Chapter Title Page

3. Noise Impact 3-1

3.1 Introduction_ 3-1

3.2 Environmental Legislation, Standards and Guidelines_ 3-1

3.2.1 Construction Phase_ 3-1

3.2.2 Operation Phase_ 3-3

3.3 Assessment Area, Noise Sensitive Receivers and Description of Existing Environment 3-5

3.3.1 Assessment Area_ 3-5

3.3.2 Noise Sensitive Receivers (NSRs) 3-5

3.3.3 Description of Existing Environment 3-9

3.4 Construction Phase Impact 3-10

3.4.1 Airborne Noise_ 3-10

3.4.2 Ground-borne Noise_ 3-26

3.5 Operation Phase Impact 3-31

3.5.1 Airborne Noise_ 3-31

3.5.2 Ground-borne Noise_ 3-53

3.6 Environmental Monitoring and Audit 3-60

3.6.1 Construction Phase_ 3-60

3.6.2 Operation Phase_ 3-60

3.7 Conclusion_ 3-60

3.7.1 Construction Phase_ 3-60

3.7.2 Operation Phase_ 3-60

Tables

Table 3.1:__ Noise Standards for Daytime Construction Activities_ 3-1

Table 3.2:__ Ground-borne Noise Criteria (L_{eq 30min}, dB(A)) 3-3

Table 3.3:__ Area Sensitivity Rating_ 3-4

Table 3.4:__ Acceptable Noise Level for Operation Airborne Railway Noise_ 3-4

Table 3.5:__ Acceptable Noise Level for Operation Ground-borne Railway Noise_ 3-5

Table 3.6:__ Acceptable Noise Level for Fixed Plant Noise_ 3-5

Table 3.7:__ Representative Noise Sensitive Receivers_ 3-7

Table 3.8:__ Assessment Period for Representative NSRs_ 3-9

Table 3.9:__ Key Noise Sources to the Existing NSRs_ 3-10

Table 3.10:_ Unmitigated Construction Airborne Noise Impact near Admiralty Station, L_{eq (30mins)} dB(A) 3-14

Table 3.11:_ Unmitigated Construction Airborne Noise Impact near Nam Fung Portal, L_{eq (30mins)} dB(A) 3-14

Table 3.12:_ Unmitigated Construction Airborne Noise Impact near Ocean Park Station, L_{eq (30mins)} dB(A) 3-15

Table 3.13:_ Unmitigated Construction Airborne Noise Impact near Wong Chuk Hang Station and Depot, L_{eq (30mins)} dB(A) 3-15

Table 3.14:_ Unmitigated Construction Airborne Noise Impact near Wong Chuk Hang Nullah and Aberdeen Channel, L_{eq (30mins)} dB(A) 3-15

Table 3.15:_ Unmitigated Construction Airborne Noise Impact near Lei Tung Station and Entrances, L_{eq (30mins)} dB(A) 3-16

Table 3.16:_ Unmitigated Construction Airborne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A) 3-16

Table 3.17:_ Unmitigated Construction Airborne Noise Impact near Telegraph Bay Barging Point, L_{eq (30mins)} dB(A) 3-16

Table 3.18:_ Unmitigated Construction Airborne Noise Impact near Lee Nam Road Barging Point, L_{eq (30mins)} dB(A) 3-16

Table 3.19:_ Unmitigated Construction Airborne Noise Impact near Chung Hom Shan Magazine Site, L_{eq (30mins)} dB(A) 3-16

Table 3.20:_ Quieter PME Recommended for Adoption during Construction Phase_ 3-18

Table 3.21:_ Noise Mitigation Measures for Certain PME during Construction Phase_ 3-19

Table 3.22:_ Mitigated Construction Airborne Noise Impact near Admiralty Station, L_{eq (30mins)} dB(A) 3-20

Table 3.23:_ Mitigated Construction Airborne Noise Impact near Nam Fung Portal, L_{eq (30mins)} dB(A) 3-20

Table 3.24:_ Mitigated Construction Airborne Noise Impact near Ocean Park Station, L_{eq (30mins)} dB(A) 3-20

Table 3.25:_ Mitigated Construction Airborne Noise Impact near Wong Chuk Hang Station and Depot, L_{eq (30mins)} dB(A) 3-20

Table 3.26:_ Mitigated Construction Airborne Noise Impact near Wong Chuk Hang Nullah and Aberdeen Channel, L_{eq (30mins)} dB(A) 3-20

Table 3.27:_ Mitigated Construction Airborne Noise Impact near Lei Tung Station and Entrances, L_{eq (30mins)} dB(A) 3-21

Table 3.28:_ Mitigated Construction Airborne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A) 3-21

Table 3.29:_ Mitigated Construction Airborne Noise Impact near Telegraph Bay Barging Point, L_{eq (30mins)} dB(A) 3-22

Table 3.30:_ Mitigated Construction Airborne Noise Impact near Lee Nam Road Barging Point, L_{eq (30mins)} dB(A) 3-22

Table 3.31_ Cumulative Construction Airborne Noise Impact in the vicinity of Admiralty 3-22

Table 3.32:_ Cumulative Construction Airborne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A) 3-23

Table 3.33_ Cumulative Construction Airborne Noise Impact in the vicinity of Telegraph Bay Barging Point 3-23

Table 3.34:_ Summary of Residual Impact 3-23

Table 3.35:_ Reference Vibration Level Based on Measurements_ 3-27

Table 3.36:_ Source Vibration Velocity of Octave Band Frequency for Hydraulic Breaker 3-27

Table 3.37:_ Wave Propagation Properties of Soil 3-27

Table 3.38:_ Adjustment Factor for Building Coupling Loss (BCF) 3-28

Table 3.39:_ Adjustment Factor for Building Structure Attenuation (BSA) 3-28

Table 3.40:_ Building Structure Attenuation (BSA) for SIL(E) Study 3-28

Table 3.41:_ Building Structure Resonance (BSR) for SIL(E) Study 3-29

Table 3.42:_ Room Correction Factors_ 3-29

Table 3.43:_ Unmitigated Construction Ground-borne Noise Impact near Admiralty Station, L_{eq (30mins)} dB(A) 3-30

Table 3.44_ Unmitigated Construction Ground-borne Noise Impact near Nam Fung Portal, L_{eq (30mins)} dB(A) 3-30

Table 3.45_ Unmitigated Construction Ground-borne Noise Impact near Sham Wan Tower, L_{eq (30mins)} dB(A) 3-30

Table 3.46:_ Unmitigated Construction Ground-borne Noise Impact near Lei Tung Station, L_{eq (30mins)} dB(A) 3-30

Table 3.47_ Unmitigated Construction Ground-borne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A) 3-30

Table 3.48 :_ Reference Train Noise Level 3-32

Table 3.49:_ Revenue Train Service Operation Detail (Ultimate Weekly) 3-36

Table 3.50:_ Unmitigated Railway Noise during Daytime and Evening Time (0700-2300) 3-36

Table 3.51:_ Unmitigated Railway Noise during Night Time (2300-0700) 3-37

Table 3.52:_ Unmitigated Railway Noise in L_{eq (24hrs)} 3-38

Table 3.53:_ Proposed Location of Noise Barriers/ Enclosure for Existing Uses_ 3-39

Table 3.54:_ Mitigated Railway Noise during Daytime and Night Time_ 3-40

Table 3.55:_ Railway Noise during Daytime (0700-2300), with Scenario for Existing NSRs mitigation measures_ 3-41

Table 3.56:_ Railway Noise during Night time (2300-0700), with Scenario for Existing NSRs mitigation measures_ 3-41

Table 3.57:_ Railway Noise in L_{eq (24hrs)} dB(A), with Scenario for Existing NSRs mitigation measures_ 3-41

Table 3.58:_ Proposed Location of Additional Noise Barriers/ Enclosures for Planned Uses_ 3-42

Table 3.59:_ Mitigated Railway Noise during Daytime and Night Time_ 3-43

Table 3.60:_ Summary of Fixed Plant Noise Sources_ 3-44

Table 3.61:_ Maximum SWLs of the Fixed Plant 3-48

Table 3.62:_ Correction Factor for Maximum SWL of the Fixed Plant 3-50

Table 3.63:_ Correction Factor for Maximum SWL of the Fixed Plant 3-51

Table 3.64:_ Operation Ground-borne Noise Prediction Results (Unmitigated) 3-56

Table 3.65_ Operation Ground-borne Noise Prediction Results (Mitigated) 3-58

Figures

Figure 3.1 Preferred Alignment and Assessment Area

Figure 3.2 The First Layer of Affected Noise Sensitive Receivers (Sheet 1 of 9)

Figure 3.3 The First Layer of Affected Noise Sensitive Receivers (Sheet 2 of 9)

Figure 3.4 The First Layer of Affected Noise Sensitive Receivers (Sheet 3 of 9)

Figure 3.5 The First Layer of Affected Noise Sensitive Receivers (Sheet 4 of 9)

Figure 3.6 The First Layer of Affected Noise Sensitive Receivers (Sheet 5 of 9)

Figure 3.7 The First Layer of Affected Noise Sensitive Receivers (Sheet 6 of 9)

Figure 3.8 The First Layer of Affected Noise Sensitive Receivers (Sheet 7 of 9)

Figure 3.9 The First Layer of Affected Noise Sensitive Receivers (Sheet 8 of 9)

Figure 3.10 The First Layer of Affected Noise Sensitive Receivers (Sheet 9 of 9)

Figure 3.11 Representative Noise Sensitive Receivers (Sheet 1 of 9)

Figure 3.12 Representative Noise Sensitive Receivers (Sheet 2 of 9)

Figure 3.13 Representative Noise Sensitive Receivers (Sheet 3 of 9)

Figure 3.14 Representative Noise Sensitive Receivers (Sheet 4 of 9)

Figure 3.15 Representative Noise Sensitive Receivers (Sheet 5 of 9)

Figure 3.16 Representative Noise Sensitive Receivers (Sheet 6 of 9)

Figure 3.17 Representative Noise Sensitive Receivers (Sheet 7 of 9)

Figure 3.18 Representative Noise Sensitive Receivers (Sheet 8 of 9)

Figure 3.19 Representative Noise Sensitive Receivers (Sheet 9 of 9)

Figure 3.20 Representative Noise Sensitive Receivers near Telegraph Bay Barging Point

Figure 3.21 Representative Noise Sensitive Receivers near Chung Hom Shan Magazine Site

Figure 3.22 Schematic Configuration of Movable Noise Barrier

Figure 3.23 Schematic Configuration of Full Noise Enclosure for PME

Figure 3.24 Typical Cross Section of Viaduct Structure with Structural Frame

Figure 3.25 Extent of Noise Mitigation Measures for Railway Noise (Scenario for Existing NSRs)

Figure 3.26 Extent of Noise Mitigation Measures for Railway Noise (Scenario for Existing NSRs)

Figure 3.27 Extent of Noise Mitigation Measures for Railway Noise (Scenario for Existing NSRs)

Figure 3.28 Extent of Noise Mitigation Measures for Railway Noise (Scenario for Existing and Planned NSRs)

Figure 3.29 Extent of Noise Mitigation Measures for Railway Noise (Scenario for Existing and Planned NSRs)

Figure 3.30 Extent of Noise Mitigation Measures for Railway Noise (Scenario for Existing and Planned NSRs)

Figure 3.31 Schematic Cross Section of Noise Barrier/ Semi-enclosures (Sheet 1 of 3)

Figure 3.32 Schematic Cross Section of Noise Barrier/ Semi-enclosures (Sheet 2 of 3)

Figure 3.33 Schematic Cross Section of Noise Barrier/ Semi-enclosures (Sheet 3 of 3)

Figure 3.34 Location of Fixed Plant at Admiralty Station

Figure 3.35 Location of Fixed Plant at Hong Kong Park

Figure 3.36 Location of Fixed Plant at Nam Fung Portal Ventilation Building

Figure 3.37 Location of Fixed Plant at Ocean Park Station

Figure 3.38 Location of Fixed Plant at Wong Chuk Hang Station

Figure 3.39 Location of Fixed Plant at Wong Chuk Hang Depot

Figure 3.40 Location of Fixed Plant at Lei Tung Station and Entrance

Figure 3.41 Location of Fixed Plant near Sham Wan Tower

Figure 3.42 Location of Fixed Plant at South Horizons and Entrance

Figure 3.43 Location of Fixed Plant at Lee Wing Street Plant Building

Figure 3.44 Noise Mitigation Measures for Operation Ground-borne Noise near South Horizons Station

Appendices

Appendix 3.1 Construction Plant Inventory (Unmitigated)

Appendix 3.2 Unmitigated Construction Airborne Noise Impact

Appendix 3.3 Construction Plant Inventory (Mitigated)

Appendix 3.4 Mitigated Construction Airborne Noise Impact

Appendix 3.5 Unmitigated Construction Ground-borne Noise Impact

Appendix 3.6 Target Speed Profile and Vertical Profile of SIL(E)

Appendix 3.7 Sample Calculation of Operation Airborne Noise Assessment (Unmitigated Scenario)

Appendix 3.8 Operation Airborne Noise Assessment (Unmitigated Scenario)

Appendix 3.9a Sample Calculation of Operation Airborne Noise Assessment (Scenario for Existing NSRs)

Appendix 3.9b Sample Calculation of Operation Airborne Noise Assessment (Scenario for Existing and Planned NSRs)

Appendix 3.10a Operation Airborne Noise Assessment (Scenario for Existing NSRs)

Appendix 3.10b Operation Airborne Noise Assessment (Scenario for Existing and Planned NSRs)

Appendix 3.11 Sample Calculation of Fixed Plant Noise Assessment

Appendix 3.12 Force Density Level for the M-Stock train measured in WIL EIA

Appendix 3.13 Adjustment Factors for Operation Ground-borne Noise Assessment

Appendix 3.14a Sample Calculation of Operation Ground-borne Noise Assessment (Unmitigated Scenario)

Appendix 3.14b Sample Calculation of Operation Ground-borne Noise Assessment (Mitigated Scenario)

3. Noise Impact

3.1 Introduction

This section has evaluated and assessed the potential noise impact likely to arise from the proposed Project during both the construction and operation phases. The noise impact from the proposed Project can be divided into airborne and ground-borne during the construction and operation phases. The assessment has been based on the criteria and guidelines for evaluation and assessing noise impact as stated in Annexes 5 and 13 of the EIAO-TM and NCO and covered the scope outlined in Clause 3.4.1 of the EIA Study Brief.

3.2 Environmental Legislation, Standards and Guidelines

3.2.1 Construction Phase

3.2.1.1 General Construction Activities during Non-Restricted Hours

Noise impacts arising from general construction activities other than percussive piling during the daytime period (07:00-19:00 hours of any day not being a Sunday or general holiday) shall be assessed against the noise standards tabulated in Table 3.1 below.

Table 3.1: Noise Standards for Daytime Construction Activities

Noise Sensitive Uses	0700 to 1900 hours on any day not being a Sunday or general holiday, Leq (30 min), dB(A)
All domestic premises including temporary housing accommodation	75
Hotels and hostel
Educational institutions including kindergarten, nurseries and all others where unaided voice communication is required	70 65 during examination

Source: EIAO-TM, Annex 5, Table 1B - Noise Standards for Daytime construction Activities

Note: The above noise standards apply to uses, which rely on opened windows for ventilation.

The noise levels shall be assessed at 1m from the external façade.

The above standards are for assessment purposes only and shall be met as far as practicable. All practicable mitigation measures shall be exhausted and the residual impacts are minimised.

3.2.1.2 General Construction Activities during Restricted Hours

Noise impacts arising from general construction activities (excluding percussive piling) conducted during the restricted hours (19:00-07:00 hours on any day and anytime on Sunday or general holiday) and percussive piling during anytime are governed by the Noise Control Ordinance (NCO).

For carrying out of any general construction activities involving the use of any Powered Mechanical Equipment (PME) within restricted hours, a Construction Noise Permit (CNP) is required from the Authority under the NCO. The noise criteria and the assessment procedures for issuing a CNP are specified in Technical Memorandum on Noise from Construction Work Other Than Percussive Piling (GW-TM) under the NCO.

The use of Specified PME (SPME) and/or the carrying out of Prescribed Construction Work (PCW) within a Designated Area (DA) under the NCO during the restricted hours are also prohibited without a CNP. The relevant technical details in Technical Memorandum on Noise from Construction Work in Designated Areas (DA-TM) under NCO can be referred.

Designated areas, in which the control of SPME and PCW shall apply, are established through the Noise Control (Construction Work Designated Areas) Notice made under Section 8A(1) of the NCO. According to the Designated Area defined under the NCO (effective from 1 January 2009), all the works area of this project will fall within these areas. As such, the application for CNP for any general construction activities involving the use of any PME shall refer to the GW-TM only. However, the Contractor has the responsibility to check the latest status and coverage of the Designated Areas at time of construction of the project.

According to the construction programme, most of the proposed construction works will be carried out during non-restricted hours. It is also considered necessary to maintain twenty-four hour working inside the tunnel to achieve the required rate of progress due to uncertain geological conditions and fault zones and, the planned construction method necessitates twenty-four hour working to ensure an efficient work cycle. However, those works would be carried out only inside tunnels and at locations away from NSRs, especially at LET and SOH, thus, the potential noise impact to NSRs would be minimal.

In case the proponent needs to evaluate whether these construction works during restricted hours are feasible in the context of programming construction works, reference should be made to the relevant technical memoranda issued under the NCO. Regardless of the results of construction noise impact assessment for restricted hours, the Noise Control Authority will process Construction Noise Permit (CNP) application, if necessary, based on the NCO, the relevant technical memoranda issued under the NCO, and the contemporary condition/situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP.

3.2.1.3 Ground-borne Noise

Noise arising from general construction works during normal working hours is governed by the EIAO-TM under the EIAO as shown in Table 3.1. The Technical Memorandum for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites (IND-TM) under the NCO stipulates that noise transmitted primarily through the structural elements of building, or buildings, shall be 10 dB(A) less than the relevant Acceptable Noise Level (ANLs).

Based on the same principle for the ground-borne noise criteria (i.e. ANL-10 dB(A) under the IND-TM), the ground-borne construction noise levels inside domestic premises and schools shall be limited to 65 dB(A) and 60 dB(A) respectively when compared to the EIAO-TM.

