4 NOISE.. 4-1

4.1 Introduction. 4-1

4.2 Environmental Legislation, Policies, Plans, Standards and Criteria. 4-1

4.3 Description of the Environment 4-3

4.4 Sensitive Receivers. 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. 4-9

4.9 Evaluation of Residual Impacts. 4-10

4.10 Environmental Monitoring and Audit 4-10

4.11 Conclusion. 4-10

4 NOISE

4.1 Introduction

4.1.1 This section presents the potential noise impacts arising from the construction of Wan Chai East Sewage Outfall. It is expected that construction noise impact will arise from the proposed Project as well as the nearby concurrent projects (i.e. other Schedule 2 Designated Projects). Cumulative daytime construction noise impacts are assessed in this study. At the time of carrying out this EIA, information on the two potential future railway projects (i.e. SCL and NIL) were not available, therefore the cumulative noise impact arising from these two railway projects has not been assessed in this section. Construction of Wan Chai East Sewage Outfall has been scheduled to be carried out during unrestricted hours, therefore an indicative construction noise assessment for restricted hours was not undertaken.

4.1.2 In view of the project nature, no adverse noise impact during the operation phase would be anticipated. Thus, this section would only focus on construction noise impact assessment.

4.2 Environmental Legislation, Policies, Plans, Standards and Criteria

General

4.2.1 Noise impacts have been assessed in accordance with the criteria and methodology given in the Technical Memoranda (TMs) under the Noise Control Ordinance (NCO), and Annexes 5 and 13 in the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).

4.2.2 The NCO and EIAO provide the statutory framework for noise control. Assessment procedures and standards are set out in five TMs listed below:

· EIAO-TM

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

· TM on Noise from Percussive Piling (PP-TM)

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

· TM on Noise from Places other than Domestic Premises, Public Places or Construction Sites (IND-TM)

Construction Noise – General Construction Works

4.2.3 The NCO provides the statutory framework for noise control of construction work, other than percussive piling, using powered mechanical equipment (PME) between the hours of 1900 and 0700 hours or at any time on Sundays and general holiday (that is, restricted hours). Noise control on construction activities taking place at other times is subject to the Criteria for Evaluating Noise Impact stated in Table 1B of Annex 5 in the EIAO-TM. The noise limit is L_{eq (30 minutes)} 75 dB(A) at the façades of dwellings and 70 dB(A) at the façade of schools (65 dB(A) during examinations).

4.2.4 Between 1900 and 0700 hours and all day on Sundays and public holidays, activities involving the use of PME for the purpose of carrying out construction work is prohibited unless a construction noise permit (CNP) has been obtained. A CNP may be granted provided that the Acceptable Noise Level (ANL) for the NSRs can be complied with. ANLs are assigned depending upon the area sensitive rating (ASR). The corresponding basic noise levels (BNLs) for evening and night time periods are given in Table 4.1.

Table 4.1 Construction Noise Criteria for Activity other than Percussive Piling

Time Period	Basic Noise Level (BNLs), Leq (30-min) dB(A)
	ASR A	ASR B	ASR C
Evening (1900 to 2300 hours) ^(1)	60	65	70
Night (2300 to 0700 hours)	45	50	55

Notes: (1) Includes Sundays and Public Holidays during daytime and evening

4.2.1 Despite any description or assessment made in this EIA Report on construction noise aspects, there is no guarantee that a Construction Noise Permit (CNP) will be issued for the project construction. The Noise Control Authority will consider a well-justified CNP application, once filed, for construction works within restricted hours as guided by the relevant Technical Memoranda issued under the Noise Control Ordinance. The Noise Control Authority will take into account contemporary conditions / situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP. Nothing in this EIA Report shall bind the Noise Control Authority in making his decision. If a CNP is to be issued, the Noise Control Authority 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.

4.2.2 Percussive piling is prohibited between 1900 and 0700 hours on any weekday not being a general holiday and at any time on Sunday or general holiday. A CNP is required for the carrying out of percussive piling between 0700 and 1900 hours on any day not being a general holiday. PP-TM sets out the requirements for working and determination of the permitted hours of operations. ANLs for percussive piling for different types of NSRs are shown in Table 4.2.

