

Stage 4

Type 1 每 Open Sea Disposal

Category L Sediment

8,018

3,909

2,149

4,688

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

Category M Sediment (passed the biological screening)

493

879

166

660

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

Category H Sediment (does not require biological screening)

263

0

51

550

Type 3 每 Special Treatment/ Disposal

Category H Sediment (failed biological screening)

0

0

0

0

Sub-Total

8,774

4,788

2,366

5,898

Total

21,826

Notes:

(1) The quantities shown in the table are estimates only based on the foundation works for current scheme of SHD Topside Development and the possibility of reusing excavated sediment will be subject to further review during the detailed design and construction stages.

(2) The estimated quantities shown in the table include sediment to be generated from the proposed SHO, Stage
1 to 4 of the SHD Replanning Works and the proposed piling works for local access.

7.4.32       The sediment would be disposed of at the designated marine disposal areas according to PNAP No. 252 (ADV-21).  The disposal options for the excavated sediment should follow the procedures in PNAP No. 252 (ADV-21). The transportation routing and frequency for marine disposal to designated disposal outlets (Table 7.6 refers) shall be agreed with EPD/CEDD during the construction phase of each stage prior to marine disposal. The recommended mitigation measures for marine disposal are discussed in Section 7.5. No adverse waste management implications are anticipated if the recommended mitigation measures are implemented.

Operation Phase

7.4.33       During operation of the Project, the major types of wastes generated include:

        Chemical waste; and

        Municipal solid waste.

Chemical Waste

7.4.34       Chemical wastes such as paints, lubricants and used batteries may be generated during maintenance activities in station and depot.  This waste may pose environmental, health and safety hazards.  Measures as stipulated in the Waste Disposal (Chemical Waste) (general) Regulation and the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes would be strictly followed for the handling and disposal of chemical waste.

7.4.35       Should any chemical waste be generated, the operator must register with EPD as a chemical waste producer.  The chemical waste would be readily accepted for disposal of at the CWTC at Tsing Yi or other licensed facilities.  This chemical waste should be collected periodically in drum-type containers by licensed chemical waste collectors.  With proper storage, handling and disposal of this waste, no adverse environmental impact is anticipated.

Municipal Solid Waste (MSW)

7.4.36       During the operation phase, MSW such as food waste, paper, plastic and office waste would be generated by staff and commercial operators, and scrap materials from rail and carriage maintenance, used fluorescent tubes, used welding rods, cleansing materials and discarded electronic equipment from maintenance activities of the station and tracks.  

7.4.37       The maximum number of persons including staff and commercial operators in SHO and Reprovisioned SHD during the operation phase of the Project is estimated to be about 200.  Based on a generation rate of 0.65 kg per person per day, approximately 130kg of MSW (general refuse) will be generated daily during the operation period.  As the passengers are only transient population and will not stay in SHO, and thus the quantities of MSW (general refuse) generated from passengers are negligible.

7.4.38       For the MSW generated from maintenance activities, it is expected that small to a few hundred kg per month will be generated during the operation period.  Plastics, papers and other recyclable wastes should be separated from general refuse and recycled as far as possible.  The remaining refuse would be collected by waste collectors and disposed of at landfills.

7.5              Mitigation of Adverse Environmental Impacts

Construction Phase

7.5.1          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 as far as practicable;

        Recovery and recycling of residual materials where possible; and

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

7.5.2          Based on the waste management hierarchy, waste reduction measures are recommended as follow to reduce impacts and costs arisen from the Project.  Recommendations of good site practices and waste reduction measures have been stated in order to achieve avoidance and minimization of waste generation in the hierarchy. 

Good Site Practices

7.5.3          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;

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

        Preparation of Waste Management Plan (WMP), as part of the Environmental Management Plan (EMP).

Waste Reduction Measures

7.5.4          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; and

        Minimize over ordering and wastage through careful planning during purchasing of construction materials.