For construction works conducted on general holidays, Sundays and weekdays during evening (1900-2300 hrs) and night time (2300-0700 hrs) the following day, the ground-borne construction noise level shall be limited to 10 dB(A) below the respective ANLs for the Area Sensitivity Rating appropriate to those NSRs affected by the Project. A summary of these criteria is given in Table 3.2 below:

Table 3.2: Ground-borne Noise Criteria (L_{eq 30min}, dB(A))

NSR type	Ground-borne Noise Criteria ^(1), dB(A)
	Daytime (0700-1900)^(2) except general holidays and Sunday	Daytime (0700-1900) during general holidays and Sundays and all days during Evening (1900-2300 hrs)	Night-time (2300 – 0700 hrs)
All domestic premises including temporary housing accommodation	65	50/55/60^(3,4)	35/40/45^(3,4)
Hotels and hostel
Educational institutions including kindergarten, nurseries and all others where unaided voice communication is required	60 55 (for during examination)	N/A^(5)	N/A^(5)
Notes: (1) Noise descriptor for daytime noise except general holidays and Sunday and other periods are Leq (30min) and Leq (5min) respectively. Measurement shall be carried out at an internal location representative of normal occupancy of the building. For residential building, measurement shall be conducted in the bedroom of the apartment. (2) The standards are for assessment purposes only and shall be met as far as practicable. All practicable mitigation measures shall be exhausted and the residual impacts are minimised. (3) Based on the Basic Noise Level for NSRs with Area Sensitivity Ratings of A, B, and C detailed in the Technical Memorandum on Noise From Construction Work Other Than Percussive Piling. (4) Construction Noise Permit is required for works during this period. (5) No sensitive use in Education institutions during evening and night-time period is assumed except those specified.

3.2.1.4 Blasting

There are no statutory procedures and criteria under the NCO and EIAO for assessing the airborne noise impacts of blasting, hence the airborne noise impact generated by this activity is 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 (General) Regulations, Chapter 295 also stipulates that no person shall carry out blasting unless he/she possesses a valid mine blasting certificate to be 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.

3.2.2 Operation Phase

3.2.2.1 Area Sensitivity Rating (ASR)

For the operational railway noise (airborne, structure re-radiated, and ground-borne) and fixed plant noise assessments, the ANLs for the NSRs are determined based on the ASR.

ASR is defined in the IND-TM. The ASR depends on the type of area and the degree of impact that Influencing Factors (IFs) have on the NSRs and is determined from Table 3.3 below. Industrial area, major road or the area within the boundary of Hong Kong International Airport shall be considered to be an IF.

Table 3.3: Area Sensitivity Rating

Type of Area Containing NSR	Degree to which NSR is affected by IF
	Not Affected	Indirectly Affected	Directly Affected
(i) Rural area, including country parks or village type developments	A	B	B
(ii) Low density residential area consisting of low-rise or isolated high-rise developments	A	B	C
(iii) Urban area	B	C	C
(iv) Area other than those above	B	B	C

3.2.2.2 Airborne Railway Noise

In accordance with Annex 5 of the EIAO-TM, noise from rail operation shall be assessed in accordance with the requirements of stipulated in NCO.

The total airborne noise (direct radiated plus airborne structure re-radiated noise) from SIL(E) operation shall comply with the noise level criteria (i.e. the ANL) laid down in the IND-TM.

For a given ASR, The airborne noise criteria for SIL(E) are shown in Table 3.4 below:

Table 3.4: Acceptable Noise Level for Operation Airborne Railway Noise

Time Period	Area Sensitivity Rating			Remark
	A	B	C
Day and Evening (0700- 2300)	60	65	70	-
Night (2300-0700)	50	55	60	Lmax of 85dB(A) based on EIAO requirement

Note : ANL is determined in terms of L_A,_{eq (30min)} assessed at 1m from the external facade

For completeness and as required in the Clause 3.4.1.3 (vi) (c) of the EIA Study Brief, L_{A,eq (30 min)}, L_{A,eq (24 hr)} and L_A,max noise levels will be calculated and presented for the representative airborne NSRs.

3.2.2.3 Ground-borne Railway Noise

With reference to the TM-Places under the NCO, the criteria for noise transmitted primarily through the structural elements of the building or buildings should be 10 dB(A) less than the relevant acceptable noise level (ANL). The same criteria are applied to all residential buildings, schools, clinics, hospitals, temples and churches.

The operation ground-borne noise criteria for the representative NSRs along SIL(E) alignment are tabulated in Table 3.5 below.

Table 3.5: Acceptable Noise Level for Operation Ground-borne Railway Noise

Time Period	Area Sensitivity Rating
	A	B	C
Day and Evening (0700- 2300)	50	55	60
Night (2300-0700)	40	45	50

3.2.2.4 Fixed Plant Noise

Fixed plant noise is controlled under the NCO and shall comply with the ANLs laid down in the Table 2 of the IND-TM. For a given ASR, the ANL is given by Table 3.6 below: -

Table 3.6: Acceptable Noise Level for Fixed Plant Noise

Time Period	Area Sensitivity Rating
	A	B	C
Day (0700 to 1900 hours)	60	65	70
Evening (1900 to 2300 hours)
Night (2300 to 0700 hours)	50	55	60

As stipulated in Annex 5 of the EIAO-TM, the noise standard for planning purposes for fixed noise source are (a) 5 dB(A) below the appropriate ANL, or (b) the prevailing background noise levels (For quiet areas with level 5 dB(A) below the ANL).

3.3 Assessment Area, Noise Sensitive Receivers and Description of Existing Environment

3.3.1 Assessment Area

The “base assessment area” is defined as 300m from the proposed railway alignment and the works areas in accordance with the requirement of the EIA Study Brief (ref. ESB-181/2008).

The proposed alignment and the respective assessment areas are presented in Figure 3.1.

3.3.2 Noise Sensitive Receivers (NSRs)

3.3.2.1 Selection of Representative NSRs

Existing Receivers

Desktop reviews and confirmatory site surveys have been carried out to identify existing NSRs within the study areas in accordance with the EIAO-TM requirements.

Planned Receivers

Relevant Outline Zoning Plans, Outline Development Plans and Layout Plans have also been reviewed to identify any planned NSRs of development already approved by the Town Planning Board.

For the ex-Canadian Hospital site at Wong Chuk Hang, two assessment points have been selected within the site for the operational noise impact assessment. The allowed maximum height for development at the ex-Canadian Hospital site is +50 mPD as advised by Planning Department, the parameter has been adopted in the assessment.

The bus depot site adjacent to the OCP station which is currently zoned for G/IC use, two assessment points have been selected within the respective site for the operational noise impact assessment. According to the latest Draft OZP No.S/H15/25, the allowed maximum height for development at the G/IC site is 4-storey high. This parameter has been taken into in the assessment.

For the site adjacent to the WCH Depot which is zoned for residential use (R(A)), it is formerly the Wong Chuk Hang Estate where demolition has been completed. Three assessment points have been selected within the site for the operational noise impact assessment. As the planning parameter of the development details of the R(A) site are not available at the time of preparing this EIA, in order to ensure the height (or number of floors) above the site which would be worst affected by railway noise has been considered in the assessment and also the necessary mitigation measures, if required, noise level has been predicted at each floor until it has shown plateau off. This thus determines the number of storeys to be assessed for the future development above the WCH Depot. Hence the number of floors has been assessed for the site do not imply any building height for the future development.

The new campus of the Singapore International School in Wong Chuk Hang next to the existing campus is due to be completed in May 2011 according to the latest available information.

An approved hotel development (A/H 15/206) is located at South Horizons close to the SOH station.

NSRs nearest to the noise sources are selected as representative NSRs for the worst-case scenario assessments of construction, operational railway and fixed plant noise impacts.

A summary of all selected representative NSRs for the assessment study is tabulated in Table 3.7. Figures 3.2 to 3.10 show the locations of the first layer of NSRs within the assessment areas. Figures 3.11 to 3.21 show the locations of all representative NSRs selected for assessments.

Table 3.7: Representative Noise Sensitive Receivers

Most of the NSRs listed in Table 3.7 are assessed for all time periods. However, some of the NSRs are not in use in certain time periods during the day and thus no assessment is carried out. The assessment periods for the representative NSRs are summarised in Table 3.8.

Table 3.8: Assessment Period for Representative NSRs

Assessment Period	NSR Type/ID	Remarks
Day Period Only	Schools, Kindergarten, Nurseries and Temple (except those specified in this table)	With no evening or night time activities
Day and Evening Periods Only	Holy Spirit Seminary (HSS1, HSS2 and HSS4)	Evening courses are offered
	CMA Lei Tung Child Care Centre (CMA)	Open between 0745 and 2000
All Periods	Residential premises	Nil

3.3.2.2 Planned Hotel Developments along Heung Yip Road

Based on the latest approved Outline Zoning Plan (i.e. Aberdeen & Ap Lei Chau Outline Zoning Plan No. S/H15/24 gazetted on January 2007), most areas along Heung Yip Road is zoned as Other Specified Uses (OU - Business). Noise sensitive developments, such as Hotels, Education Institution, Library etc., could be developed in these OU areas upon approval by the Town Planning Board (TPB). Approved hotel developments along Heung Yip Road have been identified including application no.s A/H15/196, A/H15/202, A/H15/207, A/H15/210, A/H15/216, A/H15/217, A/H15/222 and A/H15/234.

According to the Environmental Assessment (EA) reports for the hotel developments available for inspection at the Town Planning Board (ref. A/H15/216, A/H15/217 and A/H15/222), the guestrooms for the planned hotel developments will be provided with central air conditioning and will not rely on opened windows for ventilation. It is therefore assumed that other planned hotel developments in this area will be also provided with central air conditioning and not rely on opened windows for ventilation. Hence, no airborne noise assessment will be carried out for these planned hotel developments in accordance with EIAO-TM.

3.3.2.3 Other Special Consideration

Based on our site observations and information provided by MTRCL, the following NSRs do not rely on opened windows for ventilation. Therefore, the following NSRs would not be assessed for airborne noise impact assessment in accordance with guideline provided in the EIAO-TM:

¡ Police College Tactical Training Complex;

¡ St. Paul Co-educational Primary School at Nam Fung (noise sensitive façade with line of sight to the works area is completely blocked by an assembly hall which is noise insulated); and

¡ Island Shangri-La Hotel (SLH) in Admiralty.

Based on latest information available, the planned new campus of Singapore International School (SIS2) along Police School Road would commence for use in 2011/2012 academic year, hence no construction airborne noise impact assessment would be carried out before 2011/2012 academic year.

3.3.3 Description of Existing Environment

Site inspection along the proposed SIL(E) have been conducted from May 2008 to March 2009 to identify the existing environment. Admiralty is located on the northern side of Hong Kong Island which mainly comprise of mixed commercial and residential areas; Ocean Park and Wong Chuk Hang are located on the southern side of Hong Kong Island which mainly comprise of low density residential area and industrial area, while Lei Tung Estate and South Horizons mainly comprise of high-rising residential area. Key sources of noise impact to the existing NSRs are summarised in Table 3.9 below.

Table 3.9: Key Noise Sources to the Existing NSRs

Location	Key Noise Sources
Admiralty (ADM)	Road traffic noise from Queensway Road
Ocean Park (OCP)	Road traffic noise from Aberdeen Tunnel Road
Wong Chuk Hang (WCH)	Road traffic noise from Wong Chuk Hang Road, Heung Yip Road, Police School Road, Nam Long Shan Road and the Wong Chuk Hang Industrial area
Lei Tung Estate (LET)	Road traffic noise from Ap Lei Chau Bridge Road
South Horizons (SOH)	Road traffic noise from South Horizon Drive and Lee Nam Road

As discussed in Section 3.2.2.4, the recommended EIAO-TM assessment criteria for fixed noise sources is 5 dB(A) below the appropriate ANL set out in the IND-TM or the prevailing background noise level where the prevailing noise level is 5 dB(A) below the appropriate ANL. Based on site inspection along the proposed SIL(E) during May 2008 to March 2009, the existing environment was found dominated by road traffic and community noise. It is expected that the background noise levels along the areas of SIL(E) are not likely lower than the regarding ANL – 5 dB(A), hence the 5 dB(A) below the appropriate ANL set out in the IND-TM has been adopted for the fixed plant noise assessment criteria.

3.4 Construction Phase Impact

3.4.1 Airborne Noise

3.4.1.1 Identification of Noise Source

The construction of the proposed SIL(E) would be divided into sections; station by station and involve several construction activities which are detailed in Appendix 3.1. Figure 3.11 to Figure 3.21 show the locations of work sites/ work areas of the Project. The detailed construction programme is given in Appendix 2.3.

The potential source of noise impact during the construction phase of the proposed SIL(E) would mainly be the use of Powered Mechanical Equipment (PME) in various construction activities.

It should be noted that some works areas would mainly for material storage and site facilities. These works areas include the eastern part of Harcourt Garden (W8b), area to the north of Harcourt Road, ex-Canadian Hospital site (W6), western part of Aberdeen Bridge (B8) and soccer pitch near Ap Lei Chau Estate (W2).

It is expected that most of the construction activities would be conducted during daytime, i.e. 0700-1900 on any day not being Sundays or general holidays. Tunnelling works are expected to be extended to the restricted hours defined under the NCO. However, those works would be carried out inside tunnels only. Thus the potential noise impact to NSRs would be minimal. Other than tunnelling works, works such as the erection of viaduct segment which will require temporary closure of traffic lanes of Aberdeen Tunnel Road and Wong Chuk Hang Road are deemed unavoidable to be carried out in the restricted hours. The Contractor will apply CNP for carrying out works during the restricted hours.

The major construction activities of different work areas are described in the following paragraphs.

Admiralty Station (ADM)

There are two major work sites, namely Harcourt Road and Hong Kong Park will be assigned for the construction of the Admiralty Station.

Most of the area of Harcourt Garden will be required for the construction for the station. On the eastern side of Harcourt Garden, it will be used for the site office, material storage and plant occupied areas. Over half of the area will be occupied for the construction of the cut-and-cover box for SIL(E) and Shatin to Central Link (SCL).

The other small site in Hong Kong Park will be required for the shaft construction. The main ventilation shaft for the tunnel will be constructed at the works site at Hong Kong Park on Supreme Court Road opposite the Island Shangri-la Hotel.

Nam Fung Portal (NFP)

The large ex-Canadian Hospital site at Nam Fung Road will be the portal connecting the 3.5km tunnel running from ADM station. A significant amount of spoil will be generated from the tunnel excavation and three works areas in the vicinity of the portal will be used for the spoil stockpile. The works area also supports the construction of tunnel box and the viaducts towards Ocean Park. A ventilation building will also be constructed at the portal entrance. It is envisaged that construction of the ventilation building and the tunnel portal will involve extensive excavation and site formation work. During construction, slope stabilization, pile piling or pre-bored H piling work will also be carried out. The alignment will be in form of an enclosed concrete box structure through the ex-Canadian Hospital site (shown in Figure 2.1.3).

Due to the large amount of rock generated from the tunnel, a rock crushing plant with noise enclosure installed will be located on site next to the tunnel portal. The crushed rocks will be transferred out of the site for disposal.

Ocean Park Station (OCP)

The proposed development site will be a major work site for the construction of the OCP station. Most of the site area will be used for site office, plant and material storage, and the other areas will be used for the construction of viaduct sections.

Wong Chuk Hang Depot (WCD)

The majority of ex-Wong Chuk Hang Estate site will be excavated for the construction of the station and the depot.

At the beginning of the site formation, works mainly involves utilities diversion, hoarding erection and removal of trees and the top hard materials. After that, a large portion of works area at the depot centre will be excavated to the formation level, rock crushing would be carried out in the site. The rock crushing plant will be enclosed. Pipe pile walls will be installed along the site perimeter and bored piles will be constructed in different zones. After the site formation work, the construction will proceed at the central depot area, where the pad footings and other structural works will be carried out. A concrete batching plant would be in operation on-site after the piling works and site formation. The noise from the concrete batching plant operation is considered to be minimal as it is an enclosed structure. The PME involved in the use of the batching plant have been considered in the assessment.

Wong Chuk Hang Station (WCH)

Wong Chuk Hang Station will be situated to the north of the Wong Chuk Hang Depot. The proposed construction work includes the construction of the station and the approaching viaducts.

The construction of the station will interface with the re-construction works of Staunton Creek Nullah in Wong Chuk Hang, where the existing nullah will be decked for a length of about 600m along Heung Yip Road between Tai Wong Ye Temple and Police School Road.

Lei Tung Station (LET)

Lei Tung will be a deep underground station with entrances, ventilation shafts and fireman’s access provided at ground level. After passing through the Ap Lei Chau Bridge, the viaduct section will enter the cut-and-cover tunnel at Ap Lei Chau Drive.

The construction of the cut-and-cover tunnel and the portal will be carried out in two stages. The first stage will be carried out in the work site of the existing Harbour Mission School and along Ap Lei Chau Bridge Road. Upon the completion of first stage works, Ap Lei Chau Drive will be shifted eastwards on the reinstated work site to allow the second stage of open excavation work. The construction of the cut and cover section of the tunnel will also involve pipe piling and slope stabilization work. Two station entrances will be constructed by excavating vertical shafts and adits will be constructed by drill and blast method. Slope stabilization and pipe piling work will be needed at the Ap Lei Chau Main Street entrance, namely Entrance A. A ventilation building will also be constructed by cutting into existing slope at Lee Wing Street.

South Horizons Station (SOH)

The SOH station under Yi Nam Road will be underground and constructed by the cut-and-cover method. The proposed works areas will be founded by mini-bored piles socketed in rock and bounded by screen walls. The works areas at Yi Nam Road will also include construction of three entrances and the portal. The construction of the SOH station has been designed in stages at different works areas with temporary decking over to maintain traffic flow at Yi Nam Road connecting Lee Nam Road, South Horizons Drive and the bus terminal at South Horizons Phase 4 while underground works could still be carried out.

Part of the rock slope at Lee Nam Road will be excavated for the construction of the SOH plant building and slope stabilization work will also be needed.

Major mucking out activities will be carried out via the construction adit at the Lee Wing Street Plant Building site connecting the tunnel and the spoil will be further transferred to the Lee Nam Barging Point by a fully-enclosed overhead conveyor belt system although conventional method by trucks is also a viable alternative for spoil removal from the adit to the barging point.