Table 4.2 Acceptable Noise Levels for Percussive Piling

NSR Window Type or Means of Ventilation	ANL, Leq (30-min) dB(A)
NSR (or part of NSR) with no windows or other opening	100
NSR with central air conditioning system	90
NSR with windows or other openings but without central air conditioning system	85

Note: 10 dB(A) shall be subtracted from the ANLs shown above for NSRs which are hospitals, medical clinics, educational institutes, courts of law or other NSRs which are considered by the Authority to be particularly sensitive to noise.

4.2.3 In accordance with PP-TM, the permitted hours of operation for carrying out of percussive piling work, subject to the issuance of a CNP, are listed in Table 4.3.

Table 4.3 Permitted Hours of Operation for Percussive Piling

Amount by which Corrected Noise Level (CNL) exceeds Acceptable Noise Level (ANL), CNL-ANL	Permitted hours of operation on any day not being a general holiday
-10 dB(A) < CNL-ANL	Nil
CNL-ANL £ -10 dB(A)	0700 to 1900

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

· erecting or dismantling of formwork or scaffolding

· loading, unloading or handling of rubble, wooden boards, steel bars, wood or scaffolding material

· hammering

4.2.5 In general, it should not be presumed that a CNP would be granted for carrying out PCW within a designated area during the restricted hours. The CNP may be granted for the execution of construction works during restricted hours involving the use of PME and / or SPME if the relevant Acceptable Noise Levels and criteria stipulated in the GW-TM and DA-TM can be met.

4.3 Description of the Environment

4.3.1 The existing land uses in Wan Chai near the proposed Project are commercial, residential and recreational uses. The dominant existing noise source comes from the road traffic on busy Gloucester Road.

4.3.2 Since the works programme of the Project will overlap with other Schedule 2 DPs in some periods, cumulative construction noise impacts would be expected at some noise sensitive receivers.

4.4 Sensitive Receivers

4.4.1 In order to evaluate the construction noise impacts from the Project, representative existing noise sensitive receivers (NSRs) within 300m from the boundary of the Project (Study Area) are identified for assessment. Only the first layer of NSRs has been identified for assessment because it would provide acoustic shielding to those receivers at further distance behind. According to the normal practices adopted for similar land uses in Hong Kong (e.g. Visitor Centre of Hong Kong Wetland Park), the commercial buildings and the planned Harbour Education Centre would be provided with central air-conditioning system and they do not rely on openable window for ventilation. Thus, no adverse noise impact upon these premises would be expected and, therefore they are not selected for noise impact assessment. Table 4.4 and Figure 4.7 show the representative NSRs selected for construction noise impact assessment. The photographs of the representative NSRs are shown in Appendix 4.4. These representative assessment points for quantitative noise assessment have been agreed with the Environmental Protection Department (see Appendix 15.1).

Table 4.4 Representative Existing Noise Sensitive Receivers

NSR	Section	Location	Use	Ground elevation (mPD)	No. of Floors
N2	Wanchai	Causeway Centre	Residential	4.0	42
N3	Wanchai	Gloucester Road 169-170	Residential	3.7	12

4.5 Assessment Methodology

Construction Noise

4.5.1 The Schedule 3 Designated Project is scheduled to be commenced in early 2009 and to be completed in 2016. According to the construction programme, there are eight major construction tasks (as shown in Appendix 2.5). Some individual tasks have different stages. Table 4.5 summarises the different tasks and phasing. All construction tasks are planned to be carried out during unrestricted hours. Figure 3.4 shows the locations of work sites.

