Table of Contents

4. NOISE IMPACT.. 4-1

4.1 Introduction. 4-1

4.2 Environmental Legislation, Standards and Guidelines. 4-1

4.3 Description of the Environment 4-3

4.4 Noise Sensitive Receivers (NSRs) 4-3

4.5 Assessment Methodology. 4-5

4.6 Identification of Environmental Impacts. 4-8

4.7 Prediction and Evaluation of Environmental Impacts. 4-8

4.8 Mitigation of Adverse Environmental Impacts. 4-10

4.9 Evaluation of Residual Impacts. 4-19

4.10 Environmental Monitoring and Audit 4-20

4.11 Conclusion. 4-20

LIST OF TABLES

Table 4‑1 Basic Noise Levels for ANLs. 4-2

Table 4‑2 Construction Noise Standards during Non-restricting Hours. 4-2

Table 4‑3 Road Traffic Noise Assessment Criteria Specified in the EIAO-TM... 4-3

Table 4‑4 Identified Representative Noise Sensitive Receivers. 4-4

Table 4‑5 Road Types of the Project Roads. 4-6

Table 4‑6 Maximum Noise Levels (dB(A)) during Construction without Noise Mitigation Measures 4-9

Table 4‑7 Predicted Road Traffic Noise Levels at Each Identified NSR under the Unmitigated Scenario 4-10

Table 4‑8 Maximum SWLs for Selected “Quiet” PME and Alternative Plants. 4-11

Table 4‑9 Noise Mitigation Measures for Certain PME during Construction Phase. 4-12

Table 4‑10 Maximum Noise Levels (dB(A)) during Construction with Noise Mitigation Measures Adopted 4-14

Table 4‑11 Summary of Proposed Noise Mitigation Measures. 4-16

Table 4‑12 Predicted Road Traffic Noise Levels at Each Identified NSR under the Mitigated Scenario 4-17

Table 4-13 Total Number of Dwellings, Classrooms and Other Noise Sensitive Elements that will be Benefitted from and be Protected by Provision of the Direct Noise Mitigation Measures. 4-18

Table 4‑14 Predicted Residual Construction Noise Period during Examination Period. 4-19

LIST OF FIGURES

Figure 4.1 Project Boundary, 300m Study Boundary, and Locations of Noise Sensitive Receivers

Figure 4.2 Locations of Assessment Points of Each NSR (Key Plan, Sheets 1 and 2)

Figure 4.3 Locations of Construction Work areas and Noise Assessment Points

Figure 4.4A Proposed Locations of Noise Mitigation Measures

Figure 4.4B Section Views of Proposed Vertical and Cantilevered Barriers

APPENDICES

Appendix 4-1 Photographs of Identified Noise Sensitive Receivers

Appendix 4-2 Traffic Forecast for Assessment Year 2036

Appendix 4-3 Endorsement Letter from Traffic Department regarding Traffic Forecast

Appendix 4-4 Correspondence with Highways Department regarding Existing or Planned Noise Mitigation Measures

Appendix 4-5 Road-Plots of Road Traffic Noise Model

Appendix 4-6 Correspondence for the Concurrent Project - Replacement and Rehabilitation of Water Mains Stage 4

Appendix 4-7 Detailed Construction Noise Calculations (Unmitigated Scenario)

Appendix 4-8 Detailed Predicted Road Traffic Noise Results at Each Noise Assessment Point under the Unmitigated Scenario

Appendix 4-9 Detailed Construction Noise Calculations (Mitigated Scenario)

Appendix 4-10 Detailed Predicted Road Traffic Noise Results at Each Noise Assessment Point under the Mitigated Scenario

4. NOISE IMPACT

4.1 Introduction

4.1.1 This section presents the assessment of potential noise impact associated with the construction and operation phases of the Project. During the operation phase, noise sensitive receivers within 300m of the project boundary have been identified and the noise impact on these receivers has been assessed in detail. Noise mitigation measures, where necessary, have been recommended accordingly to reduce the identified noise impacts to acceptable levels.

4.1.2 Since the Project does not include fixed noise sources such as ventilation systems of tunnels or other ‘fixed plants’, noise impact generated by fixed noise sources is not anticipated. Noise impact during the operational phase is mainly contributed by road traffic noise.

4.2 Environmental Legislation, Standards and Guidelines

Construction Phase

4.2.1 In Hong Kong, control of construction noise is carried out under the Noise Control Ordinance (NCO) and the two subsidiary Technical Memoranda on Noise from Percussive Piling (PP-TM) and Noise from Construction Work Other Than Percussive Piling (GW-TM). Construction Noise Permit (CNP) is required for carrying out percussive piling at daytime on any day not being a general holiday and for carrying out general construction works during restricted hours (i.e. 1900 to 0700 hours on a day not being a general holiday and at any time on a general holiday).

4.2.2 An additional technical memorandum, the Technical Memorandum on Noise from Construction Work in Designated Areas (DA-TM), deals with the control of noise generated by Specified Powered Mechanical Equipment (SPME) and Prescribed Construction Works (PCWs) in designated areas. SPME includes hand-held breaker, bulldozer, concrete lorry mixer, dump truck and hand-held poker, vibratory; PCWs include erection/dismantling of formwork/scaffolding, loading/unloading or handling of rubble, wooden boards, steel bars, wood or scaffolding material, and hammering.

Percussive Piling

4.2.3 Percussive piling is prohibited during restricted hours, i.e. 1900 to 0700 hours on any day not being a general holiday and at any time on a general holiday. A CNP, under the NCO, is required for percussive piling works during non-restricted hours, i.e. between 0700 and 1900 hours on any day not being a general holiday. The PP-TM is used in examining the application of a CNP for percussive piling during non-restricted hours.

General Construction Works (other than Percussive Piling) during restricted hours

4.2.4 For construction activities (other than percussive piling) taking place within restricted hours, i.e. 1900 to 0700 hours on any day not being a general holiday and at any time on a general holiday, a CNP, under the NCO, is required.

4.2.5 The GW-TM is used in examining the application of a CNP for general construction works other than percussive piling during restricted hours. The Noise Control Authority (NCA) may issues a CNP if the Corrected Noise Levels (CNLs), taking into account the correction factors such as acoustic reflections etc., are not greater than the Acceptable Noise Levels (ANLs) as stated in the GW-TM. The ANLs, depending on the Area Sensitivity Rating (ASR) of the NSRs, are defined in GW-TM and are presented below in Table 4‑1.

