10. Noise Impact Assessment

10.1 Introduction

This section has evaluated and assessed the noise impact quantitatively using standard acoustic principles and has focussed on the construction phase only. The assessment has been based on the criteria and guidelines for evaluation and assessing noise impact as stated in Annexes 5 and 13 of the EIAO-TM and covered the scope outlined in Section 3.4.8 of the EIA Study Brief.

10.2 Relevant Legislation, Standards & Guidelines

10.2.1 General Construction Activities during Non-Restricted Hours

Noise impacts arising from general construction activities other than percussive piling during the daytime period (07:00-19:00 hours of any day not being a Sunday or general holiday) shall be assessed against the noise standards tabulated in Table 10.1 below.

Table 10.1: Noise Standards for Daytime Construction Activities

Noise Sensitive Uses	0700 to 1900 hours on any day not being a Sunday or general holiday, L_{eq (30 min)}, dB(A)
All domestic premises including temporary housing accommodation	75
Hotels and hostel	75
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

10.2.2 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) 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.

Regardless of the results of the construction noise impact assessment for restricted hours, when assessing a CNP application for the use of Powered Mechanical Equipment (PME) during restricted hours, the Noise Control Authority will compare the BNLs, as promulgated in GW-TM, and the CNLs (after accounting for factors such as barriers effects and reflections) associated with the proposed PME operations. The BNLs are related to the noise sensitivity of the area in question and different Area Sensitivity Ratings have been established to reflect the background characteristics of different areas. The relevant BNLs are shown in Table 10.2 below.

Table 10.2: Basic Noise Levels (BNL, L_eq dB(A))

Time Period	Area Sensitivity Rating
Time Period	A	B	C
All days during the evening (1900 – 2300 hours) and general holidays (including Sundays) during the day and evening (0700 – 2300) hours	60	65	70
All days during the night-time (2300 – 0700 hours)	45	50	55

In addition to the general controls on the use of PME during the restricted hours, the Noise Control Authority has implemented more stringent control mechanisms via the DA-TM. The DA-TM regulates the use of five types of Specified Powered Mechanical Equipment (SPME) and three types of Prescribed Construction Work (PCW), which are non-PME activities, in primarily densely populated neighbourhoods called Designated Areas (DAs). The SPME and PCW are:

SPME:

¡ Hand-held breaker

¡ Bulldozer

¡ Concrete lorry mixer

¡ Dump truck

¡ Hand-held vibratory poker

PCW:

¡ Erection or dismantling of formwork or scaffolding

¡ Loading, unloading or handling or rubble, wooden boards, steel bars, wood or scaffolding material

¡ Hammering

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 can be referred to Technical Memorandum on Noise from Construction Work in Designated Areas (DA-TM) under NCO.

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 (with effective from 1 January 2009), both the landing locations of this project will fall within these areas.

As such, the application for CNP for any general construction activities involving the use of any PME shall refer to the GW-TM only. However, the Contractor has the responsibility to check the latest status and coverage of the Designated Areas at time of construction of the project.

Regardless of any description or assessment made in this chapter, 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.

10.3 Study Area

Clause 3.4.8.2 (i) of the EIA Study Brief prescribed the Study Area to be those within 300m from the Project or other project alignments as identified in the EIA. Figure 10.1 shows this study area (the 300m envelope) in details and the noise sensitive receivers (NSRs) within the area.

The representative NSRs are the first tier of most affected noise sensitive uses selected for the noise assessment to facilitate works planning and the implementation of necessary mitigation measures. Other NSRs further away from these first tier NSRs are expected to be less affected by comparison.

10.4 Noise Sensitive Uses

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.

There are numerous residential usage and schools situated along the proposed alignment which are identified as NSRs. For purpose of this construction noise assessment, representative NSRs close to the site have been selected within the Study Area for prediction of the levels of noise impact. Selected representative existing NSRs are tabulated in Table 10.3 below and shown in Figure 10.2 and Figure 10.3. Photos of representative existing NSRs are shown in Figure 10.4.

