4                   Noise

4.1              Introduction

4.1.1        This Section provides an evaluation of the potential noise impacts associated with the construction and operational phases of the Northshore Lantau Development and CKWLR (the Project).  Supplementary information for the noise assessment is provided in Annex C.

4.1.2        During the construction phase of the Project, powered mechanical equipment (PME) employed in the construction of the proposed developments within the Draft RODP and the CKWLR will be the primary source of noise reaching the surrounding environment.  The major activities will include:

·                      site reclamation works and seawall construction;

 

·                      construction of the CKWLR alignment;

 

·                      construction of other transport infrastructure in the Project Area including Road P1, Road P2, the Access Road at Yam O, the Resort Roads, and other internal distribution roads;

 

·                      construction of government/institutions/community facilities including public transport interchanges, parking lots, police stations, and fire stations etc.;

 

·                      construction of residential and educational institutions at Siu Ho Wan;

 

·                      construction of the Northshore and Tsing Chau Tsai East developments;

 

·                      construction of the Penny’s Bay Rail Link (PBRL);

 

·                      construction of the Theme Park including its associated hotels and infrastructures at Penny's Bay;

 

·                      construction of a water recreational centre with a lake for irrigation and water sport recreational activities; and

 

·                      construction of utilities and support facilities.

 

4.1.3        During the operation of the Project, the principal sources of noise included are:

·                      road traffic comprising mainly those on the CKWLR, Road P1, Road P2, the existing NLH, and the planned Route 10-NLYLH;

 

·                      rail traffic from the proposed PBRL and the existing Airport Railway (including Airport Express Line and Tung Chung Line);

 

·                      Public Transport Interchanges (PTIs) at Yam O and Penny’s Bay;

 

·                      sewage pumping station at Penny’s Bay;

 

·                      Siu Ho Wan Water Treatment Works, Siu Ho Wan Sewage Treatment Works, and North Lantau Transfer Station;

 

·                      occasional operation of the existing CLP Gas Turbine Plant in Penny’s Bay (GTP);

 

·                      Theme Park Phase I and II operation including rides and fireworks displays;

 

·                      Theme Park Extension operation;

 

·                      water recreation centre;

 

·                      Tsing Chau Tsai East recreational development;

 

·                      helicopter and aircraft noise exposures over the proposed residential and institutional developments at Siu Ho Wan and the proposed village expansion area at Tso Wan; and  

 

·                      potential exposure of Theme Park (Phase I and II) resort hotels to noise from the future Container Terminal development south-east of the site.

 

4.1.4        Other developments proposed under the NLDFS will mainly be of commercial, or tourism uses.  As such, they will not be regarded as noise sources and are not included in our assessment.  These include:

·                      The developments at Northshore area (including the Theme Park Gateway, the Tourist and Convention Village and the Technodrome); and

 

·                      The Eco Park at Luk Keng Tsuen.

 

4.1.5        While a separate EIA study has been conducted for the Theme Park (Phase I and II) and its associated developments, key findings on noise impacts from the study are summarised in this Report for the evaluation of possible cumulative noise impacts.

4.1.6        Figure 4.1a shows the principal noise sources covered under the Project.

4.1.7        Where, according to the applicable noise guidelines or regulations, potential Project related  noise impacts are identified during either the construction or operational phases, appropriate mitigation measures are recommended and Environmental Monitoring and Audit (EM&A) requirements identified.

4.2              Statutory Requirements and Evaluation Criteria

Construction Noise

General

4.2.1        The principal legislation addressing the control of construction noise is the Noise Control Ordinance, Cap. 400 (NCO).  Various Technical Memoranda (TMs) stipulating control approaches and criteria have been issued under the NCO.  The following TMs are applicable to the control of noise from construction activities:

·                      Technical Memorandum on Noise from Percussive Piling (PP-TM);

·                      Technical Memorandum on Noise from Construction Work other than Percussive Piling (GW-TM); and

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

 

4.2.2        The EIAO and the EIAO-TM also provide guidelines for the assessment of noise impacts associated with construction activities.

4.2.3        Regardless of any noise impact description or assessment made in this EIA Report, the Noise Control Authority will be guided by the relevant TMs issued under the NCO in assessing any application, once filed, for a Construction Noise Permit (CNP) for works planned during restricted hours (i.e. 1900 to 0700 hours and any time on a general holiday including Sundays).  The Authority will consider all the factors affecting its decision taking the then prevailing situations and conditions into account.  Nothing in this EIA Report shall bind the Authority in making its decision and further, there is no guarantee that a CNP will be issued.  If a permit is to be issued, the Authority may include any conditions it considers appropriate and such conditions must be followed during the execution of the works covered by the permit.  Failing to do so may lead to cancellation of the permit and prosecution action under the NCO.

Percussive Piling

4.2.4        Under the PP-TM, percussive piling is prohibited at any time on Sundays and public holidays and during evening and night-time hours (1900-0700 hours) , Monday through Saturday.  A CNP is required in order to carry out such work during daytime hours (0700-1900 hours), Monday through Saturday.  As the issuance of a CNP by the Noise Control Authority would depend on the submission of an application by the Contractor, and therefore on the Contractor’s compliance with the percussive piling noise limits set out within the PP-TM, the assessment of this type of noise has not been included in this EIA.  However, for completeness, the process that would be followed in assessing a CNP application for percussive piling is described below.

4.2.5        In evaluating a CNP application for percussive piling, the Noise Control Authority would be guided by the PP-TM.  In assessing the potential noise impact, the EPD would consider the difference between the Acceptable Noise Levels (ANLs), as specified in the PP-TM, and the Corrected Noise Levels (CNLs) predicted to result from the proposed percussive piling activities.  Depending on the projected noise impacts at nearby Noise Sensitive Receivers (NSRs), the Noise Control Authority would determine the allowable time periods for percussive piling operations, as indicated in Table 4.2a. 

Table 4.2a - Permitted Hours of Operation for Percussive Piling (Note: the Use of Diesel, Pneumatic and/or Steam Hammers is prohibited)

 

General Construction Works During Restricted Hours

4.2.6        The NCO provides statutory controls on general construction works during restricted hours (i.e. 1900-0700 hours Monday to Saturday and at any time on Sundays and public holidays). The use of powered mechanical equipment (PME) for the carrying out of construction works during these restricted hours would require a CNP.  The Noise Control Authority will assess all CNP applications on a case by case basis and, in doing so, it will be guided by the GW-TM.

4.2.7        When assessing an application for the use of PME, the Noise Control Authority will compare the ANLs specified in the GW-TM with the CNLs (adjusted for any barrier and reflection effects) associated with the proposed PME operations.  The NCO requires that noise levels from construction at affected NSRs be less than a specified ANL.  The ANLs are related to the inherent noise sensitivity of the noise receiver areas in question, which in turn relate to the background noise characteristics of these areas.  Each noise receiver area is then assigned an Area Sensitivity Rating based on its predominant land use and the presence, if any, of Influencing Factors such as nearby industrial areas, major roads or airports.  The relevant ANLs for evenings and holidays and for night-time are provided in Table 4.2b.

Table 4.2b - Acceptable Noise Levels (ANLs, L_{Aeq, 5min} dB) for General Construction Works to be Carried out During Restricted Hours

Time Period	Area Sensitivity Rating
	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

 

4.2.8        In addition to the general controls on the use of PME during the restricted hours, the Noise Control Authority has implemented a more stringent scheme via the DA-TM.  In the interest of offering additional protection to the population, the carrying out of Prescribed Construction Work (PCW) is generally banned inside a Designated Area (DA).  As for the use of Specified Powered Mechanical Equipment (SPME) and/or carrying out PCW, as stated in DA-TM, it would be necessary to comply with DA-TM noise level requirements that are 15 dB(A) more stringent then those listed in the GW-TM before a CNP may be issued.  However, as construction works considered in the Project are not carried out in a DA, noise criteria as stipulated in the DA-TM would not be applicable for this EIA study.

4.2.9        Factors influencing the outcome of a CNP application, such as the assigning of ANLs, would be determined by the Noise Control Authority at the time of the application review based on the then prevailing site conditions.  It should be noted that conditions around the site(s) may change from time to time.

General Construction Works During Normal Working Hours

4.2.10    Although the NCO does not provide for the control of noise from construction activities during normal working hours (0700 to 1900 hours, Monday to Saturday), Annex 5 of the EIAO-TM specifies a limit of L_{eq, 30 min} 75 dB(A) for residential NSRs.  Annex 5 also provides construction noise limits for schools of L_{eq, 30 min} 70 dB(A) and 65 dB(A) during normal teaching periods and examination periods respectively.

4.2.11    Both the GW-TM and the EIAO-TM acknowledge the potential noise sensitivity of areas designated as Country Parks.  However, the GW-TM does not identify Country Parks themselves as NSRs.  Furthermore, while the EIAO-TM provides general construction noise limits at residences and schools during normal working hours, it provides no such limit for Country Parks. Therefore in this EIA, construction noise impact at Country Parks have generally been estimated in relative terms only.

Railway Noise

4.2.12    Railway noise is controlled under the NCO and the subsidiary Technical Memorandum for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites (IND-TM).  The IND-TM establishes ANLs for railway noise depending on the Area Sensitivity Ratings of the area where the NSR is located.  Again Area Sensitivity Ratings for all areas containing NSRs are based on the predominant land use and the presence of any influencing factors such as industrial areas, major roads and airports.

4.2.13    The relevant criteria are presented in Table 4.2c below and are to be met at a position 1 m from the window facade of the NSR.

Table 4.2c - NCO Railway Noise Assessment Criteria (ANLs, L_Aeq,30min dB)

 

4.2.14    The EIAO-TM provides additional criterion for assessing railway noise at identified NSRs.  This criterion, which appears in Table 4.2d, is expressed in terms of the A-weighted maximum noise level (L_Amax) due to individual railway noise events during the night-time (2300-0700 hours).

Table 4.2d - EIAO-TM Railway Noise Criterion

Parameter	Criterion Level in dB
Maximum A-weighted sound pressure level during 2300-0700 hours, LAmax	85

 

4.2.15    Country Parks are not specifically identified as NSRs in the IND-TM and are assigned no quantitative railway noise limit under the EIAO-TM.  Therefore, within this EIA, railway noise levels are predicted at the existing Lantau North Country Park and the Proposed Country Park Extension Area and are addressed qualitatively.

Fixed Plant Noise

Fixed Plant Inventory

4.2.16    Noise levels from fixed plant sources within the Study Area are required to comply with the EIAO-TM.  The fixed plant noise sources assessed in this EIA include:

·                      the PTIs at Yam O and Penny’s Bay;

·                      the sewage pumping station at Penny’s Bay;

·                      the Water and Sewage Treatment Works and the North Lantau Transfer Station near Siu Ho Wan;

·                      CLP’s G T P in Penny’s Bay;

·                      the Tsing Chau Tsai East recreational development; and

·                      the future Container Terminal development (previous Container Terminals 12 and 13) planned to the south-east of the Theme Park. 

4.2.17    While fixed plant noise from the Theme Park amusement operations (Phases I and II) has been assessed in detail in the Theme Park EIA[1], as well as the operation of the Theme Park (Phase III) Extension in this EIA, the key findings on noise issues are summarised in this Report.

4.2.18    The proposed residential and institutional developments at Siu Ho Wan has been assumed to be built after the completion of the redevelopment at the existing MTRC Siu Ho Wan Depot.  The depot site has been zoned Comprehensive Development Area (CDA) under the Siu Ho Wan Layout Plan.  The CDA development will include decking over of the depot and developed as a commercial podium with residential development above, hence fixed plant noise impact from the depot on the surrounding environment would be eliminated.

Fixed Plant Noise Criteria

4.2.19    The EIAO-TM requires that all fixed noise sources be located and/or designed such that:

·                      the total fixed source noise level at the facade of the nearest NSR is at least 5 dB(A) lower than the appropriate ANL as specified in the IND-TM (note: these are the same ANLs as shown in Table 4.2c for railway noise); or

 

·                      where the prevailing pre-Project noise level in the area is 5 dB(A) or more below the appropriate ANL, the total fixed source noise level must not exceed this pre-Project noise level.

 

4.2.20    The Corrected Noise Levels or CNLs (corrected for the presence of tonality, impulsiveness and intermittency) at the various NSRs due to fixed noise sources are normally developed in accordance with the IND-TM.  The noise impacts of the various fixed plant sources are considered to be cumulative. Therefore, in assessing the overall noise impact of fixed plant sources, the individual fixed source noise levels at each NSR are combined.

4.2.21    Once again, while assigning Area Sensitivity Ratings to the various types of areas which could contain NSRs, the IND-TM groups Country Parks together with rural areas and villages as having the highest inherent sensitivity to intrusive noise.  However, Country Parks themselves are not considered identical to other NSRs and furthermore, the EIAO-TM does not provide a specific noise limit for Country Parks.  Therefore, this EIA evaluates fixed plant noise levels at Country Parks qualitatively.

Fireworks Noise

4.2.22    There will be fireworks displays every evening at the Theme Park (Phase I and II).  As such, potential noise from the fireworks may impact on identified NSRs, namely Peng Chau and Discovery Bay.

4.2.23    At present, neither the EIAO-TM nor any of the other relevant technical memoranda address fireworks noise specifically. 

4.2.24    Due to the unique nature of fireworks noise, a limit of L_{Aeq, 15min} 55 dB at residential NSRs has been adopted for the noise created by evening fireworks displays at the Theme Park.  Details of the assessment criterion for fireworks noise have been addressed in the Theme Park EIA[2].

Public Transport Interchanges (PTIs)

4.2.25    Under the Noise Control Ordinance (NCO), PTIs are regarded as “public places” and as such, there is no statutory noise standards that may be applied to these facilities.  Although the predominant sources of noise associated with PTIs are road vehicles, road traffic noise standards are not the most appropriate criteria since road vehicle movements within PTIs represent a relatively fixed noise source compared with the free-flowing traffic on a normal road or highway.  As such, due to the nature of the noise source represented by PTIs and the characteristics of their noise emissions, the appropriate noise standards specified in the EIAO-TM, as reference, has been adopted for such facilities.

Road Traffic Noise

Traffic Noise Criteria

4.2.26    The EIAO-TM requires that road traffic noise levels outside the facades of any sensitive buildings which rely upon openable windows for ventilation should not exceed the criteria given in Table 4.2e.  Any measured or predicted road traffic noise levels which exceed these criteria will be considered to be an adverse environmental impact requiring mitigation consideration.

Table 4.2e - EIAO-TM Road Traffic Noise Criteria

Sensitive Uses	Road Traffic Noise L10, (1hr) (dB(A))(1)
Domestic Premises	70
Offices	70
Educational Institutions	65

Note:(1) Maximum permissible noise level assessed at 1 m from the external facade.

 

4.2.27    Though the EIAO-TM does not specify a limit for traffic noise levels received at a Country Park, road traffic noise impact assessment at the existing Lantau North Country Park and the Proposed Country Park Extension Area is provided and interpreted qualitatively. 

Criteria for Indirect Technical Remedies to Road Traffic Noise Impacts

4.2.28    Where feasible, direct technical remedies are to be recommended to reduce identified noise impacts where predicted traffic noise levels exceeds the criteria presented in Table 4.2e.  These measures include, but are not limited to, the following:

·                      noise barrier walls located along roadside and/or in central reserve area;

·                      noise enclosures or semi-enclosures;

·                      earth berms;

·                      noise reducing road surfaces (quiet pavements); and

·                      road decking or underpass construction.