Table 4‑1 Basic Noise Levels for ANLs

Time Period	ASR
	A	B	C
All days during the evening (1900 to 2300 hours), and general holidays (including Sundays) during the daytime and evening (0700 to 2300 hours)	60	65	70
All days during the night-time (2300 to 0700 hours)	45	50	55

4.2.6 It is the Contractor’s responsibility to ensure compliance with the NCO and the relevant TMs in case of any construction activities during restricted hours. There is no guarantee that a CNP will be issued for the project construction. The NCA will consider a well justified CNP application, once filed, for construction work within restricted hours as guided by the relevant TMs issued under the NCO. The NCA will take into account of contemporary conditions / situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP. Nothing in this EIA shall bind the NCA in making his decision. If a CNP is to be issued, the NCA shall include in it any condition he thinks fit. Failure to comply with any such conditions will lead to cancellation of the CNP and prosecution action under the NCO.

General Construction Works (other than Percussive Piling) during non-restricted hours

4.2.7 For construction activities outside restricted hours, the “Technical Memorandum on Environmental Impact Assessment Process” (EIAO-TM) stipulates noise standards as shown Table 4‑2.

Table 4‑2 Construction Noise Standards during Non-restricting Hours

Uses	Noise Standards ^[1] , Leq (30 mins) dB(A)
	Non-restricted hours: 0700 to 1900 hours on any day not being a Sunday or general holiday	Restricted hours: 1900 to 0700 hours or any time on Sundays or general holiday
All domestic premises including temporary housing accommodation	75	See Note ^[2]
Hotels and hostels	75
Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required	70 65 (During examinations)

Notes:

^[1] The above standards apply to uses that rely on opened windows for ventilation.

^[2] The criteria laid down in the relevant technical memoranda under the NCO for designated areas and construction works other than percussive piling may be used for planning purpose. A CNP shall be required for the carrying out construction work during the period.

Operation Phase - Road Traffic Noise

4.2.8 Road traffic noise criteria are listed in Table 1A, Annex 5 of the EIAO-TM, which provides guidance on acceptable road traffic noise levels at various types of noise sensitive buildings. The relevant criteria are shown in Table 4‑3. These standards apply to uses which rely on opened windows for ventilation.

Table 4‑3 Road Traffic Noise Assessment Criteria Specified in the EIAO-TM

Uses	Road Traffic Noise Assessment Criteria – Peak Hour Traffic (L10,(1-hour)) / dB(A)
Domestic Premises	70
Hotels and Hostels	70
Offices	70
Educational Institutions	65
Places of public worship and courts of law	65
Diagnostic rooms and wards of hospitals, clinics, convalescences and homes for the aged	55

4.3 Description of the Environment

4.3.1 The existing land uses in the vicinity of the project site are mainly residential, commercial, and educational uses. Road traffic noise in the area is mainly emanated from Tsing Kwai Highway, Kwai Chung Road, and Tsuen Wan Road.

4.4 Noise Sensitive Receivers (NSRs)

4.4.1 For operational noise impact assessment, a spatial scope of 300m from the proposed Project Boundary has been included as the Study Area.

4.4.2 NSRs have been identified in accordance with Annexes 5 and 13 of the EIAO-TM which can include domestic premises, temporary housing accommodation, educational institutions, nurseries, hospitals, medical clinics, homes for the aged, convalescent homes, places of public worship, libraries, courts of law, performing arts centres, having direct line-of-sight and substantial angle of view to the Project Area. Sensitive receivers present within the 300m study area boundary have been identified. Relevant land uses were identified on the corresponding Outline Zoning Plans and no planned noise sensitive receivers were identified.

4.4.3 For the purpose of noise assessment, the first layer of noise sensitive receivers located closest to the project boundary within the 300m study area, and with direct line of sight to the Project, have been selected as representative NSRs for noise prediction and evaluation.

4.4.4 Figure 4.1 illustrates the project boundary and 300m study area boundary together with the identified representative NSRs whereas noise assessment points at each identified NSR are demonstrated in Figure 4.2. Details for the identified NSRs are summarized in Table 4‑4. Photographs of the identified NSRs are shown in Appendix 4-1.

Table 4‑4 Identified Representative Noise Sensitive Receivers

NSR ID	Property Name	Land Use	Ground Level (mPD)	No. of Noise Sensitive Storeys	1st Floor Assess-ment Point (mPD)	Assessment for Construction Phase/ Operational Phase #	Notes
NSR1	New Kwai Fong Gardens Block A	Residential	6.7	32	22.4	O
NSR2	Lingnam Dr. Chung Wing Kong Memorial Secondary School	Educational Institution	5.4	6	9.6	C,O	*
NSR3	Lai King Catholic Secondary School	Educational Institution	5.4	6	9.6	C,O	*
NSR4	Ha Kwai Chung Polyclinic and Special Services Centre	Clinic	27.8	6	29.0	C,O	*
NSR5	Fung King House	Residential	15.3	14	19.3	C,O
NSR6	Wo King House	Residential	15.3	14	19.3	C,O
NSR7	Ming King House	Residential	27.4	15	31.4	C,O
NSR8	Yat King House	Residential	27.4	23	31.4	C,O
NSR9	HKEAA-Lai King Assessment Centre	Educational Institution	30.1	6	37.3	C,O	*
NSR10	Yin Lai Court - Yin Kwong House (Block A)	Residential	34	35	39.2	C,O
NSR11	Yin Lai Court - Yin Tak House (Block B)	Residential	34	35	39.2	C,O
NSR12	Yuet Lai Court - Lai Hung House	Residential	59.7	22	63.8	O
NSR13	Yuet Lai Court - Lai Ha House	Residential	62.6	22	63.8	O
NSR14	Yuet Lai Court - Lai Wah House	Residential	62.6	22	63.8	O
NSR15	Yuet Lai Court - Lai Wan House	Residential	62.9	22	63.8	O
NSR16	Yeung King House (Block 5)	Residential	25.8	15	29.8	O
NSR17	On King House (Block 6)	Residential	25.8	14	29.8	O
NSR18	Clothing Industry Training Centre	Educational Institution	40.1	6	44.3	O	*

Notes:

# C = Construction Phase, O = Operation Phase

* Air-conditioning systems were noted on site

4.4.5 According to site observations, window-type air-conditioners or central air conditioning system have been installed at Lingnam Dr. Chung Wing Kong Memorial Secondary School (NSR2), Lai King Catholic Secondary School (NSR3), Ha Kwai Chung Polyclinic and Special Services Centre (NSR4), HKEAA-Lai King Assessment Centre (NSR9) and Clothing Industry Training Centre (NSR18).

4.4.6 Notwithstanding the provision of air conditioners at these NSRs (NSR 2, 3, 4, 9, 18), it is also possible for these sites to rely on opened window for ventilation. Therefore, these sites are still considered as NSRs for noise impact assessment.

