Table of Contents

4.    NOISE.. 4-1

4.1      Introduction . 4-1

4.2      Environmental Legislation, Standards and Criteria

4.3      Baseline Conditions . 4-6

4.4      Identification of Noise Sensitive Receivers . 4-6

4.5      Construction Noise Impact Assessment 4-8

4.6      Road Traffic Noise Impact Assessment

4.7      Fixed Noise Sources Impact Assessment 4-19

4.8      Environmental Monitoring and Audit (EM&A) 4-19

4.9      Conclusion . 4-20

 

List of Table

Table 4.1           Construction Noise Standards during Non-restricted Hours

Table 4.2           Acceptable Noise Levels under Technical Memorandum on Noise from Construction Work other than Percussive Piling

Table 4.3           Noise Criteria for Construction Ground-borne Noise

Table 4.4           Construction Ground-borne Noise Criteria during Restricted Hours

Table 4.5           Noise Criteria for Fixed Noise Sources

Table 4.6           Summary of Noise Standards for Different Noise Sources

Table 4.7           Identified Noise Sensitive Receivers and Representative Noise Assessment Points within 300m from Project Boundary

Table 4.8           Summary of Key Construction Works for the Project

Table 4.9           Tentative Plant Inventory for Key Construction Activities

Table 4.10        Summary of Predicted Road Traffic Noise Assessment Results in Year 2027 (Prevailing) and Year 2048 (Unmitigated Scenario)

 


 

List of Figures

Figure 4.1        General Layout Plan with 300m Assessment Area from Project Boundary

Figure 4.2        300m Assessment Area and Locations of Identified Potential Noise Sensitive Receivers

Figure 4.3        Locations of Representative Noise Assessment Points

Figure 4.3.1     Locations of Representative Noise Assessment Points (Sheet 1 of 2)

Figure 4.3.2     Locations of Representative Noise Assessment Points (Sheet 2 of 2)

Figure 4.4        Extent of “Project Roads” under the Project

Figure 4.5        Locations of Low Noise Road Surfacing adopted under “Project Roads” of Proposed TYLL

 

List of Appendices

Appendix 4.1      Photos of Representative Existing Noise Sensitive Receivers

Appendix 4.2      TD Endorsement Email and Hourly Peak Traffic Forecast

Appendix 4.3      Computer Plots of Road Traffic Noise Model

Appendix 4.4      Confirmation with HyD on the Application of LNRS on Existing and Committed / Planned Roads

Appendix 4.5      Predicted Road Traffic Noise Level in Year 2027 and Year 2048

 

                                                

                                                


4.                   NOISE

4.1               Introduction

4.1.1.1      This section presents an assessment on the potential noise impacts arising from the construction and operation of the Project.  The noise impact assessment is conducted in accordance with the requirements of Annex 5 and Annex 13 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO -TM) as well as the requirements set out under Clause 3.4.5 and Appendix C of the EIA Study Brief (No. ESB-359/2023).

4.1.1.2      The potential concurrent projects as identified in Section 2 have been considered in this EIA to address the cumulative impacts.

4.2               Environmental Legislation, Standards and Criteria

4.2.1           General

4.2.1.1      Noise impact has been assessed in accordance with the criteria and methodology given in the Technical Memoranda (TM) under the Noise Control Ordinance (NCO) (Cap. 400), and the EIAO-TM under the Environmental Impact Assessment Ordinance (EIAO) (Cap. 499).

4.2.1.2      The NCO and EIAO provide the statutory framework for noise control.  Assessment procedures and standards are set out in the following TMs:

·       Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM);

·       Technical Memorandum for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites (IND-TM);

·       Technical Memorandum on Noise from Construction Work in Designated Areas (DA-TM);

·       Technical Memorandum on Noise from Construction Work other than Percussive Piling (GW-TM);

·       Technical Memorandum on Noise from Percussive Piling (PP-TM); 

·       EIAO Guidance Note No. 9/2023 – Preparation of Construction Noise Impact Assessment under the EIAO (GN No. 9/2023);

·       EIAO Guidance Note No. 16/2023 – Preparation of Fixed Noise Sources Impact Assessment under the EIAO (GN No. 16/2023); and

·       EIAO Guidance Note No. 12/2023 – Preparation of Road Traffic Noise Impact Assessment under the EIAO (GN No. 12/2023).

4.2.2           Construction Noise

General Construction Works

4.2.2.1      The NCO provides the statutory framework for noise control of construction works, other than percussive piling, using powered mechanical equipment (PME) between the hours of 1900 and 0700 hours or at any time on Sundays and general holidays (i.e. restricted hours).  Noise from construction activities taking place at 0700 – 1900 hours on any day not being a Sunday or general holiday is subject to the Noise Standards for Daytime Construction Activities in Table 1B of Annex 5 of the EIAO-TM.  The criteria are summarised in Table 4.1.  For general construction work to be carried out during non-restricted hours, guidelines on GN No. 9/2023 should be followed.

Table 4.1      Construction Noise Standards during Non-restricted Hours

Uses

Daytime (0700 to1900 hours on any day not being a Sunday or general holiday),

Leq (30mins), dB(A) [1]

·       All Domestic premises,

·       Temporary housing accommodation, Hostels,

·       Convalescent homes, and

·       Homes for the aged.

75

·       Places of public worship,

·       Courts of law, and

·       Hospitals and medical clinics

70

·       Educational Institutions (including kindergartens and nurseries)

70

65 (during examination)

Notes:

[1]   The above standards apply to uses which rely on opened windows for ventilation and are assessed at 1m from the external facade.

Construction Works during Restricted Hours

4.2.2.2      On all days during 1900 and 0700 hours and at any time on Sundays and general holidays, the use of PME for the purpose of carrying out construction work is prohibited unless a Construction Noise Permit (CNP) has been obtained.  A CNP may be granted provided that the Acceptable Noise Level (ANL) for the Noise Sensitive Receivers (NSRs) can be complied with.  ANLs are assigned depending upon the Area Sensitivity Rating (ASR) and are given in Table 4.2.

 Table 4.2    Acceptable Noise Levels under Technical Memorandum on Noise from Construction Work other than Percussive Piling

Time Period

ANL on Different ASR During Restricted Hours (Leq, 5mins, dB(A))

ASR A

ASR B

ASR C

All days during evening (1900 to 2300 hours), and general holidays (including Sundays) during the daytime and evening (0700 to 2300 hours)

60

65

70

All days during the night-time

(2300 to 0700 hours)

45

50

55

 

4.2.2.3      The Noise Control Authority will consider a well-justified CNP application, for construction works within restricted hours as guided by the relevant TMs issued under the NCO.  The Noise Control Authority will take into account contemporary conditions/ situations of adjoining land uses and any previous complaints against construction activities at the site before deciding whether to grant a CNP.  Nothing in the EIA Report should bind the Noise Control Authority in making its decision.  If a CNP is to be issued, the Noise Control Authority should include in the permit any condition it considers appropriate.  Failure to comply with any such conditions will lead to cancellation of the CNP and prosecution under the NCO.

