Section Title Page

4. Noise Impact Assessment 4-1

4.1 Introduction________________________________________________________________ 4-1

4.2 Environmental Legislation, Standards and Guidelines_______________________________ 4-1

4.3 Assessment Area, Noise Sensitive Receivers and Background Noise Climate_____________ 4-5

4.4 Construction Phase Impact____________________________________________________ 4-8

4.5 Operation Phase Impact_____________________________________________________ 4-22

4.6 Environmental Monitoring and Audit_____________________________________________ 4-35

4.7 Conclusion_______________________________________________________________ 4-35

Tables

Table 4.1:__ Noise Standards for Daytime Construction Activities_ 4-2

Table 4.2:__ Ground-borne Noise Criteria (L_{eq 30min}, dB(A)) 4-3

Table 4.3:__ Relevant Noise Standards for Planning Purposes_ 4-4

Table 4.4:__ Acceptable Noise Level for Fixed Plant Noise_ 4-4

Table 4.5:__ Area Sensitivity Rating_ 4-5

Table 4.6:__ Representative Noise Sensitive Receivers_ 4-7

Table 4.7__ Measured Noise Levels_ 4-8

Table 4.8:__ Unmitigated Construction Airborne Noise Impact near BCP, L_{eq (30mins)} dB(A) 4-9

Table 4.9__ Unmitigated Construction Airborne Noise Impact from Lin Ma Hang to Wo Keng Shan, L_{eq (30mins)} dB(A) 4-10

Table 4.10_ Unmitigated Construction Airborne Noise Impact at Wo Keng Shan, L_{eq (30mins)} dB(A) 4-10

Table 4.11_ Unmitigated Construction Airborne Noise Impact near Sha Tau Kok Road, L_{eq (30mins)} dB(A) 4-11

Table 4.12_ Unmitigated Construction Airborne Noise Impact near Po Kat Tsai, L_{eq (30mins)} dB(A) 4-11

Table 4.13_ Unmitigated Construction Airborne Noise Impact near Fanling, L_{eq (30mins)} dB(A) 4-11

Table 4.14_ Quieter PME Recommended for Adoption during Construction Phase_ 4-12

Table 4.15_ Noise Mitigation Measures for Certain PME during Construction Phase_ 4-13

Table 4.16:_ Mitigated Construction Airborne Noise Impact near BCP, L_{eq (30mins)} dB(A) 4-14

Table 4.17_ Mitigated Construction Airborne Noise Impact from Lin Ma Hang to Wo Keng Shan, L_{eq (30mins)} dB(A) 4-14

Table 4.18_ Mitigated Construction Airborne Noise Impact at Wo Keng Shan, L_{eq (30mins)} dB(A) 4-15

Table 4.19_ Mitigated Construction Airborne Noise Impact near Sha Tau Kok Road, L_{eq (30mins)} dB(A) 4-15

Table 4.20_ Mitigated Construction Airborne Noise Impact near Po Kat Tsai, L_{eq (30mins)} dB(A) 4-16

Table 4.21_ Mitigated Construction Airborne Noise Impact near Fanling, L_{eq (30mins)} dB(A) 4-16

Table 4.22:_ Cumulative Mitigated Construction Airborne Noise Impact near BCP, L_{eq (30mins)} dB(A) 4-17

Table 4.23_ Cumulative Mitigated Construction Airborne Noise Impact at Lin Ma Hang to Frontier Closed Area Boundary, L_{eq (30mins)} dB(A) 4-17

Table 4.24:_ Reference Vibration Level based on Measurements_ 4-19

Table 4.25:_ Source Vibration Velocity of Octave Band Frequency for Hydraulic Breaker 4-19

Table 4.26: _ Wave Propagation Properties of Soil 4-19

Table 4.27:_ Adjustment Factor for Building Coupling Loss (BCF) 4-20

Table 4.28:_ Adjustment Factor for Building Structure Attenuation (BSA) 4-20

Table 4.29:_ Building Structure Attenuation (BSA) 4-20

Table 4.30:_ Building Structure Resonance (BSR) 4-21

Table 4.31:_ Room Correction Factors_ 4-21

Table 4.32_ Unmitigated Construction Ground-borne Noise_ 4-22

Table 4.33_ Comparison between With and Without Project in Year 2018 from Lin Ma Hang to North Tunnel (Existing Receivers) 4-23

Table 4.34_ Comparison between With and Without Project in Year 2018 from Lin Ma Hang to North Tunnel (Planned Receivers) 4-24

Table 4.35_ Comparison between With and Without Project in Year 2018 near Sha Tau Kok Road Section (Existing Receivers) 4-25

Table 4.36_ Comparison between With and Without Project in Year 2018 near Fanling Highway (Existing Receivers)4-25

Table 4.37_ Unmitigated Road Traffic Noise Impact in Year 2033 near Lin Ma Hang to Wo Keng Shan (Existing Uses4-26

Table 4.38_ Unmitigated Road Traffic Noise Impact in Year 2033 near Lin Ma Hang to Wo Keng Shan (Planned Uses) 4-27

Table 4.39_ Unmitigated Road Traffic Noise Impact in Year 2033 near Sha Tau Kok Road Section (Existing Uses) 4-27

Table 4.40_ Unmitigated Road Traffic Noise Impact in Year 2033 near Fanling Highway (Existing Uses) 4-27

Table 4.41_ Summary of Exceedance of Road Traffic Noise Criteria_ 4-28

Table 4.42_ Proposed Location of Noise Barrier for Existing Uses_ 4-29

Table 4.43:_ Mitigated Road Traffic Noise Levels of Existing Uses_ 4-30

Table 4.44_ Noise Criteria of Fixed Plant Noise_ 4-31

Table 4.45:_ Summary of Fixed Plant Noise Sources_ 4-33

Table 4.46:_ Maximum SWLs of the Fixed Plant 4-33

Figures

Figure 1.1 Project Layout Plan

Figure 4.1.1 Assessment Area and Outline Zoning Plan

Figure 4.1.2 Recommended Development Plan (Sheet 1 of 2)

Figure 4.1.3 Recommended Development Plan (Sheet 2 of 2)

Figure 4.2 Representative Noise Sensitive Receivers (Sheet 1 of 11)

Figure 4.3 Representative Noise Sensitive Receivers (Sheet 2 of 11)

Figure 4.4 Representative Noise Sensitive Receivers (Sheet 3 of 11)

Figure 4.5 Representative Noise Sensitive Receivers (Sheet 4 of 11)

Figure 4.6 Representative Noise Sensitive Receivers (Sheet 5 of 11)

Figure 4.7 Representative Noise Sensitive Receivers (Sheet 6 of 11)

Figure 4.8 Representative Noise Sensitive Receivers (Sheet 7 of 11)

Figure 4.9 Representative Noise Sensitive Receivers (Sheet 8 of 11)

Figure 4.10 Representative Noise Sensitive Receivers (Sheet 9 of 11)

Figure 4.11 Representative Noise Sensitive Receivers (Sheet 10 of 11)

Figure 4.12 Representative Noise Sensitive Receivers (Sheet 11 of 11)

Figure 4.13 Photos of Noise Sensitive Receivers

Figure 4.14 Photos of Noise Sensitive Receivers

Figure 4.15 Photos of Noise Sensitive Receivers

Figure 4.16 Photos of Noise Sensitive Receivers

Figure 4.17 Photos of Noise Sensitive Receivers

Figure 4.18 Schematic Diagram of Movable Noise Barrier

Figure 4.19 Schematic Diagram of Full Noise Enclosure for PME

Figure 4.20.1 Proposed Location of Noise Barriers (Sheet 1 of 4)

Figure 4.20.2 Proposed Location of Noise Barriers (Sheet 2 of 4)

Figure 4.20.3 Proposed Location of Noise Barriers (Sheet 3 of 4)

Figure 4.20.4 Proposed Location of Noise Barriers (Sheet 4 of 4)

Figure 4.20.5 Cross-section Plans of Proposed Barriers

Figure 4.21.1 Fixed Plant of Boundary Control Point

Figure 4.21.2 Fixed Plant of North Tunnel North Portal

Figure 4.21.3 Fixed Plant of North Tunnel South Portal

Figure 4.21.4 Fixed Plant of Administration Building

Figure 4.21.5 Fixed Plant of South Tunnel North Portal

Figure 4.21.6 Fixed Plant of Mid-Ventilation Building

Figure 4.21.7 Fixed Plant of South Tunnel South Portal

Appendices

Appendix 4.1 Unmitigated Construction Plant Inventory

Appendix 4.2 Unmitigated Construction Airborne Noise Impacts

Appendix 4.3 Mitigated Construction Plant Inventory

Appendix 4.4 Mitigated Construction Airborne Noise Impacts

Appendix 4.5 Unmitigated Construction Ground-borne Noise Impacts

Appendix 4.6 Traffic Data and Road Traffic Network

Appendix 4.7 Comparison Scenario Between With and Without Project

Appendix 4.8 Unmitigated Road Traffic Noise Level

Appendix 4.9 Mitigated Road Traffic Noise Level

Appendix 4.10 Sample Calculation of Fixed Plant Noise

4. Noise Impact Assessment

4.1 Introduction

This section presents the assessment of the potential noise impacts associated with the construction and operation phases of the proposed BCP and associated facilities, according to section 3.4.4 of the Study Brief (ESB-199/2008) and Annexes 5 and 13 of the Technical Memorandum to the EIAO. Mitigation measures, where necessary, have been recommended accordingly to reduce the identified noise impacts to an acceptable level.