Table 4.5 Summary of Construction Tasks and Stages

Item	Tasks and Stages	Construction Period	Main Construction Elements
1 Causeway Bay Reclamation
1.1	Temporary Relocation Causeway Bay Typhoon Shelter(CBTS)	January 2009 to February 2016	Temporary Breakwater Relocation Mooring to Temporary CBTS Relocation Mooring back to CBTS
1.2	CBTS Temporary Reclamation Stage 1	August 2009 to May 2012	Dredging, temp seawalls and filling (TCBR1) CWB Tunnel (TCBR1) CWB Tunnel (Cross Harbour Tunnel)(CHT)
1.3	CBTS Temporary Reclamation Stage 2	November 2009 to May 2012	Dredging, temp seawalls and filling (TCBR2) CWB Tunnel (TCBR2)
1.4	CBTS Temporary Reclamation Stage 3	January 2011 to April 2014	Dredging, temp seawalls and filling (TCBR3) CWB Tunnel (TCBR3)
1.5	CBTS Temporary Reclamation Stage 4	May 2012 to November 2015	Dredging, temp seawalls and filling (TCBR4) CWB Tunnel (TCBR4)
1.6	Temp Diversion of Cooling Water System	October 2010 to January 2016
1.7	Promenade along CBTS	November 2015 to March 2016
1.9	Slip Road & Victoria Park Reprovisioning	August 2013 to March 2015	Victoria Park Road Traffic Division Slip Road 8 &Tunnel Transplant Trees in Victoria Park At-grade Road, Landscaped deck Reinstate Landscape work in VP
2 Ex-PCWA Temporary Reclamation
2.1	Temporary Reclamation PCWA Stage 1	February 2009 to May 2012	Dredging, Filing and Seawall (PCWAE) CWB Tunnel (PCWAE)
2.2	Temporary Reclamation PCWA Stage 2	March 2012 to May 2015	Dredging, Filing and Seawall (PCWAW) CWB Tunnel (PCWAW)
3 Wan Chai Reclamation
3.1	Wan Chai Reclamation Stage 1	January 2009 to February 2011	Dredging, Seawalls and Filling Drainage Culverts Cooling Water Syetem CWB Tunnel(WCR1)
3.2	Wan Chai Reclamation Stage 2	January 2011 to May 2013	Dredging, Seawalls and Filling CWB Tunnel Promenade
3.3	Wan Chai Reclamation Stage 3	April 2011 to March 2015	Dredging, Seawalls and Filling CWB Tunnel Promenade
3.4	Wan Chai Reclamation Stage 4	October 2012 to March 2015	Dredging, Seawalls and Filling Drainage Culverts CWB Tunnel Promenade
3.6	Ferry Pier Reprovisioning	February 2009 to May 2011	Temporary Ferry Piers New Ferry Piers
3.7	Helipad Reprovisioning	January 2009 to June 2010	Reprovisioning at HKCEC
3.8	Sewage Outfall	October 2009 to April 2011	Marine Section – Submarine Pipelines Land Section – New Pipeline
3.9	WSD’s Salt Water Pumping Station	February 2009 to October 2010	Construct New Pumping Station
3.10	Roads	October 2014 to September 2015	Road P2
4 HKCEC Reclamation
4.1	HKCEC Reclamation Stage 1 (Water Channel)	January 2009 to April 2016	Dredging, Seawalls and Filling Cooling Water Systems CWB Tunnel
4.2	HKCEC Reclamation Stage 2	January 2009 to March 2014	Dredging, Seawalls and Filling Drainage Culverts CWB Tunnel
4.3	MTR Tunnel Crossing	October 2010 to February 2012	Piling for Tunnel Units and Deck Tunnel and Deck Construction
4.4	HKCEC Reclamation Stage 3	March 2011 to October 2013	Dredging, Seawalls and Filling Drainage Culverts CWB Tunnel
4.5	Roads	March 2014 to November 2015	Road P2
5 Cross Harbour Watermains
5.1	Submarine Pipeline	January 2009 to September 2010	Lay New Submarine Pipeline
5.2	Lands Sections	September 2009 to May 2010	Lay Land Piplines HKCEC
6.0 North Point Reclamation
6.1	North Point Reclamation Stage 1	January 2009 to October 2010	Dredging, Seawalls and Filling CWB Tunnel (NPR1)
6.2	North Point Reclamation Stage 2	April 2009 to November 2012	Dredging, Seawalls and Filling (NPR2E, NPR2W) CWB Tunnel (NPR2W)
6.3	Promenade	August 2016 to December 2016	Promenade (NP) Final
7.0 Construction of Island Eastern Corridor Link (IECL)
7.2	IEC Connection Work	October 2010 to May 2016	IEC East Bound (E/B) (HFS to Mainline) IEC E/B Traffic Diversion Reconstruction IEC West Bound(W/B) IEC W/B Traffic Diversion Mainline Connection to IEC
7.3	East Portal and IEC Connection	May 2015 to August 2016	Portal Construction Traffic Diversion IEC E/B
10	Tunnel Building and Installation	November 2011 to May 2016
10.1	East Ventilation Building	November 2012 to September 2013	Superstructure of the Building E&M Work
10.2	Administration Building	February 2015 to November 2015	Substructure of the Building Superstructure of the Building E&M Work
10.3	Central Ventilation Building	January 2014 to January 2015	Substructure of the Building Superstructure of the Building E&M Work