4.5 Assessment Methodology

Constructional Phase

4.5.1 Methodology for assessing noise from the construction activities associated with the proposed works is developed based on the GW-TM and is summarised as follows:

· Location of appropriate NSRs with respect to the work sites;

· Determination of distance attenuation and screening effects to NSRs from notional noise source of relevant work sites;

· Prediction of construction noise levels at NSRs in the absence of any mitigation measures;

· Proposal of mitigation measures and determination of their effectiveness; and

· Determination of the residual impacts.

4.5.2 Various construction work activities will not take place concurrently despite being in the same work task, e.g. excavation, namely Activity 1 (“Act 1”), and concreting, namely Activity 2 (“Act 2”) for the task of bored piles construction. The activity with maximum noise level within the same work task is considered in construction noise evaluation. In order to provide a realistic assessment, the percentages of powered mechanical equipment (PME) operation on site have also been considered when calculating the cumulative Sound Power Levels (SWL) for the construction activities. Construction noise levels at the NSRs have been assessed on a monthly basis with respect to the individual noise levels induced by the construction work tasks.

4.5.3 Potential construction noise impact is anticipated tentatively from year 2018 to year 2021. The assessment of noise impact during daytime general construction works, excluding percussive piling, between 0700 and 1900 hours on weekdays, i.e. non-restricted hours as defined in NCO, will follow Table 1B of EIAO-TM noise standards, which are L_Aeq(30-min) 75 dB(A) for domestic premises, hotels and hostels; and L_Aeq(30-min) 70 dB(A) for educational institutions during normal hours, and L_Aeq(30-min) 65 dB(A) during examination periods. There is no applicable standard under EIAO-TM for clinic (Ha Kwai Chung Polyclinic and Special Services Centre). Reference is made to Table 1B of EIAO-TM noise standard for “Education institutions including kindergartens, nurseries and all others where unaided voice communication is required” for these uses, and the noise assessment criteria is taken to be L_Aeq(30-min) 70dB(A). These standards apply to uses which rely on opened windows for ventilation.

4.5.4 In general, the current construction program has been formulated such that no work will be required in restricted hours as defined under NCO. However, due to traffic safety, the lifting of the footbridge truss in the demolition and reprovision of the footbridge, with the use of a mobile crane and lorry, as well as stitch joint installation in the construction of Bridge G and Bridge H, would be required to be carried out during restricted hours under NCO. For construction activities (other than percussive piling) taking place within restricted hours, i.e. 1900 to 0700 hours on any day not being a general holiday and at any time on a general holiday, a CNP, under the NCO, is required.

Operational Phase

4.5.5 The computer model RoadNoise 2000 was used to predict the traffic noise levels. This model adopts the methodology of “Calculation of Road Traffic Noise (CRTN)” (1988) published by the UK Department of Transport. CRTN takes into account all major parameters related to effective traffic noise prediction, including traffic flow and composition, road segment length and gradient, road surface, propagation characteristics, barrier and façade effects, as well as site layout settings etc. The road traffic noise are presented in terms of noise levels exceeded for 10% of the one-hour period for the hour having the peak traffic flow (L_10(1-hour) dB(A)).

4.5.6 Calculations of predicted road traffic noise have been based on the peak hour flows projected within a 15-year period upon commencement of operation, year 2021. For worst-case scenario evaluation, the assessment year was chosen to be year 2036, corresponding to the year with the maximum projected peak hour traffic flow within 15 years from commencement of operation. The peak flow of traffic within the study area would be at 0800 to 0900.

4.5.7 The traffic forecast at the peak hour (0800-0900) was provided by the Project Traffic Consultant and have been submitted to Transport Department for approval. The peak hour traffic flows at assessment year 2036 is shown in Appendix 4-2 while the agreement letter from Transport Department on the use of the projected traffic data for this study is attached in Appendix 4-3.

4.5.8 For the purpose of the road traffic noise assessment, the roads within 300m from the proposed road alignments of the Project are included in the assessment. All roads are described as one of the following:

· “Designated Project (DP) Roads” are the roads that are completely new or existing road sections that have major modifications and would cause significant traffic noise impact.

· “Other Roads” are the roads that are unchanged or subject to minor changes by the Project or roads that not classified as a material change under the Project.

4.5.9 As mentioned in Section 1, there are two main parts to the Project, summarised in Table 4‑5, with locations shown in Figure 4.1.

Table 4‑5 Road Types of the Project Roads

Project Section	Road Description	Road Type
Bridge G	Minor widening of Tsuen Wan Road Flyover near existing Kwai Tsing Interchange Upramp	Trunk road
Bridge H	A new single lane flyover with 6.0m width from Tsuen Wan Road (southbound- fast lane) to Kwai Chung Road	Trunk road

4.5.10 The work on Bridge G involves minor widening of the bridge deck of the Tsuen Wan Road Flyover. This represents a short section of the road where the nature and the traffic composition of the road would not be changed, i.e. total number of traffic lanes would not be increased. As mentioned in Section 1.2.2, traffic flow on Bridge G would be reduced because part of the traffic would be diverted to Bridge H, the traffic noise impact from Bridge G would be considered insignificant in view of the traffic noise level with the minor widening work from Bridge G would be less than that without the minor widening works. Therefore, Bridge G is not included in the DP roads and is classified as "Other Roads" in the operation noise assessment.

4.5.11 Bridge H is a designated project (DP) as it is a new bridge with more than 100m in length between abutments in accordance to Item A.8 of Schedule 2 of the EIAO. It is therefore classified as a “DP Road” for the purposes of noise assessment.

4.5.12 In this regard, for the purposes of this noise impact assessment, only Bridge H is considered to be a “DP Road”. “Other Roads” include Bridge G and all existing roads.

4.5.13 Existing noise mitigation measures include noise barriers on Tsing Kwai Highway and Kwai Chung Road, and low noise road surfacing (LNRS) on portions of Tsing Kwai Highway, Kwai Chung Road and Tsuen Wan Road were identified and adopted in the traffic noise model. The locations of these noise mitigation measures and relevant correspondence with the Highways Department (HyD) can be found in Appendix 4-4.

4.5.14 Appendix 4-5 shows the road plot of the traffic noise model which incorporated identified existing mitigation measures by HyD as well as recommended mitigation measures for the Project.