Based on site observation, Harbour Plaza Hotel in North Point is air-conditioned which do not rely on openable window for ventilation. Hence, the Harbour Plaza Hotel is not identified as NSRs.

There is a G/IC unit (planned schools) zoned in the vicinity of the proposed To Kwa Wan pigging station, however, based on the latest information obtained from Education Bureau (Appendix I1), the tentative school commencement year would be in 2014 academic year, which is beyond the construction programme of the proposed project, hence this G/IC unit is not identified as NSR.

Figure 10.5 shows the plan for the pipe laying operation of the proposed submarine gas pipelines as mentioned in Section 2.7.13. The distance between the construction activities and the noise sensitive receivers are then measured. Summary table of selected NSRs is shown in Table 10.3 below.

Table 10.3: Locations of the Existing Representative NSRs for CNIA

NSR ID	Description	Usage	Slant Distance to the laybarge (m)	Slant Distance to the Seawall (m)	Slant Distance to the Pigging Station (m) *
To Kwa Wan
SCH01	Po Leung Kuk Ngan Po Ling College	Institutional	370	176	122
SCH02	CCC Kei To Secondary School	Institutional	346	144	121
WFM	Wing Fai Mansion	Residential	449	241	194
SUV	Sunrise Villa	Residential	427	245	230
North Point
MHE	Model Housing Estate	Residential	334	159	144
KCM	Kut Cheong Mansion	Residential	325	124	190
LKB	Lai King Building	Commercial/ Residential	400	246	197
FSQ	North Point Fire Services Married Quarters	Residential	209	122	168

Note: (*) denotes notional distance between the NSRs and the Pigging Station

10.5 Assessment Approach & 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 approach used is as follows: -

1. Assume a project-specific equipment inventory for each work stage in Table 10.4 and Table 10.5 together with the number and type of PME that are considered likely for completing the works during the non-restricted hours;

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

3. For each of the representative NSRs in Table 10.3, with the use of the slant distance to the noise source as calculation distance, calculate the maximum unmitigated Predicted Noise Level (PNL) amongst all construction work sites, corrected for facade reflection to obtain the Corrected Noise Level (CNL);

4. If necessary, replace some of the PME with silenced equipment and/ or consider to use temporary noise barriers to calculate the mitigated noise impact;

5. Consider any potential impact from the concurrent projects; and

6. Compare the mitigated CNL with the noise standards given in Table 10.1 to determine acceptability and the need for further mitigation/ EM&A.

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)

10.6 Analysis of Construction Activities and Sources of Noise Impact

It is expected that works for the laying of submarine and land gas main can roughly be divided into several work stages. For the submarine laying works would start from trench dredging, and then laying of submarine gas pipelines and followed by backfilling.

The dredging works for the laying of submarine gas main may have potential to be conducted during the restricted hours (evening time, 1900 – 2300 and night-time, 2300 – 0700). A CNP would be applied for before carrying the works during the restricted hours.

To facilitate an estimate of the likely level of construction noise during the non-restricted hours, an inventory of project-specific PME needed has been assumed with the typical construction works are shown in Table 10.4 to Table 10.5 below. As confirmed by the project proponent, the plant inventory adopted in this assessment is technically feasible for undertaking the construction works.

Table 10.4: Tentative Construction Activities and Construction Plant List for Submarine Works

Construction Activities/ PME		TM Ref.	SWL dB(A)/ Unit	Quantity	Percentage on time
1	Trench Dredging
	Dredger (Grab dredger/ trailer hopper dredger)	CNP 063	112	1	100%
	Guard Boat (*)	N/A	110	3	100%
	Tug Boat	CNP 221	110	1	100%
Total SWL, dB(A)					117
2	Pipe Laying
2a	At Sea:
	Launching Barge (*)	N/A	104	1	100%
	Derrick Barge	CNP 061	104	5	100%
	Guard Boat (*)	N/A	110	3	100%
	Tug Boat	CNP 221	110	1	100%
	Crane, mobile/ barge mounted	CNP 048	112	5	100%
Total SWL, dB(A)					121
2b	On Land:
	Winch (pneumatic)	CNP 261	110	1	100%
	Generator, standard	CNP 101	108	2	100%
	Crane, mobile/ barge mounted	CNP 048	112	1	100%
	Air Compressor, air flow > 10m³/min and <= 30m³/min	CNP 002	102	2	100%
Total SWL, dB(A)					116
3	Backfilling
	Derrick Barge	CNP 061	104	1	100%
	Guard Boat (*)	N/A	110	3	100%
	Tug Boat	CNP 221	110	1	100%
Total SWL, dB(A)					116