Potential noise impacts associated with the construction and operational phases of the Project have been assessed. Noise generated from various construction activities is the primary concern during the construction phase. Road traffic noise from the proposed connecting roads, fixed plant noise from ventilation shafts, as well as noise from fixed plant of the BCP are major noise impacts during the operational phase. Representative Noise Sensitive Receivers (NSRs) within 300m of the subject site have been identified and the worst case impacts on these receivers have been assessed. Suitable mitigation measures, where necessary, have been recommended to protect the NSRs and to ensure that the legislative criteria and guidelines can be satisfied.

4.2 Environmental Legislation, Standards and Guidelines

4.2.1 Construction Phase

Control over the generation of construction noise in Hong Kong is governed by the Noise Control Ordinance (NCO) and the EIAO and their subsidiary requirements. Various Technical Memoranda (TMs) have been issued under the NCO and the EIAO to stipulate control approaches and criteria. These TMs prescribe the maximum permitted noise levels for the use of Powered Mechanical Equipment (PME) and certain construction activities and processes, according to the type of equipment or activity, the perceived noise climate of the area, and the working hours of equipment operation and usage. The TMs applicable to the control of noise from construction activities of proposed construction works are:

¡ TM on Environmental Impact Assessment Process (EIAO-TM)

¡ TM on Noise from Construction Work other than Percussive Piling (GW-TM)

¡ TM on Noise from Construction Work in Designated Areas (DA-TM)

4.2.1.1 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) are assessed against the noise standards tabulated in Table 4.1 below.

Table 4.1: 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 above standards shall be viewed as the maximum permissible noise levels assessed at 1m from the external facade

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

4.2.1.2 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), only a small part of the works area of this project will fall within these areas where underground tunnelling works would be carried out.

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.

Regardless of any description or assessment made in this section, in assessing a filed application for a CNP the Authority will be guided by the relevant Technical Memoranda. The Authority will consider all the factors affecting their decision taking contemporary situations/ conditions into account. Nothing in this Report shall pre-empt the Authority in making their decisions, and there is no guarantee that a CNP will be issued. If a CNP is to be issued, the Authority may include any conditions they consider appropriate and such conditions are to be followed while the works covered by the CNP are being carried out. Failing to do so may lead to cancellation of the permit and prosecution action under the NCO.

According to the construction programme, the proposed construction works would be carried out during non-restricted hours. In case of any construction activities during restricted hours, it is the Contractor’s responsibility to ensure compliance with the NCO and the relevant TMs. The Contractor will be required to submit CNP application to the Noise Control Authority and abide by any conditions stated in the CNP, should one be issued.

4.2.1.3 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 4.1. 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 4.2.

Table 4.2: Ground-borne Noise Criteria (L_{eq 30min}, dB(A))

NSR type	Ground-borne Noise Criteria ^(1), dB(A)
	Daytime (0700-1900) 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^(2,3)	35/40/45^(2,3)
Hotels and hostel
Educational institutions including kindergarten, nurseries and all others where unaided voice communication is required	60 55 (for during examination)	N/A^(4)	N/A^(4)
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) 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. (3) Construction Noise Permit is required for works during this period. (4) No sensitive use in Education institutions during evening and night-time period is assumed except specified.

4.2.1.4 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 assessment generated by this activity is beyond the scope of the EIA. However, it is expected that the impact due to blasting shall be minimal as the blasting location is deep underground (about 40m below ground level of the identified ground-borne NSRs) and far away from the noise sensitive receivers and most of the blasting will be carried out inside tunnel. Nevertheless good site practices such as installation of blasting door at tunnel portals or equivalent measures and proper schedule of blasting time (e.g. during non sensitive hours) shall be implemented by the Contractor so to avoid the potential disturbance that may be caused.

4.2.2 Operation Phase

4.2.2.1 Road Traffic Noise

The Technical Memorandum (TM) published under Section 16(5) of the Environmental Impact Assessment Ordinance (EIAO) gazetted in 1997, is the fundamental legislation of noise criteria for evaluating noise impact of designated projects. The summary of noise criteria is given in Table 4.3.

Table 4.3: Relevant Noise Standards for Planning Purposes

Uses	Road Traffic Noise Peak Hour Traffic L10 (1hour), dB(A)
All domestic premises including temporary housing accommodation	70
Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required	65

Notes: (i) The above standards apply to uses which rely on opened windows for ventilation

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

4.2.2.2 Fixed Plant Noise

For the fixed plant noise assessment, the ANLs for the NSRs are determined based on the Area Sensitivity Rating (ASR).

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 4.4.

Table 4.4: 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).

4.2.2.3 Area Sensitivity Rating (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 4.5. Industrial area, major road or the area within the boundary of Hong Kong International Airport shall be considered to be an IF.

Table 4.5: 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

4.3 Assessment Area, Noise Sensitive Receivers and Background Noise Climate

4.3.1.1 Assessment Area

The Assessment Area is defined as within 300m of the site boundary of the Project for noise impact assessment. This assessment area is identified and shown in Figure 4.1.1.

4.3.1.2 Noise Sensitive Receivers (NSRs)

Noise Sensitive Receivers (NSRs) have been identified in accordance with Annex 13 of the EIAO-TM. The NSRs have included existing, planned/ committed noise sensitive developments and relevant uses earmarked on the relevant Outline Zoning Plans, Development Permission Area Plans, Outline Development Plans, Layout Plans and other relevant published land use plans, including plans and drawings published by Lands Department. The Outline Zoning Plans within the assessment area are shown in Figure 4.1.1.

There are numerous village houses situated along the proposed BCP and the connecting road which are identified as NSRs. For the purpose of noise assessment, the first layer of houses of each village located close to the site boundary have been selected as assessment points/ identified representative NSRs within the Study Area for prediction of noise impact levels.

According to the Outline Zoning Plans (S/NE-TKL/13 – Ping Che & Ta Kwu Ling, S/NE-WKS/10 – Wo Keng Shan, S/NE-MUP/11 – Man Uk Pin, S/NE-KLH/11 – Kau Lung Hang) located within the works area, there are Village Type Development zoning (“V” zone) near Nga Yiu Ha, Ping Yeung, Wo Keng Shan, Tai Tong Wu, Loi Tung and Kau Lung Hang. Construction of New Territories Exempted House is permitted in this zoning. Existing NSRs in those “V” zone located close to the site boundary have been identified and selected as representative NSRs. It is identified that the first layer of existing NSRs does not cover the worst affected location of the “V” zone at Wo Keng Shan. Hence an assessment point i.e. WKS8 has been selected to represent a planned NSR in the area.

It is noted that some of the existing NSRs along the proposed road alignment are located in the Agriculture and Green Belt zonings. Construction of new New Territories Exempted House outside the 'V' Zones would require planning permission from the Town Planning Board under Section 16 of the Town Planning Ordinance. At the time of preparation of this Report, no approved application for such planned development was identified along the site boundary of the Project.

According to the North East New Territories New Development Areas (NENT NDAs) Planning and Engineering Study – Investigation (2009), part of the Ping Che/ Ta Kwu Ling NDA is located within the Study Area. However, the study is still in progress and land uses within the NDA has not been finalised. As first layer of NSRs have been selected as assessment points, no additional assessment point has been selected for the NDA.

According to the planned programme (see Appendix 2.2), the Chuk Yuen Village Resite will be completed in early 2012 for population intake by early 2013, and construction of this Project will commence in around mid 2013. Therefore, the existing Chuk Yuen Village that is within the BCP site will have been relocated to the Resite (as represented by NSR CY3) before commencement of construction of this Project. Hence, the existing Chuk Yuen Village located within the future BCP site will not be subject to any construction or operational phase impacts of this Project, and is not included in this assessment. However, the Chuk Yuen Village Resite (NSR CY3) will be subject to both construction and operational phase impacts, and is included in the assessment.

Based on the Recommended Development Plan in the Final Report (July 2010) of Planning Department’s Land Use Planning for the Closed Area – Feasibility Study (see Figures 4.1.2 and 4.1.3), areas of Tsung Yuen Ha, Chuk Yuen and Kan Tau Wai fall within the Study Area of this noise impact assessment are proposed to be zoned as “V” zone. As the existing NSR TYH in Tsung Yuen Ha and NSR CY3 in Chuk Yuen have been selected, no additional planned assessment point has been added for these two “V” zones. However an additional assessment point i.e. KTW6 has been added to represent a planned NSR in the proposed “V” zone at Kan Tau Wai.