4.5.15 The following scenarios for traffic noise prediction model are presented:

· Unmitigated scenario at assessment year (2036); and

· Mitigated scenario at assessment year (2036)

4.5.16 In accordance with Annex 5 and Annex 13 of the EIAO-TM and the EIA study brief, direct noise mitigation measures would be proposed for the DP Roads if there would be an adverse environmental impact. If exceedance of the relevant road traffic noise criteria is predicted and is contributed significantly by the DP Roads, direct mitigation measures are required to reduce the noise from the DP Roads to a level which:

· Is not higher than the noise criteria; and

· Has no significant contribution to the overall noise from Other Roads, if the cumulative noise level (i.e. noise from the DP Roads together with Other Roads) exceeds the noise criteria

4.5.17 In cases where direct noise mitigation measures alone are not adequate in mitigating noise to a level in compliance with the EIAO-TM noise criteria, indirect technical remedies for existing NSRs may be adopted. Eligibility of the affected premises for indirect technical remedies is determined with reference to the following three criteria, all of which must be satisfied:

(a) The predicted overall noise level exceeds the noise standard in accordance with EIAO-TM (e.g. 70 dB(A) for domestic premises and 65 dB(A) for educational institutions, all in L_10(1hour)); and

(b) The predicted overall noise level is at least 1.0 dB(A) more than the prevailing traffic noise level, i.e. the total traffic noise level existing before the works to construct the road were commenced; and

(c) The contribution from the DP Roads to the increase in the predicted overall noise level is at least 1.0 dB(A).

4.6 Identification of Environmental Impacts

Construction Noise

4.6.1 The potential sources of noise impact during the construction phase of the Project would be the use of PME for various construction activities. As broadly indicated in the construction program shown in Appendix 2-1, the construction of the project would tentatively start in early 2018 and lasts for about 44 months. Location of works area is also provided in Figure 4.3. The key construction noise activities include:

· Site mobilisation, and preparation (for all Works Areas)

· Construction of Bridge H (within Works Areas D, E & F)

· Noise barrier construction (within Works Areas D, E & F)

· Widening works on Bridge G (within Works Area A)

· Demolition of existing footbridge (within Works Areas D & E)

· Reprovision of footbridge (within Works Areas B & C)

· Relocation/modification of existing bus lay-by (within Works Areas D & E)

· Modification of Kwai Chung Road (outside Fung King House) (within Works Area D)

· Completion of works (for all Works Areas)

4.6.2 Tentative construction period of the Project is from year 2018 to year 2021. Nearby project “Replacement and Rehabilitation of Water Mains Stage 4, Mains in New Territories – Investigation, Design and Construction (Contract No. 11/WSD/11) is anticipated to end at the fourth quarter of 2015 according to the correspondence with the appropriate authorities. Relevant correspondence is provided in Appendix 4-6. Therefore, no concurrent noise impact due to the nearby construction works is anticipated.

Operation Phase

4.6.3 Identified potential operational noise from the project includes road traffic noise from the proposed roads and existing roads. Peak traffic flow in the 300m study area occurs in year 2036 (15 years after the commencement of the Project) at 0800-0900 in the morning, thus the traffic forecast for this time period is used for the prediction of the worst case scenario. A summary of the traffic flow data of 2036 at 0800-0900 can be found in Appendix 4-2.

4.7 Prediction and Evaluation of Environmental Impacts

Construction Phase

4.7.1 The maximum construction noise levels at the representative NSRs during the construction phase of the Project, without noise mitigation applied, are shown in Table 4-6 below. The PME plant inventories and detailed calculations are provided in Appendix 4-7.

Table 4‑6 Maximum Noise Levels (dB(A)) during Construction without Noise Mitigation Measures

NSR	Description	Assessment Criteria, dB(A) ^[2]	Predicted Maximum Noise Levels, dB(A) ^[1]
			2018	2019	2020	2021
NSR2	Lingnam Dr. Chung Wing Kong Memorial Secondary School	70/65	70	70	68	68
NSR3	Lai King Catholic Secondary School	70/65	79	80	75	79
NSR4	Ha Kwai Chung Polyclinic and Special Services Centre ^[3]	70	69	69	68	68
NSR5	Fung King House	75	78	81	79	78
NSR7	Ming King House	75	64	80	79	75
NSR8	Yat King House	75	65	75	73	70
NSR9	HKEAA-Lai King Assessment Centre	70/65	63	77	75	72
NSR10	Wo King House	75	61	71	69	66
NSR11	Ming King House	75	61	70	68	65

Notes:

[1] Predicted noise exceedance are highlighted in bold.

[2] Construction Noise Impact Assessment criteria for educational institutions are L_eq,30min of 65dB(A) during examination period and 70dB(A) during normal school days.

[3] For clinic, construction noise impact assessment criteria are not available with reference to EIAO-TM. L_eq,30min of 70dB(A) is adopted for this study.

4.7.2 Without adopting noise mitigation measures, construction noise impacts at some of the most affected NSRs are predicted to exceed the relevant criterion up to 10dB(A). Feasibility of providing noise reduction measures to minimise construction noise impact has been examined and discussed in the Sections 4.8.1-4.8.12.

Operation Phase

4.7.3 Based on the peak hour traffic flows in assessment year 2036 (peak hour traffic flow within 15 years upon commencement of the Project at the end of year 2021), the unmitigated traffic noise levels after completion of the Project at the representative NSRs were calculated and summarised in Table 4-7. Detailed modelling results at each level of each assessment point of the NSRs and associated calculations are presented in Appendix 4-8, which show that overall predicted noise level are largely contributed by the “Other Roads”, not by the “DP roads”.

4.7.4 Nevertheless, predicted noise levels under unmitigated scenario in Year 2036 due to the “DP roads” only, at some assessment points like NSR3, NSR4, NSR5 and NSR9, would still exceed the EIAO noise criteria. This constitutes non-compliance with the first criteria listed in Section 4.5.16. Therefore, direct noise mitigation measures are deemed necessary to reduce the road traffic noise impact, due to the “DP roads”.