4.2.29    Where direct technical remedies cannot be applied due to traffic or engineering constraints, or where such measures would not be wholly effective in eliminating noise impacts, the potential benefit of indirect technical remedies (i.e. improvement in noise insulation of windows and provision of air conditioning) will be assessed. Such indirect technical remedies to traffic noise impacts would be provided by the Project Proponent to qualified NSRs only as a last resort and in accordance with the Executive Council Directive, Equitable Redress for Persons Exposed to Increased Noise Resulting From The Use of New Roads.  For affected NSRs to be eligible for indirect technical remedies, the following three criteria from the Executive Council Directive must be satisfied:

·                      the predicted noise level from the “new” road, together with any other traffic in the vicinity, exceeds a specified noise level (i.e. 70 dB(A) L_{10, (1 hr)} for domestic premises and 65 dB(A) L_{10, (1 hr)}for educational institutions);

 

·                      the predicted overall noise level must be at least 1.0 dB(A) greater than the prevailing traffic noise level, i.e. the total traffic noise level which existed prior to the start of construction on the new or improved road; and

 

·                      the contribution to the increase in the predicted overall noise level from the “new” road must be at least 1.0 dB(A).

 

4.2.30    Here “new” roads  are considered to include those which, within the scope of the Project, are proposed to be constructed along totally new alignments, as well as those existing roadway sections which are to undergo major modifications.  Major modifications are considered to be those resulting in at least a 25% increase in the number of lanes, a substantial alteration in an existing alignment or a significant change in a relevant traffic parameter such as an increase in posted speed.  Roads that will remain either completely unchanged or that will undergo only minor modifications not satisfying the above conditions, will be classified as “unaltered”.

Helicopter and Aircraft Noise

4.2.31    Noise levels created at planned new developments by the operation of helicopters and aircraft in relation to the HKIA  are required to comply with the requirements set out in the EIAO-TM.  The relevant criteria are provided in Table 4.2f below.  The helicopter noise criterion is based on the maximum level (L_max) created during an individual helicopter noise event, while the aircraft noise criterion is based on the cumulative  noise exposure due to all aircraft operations as indicated by the airport’s most recent Noise Exposure Forecast (NEF) contours.

4.2.32    These noise criteria apply only to NSRs which rely on openable windows for ventilation.  They are to be evaluated at positions 1 m from the external sensitive facades of the NSRs.

Table 4.2f - EIAO-TM Noise Criteria for Helicopters and Aircraft

Noise Sensitive Uses	Helicopter Noise Limit (Lmax dB(A), 0700-1900 hours)	Aircraft Noise Limit (Noise Exposure Forecast, or NEF)
All domestic premises, hotel & hostels	85	25
Offices	90	30
Educational institutions	85	25

Note: These criteria apply only to land uses which will include buildings relying on openable windows for ventilation. 

 

4.3              Noise Sensitive Receivers

Existing Noise Sensitive Receivers / Area

4.3.1        After inspection of the Study Area and discussion of existing and planned land uses with the EPD and other concerned government agencies, it was agreed that five locations within the Study Area should be considered Noise Sensitive Receivers (NSRs) or Noise Sensitive Area (NSA) from the perspective of their potential exposure to the construction and operational noise from the proposed developments.  For the identification of NSRs at Peng Chau and Discovery Bay, reference to Plan No. L/1-PCN/4 and Layout Plan 6.0E1, where appropriate, have been made.  The locations of these NSRs/NSA (N1 to N5) are indicated in Figure 4.3a.  The characteristics of each of these NSRs/NSA are described below.

Peng Chau (N1)

4.3.2        Peng Chau is a sparsely populated island (largely village-type development) lying due south of the Penny’s Bay site.  Most of the village residences are located within the central portions of the island and will be shielded from noise originating in the Penny’s Bay area by the ridge line that runs along the northern end of the island.  However some relatively new low-rise apartment buildings are located on the north western tip of the island near Tai Lei where they will be directly exposed to noise from the construction and operation of the Phase I and II Theme Park.  Peng Chau has no conventional road system and is free from any other significant noise sources (i.e. no Influencing Factors).  This NSR is therefore assigned an Area Sensitivity Rating of “A”.

4.3.3        The location of the assessment point is shown in Figure 4.3b.

4.3.4        Due to large separation distances (about 2 km) and the very substantial terrain screening, Peng Chau would only be affected by the Theme Park and its associated developments, but not the other elements of the Project.

Discovery Bay (N2)

4.3.5        Discovery Bay is a large, but isolated, residential development on Lantau Island located south-west of the Penny’s Bay site.  It is accessible only by ferry and is presently free from any other significant noise sources. This NSR is also assigned an Area Sensitivity Rating of “A”.  Bearing in mind that a road tunnel linking Discovery Bay and Siu Ho Wan is under construction, it is anticipated that the future background noise at Discovery Bay would increase due to the presence of more road vehicles in the area.

4.3.6        The location of the assessment point is shown in Figure 4.3c.

4.3.7        Due to large separation distances (about 2 km) and the very substantial terrain screening to the west of Penny's Bay, Discovery Bay would only be affected by the noise from the International Theme Park and its associated developments, but not the other elements of the Project.

Luk Keng Tseun (N3)

4.3.8        Luk Keng Tsuen is  a small village on the north shore of Lantau Island containing only 19 occupied residences.  This NSR is located adjacent to an Eco Park proposed under Draft RODP but is also separated by only about 400 m of water from the existing Airport Railway and the North Lantau Highway.  This village-type NSR is considered to be “directly affected” by the noise from this expressway and therefore has been assigned an Area Sensitivity Rating of “B”.

4.3.9        The location of the assessment point is shown in Figure 4.3d.

Lantau North Country Park (N4)

4.3.10    The other potentially noise-sensitive land use will be the Lantau North Country Park lying at around 7 km to the southwest of the Penny’s Bay area.

4.3.11    The location of the assessment point (N4-a) is shown in Figure 4.3e.

4.3.12    Owing to large separation distances (for example around 7 km between the Lantau North Country Park and the development area in this Project)  and the substantial multi-layers of terrain screening the potential noise source in this Project, it is envisaged that the Lantau North Country Park is unlikely to be subjected to construction and operational noise impact.

Tso Wan (N5)

4.3.13    Tso Wan is  a small village along the eastern coastline of Lantau Island.  The area is currently undeveloped and generally rural in nature. The existing Tso Wan area has no conventional road system and is free from any other significant noise sources (i.e. no Influencing Factors).  This NSR is therefore assigned an Area Sensitivity Rating of “A”.  Whereas in the future, the operation of Route 10-NLYLH and the recreational development proposed at the eastern reclamation area of Tsing Chau Tsai under this Project will substantially alter the character of the area.  With a direct influence from the planned Route 10-NLYLH highway, the Area Sensitivity Rating will be “B”.

4.3.14    The location of the assessment point is shown in Figure 4.3f.

4.3.15    This NSR will be assessed for construction noise impact only since operational noise impact predominantly from the planned Route 10-NLYLH has already been assessed in the Route 10 EIA Final Assessment Report[3] (herein after refer as Route 10 EIA Report).  However, for completeness, road traffic noise levels from the planned Route 10 - NLYLH on Tso Wan has also been presented in this Report.

Planned Noise Sensitive Receivers

4.3.16    According to the Draft RODP, the following three planned sensitive uses are identified from the perspective of their potential exposure to construction and operational noise from the proposed developments: 

·                      Proposed Lantau North Country Park Extension Area (N4’);

·                      Tso Wan Village Expansion Area,  (N6);

·                      Planning Area 4A to 4C in Siu Ho Wan for R2 uses (N7);

 

4.3.17    In addition, the following three planned sensitive uses located in the vicinity of the Siu Ho Wan proposed development will be built before the construction of the Siu Ho Wan development commence and hence are included in the construction noise impact assessment.

·                      Planning Area 38 in Tai Ho for R2 uses (N8);

·                      Planning Area 10 above Siu Ho Wan MTRC Depot for R2 uses (N9); and

·                      Planning Area 56 in Tai Ho East for school development (N10).

 

4.3.18    The location of these planned NSRs (N4’, N6 - N10) is shown in Figure 4.3a and Figure 4.3e.

Proposed Country Park Extension Area (N4’)

4.3.19    The Proposed Country Park Extension Area, located to the west of Penny’s Bay, will be a planned noise sensitive land use.  This land use, which is in its natural state and contains only a few footpaths overlooking the Theme Park site from the hillside above the western shore of Penny’s Bay.  It is currently exposed only to noise from natural sources, aircraft, ferries and, to a limited degree, the existing shipyard and CLP power station at Penny’s Bay.

4.3.20    It should be noted that Country Parks are not themselves considered to be NSRs under the IND-TM and no specific noise limits are provided for Country Parks in the EIAO-TM.  For the purpose of describing the potential project related noise environments over the Proposed Country Park Extension Area, three evaluation sites (N4’-b, N4’-c and N4’-d) have been selected.  The location is indicated in Figure 4.3e.

Tso Wan Village Expansion Area (N6)

4.3.21    By the time the Tso Wan Village Expansion area is occupied, it will be “directly affected” by road traffic noise from the planned Route 10-NLYLH highway.  The area will be assigned an Area Sensitivity Rating of “B”.

Tai Ho/Siu Ho Wan Area (N7 - N10)

4.3.22    It is understood that highrise residential developments are proposed in Tai Ho Area.  The planning areas in the Tai Ho / Siu Ho Wan area will be “directly affected” by road traffic from Road P1 and North Lantau Highway.  An Area Sensitivity Rating of “C” is therefore assigned for the planned developments.

4.3.23    Representative assessment points were identified for the above existing and planned NSRs and they are shown in Table 4.3a below.

Table 4.3a - The Location of Representative Assessment Points

Noise Sensitive Receiver	Assessment Point	Location	Area Sensitivity Rating	Ground Level mPD	Number of Storey	Sensitive Uses
Peng Chau	N1-a	Sea Crest Villa	A	6	3	Residential
Discovery Bay	N2-a	Crestmont Villa	A	15	2	Residential
Luk Keng Tsuen	N3-a (construction)     N3-b to N3-d (operation)	Village house at the northeastern tip of Luk Keng Tsuen   Village house along the southeast coastline of Luk Keng Tsuen headland	B       B	6       6	2       2	Residential       Residential
Lantau North Country Park	N4-a	North of Mui Wo	n/a	200	n/a	Country Park
Proposed Country Park Extension Area	N4’-b	South of Yam O Interchange near Tin Shui Tau	n/a	120	n/a	Country Park
	N4’-c	West of GTP	n/a	140	n/a	Country Park
	N4’-d	West of Theme Park Phase I near Sze Pak	n/a	120	n/a	Country Park
Tso Wan	N5-a (construction)	Village house along the coast	A	6	2	Residential
Tso Wan Village Expansion Area	N6-a to N6-c (operation)	Village houses to the west of the existing village	B	24-50	2	Residential
Planning Area 4A to 4C in Siu Ho Wan	N7-1 and N7-39 (operation)   N7-2 to N7-38 (operation)   N7-50 to N7-56 (operation)	Lowrise buildings along the coast     Highrise buildings at the development     Schools at the junction of Road P1 and Access Road to the development	C       C       C	6       6       6	9       25       7	Residential       Residential       Educational
Planning Area 38 in Tai Ho	N8-a (construction)	Nearest building facing Siu Ho Wan Development	C	6	30	Residential
Planning Area 10 above Siu Ho Wan MTRC Depot	N9-a (construction)	Nearest building facing Siu Ho Wan Development	C	6	26	Residential
Planning Area 56 north of Siu Ho Wan MTRC Depot	N10-a (construction)	School	C	6	7	Educational

 

4.3.24    The location of assessment points of the planned NSRs are shown in Figures 4.3f and 4.3g.

4.3.25    Based on the Draft RODP, uses proposed for other developments under the NLDFS will not be noise-sensitive and hence are not regarded as NSRs in this assessment.  These include:

·                      The Tsing Chau Tsai East reclamation area; and

·                      The Northshore developments, including the Theme Park Gateway, the Tourist and Convention Village and the Technodrome.

 

 

Noise Sensitivity of the Theme Park

4.3.26    HKITP has indicated that, based on the land uses associated with their other operational theme parks, none of the types of potential noise sensitive receivers identified in Annex 13 of the EIAO-TM will be located within either phase of the Theme Park.  Furthermore, it has been agreed with HKITP that Theme Park visitors should not be considered to represent noise sensitive receivers from the perspective of exposure to noise created by the Theme Park operations, including fireworks, or internal site traffic.

4.3.27    No operational noise (including fixed plant, road and rail traffic, helicopter and aircraft) assessment has therefore been conducted for the Theme Park itself.

Existing Noise Environments at NSRs

Peng Chau (N1)

4.3.28    As was shown in Section 4.2.3, the EIAO-TM limits planning noise levels from fixed plant sources to either 5 dB(A) less than the ANL or the pre-Project background noise level, whichever is lower.  It is therefore necessary to establish typical pre-Project noise levels at key NSRs, particularly where there is reason to expect they may be lower than the ANL - 5 dB(A).

4.3.29    Given the isolated, village nature of Peng Chau, it was suspected that, during the daytime and evening, pre-Project noise levels at Peng Chau would be less than the appropriate ANL-5 dB(A) ,  i.e. 60 - 5 = 55 dB(A). Therefore,  continuous noise monitoring was carried out as part of this EIA Study over three periods totalling 28 hours at the Sea Crest Villa near Tai Lei on the north-west shore of Peng Chau facing Penny’s Bay.  The monitoring location is shown in Figure 4.3b .  This monitoring took place in mid November to early December 1999, and for comprehensiveness, covered both daytime and evening periods in weekday and weekend.  A Bruel & Kjaer Type 2236 integrating sound level meter (Type 1 standard) was used.  The meter was calibrated before and after each noise monitoring period using a Bruel & Kjaer Type 4231 acoustic calibrator.  

4.3.30    Pre-Project noise levels on the north-west shore of Peng Chau were controlled by natural sources (wind and waves) and were found to be quite consistent during both the daytime and evening.  Over the Saturday evening and Thursday daytime and evening monitoring periods, the average noise levels obtained were respectively L_Aeq 49.9 and 49.0 dB(A).  The detailed results of these noise measurements are contained in Annex C1, Table C1.1a-C1.1b herein.  Being slightly more than 5 dB(A)  below the daytime and evening planning ANL for this NSR (i.e. L_{Aeq, 30min}  60 dB) , these pre-Project noise levels then establish a limit of approximately 50 dB(A) for noise received at Peng Chau during the daytime and evening due to fixed plant sources at the Theme Park and its associated developments.

4.3.31    Since pre-Project noise levels at Peng Chau are controlled largely by natural sources (wind and waves), it is expected that these levels would be quite consistent from day to day.  On the two monitoring days, winds were quite light so that wave noise is not expected to have been unusually high.  Similarly, this noise would not typically be expected to decrease significantly during the night-time hours.  It is therefore considered that the fixed plant noise limit for Theme Park and associated developments between 2300 hours (the beginning of “night-time”) and 0200 hours  (the planned closing of the Theme Park) should be the appropriate ANL -  5 dB(A), that is 50 -  5 = 45 dB(A). 

Discovery Bay (N2)

4.3.32    It has been conservatively assumed that the background noise levels at waterfront residential locations at Discovery Bay would be the same as measured at Peng Chau.  The Theme Park fixed plant noise limits would then also be the same as for Peng Chau, namely L_{Aeq, 30min}  50 dB during the daytime and evening and 45 dB during the night-time.

4.3.33    Given that the nature of development in Discovery Bay is similar but slightly more intensive to that in Peng Chau, it was predicted that the pre-Project noise levels at Discovery Bay would be less than the appropriate ANL-5 dB(A), i.e. 55 dB(A).  To ascertain this, continuous noise monitoring was also carried out with the same monitoring specifications  and procedures adopted in the Peng Chau monitoring.  The monitoring location is shown in Figure 4.3c .  This monitoring took place in December 1999 and January 2000, again covering both daytime and evening periods in weekday and weekend.