Descriptions of selected representative NSRs are tabulated in Table 4.6. The representative NSRs are shown in the Figures 4.2 to 4.12. Photos of existing noise sensitive receivers are shown in Figures 4.13 to 4.17.

Table 4.6: Representative Noise Sensitive Receivers

4.3.1.3 Background Noise Climate

Noise surveys were carried out from November 2009 to April 2010 to investigate the background noise condition of the surrounding environment and the Project Area. Figures 4.2 to 4.12 show the baseline noise measurement locations.

Five noise measurements were carried out in the Project Area. The noise measurements were undertaken using Type 1 sound level meters, namely Rion NL-18 and Rion NL-31. During each measurement, the sound level meter was checked using an acoustic calibrator generating a sound pressure level of 94dB(A) at 1kHz immediately before and after the noise measurement. The measurements were accepted as valid only if the calibration levels before and after the noise measurement were agreed to within 1.0dB(A). Moreover, the sound level meters and acoustic calibrators are calibrated in accredited laboratories yearly to ensure reliable performance. The measurement results are shown in Table 4.7.

Table 4.7 Measured Noise Levels

Location ID	Location Description	Time Period	Start Time	Measured Noise Level in Leq(30min), dB(A)	Corrected Facade Noise Level, dB(A)
A	Tsung Yuen Ha	Daytime (0700 – 1900)	07:15	49	52
		Evening Time (1900 – 2300)	19:00	46	49
		Night-time (2300 – 0700)	06:15	42	45
B	Ng Chau Road	Daytime (0700 – 1900)	15:30	53	56
		Evening Time (1900 – 2300)	19:20	49	52
		Night-time (2300 – 0700)	05:45	43	46
C	Wo Keng Shan	Daytime (0700 – 1900)	09:15	51	54
		Evening Time (1900 – 2300)	20:15	44	47
		Night-time (2300 – 0700)	23:15	42	45
D	Loi Tung	Daytime (0700 – 1900)	16:10	46	49
		Evening Time (1900 – 2300)	19:20	41	44
		Night-time (2300 – 0700)	05:25	40	43
E	Po Kat Tsai	Daytime (0700 – 1900)	10:40	43	46
		Evening Time (1900 – 2300)	20:15	33	36
		Night-time (2300 – 0700)	23:30	33	36

4.4 Construction Phase Impact

4.4.1 Construction Airborne Noise

4.4.1.1 Identification of Emission Source

The major construction activity involved in the Project is the site formation for the construction of a BCP building, construction of a dual two-lane trunk road with connecting the BCP with Fanling Highway adjacent to Wo Hop Shek by tunnelling and open-cut methods.

4.4.1.2 Assessment Methodology

Assessment approach to the noise impact is in line with the Guidance Note titled “Preparation of Construction Noise Impact Assessment under the Environmental Impact Assessment Ordinance” (GN 9/2004).

In addition, the assessment of construction noise impact is based on standard acoustic principles, and the guidelines given in GW-TM issued under the NCO where appropriate. Where no sound power level (SWL) can be found in the relevant TM, reference has been made to BS 5228 Part I or noise emission levels measured for PME used in previous projects in Hong Kong. The general approach is summarized below:

i. Assume a typical construction schedule/ programme;

ii. Assume a typical project-specific equipment inventory for each work stage together with the number;

iii. Obtain from GW-TM, the Sound Power Level (SWL) for each PME assumed in the equipment inventory;

iv. Select representative NSRs for the construction noise impact assessment;

v. Calculate the unmitigated Predicted Noise Level (PNL) and correct it for facade reflection to obtain the Corrected Noise Level (CNL) at any NSRs;

vi. If necessary, re-select typical project-specific silenced equipment and calculate the mitigated noise impact;

vii. Compare the mitigated CNL with the noise standards to determine acceptability and the need for further mitigation.

The calculation methodology is estimated with the following standard formula (1):

SPL = SWL – DC + FC (1)

where

Sound Pressure Levels, SPL in dB(A)

Sound Power Levels, SWL in dB(A)

Distance Attenuation, DC in dB(A) = 20∙log(D)+8 (where D is the distance between NSRs and noise source in meters)

Façade Correction, FC in dB(A) = 3dB(A)

4.4.1.3 Evaluation of Impacts

The type and quantity of Powered Mechanical Equipment (PME) likely to be used for the construction of the BCP and associated road works are described below and their Sound Power Levels (SWLs) are shown in Appendix 4.1.

Table 4.8 to Table 4.13 and Appendix 4.2 indicates that the noise impact of unmitigated construction activities of proposed road works would cause exceedance of the relevant daytime construction noise criteria. Mitigation measures are therefore required for these NSRs in order to alleviate the noise impacts generated during the construction phase.

Table 4.8: Unmitigated Construction Airborne Noise Impact near BCP, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Mitigation measure required
TYH	Residential	69-80	75	Yes	Yes

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.9 Unmitigated Construction Airborne Noise Impact from Lin Ma Hang to Wo Keng Shan, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Mitigation measure required
V1	Residential	56-87	75	Yes	Yes
V2	Residential	55-88	75	Yes	Yes
CY3	Residential	55-76	75	Yes	Yes
KL1	Residential	50-79	75	Yes	Yes
TKL1	Residential	49-85	75	Yes	Yes
TKL2	Residential	48-85	75	Yes	Yes
KTW1	Residential	56-80	75	Yes	Yes
KTW2	Residential	53-83	75	Yes	Yes
KTW3	Residential	57-83	75	Yes	Yes
KTW4	Residential	55-89	75	Yes	Yes
KTW5	Residential	58-83	75	Yes	Yes
NYH1	Residential	64-84	75	Yes	Yes
NYH2	Residential	65-79	75	Yes	Yes
PY2	Residential	67-91	75	Yes	Yes
PY3	Residential	59-82	75	Yes	Yes
PY4	Residential	59-89	75	Yes	Yes
PY5	Residential	58-81	75	Yes	Yes
PY6	Residential	57-82	75	Yes	Yes
PY7	Residential	57-76	75	Yes	Yes

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.10 Unmitigated Construction Airborne Noise Impact at Wo Keng Shan, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Mitigation measure required
WKS1	Residential	66-81	75	Yes	Yes
WKS2	Residential	64-77	75	Yes	Yes
WKS3	Residential	62-72	75	No	No
WKS4	Residential	68-84	75	Yes	Yes
WKS5	Residential	64-89	75	Yes	Yes
WKS6	Residential	60-89	75	Yes	Yes
WKS7	Residential	60-85	75	Yes	Yes

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.11 Unmitigated Construction Airborne Noise Impact near Sha Tau Kok Road, L_{eq (30mins)} dB(A)

NSR ID	Land Use	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Mitigation measure required
ST1	Residential	69-82	75	Yes	Yes
ST2	Residential	68-85	75	Yes	Yes
ST3	Residential	61-79	75	Yes	Yes
ST5	Residential	64-84	75	Yes	Yes
ST6	Residential	59-80	75	Yes	Yes
LT1	Residential	58-85	75	Yes	Yes
LT2	Residential	55-79	75	Yes	Yes
LT3	Residential	59-83	75	Yes	Yes
LT4	Residential	76-78	75	Yes	Yes
TTW1	Residential	60-74	75	No	No
TTW2	Residential	63-85	75	Yes	Yes

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.12 Unmitigated Construction Airborne Noise Impact near Po Kat Tsai, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Mitigation measure required
PKT1	Residential	63-72	75	No	No
PKT2	Residential	78-86	75	Yes	Yes
PKT3	Residential	77-84	75	Yes	Yes

Table 4.13 Unmitigated Construction Airborne Noise Impact near Fanling, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Mitigation measure required
TH1	Residential	56-87	75	Yes	Yes
TH2	Residential	57-81	75	Yes	Yes
TH4	Residential	54-84	75	Yes	Yes
TH5	Residential	55-79	75	Yes	Yes
TH6	Residential	53-73	75	No	No
WKS1	Residential	55-72	75	No	No
KT1	Residential	59-82	75	Yes	Yes
KT2	Residential	64-86	75	Yes	Yes
KT3	Residential	62-91	75	Yes	Yes
NWP1	Residential	62-91	75	Yes	Yes
KLHSW	Residential	61-82	75	Yes	Yes

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

4.4.1.4 Mitigation Measures

Mitigation measures for each construction site are detailed below, and the following forms of mitigation measures are recommended and should be incorporated into the Contract Specifications:

¡ good site practice to limit noise emissions at source;

¡ selection of quieter plant;

¡ use of movable noise barrier;

¡ use of noise enclosure/ acoustic shed; and

¡ use of noise insulating fabric.

While it is recognised that the Contractor may develop a different package of mitigation measures to meet the required noise standards, the following suite of practical and implementable measures demonstrate an approach that would be feasible to reduce noise to acceptable levels.