4.2.2.4      Under the DA-TM, the use of five types of Specified Powered Mechanical Equipment (SPME) and three types of Prescribed Construction Work (PCW) within a designated area during restricted hours would require a valid CNP.  The SPME includes hand-held breaker, bulldozer, concrete lorry mixer, dump truck and hand-held vibratory poker. The PCW are:

·       Erecting or dismantling of formwork or scaffolding;

·       Loading, unloading or handling of rubble, wooden boards, steel bars, wood or scaffolding material; and

·       Hammering.

4.2.2.5      In general, it should not be presumed that a CNP would be granted for carrying out PCW within a designated area during restricted hours.  The CNP may be granted for the execution of construction works during restricted hours involving the use of PME and/or SPME if the relevant ANLs and criteria stipulated in the GW-TM and DA-TM can be met.  The ANLs for the use of SPME within a designated area (i.e. those listed in DA-TM) are more stringent (i.e. 15 dB(A) lower than those listed in the GW-TM) to offer additional protection to the population.

Pilling Works during Non-restricted Hours

4.2.2.6      Percussive piling is prohibited between 1900 and 0700 hours on any weekday not being a general holiday and at any time on Sundays or general holiday.  A CNP is required for carrying out percussive piling between 0700 and 1900 hours on any day not being a general holiday.  PP-TM sets out the requirements for working and determination of the permitted hours of operations for the CNP applications.  The permitted hours of operations would be 3, 5 or 12 hours per day depending on the types of percussive piling and the predicted noise impact at NSRs.

Construction Ground-borne Noise during Non-restricted Hours

4.2.2.7      Noise arising from general construction works of the Project during normal daytime (0700-1900 except Sundays and general holidays) is governed by the EIAO-TM.  With reference to the IND-TM under the NCO, the criteria for noise transmitted primarily through the structural elements of the building or buildings should be 10dB(A) less than the relevant ANL.  These criteria apply to all NSRs, such as residential buildings, schools, clinics, hospitals, temples and churches.  Therefore, the ground-borne construction noise criteria are limited to 10 dB(A) below respective ANL stipulated in the GW-TM.

4.2.2.8      The construction ground-borne noise criteria for the representative ground-borne NSR of the Project are tabulated in Table 4.3 below.

Table 4.3      Noise Criteria for Construction Ground-borne Noise

Type of NSR / Assessment Point

Ground-borne Noise Criteria

0700 to 1900 hours on any day not being a Sunday or general holiday

Leq (30mins) dB(A)

·   All Domestic premises,

·   Temporary housing accommodation,

·   Hostels,

·   Convalescent homes, and

·   Homes for the aged

65

·   Places of public worship,

·   Courts of law, and

·   Hospitals and medical clinics

60

·   Educational institutions (including kindergartens and nurseries)

60

 55 (during examination)

Construction Ground-borne Noise during Restricted Hours

4.2.2.9      Similar to air-borne construction noise during restricted hours, NCO also provides statutory control of construction work for ground-borne noise during restricted hours. As discussed in the above section, same principle for ground-borne noise criteria (i.e. ANL-10dB(A) under the IND-TM) shall be adopted.  Therefore, table below summarises the ground-borne construction noise criteria during restricted hours.

Table 4.4     Construction Ground-borne Noise Criteria during Restricted Hours

Time Period

Noise Criteria for Area Sensitivity Rating, dB(A)

ASR A

ASR B

ASR C

All days during evening (1900 to 2300 hours), and general holidays (including Sundays) during the daytime and evening (0700 to 2300 hours)

50

55

60

All days during the night-time

(2300 to 0700 hours)

35

40

45

Blasting

4.2.2.10   There is no statutory procedure or criteria under the NCO and EIAO for assessing the blasting impacts and is therefore beyond the scope of the EIA.  However, the administrative and procedural control of all blasting operations in Hong Kong is vested in the Mines Division of the Civil Engineering and Development Department (CEDD).  The Dangerous Goods Ordinance (Cap. 295) also stipulates that no person shall carry out blasting unless he possesses a valid mine blasting certificate issued by the Mines Division of CEDD.  The Superintendent of Mines will review the application on a case-by-case basis before issuing the Mine Blasting Certificate.  Although there is no statutory noise level for blasting, the noise associated with the removal of debris and rocks are controlled under the EIAO-TM.

4.2.3           Road Traffic Noise

4.2.3.1      For road traffic noise, the following L10(1 hr) criteria stipulated in Annex 5, Table 1A of EIAO-TM are adopted for different types of NSRs which rely on opened window for ventilation. 

·       70 dB(A) at 1 m from the external facades of all domestic premises, temporary housing accommodation, hostels, convalescent homes, and homes for the aged;

·       65 dB(A) at 1 m from the external facades of educational institutions, places of public worship, and courts of law; and

·       55 dB(A) at 1 m from the external facades of hospitals and medical clinics.

4.2.3.2      In addition, reference should also be made to EIAO GN No. 12/2023.

4.2.4           Fixed Noise Sources

4.2.4.1      Fixed noise sources are controlled by Section 13 of the NCO, IND-TM and GN 16/2023.  For planned fixed noise sources, 5dB(A) below the appropriate ANLs as shown in Table 2 of the IND-TM or the prevailing background noise levels (for quiet areas with level 5 dB(A) below the ANL) as recommended in the Annex 5 of EIAO-TM for planning purposes are applied to this study. The ANLs and criteria for different ASRs are summarised in Table 4.5 below.

Table 4.5     Noise Criteria for Fixed Noise Sources

Time Period

Noise Criteria

for Different Area Sensitivity Rating (Leq 30 min, dB(A)) (a), (b)

ANL, dB(A)

ANL-5, dB(A) for
Planned Fixed Noise Sources

ASR A

ASR B

ASR C

ASR A

ASR B

ASR C

Day

(0700 to 1900 hrs)

60

65

70

55

60

65

Evening

(1900 to 2300 hrs)

60

65

70

55

60

65

Night

(2300 to 0700 hrs)

50

55

60

45

50

55

Remarks: 

(a)    The noise criteria apply to uses which rely on opened window for ventilation only.

(b)    The above standards should be viewed as the maximum permissible noise levels assessed at 1 m from the external facade.