Table 4‑7 Predicted Road Traffic Noise Levels at Each Identified NSR under the Unmitigated Scenario

NSR	Description	Noise Standard Under EIAO-TM, dB(A)	Range of Predicted Noise Level (Unmitigated) (L10(1hour), dB(A))			Direct Mitigation Measures Required? ^[1]
			Overall Noise Level	Predicted Noise Levels due to Other Roads	Predicted Noise Levels due to DP Roads only
NSR1	New Kwai Fong Gardens Block A	70	70~77	70~77	33~56	No
NSR2	Lingnam Dr. Chung Wing Kong Memorial Secondary School	65	72~77	72~77	37~57	No
NSR3	Lai King Catholic Secondary School	65	70~81	70~81	54~66	Yes
NSR4	Ha Kwai Chung Polyclinic and Special Services Centre	55	69~80	69~80	51~60	Yes
NSR5	Fung King House	70	72~84	72~84	62~72	Yes
NSR6	Wo King House	70	57~76	57~76	33~57	No
NSR7	Ming King House	70	57~80	57~80	36~69	No
NSR8	Yat King House	70	55~76	55~76	35~63	No
NSR9	HKEAA-Lai King Assessment Centre	65	77~81	77~81	60~69	Yes
NSR10	Yin Lai Court - Yin Kwong House (Block A)	70	69~78	69~78	37~62	No
NSR11	Yin Lai Court - Yin Tak House (Block B)	70	69~78	69~78	38~61	No
NSR12	Yuet Lai Court - Lai Hung House	70	70~74	70~74	26~38	No
NSR13	Yuet Lai Court - Lai Ha House	70	67~75	67~75	32~49	No
NSR14	Yuet Lai Court - Lai Wah House	70	64~75	64~75	34~49	No
NSR15	Yuet Lai Court - Lai Wan House	70	66~74	66~74	34~48	No
NSR16	Yeung King House (Block 5)	70	74~78	74~78	38~53	No
NSR17	On King House (Block 6)	70	66~78	66~78	26~52	No
NSR18	Clothing Industry Training Centre	65	69~71	69~71	36~40	No

Notes:

^[1] Direct mitigation measures are required if (a) noise level from DP roads only > noise standards under EIAO-TM; or (b) overall noise level> noise standards under EIAO-TM, and difference between overall noise levels and noise levels of Other Roads ≥ 1.0 dB(A)

4.8 Mitigation of Adverse Environmental Impacts

Construction Phase

4.8.1 A number of available construction noise mitigation measures have been considered in this assessment, including:

· selection and optimisation of construction programs, avoidance of parallel operation of noisy PME, and/or reduction in the proportion of usage of PME during noise sensitive periods such as school examination period;

· use of “quiet” PME and working methods;

· use of temporary at-source noise mitigation measures such as noise barriers, acoustic fabric, noise enclosures, noise jacket and mufflers; and

· use of good site practice to limit noise emission from construction site.

Selection and Programming of Construction Processes

4.8.2 The timing and sequencing of the various construction activities shall be carefully arranged according to the actual site work situation, in order to limit the amount of concurrent activities and where applicable, to avoid parallel operation of noisy PME in order to minimize the total noise generated during construction periods. Limiting the quantity of PME to be operated concurrently and also their proportion of usage were recommended in the Project and incorporated in this assessment. The proposed quantity of PMEs and their proportion of usage have been confirmed feasible by the Project Engineer. In the case during school examination when more stringent construction noise criteria should be imposed, the potentially most disruptive construction activities should be avoided, and arranged to be conducted during school holidays as far as practicable.

Use of “Quiet” Alternative Plant and Working Methods

4.8.3 The use of particular plants with equipment noise levels quieter than those specified in the GW-TM can result in reduction of noise levels generated by the plant. The level of noise reduction achieved is dependent on the contractor’s chosen methods of working. It is possible for the contractor to achieve noise reductions from the adopted working methodologies by specifying maximum limits of sound power level for specific plant.

4.8.4 “Quiet” plant is defined as a PME having actual Sound Power Levels (SWLs) lower than the values specified for PME in the GW-TM. SWLs for typical PMEs provided in the GW-TM and that for equivalent “quiet” plants are presented in Table 4‑8.

4.8.5 The type of quiet PMEs adopted in this assessment is for reference only and to be confirmed by the contractors, in view of the actual construction conditions and programs. The contractors are allowed to use other types of quiet PMEs, which have the equivalent total SWLs, to meet their needs.

Table 4‑8 Maximum SWLs for Selected “Quiet” PME and Alternative Plants

Identification Code in GW-TM	Descriptions of PME	SWL in GW-TM, dB(A)	“Quiet” PME example on QPME list ^[1]	SWL of “Quiet” PME, dB(A)
CNP 004	Asphalt Paver	109	EPD-01226 (VOLVO ABG5770)	104
CNP 081	Excavator, Wheeled/Tracked	112	EPD-01896 (HYUNDAI R80CR-9)	98
CNP 048	Mobile Crane	112	EPD-01516 (KOBELCO CKS900)	101
CNP 170	Poker, vibratory, hand held	113	Poker, vibratory, hand held (electric)	102
CNP 185	Road Roller	108	EPD-01806 (KANTO-TK KV25DS)	95

Note:

^[1] QPME list available on the EPD website

Temporary Noise Barriers

4.8.6 The use of 3m high movable barriers can be located about 5m from PMEs. Whilst screening effects can be achieved at upper floors of NSRs, greater benefits result at lower floors where screening is the most effective. These temporary noise barriers will become more effective when located immediately adjacent to the working area, and can reduce the noise level by up to 5 dB(A) and 10 dB(A) for mobile and stationary plants, respectively. 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 of intercepting the line of sight between the NSRs and PME. The minimum surface density of the movable noise barrier is 10 kg/m².

4.8.7 The grab and chisel piling plant is a noisy but stationary piece of equipment. A 8m high movable barrier with skid footing and a small cantilevered upper portion can be located within a few metres of the plant. It is estimated that movable noise barriers of this type can produce 10dB(A) of screening. With reference to Tsim Sha Tsui Station Northern Subway EIA Report, 2008, the use of acoustic fabric can also be considered as an alternative to reduce the noise level.

4.8.8 Depending on site situation, when temporary noise barriers are not practicable or noise reduction achieved is insufficient, noise jacket/muffler can be applied to cover the noisy part of the engine or at the engine exhaust of particular mobile plants respectively. It is assumed that temporary noise barriers of this type can provide screening effect of 5 dB(A) in the assessment.

4.8.9 A summary of the assumed noise reduction effects achieved by temporary noise barrier and acoustic fabric for certain items of PME are provided in Table 4‑9.