4.3.34    Pre-Project noise levels at Discovery Bay were found to be quite consistent during both the daytime and evening.  The average noise levels obtained for the daytime and evening monitoring periods were around 53 dB(A) and 52 dB(A) respectively.  It could be seen that the ambient noise levels at Discovery Bay are generally 2 or 3 dB higher than those of Peng Chau.  The higher population density, and thereby more community activities, at Discovery Bay is the likely contributing element to this difference.  The detailed results of these noise measurements are contained in Annex C1, Table C1.2a-C1.2b. 

4.3.35    Being approximately  3 dB(A) below the daytime and evening planning ANL for this NSR (ie.L_{Aeq, 30min} 60-5 dB), these pre-Project noise levels then establish a limit of approximately 52 dB(A) for noise received at Discovery Bay during the daytime and evening due to fixed plant sources at the Theme Park.  It is therefore considered that the limit for Theme Park fixed plant noise levels between 2300 hours and 0200 hours should be the appropriate ANL - 5 dB(A), that is 50 - 5 = 45 dB(A).

4.3.36    As pointed out in Section 4.3.1, it is anticipated that the future background noise at Discovery Bay would increase due to the presence of more vehicles in the area following the opening of the road tunnel linking Discovery Bay with Siu Ho Wan.

Luk Keng Tseun (N3)

4.3.37    Due to the proximity of this village to two major noise sources represented by the North Lantau Highway, MTRC Tung Chung Line and Airport Express Line, it is considered that the planning noise limit for fixed noise sources associated with the Project development will, as required by the EIAO-TM, be established by the appropriate ANL - 5 dB(A).  Given that this NSR has been assigned an Area Sensitivity Rating of “B” with the proposed major developments along the northern shoreline of Lantau, the appropriate limits are L_Aeq,30min  60 dB during the daytime and evening and 50 dB during the night-time.

4.3.38    Given the current rural nature of the area, an Area Sensitivity Rating of “B” has been assigned for construction noise assessment purposes.

4.3.39    Pre-Project noise levels at the village house closest to North Lantau Highway was found to be of L_{Aeq 30 min} 62 dB measured in November1999 for the Theme Park EIA.

Lantau North Country Park (N4)

4.3.40    This land use is in essentially its natural state and contains only a few footpaths.  It is currently exposed only to the noise from natural sources and aircraft.

4.3.41    No noise monitoring was done at the Country Park.  However, since neither the EIAO-TM nor the other technical memoranda on noise specify noise limits for Country Parks, the establishment of pre-Project background noise levels was not considered necessary at this location.  However, it is expected that the pre-Project noise levels over this undeveloped land will be similar to, or somewhat lower than, those measured on the north-west shore of Peng Chau. 

Tso Wan (N5)

4.3.42    Due to its rural nature, it has been conservatively assumed that the background noise level at Tso Wan would be similar to what has been measured at Peng Chau, ie. around 50 dB(A).  Similar to Peng Chau, this background noise level is more than 5 dB(A) below the daytime and evening planning ANL for this NSR (i.e. L_{Aeq, 30 min} 60-5 dB).  Therefore, this pre-Project noise levels then establish a limit of approximately 50 dB(A) for the noise received at Tso Wan during the daytime and evening due to fixed plant sources at the proposed development area.  The noise limit during night-time would be ANL - 5 dB(A), that is 50 - 5 = 45 dB(A).

4.4              Assessment Methodology

Construction Noise

Construction During Unrestricted Hours

4.4.1        The assessment of the potential noise impacts due to development proposed in the Draft RODP and the CKWLR construction works to be carried out during unrestricted hours (0700 to 1900 hours Monday to Saturday) has been undertaken in accordance with the GW-TM and Annex 13 of the EIAO-TM.  The general methodology is as follows:

·                      locate all representative NSRs that may be affected by construction noise from each major construction site/zone;

 

·                      determine plant team (groups of active PME) that will be required for each major construction activity based on the proposed plant inventories;

 

·                      assign a sound power level (SWL) to each PME based on the GW-TM or other appropriate sources;

 

·                      locate the “notional source position” of each major construction site;

 

·                      calculate distance correction factors based on the distance between the notional noise source position of each work site and each NSR;

 

·                      apply corrections as appropriate for such factors as noise screening (shielding) and reflection, and

 

·                      calculate construction noise levels at NSRs in the absence of any mitigation measures.

 

4.4.2        For construction sites of large sizes, the notional source position has been taken to be a point 50 m from that point on the site boundary measured along the line between the approximate geographical centre of the site and the point on the site boundary nearest to the NSR.

4.4.3        Based on the proposed construction programme (schedule) and PME teams  (Annex A and Annex C2, Table C2.1) for each major construction activity, spreadsheets have been developed to facilitate the calculation of construction noise levels at the NSRs.  Moreover, in view of the large distances between the construction sites and some of the NSRs, the effect of atmospheric absorption has been included in the calculation.  Using these spreadsheets, both the individual and cumulative construction noise levels from individual and all concurrent construction activities which are considered to be significant at a given NSR have been calculated.

4.4.4        Where the line of sight between a specific construction zone and a specific NSR will be consistently and substantially interrupted by natural terrain features, construction noise created within that zone has not been included in the calculation of overall construction noise levels at that NSR.  These overall noise levels would tend to be controlled by other major construction activities, which do not benefit from terrain shielding and are to proceed concurrently with the shielded activity.

4.4.5        The spreadsheets summarising the plant teams and schedules for each major construction activity related to the NLDFS Development including the CKWLR are presented in Annex C2, Table C2.1.  The predicted noise levels due to individual construction activity and the resulting cumulative construction noise levels at each NSR are presented in Annex C3a, Tables C3a.1-C3a.7.  As CKWLR is classified as a Schedule 2 Designated Project itself under the EIAO, the predicted noise levels solely from the construction of CKWLR is presented as a separate row under the spreadsheets as presented in Annex C3a, Tables C3a.1-C3a.7

4.4.6        Potential construction noise impacts during unrestricted hours have been quantified by comparing the predicted noise levels with the EIAO-TM daytime construction noise limits as given in Section 4.2.1.  

4.4.7        Where projected construction noise levels at a NSR exceed the EIAO-TM limit, mitigation measures are to be considered.  These measures may include the use of quiet plant, the erection of purpose-built noise barriers (where appropriate) and the limitation of the use of particularly noisy plant in a particular location or within a particularly busy construction period.

Construction During Restricted Hours

4.4.8        With the proposed construction programme, construction activities will generally be carried out on a 16-hour day (i.e. 0700 - 2300 hours) and 24 working days per month basis.  Night-time construction activities will be carried out for the reclamation works at the Penny’s Bay site for the Theme Park Phase I development.  The dredging plant which will be operating on a 24-hour day and 7 days per week basis includes the Trailer Suction (TS) dredger, Cutter Suction (CS) dredger and grab dredger.  In view of the location of the construction site, only Peng Chau (N1) and Discovery Bay (N2) will be affected by the night-time activities and therefore included in this assessment while other NSRs are either located at a remote distance or benefited from terrain shielding.

4.4.9        As indicated in Section 4.2.1, for any construction works planned during the restricted hours, it will be the responsibility of the Contractor to ensure compliance with the NCO and the relevant technical memoranda.  In such cases, the Contractor will be required to submit CNP applications to the Noise Control Authority and abide by any conditions stated in the CNP, should one be issued.  Therefore the potential noise impacts of construction works proposed within restricted hours are not formally assessed within this EIA. However, in order to facilitate the efforts of the Project proponent to avoid and/or mitigate any potentially adverse project noise impacts, noise levels from construction activities planned for restricted hours have been predicted at the NSRs.  The PME proposed to be operated during the restricted hours and the predicted noise impact are shown in Annex C3a, Tables C3a.1-C3a.7 (evening time from 1900 to 2300 hours and general holidays from 0700 to 2300 hours) and Annex C4, Tables C4.1-C4.2 (night-time from 2300 to 0700 hours) respectively.

4.4.10    Generally, construction works during restricted hours are not recommended.  This is to avoid annoyance to residents during these hours.  However, in view of the time constraints for the completion of certain construction activities, the undertaking of certain construction activities during restricted hours is likely to be required.

4.4.11    It should be noted that, as pointed out previously, despite any description or assessment made in this Report on construction noise aspects, there is no guarantee that a 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 TM issued under the NCO.  The Noise Control Authority will take into account of the then prevailing conditions/situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP.

4.4.12    As addressed in Section 4.2.1, both the GW-TM and the EIAO-TM have not provided any construction noise limits for Country Parks and therefore in this EIA, construction noise levels at the existing Lantau North Country Park and the Proposed Country Park Extension Area have been estimated in relative terms and addressed qualitatively.

Railway Noise

Airport Express Line and Tung Chung Line

4.4.13    Operational trains of Airport Express Line (AEL) and Tung Chung Line (TCL) are potential sources of noise within the context of Northshore Lantau areas.  In view of the Draft RODP, potential noise sensitive uses likely to be affected by AEL and TCL include Luk Keng Tsuen and Planning Areas 4A to 4C in Siu Ho Wan.    

4.4.14    With reference to the Lantau and Airport Railway Environmental Impact Study ^([4]), the preferred service pattern of AEL would be a maximum of twelve return services per hour by year 2012.  The train service of TCL would vary between the peak hour periods and off-peak time periods.  Timetable of AEL and TCL train services are detailed in Table 4.4a below. 

Table 4.4a - Lantau and Airport Railway Service Patterns - Year 2012

 

4.4.15    The present train length of TCL train is approximately 161 m (7 car); and for AEL is 161 m (7 car).  In the future, the train length of TCL train will be increased to 185 m (8 car); and 232 m for AEL (10 car).  The maximum operating speed of the AEL trains and TCL trains is 135 kph.  A maximum A-weighted reference noise level (L_Amax) of the Electric Multiple Unit (EMU) trains of 86 dB(A) running at 135 kph on ballasted track supporting continuously welded rail measured at a distance of 25 m was used in the assessment.

Penny’s Bay Rail Link

4.4.16    Reference has been made to the Penny’s Bay Rail Link Environmental Impact Assessment (PBRL EIA) ^([5]) as part of the Theme Park EIA Final Report, and relevant information is duplicated below for ease of reference.  Operational trains running on PBRL would be potentially affecting the nearby noise sensitive uses.  Luk Keng Tsuen is the nearest NSR to this rail link and the noise level as well as the cumulative noise level have been predicted at this NSR in PBRL EIAStudy.  

4.4.17    The maximum train service of PBRL would be fifteen return services per hour between Yam O and Penny's Bay.  Two EMU trains will operate simultaneously utilising a passing loop in Penny's Bay.  Although 4-car trains will be operated during the initial operation, longer term capacity may require the employment of 8-car trains and this has been adopted as a worst case in PBRL EIA Study.  The train length will be 184 m (8 car) and the maximum operating speed will be 80 kph.  The maximum A-weighted noise level (L_Amax) of the rolling stock will be maintained within a reference noise level at 25 m of 89 dB(A) at 130 kph on ballasted track supporting continuously welded rail.

Assessment Methodology

4.4.18    The acoustic modelling of rolling noise from the operational trains has been undertaken using ERM's in-house software, ERM Rail Noise Model (ERMRNM).  This software employs the methodology described by the Noise Advisory Council's A Guide To The Measurement and Prediction of the Equivalent Noise Level (Leq).  This modelling software as well as the prediction methodology have been adopted in the PBRL EIA Study.  Below is an example to illustrate the prediction of L_Aeq,30min noise levels based on a reference L_Amax source term for the rolling stock:

·                      localised variation in L_Amax noise due to train speed:

                D_v = 30×Log₁₀ (v₁/v₂) dB;

 

·                      integration of theoretical time history for train rolling noise with dipole directivity ^([6]) : SEL (sound exposure level) = L_Amax + 10×Log₁₀(l/v) + 10.5 - 10×Log₁₀((4D/4D² + 1) + 2 tan^-1(1/2D)) dB, where:

 

l = train length (m)

v = train speed (kph)

d = distance from track (m)

D = d/l

 

·                      30-minute equivalent continuous energy level (L_Aeq) = SEL + 10×Log₁₀ (n_i/1800) dB, where :

 

n_i= number of trains with identical noise characteristics

 

correction for distance:

 

                      D_d = 10 x Log₁₀(25/d) dB, where

 

                      d = distance between source and NSR in m

 

4.4.19    Additional relevant procedures are incorporated for the following:

·                      user definable source term in third octaves;

·                      a 2.5 dB(A) reflection correction at the facade of the receiver;

·                      calculation of atmospheric absorption of noise for NSRs located over 300 m away from the alignment;

·                      barrier shielding calculation in third octaves based on the methodology developed by Maekawa as follows:

 

         DL_{absorptive barrier} = 7 dB + 20 log[(2pN)^½/(tanh(2pN)^½)] dB - PL(N)

 

where PL is the difference in barrier attenuation between an infinite line source and a point source as a function of the maximum Fresnel Number, N.

 

         N = 2 (P.L.D.)/ l

 

where P.L.D. is the Path Length Difference between the direct and diffracted sound paths; and l is the wavelength of sound.

 

4.4.20    Topographical features between the railway and the NSRs have been included in the modelling. 

Fixed Plant Noise

General

4.4.21    A variety of fixed plant noise sources will be associated with this Project including the operation of the Theme Park (Phase I and II), Theme Park (Phase III) Extension, fireworks displays, the recreational development at Tsing Chau Tsai East, the sewage pumping station at Penny’s Bay, Water and Sewage Treatment Works and North Lantau Transfer Station near Siu Ho Wan, vehicle parking areas, the proposed PTIs at Yam O and Penny’s Bay and CLP GTP at Penny’s Bay.  For some of these facilities, empirical at-source noise level data are available, either from previous studies of similar installations in Hong Kong or from outside information sources.  In predicting the noise levels that will result at the various NSRs due to fixed plant sources, conservative approaches have generally been taken so as to compensate for any uncertainty which may exist regarding the source noise levels created by these facilities.

4.4.22    In estimating the noise levels to be created at the NSRs due to the various fixed plant sources, the procedures described in the IND-TM were followed, augmented, where required, with basic acoustical principles.  Since the procedures followed in evaluating the noise from each fixed source tended to be somewhat unique, they are described in turn below:

The Theme Park

4.4.23    The major fixed source of noise associated with the proposed developments in the Draft RODP is expected to be the Theme Park.  As shown in Figure 4.1a, the Theme Park will consist of a western section (Phase I),  an eastern section (Phase II) and a farther eastern section (Phase III Extension).  The Phase I and Phase II Theme Park sections are separated by a central Retail, Dining and Entertainment (RD&E) corridor and linked by “Main Street”. For worst-case noise impact assessment, full operation of the Theme Park have been taken into account.

4.4.24    While HKITP has supplied the general arrangement of the attractions to be located within the Phase I Theme Park (i.e. Toontown, Fantasyland, Tomorrowland etc, described in Section 2.7.4) and has indicated that additional similar, but as yet unspecified, attractions will be located in Phase II, noise source data for these individual Theme Park zones are not available.  It is therefore necessary, on balance preferable, to base the noise emissions of the future Theme Park on the overall noise emissions measured at another major international theme park.  Towards this end, HKITP has provided average noise levels (L_Aeq’s) measured over 30 minute periods at three unshielded locations around the perimeter of the Anaheim, California Disneyland.  These measurements, the details of which are included in Annex C5, revealed that average perimeter noise levels ranged from L_{Aeq, 30min} 67 to 69 dB.