4.2.5           Summary of Noise Standards for Different Noise Sources

4.2.5.1      The noise standards for various noise sources as mentioned above are summarised in Table 4.6 below.

Table 4.6     Summary of Noise Standards for Different Noise Sources

Type of NSR

Road Traffic Noise

L10 (1 hr) dB(A

Planned Fixed Noise Sources

(if any)

Leq (30mins) dB(A)

Construction Noise during

Non-restricted Hours

Leq (30mins) dB(A)

Construction Noise during

Restricted Hours

Leq (5mins) dB(A)

General Construction Noise

Ground-borne Noise

General Construction Noise

Ground-borne Noise

·   All Domestic premises,

·   Temporary housing accommodation,

·   Hostels,

·   Convalescent homes, and

·   Homes for the aged

70

(a)

5 dB(A) below the appropriate ANL shown in the IND-TM, i.e.

Daytime and evening time (0700 to 2300)

55 / 60 / 65 for ASR A / B / C respectively.

 

Night-time (2300 to 0700)

45 / 50 / 55 for ASR A / B / C respectively.

 

or

 

(b) the prevailing background noise levels (for quiet areas with level 5 dB(A) below the ANL)

75

65

(a) All evening (1900 to 2300 hours), and general holidays (including Sundays) during the daytime and evening (0700 to 2300 hours),

ANL on difference ASR is

60 / 65 / 70 for ASR A / B / C respectively.

 

(b) All night-time

(2300 to 0700 hours),

ANL on difference ASR is

45 / 50 / 55 for ASR A / B / C respectively.

10 dB(A) below the appropriate ANL shown in the IND-TM,

(a) All evening (1900 to 2300 hours), and general holidays (including Sundays) during the daytime and evening (0700 to 2300 hours),

50 / 55 / 60 for ASR A / B / C respectively.

 

(b) All night-time

(2300 to 0700 hours),

35 / 40 / 45 for ASR A / B / C respectively.

·   Places of public worship, and

·   Courts of law

65

70

60

·   Hospitals and medical clinics

55

70

60

·   Educational institutions (including kindergartens and nurseries)

65

70

65 (during examination)

60

55 (during examination)

4.3               Baseline Conditions

4.3.1           Description of the Noise Environment

4.3.1.1      The proposed TYLL will be constructed from Tsing Yi West to North Lantau across Man Wan Channel and Kap Shui Mun covering three assessment areas in Tsing Yi West, Ma Wan South and North Lantau.

Tsing Yi West

4.3.1.2      The land uses within the Study Area of Tsing Yi are mainly for Industrial (I), Other Specified Uses (OU) and Green Belt (GB) areas.  No existing NSRs are identified within 300m from the Project boundary.  The prevailing noise climate of Tsing Yi West comprises operational noise from industrial use and road traffic noise from Tsing Sha Highway, Tsing Long Highway, Northwest Tsing Yi Interchange and Lantau Link.

Ma Wan South

4.3.1.3      The land uses within the Study Area of Ma Wan South are mainly for OU and GB.   No existing NSRs are identified within 300m from the Project boundary.  The prevailing noise climate of Ma Wan South area is mainly associated with road traffic on Lantau Link, MTR Tung Chung Line and Airport Express Line, and aircraft to and from Hong Kong International Airport. 

North Lantau

4.3.1.4      The land uses within the Study Area of North Lantau are mainly for GB, OU and Undetermined (U).   Village houses and temporary houses/structures are identified in the surrounding area of the Project.  Village houses are mainly located near Tso Wan, while some temporary houses/structures are located near San Po Tsui and Yi Chuen.  The prevailing noise climate is dominated by the road traffic noise from Lantau Link and aircraft noise.

4.3.2           Prevailing Noise Measurements

4.3.2.1      Since no fixed noise sources are proposed under the Project at this stage, prevailing background noise measurements at the existing NSRs are not considered required to determine the standards for evaluating noise impact from fixed noise sources. 

4.4               Identification of Noise Sensitive Receivers

4.4.1.1      In accordance with Annex 13 of the EIAO-TM, all domestic premises, temporary housing accommodation, hostels, convalescent homes, homes for the aged, educational institutions (including kindergartens and nurseries), places of public worship, courts of law, hospitals, medical clinics and any other premises or places that are considered by the Director of Environmental Protection to have similar sensitivity to noise as the above are NSRs.

4.4.1.2      According to the observations from site visits and review of relevant land use plans including Outline Zoning Plans (OZP), NSRs covering all existing, committed and planned noise sensitive uses within 300m of the Project boundary have been reviewed. No committed NSRs have been identified within the 300m assessment area. 

4.4.1.3      As mentioned in Section 2, there are two potential concurrent projects, namely the Ma Wan South Development (MWSD) and the development at Hongkong United Dockyards (HUD development), within the 300m noise assessment area. There is no concrete implementation programme for MWSD and HUD development at the time of this EIA study. In this regard, these developments would not be considered as planned NSRs in this EIA Study.

4.4.1.4      The identified assessment area, existing NSRs and potential planned NSRs are shown in Figure 4.2, while representative noise assessment points (NAPs) are shown in Figure 4.3.  Identified potential NSRs and representative NAPs within 300m assessment area of the Project are listed in Table 4.7 below.  Photos of the representative NSRs are presented in Appendix 4.1.

4.4.1.5      For road traffic noise impact assessment, the first layer of NSRs would provide acoustic shielding to those receivers at further distance behind.  The predicted noise levels at the first layer of NSRs represent the worst-case scenario, and therefore representative NAPs at these NSRs are selected for road traffic noise assessment.

 

Table 4.7      Identified Noise Sensitive Receivers and Representative Noise Assessment Points within 300m from Project Boundary

NSR ID

NSR Description

OZP

Land Use

Use of NSR [1]

No. of Storeys/ max. mPD

Noise Assessment Point ID (NAP ID)

Type of Assessment [2]

Approximate Horizontal Distance from Building Facade to Project Boundary, m

North Lantau

SPT [3]

10 Tai Chuen,

San Po Tsui

(Village House)

Green Belt

 

R

1 storey

SPT1

C

90

YC

Yi Chuen

(Temporary Structure)

Green Belt

 

R

1 storey

YC1

C, T

20

TW

Tso Wan

(Village House and temporary structure)

Green Belt

 

R

2 storeys

TW1

C, T

225

 

1 storey

TW2

C, T

55

Notes:

*     The assessment will only include NSRs which rely on opened windows for ventilation and within 300m assessment area.

[1] Use of NSR:  R - Residential

[2] Type of Assessment: C – Construction Noise Impact Assessment, T – Road Traffic Noise Impact Assessment

[3] There was a difficulty to verify whether this village house is a noise sensitive use during the site survey.  For a conservative purpose, this village house is identified as a representative NSR.