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

4.5.3 In accordance with the EIAO, the methodology outlined in the GW-TM has been used for the assessment of construction noise (excluding percussive piling). Sound Power Levels (SWLs) of the equipment were taken from Table 3 of this TM. Where no SWL was supplied in the GW-TM, reference was made to BS 5228, previous similar studies or from measurements taken at other sites in Hong Kong. Schedule of powered mechanical equipment (PME) for the different construction tasks during normal daytime working hours is presented in Appendix 4.5.

4.5.4 It was assumed that all PME items required for a particular construction activity would be located at the notional or probable source position of the segment where such activity is to be performed. The assessment is based on the cumulative SWL of PME likely to be used for each location, taking into account the construction period in the vicinity of the receiver location. To predict the noise level, PME was divided into groups required for each discrete construction task. The objective was to identify the worst case scenario representing those items of PME that would be in use concurrently at any given time. The sound pressure level of each construction task was calculated, depending on the number of plant and distance from receivers. The noise levels at NSRs were then predicted by adding up the SWLs of all concurrent construction tasks.

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

Level of Uncertainty

4.5.6 The predictions of construction noise impact were based on the methodologies described in the GW-TM under the NCO. The methodology which had previously been applied in other EIA studies is generally accepted for use in assessing construction noise impacts against EIAO-TM noise criteria.

4.5.7 There would be some limitations such as the accuracy of the predictive base data for future conditions e.g. plant inventory for the proposed construction works. Uncertainties in the assessment of impacts have been considered when drawing conclusions from the assessment.

4.5.8 In carrying out the assessment, realistic worst case assumptions have been made in order to provide a conservative assessment of noise impacts. The construction noise impact was assessed based on conservative estimates for the types of plant and methods of working.

4.6 Identification of Environmental Impacts

Construction Noise

4.6.1 Schedule 2 Designated Project 5 is scheduled to be commenced in October 2009 and to be completed in March 2011. The construction tasks under DP5 include:

· Construction of Wan Chai Sewage Outfall

4.6.2 The construction tasks of DP5 and other projects taking place concurrently within 300m of a given NSR are considered to contribute to the cumulative impact at that NSR. Noise sources from the areas greater than this distance have been excluded from the assessment. The concurrent projects considered in the cumulative construction noise assessment for DP5 are as follows:

· DP1 - Central-Wanchai Bypass (CWB) including its road tunnel and slip roads

· DP3 - reclamation works including associated dredging works

4.7 Prediction and Evaluation of Environmental Impacts

Construction Noise

4.7.1 For normal daytime working hours, exceedences of the construction noise criteria (L_{eq (30 minutes)} 75 dB(A) for residential uses are predicted at representative NSRs in the absence of mitigation measures. Details of construction noise calculations and results are presented in Appendix 4.7. Results show that the predicted noise levels related to the concurrent construction works of the Project and other Schedule 2 DPs are in the range of 69 to 81 dB(A). A summary of the unmitigated construction noise levels of the representative NSRs during normal daytime working hours within the construction period of the Project is listed in Table 4.6. Noise mitigation measures would therefore be required to reduce noise levels to the stipulated standard.