4.4.25    The Anaheim Disneyland measurement which yielded the highest average noise levels was made approximately 100 m from the “Fantasmic” show site while the show was in progress.  This is a relatively new show that features loud music and special audio and visual effects.  However, given the continuing trend towards higher levels of amplified music and special effects at both motion picture theatres and amusements parks, the potential exists for a new Theme Park to be somewhat noisier than the Anaheim facility.  To reflect this potential, the reference noise source level for the Hong Kong Theme Park has been taken to be L_{Aeq, 30min} 75 dB at the Theme Park perimeter (i.e. this is the highest average noise level expected to be measured at any unshielded position along the top  of the 9 m high perimeter earth berm).

4.4.26    EIA support information received from HKITP has indicated that the two Theme Park phases are intended to operate until midnight while the RD&E area is planned to be open until 0200 hours.  It can be assumed that Theme Park noise emissions are essentially constant throughout its hours of operation apart from the fireworks shows. Therefore, for planning purposes, Theme Park noise impacts must be evaluated against the night-time noise limit specified in the EIAO-TM, namely 5 dB(A) less than the night-time ANL, or L_eq,30min  45 dB(A) for residential NSRs such as Peng Chau and Discovery Bay.

4.4.27    In order to assess the noise levels to be created at NSRs by operations within the Theme Park boundaries, the two major park areas (Phases I and II) were considered to be represented by circular zones, each 700 m in diameter.   Theme Park noise sources were assumed to be uniformly distribured throughout these circular zones such that a noise level of L_Aeq 75 dB was generated at all positions on the park perimeter.  Given the large size of these noise source zones, an assumption that all of the sound energy was emitted from a single point at their centres would have significantly overestimated the Sound Power Level (SWL) emitted by the Theme Park.  On the other hand, assuming that the “notional centre” of each Theme Park noise source zone was located 50 m inside its perimeter boundary (as done for construction noise in the GW-TM), would have significantly underestimated the total SWL in this situation.  Therefore, to more realistically represent these large distributed source zones, each 700 m diameter circle was sub-divided into nine parts of equal area and assumed equal sound power.

4.4.28    It was then possible to calculate the total Theme Park SWL that would be required to produce L_eq 75 dB(A) at any point on the perimeter of the 700 m  diameter source zone.  Applying this same SWL to each of Theme Park Phases I and II, the combined Theme Park sound level at the NSRs were calculated in the standard manner (see Annex C6).  For the distant Peng Chau and Discovery Bay NSRs, the equivalent acoustic centres of the two Theme Park source zones are very close to their geometric centres.  The computation was done in accordance with International Standard ISO 9613-2: 1996(E), Acoustics - Attenuation of Sound During Propagation Outdoors, Part 2.

4.4.29    Because of the large source-to-receiver distances involved (up to 3.2 km), the attenuation of Theme Park operational noise with distance from the acoustic centres of the two source zones was calculated taking into account both geometric spreading and atmospheric absorption.  The atmospheric absorption rate was based on the International Standard ISO 9613-1: 1993(E),  Acoustics - Attenuation of Sound During Propagation Outdoors, Part 1.  Average atmospheric conditions of 20° C and 70% relative humidity were assumed in selecting atmospheric absorption rates.  This resulted in overall atmospheric absorption effects of 8 to 9 dB(A) over distances of 2.5 to 3.2 km.

4.4.30    As shown in Figure 4.1a, the two phases of the Theme Park will be almost entirely surrounded by 9 m high earth berms.  These berms are intended to visually screen Theme Park visitors from the outside world but will also act to shield the outside world from Theme Park noise.  In addition, there will be a number of hotels constructed along the waterfront to the south of the Theme Park, thereby augmenting the screening effects of the earth berms to some degree.  Since neither the heights and locations of the dominant Theme Park noise sources nor of the hotels are known, it is then not possible to accurately assess the net noise shielding effect of the earth  berms and hotels.  While it may be concluded that this effect would be very substantial (up to 15 dB) for source and receiver positions near the ground and close to a berm, over the large distances to NSRs at Peng Chau and Discovery Bay, turbulence and other atmospheric effects may be expected to limit the average noise reduction provided by any practical noise barrier to about 8 to 10 dB(A).  This typical screening effect was therefore applied at Peng Chau and Discovery Bay.

4.4.31    The detailed characteristics of the many noise sources that will be associated with normal Theme Park operations and contribute to the overall character of Theme Park noise are not known.  However, based on observation at similar parks and on professional judgement, it is considered that the overall noise output of such a facility should not be characterised as being tonal, impulsive nor intermittent as defined in the IND-TM.  Therefore, no corrections for these undesirable noise characteristics have been applied.

4.4.32    As for the possible Phase III Extension, it is recognised that there are not even preliminary plans associated with this concept.  It has therefore been assumed that Phase III Extension would have a L_eq level of 75 dB(A) at the perimeter but would not open beyond 2300 hours.  Thus night-time assessment is not required.

Fireworks Displays

4.4.33    As discussed in Section 4.2.4, in the absence of any specific limit for fireworks noise within the various Hong Kong noise regulations, a limit of L_Aeq,15min  55 dB has been adopted for the evening fireworks displays to be staged at the Theme Park.  Information provided by HKITP indicates that, because fireworks must be restricted to mid-level displays (100 m maximum height), a single display would not likely be visible from Phase I and Phase II of the Theme Park.  It is therefore considered that it will ultimately be necessary to employ two fireworks launching sites, one at the western end of Phase I and one at the eastern end of Phase II.  The shows at these two sites would be staged separately likely one starting at 2100 and one at 2130 hours. 

4.4.34    While the fireworks displays to be presented at the Theme Park have not yet been developed in any detail, source noise data for such displays has been obtained based on measurements conducted by HKITP, the EPD and the EIA Study Team in November, 1999 during a specially-staged demonstration of the range of fireworks types that could be considered for use in Hong Kong.  On this occasion, the maximum noise levels related to individual fireworks items and event noise level created by each type of fireworks were measured at distances of 500 and 800 m from the launch site.  The noise output of a combination of fireworks elements that might reasonably be expected to be used are computed.   The individual noise contributions of these elements have been combined and their average sound energy level computed over the estimated 5 minute duration of the show (see Annex C7).

Recreational development at Tsing Chau Tsai East

4.4.35    Potential noise impact from the recreational activities at Tsing Chau Tsai East reclamation area on nearby NSRs, namely existing Tso Wan and Tso Wan Village Expansion Area are evaluated and addressed in Section 4.5.3.

Penny’s Bay Gas Turbine Plant (GTP)

4.4.36    CLP’s GTP at Penny’s Bay has been in intermittent operation for several years and as such is not a component of the Project.  However, the noise produced by its operation will add, to some degree, to the noise levels created at NSRs by the various Project fixed plant noise sources.  As the power station is only in intermittent operation, regular noise monitoring data are not available.

4.4.37    The EIA of Gas Turbine Plant at Penny’s Bay (1990)[7] has recommended noise control measures for achieving 75 dB(A) emission at the site boundary which have been followed by the power company.  This reference noise level has thus been used for our assessment of the potential noise impact from the GTP on those NSRs at which power plant noise might reasonably be expected to be audible.  These projections have been based only on the spherical spreading of sound waves with distance and on facade or hillside reflection as appropriate.

Utility Yard (Sewage Pumping Station)

4.4.38    The major noise source within the Utility Yard to be constructed to the west of the vehicle parking area will be the sewage pumping station, as shown in Figure 4.1a.  Sewage pumping stations are not uncommonly located within or near residential areas.  Such situations would then see NSRs located within short distances of the pumping station.  Although the capacity of the proposed sewage pumping station will not constitute a Schedule 2 Designated Project under the EIAO-TM, its operation will have to meet the night-time planning noise limits of from 45 to 55 dB(A) at the nearest NSR.  These levels can generally be met by enclosing the pumping facilities in a building and applying appropriate silencers to the intake and exhaust air openings. 

Fixed Plant near Siu Ho Wan

4.4.39    Potential noise impacts from the existing Water and Sewage Treatment Works near Siu Ho Wan on  nearby NSRs, (i.e. the proposed residential development at Siu Ho Wan) have been assessed and the results are presented in Section 4.5.3.

4.4.40    As the North Lantau Transfer Station near Siu Ho Wan is a potential noise source, impacts from its operation on NSRs have been assessed and the results are presented in Section 4.5.3.

Fixed Plant of Penny’s Bay Rail Link

4.4.41    Sources of fixed plant noise associated with the PBRL has been presented in the PBRL EIA Report.  These include noise from the transformers and substations for power supply to the railway, ventilation building proposed at the northern and southern tunnel portals, and the noise from train washing facilities located close to the Penny's Bay Rail Station.  While, details of the assessment are presented in the PBRL EIA Report, results are presented in Section 4.5.3.

Public Transport Interchanges (PTIs)

4.4.42    Because of the large setback distances that will exist between the Penny’s Bay PTI and the nearest NSRs at Peng Chau and Discovery Bay, and also between the Yam O PTI and NSRs at Luk Keng Tsuen, no significant noise impact was anticipated from these noise sources.  However, the noise levels to be expected at these NSRs were predicted using basic acoustical principles and based on the SWL measured recently at some of Hong Kong’s larger PTIs (e.g. Kwun Tong and Shing Tak Centre).  Sample calculation on the projected noise impacts from the PTIs is provided in Annex C9.

Potential Fixed Plant Noise from Proposed Ventilation Building

4.4.43    Ventilation buildings have been proposed at the Yam Tsai Tunnel for air quality purpose.  As such, noise impact from the ventilation shaft on the closest NSR, namely Luk Keng Tsuen has been assessed.

Cumulative Noise Impact from all Fixed Plant Sources

4.4.44    While noise assessment of each fixed plant source on NSRs, where appropriate, has been evaluated, cumulative noise impact from all fixed plant sources are also assessed.

Road Traffic Noise

Calculation of Road Traffic Noise Levels

4.4.45    As specified in the Study Brief,  the road traffic noise calculations carried out  in this Project follow the methodology described in Calculation of Road Traffic Noise (CRTN), published by the UK Department of Transport in 1988.  The computer software used to implement this methodology was HFANoise, as developed by Halcrow Fox utilising a “links and nodes” representation of the road network and noise receiving environment.

4.4.46    The modelling scheme for the determination of traffic noise levels is based upon a digitised representation of the existing and proposed roads within the spatial scope of the Project.  Each of the road networks are divided into discrete road segments having homogeneous traffic conditions and road layout characterisation.  For each such segment, the key characteristics of a road link with respect to its traffic noise emissions are defined; namely its traffic volume, composition, average vehicle speed, laning and horizontal and vertical alignment.  Road surfaces were taken to be of pervious material in all roads assessed in this Project.  Maximum road capacity were used in the modelling of future road traffic noise levels.  The traffic flow, speed and percentage of heavy vehicles for each road link are shown in Figure 2.9b.

4.4.47    All roads that would be subject to significant variation and those which remain unaltered or subject to minor changes were classified in the HFANoise model as “new “ and “unaltered” respectively with reference to the Study Brief.  This has enabled the model to calculate noise levels classified by road link description according to the Study Brief and the Executive Council Directive.  The roads classified as “new” in this Study are  Road P1, Road P2, CKWLR, Route 10, the Resort Roads and all the associated slip roads.  North Lantau Highway was classified as “unaltered” road.

4.4.48    In assessing the attenuation of traffic noise with distance from the roadways, a worst-case, hard ground attenuation rate was assumed throughout the Study Area.   While this assumption may be conservative in some local areas where sound may travel over natural ground, in most situations the sound paths between roadways and NSRs lie over water and/or, due to the steep terrain, well above the ground.  In these cases a hard ground assumption is appropriate.  All natural or man-made features that could potentially provide noise screening or reflection have been accounted for in the HFANoise models. 

4.4.49    All road traffic noise levels presented in this Report are expressed in L₁₀,_{peak hour} dB(A) and have been predicted at both representative and worst-case receiving levels (elevations) at the identified assessment points.

4.4.50    Future traffic noise levels predicted at representative floor heights (low, medium and high levels for highrise buildings) of each assessment point were compared with the relevant EIAO-TM criteria, as listed in Section 4.2.4.  All criteria exceedances are considered to constitute a noise impact and therefore the use of direct mitigation measures has been investigated.  In case where direct noise mitigation measures were found to be either ineffective or unfeasible, indirect technical remedies (ITR) have been considered.

4.4.51    The predicted noise levels at each assessment points are presented in Table C8.1 in Annex C8.  A sample output of HFANoise model is provided in Annex C9.

4.4.52    Road traffic noise assessment in this Project has not included the existing Tso Wan village houses (N5) and the planning residential developments in Tai Ho (N8 to N10).  Traffic noise impact on N5 has been assessed in the R10-NLYLH EIA and the results have been summarised in this report.  N8 to N10 are outside the Project boundary and hence their road traffic noise impact will not be assessed in this Study.

Helicopter and Aircraft Noise

Helicopter Noise

4.4.53    The Government Flying Service’s helicopter fleet currently includes Sikorsky S76s and S70s.  The EIA Study Team has been provided with noise level data for these helicopters as originally supplied by the manufacturer.  While the helicopter fleet is soon to be replaced, the new models are expected to be quieter that the current ones.  Maximum flyover noise levels, at an elevation of 500 ft (152 m) above ground, were formally provided for the S76 only.  These varied marginally from 83 dB(A) at locations directly beneath the helicopter flight path to  81.5 to  82  dB(A) at sideline locations (152 m to left and right of the flight path).  Flyover noise levels from the S70s were reported to be 2 to 3 dB(A)  higher than from the S76s.  In line with the approach and parameters of the Heliport Noise Model (HNM) published by the United States Federal Aviation Administration (FAA) while predicting maximum helicopter noise levels at the proposed residential site at Siu Ho Wan and the village expansion area at Tso Wan, worst case levels of 86 dB(A) directly beneath the flight path, and 85 dB(A) at 152 m to the side of the flight path (total distance of 215 m from helicopter to ground receiver position) have been adopted.

4.4.54    In extrapolating these maximum helicopter reference noise levels to any noise sensitive locations (e.g. the proposed residential site at Siu Ho Wan and the village expansion area at Tso Wan), only the geometric (spherical) spreading of the sound waves has been assumed.  That is, atmospheric absorption has been conservatively neglected. Sample calculation for the predicted helicopter noise level are provided in Annex C9.

Aircraft Noise

4.4.55    Fixed-wing aircraft noise exposures in the vicinity of the Hong Kong International Airport are provided by the Civil Aviation Department (CAD)  in the form of Noise Exposure Forecast (NEF) contours.  The CAD’s most recent NEF projections are for the year 2030.  Assessing the compliance of aircraft noise at noise-sensitive land uses proposed under the Project with the EIAO-TM planning criteria shown in Table 4.2f is then a matter of simply overlaying the projected NEF contours onto a plan of the Study Area to determine whether the noise-sensitive land uses fall inside or outside the NEF 25 contour.

4.4.56    The typical maximum noise levels created at noise sensitive locations by normal aircraft operations will be estimated based on known measured L_max values at selected locations and extrapolated accordingly. 

4.5              NLDFS : Identification and Assessment of Environmental Impacts

Construction Phase

Potential Impacts from Project Construction Noise

4.5.1        The potential source of noise during construction phase is the use of PME on site/at shoreline for each activity during different periods of time. 

4.5.2        Broadly speaking, construction works involved in the Project are to be carried out at a few major works areas and these include:

·                      the Siu Ho Wan reclamation area for the residential and educational institutions developments;

·                      the Northshore reclamation area for the developments of the Theme Park Gateway, the Tourist & Convention Village and the Technodrome;

·                      the Eastern reclamation area at Tsing Chau Tsai for proposed recreational development;

·                      the Penny’s Bay reclamation area for the Theme Park (Phase I and II) and its associated developments, including the water recreational centre and the lake;

·                      the Theme Park Phase III Extension Area;

·                      the area for the construction of transport infrastructure within the Study Area including CKWLR, Road P1, Road P2 and other access roads; and

·                      the area for the construction of the PBRL.