 

NSRs at Tsing Yi West

4.4.1.6      For Tsing Yi side, no existing, committed or planned NSRs within 300m assessment area have been identified.

NSRs at Ma Wan South

4.4.1.7      At Ma Wan, no existing, committed or planned NSRs within 300m assessment area have been identified. 

NSRs at North Lantau

4.4.1.8      There are some existing potential NSRs in North Lantau but no committed and planned developments with noise sensitive uses were identified within 300m assessment area.  These existing NSRs are mainly village houses or temporary structures scattering in San Po Tsui, Yi Chuen and Tso Wan.

4.5               Construction Noise Impact Assessment

4.5.1           Methodology

4.5.1.1      As set out in Appendix C Clause 2.1.2 of the EIA Study Brief (SB), a qualitative assessment is required to identify the major noise sources / activities, and propose corresponding quieter construction method and equipment adopted to demonstrate that no adverse construction noise impact will be associated with the Project.  A summary of key steps for this qualitative construction noise assessment that has been conducted:

·       Determine 300m assessment area from the Project boundary;

·       Identify existing, committed and planned NSRs in the assessment area and select assessment points to represent identified NSRs that may be affected by the works;

·       Summarise construction methods for key construction works;

·       Collate the construction plant inventory for the key construction works;

·       Evaluate the potential impact on the NSRs qualitatively;

·       Examine and recommend all practical mitigation measures, such as alternative construction methodology, quiet plant, silencer, enclosure, etc., to alleviate any potential noise impacts as much as practicable; and

·       Recommend noise mitigation measures that follows Annex 13 of EIAO-TM and EIAO Guidance Note No. 9/2023 on “Preparation of Construction Noise Impact Assessment under the Environmental Impact Assessment Ordinance”.

4.5.2           Identification of Construction Noise Impact

Identification of Assessment Area and NSR

4.5.2.1      According to Appendix C Clause 2.2.1(a) of the EIA SB, the assessment area of construction noise impact assessment shall include areas within 300m from the boundary of the Project and the works of the Project (see Figure 4.1).

4.5.2.2      NSRs and representative NAPs that are affected by construction noise impact are identified and presented in Table 4.7 above and depicted in Figure 4.2 and Figure 4.3.

Tentative Construction Programme

4.5.2.3      Based on the tentative construction programme, most of the construction of TYLL would be completed before year 2033. A summary of key construction works for the Project is shown in Table 4.8.

Table 4.8     Summary of Key Construction Works for the Project

Description

Tentative Construction Programme

Tsing Yi Connection

Q1 2027 to Q2 2031

Suspension bridge over Ma Wan Fairway

Q1 2027 to Q2 2033

Viaduct connecting the two suspension bridges

Q1 2028 to Q4 2031

Suspension bridge over Kap Shui Mun Fairway

Q1 2027 to Q2 2030

North Lantau Interchange

Q1 2027 to Q2 2031

Inventory of Noise Sources

4.5.2.4      Section 2 of this EIA report has described the key project elements and the associated construction methodology.  The potential sources of noise impact during the construction of the Project would be the use of PME for various construction activities.  The main construction works encompass the following:

·       Site formation and construction of at-grade roads, viaducts and road tunnel at North Lantau Interchange;

·       Construction of at-grade roads, viaducts and retaining walls at Tsing Yi Connection;

·       Construction of the Main Bridges of TYLL, including marine reclamations;

·       Modification/realignment of Tsing Sha Highway and Cheung Tsing Highway;

·       Activities related to geotechnical engineering and measures to mitigate natural terrain hazards; and

·       Additional works encompassing slope works/formation, other tunnel operation areas, barging facilities, relocation of existing facilities, landscaping activities, utility installations, etc.

4.5.2.5      The construction programme currently envisioned does not require the use of percussive piling.  In accordance with the list of good practices and state-of-the-art technologies within the industry, the construction methods and equipment below can be employed in this Project:

·       Quieter type blade saws and hydraulic crushers for the purpose of concrete removal during site clearance and road realignment operations;

·       Non-explosive chemical expansion agents and hydraulic splitters for concrete or rock breaking activities;

·       Self-compacting concrete for the purpose of concreting work instead of vibratory poker;

·       Silent piling by press-in method to minimise the impact of existing structures in the construction of North Lantau Interchange and Tsing Yi Connection; and

·       Off-site concreting works for viaduct construction with pre-cast segments.

4.5.2.6      According to the construction methodology envisaged at this stage, the construction activities and their associated tentative PMEs have been outlined in Table 4.9 below.   The plant inventory adopted for the assessment have been confirmed by Project Engineer and HyD (Highways Department).  It should be noted that the Contractor will review and update this tentative construction plant inventory in the upcoming Construction Noise Management Plan (CNMP) based on the available engineering data and considerations at that time.

Table 4.9     Tentative Plant Inventory for Key Construction Activities

Activities

Possible PMEs Required

Site clearance and formation

·       Air compressor

·       Backhoe

·       Breaker

·       Compactor

·       Crane

·       Drill rig

·       Dump truck

·       Excavator

·       Hydraulic splitter

·       Generator

·       Grout mixer

·       Grout pump

·       Hydraulic crusher

·       Lorry

·       Saw

·       Water pump

·       Vibratory poker

·       Concrete pump

 

Reclamation & Seawall Construction Works

·       Air compressor

·       Bulldozer

·       Conveyor belt

·       Grab dredge

·       Crane barge

·       Derrick barge

·       Dump truck

·       Jack-up barge

·       Anchor boat

·       Flat top barge

·       Backhoes

·       Excavator

·       Generator

·       Tugboat

·       Vibratory compactor

·       Water pump

·       DCM barge

·       Cement barge

·       Drilling rig

·       Guard boat

·       Hopper barge

Construction of the Main Bridge of TYLL

·       Air compressor

·       Bar bender and cutter

·       Breaker

·       Cable hoist

·       Concrete lorry mixer

·       Concrete mixer

·       Concrete pump

·       Derrick barge

·       Piling machine

·       Elevator

·       Excavator

·       Generator

·       Hydraulic Slip Form Machine

·       Lorry

·       Mobile crane

·       Saw

·       Strand spinning machine

·       Tower crane

·       Tugboat

·       Vibratory poker

·       Water pump

·       Winch

Construction of tunnel sections at North Lantau Interchange

·       Batching plant

·       Breaker

·       Concrete lorry mixer

·       Concrete mixer

·       Concrete pump

·       Conveyor belt

·       Drill

·       Dumper

·       Dump truck

·       Excavator

·       Generator

·       Grader

·       Grinder

·       Lorry

·       Mobile crane

·       Rock drill

·       Ventilation fan

·       Concrete pump

Construction of portal structures at

North Lantau Interchange

·       Air compressor

·       Bar bender and cutter

·       Concrete lorry mixer

·       Concrete pump

·       Dump truck

·       Excavator

 