Telegraph Bay Barging Point (TGB)

Telegraph Bay Barging Point is situated on the seafront, where barging activities will mainly be carried out for the eastern portion of the site. The site will mainly take up spoil materials transported from WCH Depot and Nam Fung Portal.

Lee Nam Road Barging Point (LNR)

Lee Nam Road Barging Point will mainly handle the spoil materials generated from works sites in south of Hong Kong.

Major construction activities include temporary spoil disposal in the site area, dump truck hauling within the site and unloading activities to the barges from trucks and conveyor belts.

Chung Hom Shan Magazine Site (CHK)

The area is located to the south of Chung Hom Shan, in a disused quarry located at the end of a road that passes a PCCW satellite receiving station. The paved access road with slight overgrowth is closed to the public from Chung Hom Kok. The site is situated at a disused platform at the end of the road.

Wah Kwai Works Area (WKW)

Wah Kwai works area is situated on the seafront, where it is an open field and wasteland as shown in Figure 2.6.10. This work area is intended mainly for nursery use.

Blasting

The tunnel section of the proposed alignment will mainly be constructed by drill and blast method. As mentioned in Section 3.2.1.4, blasting is under the control of the Dangerous Goods Ordinance. Therefore, the contractor shall obtain a blasting permit from the Mines Division of CEDD before carrying out the blasting. The Contractor shall enclose a method statement including manner of working and protective measures to protect adjacent land and property when blasting is carried out.

3.4.1.2 Assessment Methodology

In accordance with EIAO-TM Annex 13, the assessment of construction noise impact arising from works other than percussive piling has been based on standard acoustic principles, and the guidelines given in GW-TM issued under the NCO where appropriate. Reference has also been made to the approach given in the Guidance Note titled “Preparation of Construction Noise Impact Assessment under the Environmental Impact Assessment Ordinance” (GN 9/2004). Where the sound power level (SWL) of any PME could not be found in the relevant TM, reference has been made to BS 5228: Part I: 2009, previous similar studies or from measurements taken at other sites in Hong Kong.

The construction noise assessment has been carried out on a bi-weekly basis from the commencement of the Project. The construction tasks of the Project taking place concurrently within 300m of a given NSR are considered to contribute to the cumulative impact at that NSR. Noise sources from the areas greater than this distance have been excluded from the assessment.

A project-specific plant inventory for each construction task of each stage together with the number and type of PME that are considered practical and adequate for carrying out the works during the non-restricted hours has been derived and is presented in Appendix 3.1. The construction programme is presented in Appendix 2.3. The plant inventory has been provided as an option and the contractor may propose an alternative plant schedule should it be considered necessary and appropriate.

The assessment is based on the cumulative SWL of PME likely to be used for each location, taking into account the construction period in the vicinity of the receiver location. To predict the noise level, PME was divided into groups required for each discrete construction task. The objective was to identify the worst case scenario representing those items of PME that would be in use concurrently at any given time. The sound pressure level (SPL) at a NSR from each construction task was calculated, depending on the number of plant and distance from receiver. The overall noise level at the NSR was then predicted by adding up the SPLs at the NSRs of all concurrent construction tasks.

Some of the work tasks have to be carried out underground and in a completely enclosed environment. No noise contribution is assumed from these tasks. For other works to be carried out under deck, assuming a surface density of more than 10 kg/m² for the deck cover, a noise reduction of 20 dB(A) has been applied for the activities carried out underground.

In considering the shielding effect from the existing topography features for the Chung Hom Shan Magazine site, a noise reduction of 10 dB(A) has been assumed.

A positive 3 dB(A) façade correction was added to the predicted noise levels in order to account for the facade effect at each NSR.

The Essential Public Infrastructure Works (EPIWs) and other reprovisioning works would be constructed concurrently with the Project. The cumulative impact from these construction projects has been assessed and presented in below sections.

3.4.1.3 Prediction and Evaluation of Environmental Impact

Due to the extensively developed and densely populated nature of Wong Chuk Hang and Ap Lei Chau, it is unavoidable that construction of such a large-scale railway network would cause noise impacts to the surrounding residences, especially during construction phase of the Project. To strike a balance between the need for providing a railway system to locals and the public concerns on the adverse impacts, the following have been considered during the design of the Project to alleviate the construction noise impacts as far as practicable:

¡ Minimise the number of PME;

¡ Quieter construction method such as (i) use of press-in piling method instead of mini-bored pile for pipe pile walls and (ii) using road ripper instead of excavator mounted breaker for road breaking;

¡ Works would be implemented in phases, where possible, in order to reduce the number of PME required to be on-site.

It is proposed to excavate an adit at the Lee Wing Street Plant Building site near the Lee Nam Barging Point intercepting the railway tunnel between LET and SOH stations. Spoil from the excavation of LET and SOH stations and the LET to SOH running tunnels will be removed through this adit. The spoil will be further transferred to the Lee Nam Barging Point by a fully-enclosed overhead conveyor belt system. By adopting this approach for spoil removal, construction noise impacts can be reduced as the shaft at which mucking out activities would take place would be located relatively distant from NSRs.

Based on the construction programme in Appendix 2.3 and the proposed plant inventory in Appendix 3.1, the predicted construction noise impact for the unmitigated scenario has been summarised in Table 3.10 to Table 3.19 below with detailed calculations given in Appendix 3.2.

Table 3.10: Unmitigated Construction Airborne Noise Impact near Admiralty Station, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
NLH	Residential	63-82	75	Yes
RP	Residential	63-85	75	Yes
PH	Residential	70-81	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.11: Unmitigated Construction Airborne Noise Impact near Nam Fung Portal, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
GP	Residential	48-77	75	Yes
SFE1	Residential	51-79	75	Yes
UGA	Educational	49-77	70	Yes
YSM1	Convalescent Home	58-81	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.12: Unmitigated Construction Airborne Noise Impact near Ocean Park Station, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
WCHH2	Residential	58-75	75	No
SW2	Residential	60-79	75	Yes
SW4	Residential	45-82	75	Yes
PC4	Residential	58-82	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.13: Unmitigated Construction Airborne Noise Impact near Wong Chuk Hang Station and Depot, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
PC1	Residential	63-89	75	Yes
PC2	Residential	64-87	75	Yes
SIS1	Educational	60-87	70	Yes
SIS2	Planned educational	61-89	70	Yes
CPS	Educational	63-92	70	Yes
GG	Residential	61-89	75	Yes
SMH1	Home for the elderly	65-86	75	Yes
SMH2	Home for the elderly	64-86	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.14: Unmitigated Construction Airborne Noise Impact near Wong Chuk Hang Nullah and Aberdeen Channel, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
TWGH1	Convalescent Home	61-83	75	Yes
TWGH2	Convalescent Home	66-79	75	Yes
HSS1	Educational	59-87	70	Yes
HSS2	Educational	59-86	70	Yes
HSS4	Educational	58-81	70	Yes
OC1	Residential	60-76	75	Yes
OC2	Residential	60-76	75	No
SWT1	Residential	61-84	75	Yes
SWT2	Residential	58-86	75	Yes
SWT3	Residential	58-84	75	Yes
TLC1	Educational	56-81	70	Yes
YOK	Educational	55-83	70	Yes
YOC4	Residential	59-87	75	Yes
SMB	Residential	57-83	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.15: Unmitigated Construction Airborne Noise Impact near Lei Tung Station and Entrances, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
AKPS	Educational	64-71	70	Yes
CMA	Nursery	66-78	75	Yes
LTE2	Residential	60-78	75	Yes
LDN	Nursery	66-78	75	Yes
LTE4	Residential	60-78	75	Yes
NEC	Home for the elderly	67-79	75	Yes
LTE5	Residential	61-79	75	Yes
SPC	Educational	59-71	70	Yes
LMCC	Educational	60-71	70	Yes
YCB	Residential	78-99	75	Yes
SFB	Residential	86-95	75	Yes
HFB	Residential	81-88	75	Yes
LFB	Residential	75-88	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.16: Unmitigated Construction Airborne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SOH5	Residential	59-93	75	Yes
SOH6	Residential	59-92	75	Yes
SOH7	Residential	61-87	75	Yes
SOH8	Residential	60-89	75	Yes
PBPS	Educational	67-88	70	Yes
ALCE1	Residential	68-71	75	No
HKPS	Educational	72-73	70	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.17: Unmitigated Construction Airborne Noise Impact near Telegraph Bay Barging Point, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
AT1	Residential	72-78	75	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.18: Unmitigated Construction Airborne Noise Impact near Lee Nam Road Barging Point, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
AKPS	Educational	64-71	70	Yes

Note: Bold figures denote exceedance of relevant noise criteria. Cumulative impact from the construction of LET Station has been included.

Table 3.19: Unmitigated Construction Airborne Noise Impact near Chung Hom Shan Magazine Site, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
CHK	Residential	50-63	75	No

Cumulative Impacts

The currently undergoing redevelopment at Ocean Park is in the vicinity of the proposed OCP station. All infrastructure construction works for the redevelopment at Ocean Park are expected to be completed by the time of the commencement of this Project. No cumulative impact from this project is anticipated.

Part of the currently undergoing project “Drainage Improvement in Northern Hong Kong Island – Hong Kong West Drainage” is in the vicinity of Admiralty and Telegraphy Bay close to the works area of this Project. There are works for DSD’s Harbour Area Treatment Scheme Stage 2A project are in the vicinity of Telegraph Bay Barging Point. Cumulative impact from these projects would be assessed.

Another project, Shatin to Central Link (SCL), is also proposed by the Project Proponent. The enabling works of SCL at Admiralty will be carried out under SIL(E) at the time of the ADM construction. In the construction noise assessment of this Project, all plants to be involved in the ADM construction have been included. Hence it is considered that the cumulative impact from the SCL project had been taken into account in the assessment.

The cumulative construction impact from the modification of the Wong Chuk Hang Nullah has already been included in the construction noise assessment as the works is considered as part of the Project.

Essential Public Infrastructure Works (EPIWs)

Apart from the construction of tunnelling works, station and the viaduct, there are Essential Public Infrastructure Works (EPIWs) to enhance the accessibility of the station for public uses. Cumulative impact due to EPIWs had been taken into account in the assessment to evaluate the worse scenario. These EPIWs include:

¡ Widening of Heung Yip Road and associated road improvement works;

¡ Public Transport Interchange (PTI) underneath Wong Chuk Hang (WCH) Station;

¡ Footbridge connecting to Heung Yip Road and WCH Road; and

¡ Footbridge connecting to Ap Lei Chau Estate.

Other Construction Works

Re-provisioning of a temporary PTI next to Grandview Garden at WCH would be carried out concurrently with the major construction works. Cumulative impact due to the works had been taken into account in the assessment to evaluate the worst scenario.

3.4.1.4 Mitigation of Adverse Environmental Impact

In order to reduce the excessive noise impacts at the affected NSRs during normal daytime working hours, mitigation measures such as adopting quiet powered mechanical equipment, movable noise barriers and temporary noise barriers are recommended. It is practical to specify the total SWL of all plant to be used on site. The Contractors do not have to use specific items of quiet plant adopted in this assessment. They can choose to use other types of quiet plant which have the same total SWL or a lower SWL, to meet their needs. The mitigated plant inventories are shown in Appendix 3.3.

Adoption of Quieter PME

In order to reduce the excessive noise impacts at the affected NSRs during normal daytime working hours, quieter PME are recommended. The quieter PME adopted in the assessment were taken from the BS5228: Part 1:2009 and are presented in Table 3.20. It should be noted that the silenced PME selected for assessment can be found in Hong Kong.

Table 3.20: Quieter PME Recommended for Adoption during Construction Phase

PME	Power rating/size, weight	Reference	SWL, dB(A)
Handheld breaker	35kg	BS D2-10	110
Hydraulic breaker, Excavator mounted	52kW	BS D8-12	106
Concrete lorry mixer	5m3	BS D6-35	100
Concrete pump	100kW	BS D6-36	106
Mobile crane	62kW	BS D7-114	101
Vibratory Poker, handheld	2kW each poker	BS D6-20	102
Bulldozer	218kW	BS D3-72	111
Excavator	45kW	BS D3-35	106
Dump truck	50t	BS D9-39	103
Vibratory roller	9kW	BS D3-115	102
Asphalt paver	-	BS D8-24	101

Whilst quieter PME are listed, the Contractor may be able to obtain particular models of plant that are quieter than the PMEs given in GW-TM.

Use of Movable Noise Barrier

The use of movable barrier for certain PME can further alleviate the construction noise impacts. In general, a 5 dB(A) reduction for movable PME and 10 dB(A) for stationary PME can be achieved depending on the actual design of the movable noise barrier. The Contractor shall be responsible for design of the movable noise barrier with due consideration given to the size of the PME and the requirement for intercepting the line of sight between the NSRs and PME. Barrier material with surface mass in excess of 7 kg/m² is recommended to achieve the predicted screening effect. A schematic configuration of movable noise barrier is shown in Figure 3.22a.

Use of Noise Enclosure/ Acoustic Shed

The use of noise enclosure or acoustic shed is to cover stationary PME such as air compressor and concrete pump. With the adoption of the noise enclosure, the PME could be completely screened, and noise reduction of 15 dB(A) can be achieved according to the GW-TM. A schematic configuration of full noise enclosure for PME is shown in Figure 3.23.

Use of Silencer

To reduce noise emission from the ventilation fans, silencers are also recommended to be used in fan ventilation system to attenuate noise generated during fan operation to achieve a noise reduction of 15dB(A). The Contractor shall be responsible for selection of appropriate silencers for the ventilation fans.

Use of Noise Insulating Fabric

Noise insulating fabric (the Fabric) can also be adopted for certain PME (e.g. drill rig, pilling auger etc). The Fabric should be lapped such that there are no openings or gaps on the joints. Technical data from manufacturers state that by using the Fabric, a noise reduction of over 10 dB(A) can be achieved on noise level (Reference has been made to Tsim Sha Tsui Station Northern Subway EIA Report, 2008). As a conservative approach, a noise reduction of 10 dB(A) for the PME lapped with the Fabric was assumed.

A summary of the assumed noise reduction effects achieved by the movable noise barrier, noise enclosure, silencer and fabric for certain items of PME are presented in Table 3.21.

Table 3.21: Noise Mitigation Measures for Certain PME during Construction Phase

PME	Mitigation Measures Proposed	Noise Reduction, dB(A)
Air compressor	Noise enclosure	15
Compactor, vibratory	Movable noise barrier	5
Concrete pump	Noise enclosure	15
Drill rig, rotary type (diesel)	Noise insulating fabric	10
Grout pump	Movable noise barrier	10
Handheld breaker	Movable noise barrier	10
Ventilation fan	Silencer	15
Water pump	Movable noise barrier	10
Welder/Generator, portable	Movable noise barrier	10
Mobile crane	Movable noise barrier	5
Excavator	Movable noise barrier	5
Lorry with crane/ grab	Movable noise barrier	5
Concrete lorry mixer	Movable noise barrier	5
Saw, circular, wood	Movable noise barrier	10
Prestress Jack	Movable noise barrier	5
Dump truck	Movable noise barrier	5
Bulldozer	Movable noise barrier	5
Burster	Movable noise barrier	5
Rock drill	Noise insulating fabric	10
Pile rig	Noise insulating fabric	10
Rock crusher	Noise enclosure	15

Note: No mitigation measures are applied for works below decking.

Good Site Practice

Although the noise mitigation effects are not easily quantifiable and the benefits may vary with site conditions and operating conditions, the good site practices listed below should be followed during each phase of construction:

¡ Only well-maintained plant should be operated on-site and plant should be serviced regularly during the construction programme

¡ Silencers or mufflers on construction equipment should be utilized and should be properly maintained during the construction programme

¡ Mobile plant, if any, should be sited as far from NSRs as possible

¡ Machines and plant (such as trucks) that may be in intermittent use should be shut down between work periods or should be throttled down to a minimum

¡ Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from the nearby NSRs

¡ Material stockpiles and other structures should be effectively utilized, wherever practicable, in screening noise from on-site construction activities.

3.4.1.5 Mitigated Construction Airborne Noise Impact

With the implementation of all the above-mentioned mitigation measures, the total SWLs of each activity were predicted, and are presented in Appendix 3.3. Table 3.22 to Table 3.30 present the mitigated noise levels during normal daytime working hours at NSRs.

Table 3.22: Mitigated Construction Airborne Noise Impact near Admiralty Station, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
NLH	Residential	60-73	75	No
RP	Residential	60-75	75	No
PH	Residential	67-75	75	No

Table 3.23: Mitigated Construction Airborne Noise Impact near Nam Fung Portal, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
GP	Residential	48-67	75	No
SFE1	Residential	51-69	75	No
UGA	Educational	49-67	70	No
YSM1	Convalescent Home	56-71	75	No

Table 3.24: Mitigated Construction Airborne Noise Impact near Ocean Park Station, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SW2	Residential	58-69	75	No
SW4	Residential	45-72	75	No
PC4	Residential	55-71	75	No

Table 3.25: Mitigated Construction Airborne Noise Impact near Wong Chuk Hang Station and Depot, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
PC1	Residential	60-73	75	No
PC2	Residential	61-72	75	No
SIS1	Educational	57-71	70	Yes
SIS2	Planned educational	58-74	70	Yes
CPS	Educational	60-76	70	Yes
GG	Residential	58-73	75	No
SMH1	Home for the elderly	61-75	75	No
SMH2	Home for the elderly	61-72	75	No

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.26: Mitigated Construction Airborne Noise Impact near Wong Chuk Hang Nullah and Aberdeen Channel, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
TWGH1	Convalescent Home	58-75	75	No
TWGH2	Convalescent Home	53-71	75	No
HSS1	Educational	45-77	70	Yes
HSS2	Educational	45-76	70	Yes
HSS4	Educational	52-71	70	Yes
OC1	Residential	48-66	75	No
OC2	Residential	48-66	75	No
SWT1	Residential	61-73	75	No
SWT2	Residential	46-75	75	No
SWT3	Residential	46-72	75	No
TLC1	Educational	45-65	70	No
YOK	Educational	45-67	70	No
YOC4	Residential	59-70	75	No
SMB	Residential	47-68	75	No

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.27: Mitigated Construction Airborne Noise Impact near Lei Tung Station and Entrances, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
AKPS	Educational	56-65	70	No
CMA	Nursery	66-67	75	No
LTE2	Residential	60-67	75	No
LDN	Nursery	66-67	75	No
LTE4	Residential	60-67	75	No
NEC	Home for the elderly	67-69	75	No
LTE5	Residential	61-69	75	No
SPC	Educational	59-60	70	No
LMCC	Educational	60-61	70	No
YCB	Residential	64-79	75	Yes
SFB	Residential	72-75	75	No
HFB	Residential	66-69	75	No
LFB	Residential	61-68	75	No

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.28: Mitigated Construction Airborne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SOH5	Residential	49-82	75	Yes
SOH6	Residential	50-81	75	Yes
SOH7	Residential	52-76	75	Yes
SOH8	Residential	50-78	75	Yes
PBPS	Educational	57-74	70	Yes
HKPS	Educational	60-61	70	No

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.29: Mitigated Construction Airborne Noise Impact near Telegraph Bay Barging Point, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
AT1	Residential	67-72	75	No

Table 3.30: Mitigated Construction Airborne Noise Impact near Lee Nam Road Barging Point, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Construction Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
AKPS	Educational	56-65	70	No

With the implementation of the above-mentioned mitigation measures, the construction noise levels at most of the representative NSRs are predicted to comply with the noise standards stipulated in the EIAO-TM. Residual construction noise impacts are however predicted at various locations and will be discussed in Section 3.4.1.7.