Table 4‑9 Noise Mitigation Measures for Certain PME during Construction Phase

Descriptions of PME	Mitigation Measures Proposed	Noise Reduction, dB(A)
Breaker, excavated mounted	Temporary Noise Barrier	5
Excavator/Loader, Wheeled/Tracked	Temporary Noise Barrier	5
Dump Truck, with grab, ≤38 tonne	Temporary Noise Barrier	5
Lorry	Temporary Nosie Barrier	5
Lorry with crane/grab	Temporary Nosie Barrier	5
Mobile Crane	Temporary Nosie Barrier Acoustic Fabric	5
Poker, vibratory, hand-held (electric)	Temporary Nosie Barrier	5
Piling, large diameter bored, grab and chisel	Temporary Noise Barrier^[1]/Acoustic Fabric^[2]	10
Road Roller	Temporary Noise Barrier	5
Concrete Lorry Mixer	Temporary Noise Barrier	5
Saw, chain, hand-held	Temporary Nosie Barrier	5
Concrete pump, lorry mounted	Temporary Nosie Barrier	5
Asphalt Paver	Temporary Noise Barrier	5
Air Compressor	Temporary Noise Barrier	5

Note:

^[1] Temporary Noise Barrier of height not less than the equipment height to be provided to screen noisy part of equipment. It is anticipated that temporary noise barrier of 8m high with skid footing and a small cantilevered upper portion can be located within a few metres of these equipment.

^[2] With reference to Tsim Sha Tsui Station Northern Subway EIA Report, 2008, the use of acoustic fabric can achieve 10dB(A) noise reduction for piling activities .

Good Site Practice

4.8.10 The use of good site practice/techniques can provide considerable reductions in noise emissions. Examples of these site practice include:

· use of well-maintained and regularly-serviced plant during the works;

· plant operating on intermittent basis should be turned off or throttled down when not in active use;

· plant that is known to emit noise strongly in one direction should be orientated to face away from the NSRs;

· silencers, mufflers and enclosures for plant should be used where possible and maintained adequately throughout the works;

· where possible fixed plants should be sited away from NSRs; and

· stockpiles of excavated materials and other structures such as site buildings should be used effectively to screen noise from the works.

Assessment of Noise Impacts with the Application of Mitigation Measures

4.8.11 Construction noise calculations have been carried out with the incorporation of different noise mitigation measures as discussed above, as far as practicable according to the actual construction condition and limitation. Mitigation measures adopted in this assessment include:

· the use of quiet plants for PME (QPME);

· temporary noise barriers and acoustic fabric for PME, as well as noise jacket and mufflers to cover the noisy part of PME and at the engine exhaust of mobile plants respectively;

· limiting of the number of plants operated concurrently.

4.8.12 Construction noise levels at the selected NSRs (which are predicted to be the worst affected by the associated construction works) under the mitigated scenario are summarized in Table 4-10 below. Detailed calculations of the construction noise impact assessment and complete PME inventory are provided in Appendix 4-10.

Table 4‑10 Maximum Noise Levels (dB(A)) during Construction with Noise Mitigation Measures Adopted

NSR	Description	Assessment Criteria, dB(A) ^[2]	Predicted Maximum Noise Levels, dB(A) ^[1]
			2018	2019	2020	2021
NSR2	Lingnam Dr. Chung Wing Kong Memorial Secondary School	70/65	62	61	61	56
NSR3	Lai King Catholic Secondary School	70/65	70	69	68	70
NSR4	Ha Kwai Chung Polyclinic and Special Services Centre ^[3]	70	61	62	61	56
NSR5	Fung King House	75	69	73	71	68
NSR7	Ming King House	75	60	72	70	67
NSR8	Yat King House	75	57	67	65	62
NSR9	HKEAA-Lai King Assessment Centre	70/65	57	69	67	64
NSR10	Wo King House	75	54	63	61	58
NSR11	Ming King House	75	53	61	60	56

Notes:

^[1] Predicted noise exceedance are highlighted in bold.

^[2] Construction Noise Impact Assessment criteria for educational institutions to be L_eq,30min of 65dB(A) during examination period and 70dB(A) during normal school days.

^[3] For clinic, construction noise impact assessment criteria are not available with reference to EIAO-TM. L_eq,30min of 70dB(A) is adopted for this study.

Operation Phase

4.8.13 As stated in Section 6, Annex 13 of the EIAO-TM, there is a range of possible measures available to mitigate road traffic noise. For existing development, these include:

· treatment of source;

· alternative alignment;

· noise barrier/enclosure; and

· open-textured road surfacing (i.e. low noise road surfacing)

4.8.14 In view of practicality, roadside cantilevered and vertical noise barriers are considered to be an effective and practicable mitigation option for road traffic noise impact.

4.8.15 In general, concrete parapet walls of 0.8m or higher are adopted in this operational noise impact assessment along all elevated sections of existing and planned roads, except for the eastern sections of Tsuen Wan Road Flyover.

4.8.16 Direct noise mitigation measures such as vertical and cantilevered noise barriers, as well as semi-enclosures or full noise enclosures and LNRS have been considered for mitigating road traffic noise impact from DP Roads. However, LNRS would be re-provisioned for Bridge G after minor widening works and applied in the noise model as it is a standard provision for high-speed trunk road. Major steps in the design of noise mitigation measures for the compliance of noise standards stipulated in the EIAO-TM and the requirements of EIAO Guidance Note No. 12/2005 regarding traffic noise impact assessment are as follows:

(a) The predicted peak hour traffic flows at Year 2036 (highest traffic volume within 15 operational years starting from Year 2021) are considered to evaluate traffic noise levels at all noise assessment points.

(b) “Baseline” study, which takes into account all existing representative site layouts, building developments, roads and the noise mitigation measures within the Noise Assessment Area at Year 2036, is conducted. Noise mitigation measures for the Project roads are not included in this “baseline” study (unmitigated scenario).

(c) Necessary direct noise mitigation measures along the DP Roads are considered based on the results from the “baseline” study.

(d) The necessity for the application of direct noise mitigation measures (noise barriers/ enclosures) is determined based on the following conditions:-

i) If the predicted overall noise levels at the noise assessment points do not exceed the specified noise standards in the EIAO-TM (refer to Table 4‑3 above), no direct noise mitigation measures along the DP Roads are required;

ii) If the predicted overall noise levels at the noise assessment points exceed the specified noise standards stipulated in the EIAO-TM, direct noise mitigation measures shall be considered, such that either requirement (1) or (2)+(3) below could be fulfilled:

(1) The mitigated overall noise level is not higher than the specified noise level standards in the EIAO-TM; or

(2) The mitigated noise level arising from the DP Roads only is not higher than the specified noise level standards in the EIAO-TM; and

(3) The contribution of the mitigated noise level arising from the DP Roads to the mitigated overall noise level is less than 1.0 dB(A).

4.8.17 Total number of dwellings, classrooms and other noise sensitive elements that will be benefited from and be protected by provision of direct noise mitigation measures is also determined as follows:

(a) Dwellings, classrooms and other noise sensitive elements that will benefit from provision of direct noise mitigation measures are those:

i) exposed to overall traffic noise levels exceeding the specified noise level standards in the EIAO-TM under the unmitigated scenario;

ii) benefited at least 1.0 dB(A) from the implementation of the direct noise mitigation measures.