Table 4.6 Summary of Unmitigated Construction Noise Levels at Representative NSRs During Normal Daytime Working Hours

Representative NSRs	Predicted Unmitigated Construction Noise Levels during Normal Daytime Working Hour (Leq (30-min) dB(A))
N2	69 – 81
N3	72 – 79

4.8 Mitigation of Adverse Environmental Impacts

Construction Noise

4.8.1 In order to reduce the excessive noise impacts at the affected NSRs during normal daytime working hours, mitigation measures such as adopting quiet powered mechanical equipment and movable noise barrier are recommended. The above mitigation measures have been vetted and confirmed by the CEDD and HyD as being practicable in completing the works within scheduled timeframe. The Contractor may be able to obtain particular models of plant that are quieter than the PMEs given in GW-TM. It is considered too restrictive to specify that a Contractor has to use specific items of plant for the construction operations. It is practical to specify the total SWL of all plant to be used on site so that the Contractor is allowed some flexibility to select plant to suit his needs.

4.8.2 In this assessment, the recommended quiet PME are taken from the BS 5228: Part 1: 1997 and the website of EPD, and the PME are known to be available in Hong Kong.

4.8.3 The lists of quiet PME adopted in the installation works of pipelines (marine and land section) during normal daytime working hours are shown in Appendix 4.13.

4.8.4 To alleviate the construction noise impact on the affected NSRs, movable noise barriers are proposed to be provided for particular items of plant for installation of pipelines (land section). It is anticipated that a movable noise barrier with a cantilevered upper portion located within 5m from any static or mobile plant can provide 5 to 10 dB(A) noise reduction.

4.8.5 The mitigation measures for the items of PME in each construction task have been shown in Appendix 4.13.

4.8.6 As shown in Appendix 4.14, with the use of quiet equipment for the Project as well as noise mitigation measures for other Schedule 2 DPs, the overall noise levels at NSRs would be reduced by 10 to 12 dB(A), depending on the type of construction activities. The predicted cumulative construction noise levels at the representative NSRs would comply with the EIAO-TM construction noise criteria.

4.8.7 A summary for mitigated noise levels during normal daytime working hours at representative NSRs is presented in Table 4.7.

Table 4.7 Summary of Mitigated Construction Noise Levels at Representative NSRs during Normal Daytime Working Hours

Representative NSRs	Predicted Mitigated Construction Noise Levels during Normal Daytime Working Hour (Leq (30-min) dB(A))
N2	64 - 71
N3	62 - 67

4.9 Evaluation of Residual Impacts

Construction Noise

4.9.1 With the implementation of the above-mentioned mitigation measures, the construction noise levels at all representative NSRs are predicted to comply with the noise standards stipulated in the EIAO-TM. No residual impacts at the representative NSRs are anticipated.

4.9.2 In addition to the above-mentioned mitigation measures, the good site practices listed below shall be adopted by all the Contractors to further ameliorate the noise impacts. Although the noise mitigating effects are not easily quantifiable and the benefits may vary with the site conditions and operating conditions, good site practices are easy to implement and do not impact upon the works schedule.

Ÿ Only well-maintained plant shall be operated on-site and plant shall be serviced regularly during the construction program.

Ÿ Silencers or mufflers on construction equipment shall be utilised and shall be properly maintained during the construction program.

Ÿ Mobile plant, if any, shall be sited as far away from NSRs as possible.

Ÿ Machines and plant (such as trucks) that may be in intermittent use shall be shut down between works periods or shall be throttled down to a minimum.

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

Ÿ Material stockpiles and other structures shall be effectively utilised, wherever practicable, in screening noise from on-site construction activities.

4.10 Environmental Monitoring and Audit

Construction Noise

4.10.1 An EM&A programme is recommended to be established according to the predicted occurrence of noisy activities. All the recommended mitigation measures for daytime normal working activities should be incorporated into the EM&A programme for implementation during construction. Details of the programme are provided in the stand-alone EM&A Manual.

4.11 Conclusion

Construction Phase

4.11.1 This assessment has predicted the construction noise impacts of the Project during normal daytime working hours, taking into account other concurrent projects including other Schedule 2 DPs. The predicted unmitigated noise levels would be in the range of 69 to 81 dB(A) at the representative NSR. With the use of quiet PME and movable noise barriers for the Project and implementation of the noise mitigation measures for other Schedule 2 DPs, the predicted cumulative noise levels at the representative NSRs would comply with the construction noise standard.

4.11.2 A construction noise EM&A programme is recommended to check the compliance of the noise criteria during normal daytime working hours.