3.4.1.6 Cumulative Construction Airborne Noise Impact

As mentioned in Section 3.4.1.3, there are concurrent projects, Hong Kong West Drainage Tunnel (HKWDT) and HATS Stage 2A located within the assessment area of the proposed railway, cumulative assessment has been carried out and presented in the following tables. References have been made from the HKWDT EIA and HATS Stage 2A EIA.

According to the HKWDT EIA, there are three intake shafts located within the study area of the proposed SIL(E) namely, MA14, B2 and W3, in the vicinity of Admiralty. The maximum mitigated sound power level of the construction of the intake shafts was predicted as 105 dB(A) (ref: Table C1c of Appendix C of HKWDT EIA). The cumulative impact from this concurrent project is presented in Table 3.31.

Table 3.31 Cumulative Construction Airborne Noise Impact in the vicinity of Admiralty

NSR ID	Intake shaft	SWL of Construction of Intake shaft, dB(A)	Slant Distance to Intake shaft, m	Distance Correction, dB(A)	*Overall SPL of Construction of Intake Shafts, dB(A)	Max. SPL in this EIA, dB(A)	Cumulative SPL, dB(A)	Exceedance of Noise Criteria?
NLH	MA14	105	475	-62	55	73	73	No
	B2	105	258	-56
	W3	105	284	-57
RP	MA14	105	478	-62	59	75	75	No
	B2	105	259	-56
	W3	105	121	-50
PH	MA14	105	836	-66	51	75	75	No
	B2	105	628	-64
	W3	105	310	-58

Note(*): Facade correction of +3 dB(A) has been included

A footbridge across South Horizon Drive near Yi Nam Road junction which is an EPIW proposed to be built during the construction of SOH Station. The noise contribution of the EPIW has been already taken into account to assess the cumulative impact. The comparison of the construction noise impact between cases with and without the EPIW is presented in Table 3.32. It is found that the noise exceedance at NSR PBPS is mainly due to the contribution from the EPIW.

Table 3.32: Cumulative Construction Airborne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A)

NSR ID	Construction Noise Level without EPIW, dB(A)	Construction Noise Level with EPIW, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SOH5	49-82	49-82	75	Yes
SOH6	50-81	50-81	75	Yes
SOH7	52-76	52-76	75	Yes
SOH8	50-78	50-78	75	Yes
PBPS	43-68	57-74	70	Yes

Note: Bold figures denote exceedance of relevant noise criteria.

According to the HATS Stage 2A EIA, the identified NSR in the vicinity of Telegraph Bay Barging Point is same to this EIA i.e. NSR AT1. The maximum mitigated sound pressure level is 71 dB(A) (ref: Appendix 4.9 of HATS 2A EIA) which has already taken into account the cumulative impact from the HKWDT. The cumulative impact from this concurrent project is presented in Table 3.33.

Table 3.33 Cumulative Construction Airborne Noise Impact in the vicinity of Telegraph Bay Barging Point

NSR ID	Maximum SPL in this EIA, dB(A)	Maximum SPL in HATS 2A EIA, dB(A)	Overall SPL, dB(A)	Exceedance of Noise Criteria?
AT1	72	71	75	No

Based on Table 3.31 to Table 3.33 above, cumulative impact from the concurrent projects have been assessed, exceedance of relevant noise criteria is predicted at NSR PBPS and further mitigation measures would be proposed subject to the liaison with the EPIW works contractor.

3.4.1.7 Evaluation of Residual Construction Airborne Noise Impact

With the implementation of the above-mentioned mitigation measures, the construction noise levels at most of the representative NSRs are predicted to comply with the noise standards stipulated in the EIAO-TM. Residual construction noise impacts are predicted at NSRs near Wong Chuk Hang Depot, Wong Chuk Hang Nullah, Ap Lei Chau Main Street entrance i.e. Entrance A of LET Station and South Horizons. A summary table below (Table 3.34) shows the range of exceedance and the duration of residual impacts.

Table 3.34: Summary of Residual Impact

NSR ID	Land Use	Range of exceedance, dB(A)	Duration of residual impact, weeks		No. of floors exceeded noise criteria	No. of dwellings/ classrooms per floor	Assumed no. of residents per dwelling	Population affected
			1 to 4 dB(A)	≥ 5 dB(A)
Wong Chuk Hang Depot
SIS1	Educational	1	4	0	10	5	-	-
SIS2	Planned educational	1-4	22	0	15	not available	-	-
CPS	Educational	1-6	26	4	5	10 (G/F – 2/F) 8 (3/F – 4/F)	-	-
Wong Chuk Hang Nullah
HSS1	Educational	2-7	4	34	4	1	-	-
HSS2	Educational	2-6	4	34	4	4	-	-
HSS4	Educational	1	4	0	4	4	-	-
Entrance A of Lei Tung Station
YCB	Residential	2-4	46	0	4	1	3	12
South Horizons
SOH5	Residential	2-7	2	10	5	4	3	60
SOH6	Residential	1-6	22	10	5	4	3	60
SOH7	Residential	1	10	0	1	4	3	12
SOH8	Residential	2-3	12	0	3	4	3	36
Total Affected Population								180

Residual impacts predicted mainly due to the limited separation distance between the NSRs and the works area. The feasibility of providing further mitigation measures and site constraints are discussed below.

Wong Chuk Hang Depot

Due to massive construction works including drill and blast, excavation and piling activities along the perimeter of the Wong Chuk Hang depot and more stringent criterion for the educational use, residual impact is anticipated. Due to the truck movement logistics during the drill and blast and site formation activities, the location of the crusher, which is one of the dominant noise sources, will potentially be sited west of the depot area otherwise energy and time wastage in handling of spoil via long routing to the site exit would be anticipated. Moreover piling has to be carried out along the site boundary mitigation measures such as movable noise barrier would not be feasible due to limited space otherwise more area of the existing traffic lane has to be occupied. The noise mitigation measures have already been proposed include:

¡ Adoption of quiet PME;

¡ Noise insulating fabric;

¡ Acoustic enclosures;

¡ Moveable noise barriers; and

¡ The rock crusher will also be provided with noise enclosure subject to the design of the Contractor, a typical layout of the rock crushing facility is given in Figure 2.7.

Having taken into account the above, it was considered that all direct mitigation measures have been exhausted and the construction noise impact at this works area has been minimized.

Wong Chuk Hang Nullah

A large number of piling construction works are involved along the Wong Chuk Hang Nullah where site space is limited and massive mitigation measures like large full enclosure is deemed not feasible. The noise mitigation measures have already been proposed include:

¡ Adoption of quiet PME;

¡ Noise insulating fabric; and

¡ Moveable noise barriers.

It was considered that all direct mitigation measures have been exhausted and the construction noise impact at this works area has been minimized.

Lei Tung Station Entrance A

Due to the noise sensitive receivers are in close proximity to the works area (~12m) and have a direct line of sight to the works area, residual impact is anticipated. The measures have already been proposed to minimize the noise impact include:

¡ Adoption of quiet PME;

¡ Silencer;

¡ Noise insulating fabric; and

¡ Moveable noise barriers.

To further mitigate the residual noise impact from construction, the feasibility of installing additional mitigation measure in terms of a large full noise enclosure around the works area has also been considered. However, implementing a large noise enclosure would cause the following inconvenience and environmental concern:

¡ The large noise enclosure structure would in some case reduce the available space for the pedestrian access.

¡ The erection and dismantling of the noise enclosure would result in longer construction period and additional noise impact.

¡ Massive arrangement may lead to safety problem in case of emergency.

¡ Visual impact to the adjacent residential receivers at lower floors.

¡ Impact to the existing structure of the adjacent buildings.

South Horizons Station

Due to the noise sensitive receivers are in close proximity to the works area (~11m) and have a direct line of sight to the works area, residual impact is anticipated. Moreover, Yi Nam Road act as a local distributor road to serve the South Horizons area, closure of whole Yi Nam Road is not feasible. The construction of the SOH station has been designed in stages at different works areas with temporary decking over to allow traffic flow at the surface while underground works could still be carried out. The use of decking could effectively mitigate the noise from works underground. The measures have already been proposed to minimize the noise impact include:

¡ Quieter construction method: (i) press-in piling method for pipe pile walls and (ii) using road ripper for road breaking;

¡ Adoption of quiet PME;

¡ Silencer;

¡ Noise insulating fabric;

¡ Moveable noise barriers;

¡ Movable noise barriers have also been proposed for rock breaking on slope using hand-held breakers. Subject to the design of the Contractor, the movable noise barriers would be easy to assemble and disassemble and weight could be put at the base of the noise barrier to prevent tip over (a schematic drawing is shown in Figure 3.22b); and

¡ Use of decking to mitigate the noise from underground works at certain construction phase.

To further mitigate the residual noise impact from construction, the feasibility of installing additional mitigation measure in terms of a large full noise enclosure around the works areas has also been considered. However, implementing a large noise enclosure would cause the following inconvenience and environmental concern:

¡ The large noise enclosure structure would in some case reduce the available space for the diverted vehicles and footpaths for pedestrians.

¡ Relocations of the noise enclosure would be required according to the shift of the works area. The erection and dismantling of the noise enclosure would result in longer construction period and additional noise impact.

¡ Massive arrangement may lead to safety problem in case of emergency.

¡ Visual impact to both the pedestrians and the residential receivers at lower floors.

¡ Impact to the existing structure of South Horizons basement and encroachment onto the private lot.

Having taken into account the above, it was considered that all direct mitigation measures have been exhausted and the construction noise impact at this works area has been minimized.

3.4.1.8 Indirect Technical Remedies

Residual noise impacts have been minimised through exhausting all practicable direct noise mitigation measures including the use of quieter plant, temporary / movable noise barriers, noise enclosure/acoustic shed, silencers, noise insulating fabric, noise insulating cover, acoustic enclosure, decking over the excavation area / shaft and re-scheduling the sequence of works as far as practicable. Having reviewed the site constraints and nature of works to be undertaken at various works areas, it is considered that all practicable mitigation measures have been exhausted and residual impacts have been minimised.

Because of the close proximity to the NSRs, further direct mitigation measures would not be practicable in eliminating all construction noise exceedance. Indirect Technical Remedies (ITR) is therefore considered for minimizing the construction noise impacts.

It should be noted that the use of ITR as a mitigation measure is neither a requirement stipulated under Annex 13 of the EIAO-TM nor the EIA Study Brief. The provision of ITR is the initiative of the Project Proponent in view of the noise disturbance associated with the construction of the SIL(E). ITR would generally require the consideration to upgrade the glazing if necessary for the noise sensitive facades exposed to excessive residual noise impact. The provision of air-conditioning would also be considered for those affected dwellings.

Consideration will be given to make reference to the previous approved EIA of WIL for the eligibility criteria proposed for qualifying NSRs for ITR which would be dependent on the severity of the residual noise impact and duration of exceedance after implementing all practical direct mitigation measures.

3.4.2 Ground-borne Noise

3.4.2.1 Identification of Noise Source

Potential ground-borne noise impact during the construction phase could be caused by drill and blast and cut and cover activities for tunnelling works, and the use of PMEs such as the hydraulic breakers, hand-held breakers and rock drill for other construction activities.

3.4.2.2 Assessment Methodology

The schematic for the ground-borne noise prediction model is discussed in the following paragraphs. This generalised prediction model will be adopted for used in both construction and operational ground-borne noise assessment. The prediction methodology for assessing the ground-borne noise impact from construction equipment is detailed as follows:

Approach for Construction Equipment

The method used to predict construction ground-borne noise from the use of PME construction equipment is shown below.

LA = Lv,rms + C dist + C damping + BCF + BVR + CTN
LA	A-weighted Ground-borne noise level at NSR, ref: 20 µ-Pascal
C dist	Distance attenuation
C damping	Soil damping loss across the geological media
Lv,rms	Vibration velocity (in RMS) of a PME at a reference distance
BCF	Vibration coupling loss factor between the soil and the foundation, relative level
BVR	Building vibration reduction or amplification within a structure from the foundation to the occupied areas, relative level
CTN	Conversion from floor and wall vibration to noise, 10^-8 m/s or 10^-6 in/s to 20 µ-Pascal

Reference Vibration Sources

The vibratory velocities for typical construction equipment with reference to the approved Kowloon Southern Link EIA (Register No.: AEIAR-083/2005) and are listed in Table 3.35 to Table 3.36.

Table 3.35: Reference Vibration Level Based on Measurements

Construction Equipment	Construction Site	Vibration (RMS) at Reference Distance of 5.5m from source
Drilling Rig	Salisbury Road Overrun Tunnel	0.536 mm/s
Hydraulic Breaker	TST site	0.298 mm/s
Handheld Breaker	New World Centre site	0.279 mm/s
Source: Appendix 7-1 of Kowloon Southern Link EIA Report

Table 3.36: Source Vibration Velocity of Octave Band Frequency for Hydraulic Breaker

Octave Band Frequency (Hz)	16	31.5	63	125	250	500
Source Vibration Velocity, mm/s	0.0589	0.0682	0.0620	0.0503	0.0623	0.1209
Source: Appendix 7-1 of Kowloon Southern Link EIA Report

Soil Damping Loss

Vibration wave propagation in ground will decay with distance due to damping loss within the soil. The reduction in vibration amplitude can be estimated based on the Transportation Noise Reference Book^[1].

The rate of decay will depend on vibration frequency, the soil loss factor (η), the wave speed c of the soil and the distance R between sources to the NSR. The wave propagation properties of typical soil are shown in the Table 3.37.

Table 3.37: Wave Propagation Properties of Soil

Ground Type	Longitudinal Wave Speed c, ms^-1	Loss Factor, η	Density, g/cm^3
Soil	1500	0.5	1.7
Rock	3500	0.01	2.65

For this noise impact assessment, no damping attenuation (i.e. 0 dB(A)) will be applied to propagation in rock.

Building Coupling Loss (BCF)

Interaction between the building foundation and the soil will cause some reduction in the vibration level. The correction factors shown in Table 3.38 which are based on the lower adjustment factor presented in Saurenman (1982)^[2], for a more conservative assessment.

Table 3.38: Adjustment Factor for Building Coupling Loss (BCF)

Building Type	Limit	Building Coupling Loss (dB)
		16	31.5	63	125	250	500
Large Masonry Building on Pile	Lower	-6	-7	-11	-13	-14	-12
Large Masonry Building on Spread Footings	Lower	-12	-14	-14	-13	-11	-10
1 to 2 Storey Residential	Lower	-4	-5	-5	-4	-3	-1
Building Foundation on Rock Layer		0	0	0	0	0	0

Building Vibration Response (BVR)

Building Vibration Response (BVR) consists of two factors, namely Building Structure Attenuation (BSA) and Building Structure Resonance (BSR). Vibration generally reduces in level as it propagates through a building. On the other hand, amplification occurs due to building element resonance. Table 3.39 below shows the adjustment factors based on Saurenman (1982)^[3].

Table 3.39: Adjustment Factor for Building Structure Attenuation (BSA)

Floor level above grade	Floor Attenuation Factor (dB)
	16	31.5	63	125	250	500
1	2	2	3	3	3	4
2	2	2	2	3	3	4
3	2	2	2	2	3	3
4 to 5	1	1	2	2	3	3
6 to 7	1	1	1	2	3	3
8 to 9	1	1	1	1	2	3
10 and above	1	1	1	1	2	3

Since ground-borne vibration level will be the highest on the lower level of a building, a conservative building structure attenuation factor of 2 dB per octave band (Table 3.40) is proposed for the SIL(E) study.

Table 3.40: Building Structure Attenuation (BSA) for SIL(E) Study

Octave Band Centre Frequency (Hz)	16	31.5	63	125	250	500
Floor Attenuation Factor (dB)	2	2	2	2	2	2

Ground vibration level will increase within the building due to building element resonance. The amount of amplification will depend on building construction method. For typical concrete based building construction, a 6 dB increase per octave band (Table 3.41) will be adopted for the SIL(E) study in accordance with the FTA Handbook recommendation.

Table 3.41: Building Structure Resonance (BSR) for SIL(E) Study

Octave Band Centre Frequency (Hz)	16	31.5	63	125	250	500
Floor and Wall Resonance (dB)	6	6	6	6	6	6

Conversion from Vibration to Noise (CTN)

The level of radiated noise inside a room will depend on the average vibration of the room surfaces, the radiation efficiency of the surfaces and the amount of absorption inside the room.

Based on the conservation of power principle, the reverberant sound field inside the room can be approximated by the following equation:

Reverberant Sound Pressure Level LA (dBA) = Lv (VdB ref 1 m in/s) + CTN Equation 3.4‑1 CTN = Krad + A-weighting Correction Equation 3.4‑2 where
Krad	Adjustment to account for conversion from vibration to sound pressure level including accounting for the amount of acoustical absorption inside the room

For typical residential bedroom with nominal acoustical absorption treatment, the following factors (Table 3.42) are used for this study:

Table 3.42: Room Correction Factors

Octave Band Centre Frequency (Hz)	16	31.5	63	125	250	500
Krad (dB)	0	0	0	0	0	0
A weighting	-56.7	-39.4	-26.2	-16.1	-8.6	-3.2
CTN(for vibration)	-56.7	-39.4	-26.2	-16.1	-8.6	-3.2
For Lv vibration level reference to 1 m in/s

Multiple Vibration Sources

The ground-borne noise levels from the construction plant will be summed logarithmically in accordance with standard acoustic principles to obtain the total ground-borne noise level.