Note:

[*] The SWL of Guard Boat is assumed same as the Tug Boat, and the SWL of Launching Barge is assumed same as the Derrick Barge

Table 10.5: Tentative Construction Activities and Construction Plant List for Landfall and Pigging Station Works

Construction Activities/ PME		TM Ref.	SWL dB(A)/ Unit	Quantity	Percentage on time
1	Mobilization/ Site Preparation
	Breaker, excavator mounted (pneumatic)	CNP 027	122	1	50%
	Excavator/ loader, wheeled/tracked	CNP 081	112	1	50%
	Lorry	CNP 141	112	1	50%
Total SWL, dB(A)					120
2	Landfall Site Construction
2a	*Seawall demolition ()**
	Breaker, excavator mounted (pneumatic)	CNP 027	122	2	50%
	Air Compressor, air flow > 10m³/min and <= 30m³/min	CNP 002	102	2	100%
	Crane, mobile/ barge mounted	CNP 048	112	1	100%
	Dump Truck	CNP 067	117	1	50%
	Generator, standard	CNP 101	108	1	100%
Total SWL, dB(A)					123
2b	*Seawall reinstatement ()**
	Crane, mobile/ barge mounted	CNP 048	112	1	100%
	Dump Truck	CNP 067	117	1	50%
	Excavator/ loader, wheeled/tracked	CNP 081	112	1	50%
	Lorry	CNP 141	112	1	50%
	Road Roller	CNP 185	108	1	100%
Total SWL, dB(A)					118
3	Construction of Pigging Station
3a	*Surface reinstatement ()**
	Group 1 – Site Excavation
	Excavator/ loader, wheeled/tracked	CNP 081	112	1	30%
	Group 2 – Filling
	Dump Truck	CNP 067	117	1	30%
	Group 3 – Surface Reinstatement
	Road Roller	CNP 185	108	1	30%
	Poker, vibratory, hand-held	CNP 170	113	1	30%
Total SWL, dB(A)					112
3b	*Facilities installation ()**
	Group 1 – Transportation of Material
	Lorry	CNP 141	112	1	25%
	Group 2 – Facilities Installation
	Generator, standard	CNP 101	108	1	100%
	Concrete Lorry Mixer	CNP 044	109	1	30%
	Poker, vibratory, hand-held	CNP 170	113	1	30%
	Excavator/ loader, wheeled/tracked	CNP 081	112	1	30%
Total SWL, dB(A)					117

Note:

[*] The construction activities of 2a/2b and 3a/3b would not carried out concurrently.

10.6.1 Unmitigated Construction Noise Impacts

Based on the staged construction activities and PME inventory, the predicted construction noise impacts of different construction stages for the unmitigated scenario have been summarised in Table 10.6 to Table 10.8 below together with a detailed calculation summary sheet shown in Appendix I2.

Table 10.6: Unmitigated Noise Impact due to the Laying of Submarine Gas Main

NSR ID	Usage	Slant Distance (m)	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Mitigation Measures Required?
To Kwa Wan
SCH01	Institutional	370	66	70	No
SCH02	Institutional	346	68	70	No
WFM	Residential	449	64	75	No
SUV	Residential	427	64	75	No
North Point
MHE	Residential	334	67	75	No
KCM	Residential	325	66	75	No
LKB	Commercial/ Residential	400	64	75	No
FSQ	Residential	209	70	75	No