4.5.3        Construction works have been divided into three phases and each phase comprises of construction activities mainly related to the following:

·                      reclamation and excavation;

·                      transport infrastructure;

·                      services infrastructure;

·                      GIC sites development;

·                      Theme Park (Phase I and II) development;

·                      Theme Park Phase III Extension development; and

·                      residential/educational/tourism/recreational developments.

 

4.5.4        While the CKWLR, proposed Road P1, the PBRL and the Theme Park (Phase I and II) and its associated developments are all under separate EIA studies, concurrent activities for the construction of the above are also accounted for to assess the cumulative construction noise impacts.  As the EIA study for the proposed CKWLR is to be covered in this EIA Report, the potential noise impact associated with the construction of the CKWLR is addressed separately in Section 4.7. 

4.5.5        As addressed in Section 4.4.1, it is assumed that construction activities of the Project, in general, will be carried out on a 16-hour day (i.e. 0700-2300) and 24 working days per month basis.  There will be an exception to some of the dredging plant used during the reclamation stage for Theme Park Phase I development, namely TS dredger, CS dredger and grab dredger, whereby they will be operating on a 24-hour day and 7 days per week basis.  Hence assessment of construction noise impacts at each NSR has been conducted to compare the results against the corresponding criteria under the different time periods.

Construction Works during Daytime and Evening Period (0700-2300)

4.5.6        The unmitigated noise levels at each NSR for each construction activity and the cumulative noise levels have been predicted.  The results are given in Annex C3a, Tables C3a.1 - C3a.7.  The predicted noise levels solely from the construction of the CKWLR and the overall cumulative noise levels have been presented in separate rows in the calculation spreadsheets.  Figures 4.3b to 4.3h show the location of noise assessment points during the construction phase.  The assessment points have been chosen to represent the worst affected NSR.  The range of noise levels predicted at each NSR is presented in Table 4.5a below.

Table 4.5a         Unmitigated Predicted Construction Noise Levels

NSR	Range of  PNL1, dB(A)2	Criteria		Critical activity causing exceedance3
		Daytime	Evening
N1-a (Peng Chau)	27-63	75	60	Reclamation and excavation works for Theme Park Development Phase I (A) + Theme Park Development Phase I (E)
N2-a (Discovery Bay)	32-64	75	60	Reclamation and excavation works for Theme Park Development Phase I (A) + Theme Park Development Phase I (E)
N3-a (Luk Keng Tsuen)	47-79	75	65	Reclamation and excavation works for Northshore (F) + Northshore Development (L) + Transport infrastructures for Northshore Reclamation  (G) + services infrastructures (H)
N5-a (Tso Wan)	56-79	75	60	Reclamation and excavation works for Fa Peng (F) + Transport infrastructures for Eastern Reclamation (G)
N8-a (Planning Area 38)	55-71	75	70	Reclamation and excavation works for Siu Ho Wan (F) causing exceedance during evening
N9-a (Planning Area 10)	68-82	75	70	Reclamation and excavation works for Siu Ho Wan (F) + Siu Ho Wan Housing Development (K) + construction of transport and services infrastructure (G+H)
N10-a (Planning Area 56)	60-75	70 during normal period/65 during examinations	N/A	Reclamation and excavation works for Siu Ho Wan (F) + Housing Foundations for Siu Ho Wan Development (K)
Note: 1.        PNL stands for Predicted Noise Level. 2.        The range of noise levels presented are the overall cumulative noise levels. 3.        Activity reference as shown in Annex C3a. 4.        TCT stands for Tsing Chau Tsai.

 

Peng Chau (N1)

 

4.5.7        As shown in Table 4.5a, no noise exceedance during daytime has been predicted at Peng Chau (N1).  However, exceedances in the range of 1-3 dB(A) have been predicted for evening time (i.e. 1900-2300).  The critical construction stage identified to be causing the noise exceedances was related to the Theme Park Phase I development.  The reclamation and excavation works for the Theme Park Phase I development (both filling and surcharge), the construction for the Theme Park building/attraction and the hotels’ superstructure were identified to be the most critical activities.

Discovery Bay (N2)

 

4.5.8        No noise exceedance during daytime has been predicted at Discovery Bay (N2).  However, exceedances in the range of 1-4 dB(A) have been predicted for evening time (i.e. 1900-2300).  Similar to Peng Chau, the critical construction stage identified to be causing the noise exceedances was related to the Theme Park Phase I development.  The reclamation and excavation works for the Theme Park Phase I development (both filling and surcharge), the construction for the Theme Park building/attraction and the hotels’ superstructure were identified to be the most critical activities.

Luk Keng Tsuen (N3)

 

4.5.9        For Luk Keng Tsuen (N3), noise exceedances in the range of 1-4 dB(A) were predicted for daytime while a maximum of 14 dB(A) noise exceedance for evening time was predicted. 

4.5.10    From the assessment results, (details as shown in Annex C3a), noise exceedances were due to cumulative impacts from construction works related to the Northshore Development (including reclamation and excavation works) and associated transport and services infrastructures.

Tso Wan (N5)

 

4.5.11    For Tso Wan (N5), noise exceedances in the range of 1-4 dB(A) were predicted for daytime while a maximum of 19 dB(A) noise exceedance for evening time was predicted. 

4.5.12    Reclamation and excavation works for Tsing Chau Tsai East together with construction works associated with transport infrastructure for Eastern Reclamation were identified to be the crucial activities causing noise exceedances. 

Planning Area 38 in Tai Ho (N8)

 

4.5.13    No noise exceedance during daytime has been predicted at the proposed residential site in Tai Ho (Planning Area 38) (N8).  However, exceedance of 1 dB(A) has been predicted for evening time (i.e. 1900-2300).  Reclamation and excavation works for Siu Ho Wan were identified to be the most critical activities causing evening time exceedance.

Planning Area 10 above Siu Ho Wan MTRC Depot (N9)

 

4.5.14    For the residential development above Siu Ho Wan MTRC Depot (N9), noise exceedances in the range of 1-7 dB(A) were predicted for daytime while a maximum of 12 dB(A) noise exceedance for evening time was predicted. 

4.5.15    Individual construction activities did not give rise to daytime noise exceedance but contributed to evening time noise exceedance.  The noise exceedances were mainly due to the cumulative noise impacts from the reclamation and excavation works for Siu Ho Wan, the foundation works for Siu Ho Wan development and the works associated with services infrastructures.  

4.5.16    Individual construction activities related to the reclamation and excavation works for Siu Ho Wan development (dredging, filling and surcharge) and the foundation works for Siu Ho Wan development themselves have exceeded the evening 70 dB(A) criterion.  Mitigation measures would therefore be required to reduce the noise impacts arising from these construction activities.

Planning Area 56 north of Siu Ho Wan (N10)

 

4.5.17    For the educational institution located to the north of Siu Ho Wan (N10), noise exceedances in the range of 1-5 dB(A) were predicted for normal periods.  As the EIAO-TM specifies a more stringent noise standards for schools during examination periods, a maximum exceedance of 10 dB(A) was predicted during the examination period.  Since  evening schooling is not expected and therefore construction noise impacts from evening works on the educational institution (N10) is not anticipated.

4.5.18    Noise exceedances were mainly due to the cumulative noise impacts from the reclamation and excavation works for Siu Ho Wan and the foundation works for Siu Ho Wan development.  Filling works for Siu Ho Wan itself has resulted in a noise level of 72 dB(A) at N10, causing a noise exceedance of 2 dB(A) for evening time.

4.5.19    Judging from the large number of construction activities and construction equipment involved in the Project, it is natural to expect that there will be certain noise impacts associated with the works.  Effective mitigation measures and proper environmental control practice should be adopted in order to reduce the noise impacts from the works.  Mitigation measures proposed to reduce the identified noise impacts during daytime and evening time are discussed in Section 4.6.1. 

Construction Works During Night-time (2300-0700)

4.5.20    As mentioned in the beginning of this sub-section, the TS dredger, the CS dredger and the grab dredger will be operating on a 24-hour day and 7 days per week basis during the reclamation stage for Theme Park Phase I development.  The construction activities involved include dredging and filling at Theme Park Phase I.  The plant inventory specifically proposed for night-time activities and the associated SWLs are given in Annex C4, Table C4.1.

4.5.21    The predicted night-time noise levels at Peng Chau (N1) and Discovery Bay (N2) are presented in Annex C4, Table C4.2.  Considering all the night-time construction activities are concentrated at Penny’s Bay and there is no line of sight from other NSRs to these construction activities, other NSRs have been excluded from the night-time construction noise assessment.  The range of unmitigated noise levels predicted at Peng Chau (N1) and Discovery Bay (N2) is presented in Table 4.5b below.

Table 4.5b         Unmitigated Predicted Night-time Construction Noise Levels

NSR	Range of PNL1, dB(A)2	Night-time criterion	Critical Activity causing exceedance
N1 - Peng Chau	37-43	45	-
N2 - Discovery Bay	39-45	45	-
Note: 1.        PNL stands for Predicted Noise Level. 2.        The noise levels presented are the cumulative noise levels.

 

4.5.22    As shown in Table 4.5b, no noise exceedance for night-time works were predicted at either Peng Chau (N1) or Discovery Bay (N2) from both individual and cumulative activities.  No adverse noise impact from night-time construction works is anticipated.

4.5.23    It should be noted that regardless of the preceding results of the construction noise impact assessment for restricted hours, i.e. evening time and night-time, the Noise Control Authority will process any CNP application, once filed, based on the NCO and the relevant technical memoranda while considering the then contemporary conditions/situations.

Operational Phase

Potential Impacts from Railway Noise

4.5.24    Table 4.5c presents the predicted facade railway noise levels at the identified NSRs.  With reference to PBRL EIA Study, a cumulative L_Aeq,30min level of 55 dB has been predicted for the nearest NSR at Luk Keng Tsuen, taking account of the noise from AEL, TCL and PBRL.  The calculated L_Amax level at Luk Keng Tsuen is 72 dB.  Noise from the operational trains of AEL and TCL would be predominant at Luk Keng Tsuen.  All the predicted values comply with the NCO and EIAO-TM noise limit and adverse noise impact at Luk Keng Tsuen is not expected.

Table 4.5c         Predicted Facade Railway Noise Levels

NSR	Distance from LAR (m)	LAeq,30min (dB)	LAmax (dB)	Remark
·       Luk Keng Tsuen  (N3-d)	385	55	72	·       Night-time noise limits of        LAeq, 30min 55 dB (Area Sensitivity Rating of “B”) and LAmax 85 dB. ·       Cumulative noise level from PBRL, AEL and TCL is presented.
·       Residential Development in Area 4A (N7-36)	250	57	69	·       Night-time noise limits of        LAeq, 30min 60 dB (Area Sensitivity Rating of “C”) and LAmax 85 dB. ·       Noise screening from the MTRC Siu Ho Wan Depot Property Development was assumed.
·       Proposed Secondary School in Area 4C (N7-55)	350	54	65	·       School is daytime sensitive only, with noise limit of        LAeq, 30min 70 dB (Area Sensitivity Rating of “C”). ·       Noise screening from the Property Development to the south of the planned secondary school was assumed.

Note:Noise levels are predicted at the first receiver floor of NSRs.

 

4.5.25    Regarding the planned uses in Areas 4A to 4C, noise predictions have been undertaken based on the methodology presented in Section 4.4.2 and assumed that the Comprehensive Development Area in the immediate south of the planning areas was in place before the development in Areas 4A to 4C.  The predicted railway noise level (L_Aeq,30min level) at the residential development in Area 4A is 57 dB, with a L_Amax level of 69 dB.  An L_Aeq,30min level of 54 dB has been predicted at the proposed secondary school in Area 4C.  All the predicted noise levels for the planned uses comply with the NCO as well as the EIAO-TM railway noise criteria. 

4.5.26    The results in Table 4.5c show that all the predicted noise levels at existing and planned NSRs will comply with the statutory requirements of the NCO and EIAO-TM.  Adverse noise impacts from operational trains are not expected and no specific noise mitigation measures are required.

4.5.27    Predicted L_{eq, 30 min} level at the Proposed Country Park Extension Area from the operation of the PBRL is in the range of 49-56 dB(A), with L_max level ranges between 57-65 dB(A).

4.5.28    In addition, there may be possible extension of the PBRL to the eastern reclamation area and to HK Island in future.  As no NSRs are located in the vicinity of these possible extensions, it is expected that the associated noise impact would be minimal.

Potential Impacts from Fixed Plant Noise

4.5.29    The potential fixed plant sources considered in this Project include Theme Park (Phase I and II) operation, Theme Park (Phase III) Extension, fireworks displays, the recreational development at Tsing Chau Tsai East, Penny’s Bay GTP, Penny’s Bay Sewage Pumping Station, Siu Ho Wan Water and Sewage Treatment Works and North Lantau Transfer Station, the fixed plant of PBRL, vehicles parking areas and PTIs at Yam O and Penny’s Bay.  However, not all the NSRs are affected by all these noise sources due to substantial terrain screening and large separation distances between these sources and certain NSRs, and thus minimal impacts are anticipated in many cases.  The potential impacts of the noise sources assessed at each NSR are shown in Table 4.5d below.

Table 4.5d         Potential Fixed Plant Noise Sources Assessed for Each NSR

NSR	Fixed Plant Noise Sources
N1 - Peng Chau	·       Theme Park (Phase I and II) Operation ·       Theme Park (Phase III) Extension ·       Fireworks Displays ·       Penny’s Bay GTP ·       Sewage Pumping Station ·       PBRL ·       PTI at Penny’s Bay ·       vehicles parking areas
N2 - Discovery Bay	·       Theme Park (Phase I and II) Operation ·       Theme Park (Phase III) Extension ·       Fireworks Displays ·       Penny’s Bay GTP ·       Sewage Pumping Station ·       PBRL ·       PTI at Penny’s Bay ·       vehicles parking areas
N3 - Luk Keng Tsuen	·       PBRL ·       PTI at Yam O
N4 - Lantau North Country Park	Nil
N4’ - Proposed Country Park Extension Area	·       Theme Park (Phase I and II) Operation ·       Theme Park (Phase III) Extension ·       Fireworks Displays ·       Penny’s Bay GTP ·       Sewage Pumping Station ·       PBRL ·       PTI at Penny Bay
N5 - Tso Wan	·       Recreational development at Tsing Chau Tsai East
N6 - Tso Wan Village Expansion Area	·       Recreational development at Tsing Chau Tsai East
N7 - Planning Area 4A to 4C in Siu Ho Wan	·       Sewage and Water Treatment Works ·       North Lantau Transfer Station
N8 - Planning Area 38 in Tai Ho	Nil
N9 - Planning Area 10 at Siu Ho Wan MTRC Depot	Nil
N10 - Planning Area 56 in Tai Ho	Nil

 

Theme Park (Phase I - II) Operation

4.5.30    The Theme Park (Phase I and II) operation noise levels at residential NSRs at Peng Chau and Discovery Bay and at points within the Proposed Country Park Extension Area have been estimated as described in Section 4.4.3. 

4.5.31    The results of these noise predictions are summarised in Table 4.5e below.

Table 4.5e    Potential Noise Impacts of Theme Park Operations (Phases I and           II)

Noise Impact Assessment Location	Theme Park Noise Levels (LAeq, 30min dB)			EIAO-TM Noise Criteria (LAeq, 30min dB)
	Phase I	Phase II	Total	Day/Evening (0700 to 2300)	Night-time (2300 to 0700)
N1-a  Peng Chau	42	40	44	50	45
N2-a Discovery Bay	43	39	44	50	45
Proposed Country Park Extension (N4’-c)	62	55	62	N/A	N/A
Proposed Country Park Extension (N4-d)	67	57	67	N/A	N/A

Note:   In predicting Theme Park noise levels at NSRs and the Proposed Country Park Extension Area, atmospheric absorption was accounted for, as were earth berm/hotel shielding and facade hillside reflection, as appropriate.  