Cumulative Ground-borne Noise Impact

As discussed in Section 3.4.1.3, there is a concurrent project in the vicinity of Admiralty, HKWDT, would be carried out during the tunnelling works of the Project. Potential cumulative ground-borne noise impacts due to concurrent project would be discussed in Section 3.4.2.4.

3.4.2.3 Prediction and Evaluation of Environmental Impact

Detailed assessments have been conducted for three construction equipment (hydraulic breaker, hand-held breaker and rock drill), for tunnelling works including drill & blast along ADM and LET Stations and cut & cover works along ADM Station, Nam Fung Portal, Sham Wan Tower and SOH Station, the results are summarised in Table 3.43 to Table 3.47 below. The detailed assessment results were shown in Appendix 3.5.

Table 3.43: Unmitigated Construction Ground-borne Noise Impact near Admiralty Station, L_{eq (30mins)} dB(A)

NSR ID	Usage	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SLH	Hotel	61	65	No
RP	Residential	46	65	No
NLH	Hostel	41	65	No
GOV	Residential	40	65	No
ILS	Educational	42	60	No
CIS	Educational	43	60	No

Table 3.44 Unmitigated Construction Ground-borne Noise Impact near Nam Fung Portal, L_{eq (30mins)} dB(A)

NSR ID	Usage	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SPSS	Educational	53	60	No

Table 3.45 Unmitigated Construction Ground-borne Noise Impact near Sham Wan Tower, L_{eq (30mins)} dB(A)

NSR ID	Usage	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SWT1	Residential	50	65	No

Table 3.46: Unmitigated Construction Ground-borne Noise Impact near Lei Tung Station, L_{eq (30mins)} dB(A)

NSR ID	Usage	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?

YOC1	Residential	64	65	No
YOC2	Residential	64	65	No
YOC4	Residential	73	65	Yes
CMA	Nursery	60	65	No
SPC	Educational	61	60	Yes
LMCC	Educational	60	60	No
LDN	Nursery	62	65	No
AKPS	Educational	60	60	No

Note: Bold figures denote exceedance of relevant noise criteria.

Table 3.47 Unmitigated Construction Ground-borne Noise Impact near South Horizons Station, L_{eq (30mins)} dB(A)

NSR ID.	Usage	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of Noise Criteria?
SOH5	Residential	62	65	No
SOH6	Residential	62	65	No
SOH7	Residential	56	65	No
SOH8	Residential	65	65	No
PBPS	Educational	49	65	No

3.4.2.4 Cumulative Construction Ground-borne Noise Impact

According to the HKWDT EIA, there is a main water tunnel transverse from Eastern Portal (near Tai Hang Road) to Western Portal (near Cyberport) via the northern part of Hong Kong Island, which found overlapping with the Study Area of this Project in Admiralty. Tunnel Boring Machine (TBM) would be adopted for the construction of tunnel, potential ground-borne noise impact from the TBM had been assessed in the HKWDT EIA. According to the ground-borne noise assessment results in the HKWDT EIA, the predicted ground-borne noise levels at all NSRs will not exceed the daytime ground-borne noise criteria with a margin of over 15 dB(A) i.e. impact noise level less than 50 dB(A).

Based on the assessment result in the vicinity of Admiralty as shown in Table 3.43, the predicted ground-borne noise levels from the SIL(E) will not exceed the daytime ground-borne noise criteria with a margin of 4 dB(A) or more. Taking into account the assessment results of the HKWDT EIA, the cumulative noise impact level from both projects would still be 4 dB(A) or more below the criteria. Hence, it could be concluded that the cumulative ground-borne noise impact from HKWDT and SIL(E) to the noise sensitive receivers would not exceed the noise criteria and no mitigation measures are required.

3.4.2.5 Mitigation of Adverse Environmental Impact

The predicted construction ground-borne noise levels will comply with the stipulated noise criteria at all NSRs, except NSRs (YOC4 and SPC) in proximity to the works area along LET Station due to the drill & blast tunnelling activity. As the quantity of PME related to ground-borne noise to be adopted for the drill & blast work activity is considered as minimal, good site practices are recommended so to minimise the adverse impact as far as possible. PME that in intermittent use should be shut down between work periods or should be throttled down to a minimum.

3.4.2.6 Evaluation of Residual Construction Ground-borne Noise Impact

Based on the construction programme of the drill & blast along YOC4 and SPC, it is likely that the duration of the exceedance would last for about three weeks for YOC4 and 8 weeks for SPC. The exceedance predicted at SPC is only 1dB(A) which shall be considered as minor residual impact. Nevertheless, implementation of good site practice, careful scheduling of works and maintaining close liaison with affected parties are recommended to minimise the impact from the tunnelling works.

3.5 Operation Phase Impact

3.5.1 Airborne Noise

3.5.1.1 Railway Noise

Identification of Noise Source

The proposed SIL(E) comprise of railway alignment from Nam Fung Portal via Ocean Park Station, Wong Chuk Hang Station, Ap Lei Chau Bridge to Ap Lei Chau as shown in Figure 3.6 to Figure 3.8.

Direct Airborne Railway Noise

Noise emissions levels are dependent on the type of rolling stock, trackform and structural design of viaduct, speed, frequency of service, etc.

The reference noise level of the revenue train to be adopted for the operational airborne noise assessment makes reference to the specification of the train. The same stock is currently operating on Kwun Tong Line. The reference noise level refers to trains running at grade on ballast track is shown in Table 3.48.

Table 3.48 : Reference Train Noise Level

Reference Train speed, kph	Reference distance from track, m	Maximum Noise Level Lmax, dB(A)
80	25	78

Structure Re-radiated Railway Noise

Structure re-radiated noise from the viaduct originates from vibration generated by the wheel and track interaction. In order to attenuate the vibration and so to reduce the airborne structure re-radiated noise, low vibration trackform, Type 1a or other similar resilient baseplate trackform would be adopted.

A correction factor of +4 dB(A)[4] is proposed to be adopted in this assessment to account for structure re-radiated noise from the viaduct structure and potential noise increase due to trains running on slab track instead of on ballast track.

Tunnel Portal Effect

Apart from the direct airborne railway noise, the structure-borne noise re-radiated from the viaduct originates from vibration generated by the wheel and track interaction, the sound generated inside the tunnel will reverberate within the tunnel and exits at the portals of the tunnel. This tunnel portal effect at Nam Fung Tunnel Portal and Lei Tung Tunnel portal could potentially contribute to the overall railway noise impact at the noise sensitive receivers with line-of-sight and in proximity of the portals.

For the Lei Tung Tunnel portal, the closest NSR with line-of-sight to it is Ocean Court (OC) which is located about 270m from the portal. In view of the long separation, the tunnel portal effect from this portal to the NSR is considered to be insignificant. NSR Sham Wan Towers do not has direct line-of-sight to the tunnel portal but located at about 60m from the portal. Potential tunnel portal effect to this NSR may be anticipated.

For the Nam Fung Portal (at the ex-Canadian Hospital site near Nam Fung Path), the closest NSR with line-of-sight to it is TWGH Yeung Shing Memorial Long Stay Care Home (NSR YSM1) which is located at about 50m from the portal. Potential tunnel portal effect to this NSR may be anticipated.

Assessment Methodology

The airborne noise prediction methodology proposed for the SIL(E) noise impact assessment is generally based on the approved methodologies for the West Rail, East Rail Extensions and Sheung Shui to Lok Ma Chau Spur Line EIA studies.

Direct Airborne Railway Noise

Direct Airborne Railway Noise will be predicted using the equation below:

LAX,direct at NSR= LAX (V) + Cspeed + Cdistance + Cangle - Cbarrier + Cstr + Cdet + Cpx + Cfacade
	where
	LAX direct at NSR	predicted Sound Exposure Level at NSR
	LAX (V)	Sound Exposure Level for the train at reference distance and speed
	C speed	correction due to speed
	C distance	correction due to distance
	C angle	correction for angle of view of rail line as perceived from NSR
	C barrier	correction due to barrier/ enclosure
	C str	correction for structure re-radiated noise
	C det	correction for deterioration in rail and rolling stock condition
	C px	correction for points and crossings on track
	C facade	correction for façade reflection at NSR

For railway noise prediction, the railway alignment visible from the NSR will be divided into segments such that the variation of noise expected within each track segment will be less than 2 dB(A).

Sound exposure level - L_max Relationship

The Sound Exposure Level (L_AX (V)), for a given train speed V, is calculated by integrating the theoretical time history of train rolling noise with dipole directivity^[5]. This procedure has taken into account the length of the train and the type of track and track support system for each track segment. The following equation will be used to convert the maximum A-weighted noise level (L_A,max at NSR) of the passing train to the sound exposure level (L_AX (V)) at the NSR location.

LAX (V) = LA,max (V) + 10 log10(l/V) - 10 log10[4D/(4D^2+1)+2tan^-1(1/2D)] + 10.5
	where
	LA,max (V)	Maximum train noise level at speed V, dB(A)
	V	speed of train, kph
	D	d/l
	d	slant distance from the nearside track of the segment to the NSR (measured perpendicularly), m
	l	length of train, m

Propagation

The prediction model assumes a continuous line source located at the rail alignment. The source will be positioned at an “effective source height” of 0.9m above the railhead level for Electric Multiple Unit (EMU) in this assessment study.

Correction Terms

Speed Correction

Speed correction will be calculated using the equation below which makes reference to the West Rail EIA. The train speed profile along the proposed SIL(E) is shown in Appendix 3.6.

C speed = K log10 (V / Vref)
	where
	V	speed of train, kph
	Vref	reference speed
	K	=20 for LAX, =30 for LAmax

Distance Correction

For L_AX prediction, the distance correction for a line source propagation is given by the equation below.

C distance = -10 log10 (d / dref )
	where
	d	slant distance from track (measured perpendicularly), m
	dref	reference distance

For L_Amax prediction, the distance correction for a line source propagation is given by the equation below.

C distance = -K log10 (d / dref )
	where
	d	slant distance from track, m
	dref	reference distance
	K	= 10 (d ≤ train length), =20 (d > train length)

Angle of View Correction

The Sound Exposure Level for rail pass by will depend on the angle subtended by the rail alignment at the NSR. The angle of view effect will be corrected using the equation below.

C angle = 10 log10 (q /180)
	where
	q	Angle of view

Barrier Correction

Barrier correction will be calculated using the Kurze and Andersons’ approximation of the Maekawa chart and is shown in the equation below. This expression is based on a practical maximum barrier attenuation limit of 21 dB(A).

C barrier = min{ 21, (5 + 20 log10 [(2πN)^1/2 / tanh (2πN)^1/2 ] – PL(N)) } + Creflect
	where
	N	Fresnel Number = 2 δ / λ
	δ	Path length difference between direct and diffracted sound paths.
	λ	Wavelength of sound in air.
	PL(N)	Correction to account for the differences for attenuation between line source and point source. PL(N) is a function of the Fresnel Number N will be determined using the procedure developed by Beranek[6].
	Creflect	Correction for reflective barrier effect. = 0 for absorptive barrier = -4 for reflective barrier at least 1m above the railhead.[7]

Structure Re-radiated Correction (C_str)

A structure re-radiated correction of +4 dB(A) will be adopted in noise prediction to account for structure re-radiated noise from the viaduct structure and potential noise increase due to trains running on slab track instead of on ballast track.

Correction for deterioration in rail and rolling stock condition (C_det)

A correction for the deterioration in rail and rolling stock condition from brand new to an operating level of +3 dB(A) will be adopted in noise prediction.

Point and Crossing Correction (C_px)

There will be an increase in noise level when wheels traverse a point or a crossing. A correction of +7 dB(A) is proposed for each point and crossing along the rail alignment. Location of the crossing along the viaduct section is shown in Figure 3.7 which is found east of the proposed Wong Chuk Hang Depot.

Façade Correction (C _facade)

A façade correction of +2.5 dB(A) will be adopted for noise prediction. This correction is based on recommendation of Calculation of Railway Noise (UK Department of Transport, 1995).

Conversion to L_{Aeq 30mins}

The Sound Exposure Level (L_AX) at a particular NSR will be converted into the continuous equivalent sound pressure level L_Aeq, total using the equations below for each train type.

LA eq,T = LAX -10 log10 T LA eq, total = Leq,T + 10 log10N
	where
	LAX	LAX at NSR (direct + re-radiated)
	T	Assessment period, T = 24 hours or 30 minutes expressed in seconds
	N	number of trains pass-by within the assessment period

Summation of Contribution by all Segments

The total noise level at the NSR is the total contribution from all segments during the assessment period.

Prediction and Evaluation of Environmental Impact

In order to minimize the potential airborne railway noise impacts arises from the viaduct section of the Project, 2m high parapet with absorptive material along the viaduct at two sides are proposed as the base design scheme. A typical section diagram of the viaduct and the location of the 2m high parapet are shown in Figure 3.24.

The alignment will be in form of an enclosed concrete box structure through the ex-Canadian Hospital Site. The extent of the box structure is shown in Figure 2.1.3 and Appendix 3.2d.

For the purpose of predicting the worst case scenario, the railway noise impact assessment has based on the MTRCL service parameter for the ultimate weekday design condition. The design parameters for the ultimate condition are shown in Table 3.49. The following design parameters are used in the operation airborne noise study:

Table 3.49: Revenue Train Service Operation Detail (Ultimate Weekly)

Time Period	Frequency /direction
Peak Hour Headway
Morning (0730 ~ 0930 hrs)	2.1 mins
Evening (1700 ~ 2000 hrs)	2.3 mins
Off-peak Hour Headway
Early morning (0600 ~ 0730 hrs)	4 to 8 mins
Daytime (0930 ~ 1700 hrs)	3 to 4 mins
Late evening (2000 ~ 0130 hrs)	5 to 10 mins
Total Number of Train Trips
Daytime and Evening Time (0700 to 2300 hrs)	330 EMUs
Night time (2300 to 0700 hrs)	32 EMUs

Train Type: MTRCL K-Stock

Train Configuration: 3 cars, total length of 68m

Train Frequency: Day and Evening Period - 15 trains per direction per 30 mins

Night Period - 8 trains per direction per 30 mins

Train Speed: Train Speed Profile along the proposed SIL(E) (Refer to Appendix 3.6)

Vertical Profile: Vertical Profile along the proposed SIL(E) (Refer to Appendix 3.6)

As information regarding the type and layout of developments at the two G/IC zoned sites i.e. ex-Canadian Hospital site and the bus depot adjacent to the OCP Station and the layout of the residential development at the R(A) site above WCH Depot is not available or confirmed during the time of preparation of this report, the noise assessment has been carried out in two scenarios. One Scenario, namely Scenario for Existing NSRs, aims to present the noise mitigation measures required for existing noise sensitive uses only assuming no development in the R(A) site and two G/IC sites yet. Another Scenario, namely Scenario for Existing and Planned NSRs, aims to present the required changes in noise mitigation measures, in comparing with the Scenario for Existing NSRs, where noise sensitive uses in the R(A) site and two G/IC sites have been taken into account.

Railway Noise Impact: Scenario for Existing NSRs

According to Section 3.4.1.3(vi)(c) of the EIA Study Brief, noise level in L_{eq (30mins)}, L_{eq (24 hr)} and L_max during the day and at night at the selected NSRs shall be calculated and presented. The potential noise impacts on the NSRs due to operation of the viaduct section of SIL(E) are summarised below with the unmitigated predicted noise levels given in Table 3.50 to Table 3.52. In this unmitigated scenario, absorptive type of parapet of about 2m high is applied to whole viaduct section. A sample calculation of airborne railway noise is shown in Appendix 3.7 and the detailed breakdown of noise levels at each NSRs attributed to viaduct section is shown in Appendix 3.8.