Good Site Practice

Good site practice and noise management can significantly reduce the impact of construction site activities on nearby NSRs. The following package of measures should be followed during each phase of construction:

¡ only well-maintained plant to be operated on-site and plant should be serviced regularly during the construction works;

¡ machines and plant that may be in intermittent use to be shut down between work periods or should be throttled down to a minimum;

¡ plant known to emit noise strongly in one direction, should, where possible, be orientated to direct noise away from the NSRs;

¡ mobile plant should be sited as far away from NSRs as possible; and

¡ material stockpiles and other structures to be effectively utilised, where practicable, to screen noise from on-site construction activities.

Selecting Quieter Plant

The Contractor may be able to obtain particular models of plant that are quieter than the standards given in the GW-TM. This is one of the most effective measures and is increasingly practicable because of the availability of quiet equipment.

Quiet plant is defined as QPME whose actual SWL is less than the value specified in GW-TM for the same piece of equipment. Examples of SWLs for specific silenced PME taken from a British Standard, namely Noise Control on Construction and Open Sites, BS 5228: Part 1: 2009 and are presented in Table 4.14. It should be noted that various types of silenced equipment can be found in Hong Kong.

Table 4.14 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	0.75kW each poker	BS D6-40	102
Bulldozer	239kW	BS D3-27	109
Excavator	45kW	BS D3-35	106
Dump truck	50t	BS D9-39	103
Vibratory roller	9kW	BS D3-115	102
Asphalt paver	90kW	BS D8-24	101
Road Roller	51kW	BS D8-30	101
Lorry	310kW	BS D3-59	105

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 Barriers

Movable noise barriers can be very effective in screening noise from particular items of plant when constructing the Project. Noise barriers located along the active works area close to the noise generating component of a PME could produce at least 10 dB(A) screening for stationary plant and 5 dB(A) for mobile plant provided the direct line of sight between the PME and the NSRs is blocked. A schematic configuration of a single movable noise barrier for PME is shown in Figure 4.18.

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 EIAO Guidance Note No.9/2004. A schematic configuration of full noise enclosure for PME is shown in Figure 4.19.

Use of Noise Insulating Fabric

Noise insulating 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. According to the approved Tsim Sha Tsui Station Northern Subway EIA Report (AEIAR-127/2008), a noise reduction of 10 dB(A) can be achieved for the PME lapped with the noise insulating fabric.

The noise screening benefit for each item of plant considered in this assessment is listed in Table 4.15.

Table 4.15 Noise Mitigation Measures for Certain PME during Construction Phase

PME	Mitigation Measures Proposed	Noise Reduction, dB(A)
Concrete pump	Noise enclosure	15
Air compressor	Noise enclosure	15
Grout pump	Noise enclosure	15
Handheld breaker	Movable noise barrier	10
Piling, large diameter bored, grab and chisel	Noise insulating fabric	10
Piling, large diameter bored, reverse circulation drill	Noise insulating fabric	10
Piling, large diameter bored, oscillator	Noise insulating fabric	10
Piling, diaphragm wall, bentonite filtering plant	Noise insulating fabric	10
Drill rig, rotary type	Noise insulating fabric	10
Air compressor	Movable noise barrier	10
Water pump	Movable noise barrier	10
Generator	Movable noise barrier	10
Poker, Vibratory, hand-held	Movable noise barrier	10
Excavator	Movable noise barrier	5
Mobile crane	Movable noise barrier	5
Prestress Jack	Movable noise barrier	5
Lorry with crane/grab	Movable noise barrier	5
Lorry	Movable noise barrier	5
Compactor, vibratory	Movable noise barrier	5
Bulldozer	Movable noise barrier	5
Asphalt paver	Movable noise barrier	5
Road Roller	Movable noise barrier	5
Dump Truck	Movable noise barrier	5
Concrete pump, lorry mounted	Movable noise barrier	5

These noise barriers should be free of gaps and made of materials having a surface mass density in excess of 7 kg/m². To improve the effectiveness of noise reduction, non-flammable absorptive lining can be adhered on the inner surface of the noise barriers. The barrier can be in the form of vertical or bend top barrier with an effective height to block the line of sight to NSRs. Given most of the NSRs are low storeys (i.e. 1-2 storey), the movable noise barriers is effective to screen the noise from the construction plant.

The effect of the use of quiet plant and using movable barriers has been investigated for the practicable construction activities and the results are presented in Table 4.16 to Table 4.21 and the detailed calculation was shown in Appendix 4.4.

Table 4.16: Mitigated Construction Airborne Noise Impact near BCP, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Residual Impact
TYH	Residential	64-70	75	No	No

Table 4.17 Mitigated Construction Airborne Noise Impact from Lin Ma Hang to Wo Keng Shan, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Residual Impact
V1	Residential	51-72	75	No	No
V2	Residential	51-74	75	No	No
CY3	Residential	50-67	75	No	No
KL1	Residential	45-65	75	No	No
TKL1	Residential	44-71	75	No	No
TKL2	Residential	44-71	75	No	No
KTW1	Residential	43-67	75	No	No
KTW2	Residential	40-69	75	No	No
KTW3	Residential	44-69	75	No	No
KTW4	Residential	42-72	75	No	No
KTW5	Residential	45-69	75	No	No
NYH1	Residential	53-70	75	No	No
NYH2	Residential	56-66	75	No	No
PY2	Residential	56-75	75	No	No
PY3	Residential	47-68	75	No	No
PY4	Residential	48-72	75	No	No
PY5	Residential	47-68	75	No	No
PY6	Residential	46-69	75	No	No
PY7	Residential	45-63	75	No	No

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.18 Mitigated Construction Airborne Noise Impact at Wo Keng Shan, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Residual Impact
WKS1	Residential	62-70	75	No	No
WKS2	Residential	60-69	75	No	No
WKS3	Residential	57-64	75	No	No
WKS4	Residential	55-71	75	No	No
WKS5	Residential	60-72	75	No	No
WKS6	Residential	57-75	75	No	No
WKS7	Residential	57-72	75	No	No

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.19 Mitigated Construction Airborne Noise Impact near Sha Tau Kok Road, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Residual Impact
ST1	Residential	59-69	75	No	No
ST2	Residential	58-72	75	No	No
ST3	Residential	51-67	75	No	No
ST5	Residential	52-72	75	No	No
ST6	Residential	49-67	75	No	No
LT1	Residential	48-71	75	No	No
LT2	Residential	45-69	75	No	No
LT3	Residential	50-71	75	No	No
LT4	Residential	64-70	75	No	No
TTW1	Residential	50-61	75	No	No
TTW2	Residential	53-74	75	No	No

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

Table 4.20 Mitigated Construction Airborne Noise Impact near Po Kat Tsai, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Residual Impact
PKT1	Residential	54-59	75	No	No
PKT2	Residential	68-73	75	No	No
PKT3	Residential	67-71	75	No	No

Table 4.21 Mitigated Construction Airborne Noise Impact near Fanling, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Exceedance of noise criteria dB(A)	Residual Impact
TH1	Residential	43-73	75	No	No
TH2	Residential	44-67	75	No	No
TH4	Residential	42-70	75	No	No
TH5	Residential	42-65	75	No	No
TH6	Residential	41-60	75	No	No
WKS1	Residential	42-58	75	No	No
KT1	Residential	46-67	75	No	No
KT2	Residential	52-71	75	No	No
KT3	Residential	50-75	75	No	No
NWP1	Residential	50-75	75	No	No
KLHSW	Residential	49-68	75	No	No

Note: Bold figures denotes the predicted noise level is higher than the relevant daytime construction noise criteria

With the incorporation of quiet plant and the use of movable noise barriers (to reduce noise level at source), the results indicated that the mitigated noise impact associated with the construction of the Project would comply with the daytime construction noise criterion at all the NSRs. Residual construction noise impact is not anticipated.

The mitigation measures recommended above can be altered, the Contractor may be allowed to use acoustic blankets on PMEs or re-schedule noisy works, while it is the responsibility of the Contractor to comply with the construction noise criteria which should be stated in the contractual agreement. It is further recommended that the Contractor should follow the “Recommended Pollution Control Clauses for Construction Contracts” to minimise the construction noise impact.

4.4.1.5 Cumulative Construction Airborne Noise Impact

According to the tentative construction programme, it is likely that there will be an overlap of this Project with some other potentially concurrent projects. These projects are described in Section 2.10.

For projects “Regulation of Shenzhen River Stage IV” and “Construction of a Secondary Boundary Fence and new sections of Primary Boundary Fence and Boundary Patrol Road”, the cumulative impact results in the EIA Report of the Regulation of Shenzhen River Stage IV has been referenced. Below is the summary of the cumulative noise impact at the NSRs.