·       Generator

·       Lorry

·       Mobile Crane

·       Vibratory poker

·       Water pump

·       Hydraulic splitter

·       Concrete pump

Road works (including road widening, signage, pavement and drainage works)

·       Air compressor

·       Asphalt paver

·       Bar bender and cutter

·       Compactor

·       Concrete lorry mixer

·       Concrete pump

·       Dump truck

·       Excavator

·       Generator

·       Launching girder

·       Lorry

·       Mobile crane

·       Paint liner marker

·       Roller

·       Trailers

·       Vibratory poker

·       Water pump

 

Construction of barging facility

·       Conveyor belt

·       Derrick barge

·       Dump truck

·       Vibratory poker

·       Excavator

·       Mobile crane

·       Tugboat

·       Bar bender and cutter

Setting-up of concrete batching plant

·       Air compressor

·       Breaker

·       Concrete lorry mixer

·       Concrete pump

·       Dump truck

·       Excavator

·       Generator

·       Mobile crane

·       Vibratory poker

·       Water pump

Construction of anchorages for the Main Bridges of TYLL

·       Concrete truck Concrete pump

·       Excavator

·       Dump truck

·       Mobile crane

·       Tower Crane

·       Water pump

·       Vibratory poker

Slope works

·       Breaker

·       Concrete lorry mixer

·       Compactor

·       Drill

·       Drill rig

·       Dump truck

·       Excavator

·       Generator

·       Grout mixer

·       Grout pump

·       Hydraulic crusher

·       Lorry

·       Saw

·       Vibratory poker

·       Water pump

 

Geotechnical works

·       Drilling rig

·       Generator

·       Concrete pump

·       Water pump

·       Vibratory poker

·       Bar bender and cutter

Landscape works

·       Breaker

·       Dump truck

·       Excavator

·       Generator

·       Lorry

·       Mobile crane

·       Saw

4.5.2.7      Apart from the listed PMEs above, the construction of the tunnel would involve drill-and-blast operations during restricted hours.  The Contractor shall obtain the CNPs before commencing any restricted-hour construction activities to ensure compliance and effective noise management.

4.5.3           Evaluation of Construction Noise Impact

Tsing Yi West

4.5.3.1      There are no identified existing, committed and planned NSRs at Tsing Yi area within 300m noise assessment area. Therefore, no construction noise impact at Tsing Yi West is anticipated. 

Ma Wan South

4.5.3.2      There are no identified existing, committed or planned NSRs at Ma Wan South within 300m noise assessment area. Therefore, no construction noise impact at Ma Wan South is anticipated. 

North Lantau

4.5.3.3      There are no committed and planned NSRs within 300m noise assessment area in North Lantau. Only some scattered village houses / temporary structures located in San Po Tsui, Yi Chuen and Tso Wan are classified as potential NSRs as shown in Figure 4.2 and summarised in Table 4.7.

4.5.3.4      For the work sites near San Po Tsui, key construction activities include movement of construction vehicles, construction of barging facilities, construction / operation / demolition of temporary concrete batching plant, etc.  The distance from building facades of the nearest village houses to the works boundary is about 90m. Considered that the houses at San Po Tsui are only 1-storey, with proper implementation of appropriate mitigation measures and good site practices (e.g. use of quality powered mechanical equipment (QPME) / quieter construction methods, use of site hoarding with higher surface density and height, noise barriers, noise enclosures and locating mobile plant as far away as possible and practicable from NSRs, etc.), no adverse construction noise impact on the NSRs at San Po Tsui is anticipated.

4.5.3.5      There are only three 1-storey temporary structures at Yi Chuen which are likely to be residential use and located at about 20m from Project boundary.  They are located at about 70m from the nearest works area of the Lantau Anchorage and about 265m from the works area of the barging facilities.  Major construction activities include slope works, site formation, construction of columns and decks for viaduct sections, etc.  Those construction activities would be partly screened by natural terrain. With proper implementation of appropriate mitigation measures and good site practices (e.g. use of QPME / quieter construction methods, use of site-hoarding with higher surface density and height, noise barriers, noise enclosures and locating mobile plant as far away as possible and practicable from NSRs, etc.), no adverse construction noise impact on the NSRs at Yi Chuen is anticipated.

4.5.3.6      Lots of temporary structures/houses are located at Tso Wan near the coast and upslope.  The nearest horizontal distance from building façade to Project boundary is about 55m.  Major construction activities include slope works, site formation, construction of portal structures and tunnel sections, and construction of slip roads connecting to the HKIW-NEL Link.   As shown in Figure 4.3.2, TW2 is the closest NAP that might be affected during construction phase and operational phase.  TW2 is located at about 210m from the tunnel portal of southbound slip road and about 260m from the tunnel portal of northbound slip road.  Considering that TW2 is screened by natural terrain and located at a certain distance from the construction works areas, no adverse construction noise impact on the NSRs at Tso Wan is anticipated with proper implementation of appropriate mitigation measures and good site practices (e.g.  use of QPME / quieter construction methods, use of site hoarding with higher surface density and height, noise barriers, noise enclosures and locating mobile plant as far away as possible and practicable from NSRs, etc.).

4.5.3.7      Temporary access haul roads at North Lantau for construction vehicles/trucks would be provided during construction phase. However, the haul road alignment cannot be confirmed at this stage as they are subject to the actual site condition and contractor design to facilitate material transportation.  In order to minimise the impacts on existing roads, the Contractor shall i) implement measures to avoid construction traffic during peak hours where practicable, ii) limit the number of construction vehicles during construction phase, and iii) coordinate carefully with concurrent projects to reduce overlapping travel routes and minimise overall induced traffic.

Drill-and-Blast Works at North Lantau

4.5.3.8      While methods such as tunnel boring machine (TBM) for tunnelling works were considered, as medium to hard rocks would be expected in the North Lantau vicinity, the ground conditions would hinder the usage of TBM which is more likely to be employed for softer ground profile.  Furthermore, due to the short length of the tunnel, the adoption of TBM is not cost-effective.  Therefore, blasting was proposed for the purpose of tunnel works. 

4.5.3.9      The initial sections of the tunnel will be excavated by mechanical methods.  Drill-and-blast excavation will then be adopted for the construction of remaining tunnel sections starting from approximately 50m beyond the portal.  The drill-and-blast works would possibly be conducted throughout a 24-hour cycle on a daily basis as the worst-case scenario subject to the granting of CNP.  For safety reason, a metal blast door would be installed at the portal and this blast door would be closed during the blasting works. According to the latest construction methodology, blasting would be conducted daily at each workfront which will be subject to the agreement from the Mines Division of CEDD. Blasting should be carried out outside sensitive hours as far as practicable.  As described in Section 4.2.2.10, the noise generated during the blast does not fall under the NCO and EIAO.  Considering that the blasting works will be carried out inside the metal blast door and will only last for few seconds per blast and be infrequent, therefore it will not cause adverse air-borne nor ground-borne construction noise impacts to NSRs in the vicinity. 