Table 3.50: Unmitigated Railway Noise during Daytime and Evening Time (0700-2300)

NSR ID	Floor	ASR	Predicted Noise Level		Railway Noise Criteria, Leq (30mins), dB(A)	Exceedance of Noise Criteria?	Affected Floors
			Leq (30mins), dB(A)	Lmax, dB(A)
WCHH2	1/F-5/F	C	57-58	67-69	70	No	-
BC	G/F-2/F	C	56	67-68	70	No	-
YSM1	1/F-6/F	C	60-66	77-83	70	No	-
SW4	G/F-1/F	C	59	76	70	No	-
PC3	1/F-4/F	B	55-58	72-74	65	No	-
PC4	1/F-4/F	B	56-58	73-75	65	No	-
TWY	G/F	B	60	77	65	No	-
SMH1	G/F-2/F	B	65-67	81-83	65	Yes	1/F-2/F
TWGH1	1/F-5/F	B	70-74	84-88	65	Yes	1/F-5/F
TWGH2	1/F-5/F	B	65-68	81-85	65	Yes	3/F-5/F
HSS1	G/F-3/F	C	74	88-89	70	Yes	G/F-3/F
HSS2	G/F-3/F	B	69-70	86-88	65	Yes	G/F-3/F
HSS3	G/F	B	67	83	65	Yes	G/F
HSS4	G/F-3/F	C	64-67	80-83	70	No	-
OC1	1/F-31/F	C	58-62	65-71	70	No	-
OC2	1/F-31/F	C	55-61	65-70	70	No	-
SWT2	1/F-44/F	C	61-65	73-79	70	No	-
SWT3	1/F-44/F	C	62-64	73-78	70	No	-
Total No. of Affected Floors							15

Notes: Bold figure denotes exceedance of relevant noise criteria

HSS1 and HSS2 represent two different facades of the same building

SWT2 and SWT3 represent two different facades of the same building

Table 3.51: Unmitigated Railway Noise during Night Time (2300-0700)

NSR ID	Floor	ASR	Predicted Noise Level		Railway Noise Criteria		Exceedance of Noise Criteria?	Affected Floors
			Leq (30mins), dB(A)	Lmax, dB(A)	Leq(30mins), dB(A)	Lmax, dB(A)
WCHH2	1/F-5/F	C	54-55	67-69	60	85	No	-
BC	G/F-2/F	C	53-54	67-68	60	85	No	-
YSM1	1/F-6/F	C	57-63	77-83	60	85	Yes	4/F-6/F
SW4	G/F-1/F	C	56	76	60	85	No	-
PC3	1/F-4/F	B	52-55	72-74	55	85	No	-
PC4	1/F-4/F	B	53-55	73-75	55	85	No	-
SMH1	G/F-2/F	B	62-64	81-83	55	85	Yes	G/F-2/F
TWGH1	1/F-5/F	B	68-71	84-88	55	85	Yes	1/F-5/F
TWGH2	1/F-5/F	B	62-65	81-85	55	85	Yes	1/F-5/F
OC1	1/F-31/F	C	55-60	65-71	60	85	No	-
OC2	1/F-31/F	C	53-58	65-70	60	85	No	-
SWT2	1/F-44/F	C	58-62	73-79	60	85	Yes	1/F-13/F
SWT3	1/F-44/F	C	59-62	73-78	60	85	Yes	2/F-22/F
Total No. of Affected Floors								51

Notes: Bold figure denotes exceedance of relevant noise criteria

SWT2 and SWT3 represent two different facades of the same building

Table 3.52: Unmitigated Railway Noise in L_{eq (24hrs)}

NSR ID	Floor	ASR	Predicted Noise Level, Leq (24hrs) dB(A)
WCHH2	1/F-5/F	C	54-55
BC	1/F-5/F	C	53
YSM1	1/F-5/F	C	57-63
SW4	G/F-1/F	C	56
PC3	1/F-4/F	B	52-55
PC4	1/F-4/F	B	53-55
TWY	G/F	B	57
SMH1	G/F-2/F	B	62-64
TWGH1	1/F-5/F	B	67-71
TWGH2	1/F-5/F	B	62-65
HSS1	G/F-3/F	C	71
HSS2	G/F-3/F	B	66-67
HSS3	G/F	B	64
HSS4	G/F-3/F	C	61-64
OC1	1/F-31/F	C	55-59
OC2	1/F-31/F	C	52-58
SWT2	1/F-44/F	C	58-62
SWT3	1/F-44/F	C	59-61

Mitigation of Adverse Environmental Impact

Table 3.50 and Table 3.51 have indicated that exceedance of relevant noise criteria are predicted at existing NSRs including YSM1, PC4, SMH1, TWGH1, TWGH2, HSS1, HSS2, HSS3, SWT2 and SWT3, hence direct mitigation measures should be proposed to minimise the noise impact. According to the Section 6.1, Annex 13 of EIAO-TM, direct mitigation measures as listed below should be considered:

a. alternative siting

b. screening by noise tolerant buildings

c. treatment of source

d. alternative alignment

e. noise barrier/enclosure

Noise mitigation measures starting from direct ones were evaluated. When all practicable at-source mitigation measures have been exhausted, at-receiver mitigation measures are considered in terms of modification of layout plan and setback requirements for the planned NSRs.

In view of practicability, the erection of noise barrier/ semi-enclosure along the viaduct sections are effective mitigation measures in tackling the railway noise impact to sensitive receivers. The selection of trackform with necessary vibration attenuation could also be a form of mitigation measures to reduce the airborne structure re-radiated noise. The basic type of vibration mitigation trackform to be adopted in the viaduct section of the alignment is a resilient baseplate trackform, namely Type 1a (Details of the trackform could be found in Appendix 3.13).

Viaduct sections from the Nam Fung Portal, along Wong Chuk Hang Nullah and Ap Lei Chau Bridge in Aberdeen Channel are recommended to erect noise barrier/ semi-enclosure, in addition to the 2m high absorptive parapet along the whole viaduct section, to alleviate the railway noise impact for existing sensitive uses. The locations of noise barriers/ semi-enclosure are tabulated in Table 3.53 below. Figure 3.25 to Figure 3.27 show the location of the proposed noise barriers/ semi-enclosure.

Table 3.53: Proposed Location of Noise Barriers/ Enclosure for Existing Uses

Track Direction	Chain-age	Location	Type of Noise Mitigation Measures	Height, m	Length, m	Figure
Up Track (From South Horizons to Admiralty)	13530 – 13620	TWGH Yeung Shing Memorial Long Stay Care Home	Semi-enclosure covering nearest track	6	90	Fig 3.25
	15530 – 15580	Sham Wan Towers	Semi-enclosure covering both tracks with opening along northern side	6	50	Fig 3.27
Down Track (From Admiralty to South Horizons)	14660 – 15195	Wong Chuk Hang Nullah	Semi-enclosure covering the nearest track only	6	535	Fig 3.27
	15530 – 15580	Sham Wan Towers	Semi-enclosure covering both tracks with opening along northern side	6	50	Fig 3.27

As mentioned in Section 3.5.1.1, NSR YSM1 may be affected by the tunnel portal noise as it is located near the portal south of the ex-Canadian Hospital site at Nam Fung Path (about 50m). Taking into consideration of the proposed 90m long semi-enclosure at the portal, the line of sight to the portal from the NSR could be blocked and hence the potential tunnel portal effect is anticipated to be minimal. NSR Wong Chuk Hang San Wai (SW4) which is located below the viaduct connecting the portal. The potential tunnel portal effect to the NSR hence is also expected to be minimal. Another NSR Beaconsfield Court (BC) also has line-of-sight to this portal. As it is located more than 150m from the portal and tunnel portal effect would not be expected.

For the Lei Tung Tunnel portal, NSR Sham Wan Towers (SWT3) may be affected by the tunnel portal noise as it is located near the tunnel portal (about 60m) although it does not has direct line-of-sight to the tunnel portal. Taking into consideration of the proposed 50m long semi-enclosure at the portal, the potential tunnel portal effect could be screened off completely and hence tunnel portal effect would not be expected to this NSR. In view of long separation between NSR Ocean Court (OC) and the portal, which is about 270m, tunnel portal effect is considered to be insignificant to this NSR.

With the erection of noise barrier/ enclosure along the viaduct sections, the mitigated railway noise impact to the noise sensitive receivers is summarised in Table 3.54 below. A sample calculation of railway noise with mitigation measures implemented is shown in Appendix 3.9a and the detailed noise level of each floor is shown in Appendix 3.10a.

Table 3.54: Mitigated Railway Noise during Daytime and Night Time

NSR ID	Relevant Railway Noise Criteria			Mitigated Noise Level			Exceedance of Noise Criteria?
	Daytime, Leq (30mins) dB(A)	Night time, Leq (30mins) dB(A)	Lmax, dB(A)	Daytime, Leq (30mins) dB(A)	Night time, Leq (30mins) dB(A)	Lmax, dB(A)
YSM1	70	60	85	55-63	52-60	69-77	No
SMH1	65	55	85	54-56	51-53	68-70	No
TWGH1	65	55	85	55-58	52-55	69-71	No
TWGH2	65	55	85	50-51	48-49	67-68	No
HSS1*	70	-	-	68-69	-	-	No
HSS2*	70	-	-	53-54	-	-	No
HSS3*	70	-	-	50	-	-	No
SWT2	70	60	85	57-62	55-59	72-76	No
SWT3	70	60	85	59-62	56-59	72-75	No

Notes: * denotes no sensitive uses at HSS1, HSS2 and HSS3 were assumed during night time

With the erection of noise barrier/ semi-enclosure proposed along the viaduct section as shown in Figure 3.25 to Figure 3.27, no further exceedances of railway noise criteria are found at the existing NSRs. Hence, the recommended mitigation measures are considered effective in alleviating the noise impact to existing receivers. A total of 56 floors of existing residential buildings (including 5 floors during daytime and 51 floors during night-time) will benefit from the noise mitigation measures.

Railway Noise Impact: Scenario for Existing and Planned NSRs

The noise impact assessment of this Scenario focuses on the noise sensitive uses in the R(A) site above WCH Depot and two G/IC sites i.e. ex-Canadian Hospital site and the bus depot adjacent to the OCP Station and the required changes in the noise mitigation measures proposed for Scenario for Existing NSRs such that the noise impact at these sensitive receivers could comply with the relevant noise criteria.

Assessment points for the planned sensitive uses in the R(A) and G/IC sites have been selected and the locations are shown in Figure 3.28 – Figure 3.29. It is assumed that these locations are representing the worst affected facades for the planned sensitive uses in terms of airborne railway noise impact.

As the planning parameter and development details of the R(A) site are not available at the time of preparing this EIA, an approach of showing the noise level plateau off has been adopted for determining the number storeys to be assessed for the future development above the WCH Depot. The purpose of this approach is to ensure the height (or number of floors) above the site which is worst affected by railway noise has been considered in the assessment and also the necessary mitigation measures, if required. Hence the number of floors has been assessed for the site do not imply any building height for the future development.

On the other hand, the allowed maximum height for development at the ex-Canadian Hospital site is +50 mPD and 4-storey high above the bus depot G/IC site as given by Planning Department, these parameters have been adopted in the assessment.

WCH station is designed with a podium cover and thus the planned NSRs above the WCH depot do not have direct line of sight to the tracks within the station. This assumption has been made in the assessment.

The potential noise impacts on these NSRs due to operation of the viaduct section of SIL(E) with Scenario for Existing NSRs mitigation measures are summarised below in Table 3.55 to Table 3.57. The detailed noise levels at each NSR attributed to viaduct section are shown in Appendix 3.10a.

Table 3.55: Railway Noise during Daytime (0700-2300), with Scenario for Existing NSRs mitigation measures

NSR ID	*Floor	ASR	Predicted Noise Level		Railway Noise Criteria, Leq (30mins) dB(A)	Exceedance of Noise Criteria?
			Leq (30mins), dB(A)	Lmax, dB(A)
EX1	L1-L3	C	69-71	86-87	70	Yes
OCP2	1/F-4/F	C	56-61	71-76	70	No
OCP3	1/F-4/F	B	58-62	71-75	65	Yes
WCH1	1/F-30/F	B	62-66	80-83	65	Yes
WCH2	1/F-30/F	B	56-60	73-83	65	No
WCH3	1/F-30/F	B	62-65	73-83	65	No

Notes: (*) Assumed floor levels for indicative purpose only. Actual number of floors subject to future approved design.

Bold figure denotes exceedance of relevant noise criteria

Table 3.56: Railway Noise during Night time (2300-0700), with Scenario for Existing NSRs mitigation measures

NSR ID	*Floor	ASR	Predicted Noise Level		Railway Noise Criteria		Exceedance of Noise Criteria?
			Leq (30mins) dB(A)	Lmax, dB(A)	Leq (30mins), dB(A)	Lmax, dB(A)
EX1	L1-L3	C	67-68	86-87	60	85	Yes
OCP2	1/F-4/F	C	53-58	71-76	60	85	Yes
OCP3	1/F-4/F	B	55-59	71-75	55	85	Yes
WCH1	1/F-30/F	B	59-64	80-83	55	85	Yes
WCH2	1/F-30/F	B	53-57	73-83	55	85	Yes
WCH3	1/F-30/F	B	59-62	73-83	55	85	Yes

Notes: (*) Assumed floor levels for indicative purpose only. Actual number of floors subject to future approved design.

Bold figure denotes exceedance of relevant noise criteria

Table 3.57: Railway Noise in L_{eq (24hrs)} dB(A), with Scenario for Existing NSRs mitigation measures

NSR ID	*Floor	ASR	Predicted Noise Level, Leq (24hrs) dB(A)
EX1	L1-L3	C	66-68
OCP2	1/F-4/F	C	53-58
OCP3	1/F-4/F	B	55-59
WCH1	1/F-30/F	B	59-63
WCH2	1/F-30/F	B	53-57
WCH3	1/F-30/F	B	59-62

Notes: (*) Assumed floor levels for indicative purpose only. Actual number of floors subject to future approved design.

Further Mitigation Measures for Scenario for Existing and Planned NSRs

Table 3.55 and Table 3.56 have indicated that exceedance of relevant noise criteria are predicted at the planned NSRs including EX1, OCP1, OCP3, WCH1, WCH2 and WCH3, hence further direct mitigation measures should be proposed to minimise the noise impact for the Scenario for Existing and Planned NSRs.

Viaduct sections from Nam Fung Portal to OCP Station and from OCP Station to WCH Station are recommended to erect additional noise barrier/semi-enclosure to alleviate the railway noise impact for the planned sensitive uses. The locations of the additional noise barriers/semi-enclosure are tabulated in Table 3.58 below. Figure 3.28 to Figure 3.30 show the location of the proposed additional noise barriers/semi-enclosure. Schematic cross-sections of the proposed noise barrier/ semi-enclosures are shown in Figure 3.31 to Figure 3.33.

Table 3.58: Proposed Location of Additional Noise Barriers/ Enclosures for Planned Uses

Track Direction	Chain-age	Location	Type of Noise Mitigation Measures	Height, m	Length, m	Figure
Up Track (From South Horizons to Admiralty)	13530 – 13620	TWGH Yeung Shing Memorial Long Stay Care Home	Semi-enclosure covering both tracks with opening along southern side	6	90	Fig 3.28
	13930 – 14100	West of Ocean Park G/IC Site	Semi-enclosure covering both tracks with opening along southern side	6	170	Fig 3.29
	14210 – 14400	East of Wong Chuk Hang Residential Zone	Semi-enclosure covering all tracks of the viaducts with opening along northern side	6	190	Fig 3.29
	14660 – 14720	West of Wong Chuk Hang Residential Zone	Semi-enclosure covering both tracks with opening along northern side	6	60	Fig 3.30
Down Track (From Admiralty to South Horizons)	13530 – 13620	TWGH Yeung Shing Memorial Long Stay Care Home	Semi-enclosure covering both tracks with opening along southern side	6	90	Fig 3.28
	13930 – 14100	West of Ocean Park G/IC Site	Semi-enclosure covering both tracks with opening along southern side	6	170	Fig 3.29
	14020 – 14100	Police School	Vertical Barrier	2.2m above parapet	80	Fig 3.29
	14210 – 14400	East of Wong Chuk Hang Residential Zone	Semi-enclosure covering all tracks of the viaducts with opening along northern side	6	190	Fig 3.29
	14660 – 14720	West of Wong Chuk Hang Residential Zone	Semi-enclosure covering both tracks with opening along northern side	6	60	Fig 3.30
	14660 – 14720	West of Wong Chuk Hang Residential Zone	Vertical Barrier	2.4 m above parapet	60	Fig 3.30

Notes: OCP station will be upgraded to fully decking design to block the direct line of sight to the tracks within the station from the planned NSRs at the G/IC site next to the station should the development at the site is noise sensitive use.

With erection of the additional noise barriers / semi-enclosures along the viaduct sections, the mitigated railway noise impact to the noise sensitive receivers is summarised in Table 3.59 below. A sample calculation of railway noise with mitigation measures implemented is shown in Appendix 3.9b and the detailed noise level of each floor is shown in Appendix 3.10b.

Table 3.59: Mitigated Railway Noise during Daytime and Night Time

NSR ID	Relevant Railway Noise Criteria			Mitigated Noise Level			Exceedance of Noise Criteria?
	Daytime, Leq (30mins) dB(A)	Night time, Leq (30mins) dB(A)	Lmax, dB(A)	Daytime, Leq (30mins) dB(A)	Night time, Leq (30mins) dB(A)	Lmax, dB(A)
EX1	70	60	85	57-58	54-55	72-75	No
OCP2	70	60	85	56-61	53-58	71-76	No
OCP3	65	55	85	54-58	51-55	67-70	No
WCH1	65	55	85	55-57	52-54	69-71	No
WCH2	65	55	85	55-58	52-55	71-74	No
WCH3	65	55	85	55-58	52-55	72-75	No

With the erection of the additional noise barriers/semi-enclosures proposed along the viaduct section as shown in Figure 3.28 to Figure 3.30, no further exceedances of railway noise criteria are found at the planned NSRs. Hence, the recommended mitigation measures are considered effective in alleviating the noise impact to planned receivers.

Evaluation of Residual Impact

G/IC sites at ex-Canadian Hospital site and Citybus depot

As the assessment for those planned noise sensitive receivers are based on representative assessment points, further review of the proposed noise mitigation measures shall be carried out after the confirmation of the design layout of the developments in the two G/IC sites. In view of this, the viaduct structure would allow further installation of noise barrier or enclosure at the later commissioning stage, if required. In addition, further mitigation measures if necessary would also be allowed in the OCP station to block the direct line of sight from the planned NSRs within the G/IC site to the tracks with the station. Nevertheless, in case the future development in the G/IC site is not noise sensitive, no direct noise mitigation measures would be considered. The additional noise barriers/enclosures where required would be provided before the occupation of the planned NSRs.

WCH R(A) site

Similar to the two G/IC sites, the assessment for the planned noise sensitive receivers are based on representative assessment points and heights, further review of the proposed noise mitigation measures shall be carried out after the confirmation of the design layout of the residential development above the WCH Depot before population intake. In view of this, the viaduct structure would allow further installation of noise barrier or enclosure at the later commissioning stage, if required. Nevertheless, in case the future development in the R(A) site is not noise sensitive, no direct noise mitigation measures would be considered. The additional noise barriers/enclosures where required would be provided before the occupation of the planned NSRs.

In view of the above, no further exceedances of railway noise criteria are found at the representative NSRs. Hence, no residual impact is anticipated.

3.5.1.2 Fixed Plant Noise

Identification of Noise Source

Ventilation Systems

Noise from fixed plant for the proposed SIL(E) would mainly be associated with tunnel ventilation and cooling systems for stations and Wong Chuk Hang Depot. According to the preliminary design information, major fixed plant noise is attributed to the following sources and summarised in Table 3.60 and shown in Figure 3.34 to Figure 3.43: -

¡ Ventilation systems and fixed plant at the five stations;

¡ Ventilation systems and fixed plant at Wong Chuk Hang Depot; and

¡ Ventilation systems and fixed plant at Hong Kong Park, Nam Fung Portal / Ventilation Building, Lee Wing Street Plant Building and Lee Nam Road Plant Building.