Table 4.22: Cumulative Mitigated Construction Airborne Noise Impact near BCP, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)		Max. Overall Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of noise criteria, dB(A)	Residual Impact
		This Project	*Concurrent Projects
TYH	Residential	64-70	54 - 71	74	75	No	No

Note: (*) reference to the predicted results of the closest NSR in the EIA Report of the Regulation of Shenzhen River Stage IV with appropriate distance correction

Table 4.23 Cumulative Mitigated Construction Airborne Noise Impact at Lin Ma Hang to Frontier Closed Area Boundary, L_{eq (30mins)} dB(A)

NSR ID	Usage	Predicted Noise Level dB(A)		Max. Overall Noise Level, dB(A)	Noise Criteria, dB(A)	Exceedance of noise criteria, dB(A)	Residual Impact?
		This Project	*Concurrent Projects
KL1	Residential	45-65	53 - 63	67	75	No	No
TKL1	Residential	44-71	57 - 67	72	75	No	No
TKL2	Residential	44-71	53 - 63	72	75	No	No

Note: (*) reference to the predicted results of the closest NSR in the EIA Report of the Regulation of Shenzhen River Stage IV with appropriate distance correction

For the project “Resite of Chuk Yuen Village”, as the construction of the BCP Project will be commenced after the resite of the Chuk Yuen Village, no cumulative impact is anticipated.

For project “North East New Territories (NENT) Landfill Extension”, the project boundary and works areas are out of the 300m from this Project’s boundary and therefore not applicable for concurrent noise impact assessment.

According to the project proponent, the implementation programme of Stage 2 of the Tolo/Fanling Highway widening project is currently under review. It is understood that there will be overlap between this project and the LT/HYW Project. However the project programme has not been confirmed at the time of preparation of this Report, cumulative impact of this project has not been taken into account.

As mentioned in Section 2.10.9, the project “Provision of Cremators at Wo Hop Shek Crematorium” is located outside 500m from the site boundary of the BCP Project, the project will not be considered as a concurrent project.

For project “Cycle Tracks Connecting North West New Territories with North East New Territories – Sheung Shui to Ma On Shan section”, the section of the Cycle Track which intersects the LT/HYW BCP Project’ study area (Fanling section) is due to be completed by mid 2012. No cumulative impacts are anticipated and hence the project will not be considered as a concurrent project.

For the project “Drainage Improvements in Northern New Territories – Package C (Remaining Works)”, the site area is located outside 300m from the site boundary of the BCP Project and hence the project will not be considered as a concurrent project.

4.4.1.6 Evaluation of Residual Impact

With the implementation of the above-mentioned mitigation measures, the construction noise levels at all the representative NSRs are predicted to comply with the noise standards stipulated in the EIAO-TM. No residual construction noise impact is anticipated. Nevertheless, the Contractor is recommended to implement the good site practice as mentioned in Section 4.4.1.4 and carry out the environmental monitoring and audit (EM&A) to be discussed in Section 4.6.

4.4.2 Construction Ground-borne Noise

4.4.2.1 Identification of Emission Source

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

4.4.2.2 Assessment Methodology

Drill & Blast and Mechanical Excavation methods would be used to excavate rock along the alignment. The interaction between the operation of equipment and the rock will induce ground-borne noise. The prediction methodology for assessing the ground-borne noise impact from construction equipment is detailed as follows:

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 + C cum
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
C cum	Cumulative noise impact from concurrent projects

Reference Vibration Sources

The vibratory velocities for typical construction equipment with reference to the approved Kowloon Southern Link EIA (Register No.: AEIAR-083/2005) are listed in Table 4.24 to Table 4.25.

Table 4.24: Reference Vibration Level based on Measurements

Construction Equipments	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 4.25: 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 4.26.

Table 4.26: 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 (BCL)

Interaction between the building foundation and the soil will cause some reduction in the vibration level. The correction factors shown in Table 4.27 are based on Saurenman (1982). For conservative assessment, the lower limit adjustment factors (highlighted in Bold) have been used in the study.

Table 4.27: 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
	Upper	-8	-10	-13	-15	-16	-14
Large Masonry Building on Spread Footings	Lower	-12	-14	-14	-13	-11	-10
	Upper	-14	-16	-16	-15	-13	-12
1 to 2 Storey Residential	Lower	-4	-5	-5	-4	-3	-1
	Upper	-6	-7	-7	-6	-5	-3
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. The following correction factors (Table 4.28) based on Saurenman (1982)^[2] are proposed for the Project.

Table 4.28: 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 2dB per octave band (Table 4.29) is proposed for the Project.

Table 4.29: Building Structure Attenuation (BSA)

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 4.30) has been adopted for the Project in accordance with the FTA Handbook[3] recommendation.

Table 4.30: Building Structure Resonance (BSR)

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 4.4‑1 CTN = Krad + A-weighting Correction Equation 4.4‑2 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 4.31) are proposed for the Project:

Table 4.31: 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 C _multi

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 C _cum

Potential concurrent projects leading to cumulative impacts would be considered in the ground-borne noise prediction.

4.4.2.3 Evaluation of Construction Ground-borne Noise Impacts

Detailed assessments have been conducted for three construction equipment (hydraulic breaker, hand-held breaker and drilling rig), for tunnelling works including drill & blast and mechanical excavation along the tunnel, the results are summarised in Table 4.32. The detailed assessment results were shown in Appendix 4.5.

Table 4.32 Unmitigated Construction Ground-borne Noise

NSR ID	Usage	Predicted Noise Level dB(A)	Noise Criteria dB(A)	Mitigation measure required
LPT	Residential	34	65	No
STS	Residential	34	65	No

Based on the assessment result as shown in Table 4.32, the predicted ground-borne noise levels from the tunnelling work will not exceed the daytime ground-borne noise criteria and hence no mitigation measures are required.

4.5 Operation Phase Impact

4.5.1 Road Traffic Noise

4.5.1.1 Identification of Emission Source

During the operational phase, operation of the LT/HYW BCP connecting road may pose traffic noise impact on the nearby NSRs. The road carriageways involved within the assessment area, including the proposed BCP connecting road, the modified Lin Ma Hang Road, existing roads and roads of other committed projects have been selected for assessment. Appendix 4.6 shows the roads selected for the Road Traffic Noise Impact Assessment (RTNIA). The classification of “New Road” and “Existing Road” are also shown in Appendix 4.6.

4.5.1.2 Assessment Methodology

Road traffic noise levels at the representative assessment points will be calculated based on the peak hour traffic flow within a 15 years period upon commencement of operation of the Project i.e., the assessment year. Traffic noise will be predicted using the model “roadNoise”, which has been used before in other similar EIA studies. The model has fully incorporated the procedures and methodology documented in “Calculation of Road Traffic Noise (CRTN)” (1988) published by the U.K. Department of Transport.

In accordance with the requirements specified in Section 3.4.4.2(vi)(a) of the EIA Study Brief, a number of specified scenarios have been studied as part of the road traffic noise impact assessment. These scenarios are summarized below:

■ Scenario (1) includes a comparison of the “with and without Project” situations at the design year to identify the significance of road traffic noise at the representative NSRs. Predicted traffic noise impact would be considered to be significant if the traffic noise levels in the presence of the Project is greater than that without the Project at the design year (i.e. 2018) by 1.0 dB(A) or more;

■ Scenario (2) involves an assessment of the unmitigated road traffic noise levels at the representative NSRs at the assessment year. If exceedances of the relevant road traffic noise criteria are predicted, direct noise mitigation measures listed under Section 6.1 in Annex 13 of EIAO-TM will be considered;

■ Scenario (3) involves an assessment of the effectiveness and adequacy of the recommended direct noise mitigation measures. It is envisaged that the direct noise mitigation measures proposed may involve erection of noise barriers and/or enclosure on the BCP connecting road. Aesthetic design and greening measures will be considered for the noise barriers to ensure that visual intrusion is minimised to acceptable levels. Sections of barriers proposed to protect existing NSRs will be differentiated clearly from those proposed for the protection of planned NSRs;

■ Under Scenario (4), upon exhaust of all practicable direct noise mitigation measures, in case noise exceedances are still predicted at existing NSRs (e.g. dwellings and classrooms), the eligibility of the affected NSRs for provision of indirect technical remedies in form of noise insulation and air-conditioning will be evaluated based on the three specific criteria set out in Section 3.4.4.2 (vi)(a3) of the EIA Study Brief. For noise exceedances predicted at planned NSRs, extent of additional noise mitigation measures required to be incorporated into the design of the planned NSRs will be defined (e.g. in terms of setback distances required at a certain view angle).

If the NSRs are affected by noise from other existing roads, direct mitigation measures are required to reduce the noise from the proposed roads to a level that it

■ is not higher than the standard; and

■ has no significant contribution to the overall noise from other existing roads

If the noise criteria will still be exceeded at the existing NSRs after the implementation of direct mitigation measures, provision of acoustic insulation in form of windows and provision of air-conditioning for ventilation should be considered under the ExCo directive “Equitable Redress for Persons Exposed to Increased Noise Resulting from the use of New Roads”. Eligibility for indirect technical remedies should be tested against the following three criteria:

■ The predicted overall noise level, L_{10(1 hour)}, from the “New Road”, together with other traffic noise in the vicinity must be above 70 dB(A) for domestic premises, 65 dB(A) for educational institutions and 55 dB(A) for home for the aged.