(b) Dwellings, classrooms and other noise sensitive elements that will be protected by provision of direct noise mitigation measures are those:

i) exposed to overall traffic noise levels exceeding the specified noise level standards in the EIAO-TM under the unmitigated scenario;

ii) exposed to overall traffic noise levels complying with the specified noise level standards in the EIAO-TM with the implementation of the direct noise mitigation measures.

4.8.18 As presented in Section 4.7 with regards to the road traffic noise prediction results under the unmitigated scenario, direct noise mitigation measures were required and designed on the east side along Bridge H as well as LNRS such that noise from the DP Roads is not higher than the relevant standards and has no significant contribution to the overall noise from other existing roads. According to the “Guidelines on Design of Noise Barriers” published by Highways Department and Environmental Protection Department, absorptive panels will be provided to the lower portion (i.e. 2 to 3 meters) of the proposed noise screening structures in order to reduce the reflection of noise. Details of the proposed direct noise mitigation measures are described in Table 4‑11 and their location and cross-sections are shown in Figures 4.4A to 4.4C.

Table 4‑11 Summary of Proposed Noise Mitigation Measures

Proposed Noise Mitigation Measure			Road Name	Direction	Target NSRs
ID	Description	Length (m)
A	5.5m high with 2.5m cantilevered barrier at 45°	85	Bridge H	Southbound	Lai King Catholic Secondary School, Ha Kwai Chung Polyclinic and Special Services Centre, and Fung King House
B	5.5m vertical barrier	20	Bridge H	Southbound	Lai King Catholic Secondary School, Ha Kwai Chung Polyclinic and Special Services Centre, and Fung King House
C	5.5m high with 2.5m cantilevered barrier at 45°	230	Bridge H	Southbound	Lai King Catholic Secondary School, Ha Kwai Chung Polyclinic and Special Services Centre, and Fung King House
D	5.5m high with 3.5m cantilevered barrier at 45°	45	Bridge H	Southbound	Fung King House, HKEAA-Lai King Assessment Centre
-	Low noise road surfacing ^[1]	-	Bridge H	-	Lai King Catholic Secondary School, Ha Kwai Chung Polyclinic and Special Services Centre, and Fung King House, HKEAA-Lai King Assessment Centre

Notes:

_[1] LNRS is applied on highways with speed 70kph or above in general. Such mitigation measure has been included in both unmitigated scenario and mitigated scenario in road traffic noise impact analysis. The above table only describes the mitigation measures on designated project roads (Bridge H) that is under this noise impact assessment. Although Bridge G would not constitute any material change and is classified as non-DP road, it is also a high-speed trunk road, LNRS will be re-provisioned after minor widening works and be applied in noise model as well.

4.8.19 Table 4-12 summarized the predicted road traffic noise level at each identified NSR with the proposed direct noise mitigation measures described in Table 4‑11. Detailed results at each floor of each noise assessment point are presented in Appendix 4-10.

4.8.20 In Table 4-12, it shows that with the application of the proposed direct noise mitigation measures along the DP Roads, the predicted overall road traffic noise levels at all of the identified NSRs will comply with the noise standards stipulated in the EIAO-TM, or that the predicted road traffic noise level from the DP Roads only will not exceed the noise standards stipulated in the EIAO-TM and the contribution of traffic noise arising from the DP Roads to the overall noise level will be less than 1.0 dB(A). In this regard, the application of indirect technical remedies is considered to be not necessary.

Table 4‑12 Predicted Road Traffic Noise Levels at Each Identified NSR under the Mitigated Scenario

NSR	Description	Noise Standard Under TM-EIAO, dB(A)	Range of Predicted Noise Level (Mitigated) (L10(1hour), dB(A))			Further Mitigation Measures Required? ^[1]
			Overall Noise Level	Predicted Noise Levels due to Other Roads	Predicted Noise Levels due to DP Roads only
NSR1	New Kwai Fong Gardens Block A	70	70~77	70~77	32~52	No
NSR2	Lingnam Dr. Chung Wing Kong Memorial Secondary School	65	72~77	72~77	35~56	No
NSR3	Lai King Catholic Secondary School	65	70~81	70~81	44~59	No
NSR4	Ha Kwai Chung Polyclinic and Special Services Centre	55	69~80	69~80	44~54	No
NSR5	Fung King House	70	70~84	70~84	46~60	No
NSR6	Wo King House	70	57~76	57~76	33~42	No
NSR7	Ming King House	70	57~80	57~80	34~63	No
NSR8	Yat King House	70	55~76	55~76	35~52	No
NSR9	HKEAA-Lai King Assessment Centre	65	77~81	77~81	56~65	No
NSR10	Yin Lai Court - Yin Kwong House (Block A)	70	69~78	69~78	37~59	No
NSR11	Yin Lai Court - Yin Tak House (Block B)	70	69~78	69~78	38~58	No
NSR12	Yuet Lai Court - Lai Hung House	70	70~74	70~74	26~35	No
NSR13	Yuet Lai Court - Lai Ha House	70	67~75	67~75	32~49	No
NSR14	Yuet Lai Court - Lai Wah House	70	64~75	64~75	34~48	No
NSR15	Yuet Lai Court - Lai Wan House	70	66~74	66~74	34~47	No
NSR16	Yeung King House (Block 5)	70	74~78	74~78	37~50	No
NSR17	On King House (Block 6)	70	66~78	66~78	26~46	No
NSR18	Clothing Industry Training Centre	65	69~71	69~71	35~39	No

Notes:

^[1] Further direct mitigation measures are required if (a) noise level from Project roads only > noise standards under EIAO-TM; or (b) overall noise level> noise standards under EIAO-TM, and difference between overall noise levels and noise levels of Other Roads ≥ 1.0 dB(A).

4.8.21 Total number of dwellings, classrooms and other noise sensitive elements that will be benefited from and be protected by provision of the direct noise mitigation measures are summarized in Table 4.13. As mentioned previously, noise contribution from the proposed DP Roads are relatively low as compared with the other existing roads. There is why the noise alleviation effectiveness contributed by the proposed mitigation measures appears to be relatively insignificant as reflected by the number of estimated benefit and protection. Only 85 of the represented dwellings, classrooms and other noise sensitive elements will benefit from, and 18 of them will be protected by provision of the proposed noise mitigation measures.