Table 3.60: Summary of Fixed Plant Noise Sources

Location	Fixed Noise Source	Number of Fixed Plant	Opening ID	Direction of Facing*	Figure
ADM Station	Block A (SIL)	4	ADM-A1 to A4	All	3.34.2
	Block B (SIL)	5	ADM-B1 to B5	All	3.34.2
	Block C (SIL)	5	ADM-C1 to C5	All	3.34.2
	Block D (SIL)	4	ADM-D1 to D4	All	3.34.3
	Block E (SIL)	10	ADM-E1 to E10	All	3.34.3
	Block F (SIL)	4	ADM-F1 to F4	All	3.34.4
	Block G (SIL)	1	ADM-G1	All	3.34.4
	Block N (SIL)	1	ADM-N1	upward	3.34.4
Hong Kong Park	Stair Pressurization Air Duct	1	HKP01	SE	3.35.1
	Exhaust From Transformer Rooms	1	HKP02	NE	3.35.1
	Fresh Air Intake for Transformer Room	1	HKP03	NE	3.35.2
	SEVS	1	HKP04	NW	3.35.1
	Vent Shaft (SIL)	1	HKP05	NW	3.35.1
Nam Fung Portal	Staircase Pressurization Fan Room	1	NAM01	SE	3.36.1
	Pressure Relief Duct	1	NAM02	SE	3.36.1
	Air Plenum (V08)	1	NAM03	SE	3.36.2
	Air Plenum (V07)	1	NAM04	SE	3.36.2
	Air Plenum (V09)	1	NAM05	SE	3.36.2
	BEVS (V01) (Roof Level)	1	NAM06	SE	3.36.2
	HEC RMU Room (Ground Floor)	1	NAM07	SE	3.36.2
	BEVS (V01) (Ground Level)	1	NAM08	SE	3.36.2
	HEC RMU Room (Ground Floor)	1	NAM09	NE	3.36.3
	HEC TX Room (Ground Floor)	2	NAM10, NAM11	NE	3.36.3
	SSVS (V02)	1	NAM12	SW	3.36.3
OCP Station	Louver for Smoke Extraction	1	OCP1	S	3.37.1
	Louvers for Fresh Air Intake/ Exhaust	1	OCP2	S	3.37.1
	Exhaust Air Louvre Opening at High Level	3	OCP3 to OCP5	S	3.37.1
	Fresh Air Louvre at High Level	2	OCP6, OCP8	S	3.37.1
	Exhaust Air Louvre Opening at Low Level	1	OCP7	S	3.37.1
	Exhaust Air Louvre	2	OCP9, OCP10	S	3.37.1
	Fresh Air Louvre at Low Level	1	OCP11	S	3.37.1
	Smoke Discharge	1	OCP12	W	3.37.2
	Fresh Air Intake Louvre Opening at Full Height	1	OCP13	W	3.37.2
	Louvre for Fresh Air Intake & Exhaust	1	OCP14	E	3.37.2
WCH Station	Ventilation shaft for WCH Station	7	WCH1 to WCH7	All	3.38.1-3
	TEF	2	WCH8, WCH9	E, W	3.38.4-5
WCH Depot	Ventilation shaft for air intake	1	WCD-FA01	All	3.39.1
		1	WCD-FA02	All	3.39.1
		1	WCD-FA03	All	3.39.1
	Ventilation shaft for Smoke Extraction & Normal Exhaust	1	WCD-SE01	All	3.39.1
		1	WCD-SE02	All	3.39.1
		1	WCD-SE03	All	3.39.1
		1	WCD-EA01	E	3.39.1
	Ventilation Opening (depot façade)	11	WCD1 to WCD11	E, SW	3.39.2-3
LET Station (Entrance B)	SPF Room (3rd Floor)	1	LET01, LET02	N, W	3.40.1
	BEVS (3rd Floor)	1	LET03	W	3.40.1
	TSVS (3rd Floor)	1	LET04	E	3.40.1
	FEVS (3rd Floor)	1	LET05	S	3.40.1
	Natural Air Make-up (3rd Floor)	1	LET06, LET07	E, S	3.40.1
	TEVS (2nd Floor)	1	LET08	W	3.40.2
	SSVS (2nd Floor)	1	LET09	E	3.40.2
	TEVS (1st Floor)	1	LET10	W	3.40.2
	SSVS (1st Floor)	1	LET11	E	3.40.2
LET Station (Entrance A)	VOID (Roof Floor)	1	LET12	NW	3.40.4
	Plant Room (1^st Floor)	1	LET13	NW	3.40.3
TVF near Sham Wan Tower	TVF (Ground Level)	2	LET14, LET15	NW	3.41.2
SOH Station (Entrance A)	Air Intake/ Exhaust ductings with louvre openings	1	LNR01a-d	All	3.42.1
(SOH Plant Building)	Louvre at Ground Level	2	LNR02, LNR03	NW	3.42.4
	Louvre at Ground Level	2	LNR04, LNR05	NW	3.42.4
	Louvre at Ground Level	1	LNR06	NW	3.42.4
	Louvre at Roof Level	2	LNR07, LNR08	SE	3.42.4
	UPS (First Level)	1	LNR09	SE	3.42.4
	Louvre at First Level (Fireman Lift Shaft)	2	LNR10, LNR11	SE	3.42.4
	BEVS (First Level)	1	LNR12	SE	3.42.4
	Staircase Pressurization REF IEF Duct (First Level)	1	LNR13	SE	3.42.4
	SSVS (First Level)	1	LNR14	SE	3.42.4
	Louvre at First Level	2	LNR15, LNR16	SW	3.42.5
	Louvre at Ground Level	1	LNR17	SW	3.42.5
	Louvre at First Level	1	LNR18	NE	3.42.5
	Louvre at Ground Level	1	LNR19	NE	3.42.5
SOH Station (Entrance C)	Louvre opening	1	LNR20	SW	3.42.1
Lee Wing Street Plant Building	TVF	6	LWB01 to LWB06	N, E, S	3.43.1
	Louvre (3^rd Floor)	1	LWB07	S	3.43.2
	Louvre (2^nd Floor)	1	LWB08	S	3.43.2
	Louvre (1^st Floor)	1	LWB09	S	3.43.2
	Louvre (Ground Floor)	1	LWB10	S	3.43.2
	Chiller Plant Room (3^rd Floor)	1	LWB11	S	3.43.2
	Tunnel ESC Control Room (2^nd Floor)	1	LWB12	S	3.43.2
	PER (HV & TX) (1^st Floor)	1	LWB13	S	3.43.2
	HEC RMU (Ground Floor)	1	LWB14	S	3.43.2
	HEC TX (Ground Floor)	3	LWB15 to LWB17	S	3.43.2
	Tunnel ESC Control Room (2^nd Floor)	1	LWB18	E	3.43.3
	Tunnel Air Compressor & Receiver Room (2^nd Floor)	1	LWB19	E	3.43.3
	PER (HV & TX)	1	LWB20	E	3.43.3
	TVS (4^th Floor)	1	LWB21	N	3.43.4
	TVS (4^th Floor)	1	LWB22	N	3.43.4

Notes (*): N – North, NE – Northeast, E – East, SE – Southeast, S – South, SW – Southwest, W – West, NW – Northwest, All – All direction

Depot Activities in Wong Chuk Hang Depot

Fixed plant noise would also associate with the depot activities. The noise generating activities in Wong Chuk Hang Depot include: -

¡ Wheel lathes works;

¡ Train washing; and

¡ Plants operation within workshops and plant rooms

According to the design information, the depot would be provided with a continuous concrete podium cover and concrete side walls, without openings other than depot entrances and ventilation outlets. Behind the concrete wall are mainly the offices, workshops, plant rooms and store rooms. This design serves double sealing of the noise of the depot activities from coming out the depot. Hence it is considered that the potential fixed plant noise impact from depot to the NSRs is minimal.

Assessment Methodology

Ventilation Systems

In the absence of any detailed information and noise specification for the proposed fixed plant, the maximum permissible noise emission levels at the shaft/ exhaust openings would be determined instead for future detailed design of the fixed plant.

For the assessment of noise from the fixed plant, the maximum permissible sound power levels (Max SWLs) of the identified fixed noise sources were determined by adopting standard acoustics principles. The following formula was used for calculating the Max SWLs of the fixed plant:

SPL = Max SWL – DC + FC

where

SPL: Sound Pressure Level in dB(A)

Max SWL: Maximum Permissible Sound Power Level in dB(A)

DC: Distance Attenuation in dB(A) = 20 log D + 8 [where D is the distance in m]

FC: Façade Correction in dB(A) = +3 dB(A)

It is assumed that all the fixed plant within the same location would be operated at the same time as worst case scenario. If the noise sources do not fall within the view angle of the representative NSR under assessment or are completely blocked by the residential blocks/ buildings, it is assumed that these noise sources are insignificant to that NSR and would be excluded from calculation. While the sources fall within the view angle of the NSR but with no direct line of sight to the opening, a 10 dB(A) attenuation would be applied.

If exceedance to the noise criteria is found for one NSR, the initial SWL of the dominant sources to that NSR would be gradually lowered until the corrected SPL at that NSR meets the acceptable level. The process would be repeated for other representative NSRs with exceedance in the noise criteria until all corrected SPLs at the representative NSRs meet the noise criteria. The maximum allowable SWLs of the ventilation shafts will then be predicted.

For planned residential receivers at the Wong Chuk Hang Depot site and the potential sensitive uses at the two G/IC sites, the information of the development layout is not finalised or available at the time of preparation of this report. A design oriented approach has been adopted for the assessment.

No corrections have been applied for tonality, intermittency or impulsiveness. If the noise exhibits any of these characteristics during the operation of the plant, the noise limit should be reduced in accordance with the recommendation given in Section 3.3 of IND-TM.

A design target of “noise criteria – 6 dB(A)” i.e. ANL – 5 – 6 dB(A), are applied for NSRs near Admiralty Station due to the cumulative impact from the fixed plants of existing Admiralty Station and the planned Shatin to Central Link (SCL).

A design target of “noise criteria – 3 dB(A)” i.e. ANL – 5 – 3 dB(A), are applied for NSRs at the following locations to account for the cumulative impact from nearby planned fixed plants:

¡ Hong Kong Park Shaft due to the cumulative impact from the fixed plants of the planned SCL; and

¡ Wong Chuk Hang Station and Depot due to the cumulative impact from the fixed plants of the future development above the Depot.

Prediction and Evaluation of Environmental Impact

Ventilation Systems

Based on the methodology mentioned above, the maximum allowable SWLs of the ventilation shafts during daytime and night-time are predicted and as shown in Table 3.61 below. Sample calculation of fixed plant noise assessment is shown in Appendix 3.11.

Table 3.61: Maximum SWLs of the Fixed Plant

Location	Fixed Noise Source	Opening ID	Maximum SWL during daytime, dB(A)	Maximum SWL during night time, dB(A)
ADM Station	Block A (SIL)	ADM-A1 to A4	97	87
	Block B (SIL)	ADM-B1 to B5	96	86
	Block C (SIL)	ADM-C1 to C5	96	86
	Block D (SIL)	ADM-D1 to D4	96	86
	Block E (SIL)	ADM-E1 to E10	97	87
	Block F (SIL)	ADM-F1 to F4	97	87
	Block G (SIL)	ADM-G1	97	87
	Block N (SIL)	ADM-N1	97	87
Hong Kong Park	Stair Pressurization Air Duct	HKP01	96	86
	Exhaust From Transformer Rooms	HKP02	96	86
	Fresh Air Intake for Transformer Room	HKP03	96	86
	SEVS	HKP04	96	86
	Vent Shaft (SIL)	HKP05	96	86
Nam Fung Portal	Staircase Pressurization Fan Room	NAM01	84	74
	Pressure Relief Duct	NAM02	84	74
	Air Plenum (V08)	NAM03	93	83
	Air Plenum (V07)	NAM04	93	83
	Air Plenum (V09)	NAM05	93	83
	BEVS (V01) (Roof Level)	NAM06	93	83
	HEC RMU Room (Ground Floor)	NAM07	93	83
	BEVS (V01) (Ground Level)	NAM08	93	83
	HEC RMU Room (Ground Floor)	NAM09	84	74
	HEC TX Room (Ground Floor)	NAM10, NAM11	84	74
	SSVS (V02)	NAM12	84	74
OCP Station	Louver for Smoke Extraction	OCP1	103	93
	Louvers for Fresh Air Intake/ Exhaust	OCP2	103	93
	Exhaust Air Louvre Opening at High Level	OCP3 to OCP5	103	93
	Fresh Air Louvre at High Level	OCP6, OCP8	100	90
	Exhaust Air Louvre Opening at Low Level	OCP7	100	90
	Exhaust Air Louvre	OCP9, OCP10	100	90
	Fresh Air Louvre at Low Level	OCP11	100	90
	Smoke Discharge	OCP12	103	93
	Fresh Air Intake Louvre Opening at Full Height	OCP13	103	93
	Louvre for Fresh Air Intake & Exhaust	OCP14	103	93
WCH Station	Ventilation shaft for WCH Station	WCH1 to WCH7	(*)	(*)
	TEF	WCH8, WCH9	(*)	(*)
WCH Depot	Ventilation shaft for air intake	WCD-FA01 to FA-03	(*)	(*)
	Ventilation shaft for Smoke Extraction & Normal Exhaust	WCD-SE01 to SE03, EA01	(*)	(*)
	Ventilation Opening (depot façade)	WCD1 to WCD11	84-96	74-86
LET Station (Entrance B)	SPF Room (3rd Floor)	LET01, LET02	94	84
	BEVS (3rd Floor)	LET03	94	84
	TSVS (3rd Floor)	LET04	94	84
	FEVS (3rd Floor)	LET05	94	84
	Natural Air Make-up (3rd Floor)	LET06, LET07	94	84
	TEVS (2nd Floor)	LET08	93	83
	SSVS (2nd Floor)	LET09	93	83
	TEVS (1st Floor)	LET10	93	83
	SSVS (1st Floor)	LET11	93	83
LET Station (Entrance A)	VOID (Roof Floor)	LET12	84	74
	Plant Room (1^st Floor)	LET13	84	74
TVF near Sham Wan Tower	TVF (Ground Level)	LET14, LET15	103	93
SOH Station (Entrance A)	Air Intake/ Exhaust ductings with louvre openings	LNR01a-d	86	75
(SOH Plant Building)	Louvre at Ground Level	LNR02, LNR03	80	70
	Louvre at Ground Level	LNR04, LNR05	80	70
	Louvre at Ground Level	LNR06	80	70
	Louvre at Roof Level	LNR07, LNR08	93	83
	UPS (First Level)	LNR09	93	83
	Louvre at First Level (Fireman Lift Shaft)	LNR10, LNR11	93	83
	BEVS (First Level)	LNR12	93	83
	Staircase Pressurization REF IEF Duct (First Level)	LNR13	83	83
	SSVS (First Level)	LNR14	93	83
	Louvre at First Level	LNR15, LNR16	82	72
	Louvre at Ground Level	LNR17	82	72
	Louvre at First Level	LNR18	82	72
	Louvre at Ground Level	LNR19	82	72
SOH Station (Entrance C)	Louvre Opening	LNR20	83	73
Lee Wing Street Plant Building	TVF	LWB01 to LWB06	104	94
	Louvre (3^rd Floor)	LWB07	108	98
	Louvre (2^nd Floor)	LWB08	108	98
	Louvre (1^st Floor)	LWB09	108	98
	Louvre (Ground Floor)	LWB10	108	98
	Chiller Plant Room (3^rd Floor)	LWB11	108	98
	Tunnel ESC Control Room (2^nd Floor)	LWB12	108	98
	PER (HV & TX) (1^st Floor)	LWB13	108	98
	HEC RMU (Ground Floor)	LWB14	108	98
	HEC TX (Ground Floor)	LWB15 to LWB17	108	98
	Tunnel ESC Control Room (2^nd Floor)	LWB18	102	92
	Tunnel Air Compressor & Receiver Room (2^nd Floor)	LWB19	102	92
	PER (HV & TX)	LWB20	102	92
	TVS (4^th Floor)	LWB21	102	92
	TVS (4^th Floor)	LWB22	102	92

Notes (*): As layout of planned noise sensitive receivers has not been finalised, the assessment approach is presented in following paragraphs.

For planned residential receivers at the Wong Chuk Hang Depot site and the potential sensitive uses at the two G/IC sites, a design target approach has been derived according to the same acoustic principle. Assuming a NSR is affecting by one single opening of the ventilation system, the maximum permissible sound power levels for that opening such that the ANL – 5 dB(A) criteria could be met at the sensitive receiver at different distances are shown in Table 3.62 below.

Table 3.62: Correction Factor for Maximum SWL of the Fixed Plant

Distance from Fixed Noise Source to NSR, m	ASR of the NSR is B		ASR of the NSR is C
	Maximum SWL during daytime, dB(A)	Maximum SWL during night time, dB(A)	Maximum SWL during daytime, dB(A)	Maximum SWL during night time, dB(A)
1	65	55	70	60
5	79	69	84	74
10	85	75	90	80
15	89	79	94	84
20	91	81	96	86
25	93	83	98	88
30	95	85	100	90
40	97	87	102	92
50	99	89	104	94
60	101	91	106	96
75	103	93	108	98
100	105	95	110	100

Notes : As design target of ANL – 5 – 3 dB(A) is adopted for fixed plants of WCH Station and Depot(above podium), -3 dB(A) shall be applied to the maximum SWL.

Should the NSR is affected by more than one opening of the ventilation system, the maximum permissible sound power level at each opening shall be applied a correction factor for the cumulative effect. The values of the correction factor related to the number of openings are shown in Table 3.63 below.

Table 3.63: Correction Factor for Maximum SWL of the Fixed Plant

Number of source affecting the same NSR	Correction to Maximum SWL, dB(A)
1	0
2	-3
3	-5
4	-6
5	-7
6	-8
7	-8
8	-9
9	-10
10	-10

Fixed Plant in Wong Chuk Hang Depot

As mentioned in the above section, according to the design information, the depot would be provided with a continuous concrete podium cover and concrete side walls, without openings other than depot entrances and ventilation outlets. Behind the concrete wall are mainly the offices, workshops, plant rooms and store rooms. This design serves double sealing of the noise of the depot activities from coming out the depot. Hence it is considered that the potential fixed plant noise impact from depot to the NSRs is minimal.

Mitigation of Adverse Environmental Impact

With the fixed plant properly designed to meet the maximum SWL listed in Table 3.61, there would not be any residual impacts predicted. However, it is still recommended that the following noise reduction measures shall be considered as far as practicable during construction:

¡ Choose quieter plant such as those which have been effectively silenced.

¡ Include noise levels specification when ordering new plant (including chillier and E/M equipment).