7.5.5          In addition to the above measures, other specific mitigation measures are recommended below to minimise environmental impacts during handling, transportation and disposal of wastes.

Construction and Demolition Materials

7.5.6          The C&D materials generated from site clearance, excavation works, and construction of station should be sorted on-site into inert C&D materials (that is, public fill) and C&D waste. To minimise the impact resulting from collection and transportation of C&D materials as far as practicable, C&D waste, such as wood, plastic, steel and other metals should be reused or recycled and, as a last resort, disposed to landfill. A suitable area should be designated within the site for temporary stockpiling of C&D materials and to facilitate the sorting process. Within the stockpile areas, the following measures should be taken to control potential environmental impacts or nuisance:

        Proper handling and storage of waste such as soil by means of covers and/or water spraying system to minimise the potential environmental impact and to prevent materials from wind-blown or being washed away;

        Covering materials during heavy rainfall;

        Locating stockpiles to minimise potential visual impacts;

        Minimising land intake of stockpile areas as far as possible;

        Adopting GPS or equivalent system for tracking and monitoring of all dump trucks engaged for the Project in recording their travel routings and parking locations to prohibit illegal dumping and landfilling of C&D materials; and

        keeping record and analysis of data collected by GPS or equivalent system related to travel routings and parking locations of dump trucks engaged on site.

General Refuse

7.5.7          General refuse should be stored in enclosed bins or compaction units separate from C&D materials and chemical waste.  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.  An enclosed and covered area is preferred to reduce the occurrence of 'wind blown' light materials.

7.5.8          The recyclable component of general refuse, such as aluminium cans, paper and cleansed plastic containers shall be separated from other waste.  Provision and collection of recycling bins for different types of recyclable waste shall be set up by the Contractor.  The Contractor shall also be responsible for arranging recycling companies to collect these materials.

7.5.9          The Contractor shall 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 shall also be provided in the sites as reminders.

Chemical Wastes

7.5.10       If chemical wastes were to be produced at the construction site, the Contractor would be required to register with the EPD as a Chemical Waste Producer, and to follow the guidelines stated in the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes.  

7.5.11       Appropriate containers with proper labels should be used for storage of chemical wastes.  Chemical wastes should be collected and delivered to designated outlet by a licensed collector.  Chemical wastes (e.g. spent lubricant oil) should be recycled at an appropriate facility as far as possible, while the chemical waste that cannot be recycled should be disposed of at either the CWTC, or another licensed facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

7.5.12       Any unused chemicals or those with remaining functional capacity should be collected for reuse as far as practicable.

Sediments

7.5.13       The sediment should be excavated, handled, transported and disposed of in a manner that would minimise adverse environmental impacts.  For minimization of sediment disposal, beneficial reuse will be considered on site as far as practicable during the construction stage before the disposal of excavated sediment.  

7.5.14       Requirements of the Air Pollution Ordinance (Construction Dust) Regulation, where relevant, shall be adhered to during excavation, transportation and disposal of the sediment.

7.5.15       In order to minimise the exposure to contaminated materials, workers shall, if necessary, wear appropriate personal protective equipments (PPE) when handling contaminated sediments.  Adequate washing and cleaning facilities shall also be provided on site.

7.5.16       For off-site disposal, the basic requirements and procedures specified under PNAP No. 252 (ADV-21) shall be followed. Marine Fill Committee (MFC) of CEDD is managing the disposal facilities in Hong Kong for the excavated sediment, while EPD is the authority of issuing marine dumping permit under the Dumping at Sea Ordinance (DASO).

7.5.17       For the purpose of site allocation and application of marine dumping permit and if considered necessary by EPD (Marine Dumping Section), a separate SSTP shall be submitted to EPD for agreement under DASO.  Additional SI works, based on the SSTP, shall then be carried out in order to confirm the disposal arrangements of the excavated sediment.  A Sediment Quality Report (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.