4.5.3.10   Besides, the Contractor will be required to post highly visible warning notices/signs at suitable locations to warn the public that blasting will take place. These warning signs will be posted near the intended blasting location, even though all blasts will be conducted underground. The Contractor is required to state the blasting date and time on the notice.

Surface Blasting at North Lantau

4.5.3.11   Having reviewed the site formation methods, to address the potential geological constraints and time implication arising from the use of other methods (e.g. expansion agents), it is considered that blasting would be the most feasible method for site formation in this Project.

4.5.3.12   Surface blasting works would also be required at several rock cut slope sites along the alignment where large portions of rock will be excavated.  Surface blasting would be conducted daily at each workfront which will be subject to the agreement from the Mines Division of CEDD.  Blasting should be carried out during daytime only. Similar to the underground blasting, the surface blasting works will only last for very short duration and be infrequent, it will not cause adverse air-borne nor ground-borne noise impacts to NSRs in the vicinity.

4.5.3.13   Besides, the Contractor will be required to post highly visible warning notices/signs at suitable locations to warn the public that blasting will take place. These warning signs will be posted near the intended blasting location. The Contractor is required to state the blasting date and time on the notice.

Consideration of Cumulative Impacts

4.5.3.14   Section 2 has identified a list of concurrent projects that would be considered in this EIA to address the cumulative impacts.

4.5.3.15   The works areas of proposed Route 11 would be outside 300m from the identified NSRs at Lantau, no cumulative impacts would be anticipated.

4.5.3.16   There are two slip roads that would be connected to the main alignment of Hong Kong Island West - Northeast Lantau Link (HKIW-NEL Link) at North Lantau.  It is anticipated that the EIA for HKIW-NEL Link would consider all committed projects in the vicinity, including but not limited to TYLL during its subsequent study.  Like any other studies by government, it is anticipated that they will also implement all the best practices to abate construction noise impacts where practicable.  On this basis, adverse cumulative construction noise impacts from these projects are therefore not anticipated.

4.5.3.17   For the concurrent projects of “Road P1 (Tai Ho - Sunny Bay Section)”, “Sunny Bay Development” and “Underground quarrying contract at Tsing Yi North”, since no existing noise sensitive receivers are located within 300m from these concurrent projects, no cumulative noise impact assessment of these concurrent projects are considered necessary.  For the concurrent projects of MWSD and HUD development, considering that no concrete implementation programme nor approved rezoning proposal / planning application and associated design plan of MWSD and HUD development are available at the present stage, the cumulative impacts on these projects will be assessed in separate studies conducted by their respective project proponents.

4.5.3.18   The Project Proponent will further review the cumulative noise impact caused by the Project and concurrent projects (if any) within 300m assessment area in the subsequent CNMP submission at later construction phase to ensure that there is no adverse construction noise impact.

4.5.4           Mitigation of Construction Noise Impact

4.5.4.1      Due to the tight construction programme and limited buffer distances, construction noise exceedances are anticipated at some NSRs.  The following mitigation measures have been considered and confirmed to be practical by the Project Engineers:

·       Good site practices to limit noise emissions at the source;

·       Use of QPME and quieter construction methods;

·       Use of temporary noise barriers, movable noise barrier, noise enclosure, noise insulating fabric, silencer, etc., to screen noise from construction equipment; 

·       Install acoustic tunnel door or enclosure at tunnel portals for construction activities to be carried out inside tunnel during restricted hours;

·       Alternative use of plant items within one worksite, wherever practicable; and

·       Providing sufficient separation distance between NSRs and items of PME.

4.5.4.2      Quieter construction method such as silent piling by press-in method is adopted as an alternative to traditional sheet piling.  A sheet pile is clipped and pressed under the ground. Noise can be minimised by hydraulic press-in sheet piles with drilling simultaneously for piling works at harder ground.  The noise impact can also be further reduced as the piling works can be completed within the shorter duration by using this method. 

4.5.4.3      The Contractor may be able to obtain particular models of plant that are quieter than the PMEs given in GW-TM.  The use of quality PME associated with the construction works is prescribed in EPD’s QPME database, which contains the SWLs for quality/quiet PME of various types, brands and models.

4.5.4.4      The use of hydraulic breaker for rock or concrete breaking would inevitably generate high level of noise as the operation principle of hydraulic breaker is through percussive striking actions of its chisels.  Quieter rock or concrete breaking equipment (e.g. hydraulic crusher/splitter or hand-held breaker with QPME label) in some activities should be considered in the CNMPs as a mitigation measure, such as breaking large boulder into smaller pieces on site for removal during site formation works, breaking seawall, breaking concrete plinth/shallow foundation during demolition of temporary building structures, and in seawall works for breaking existing large rock fill to finer rock fill for reuse.  This quieter rock breaking equipment would create less noise impact to NSRs.  The Contractor should, subject to the actual site conditions, proactively adopt quieter rock breaking equipment, hydraulic crusher/splitter or non-mechanical breaking method (e.g. use of chemical expansion agent) to carry out the demolition works, where practicable.  The Contractor should select appropriate quieter construction method / equipment as appropriate to minimise any potential construction noise impact to the environment. The Contractor should explore other quieter construction method and equipment to further minimise the potential construction noise impact.

4.5.4.5      Movable noise barriers or noise enclosures would be erected to provide screening from the construction plant.  Noise barriers would be most effective when located immediately adjacent to the PME and can reduce the noise level by 5 dB(A) for movable PME and by 10 dB(A) for stationary PME.  The Contractors shall be responsible for design of the noise barrier with due consideration given to the size of the PME and the requirement of intercepting the line of sight between the NSRs and PME.  The barrier material of movable noise barrier should have at least 10 kg/m2 surface density.  Purpose-built acoustics barrier can be used to screen noise from particular items of PME or noisy construction activities.  The direct line of sight between the PME and the NSRs should be totally screened by a substantial barrier such that the PME will not be visible when viewed from any window, door or other opening in any facade of the NSR.  A noise reduction of 10 dB(A) is assumed for purpose-built noise barrier.  Full enclosures can be considered as an alternative to shelter relatively static plant including generator. The provision of full enclosure is expected to provide 15 dB(A) noise reduction for static PME.

4.5.4.6      Careful scheduling of construction activities and grouping of PMEs within a construction site and liaison between contractors of nearby construction sites could avoid multiple noisy construction activities/construction equipment to be conducted/used at the same time within close proximity.  Hence, the cumulative construction noise level could be reduced.

4.5.4.7      The benefits of these techniques can vary according to specific site conditions and operations. The environmental noise climate would certainly be improved with these control practices, although the improvement can only be quantified during implementation when specific site parameters are known.