 

4.5.32    It is seen from Table 4.5e that the total projected Phase I and Phase II Theme Park operation noise levels at both Peng Chau and Discovery Bay  are L_Aeq,30min 44 dB.  These noise levels then comply with the daytime/evening fixed plant planning limit of L_Aeq,30min 50 dB (established in Section 4.3.3) as well as the night-time limit of L_Aeq,30min 45 dB.

4.5.33    For general information it may be useful not just to examine the statutory L_eq values but also look at the L_max levels.  Based on the measured L_max levels as provided by HKITP on various rides and attractions of the Anaheim, California facilities, it has been predicted that the L_max level as perceived at Peng Chau will be around 60 dB(A).  A similar L_max level is also anticipated at Discovery Bay due to the noisiest rides.

Theme Park (Phase III) Extension Operation

4.5.34    As indicated in Table 4.5e above, there is a safety margin of 6 dB(A) both for Peng Chau and Discovery Bay before exceeding the daytime and evening 50 dB(A) criterion. 

4.5.35    By assuming that the Theme Park (Phase III) Extension would have a L_eq level of 75 dB(A) at the perimeter, it will then generate an operational SWL similar to that of Theme Park Phase I or Phase II operation, a worst case of an extra 3 dB(A) addition would apply to the noise levels perceived at Peng Chau and Discovery Bay.  The resulting 47 dB(A) noise level would still comply with the daytime and evening 50 dB(A) criterion.

4.5.36    As pointed out in Section 4.4.3, Theme Park (Phase III) Extension will not operate beyond 2300 hours, noise impact during night-time could thus be completely eliminated.

4.5.37    Theme Park (Phase III) Extension being located further away from the Proposed Country Park Extension Area, with a separation distance of more than 2.2 km, it is expected that noise levels perceived at the Proposed Country Park Extension Area from the operation of Theme Park (Phase III) Extension are insignificant.

Fireworks Displays

4.5.38    Fireworks displays to be presented at the Theme Park Phase I and Phase II area have not yet been developed in any detail.  However, the EIA Study Team has obtained, during a specially-staged demonstration, representative source noise data covering the range of fireworks types that could be considered for use in Hong Kong.

4.5.39    The relevant individual source noise data obtained were used to compute the resultant noise picture of a 5 minute mid-level (approximately 100 m in height) fireworks show (see Annex C7).  It has been demonstrated that the L_{Aeq, 15min} 55 dB limit could be met while taking a good mixture of various fireworks items considered appropriate for the Hong Kong situation.

4.5.40    In the absence of even preliminary designs of the fireworks displays at this stage, the EIA Study Team has demonstrated and illustrated one possible scenario.  In the process of deriving the detailed design of the fireworks show, it would be necessary to ensure the noise emission from the actual show would correspond and not exceed those contained in this assessment.

4.5.41    For information, to supplement the equivalent noise level, it is also anticipated that maximum levels of approximately 85 dB(A) would be perceived at relevant NSRs in Peng Chau and Discovery Bay.  Such maximum levels are from the effects related to individual fireworks items.

4.5.42    Fireworks displays will only occur after dark, and since the Proposed Country Park Extension Area adjacent to Penny’s Bay would not normally be expected to have visitors after dark, there would be no potential for fireworks noise impact at this location.  There would, therefore, appear to be no need to establish a fireworks noise criterion or limit for this area.

Recreational development at Tsing Chau Tsai East

4.5.43    Recreational activities at the Tsing Chau Tsai East development area is a potential noise source causing impact to nearby NSRs, in particularly, Tso Wan (N5) and the Tso Wan Village Expansion Area (N6).  With the operation of Route 10 - NLYLH in the future, road traffic noise will become the dominant source impacting on Tso Wan area.  Moreover, though intended to mitigate road traffic noise, the 3-8 m high vertical and cantilever barriers proposed on the western side of the Route 10 alignment (northbound direction), will act to shield some of the operational noise from the Tsing Chau Tsai East recreational area.

Penny’s Bay GTP

4.5.44    The distance from the Penny’s Bay GTP to the nearest point within the hotel zone is approximately 1300 m.  Based on the reference source level of 75 dB(A) at the site boundary (see Section  4.4.3), the essentially steady power plant noise levels at the closest point within the Theme Park (Phase I and II) hotel zone is projected to be approximately 55 dB(A).  This noise level is for reference only as the hotels would not rely upon openable windows for ventilation and consequently the impact on the guests therein would be minimal.

4.5.45    In calculating these noise levels, a +3 dB(A) facade reflection correction was applied at the hotel location.  While no screening factors were included in the above predictions, it is expected that noise levels will be further reduced due to the screening provided by the 9 m earth berm and by structures within the Theme Park (Phase I and II) itself.  Further, as rooms of the hotels will not rely on openable windows for ventilation, noise impacts from the GTP will not provide any noise constraint at this location. 

4.5.46    The distance form the Penny’s Bay GTP to the nearest point at the boundary of the Proposed Country Park Extension Area (N4’-c) is about 860 m.  The power plant noise level predicted at this point is approximately 59 dB(A).

(Utility Yard) Sewage Pumping Station

4.5.47    From Utility Yard, given the relatively large distances (2.8 to 3.2 km) to the NSRs in the present case, sewage pumping noise levels will not then even approach the EIAO-TM limits.  Further, the Theme Park visitors will be effectively shielded from any sewage pumping station noise by the 9 m earth berm.  In addition, noise emitted from the pumping facilities could further be minimised by incorporating acoustic design, such as installing silencers to the intake and exhaust air openings.

4.5.48    The separation distance between the proposed sewage pumping station and the Proposed Country Park Extension Area is about 780 m.  This separation distance will itself provide more than 50 dB(A) distance attenuation on the noise emitted from the sewage pumping station.

Sewage and Water Treatment Works

4.5.49    Sewage and Water Treatment Works located to the west of Planning Areas 4A to 4C in Siu Ho Wan (N7) is a potential noise source to the proposed residential and institutional developments in the Draft RODP (Planning Areas 4A to 4C).

4.5.50    However, noise generated from these fixed plant sources can be shielded by the residential towers on the MTRC Depot development, which are to be built before the proposed Siu Ho Wan development.  Thus, noise impacts from these fixed plants on the Siu Ho Wan development can be reduced.  Further, with the operation of Road P1 in the future, road traffic noise will become the dominant source in the environment.

North Lantau Refuse Transfer Station (NLRTS)

4.5.51    The existing North Lantau Transfer Station is located to the northeast of Planning Areas 4A to 4C in Siu Ho Wan (N7).  As most of the activities are enclosed within the transfer building and given its large distance away from NSR N7, it is envisaged that noise impact from the refuse transfer station would be minimal.

4.5.52    Given most of the activities are enclosed within the transfer building, noise impact from the NLRTS to the Proposed Country Park Extension Area would also be minimal.

Fixed plant of Penny’s Bay Rail Link

4.5.53    Sources of fixed plant noise for the Proposed PBRL include:

·                      transformers and substations for power supply to the railway;

·                      ventilation buildings located at the northern and southern tunnel portal for tunnel ventilation; and

·                     washing facilities located close to the Penny’s Bay Rail Station.

 

4.5.54    These required plant and tunnel ventilation equipment will be designed by the PBRL operator, MTRC, to ensure that the noise levels at any NSR will be 5 dB lower than the NCO criteria as mentioned in Section 4.2.3.  Given the large distance separation between the alignment and the NSRs, and the provision of 9 m earth berm next to the proposed railway, this will be easily achieved by adoption of good engineering practice.

Public Transport Interchanges (PTIs)

4.5.55    The effective SWLs measured by the EIA Study Team at some of the larger PTIs in Hong Kong (e.g. Kwun Tong and Shing Tak Centre) during the morning peak, afternoon peak and evening were L_Aeq 110, 109 and 105 dB(A) respectively[8].  Using these measured SWLs, PTI noise levels have been projected at four NSRs: at Peng Chau and Discovery Bay and the Proposed Country Park Extension Area (potentially affected by Penny’s Bay PTI) and at Luk Keng Tsuen (potentially affected by Yam O PTI).  The predicted noise levels at these NSRs are shown in Table 4.5f. 

4.5.56    When assessing the PTIs, these projections have included a - 5 dB(A) screening factor for the noise shielding which will be provided by the Theme Park (Phase I and II) buildings, earth berms and hotels to be located between the Penny’s Bay PTI and Peng Chau or Discovery Bay, and also the noise shielding provided by the Theme Park Gateway located between the Yam O PTI and Luk Keng Tsuen. A +3 dB(A) factor has been applied for building facade reflections.  Owing to elevated location of the Proposed Country Park Extension Area , no such shielding factors were applied in this case.  Atmospheric absorption was conservatively neglected.

4.5.57    The results of Table 4.5f show that the noise from the closest PTI will be far below the appropriate reference criteria at all the three residential NSRs.

Table 4.5f - Projected Noise Impacts from Operation of Penny's Bay and Yam O PTIs

Time Period	Predicted Noise Levels (1) (LAeq, 30min dB)				Noise Criterion (2)
	Peng Chau N1-a	Discovery Bay N2-a	Luk Keng Tsuen N3-d	Proposed Country Park Extension N4’-c	NSR’s Only
AM Peak	30	30	37	43	50/60
PM Peak	29	29	36	42	50/60
Evening	25	25	32	38	50/60

Note:

(1)  A shielding factor of -5 dB(A) was applied to the PTI noise levels as projected at Peng Chau and Discovery Bay.  However, atmospheric absorption was conservatively neglected.

(2)  The criterion of 50 dB(A) is used for Peng Chau and Discovery Bay while 60 dB(A) is used for Luk Keng Tsuen.  There is no specific criteria for country park.

 

Vehicle Parking Areas

4.5.58    Two vehicle parking areas are to be located immediately north of the Theme Park and the PBRL at Penny’s Bay.  However, because of the relatively low speeds at which vehicles are required to travel in such facilities, the vehicle parking areas are not considered to represent significant sources of Project operational noise when compared, for example, with the access roads leading to and from these parking lots and the hotel areas (Roads P1, P2, D1 and D2).

Future Container Terminal Development

4.5.59    As the hotels at the Theme Park (Phase I and II) will not rely on openable windows for ventilation, potential noise impacts from the operation of the future Container Terminal development south of the area on the hotels will be minimal.

Potential Fixed Plant Noise from Proposed Ventilation Building

4.5.60    Fixed plant noise from the ventilation building proposed at Yam Tsai Tunnel may impact upon nearby NSRs, namely Luk Keng Tsuen (N3).  However, with a separation distance of more than 400 m from the tunnel and the screening effect provided by the terrain therein, it is anticipated that noise impact from the ventilation facilities would be minimal.

Water Recreation Centre (WRC)

4.5.61    The proposed WRC will include a boating facility, changing rooms, restaurants and canteens, etc.  Secondary uses may include storage, kitchens and food preparation areas, etc.  In view of the proposed uses of the WRC, it is expected that noise emitted from its operation would be minimal.

Cumulative Noise Levels from all Fixed Plant Sources

4.5.62    Theoretically the noise contributions from all fixed plant sources in the Study Area could be summed and the cumulative impacts assessed at sensitive locations.  However, as most of these sources will be located north of the Theme Park Phase I and II (and thereby shielded by the boundary earth berm and buildings within the Theme Park Phase I and II) and they are of much smaller scale (both physically and relative to acoustical intensity), their contributions to the overall resultant noise climate will be minimal as compared to the operational noise of the Theme Park Phase I and II and its associated developments.

4.5.63    To illustrate this effect, the approximate 3 km separation between the GTP and Peng Chau would render the occasional operational noise from the GTP inaudible at the NSR.

4.5.64    Other fixed plant sources are located in discrete area in the Draft RODP and given their large distances away from the NSRs, they should not pose cumulative impacts to the NSRs.

Road Traffic Noise

4.5.65    Road traffic noise modelling has been undertaken at representative NSRs and the prediction results are given in Table C8a in Annex C8.

4.5.66    The only existing NSR assessed in this Project is Luk Keng Tsuen (N3).  Road traffic noise impact on existing village houses in Tso Wan (N5) has already been assessed in the Route 10 EIA Report, as mentioned in Section 4.3.1 and the results have been summarised in this Report.

4.5.67    For Peng Chau (N1), Discovery Bay (N2), and the existing Lantau North Country Park (N4), traffic noise was not assessed as no impacts were anticipated due to large separation distances (e.g. around 2.2 km between Road D1 and Discovery Bay and around 7 km between the nearest Country Park boundary and the Project boundary) and the very substantial terrain screening the proposed road network from the sensitive receivers.

4.5.68    For the proposed Tso Wan Village Expansion Area (N6), three representative assessment points (N6-a to N6-c) were identified.  The worst case road traffic scenario adopted and the proposed mitigation measures in the Route 10 EIA Report (including 3-8 m vertical and cantilever barriers along the western side of the Route 10 alignment (northbound direction) was used in predicting noise levels at this NSR.  The predicted noise levels at these assessment points are well within the EIAO-TM criterion.  The road traffic modelling results are presented in Annex C8, Table C8.1.

4.5.69    Road traffic noise levels have also been predicted at Planning Area 4A to 4C in Siu Ho Wan.  Thirty-nine assessment points (N7-1 to N7-39) representing the worst residential facades affected by road traffic noise were selected for assessment.  Representative assessment points were also identified for the proposed Primary School (N7-50 to N7-54) and Secondary School (N7-53 to N7-56) at the junction of Road P1 and the Access Road to the Siu Ho Wan Development.   For other planned development in Tai Ho (N8 to N10), traffic noise impact was assessed in a separate EIA study and therefore they would not be included in the traffic noise assessment of this Project.

4.5.70    The results of the traffic noise modelling are discussed in the following paragraphs.

Luk Keng Tsuen (N3-b to N3-d)

4.5.71    The noise levels predicted at these assessment points were contributed by Road P1 and its associated slip roads (new roads) and the existing North Lantau Highway (unaltered road).  The results of the modelling indicate that if traffic noise on Road P1 and the associated slip roads remain unmitigated, noise criterion exceedances of 1 dB(A) at all three residential dwellings are likely.  Direct mitigation measures will therefore be assessed to alleviate the noise impact from Road P1 and the slip roads.

Planning Area 4A & 4B (N7-1 to N7-39)

4.5.72    Results of the modelling indicated that if traffic noise on Road P1 remain unmitigated, criterion exceedances of up to 6 dB(A) affecting approximately 1120 residential dwellings are likely.  Road P1 was identified as the dominant noise source to the proposed development and therefore, direct mitigation measures will therefore be assessed to alleviate the noise impact from Road P1.

Planning Area 4C (N7-50 to N7-56)

4.5.73    Results of the modelling indicated that if traffic noise on Road P1 remain unmitigated, criterion exceedances of up to 12 dB(A) affecting approximately 67 classrooms are likely.  Road P1 was identified as the dominant noise source to the proposed development and therefore, direct mitigation measures will therefore be assessed to alleviate the noise impact from Road P1.

Proposed Country Park Extension Area (N4’)

4.5.74    Traffic noise levels have been calculated at three assessment points at the Proposed Country Park Extension Area, mainly located to the west of Penny’s Bay.  For the existing Lantau Country Park, traffic noise was not assessed as no impact was anticipated due to large separation distance and the very substantial terrain screening the proposed road network from this sensitive land use.