¡ Locate fixed plant/louver away from any NSRs as far as practicable.

¡ Locate fixed plant in walled plant rooms or in specially designed enclosures.

¡ Locate noisy machines in a basement or a completely separate building.

¡ Install direct noise mitigation measures including silencers, acoustic louvers and acoustic enclosure where necessary.

¡ Develop and implement a regularly scheduled plant maintenance programme so that equipment is properly operated and serviced in order to maintain a controlled level of noise.

Evaluation of Residual Impact

With the appropriate design of fixed plant with mitigation measures to achieve the maximum SWL stated in Table 3.61, no residual impacts from the fixed plant noise is anticipated.

This design of the depot would seal the noise of the depot activities from coming out the depot and hence no residual fixed plant noise impact from depot is expected.

3.5.2 Ground-borne Noise

3.5.2.1 Identification of Noise Source

The train for SIL(E) will be of the same type as those running on the existing Kwun Tong Line (K-Stock) , but will be in a 3-car configuration with a total length of 68m.

For the purpose of predicting the worst case equivalent continuous ground-borne noise level (L_{Aeq 30mins}) as required by the EIAO, noise predictions were carried out using MTRCL service parameters for the ultimate design scenario. The following design parameters are used for the ground-borne noise study:

Train Type: MTRCL K-Stock

Configuration: 3 cars, total length of 68m

Train Frequency: Day and Evening Period - 15 trains per direction per 30 mins

Night Period - 8 trains per direction per 30 mins

Train Speed: Train Speed Profile along the proposed SIL(E) (Refer to Appendix 3.6)

Vertical Profile: Vertical Profile along the proposed SIL(E) (Refer to Appendix 3.6)

The K-Stock train was reported by MTRCL as very similar to the M-Stock train used in the existing Island Line. From a vibration generation perspective, the main difference between the two train types is the braking systems. The K-Stock trains utilise a disk brake system while the M-Stock trains utilise a cast-iron brake system. In addition, the K-Stock train is lighter than the M-Stock train and could result in lower force transmission into the tunnel structure.

In general, the use of disk braking system will reduces the wheel-rail wear and roughness^[8] and therefore results in lower source vibration level. Since the M-Stock train uses cast iron braking system, the source vibration level for the M-Stock train is expected to be on average higher than that for the K-Stock train.

The source vibration spectra (Force Density Level FDL) for the M-Stock train, previously measured^[9] for the West Island Line EIA project, are used in this assessment study and are listed in Appendix 3.12. Since the M-Stock train has higher source vibration level than the K-Stock train, the use of M-Stock train source vibration levels represents a conservative approach to the ground-borne noise assessment.

It should also be noted that the FDL spectra for the M-Stock train represents the maximum vibration level envelop for the measured data plus 2 standard deviations^[10]. Furthermore, the data was reported to have been measured with the wheels and rail in somewhat deteriorated condition. Hence the source vibration level for this assessment is relatively conservative.

3.5.2.2 Assessment Methodology

The methodology used for this EIA study is based on the ground-borne noise and vibration assessment procedure detailed in the “Transit Noise and Vibration Impact Assessment 2006” (FTA2006)^[11]. The assessment procedure based on an earlier version of this manual^[12] has been adopted by various EIA projects in HKSAR, including KCRC’s West Rail, Kowloon Southern Link and MTRCL’s West Island Line etc.

The prediction model is based on a combination of measurements and empirical formulae proposed in FTA2006 and in the Transportation Noise Reference Book (Nelson 1987)^[13], and is represented by Equation 3.5‑1 and Equation 3.5‑2 below:

Lv = LF + TM line + C building Equation 3.5‑1 LA,max = L v + CTN + Design Factor Equation 3.5‑2
	Where
	Lv	Ground-borne Vibration Level for single train pass-by (dB ref 1 min/s)
	LA,max	Maximum A-weighted Ground-borne Noise Level for single train pass-by (dB(A))
	L F	Ground-borne Force Density Level = Force Density Level for the vibration source (FDL (dB re 1 lb/in^0.5) + Adjustment for Speed + Adjustment for wheel and track condition + Track Form Attenuation (TIL) + Turnout and cross over correction factor (TOC)
	TM Line	Line Source Transfer Mobility = Track Structure Coupling Loss Factor (i.e. Tunnel Coupling Loss for underground tunnel TCF) + Spreading Loss + Soil Propagation Loss factor
	C Building	Adjustment for Building Foundation Coupling Loss (BCF) and Building Structure Attenuation (BSA) and Building Structure Resonance (BSR)
	CTN	Adjustment for converting the ground-borne vibration level for building element to A-weighted noise level inside the building
	Design Factor	Correction to account for uncertainty in the modelling parameters, including wheel/rail wear condition. A +10 dB(A) design factor is proposed due uncertainty in the inputs for the assessment.

The adjustment factors selected for the ground-borne noise study are discussed in Appendix 3.13. The Corporation will further review the Line Source Response values during the construction stage after tunnel boring.

The L_A,max ground-borne noise level represents the maximum noise level for the train pass-by event. The ground-borne noise level is converted into L_{A,eq (30mins)} noise level for comparison with the ground-borne ANL criteria using Equation 3.5‑3 below:

L_A,eq (30mins) noise level = L_A,max + 10 log (pass by duration) + Tailing Effect Correction
+ 10 log (number of pass by per 30mins period) - 32

Equation 3.5‑3

The Tailing Effect Correction account for the noise/vibration level arrived at the NSR before and after the pass-by event and is dependent on the distance and the transfer mobility between the line source and the NSR.

The assessment was carried out for each of the 1/3-octave band frequency between 12.5Hz and 500Hz to address low to mid frequency noise caused by the train pass-by event.

3.5.2.3 Prediction and Evaluation of Environmental Impact

Ground-borne noise predictions were carried out for representative NSRs located in Admiralty, Lei Tung and South Horizons. These NSRs represent the worst case scenario for the ground-borne noise assessment as these NSRs are closest to the tunnel alignment. Noise predictions were conducted for both day/evening and night periods using the target train speed profile provided by MTRCL.

The predicted ground-borne noise levels at the representative NSRs are summarised in Table 3.64 below.

Table 3.64: Operation Ground-borne Noise Prediction Results (Unmitigated)

NSR	Floor Level	Train Speed, km/h	Slant Distance^1, m	Ground-borne ANL, dB(A)		Predicted Ground-borne Noise Level ^2, 3, dB(A)			Remarks
				Day and Evening^4	Night^4	Lmax	Day and Evening^4	Night^4
Admiralty
Island Shangri-La Hotel (SLH)	4/F	55	23.6	55	45	29	19	16	Hotel tower locates above retail podium. Also included a 10 dB(A) turnout and crossing correction
Regent on the Park (RP)	1/F	80	87.9	55	45	35	23	20
Jockey Club New Life Hostel (NLH)	1/F	80	156.6	55	45	14	5	2
Island School (ILS)	G/F	80	175.2	55	n.a.	14	6	3
Carmel School (CIS)	G/F	80	162.3	55	n.a.	15	7	4
Non Departmental Quarters (GOV)	1/F	80	175.7	55	45	12	4	1
Lei Tung
Sham Wan Towers - Tower 1 (SWT1)	1/F	70	37.5	55	45	22	10	7	Residential tower locates above retail podium
Sham Wan Towers - Tower 3 (SWT2)	1/F	70	45.0	55	45	19	8	5	Residential tower locates above retail podium
Pik On House (YOC1)	1/F	55	34.6	55	45	44	33	30
Tse On House (YOC2)	1/F	55	35.8	55	45	43	32	30
Shan On House (YOC4)	1/F	55	12.2	55	45	53	42	39
Tung Yip House (LTE1)	1/F	70	61.6	55	45	46	34	31
Cheng Pon Hing Hostel for the Elderly (CPHH)	G/F	70	61.6	55	n.a.	48	36	33
Tung Hing House (LTE2)	1/F	70	65.4	55	45	45	33	30
CMA Lei Tung Child Care Centre (CMA)	G/F	70	66.8	55	n.a.	46	34	31
Lei Tung Community Hall (LTCH)	G/F	70	76.3	55	n.a.	41	29	26
Tung Mau House (LTE4)	1/F	35	56.3	55	45	43	33	31
Lei Tung Lutheran Day Nursery (LDN)	G/F	35	56.3	55	n.a.	45	35	33
Aberdeen Baptist Lui Ming Choi College (LMCC)	1/F	35	56. 0	55	n.a.	43	34	31
Lei Tung Neighbour Elderly Centre (NEC)	G/F	35	60.8	55	45	43	33	31
St Peter’s Catholic Primary School (SPC)	1/F	35	47.9	55	n.a.	47	38	35
Ap Lei Chau Kaifong Primary School (AKPS)	1/F	70	54.3	55	n.a.	50	37	35
South Horizons
Mei Cheung Court (SOH5)	1/F	35	32.0	55	45	12	3	<0	Residential tower above podium.
Mei Ka Court (SOH6)	1/F	40	8.0	55	45	57	48	45	Residential tower above podium. Included a 10 dB(A) cross over correction.
Cambridge Court (SOH7)	1/F	35	36.5	55	45	6	<0	<0	Residential tower above podium.
Dover Court (SOH8)	1/F	35	4.5	55	45	72	62	60	Residential tower above podium. Included a 10 dB(A) cross over correction.
Precious Blood Primary School (PBPS)	1/F	35	75.0	55	n.a.	2	<0	<0
Planned Future Hotel (HTL1)	1/F	35	91.5	55	45	<0	<0	<0
Note 1: - Shortest distance between nearside track and foundation/bottom of pile Note 2: - Bold figures denote exceedance of relevant noise criteria Note 3: - Predicted noise level included a 10 dB(A) safety factor Note 4: - Noise level in LA eq(30 min).

It can be shown in Table 3.64 above that the predicted ground-borne noise levels are less than the ground-borne ANL criteria for both day/evening and night-time periods, except at first floor of Dover Court, South Horizon Phase IV. At Dover Court a potential maximum ground-borne L_{Aeq 30mins} noise level of 60 dB(A) was predicted for the night time period.

The ground-borne noise exceedance at Dover Court was primarily due to relatively short distance between the track alignment and the building foundation and from additional noise generated from track crossing locate near the end of the station box. Possibility for relocating the track crossing further away from NSR was investigated by MTRCL but was technically not viable for operational reasons. The noise exceedence at Level 1 of Dover Court could be mitigated to achieve full compliance with the ground-borne ANL by the use of incline turnout (a 5 dB(A) reduction in turnout and crossing vibration) and Type 1a resilient baseplated trackform within the SOH station. This mitigation proposal has been evaluated by MTRCL and is considered to be technically feasible. The extent of the proposed mitigation measure would be applied to the track section between Chainage 16730 and 16980 and the location is shown in Figure 3.44.

Using the proposed mitigation measure, the ground-borne noise levels for NSRs near SOH Station are summarised in Table 3.65 below. A sample calculation of operation ground-borne noise assessment is presented in Appendix 3.14.

Table 3.65 Operation Ground-borne Noise Prediction Results (Mitigated)

NSR	Assessment Level	Ground-borne Noise Level, dB(A)
		Lmax	Day / Evening*	Night*
Mei Ka Court (SOH6)	1/F	42	32	30
Dover Court (SOH8)	1/F	55	46	43

Notes (*): Noise level in LA eq(30 min)

While noise exceedance was not predicted at Lei Tung or Admiralty, as a contingency measure, the currently proposed trackform can be replaced by Type 1a resilient baseplate trackform without the requirement to increase the size of the tunnel structure. Depending on actual installation and the location of the NSR, a 7 to 12 dB(A) noise level reduction could be expected from the Type 1a trackform.

Should further noise reduction is found necessary during detailed design or commissioning stage, the proposed trackform could be replaced with Type 1b resilient baseplates trackform which could provide a further 3 to 6 dB(A) noise reduction and changing of tunnel dimensions would also not be required.

The Corporation will review the need of further noise mitigation measures, if necessary, after gathering the actual Line Source Response values during the construction stage.

G/IC at Ex-Canadian Hospital Site

Ground-borne noise impact was also considered for planned NSR at the ex-Canadian Hospital site.

In considering the proposed SIL(E) is a medium-capacity railway system with the box structure on soil at the concerned section and no details for the building(s) layout and the foundation design is available for this planned NSR at the time of the EIA study, detailed ground-borne noise prediction was not carried out at this location. Nevertheless, potential ground-borne noise impact was assessed using the general vibration assessment procedure[14] as detailed in FTA2006.

The predicted ground-borne noise level would only be of the order of Leq 38 dB(A) and Lmax 50 dB(A) on the ground level. The ground-borne noise impact would likely be less than the EIAO ground-borne ANL criteria for this location using conservative assumptions such as +10dBA adjustment for efficient vibration propagation.

The assessment was carried out by assuming the foundation of the nearest NSR will be located 3m from the railway structure. It is our understanding that part of this future development would likely to be constructed above the box structure extending from the Nam Fung Tunnel. However, there will be no direct structural connection between the foundation of this future development and the railway structure due to railway protection requirement. Hence, no direct structure-borne noise and vibration transmission into the building is expected.

In addition, geological surveys conducted at this site show the rock head location is of the order of 25m below surface. Hence the whole box structure would be supported on piles. This construction method is poor for vibration energy transmission when compare with rock based tunnel.

Although no noise exceedance is expected at this site, MTRCL will continue to liaise with the owner of this site to resolve any interface issues between the two developments when more information becomes available.

3.5.2.4 Cumulative Impact at Admiralty

The existing Island Line run across the Admiralty area and the SCL under planning would also operate in the same area in addition to SIL(E). According to the results shown in Table 3.64, the predicted ground-borne noise levels at the NSRs in the area are at least 20 dB(A) below the ANL and hence no adverse cumulative impact to the existing ground-borne noise level is expected. Potential cumulative ground-borne noise impact for NSRs located in the vicinity of both SIL(E) and SCL would be addressed in the SCL EIA study.

3.5.2.5 Evaluation of Residual Impact

Based on the assessment results detailed in the previous sections, the underground rail operation can achieve compliance with the ground-borne noise level criteria at all ground-borne NSRs. No residual impact would be anticipated if inclined turnout and Type 1a resilient trackform or mitigation measures with equivalent vibration reduction characteristic were provided within the SOH station.

3.6 Environmental Monitoring and Audit

3.6.1 Construction Phase

Given residual airborne noise impact is predicted during the construction phase at Wong Chuk Hang Depot, Wong Chuk Hang Nullah, Entrance A of LET Station and SOH Station, to ensure that the nearby NSRs will not be subjected to unacceptable construction noise impact, an Environmental Monitoring and Audit (EM&A) programme is recommended. Details on the noise monitoring requirements, methodology and action plans would be described in the separated EM&A Manual.

3.6.2 Operation Phase

Prior to the operation phase of the Project, commissioning tests should be conducted to ensure compliance of both the operational airborne and ground-borne noise levels with the relevant EIAO-TM noise criteria. Details of the test requirements are provided in a stand-alone EM&A Manual.

3.7 Conclusion

3.7.1 Construction Phase

Assessments have been based on the latest information obtained, with the implementation of the mitigation measures in form of quiet plant, movable noise barrier/ enclosure and fabric, the construction noise levels at most of the representative NSRs are predicted to comply with the noise standards stipulated in the EIAO-TM. Residual construction noise impacts are predicted at NSRs near Wong Chuk Hang Depot, Wong Chuk Hang Nullah, Entrance A of LET Station and South Horizons. The last resort, ITR, would be considered at the discretion of the Project Proponent, if required.

Residual ground-borne construction noise impacts are predicted at NSRs near Lei Tung Station with a duration of about three weeks to eight weeks.

3.7.2 Operation Phase

During the operation phase, the airborne and ground-borne noise impact due to the operation of proposed SIL(E) through the tunnel and viaduct section have been predicted. The results indicated that there are noise exceedances of relevant noise criteria at NSRs. With the implementation of noise mitigation measures recommended in the form of noise barrier/ semi-enclosure for railway noise, specification of maximum sound power level of the fixed plant at stations, depot and ventilation shafts and buildings and resilient trackform for South Horizons Station, full compliance of Noise Control Ordinance and EIAO-TM criteria could be meet.

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[1] Nelson, P.M., Transportation Noise Reference Book. 1987.

[2] Saurenman, H., Nelson, J., Wilson, G. 1982, Handbook of urban Rail Noise and Vibration Control, US Department of Transportation Urban Mass Transportation Administration (Figure 8.12).

[3] Saurenman, H., Nelson, J., Wilson, G. 1982, Handbook of urban Rail Noise and Vibration Control, US Department of Transportation Urban Mass Transportation Administration (Table 8-7).

[4]Table 6.4 of Transit Noise and Vibration Impact Assessment, US Federal Transit Administration, 2006 (FTA2006)

[5]Noise Advisory Council, A Guide to the Measurement and Prediction of the Equivalent Noise Level Leq, HMSO, London (1978).

[6] Beranek, L., Noise and Vibration Control, McGraw-Hill, 1971.

[7] This is based on a noise barrier 1.5m from the train body. Reflective barrier correction for Calculation of Railway Noise (CRN), UK Department of Transport, 1995, and FTA2006 are 4.6dB(A) and 3dB(A) respectively.

[8] Crocker, M., “Handbook of Noise and Vibration Control”, Ch119, 2007

[9] By others.

[10] The 2 standard deviation value was determined from the measurements and was of the order of 4 dB or more at each 1/3 octave band frequency. The use of maximum plus 2 standard deviation as the source vibration level is, statistically, very conservative. Normally, sample mean plus or minus 2 standard deviation represent 95% of the possible value for the sample population.

[11] FTA 2006, Transit noise and vibration impact assessment, US Federal Transit Administration.

[12] FTA 1995, Transit noise and vibration impact assessment, US Federal Transit Administration.

[13] Nelson, P. 1987, Transportation Noise Reference Book, Butterworth

^[14] The assumed path for ground-borne noise transmission is as follow:

Ground-borne vibration source level : 76 dB re 1x10-6 in/sec

Track to box structure : +0 dB

Efficient Propagation : +10 dB

Ground to foundation of future building development : -10 dB assuming foundation on pile

Building Structure Resonance : +6 dB

Train pass-by on both tracks for worst case scenario : +3 dB

Vibration to A-weighted Noise : -35 dB