Table 10.7: Unmitigated Noise Impact due to Landfall Site Construction

NSR ID	Usage	Slant Distance (m)	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Mitigation Measures Required?
To Kwa Wan
SCH01	Institutional	176	73	70	Yes
SCH02	Institutional	144	75	70	Yes
WFM	Residential	241	71	75	No
SUV	Residential	245	70	75	No
North Point
MHE	Residential	159	74	75	No
KCM	Residential	124	73	75	No
LKB	Commercial/ Residential	246	70	75	No
FSQ	Residential	122	77	75	Yes

Note: Bold figure denotes exceedance of relevant noise criteria

Table 10.8: Unmitigated Noise Impact due to the Construction of Pigging Station

NSR ID	Usage	Slant Distance (m)	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Mitigation Measures Required?
To Kwa Wan
SCH01	Institutional	122	66	70	No
SCH02	Institutional	121	66	70	No
WFM	Residential	194	62	75	No
SUV	Residential	230	61	75	No
North Point
MHE	Residential	144	65	75	No
KCM	Residential	190	62	75	No
LKB	Commercial/ Residential	197	62	75	No
FSQ	Residential	168	63	75	No

10.6.2 Cumulative Noise Impact from Concurrent Construction Activities

According to the construction programme, there are several individual construction tasks would be carried out concurrently, the cumulative construction noise impact has been assessed and summarised in Table 10.9 below and in Appendix I3.

Table 10.9: Cumulative Construction Noise Impact (Unmitigated)

NSR ID	Usage	Unmitigated Noise Level, dB(A)	Noise Criteria, dB(A)	Mitigation Measures Required?
To Kwa Wan
SCH01	Institutional	74	70	Yes
SCH02	Institutional	76	70	Yes
WFM	Residential	71	75	No
SUV	Residential	71	75	No
North Point
MHE	Residential	75	75	No
KCM	Residential	74	75	No
LKB	Commercial/ Residential	72	75	No
FSQ	Residential	77	75	Yes

Note: Bold figure denotes exceedance of relevant noise criteria

As shown in the tables above, exceedances of noise criteria were predicted, mitigation measures should be implemented to ameliorate the impacts.

10.6.3 Construction Noise Impact from Test before Backfilling and Hydrostatic/ Commissioning Test

After the laying of submarine gas pipelines and the construction of pigging station, test before backfilling and hydrostatic/ commissioning test will be carried out. Noise impact from both tests has been assessed and evaluated below.

As there is no detailed information for the test before backfilling and hydrostatic/ commissioning test including the number of machine(s) used at the preparation of EIA study, the total maximum allowable total sound power level (SWL) of the machine(s) employed on site is specified to meet the relevant noise criteria. Back calculation of the total maximum allowable SWL of the machine(s) is adopted and the assessment result is showed in Table 10.10 below.

Table 10.10: Total Maximum Allowable Sound Power Level (SWL) for Test before Backfilling and Hydrostatic/ Commissioning Test during Construction Phase

Nearest NSR ID	Usage	Slant Distance (m)	Distance Correction, dB(A)	Facade Correction, dB(A)	Maximum Allowable SWL, dB(A)
To Kwa Wan
WFM	Residential	194	-54	+3	126 (during school summer vacation)
SCH02	Institutional	121	-50	+3	117 (during normal school period)
SCH02	Institutional	121	-50	+3	112 (during examination)
North Point
MHE	Residential	144	-51	+3	123

Based on the assessment result above, the total maximum allowable SWL of the test before backfilling and hydrostatic/ commissioning test is ranged from 112-126 dB(A) at different location and period, the Contractor shall strictly follow the specification listed above to meet the noise criteria and closely liaise with the schools nearby before carrying out the activities. Noise mitigation measures including the use of movable noise barriers and/ or noise enclosure to block the direct line of sight to the receivers, installation of mufflers and/ or silencers on the machine(s) should be implemented if necessary.