4.5.75    The noise level predicted at the Proposed Country Park Extension Area at each assessment point is presented in Table 4.5g.

Table 4.5g - Predicted Road Traffic Noise Levels

Assessment Points	Predicted Noise Levels (L10 dB(A))
N4’-b	70
N4’-c	67
N4’-d	40

 

4.5.76    Table 4.5g shows that the predicted road traffic noise levels along the boundary of the Proposed Country Park Extension Area fall within the range of 40 dB(A) to 70 dB(A).

4.5.77    Road traffic noise from the existing NLH is the dominant source impacting on the northern side of the Proposed Country Park Extension Area facing Siu Ho Wan area.  With the operation of Road P1 in the future, it is envisaged that road traffic noise levels at the Proposed Country Park Extension Area will not increase significantly as the road alignment runs in general at a separation distance of at least 300 m from the northern boundary of the Proposed Country Park Extension Area.

Tso Wan (N5)

 

4.5.78    Based on the Route 10 EIA Report, mitigated road traffic noise levels at Tso Wan village (22 assessment points representing 24 dwellings) were predicted to be in the range of 55 - 70 dB(A).  Results indicated that with the proposed mitigation measures in place, road traffic noise levels at the existing Tso Wan village would comply with the 70 dB(A) EIAM-TM criterion.

Tso Wan Village Expansion Area (N6)

      

4.5.79    Road Traffic noise levels predicted at the three assessment points at Tso Wan Village Expansion Area (N6-a to N6-c) were 54 dB(A) taking into consideration mitigation measures proposed in the Route 10 EIA.  The results indicated that road traffic noise impact at these NSRs is well within the EIAO-TM criterion.             

Helicopter Noise

4.5.80    The emergency flight path followed by helicopters in travelling between Hong Kong International Airport and Hong Kong Island is shown in Figure 4.1a .  It is seen that the flight path passes to the north of Planning Areas 4A to 4C in Siu Ho Wan (N7) and north of the Phase II Theme Park area so that the nearest identifiable noise sensitive land use to the flight path will be NSR 7 and the hotels to be built directly south of the Theme Park Phase I and II area.  Such hotels, however, will not rely on openable windows for ventilation, and the potential for helicopter noise impacts would be minimal.

4.5.81    Helicopter noise at NSR N7 has been estimated for indication purposes.  They are shown in Figure 4.5a.

4.5.82    The predicted maximum helicopter noise level exceeded the residences criterion of L_Amax 85 dB by 1 dB.  However, as this helicopter flight path is an emergency path to be used only in adverse weather, it is anticipated that the noise impact to NSR N7 would be minimal.

4.5.83    As for Tso Wan Village Extension Area (N6), helicopter noise is unlikely to be audible there, since NSR N6 will be located at more than 1 km from the nearest helicopter path and it is screened by at least two layers of terrain features.

Aircraft Noise

4.5.84    Figure 4.1a shows that the NEF 25 contour, projected for the year 2030, does not approach any part of the NSRs considered in this Project.  There will therefore be no noise impacts from fixed-wing aircraft on all the NSRs.

4.5.85    Additionally, for general indication purposes, typical L_max values at the Planning Areas 4A to 4C in Siu Ho Wan and Tso Wan have been estimated.  They are generally at 75 dB(A) and are shown in Figure 4.5a.

4.6              NLDFS: Mitigation of Adverse Environmental Impacts  

Mitigation of Adverse Construction Noise Impact

4.6.1        Noise emissions from construction activities can be minimised through good site practice, selecting quiet plant, adopting quieter working methods, erection of noise barriers to screen the noise source, where appropriate, and posing restriction on the usage of noisy equipment.  The recommended mitigation measures detailed in this section should be incorporated into the Contract Specification in order to ensure the environmental performance of construction works.

4.6.2        Contractors may develop a different package of environmental control measures to meet the required noise standards, but the following illustrates a feasible approach to mitigate the predicted noise impact during the construction phase:

Good Site Practice

4.6.3        In view of the large number of construction activities and construction equipment considered in the Project,  adverse construction noise impact without mitigation to the surrounding environment are likely.  Before going into details discussing specific mitigation measures for construction works, good site practice and proper on-site management are required by Contractors at all times in order to minimise noise emissions from the works.  The following measures are recommended:

·                      Only well-maintained plant shall be operated on-site and plant shall be serviced regularly during the construction works;

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

·                      Silencers or mufflers on construction equipment shall be utilised and be properly maintained during the construction works;

·                      Mobile plant shall be sited as far away from NSRs as possible; and

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

 

4.6.4        Although it is difficult to quantify the level of noise reduction achieved from incorporation of these elements, the environmental performance of the works would be improved with these control measures.

Selecting Quieter Plant

4.6.5        The use of quiet plant is identified to be a feasible solution to tackle the adverse impact associated with construction works.  The Contractors may be able to obtain particular models of plant that are quieter than standard types given in GW-TM.  The benefits achievable in this way will depend on the details of the Contractors’ chosen methods of working, and it is considered too restrictive to specify that a Contractor has to use specific items of plant for the construction operations.  It is therefore both preferable and practical to specify an overall plant noise performance specification to apply to 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.

4.6.6        Quiet plant is defined as PME whose actual SWL is less than the value specified in GW-TM for the same piece of equipment.  Examples of SWLs for specific silenced PME taken from a British Standard, namely Noise Control on Construction and Open Sites, BS5228: Part 1: 1997, which are known to be used are given in Table 4.6a.

Table 4.6a - Sound Power Levels for Specific Silenced PME

PME	BS5228 Table no.	Ref no.	SWL, dB(A) max
Breaker	C.2	10	110
Dozer	C.9	2	104
Mobile Crane	C.7	114	101
Concrete Pump	C.6	22	106
Dump truck	C.9	27	105
Excavator/Loader	C.3	97	105
Generator	C.7	62	100
Lorry	C.8	16	108
Concrete truck (mixer)	C.6	35	100
Grader	C.9	11	110
Road Roller	C.8	27	104
Poker Vibrator	C.6	32	100

 

4.6.7        It should be noted that various types of silenced equipment can be found in Hong Kong.  However, the EPD, when processing a CNP application, will apply the noise levels contained in the GW-TM, unless the noise emission of a particular piece of equipment can be validated.

4.6.8        The mitigated noise levels at each NSR for each construction activity and the overall cumulative noise levels have been predicted and the details are given in Annex C3b, Tables C3b.1-C3b.7.  The range of mitigated noise levels predicted with the use of quiet plant is presented in Table 4.6b below.

Table 4.6b - Mitigated Construction Noise Levels - with the use of quiet plant

NSR	Range of PNL1, dB(A)2	Criteria		Critical activity causing exceedance3
		Daytime	Evening
N1-a (Peng Chau)	27-59	75	60	-
N2-a (Discovery Bay)	29-60	75	60	-
N3-a (Luk Keng Tsuen)	40-73	75	65	Reclamation and excavation works for Northshore (F), Roadwork for Northern reclamation (G), Construction of services infrastructure (H)
N5-a (Tso Wan)	56-71	75	60	Filling reclamation for Fa Peng (F), Roadwork for Eastern reclamation (G).
N8-a (Planning Area 38)	53-66	75	70	-
N9-a (Planning Area 10)	63-76	75	70	Dredging and filling works for Siu Ho Wan (F) + Siu Ho Wan Housing Development (K)
N10-a (Planning Area 56)	54-69	70 during normal period/65 during examinations	N/A	Reclamation works for Siu Ho Wan (F)
Note: 1.        PNL stands for Predicted Noise Level. 2.        The range of noise levels presented are the overall cumulative noise levels. 3.        Activity reference as shown in Annex C3b, Table C3b.1-C3b.7. 4.        TCT stands for Tsing Chau Tsai.

 

Peng Chau (N1), Discovery Bay (N2) and Planning Area 38 in Tai Ho (N8)

 

4.6.9        As shown in Table 4.6b, with the use of quiet plant, no noise exceedance was predicted at Peng Chau (N1), Discovery Bay (N2) and the planned residential development in Tai Ho (N8 - Planning Area 38) during both daytime and evening time.  The adoption of quiet plant has reduced the predicted noise levels at these NSRs to within criteria.

Luk Keng Tsuen (N3)

 

4.6.10    With the use of quieter plant, the maximum predicted noise level was reduced from 79 dB(A) (without mitigation) to 73 dB(A).  This 6 dB(A) reduction in noise level has resulted in compliance at Luk Keng Tsuen (N3) of the 75 dB(A) daytime construction noise criterion.  However, exceedances in the range from 1 to 8 dB(A) were still predicted for evening.  Construction of services infrastructure, reclamation and excavation works for Northshore and roadwork for Northshore Reclamation were identified to be the crucial activities causing noise exceedances.

4.6.11    In order to further reduce the noise levels at Luk Keng Tsuen (N3), further noise mitigation measures, such as the erection of noise barriers, would need to be considered. 

Tso Wan (N5)

 

4.6.12    Noise levels predicted at Tso Wan (N5) were in the range of 56-71 dB(A).  With the use of quiet plant, no daytime exceedance at Tso Wan was predicted.  The  maximum 11 dB(A) exceedance for evening were mainly due to filling reclamation for Fa Peng and roadwork for Eastern Reclamation.

Planning Area 10 above Siu Ho Wan MTRC Depot (N9)

 

4.6.13    The range of noise levels predicted at the planned residential development above Siu Ho Wan MTRC Depot was 63 - 76 dB(A).  Dredging and filling works for Siu Ho Wan and construction works related to the Siu Ho Wan Housing Development were identified to be the prominent activities causing both daytime and evening exceeedances.  The recommendation of subsequent  mitigation measures would need to be considered.

Planning Area 56 north of Siu Ho Wan (N10)

 

4.6.14    The maximum noise level predicted at the planned educational institution located to the north of Siu Ho Wan was 69 dB(A).  The noise levels predicted at this site were in compliance to the 70 dB(A) criterion during normal periods.  However, with the more stringent criterion during examination periods (i.e. 65 dB(A)), noise exceedances in the range of 1-4 dB(A) were predicted.  In order to reduce the noise impact so that compliance during examination periods can also be achieved, further noise mitigation measures are to be considered.    

4.6.15    Since evening schooling is not expected, construction noise impact from evening works on the education institution (N10) is therefore not anticipated

Use of Temporary and Movable Noise Barriers 

4.6.16    In general, purpose-built noise barriers or screens constructed of appropriate material to be located close to operating PME could give a noise reduction of up to 5 dB(A) (estimated in accordance with the GW-TM).  This level of noise reduction could also be achieved by erecting temporary noise barriers along active work sites.  Certain types of PME, such as generators, can be completely screened giving a total noise reduction of 10 dB(A) or more.

4.6.17    It is anticipated that a movable noise barrier with a suitable footing and a small cantilevered upper portion can be located within a few metres of a static plant and within about 5 m of more mobile equipment such as excavator and mobile crane etc., such that the line of sight could be blocked by the barriers viewed from the NSRs.  The estimated noise reduction by means of screening, provided that the barriers are carefully located, can provide at least 10 dB(A) noise attenuation for static plant and 5 dB(A) for mobile plant.  The noise screening benefit for each plant considered in this assessment is listed below:

·                      Stationary Plant - assuming 10 dB(A) reduction: poker vibrator, concrete pump and generator; and

·                      Mobile Plant - assuming 5 dB(A) reduction: excavator, grader, road roller, mobile crane and concrete truck.

Restriction on the Usage of Operating PME

4.6.18    In some cases, the number of plant in operation may need to be controlled so as to reduce the noise emissions during critical construction stages.  In this assessment, restriction on PME usage has been tested by limiting the number of plant used for certain selected construction activities.  These include the reduction on the number of plant for the following construction activities:

·                      Filling reclamation for Northshore (Yam O Bay to To Kau Wan)

·                      Dredging for Siu Ho Wan

·                      Filling reclamation for Siu Ho Wan

·                      Surcharge placement for Siu Ho Wan

 

4.6.19    The details of the number of plant reduced are presented in Annex C2, Table C2.3.  The above construction activities have been chosen to further ameliorate the adverse noise impact predicted at Luk Keng Tsuen (N3) and the developments at Siu Ho Wan area, including the planned residential development above Siu Ho Wan MTRC Depot (N9).  The proposed restriction in the plant team number is considered to be feasible by the Design Engineer and would meet the intended Project implementation programme.

4.6.20    Table 4.6c presents the predicted noise levels at NSRs, with the use of quiet plant, the erection of noise barriers and the restriction on the number of operating PME for the aforementioned construction activities. 

Table 4.6c - Mitigated Construction Noise Levels - with the use of quiet plant, erection of barriers and restriction on PME usage

NSR	Range of PNL1, dB(A)2	Criteria		Critical activity causing exceedance3
		Daytime	Evening
N3-a (Luk Keng Tsuen)	40-70	75	65	Filling reclamation for Northshore (F), Roadwork for Northern Reclamation (G)
N5-a (Tso Wan)	50-69	75	60	Filling reclamation for Fa Peng (F)
N8-a (Planning Area 38)	52-64	75	70	-
N9-a (Planning Area 10)	63-73	75	70	Filling reclamation for Siu Ho Wan (F)
N10-a (Planning Area 56)	54-66	70 during normal periods and 65 during examination period	N/A	Reclamation works for Siu Ho Wan (F)
Note: 1.        PNL stands for Predicted Noise Level. 2.        The range of noise levels presented are the overall cumulative noise levels. 3.        Activity reference as shown in Annex C3c, Tables C3c.1-C3c.5. 4.        TCT stands for Tsing Chau Tsai.

 

Luk Keng Tsuen (N3) and Planning Area 38 in Tai Ho (N8)

4.6.21    Results in Table 4.6b indicated that with the use of quiet plant only, maximum noise levels of 73 dB(A) and 66 dB(A) were predicted at Luk Keng Tsuen (N3) and the planned residential development in Tai Ho (N8 - Planning Area 38) respectively.  With the adoption of additional mitigation measures, including the erection of noise barriers and the restriction on PME usage, an additional  2-3 dB(A) reduction in the maximum noise levels were achievable  at these NSRs.

Tso Wan (N5) and Planning Area 10 above Siu Ho Wan MTRC Depot (N9)

4.6.22    As shown in Table 4.6c, with the implementation of the above proposed mitigation measures, including the use of quiet plant, the erection of noise barriers and the restriction on operating PME usage, noise levels predicted at Tso Wan (N5) and the planned residential development above Siu Ho Wan MTRC Depot (N9) would comply with the daytime 75 dB(A) criterion. 

4.6.23    However, noise exceedances for evening works were still predicted at Luk Keng Tsuen (N3), Tso Wan (N5) and the planned residential development above Siu Ho Wan MTRC Depot (N9).

Planning Area 56 north of Siu Ho Wan (N10)

4.6.24    For the planned educational institution located to the north of Siu Ho Wan (N10), even with the implementation of all the above mitigation measures, a maximum noise level of 66 dB(A) was still predicted.  Reclamation and excavation works for Siu Ho Wan were identified to be the critical activities causing noise exceedance during examination periods.  Hence, it is recommended that re-scheduling of reclamation and excavation works for Siu Ho Wan are required so as to avoid the undertaking of these activities during examination periods.

Restriction on Evening Works

4.6.25    As noise exceedances for evening works were still predicted at Luk Keng Tsuen (N3), Tso Wan (N5) and the planned residential development above Siu Ho Wan MTRC Depot (N9), it is recommended that re-scheduling of certain construction activities to avoid evening works are required to subsequently  reduce the noise impact to comply with the criteria.