4.5.4.8      For village houses / temporary structure with residential use at North Lantau which are close to the construction sites, it is recommended to install site hoarding with higher surface density and height to provide extra noise attenuation to protect these NSRs.

4.5.5           Construction Noise Management Plan

4.5.5.1      According to Appendix C Clause 2.4 of the EIA SB, a CNMP shall be prepared and submitted to the Director. The CNMP shall contain the quantitative construction noise impact assessment, the adopted quieter construction method and equipment, noise mitigation measures and the construction noise impact monitoring and audit programme, with reference to the updated and identified noise mitigation measures once available and in any case before the tender invitation if there is any change to the construction noise mitigation measures in the EIA report and before the commencement of construction of the project.  Any technical constraint that would hinder the use of these quieter construction method and equipment shall be evaluated and clearly recorded in the assessment.

4.5.5.2      The CNMP shall include an implementation schedule clearly listing out the mitigation measures, the implementation party, locations and timing of implementation.  Mitigation measures recommended and requirements specified in the CNMP will be fully implemented by the Contactor.

4.5.5.3      Cumulative construction noise impact from the concurrent projects, if any, should be considered and evaluated in the CNMP.  The status of potential planned developments (i.e. MWSD and HUD development) should be reviewed at the time of preparing the CNMP.

 

 

4.6               Road Traffic Noise Impact Assessment

4.6.1           Methodology

4.6.1.1      Road traffic noise impact assessment is predicted based on the traffic flows, following strictly the procedures stipulated in the “Calculation of Road Traffic Noise (CRTN)” (1988) published by Department of Transport, UK.  Road traffic noise is presented in terms of noise levels exceeded for 10% of the one-hour period having the peak traffic flow (i.e. L10,1hr dB(A)).  A 2.5 dB(A) facade reflection and correction factors for effects due to gradient, distance, view angle, road surface and barriers would be included in the assessment.

4.6.1.2      Traffic noise levels were predicted based on the maximum traffic projections within 15 years upon operation of the roadworks, with reference to Section 5.1 in Annex 13 of the EIAO-TM.  Based on the project programme, the operation of the Project would tentatively commence in Year 2033.  The assessment year for road traffic noise is taken as Year 2048 which is the maximum traffic projection within 15 years upon operation of the Project.  For the prevailing scenario, traffic data for year 2027 before the commencement of construction works of the Project was adopted. Since the morning peak hour traffic flows and vehicle compositions would be generally higher than afternoon peak, therefore AM peak was selected for assessment.  The AM peak hour traffic forecast adopted in this assessment and TD’s endorsement are presented in Appendix 4.2.

4.6.1.3      Road traffic noise from the road network, including both the “Project Roads” and “Other Roads” (existing and other planned Roads) within the 300m assessment area, would be considered in the assessment to predict the traffic noise impact on the representative NSRs.  The extent of “Project Roads” and “Other Roads” is presented in Figure 4.4.  All roads are described as one of the following:

·       “Project Roads”: roads that are completely new or existing road section with major modification or substantial changes in alignment or characters due to the proposed Project like section of Tsing Sha Highway and Cheung Tsing Highway; and

·       “Other Roads”: roads with the road alignments remain unchanged or without substantial alteration by the proposed Project, and any planned roads (i.e. Route 11 and HKIW-NEL Link) under other projects.

4.6.1.4      The characteristics of the road network such as road width, surface type, traffic flow, use of Low Noise Road Surfacing (LNRS), and existing and committed noise mitigation measures have been considered in the assessment.  Locations of existing and committed LNRS as well as existing and committed noise mitigation measures had made reference to EPD’s Environmental Database Central Portal and EIA report of Route 11.

4.6.1.5      For HKIW-NEL Link, location of LNRS adopted had made reference to the Guidance Notes on Road Surface Requirements for Expressways and High Speed Road issued by Highways Department.

4.6.1.6      In accordance with the EIAO GN No. 12/2023, the direct mitigation measures would be considered or proposed if adverse noise impact due to “Project Roads” is predicted.  If the NSRs are affected by noise from other existing roads, direct mitigation measures are required to reduce the noise from the concerned “Project Roads” to a level that it:

·       is not higher than the standard; and

·       has no significant contribution (less than 1.0 dB(A)) to the overall noise level, if the overall noise level (i.e., noise from “Project Roads” together with “Other Roads”) exceeds the noise standard.

4.6.1.7      According to the EIAO GN No. 12/2023, in cases where direct noise mitigation measures alone are not adequate in mitigating noise to a level of existing NSRs in compliance with the EIAO-TM noise criteria, indirect technical remedies (ITR) in the form of acoustic insulation and air-conditioning is to be considered as a “last resort” to mitigate the residual noise impact.  The eligibility for ITR is suggested to be tested against the following three criteria:

(i)        The predicted overall noise level, in L10(1hour), exceeds the noise standard in accordance with EIAO-TM; and

(ii)       The predicted overall noise level is at least 1.0 dB(A) more than the prevailing traffic noise level, i.e. existing total traffic noise level before commencement of any road works under the Project; and

(iii)      The contribution from the Project Roads to the increase in the predicted overall noise level must be at least 1.0 dB(A).

4.6.2           Prediction and Evaluation of Road Traffic Noise Impact

Prevailing Scenario (Year 2027)

4.6.2.1      As stated in Section 4.4 and Table 4.7, no existing NSRs at Tsing Yi and Ma Wan were identified within the 300m noise assessment area.  As such, road traffic noise assessment for prevailing scenario in Year 2027 was only conducted for existing NSRs in North Lantau.  Referring to Table 4.10 below, the predicted prevailing noise level at Yi Chuen is 58 dB(A) which is far below the noise criterion.

Unmitigated Scenario (Year 2048)

4.6.2.2      The “Project Roads” extent is shown in Figure 4.4 and location of representative NAPs that might be affected by road traffic noise have been identified and presented in Table 4.7.  Computer plots of the traffic noise model are presented in Appendix 4.3.

4.6.2.3      Agreement on the noise assessment area, representative NAPs and road sections to be included in the road traffic noise assessment had been obtained from EPD in accordance with Appendix C of the EIA SB.

4.6.2.4      In accordance with HyD's guidance notes on road surface requirements, standard road surfacing materials, which also serve as LNRS, would be applied to road sections of new road projects with design speed of 80 km/hr or above.  Such surfacing materials provide a noise reduction performance of approximate 2.5dB(A) as compared with concrete paving.  It was confirmed with HyD that LNRS would be applied to the road segments of TYLL with 80 km/hr or above under unmitigated scenario (Appendix 4.4 refers).  The presumed extents of LNRS at proposed TYLL are presented in Figure 4.5.