10.7 Possible Noise Mitigation Measures and Mitigated Impacts

10.7.1 Use of Quiet Plant and Movable Noise Barrier

Quiet plant is defined as a PME which has a SWL lower than that given in the Technical Memorandum for Noise from Construction Work Other Than Percussive Piling for the same type of equipment. Examples of known SWLs of various types of quiet plant available in Hong Kong are as shown in Table 10.11 and have been successfully applied in other EIA/ works and contributed to achieve noticeable noise reduction.

Table 10.11: Recommended Quiet PME and the SWL

Quiet Plant	SWL, dB(A)	Reference
Mobile Crane	101	BS5228 C7-114
Breaker, excavator mounted (hydraulic), 52kW	106	BS5228 C8-12
Dump Truck, 309kW	103	BS5228 C3-39
Excavator (45kW) (Site excavation)	106	BS5228 C3-35
Wheeled excavator/ loader (52kW) (Facilities Installation)	102	BS5228 C6-28
Tracked loaded lorry, 310kW	105	BS5228 C3-59
Road Roller	101	BS5228 C8-30
Generator, super silenced	95	CNP 103
Poker, vibratory, hand-held	98	BS 5228 C6-40
Concrete lorry mixer (6m3)	100	BS5228 C6-23

As the use of movable noise barrier on the PMEs in the marine section is impractical, purpose-built movable cantilevered type noise barriers and site hoarding should be used to mitigate construction noise directly at sources and the plant inside the work sites of pigging station on the landmain works only. According to the EIAO Guidance Note No. 9/2004, a 5 dB(A) and 10 dB(A) reduction is assumed for movable plant and stationary plant respectively. The noise screening effect benefit for each item of plant considered in this assessment is listed as follows:

Pipe laying (on land) during laying of submarine gas pipelines

¡ Stationary plant – assume 10 dB(A) reduction: Winch, Generator and Air compressor

The movable noise barriers and site hoardings 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 barrier.

By replacing the regular PMEs with the quieter ones and the use of movable noise barrier, the maximum SWLs for the revised plant inventory is listed in Table 10.12 below.

Table 10.12: Maximum SWLs of Plant Inventory with Mitigation Measures Implemented

Construction Activities		Total SWL, dB(A)
Marine Works	Trench Dredging	117
	Pipe Laying (at sea)	118
	Pipe Laying (on land)	104
	Backfilling	116
Land Works	Mobilizations/ Site Preparation	111
	Seawall demolition	110
	Seawall reinstatement	109
	Construction of pigging station – Surface reinstatement	107
	Construction of pigging station – Facilities installation	103

The noise impact has been re-assessed and summarised in Table 10.13 to Table 10.14 with a detailed summary sheet was shown in Appendix I4 and the cumulative impact is shown in Appendix I5.

Table 10.13: Mitigated Noise Impact due to the Landfall Construction

NSR ID	Usage	Slant Distance (m)	Mitigated Noise Level, dB(A)	Noise Criteria, dB(A)
To Kwa Wan
SCH01	Institutional	176	60	70
SCH02	Institutional	144	62	70
North Point
FSQ	Residential	122	63	75

Table 10.14: Cumulative Construction Noise Impact (Mitigated)

NSR ID	Usage	Mitigated Noise Level, dB(A)	Noise Criteria, dB(A)
To Kwa Wan
SCH01	Institutional	64	70
SCH02	Institutional	65	70
North Point
FSQ	Residential	68	75

With all these measures in place, the mitigated construction noise impacts have been predicted with no exceedance of noise criteria. Moreover, the Contractor should closely liaise with the schools nearby (SCH01 and SCH02) to avoid the construction activities being carried out as far as possible during school hours, especially during the examination period.

By combining with the implementation of mitigation measures proposed and the designed EM&A requirements, construction noise impact should be controlled to within acceptable levels.

10.7.2 Construction Noise Impact from Pipe Laying on Landline

For the landmain laying works would start with excavation, and then the laying of landmain gas pipelines and followed by compaction. The laying of landmain gas pipeline will be carried out during the non-restricted hours only.

Given that the road is narrow and use for daily traffic, the frequency and the size of PME employed on site would be limited. The Contractor would like to prefer the use of smaller machines, for example, the use of mini-robot mounted excavators instead of the regular PME listed in the GW-TM in order not to block the road traffic use, and hence the construction noise impact would be minimised.