■ The predicted overall noise level is at least 1.0 dB(A) more than the prevailing traffic noise level.

■ The contribution to the increase in the predicted overall noise level from the “New Road” must be at least 1.0 dB(A).

The road scheme within the Study Area and the surrounding road network have been set up to define the road width, surface type, traffic condition and if applicable, the height and locations of any roadside barriers. Parapet walls with height of 0.8m above road surface along both sides of the viaduct sections of the proposed link road have been applied. In accordance with RD/GN/032, the extent of low-noise surfacing will cover the link roads and slip roads, but not the local road sections i.e. the roundabouts at Sha Tau Kok Road and Ping Yeung, Lin Ma Hang Road, Tai Wo Service Roads etc. This has been applied in the unmitigated scenario.

4.5.1.3 Evaluation of impacts

Scenario (1)

The comparison between with and without the Project at Year 2018 (AM) due to operation of the Proposed Connecting Road and existing roads network nearby are summarised in Table 4.33 to Table 4.36. Detailed breakdown of road traffic noise is shown in Appendix 4.7.

Table 4.33 Comparison between With and Without Project in Year 2018 from Lin Ma Hang to North Tunnel (Existing Receivers)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)		Difference, dB(A) (2) – (1)
		Without Project (1)	With Project (2)
TYH	70	52	62	10.5 - 10.6
V1	70	64	69	5.5 – 5.8
V2	70	58	64 - 65	6.7 – 7.4
KL1	70	60	63 - 64	3.6 – 3.7
TKL1	70	62	66	3.3 – 3.4
TKL2	70	65	69	3.9 – 4.0
KTW1	70	52	63 - 64	10.6 – 11.5
KTW2	70	32	59	27.2
KTW3	70	46	65 - 66	18.4 – 20.0
KTW4	70	40	58	18.0
KTW5	70	46	64 - 66	18.5 – 19.9
NYH1	70	42	65 - 66	22.4 – 23.5
NYH2	70	34	64 - 65	30.3 – 30.8
PY1	70	0	69 - 70	69.2 – 69.5
PY2	70	37	69	31.5 – 32.2
PY3	70	37	65 - 66	28.4 – 28.9
PY4	70	38	67	29.1
PY5	70	0	65	65.0
PY6	70	34	66	31.9
PY7	70	21 - 24	64 - 65	40.6 – 42.9
WKS1	70	52	71	18.7
WKS2	70	54	66	11.7 – 12.1
WKS3	70	52	64	11.5 – 11.7
WKS4	70	66	71	4.8
WKS5	70	66	68	2.1
WKS6	70	62	68	5.3
WKS7	70	67	70	2.7

Notes: Bold figure denotes the noise exceedance which is over the relevant EIAO-TM noise criteria.

Table 4.34 Comparison between With and Without Project in Year 2018 from Lin Ma Hang to North Tunnel (Planned Receivers)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)		Difference, dB(A) (2) – (1)
		Without Project (1)	With Project (2)
CY3	70	(*)	61 - 62	(*)
KTW6	70	64	66 - 67	2.1 – 2.2
WKS8	70	50	68	17.9 – 18.4

Notes: (*)CY3 exists in the "with project" scenario only.

Table 4.35 Comparison between With and Without Project in Year 2018 near Sha Tau Kok Road Section (Existing Receivers)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)		Difference, dB(A) (2) – (1)
		Without Project (1)	With Project (2)
ST1	70	47-53	63-64	12.8 – 15.7
ST2	70	57	67-68	9.7 – 11.2
ST3	70	60	68	8.1 – 8.2
ST5	70	64	72	8.6 – 8.7
ST6	70	62	71	8.1 – 8.3
TTW1	70	67	67	-0.5
TTW2	70	64	68	3.6
LT1	70	60	74	14.3
LT2	70	62	70	8.3
LT3	70	68	73	5.1 – 5.2
LT4	70	51	70	18.9 – 19.0

Notes: Bold figure denotes the noise exceedance which is over the relevant EIAO-TM noise criteria.

Table 4.36 Comparison between With and Without Project in Year 2018 near Fanling Highway (Existing Receivers)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)		Difference, dB(A) (2) – (1)
		Without Project (1)	With Project (2)
TH1	70	70	75	4.8
TH2	70	70	72	2.1 – 2.2
TH4	70	70	70.5	0.5 - 0.6
TH5	70	73	73	-0.1
TH6	70	73	73	-0.2
WHS1	70	77	77	0.0
KT1	70	70	71	1.3
KT2	70	64-65	67	2.5 - 2.7
KT3	70	64	68	3.8
NWP1	70	71	73 - 75	2.6 - 4.1
NWP2	70	70	70 - 71	0.5 – 0.6
KLHSW	70	65-66	65 - 66	0.0

Notes: Bold figure denotes the noise exceedance which is over the relevant EIAO-TM noise criteria.

It can be seen from the above tables that the predicted differences between with and without the Project are equal to or greater than 1.0dB(A) at a lot of the representative NSRs (as highlighted in grey) which are considered as significant impact from the proposed connecting roads.

Scenario (2)

The roads proposed under the Project are scheduled to open in 2018. According to the projection of the traffic impact assessment, the year with maximum traffic flow within a 15-year period upon commencement of operation of the Project is determined to be 2033. Therefore, the traffic data for year 2033 has been adopted for the assessment. The potential unmitigated road traffic noise impacts on the NSRs for the Project at Year 2033 (AM) due to operation of the Proposed Connecting Road and existing roads network nearby are summarised in Table 4.37 to Table 4.40 below. Detailed breakdown of road traffic noise is shown in Appendix 4.8.

Table 4.37 Unmitigated Road Traffic Noise Impact in Year 2033 near Lin Ma Hang to Wo Keng Shan (Existing Uses)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)	Significant Contribution from New Roads*	No. of Floors exceeded the Noise Criteria	Assumed No. of Dwellings per floor	No. of Dwellings Affected
TYH	70	62	Yes	N/A	N/A	N/A
V1	70	70	Yes	N/A	N/A	N/A
V2	70	65	Yes	N/A	N/A	N/A
CY3	70	61 – 62	Yes	N/A	N/A	N/A
KL1	70	64	Yes	N/A	N/A	N/A
TKL1	70	66	No	N/A	N/A	N/A
TKL2	70	69	No	N/A	N/A	N/A
KTW1	70	64 - 65	Yes	N/A	N/A	N/A
KTW2	70	60	Yes	N/A	N/A	N/A
KTW3	70	67 – 68	Yes	N/A	N/A	N/A
KTW4	70	59	Yes	N/A	N/A	N/A
KTW5	70	66 – 67	Yes	N/A	N/A	N/A
NYH1	70	66 – 67	Yes	N/A	N/A	N/A
NYH2	70	66	Yes	N/A	N/A	N/A
PY1	70	73 – 74	Yes	2	1	2
PY2	70	73	Yes	2	1	2
PY3	70	68 - 69	Yes	N/A	N/A	N/A
PY4	70	71	Yes	1	1	1
PY5	70	67	Yes	N/A	N/A	N/A
PY6	70	68	Yes	N/A	N/A	N/A
PY7	70	66 - 67	Yes	N/A	N/A	N/A
WKS1	70	72	Yes	1	1	1
WKS2	70	67 - 68	Yes	N/A	N/A	N/A
WKS3	70	65 - 66	Yes	N/A	N/A	N/A
WKS4	70	71	Yes	1	1	1
WKS5	70	69	Yes	N/A	N/A	N/A
WKS6	70	69	Yes	N/A	N/A	N/A
WKS7	70	71	Yes	1	1	1

Notes: (*) Significant Contribution from New Roads denotes the noise level from new roads to the overall noise level is equal to or higher than 1.0dB(A)

Table 4.38 Unmitigated Road Traffic Noise Impact in Year 2033 near Lin Ma Hang to Wo Keng Shan (Planned Uses)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)	Significant Contribution from New Roads*	No. of Floors exceeded the Noise Criteria
KTW6	70	67 - 68	No	N/A
WKS8	70	69 - 70	Yes	N/A

Notes: (*) Significant Contribution from New Roads denotes the noise level from new roads to the overall noise level is equal to or higher than 1.0dB(A)

Table 4.39 Unmitigated Road Traffic Noise Impact in Year 2033 near Sha Tau Kok Road Section (Existing Uses)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)	Significant Contribution from New Roads*	No. of Floors exceeded the Noise Criteria	Assumed No. of Dwellings per floor	No. of Dwellings Affected
ST1	70	65 – 68	Yes	N/A	N/A	N/A
ST2	70	69 – 70	Yes	N/A	N/A	N/A
ST3	70	70	Yes	N/A	N/A	N/A
ST5	70	74	Yes	2	1	2
ST6	70	72	Yes	2	1	2
TTW1	70	68	Yes	N/A	N/A	N/A
TTW2	70	70	Yes	N/A	N/A	N/A
LT1	70	75 - 76	Yes	2	1	2
LT2	70	72	Yes	3	1	3
LT3	70	75	Yes	2	1	2
LT4	70	72	Yes	3	1	3

Notes: Bold figure denotes the noise exceedance which is over the relevant EIAO-TM noise criteria and the contribution from new roads to the overall noise level is equal to or higher than 1.0dB(A).