7.5.18       To ensure disposal space is allocated for the Project, the Project Proponent should be responsible for obtaining agreement from MFC on 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.

7.5.19       The excavated sediments is expected to be loaded onto the barge at public barging point of which the exact location will be determined by the contractor(s) and agreed by EPD/CEDD and transported to the designated disposal sites allocated by MFC.  The excavated sediment would be disposed of according to its determined disposal options and PNAP No. 252 (ADV-21).

7.5.20       Stockpiling of contaminated sediments should be avoided as far as possible.  If temporary stockpiling of contaminated sediments is necessary, the excavated sediment should be covered by tarpaulin and the area should be placed within earth bunds or sand bags to prevent leachate from entering the ground, nearby drains and surrounding water bodies.  The stockpiles should be completely paved or covered by linings in order to avoid contamination to underlying soil or groundwater.  Separate and clearly defined areas should be provided for stockpiling of contaminated and uncontaminated materials.  Leachate, if any, should be collected and discharged according to the Water Pollution Control Ordinance (WPCO).

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

7.5.22       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 as specified by the DEP.

Operational Phase

Chemical Wastes

7.5.23       The requirements given in the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes should be followed in handling of chemical waste as in construction phase.  A trip-ticket system would be adopted by the Project Proponent to monitor disposal of chemical waste.

7.5.24       Chemical waste shall be disposed of at appropriate facility such as the CWTC by licensed collectors.  It is expected quantities of chemical wastes to be generated from the SHO and the Reprovisioned SHD would be of similar magnitude as current operation of SHD, i.e. about small to a few hundred litres per month.

Municipal Solid Wastes

7.5.25       The MSW generated from SHO and Reprovisioned SHD will follow the current practice of waste management as adopted in existing SHD operation.  Designated areas will be assigned for proper storage and collection of MSW generated on site. Segregation of MSW will be conducted on site to allow for maximization of recycling opportunities.  It is recommended to place clearly labelled recycling bins at designated locations which could be accessed conveniently.  A reputable waste collector should be employed to remove MSW regularly to minimize potential impacts arising from storage and collection of MSW.

7.5.26       Table 7.6 provides a summary of the various waste types likely to be generated during the construction and operation of the Project, together with the recommended handling and disposal methods.

Table 7.6     Waste Arising, Waste Handling Procedures and Disposal Outlets

Waste Material Type

Generated From

Materials Generated

Total Quantity Generated

Handling Methods/

Reuse

Disposal Outlet

C&D Materials

Construction Phase:

Excavation, Demolition Works, Site Formation and Construction of Station.

Inert C&D materials 每 Rock, Soft Materials and Artificial Hard Materials

1,319,370m3

     Segregation from non-inert C&D materials during stockpiling

     Stockpile area (if required) should be well managed with covers and water spraying system

 

    Public Fill Reception Facilities areas or reclamation sites

Non-inert C&D materials 每 Vegetation, Timber, Papers and Plastics

18,200 m3

     Segregation from inert C&D materials during stockpiling

     Reusable materials should be separated and recycled as far as practicable

Designated Landfill Site to be agreed with EPD/CEDD

General Refuse

Construction Phase: Workforce

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

Construction Phase: 228 kg/day

      Provide on-site collection points together with recycling bins

      Collected by reputable waste collectors

Designated Landfill Site to be agreed with EPD/CEDD

Chemical Waste

Construction and operation phase:
Maint-enance and Operation of Equipments and Machineries

Oils and grease hydraulic fluids, paints, solvents, cleaners etc.

Construction Phase: Small to a Few hundred litres per month

Operation Phase: Small to a Few hundreds litres per month

     Store in compatible containers in designated area on site

     To be collected and recycled by licensed collectors

Chemical Waste Treatment Centre (CWTC) or other licensed facilities

 

Municipal Solid Waste

Operation Phase: Maint-enance and Operation of Equipments and Machineries; Staff and commercial operators

Metal, used fluorescent tubes(1), used welding rods, cleansing materials, discarded electronic equipment, food waste, plastic waste, , papers waste  and office waste etc.