Nevertheless, due to the close proximity to the noise sensitive receivers, the Contractor is required to minimise the construction noise impact. It is recommended that the Contractor should also adopt good working practices in order to minimise construction noise as far as possible, e.g.:

¡ The Contractor shall adopt the Code of Practice on Good Management Practice to Prevent Violation of the Noise Control Ordinance (Chapter 400) (for Construction Industry) published by EPD;

¡ The Contractor shall observe and comply with the statutory and non-statutory requirements and guidelines;

¡ Before commencing any work, the Contractor shall submit to the Engineer Representative for approval the method of working, equipment and noise mitigation measures intended to be used at the site;

¡ The Contractor shall devise and execute working methods to minimise the noise impact on the surrounding sensitive uses, and provide experienced personnel with suitable training to ensure that those methods are implemented;

¡ Noisy equipment and noisy activities should be located as far away from the NSRs as practical;

¡ Unused equipment should be turned off. Number of operating PME should be kept to a minimum and the parallel use of noisy equipment / machinery should be avoided;

¡ Regular maintenance of all plant and equipment; and

¡ Material stockpiles and other structures should be effectively utilised as noise barriers, where practicable.

Construction noise impact assessment as a worst-case scenario that the PMEs are located at a point have been assessed and no residual impact is anticipated provided that proper implementation of proposed mitigation measures. However, in practice, the PMEs should be more spreaded out for each work stage along the marine section than being assumed in the calculations as point sources.

10.8 Potential Concurrent Projects

According to Section 2.11, there are potential concurrent projects identified which included the followings: -

¡ Dredging Works for Proposed Cruise Terminal at Kai Tak;

¡ Wan Chai Development Phase II and Central-Wan Chai Bypass (WCD II);

¡ Shatin Central Link (SCL);

¡ Trunk Road T2;

¡ Providing Sufficient Water Depth for Kwai Tsing Container Basin and its Approach Channel (KTCB); and

¡ Central Kowloon Route (CKR).

Although the Cruise Terminal project is located within the assessment area of this EIA project, the distance between the Cruise Terminal project and the noise sensitive receivers at North Point and To Kwa Wan would be over 500m, hence the cumulative impacts from the Cruise Terminal project is predicted minimal.

While the WCD II, Trunk Road T2 and KTCB are located outside the assessment area of this EIA project, no cumulative impact assessment is considered necessary.

Based on the best information available in the websites, the tentative construction programme of the Shatin Central Link would be commenced in 2010 and end in 2015, but detailed construction programme is not available now. Moreover, based on the latest information obtained from MTRC website, the nearest Ma Tau Wai Station is out of 300m assessment area, no cumulative noise impact is anticipated.

The CKR would be commenced in 2012 and end in 2016, but the CKR is all underground from Kai Tak Development to West Kowloon, hence, the potential airborne noise impact from this concurrent project would unlikely to contribute significant impact to NSRs.

10.9 Evaluation of Residual Impacts

No unacceptable residual noise impact due to construction of the submarine gas pipelines and associated facilities is expected.

10.10 Environmental Monitoring and Audit

Given the results from the impact predicted during the construction phase, to ensure that the nearby NSRs will not be subjected to unacceptable construction noise impact, an Environmental Monitoring and Audit (EM&A) programme is recommended. The details on monitoring and audit programme are discussed in the EM&A Manual.

10.11 Summary

This construction noise impact assessment has been based on a best estimate of the construction sequence and machines inventory.

The potential noise impact that could arise from daytime construction activities of the Project has been evaluated. With the use of quiet plant and the movable noise barriers, the construction noise impact can be mitigated to acceptable levels. The Contractor shall, from time to time, be aware of the noise impacts on the surrounding NSRs through adequate noise monitoring during the works so that adjustments could be made to control the construction noise levels. These requirements should be triggered by an Event and Action Plan as part of the EM&A which should be incorporated into the works contract in order to make it enforceable.