(*) Significant Contribution from New Roads denotes the noise level from new roads to the overall noise level is equal to or higher than 1.0dB(A)

Table 4.40 Unmitigated Road Traffic Noise Impact in Year 2033 near Fanling Highway (Existing Uses)

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)	Significant Contribution from New Roads*	No. of Floors exceeded the Noise Criteria	Assumed No. of Dwellings per floor	No. of Dwellings Affected
TH1	70	76	Yes	1	1	1
TH2	70	73	Yes	2	1	2
TH4	70	71	Yes	2	1	2
TH5	70	73	No	N/A	N/A	N/A
TH6	70	74	No	N/A	N/A	N/A
WHS1	70	78	No	N/A	N/A	N/A
KT1	70	72	Yes	1	1	1
KT2	70	68	Yes	N/A	N/A	N/A
KT3	70	69	Yes	N/A	N/A	N/A
NWP1	70	74 - 76	Yes	2	1	2
NWP2	70	71 - 72	No	N/A	N/A	N/A
KLHSW	70	66 - 67	Yes	N/A	N/A	N/A

Notes: Bold figure denotes the noise exceedance which is over the relevant EIAO-TM noise criteria and the contribution from new roads to the overall noise level is equal to or higher than 1.0dB(A).

(*) Significant Contribution from New Roads denotes the noise level from new roads to the overall noise level is equal to or higher than 1.0dB(A).

Table 4.41 summarises the exceedance of road traffic noise criteria with significant contribution from “new roads” for existing uses, including the number of affected dwellings. No exceedance of road traffic noise criteria for planned uses is predicted.

Table 4.41 Summary of Exceedance of Road Traffic Noise Criteria

NSR ID	Noise Criteria L10(1 hr) dB(A)	Predicted Noise Level L10 (1hr) dB(A)	No. of Floors exceeded the Noise Criteria	Assumed No. of Dwellings per floor	No. of Houses Represented	No. of Dwellings Affected
Lin Ma Hang to Wo Keng Shan
PY1	70	73 – 74	2	1	1	2
PY2	70	73	2	1	2	4
PY4	70	71	1	1	2	2
WKS1	70	72	1	1	2	2
WKS4	70	71	1	1	2	2
WKS7	70	71	1	1	2	2
Loi Tung
ST5	70	74	2	1	1	2
ST6	70	72	2	1	2	4
LT1	70	75 - 76	2	1	3	6
LT2	70	72	3	1	2	6
LT3	70	75	2	1	3	6
LT4	70	72	3	1	1	3
Fanling
TH1	70	76	1	1	3	3
TH2	70	73	2	1	2	4
TH4	70	71	2	1	3	6
KT1	70	72	1	1	1	1
NWP1	70	74 - 76	2	1	9	18
Total no. of Dwellings Affected						73

4.5.1.4 Evaluation of Mitigation Measures

Exceedance of noise criteria were found in various sensitive receivers for both existing and planned uses, direct mitigation measures should be proposed. According to the Section 6.1, Annex 13 of EIAO-TM, direct mitigation measures as listed below should be considered and evaluated:

■ Open-textured road surfacing; and

■ Noise barrier/ enclosure

The mitigation measures above are at-source mitigation measures and were further elaborated in the following paragraphs.

Noise mitigation measures starting from direct ones were evaluated. When all practicable at-source mitigation measures have been exhausted, at-receiver mitigation measures would be considered in terms of modification of layout plan and setback requirement for the planned NSRs, and consideration of provision of noise insulation for the existing NSRs where justified and eligible.

Use of low noise road surfacing (LNRS)

The use of noise absorptive paving materials on project roads can theoretically reduce the traffic noise impact. As per the values specified in CRTN, the use of pervious macadam on road surface can reduce the basic noise level by 3.5 dB(A), as compared to that of 1.0dB(A) for common impervious paving.

In accordance with RD/GN/032, the extent of low-noise surfacing has been considered in the unmitigated scenario and will cover the link roads and slip roads, but not the local road sections i.e. the roundabouts at Sha Tau Kok Road and Ping Yeung, Lin Ma Hang Road, Tai Wo Service Roads etc.

Noise barrier/enclosure

In view of practicability, the erection of noise barrier/ semi-enclosure along the new road sections are considered as effective mitigation measures in tackling the road traffic noise impact to sensitive receivers.

4.5.1.5 Mitigated Noise Impact

Existing Uses

As discussed above, direct mitigation measures in form of noise barrier/ enclosure should be considered in order to comply with the noise criteria. The locations of noise barriers proposed for the existing noise sensitive uses are tabulated in Table 4.42 below and shown in Figures 4.20.1 to 4.20.4. Typical cross-sections of the proposed noise barriers are shown in Figure 4.20.5.

Table 4.42 Proposed Location of Noise Barrier for Existing Uses

Location	Chainage	Type of Noise Mitigation Measures	*Height	Length, m	Figure
Ping Yeung	9040 – 9085 (Main Road – North Bound)	Vertical Barrier	0.8m	85	4.20.1
Nga Yiu Ha	166 (Access Road to Ping Yeung ) – 450 (Slip Road – North Bound)	Vertical Barrier	2.5m	152	4.20.1
Wo Keng Shan	8585 – 8500 (Main Road – North Bound)	Vertical Barrier	2m	85	4.20.2
	8500 – 8355 (Main Road – North Bound)	Vertical Barrier	2m above parapet	145	4.20.2
	8180 – 8290 (Main Road – South Bound)	Vertical Barrier	1m above parapet	110	4.20.2
Loi Tung	6488 – 6855 (Main Road – South Bound)	Vertical Barrier	1.5m	367	4.20.3
	6800 – 6855 (Main Road – South Bound)	Vertical Barrier	0.8m	55	4.20.3
	360 (Sha Tau Kok Rd – West Bound) – 380 (Slip Road – South Bound)	Vertical Barrier	2m	108	4.20.3
	195 (Wo Keng Shan Rd) – 400 (Sha Tau Kok Rd – East Bound)	Vertical Barrier	1.5m	182	4.20.3
	40 (Sha Tau Kok Rd ) – 400 (Slip Road – North Bound)	Vertical Barrier	5m	120	4.20.3
Tong Hang	1640 – 1713 (Main Road – South Bound)	Vertical Barrier	3m	73	4.20.4
	1589 – 1621 (Main Road – South Bound)	Vertical Barrier	3m	32	4.20.4
	0 – 100 (Link Road 4)	Vertical Barrier	4m above parapet	100	4.20.4
	285 – 330 (Access to Main Road South Bound)	Vertical Barrier	5m	45	4.20.4
Wo Hop Shek	185 – 430 (Fanling Highway South Bound connecting Link Road 2)	Vertical Barrier	3m	245	4.20.4
Nam Wan Po	543 – 662 (Link Road 1)	Vertical Barrier	2.5m above parapet	119	4.20.4
	662 - 700 (Link Road 1)	Vertical Barrier	1m	38	4.20.4
	815 – 856 (Link Road 4)	Vertical Barrier	1m above parapet	41	4.20.4
	276 – 336 (Tai Wo Service Road West)	Vertical Barrier	3m above parapet	60	4.20.4
	274 – 175 (Tai Wo Service Road West)	Vertical Barrier	3m above parapet	99	4.20.4

Notes: (*) The parapet wall is 0.8m high above road surface

With the erection of noise barriers, the predicted noise levels are shown in Table 4.43. The detailed breakdowns for road traffic noise are shown in Appendix 4.9.

Table 4.43: Mitigated Road Traffic Noise Levels of Existing Uses

NSR ID	Noise Criteria L10(1 hr) dB(A)	Mitigated Noise Level L10 (1hr) dB(A)
Lin Ma Hang to Wo Keng Shan
PY1	70	68 – 69
PY2	70	67 – 70
PY4	70	68
WKS1	70	68
WKS4	70	70
WKS7	70	70
Loi Tung
ST5	70	68 – 70
ST6	70	67 – 68
LT1	70	68 – 69
LT2	70	70
LT3	70	69 – 70
LT4	70	68 – 70
Fanling
TH1	70	65
TH2	70	69 - 70
TH4	70	70
KT1	70	68
NWP1	70	68 - 70

Notes: (*) Significant Contribution from New Roads denotes the noise level from new roads to the overall noise level is equal to or higher than 1.0dB(A).

Based on the tables above, although some of the NSRs i.e. WHS1, TH5, TH6 and NWP2 would exceed the relevant noise criteria, the noise contribution from new roads is smaller than 1.0 dB(A). Therefore, no further mitigation measure is considered.

Planned Uses

It is noted that the construction of New Territories Exempted House is permitted in V zone within the assessment area. However, as no exceedance of road traffic noise criteria is predicted for such planned uses, no further mitigation measures is required.