4.6.2.5      The predicted road traffic noise levels in Year 2048 at representative NAPs under unmitigated scenario are presented in Table 4.10 and detailed in Appendix 4.5. 

Table 4.10    Summary of Predicted Road Traffic Noise Assessment Results in Year 2027 (Prevailing) and Year 2048 (Unmitigated Scenario)

NSR ID

NAP ID

Noise Criteria,

L10 1-hr

dB(A)

Prevailing Noise Level in Year 2027,

 L10 1hr dB(A) [1]

Max. Predicted Noise Level in Year 2048, L10 1hr dB(A)

Max. “Project Roads” Contribution, dB(A) [3]

Floor with Noise Exceedance

Mitigation Measure required?

Project Roads

Other Roads

Overall

Existing NSRs at Yi Chuen

YC

YC1

70

58

59

59

62

-

-

N

Existing NSRs at Tso Wan

TW

TW1

70

-  [2]

49

61

61

-

-

N

 

TW2

70

-  [2]

53

60

61

-

-

N

Notes:

[1] The prevailing year assessment was based on the traffic data for year 2027 before the commencement of construction works of the Project.

[2] No existing roads within 300m from this NAP that no value be simulated.

[3] Only presented for the NAPs with overall noise levels exceeding the noise criteria.

 

Identification of Assessment Area and NSRs

4.6.2.6      Identified NSRs and representative NAPs that are affected by road traffic noise impact are identified and presented in Table 4.7 above and depicted in Figure 4.2 and Figure 4.3.

Existing Representative NSRs

4.6.2.7      As mentioned in Section 4.4, existing NSRs are only identified at North Lantau, while there are no existing NSRs within 300m assessment area at Tsing Yi West and Ma Wan.  As shown in Table 4.10 above, the predicted road traffic noise levels at representative existing NAPs would range from 61 to 62 dB(A) and hence noise mitigation measures are not required.

4.6.2.8      As shown in Figure 4.3, TW2 is the only representative NAP within 300m from the tunnel portals, and it is located at an elevation much lower than the portals.  Considering the tunnel portals would be screened by the viaduct structure itself or terrain and separated by more than 200m from TW2, adverse noise impact from the portals is not anticipated.

Committed/Planned NSRs

4.6.2.9      There are no committed/planned NSRs within 300m assessment area. 

Consideration of Cumulative Impacts

4.6.2.10   As discussed in above Section 4.4.1.3, there is no concrete implementation programme for MWSD and HUD development at the time of this EIA study. Besides, the proposed developments have not yet obtained the rezoning application approval. The cumulative impact from these projects (if any) would be considered in separate studies of these projects by respective project proponents. Notwithstanding the above, with the implementation of practicable mitigation measures, no insurmountable road traffic noise impact in operational phase is anticipated.    

4.6.3           Mitigation Measures

Existing Representative NSRs

4.6.3.1      There are no exceedances of road traffic noise levels at existing NSRs, therefore no mitigation measures would be required for existing NSRs. As no noise exceedance was predicted at existing NSRs under unmitigated scenario, eligibility assessment for indirect noise mitigation measures is not considered required.

Committed/Planned NSRs

4.6.3.2      There are no committed/planned NSRs within 300m from project boundary.  

4.6.4           Evaluation of Residual Road Traffic Nosie Impact

4.6.4.1      According to Section 4.6.3, adverse residual road traffic noise impact due to the Project is not anticipated. 

4.7               Fixed Noise Sources Impact Assessment

4.7.1.1      At the time of this EIA study, it has been discussed with CEDD that a ventilation building would be designed and constructed under HKIW-NEL Link, while the Overhead Ventilation Duct (OHVD) inside the northbound tunnel under TYLL connecting to the ventilation building under HKIW-NEL Link would be designed by TYLL.  There would be no ventilation building / ventilation shaft under TYLL at this stage, and the OHVD inside the tunnel (with implementation of proper noise mitigation measures, e.g. silencer) is not expected to cause adverse noise impact to the surroundings. Nevertheless, the provision of individual / a combined ventilation building would be further reviewed at later stage to take into account the latest implementation programme of HKIW-NEL Link and TYLL. If the individual ventilation building is confirmed to be constructed and operated under TYLL project, the Fixed Noise Source Management Plan (FNMP) will be prepared to include the prevailing background noise survey, the quantitative fixed noise source impact assessment, noise mitigation measures and monitoring and audit programme, and submitted to EPD before commencement of construction of the Project.

4.7.1.2      The proposed Administration Building under Route 11 at Ng Kwu Leng would serve TYLL as well.  The administration building of Route 11 is located more than 300m from any identified NSRs and there will be a considerable level difference between the ventilation building of HKIW-NEL Link and identified NSRs at Tso Wan, adverse fixed noise impact arising from both administration building and ventilation building is not anticipated. 

4.7.1.3      Since no fixed noise sources would be proposed under this Project at this stage, fixed noise sources impact assessment is not considered required under this EIA study. 

4.8               Environmental Monitoring and Audit (EM&A)

4.8.1           Construction Noise

4.8.1.1      Noise monitoring should be carried out as part of the EM&A programme for the construction phase of the Project to check compliance with the construction noise criteria.

4.8.1.2      A CNMP should evaluate the potential construction noise impacts based on the latest construction programme and construction plant inventory, and to assess the effectiveness and practicality of all proposed noise mitigation measures.  The CNMP would be prepared before the tender invitation and commencement of construction works.  The implementation of the mitigation measures recommended in CNMP should also be audited as part of the EM&A programme.  Details of the EM&A requirements are provided in a stand-alone EM&A Manual.

4.8.2           Operation Noise

4.8.2.1      As no adverse traffic noise impact arising from the Project is anticipated, EM&A requirements are not considered necessary.

4.8.2.2      As no fixed noise sources would be proposed by the Project, EM&A requirements are not considered necessary.

4.9               Conclusion

4.9.1           Construction Noise

4.9.1.1      An assessment on construction noise has been conducted according to the requirements in the EIA SB.  With the adoption of proposed noise mitigation measures, including the use of QPME, use of quieter equipment/method, use of higher surface density site-hoarding, use of noise barrier / enclosure, etc., adverse noise impact arising from construction works of the Project is not anticipated.  Nevertheless, a CNMP, which contains a quantitative construction noise impact assessment, mitigation measures and monitoring and audit programme, will be submitted before the tender invitation and commencement of construction works.

4.9.2           Operation Noise

4.9.2.1      A road traffic noise impact assessment has been conducted according to the requirements in EIA SB.  No adverse road traffic noise impact would be anticipated for all representative NSRs.

4.9.2.2      As there are no planned fixed noise sources under the Project identified at this stage, fixed noise sources impact assessment was not carried out under this EIA.