Operation Phase: Small to Few hundreds kg per month generated from maintenance activities; and 130kg/day generated from staff and commercial operators.

     Provide on-site collection points together with recycling bins

     Collected by reputable waste collectors

Refuse transfer station  or recycling facilities

Land-based Sediments

 

Piling works and excavation works for the proposed Replanning Works within the existing SHD and the SHO station construction.

Category L Sediment

 

18,764 m3

      Beneficial reuse on site as far as practicable

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

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

Category M Sediment (passed Tier III - biological screening)

 

2,198 m3

      Beneficial reuse on site as far as practicable

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

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

Category H Sediment (does not require the Tier III biological screening))

864 m3

      Beneficial reuse on site as far as practicable

      Type 2 -Confined marine disposal at marine disposal site(s) allocated by MFC.

Final disposal shall be determined by MFC; typically East Sha Chau

Notes:
(1) If the number of used fluorescent tubes is more than 500, it would be handled as chemical waste in accordance with the Waste Disposal (Chemical Waste)(General) Regulation.

7.6              Evaluation of Residual Environmental Impacts

7.6.1          With the implementation of the recommended mitigation measures for the handling, transportation and disposal of the identified waste arising, adverse residual impact is not expected to occur during the construction and operation of the Project.

7.7              Environmental Monitoring and Audit Requirement

Construction Phase

7.7.1          During the construction period, it is the Contractor*s responsibility to ensure that all waste produced during the construction of the Project are handled, stored and disposed of in accordance with good waste management practices, relevant legislation and waste management guidelines.

7.7.2          Waste materials generated during construction activities, such as C&D materials, are recommended to be audited at regular intervals to ensure that proper storage, transportation and disposal practices are being implemented.  This would ensure the waste generated would be properly disposed of.  The Contractor would be responsible for the implementation of any mitigation measures to minimise waste or mitigate problems arisen from waste materials.

7.7.3          A WMP should be prepared and submitted to the Engineer for approval.  The recommended mitigation measures should form the basis of the WMP. 

Operational Phase

7.7.4          With the implementation of good waste management practices, no adverse environmental impacts is expect to arise, and therefore waste monitoring and audit programme during the operation phase is not required.

7.8              Conclusion

7.8.1          Waste types generated by the construction of this Project are likely to include C&D materials (from excavation and piling works, demolitions of existing structures and site formation), sediment; chemical waste from maintenance of construction plant and equipment and general refuse.  Provided that these wastes are handled, transported and disposed of according to the recommended good site practices, adverse environmental impacts are not expected during the construction phase.

7.8.2          The total volume of excavated sediment generated from the proposed SHO, Stage 1 to 4 of the SHD Replanning Works and the proposed piling works for local access is estimated to be approximately 21,826 m3. Based on the results of the chemical and biological screening, approximately 18,764 m3 of sediment is suitable for Type 1 每 Open Sea Disposal, 2,198 m3 of sediment is suitable for Type 1 每 Open Sea Disposal (Dedicated Sites) and 864 m3 of sediment requires Type 2 每 Confined Marine Disposal in accordance with PNAP No. 252 (ADV-21).  With the implementation of the recommended mitigation measures detailed in Sections 7.5 and in accordance with the requirements of PNAP No. 252 (ADV-21), no adverse environment impacts would be expected from excavation, transportation and disposal of marine sediment.

7.8.3          The main waste types generated during the operation of the SHO and Reprovisioned SHD would be chemical waste and MSW from maintenance activities, commercial operators and staff.  The handling, collection, transportation and disposal practices of the identified waste generated should follow the current practices at other operating railway lines.  It is anticipated that no adverse impacts would arise if the mitigation measures are strictly followed.