4.5.2 Fixed Plant Noise

4.5.2.1 Identification of Emission Source

Potential noise impacts from operation of planned fixed plant including any noisy facilities inside the BCP and ventilation shafts of the tunnel sections of the connecting road on the nearby NSRs have been assessed quantitatively. In accordance with Annex 5 of the EIAO-TM, the noise criteria for fixed plant noise assessment shall be either

■ 5 dB(A) below the appropriate Acceptable Noise Levels (ANL) shown in Table 2 of the Technical Memorandum for the Assessment of Noise from Places Other than Domestic Premises, Public Places or Construction Sites, or

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

For the potential noise impact from the operation of the BCP other than the inside fixed plant sources, discussion is given in Section 4.5.2.5.

Given that the Project will be developed in a quiet rural environment except the area near Fanling Highway, background noise measurements were carried out for comparison with the ANL in establishing the noise criteria (see Section 4.3.1.3). The noise criteria of the fixed plant noise at different locations of the Project are summarised in Table 4.44 below.

Table 4.44 Noise Criteria of Fixed Plant Noise

Location Description	Representative NSR ID.	ASR	Time Period	ANL – 5, dB(A)	Corrected Facade Noise Level, dB(A)*	Fixed Plant Noise Criteria, dB(A)
Tsung Yuen Ha	TYH, V1, V2, CY3	A	Daytime	55	52	52
			Evening Time	55	49	49
			Night-time	45	45	45
Ng Chau Road	WKS6, WKS7	A	Daytime	55	56	55
			Evening Time	55	52	52
			Night-time	45	46	45
Wo Keng Shan	ST1, ST2, ST3 and TTW2	A	Daytime	55	54	54
			Evening Time	55	47	47
			Night-time	45	45	45
Loi Tung	LT4	A	Daytime	55	49	49
			Evening Time	55	44	44
			Night-time	45	43	43
Po Kat Tsai	PKT1, PKT2 and PKT3	A	Daytime	55	46	46
			Evening Time	55	36	36
			Night-time	45	36	36
Fanling Highway	TH1, TH4	C	Daytime	65	N/A	65
			Evening Time	65	N/A	65
			Night-time	55	N/A	55

Notes: (*) A facade correction of 3dB(A) has been included in the measurement results.

4.5.2.2 Assessment Methodology

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 have been determined 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)

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 of the noise criteria until all corrected SPLs at the representative NSRs meet the noise criteria. The maximum allowable SWLs of the proposed fixed plants have been predicted by this approach.

4.5.2.3 Evaluation of Impacts

Noise from fixed plant for the Project would mainly be associated with BCP buildings, tunnel ventilation shaft, administration building and mid-ventilation building. According to the preliminary design information, major fixed plant noise is attributed to the following sources as summarised in Table 4.45 below and shown in Figures 4.21.1 to 4.21.7: -

¡ BCP Buildings;

¡ Ventilation Shafts in Tunnel Portals;

¡ Mid-ventilation Building at Po Kat Tsai; and

¡ Administration Building at Loi Tung.

Table 4.45: Summary of Fixed Plant Noise Sources

Fixed Plant Location	Fixed Noise Source	Number of Fixed Plant	Opening ID	Figure
BCP	Sewage Treatment Plant (G/F)	7	STP-A to G	4.21.1 (1)
	Fixed X-Ray Inspection Station and Offices (G/F)	4	FXO-A to D	4.21.1 (1)
	Fixed X-Ray Inspection Station (G/F)	4	FXI-A to D	4.21.1 (1)
	Passenger Terminal Building (G/F)	4	PTB-A to D	4.21.1 (1)
	Passenger Terminal Building (1/F - 4/F)	4	PTB-A to D	4.21.1 (2)
	Fire Station (G/F)	4	FS-A to D	4.21.1 (1)
	Police Station (G/F)	4	HKP-A to D	4.21.1 (1)
North Tunnel North Portal	Ventilation Building (G/F)	2	VB1-A-B	4.21.2
North Tunnel South Portal & Administration Building at Loi Tung	Ventilation Building (G/F)	2	VB2-A-B	4.21.3
	Administration Building (G/F)	3	AB-A-C	4.21.4
South Tunnel North Portal	Ventilation Building (G/F)	2	VB3-A-B	4.21.5
South Tunnel South Portal	Ventilation Building (G/F)	2	VB4-A-B	4.21.7
Po Kat Tsai	Mid-Ventilation Building (G/F)	1	MVB-A	4.21.6

Based on the methodology mentioned above, the maximum allowable SWLs of the proposed fixed plants during daytime and night-time are predicted as summarized in Table 4.46 below. Calculations of fixed plant noise assessment are shown in Appendix 4.10.

Table 4.46: Maximum SWLs of the Fixed Plant

Fixed Plant Location	Fixed Noise Source	Opening ID	*Maximum SWL, dB(A)
			Daytime	Evening Time	Night-time
BCP	Sewage Treatment Plant (G/F)	STP-A to G	94	91	87
	Fixed X-Ray Inspection Station and Offices (G/F)	FXO-A to D	94	91	87
	Fixed X-Ray Inspection Station (G/F)	FXI-A to D	88	85	81
	Passenger Terminal Building (G/F)	PTB-A to D	90	87	83
	Passenger Terminal Building (1/F - 4/F)	PTB-A to D	90	87	83
	Fire Station (G/F)	FS-A to D	88	85	81
	Police Station (G/F)	HKP-A to D	88	85	81
North Tunnel North Portal	Ventilation Building	VB1-A	102	99	92
		VB1-B	107	104	97
North Tunnel South Portal & Administration Building at Loi Tung	Ventilation Building	VB2-A	107	100	98
		VB2-B	107	100	98
	Administration Building	AB-A	95	88	86
		AB-B	95	88	86
		AB-C	94	87	85
South Tunnel North Portal	Ventilation Building	VB3-A	107	102	101
		VB3-B	107	102	101
South Tunnel South Portal	Ventilation Building	VB4-A	115	115	105
		VB4-B	110	110	100
Po Kat Tsai	Mid-Ventilation Building	MVB-A	98	88	88

Notes: (*) Maximum SWL at each opening

4.5.2.4 Mitigation of Adverse Environmental Impact

With the fixed plant properly designed to meet the maximum SWL listed in Table 4.46, 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.

4.5.2.5 Potential Noise Impact from the Operation of the BCP

Other than the fixed plant sources inside BCP, potential noise impact may be generated from the daily operation of the BCP. The main activities that would be involved in the daily operation include vehicles moving in and out of the BCP with relatively low speed and vehicles lining up inside the BCP for inspection i.e. vehicles in idling. Public address system would be installed inside the BCP but the usage of the system shall be limited as the BCP would be operated mainly by sign gantry. The closest noise sensitive receiver to the BCP i.e. the Tsung Yuen Ha Village is located at a distance of about 75m. Given the nature of the operation within the BCP and the buffer distance to the nearest NSR, it is anticipated that the potential noise impact from the operation within the BCP shall be minimal.

4.6 Environmental Monitoring and Audit

4.6.1 Construction Phase

With the recommended mitigation measures, no residual noise impacts are predicted at all representative NSRs during the construction phase,, However, environmental monitoring and audit (EM&A) is recommended to ensure the mitigation measures and good site practice have been implemented properly, and to minimize the potential noise impact during the construction phase. Details are given in the EM&A Manual.

4.6.2 Operational Phase

Prior to the operation phase of the Project, a commissioning test should be conducted for all major fixed noise sources to ensure compliance of the operational airborne noise levels with the EIAO-TM noise criteria.

Road traffic noise levels should be monitored at representative NSRs, which are in the vicinity of the recommended direct noise mitigation measures, during the first year after road opening.

Details of the EM&A programme are provided in the stand-alone EM&A Manual

4.7 Conclusion

4.7.1 Construction Phase

The noise impact associated with unmitigated construction activities for the proposed BCP and the connecting road would cause exceedance of the daytime construction noise criterion at the nearby NSRs during the normal working hours. Therefore, good site practices and mitigation measures including the use of quiet plants, erection of movable noise barriers and noise insulating fabric have been proposed to alleviate the noise impact. With the good site practices and mitigation measures in place, no residual impacts are predicted at all the NSRs.

4.7.2 Operational Phase

The assessment has predicted that the traffic noise impact arising from the proposed connecting roads of the Project and the contribution from existing road network in Year 2033 will exceed the noise criteria at the existing NSRs with around 76 dwellings affected by the Project roads. With the implementation of mitigation measures recommended, the noise criteria will be met at all representative NSRs with traffic noise impact dominated by the Project roads.

With the specification of maximum allowable sound power levels for the proposed fixed plants at ventilation shafts, mid-ventilation building, BCP buildings and Administration Buildings, full compliance of Noise Control Ordinance will be achieved.

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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 (Table 8-7).

[3] Transit noise and vibration impact assessment, US Federal Transit Administration (FTA), 2006