Table 4-13 Total Number of Dwellings, Classrooms and Other Noise Sensitive Elements that will be Benefitted from and be Protected by Provision of the Direct Noise Mitigation Measures

NSR	Description	No. of Dwellings Represented	No. of Dwellings Exceeding EIAO Noise Criteria ^[1]	No. of Dwellings benefitted from noise mitigation measures ^[2]	No. of Dwellings Protected from Noise Mitigation Measures ^[3]
Residential Dwellings
NSR1	New Kwai Fong Gardens Block A	128	126	0	0
NSR5	Fung King House	420	417	83	3
NSR6	Wo King House	280	133	0	0
NSR7	Ming King House	360	225	2	5
NSR8	Yat King House	506	288	0	10
NSR10	Yin Lai Court - Yin Kwong House (Block A)	105	94	0	0
NSR11	Yin Lai Court - Yin Tak House (Block B)	105	101	0	0
NSR12	Yuet Lai Court - Lai Hung House	88	86	0	0
NSR13	Yuet Lai Court - Lai Ha House	88	84	0	0
NSR14	Yuet Lai Court - Lai Wah House	88	82	0	0
NSR15	Yuet Lai Court - Lai Wan House	88	84	0	0
NSR16	Yeung King House (Block 5)	210	210	0	0
NSR17	On King House (Block 6)	182	56	0	0
	Sub-total	2648	1986	85	18
Classrooms
NSR2	Lingnam Dr. Chung Wing Kong Memorial Secondary School	48	48	0	0
NSR3	Lai King Catholic Secondary School	48	48	0	0
NSR9	HKEAA-Lai King Assessment Centre	36	36	0	0
NSR18	Clothing Industry Training Centre	48	48	0	0
	Sub-total	180	180	0	0
Other Noise Sensitive Elements
NSR4	Ha Kwai Chung Polyclinic and Special Services Centre	48	48	0	0
	Sub-total	48	48	0	0
	Total	2876	2214	85	18

Notes:

^[1] Number of dwellings, classrooms and other noise sensitive exposed to overall road traffic noise levels exceeding the noise standards stipulated in the EIAO-TM (refer to Table 4‑3).

^[2] Dwellings, classrooms and other noise sensitive elements benefitted from noise mitigation measures are those exposed to overall road traffic noise exceeding noise standards stipulated in the EIAO-TM under unmitigated scenario and are benefited at least 1.0 dB(A) from the implementation of the noise mitigation measures.

^[3] Dwellings, classrooms and other noise sensitive elements protected by noise mitigation measures are those exposed to overall road traffic noise exceeding noise standards stipulated in the EIAO-TM under unmitigated scenario and exposed to overall road traffic noise compiling with the noise standards stipulated in the EIAO-TM with the implementation of the noise mitigation measures.

4.9 Evaluation of Residual Impacts

Construction Phase

4.9.1 In view of the results listed in Table 4-10 provided in Appendix 4-9, it can be noted that the predicted construction noise levels with noise mitigation measures at all NSRs would comply with the corresponding construction noise limits except NSR3 and NSR9 with exceedance during examination period.

4.9.2 The predicted residual impacts are associated with assessment criteria during examination periods, as summarized in Table 4‑14.

Table 4‑14 Predicted Residual Construction Noise Period during Examination Period

NSR		Predicted Residual Construction Noise Impact
ID	Description	Period ^[2]	Exceedance
NSR3	Lai King Catholic Secondary School ^[1]	March 2018 to July 2018; December 2018 to January 2019; March to July 2019; April to July 2020; December 2020; May 2021 and July 2021 (Total 20 months)	3-5 dB(A) 1-3 dB(A) 1-2 dB(A) 1-3 dB(A) 1 dB(A) 1-2 dB(A)
NSR9	HKEAA-Lai King Assessment Centre^[1]	January 2020; April 2020 (Total 2 months)	1-2 dB(A) 1 dB(A)

Notes:

^[1] Air-conditioning systems were noted on site at these NSRs

^[2] Examination period assumed to be December, January, March-July of each year

4.9.3 As shown in Table 4-14 above, the predicted residual impact are limited to school examination periods, where the daytime construction noise criterion is 5dB lower than the normal daytime school criterion. Scheduling of construction works outside school examination period to less intrusive periods would definitely reduce the overall noise impacts at the NSRs and for ensuring compliance with the construction noise criterion at some of the NSRs. The Contractor shall liaise with the school representative(s) to obtain the examination schedule and avoid noisy construction activities during school examination period. Environmental and Audit requirements during construction of the Project would be discussed in Section 4.10 below and separate Environmental Monitoring and Audit (EM&A) Manual.

Operation Phase

4.9.4 As shown in Appendix 4.10, the predicted noise levels at most assessment points would exceed the relevant traffic noise standard. However, the traffic noise contribution from the concerned DP Roads is less than 1.0 dB(A) such that the traffic noise impact arising from the Project is considered insignificant. The noise exceedance is due to existing traffic on non-Project roads. Moreover, the traffic noise emanating from the concerned DP Roads would also comply with the relevant standard after mitigation that no further indirect mitigation measures is required.

4.10 Environmental Monitoring and Audit

4.10.1 Environmental monitoring and audit measures are recommended during the construction and first year of Project operation. Schedule and extent of the monitoring program is presented in the stand-alone Environmental Monitoring and Audit (EM&A) Manual. A proactive EM&A program is necessary to be provided by the contractor, in order to ensure that construction noise impact to the NSRs should be minimized as far as practicable. An appropriate path for noise complaints handling procedures is a key element of the EM&A program. Detailed implementation schedules of all mitigation measures are also provided in the EM&A Manual.

4.11 Conclusion

4.11.1 During construction phase, practical mitigation measures such as the use of QPME, temporary noise barriers, noise jackets, mufflers and limiting the number of plants operated concurrently, are proposed to minimise construction noise impact.

4.11.2 Further mitigation measures including good site practices as well as proper scheduling to avoid noisy construction during school examinations, can be adopted to further minimize the construction noise impact.

4.11.3 In the operational noise impact assessment, potential traffic noise impacts to the identified NSRs within the 300m study area have been evaluated based on the maximum traffic flow projection of 15 years after the completion of the Project (i.e. year 2036). It was predicted that the traffic noise levels arising from the Project at some NSRs exceed the EIAO criteria. As a result, direct noise mitigation measures such as cantilevered noise barriers, vertical noise barrier and LNRS have been proposed on the DP Roads for the compliance of noise criteria under the EIAO-TM. With the incorporation of the proposed direct noise mitigation measure, it is anticipated that the noise levels from the DP Roads at all of the identified NSRs will comply with the criteria.

4.11.4 Environmental monitoring and auditing should be implemented to ensure the application of necessary noise mitigation measures, noise monitoring, as well as to establish an appropriate path for noise complaints handling. EM&A Manual will be prepared separately from this report.