4.6.26    The construction activities considered for evening restriction include construction activities related to the reclamation and excavation works for Northshore, roadwork for Northern Reclamation and installation of services infrastructure to mitigate the noise impact at Luk Keng Tsuen (N3).  With the restriction of these activities, the noise levels predicted were in the range of 40-64 dB(A), which indicated compliance with the evening 65 dB(A) criterion.

4.6.27    All the major construction activities considered affecting Tso Wan (N5) are recommended to be restricted during evening to minimise the noise impact.

4.6.28    Based on our assessment results, reclamation and excavation works for Siu Ho Wan were identified to be the critical activities causing evening exceedance at the planned residential development above Siu Ho Wan MTRC Depot (N9).  As such, re-scheduling of the reclamation and excavation works for Siu Ho Wan to avoid evening works should be considered to lessen the noise levels.  The resultant noise levels were predicted to be in the range of 63-69 dB(A), which comply with the evening 70 dB(A) criterion.

Construction Noise Impacts at Lantau North Country Park and the Proposed Country Park Extension Area

4.6.29    The separation distance between the boundary of the existing Lantau North Country Park and the nearest construction work site associated with the Project is about 7 km.  In view of such large separation distance and the terrain screening therein, construction noise impacts from the Project, both individual and cumulative, on the existing Country Park are not expected.

4.6.30    Based on the findings from the PBRL EIA Study, noise levels from the construction of the PBRL at the Proposed Country Park Extension Area (N4’-b to N’4-d) have been predicted to be in the range of 49-64 dB(A).  With the addition of other concurrent construction activities under Theme Park and associated developments, predicted noise levels will only be slightly higher as most other construction sites are located far away from the Proposed Country Park Extension Area.

4.6.31    It is not expected that visitors will visit the Proposed Country Park Extension Area after dark, night-time construction noise impact from the Penny’s Bay dredging and filling works during Theme Park Phase I development on the Proposed Country Park Extension Area is so not anticipated.

4.6.32    As the northern boundary of the Proposed Country Park Extension Area (N4’) is located further away from the Siu Ho Wan MTRC Depot redevelopment site (N9), it is expected construction noise levels perceived at N4’ from Siu Ho Wan reclamation works will be less than that at N9.

MITIGATION OF ADVERSE OPERATIONAL NOISE IMPACT

Fixed Plant - Theme Park

4.6.33    The operational noise assessment, as discussed in the preceding section (Section 4.5), did not predict any exceedance of the relevant noise criteria due to the operation of the Theme Park and other associated developments.  Therefore, no specific  mitigation measures during operational phase are required.

4.6.34    However, for fireworks displays at Theme Park (Phase I and II), a maximum duration of 5 minutes for mid-level shows and a maximum height of 100 m are recommended.

4.6.35    For other fixed plant noise sources, such as the Penny’s Bay GTP, the proposed PTIs at Yam O and Penny’s Bay and the Sewage and Water Treatment Works at Siu Ho Wan area, etc., assessment revealed that their impacts on NSRs are minimal and are within the relevant criteria.

Road Traffic Noise

4.6.36    The assessment in Section 4.5.4 indicates that some assessment points in Luk Keng Tsuen (N3-b to N3-d) and Planning Area 4A to  4C in Siu Ho Wan (N7-1 to N7-39 and N7-50 to N7-56) will be exposed to unmitigated road traffic noise from Road P1 which exceed the EIAO-TM criteria.  Mitigation measures will be necessary to alleviate the noise impacts.  Figures 4.6a and 4.6b show the proposed mitigation measures at different areas of concern.  Predicted noise levels breakdown for the mitigated scenario are shown in Table  C8.1 in Annex C8.

4.6.37    In case residual noise impacts were identified after all practicable direct technical remedies were exhausted, further investigations to explore alternatives or options for reducing the residual impacts should be carried out, especially during the detailed design stage of Road P1.

Luk Keng Tsuen (N3)

4.6.38    Mitigation measures in the form of a 450 m long roadside vertical barrier of 5 m high along the slip road linking eastbound Road P1 and eastbound North Lantau Highway have been proposed.  Residential dwellings at Luk Keng Tsuen (N3) would be protected with the recommended measures.  The location of the proposed mitigation measures is shown in Figure 4.6a .

4.6.39    The prediction results shown in Table C8.1  in Annex C8 indicate that with the adoption of mitigation measures, all residential dwellings are protected from criterion exceedances.

Planning Area 4A & 4B in Siu Ho Wan (N7-1 to N7-39)

4.6.40    Two types of noise mitigation measures have been proposed for this site:

·                      two sections of semi-enclosure (in the form of an L-shaped barrier) of 280 m and 600 m long with absorptive lining located at the northern edge of Road P1 (covering the entire width of eastbound Road P1); and

 

·                      two sections of absorptive cantilever barrier of 125 m and 45 m long, comprising a 8 m vertical section with a 5 m horizontal projection located at 18 m away from the central reserve of Road P1.

 

4.6.41    The location of the proposed mitigation measures is shown in Figure 4.6b.

4.6.42    The results of the mitigated scenario of the traffic noise modelling presented in Table C8.1 in Annex C8 indicate that the above mitigation will protect all residential dwellings from criterion exceedances.

Planning Area 4C in Siu Ho Wan (N7-50 to N7-56)

4.6.43    With the adoption of the mitigation measures along Road P1, as described above, criterion exceedances of up to 7 dB(A) were still predicted at approximately 13 classrooms.  The results in Table C8.1 in Annex C8 shows that the criterion exceedances were dominantly contributed by Road P1.

4.6.44    In view of the residual impacts at the two schools, further mitigation measures have been considered:

·                      putting full enclosure at Road P1; and

·                      re-orientation of the school building.

 

4.6.45    However, these two mitigation measures are found either unfeasible and ineffective due to the fact that:

·                      full enclosure at the road junction is not considered feasible by the Design Engineer as it may cause road sight-line problem;

·                     sensitive uses are found at all facades, therefore, re-orientation of the school building would not be effective to reduce noise impacts.

4.6.46    After exhausting all possible direct mitigation measures, it is recommended that sensitive uses at the following locations shall be provided with window insulation and air-conditioning:

·                      the eastern facade of the primary school at Site 4C facing the internal Access Road;

·                      3/F and above at the western facade of the secondary school at Site 4C facing the internal Access Road;

·                      3/F and above at the southern facade of the assembly hall block of the secondary school at Site 4C facing Road P1; and

·                      top floors at the southern facade of the special rooms block of the secondary school at Site 4C facing Road P1.

4.7              CKWLR : Identification and Assessment of Environmental Impacts

construction phase

Potential Impacts from Project Construction Noise

4.7.1        The potential source of noise during construction phase of the CKWLR is the use of PME for roadwork construction, piling of viaduct foundations and road pavements.

4.7.2        Broadly speaking, construction of the CKWLR can be geographically split into 3 areas and these include:

·                      CKWLR from the existing Yam O Interchange tie in to Penny’s Bay Interchange;

·                      CKWLR from Penny’s Bay Interchange to Route 10-NLYLH Toll Plaza; and

·                      CKWLR from East of Tsing Chau Tsai to Route 10 - Hong Kong Lantau Link (HKLL).

 

4.7.3        Cumulative noise impacts from other concurrent activities for the construction of the NLDFS development, the Theme Park (Phase I and II) and its associated developments (including Road P2 and the Resort Roads), the proposed Road P1 and the PBRL have been accounted for and are addressed in the preceding section, Section 4.5.1.

4.7.4        It is assumed that construction activities for the CKWLR, in general, will be carried out on a 16-hour day (i.e. 0700-2300) and 24 working days per month basis.  Hence assessment of construction noise impacts at each NSR has been conducted to compare the results against the corresponding criteria under the daytime and evening time periods. 

4.7.5        Generally, construction works during restricted hours, i.e. evening time (1900-2300) in this case, are not recommended.  However due to the shortage of time for the completion of certain construction activities, construction works during evening time is likely to be required.  It should be noted that regardless of the results of the construction noise impact assessment for restricted hours, the Noise Control Authority will process the CNP application, once filed, based on the NCO and the relevant technical memoranda taking into account the then prevailing conditions/situations.

4.7.6        As the separation distance from the Siu Ho Wan area to the CKWLR alignment is about 4.5 km and with the addition of terrain shielding, NSRs at the Siu Ho Wan area, including the Planning Area 38 in Tai Ho (N8), the Planning Area 10 above Siu Ho Wan MTRC Depot (N9) and the Planning Area 56 located north of Siu Ho Wan (N10), are excluded from the CKWLR construction noise assessment.

Construction Works during Daytime and Evening Period (0700-2300)

4.7.7        The unmitigated noise levels at each NSR for particular construction activity and the cumulative noise levels have been predicted.  The results are given in Annex C3a, Table C3a.1-C3a.4.  Figures 4.3b to 4.3d and 4.3f show the location of noise assessment points during the construction phase.  The assessment points have been chosen to represent the worst affected NSR.  The range of noise levels predicted at each NSR is presented in Table 4.7a below.

Table 4.7a - Unmitigated Predicted Construction Noise Levels

NSR	Range of  PNL1, dB(A)2	Criteria		Critical activity causing exceedance3
		Daytime	Evening
N1-a (Peng Chau)	25-42	75	60	-
N2-a (Discovery Bay)	22-36	75	60	-
N3-a (Luk Keng Tsuen)	60-65	75	65	-
N5-a (Tso Wan)	44-68	75	60	reclamation and excavation works for CKWLR from east of TCT4 to Route 10 Toll Plaza (F) + works associated with transport infrastructures from Route 10 Toll Plaza to Route 10-HKLL (P)
Note: 1.        PNL stands for Predicted Noise Level. 2.        The range of noise levels presented are the overall cumulative noise levels from construction of CKWLR. 3.        Activity reference as shown in Annex C3a, Tables C3a.1-C3a.4. 4.        TCT stands for Tsing Chau Tsai.

 

Peng Chau (N1)

 

4.7.8        As shown in Table 4.7a, the predicted maximum noise level was 42 dB(A).  No noise exceedance during both daytime and evening has been predicted at Peng Chau (N1) from the construction of CKWLR.  The reason accounting for over 30 dB(A) and 15 dB(A) margin below noise criterion for daytime and evening time respectively was due to the large separation distance (more than 3.8 km) between Peng Chau and the proposed CKWLR alignment.

Discovery Bay (N2)

 

4.7.9        A range of noise levels from 22 dB(A) to 36 dB(A) has been predicted for Discovery Bay (N2).  This indicated that the construction noise levels at Discovery Bay have complied with both the daytime and evening criteria.  Similar to Peng Chau, Discovery Bay is located at a remote distance from CKWLR and hence adverse construction noise impact from CKWLR would not be likely.

Luk Keng Tsuen (N3)

 

4.7.10    The maximum noise level predicted at Luk Keng Tsuen was 65 dB(A).  There was neither noise exceedance during both daytime nor evening.

Tso Wan (N5)

 

4.7.11    For Tso Wan (N5), noise exceedance during daytime is not anticipated.  However, exceedances in the range of 1-8 dB(A) were predicted for evening time (i.e. 1900-2300). 

4.7.12    Reclamation and excavation works for the CKWLR from east of TCT up to Route 10 Toll Plaza and the roadwork construction for the CKWLR from Route 10 Toll Plaza to Route 10 - HKLL were identified from  the assessment to be the critical activities causing noise exceedances. 

4.7.13    According to the assessment results, (details as shown in Annex C3a, Table C3a.4), individual construction activity including filling works and surcharge activity for the platform east of TCT up to Route 10 Toll Plaza and the roadwork activities for the CKWLR from Route 10 Toll Plaza to Route 10 - HKLL themselves have exceeded the evening 60 dB(A) criterion. 

4.7.14    Since noise exceedance was predicted at Tso Wan during evening time, effective mitigation measures and proper environmental control practice should be adopted in order to reduce the noise levels to within the noise standard.  Mitigation measures proposed to reduce the identified noise impacts during evening time are discussed in Section 4.8.1. 

Operational phase

Road Traffic Noise

4.7.15    The NSRs considered in this Project are all located at large distances away from CKWLR, for example, more than 3 km between CKWLR and Peng Chau or Discovery Bay.  The closest NSR to CKWLR is Luk Keng Tsuen, which is located more than 600 m away from CKWLR. 

4.7.16    Tso Wan Village Expansion Area (N6)  and Siu Ho Wan Planning Areas 4A to 4C are both screened by the substantial terrain from CKWLR and therefore it is not included in the assessment.

4.7.17    Owing to the large distances between NSRs and CKWLR and the very substantial terrain screening effect, it is anticipated that there would be no adverse traffic noise impact from CKWLR to the NSRs.  Therefore, no mitigation would be required.

4.8              CKWLR :  Mitigation of Adverse Environmental Impacts

Mitigation for Adverse Construction Noise Impacts

4.8.1        Noise emissions from construction activities can be minimised through good site practice, selecting quiet plant, adopting quieter working methods, erection of barriers to screen the noise source, where appropriate, and posing restriction on the usage of noisy equipment.  The recommended mitigation measures detailed in this section should be incorporated into the Contract Specification in order to ensure the environmental performance of construction works.

4.8.2        Contractors may develop a different package of environmental control measures to meet the required noise standards, but the following illustrates a feasible approach to mitigate the predicted noise impacts during the construction phase:

Good Site Practice

4.8.3        The activities being undertaken for the construction of the CKWLR are unlikely to give rise to adverse daytime noise impacts to the surrounding environment as concluded in the preceding section, Section 4.7.1. However, in order to minimise noise emissions from the works, Contractors shall be required to adopt good site practice and maintain proper on-site management during all times.  The following measures are recommended:

·                      Only well-maintained plant shall be operated on-site and plant should be serviced regularly during the construction works;

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

·                      Silencers or mufflers on construction equipment shall be utilised and be properly maintained during the construction works;

·                      Mobile plant shall be sited as far away from NSRs as possible; and

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

4.8.4        Although it is difficult to quantify the level of noise reduction achieved from incorporation of these elements, the environmental performance of the works would be improved with these control measures.

Selecting Quieter Plant

4.8.5        The use of quiet plant is identified to be a feasible solution to tackle the adverse impacts associated with construction works.  The Contractors may be able to obtain particular models of plant that are quieter than standard types given in GW-TM.  The benefits achievable in this way will depend on the details of the Contractors’ chosen methods of working, and it is considered too restrictive to specify that a Contractor has to use specific items of plant for the construction operations.  It is therefore both preferable and practical to specify an overall plant noise performance specification to apply to 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.

4.8.6        Quiet plant is defined as PME whose actual SWL is less than the value specified in GW-TM for the same piece of equipment.  Examples of SWLs for specific silenced PME taken from a British Standard, namely Noise Control on Construction and Open Sites, BS5228: Part 1: 1997, which are known to be used are given in Table 4.8a.

Table 4.8a - Sound Power Levels for Specific Silenced PME

PME	BS5228 Table no.	Ref no.	SWL, dB(A) max
Breaker	C.2	10	110
Dozer	C.9	2	104
Mobile Crane	C.7	114	101
Concrete Pump	C.6	22	106
Dump truck	C.9	27	105
Excavator/Loader	C.3	97	105
Generator	C.7	62	100
Lorry	C.8	16	108
Concrete truck (mixer)	C.6	35	100
Grader	C.9	11	110
Road Roller	C.8	27	104
Poker Vibrator	C.6	32	100

 

4.8.7        It should be noted that various types of silenced equipment can be found in Hong Kong.  However, the EPD, when processing a CNP application, will apply the noise levels contained in the GW-TM, unless the noise emission of a particular piece of equipment can be validated.

4.8.8        The mitigated noise levels at each NSR, with the use of quiet plant, for each construction activity and the cumulative noise levels have been predicted and the details are given in Annex C3b, Tables C3b.1-C3b.4.  The range of noise levels predicted is presented in Table 4.8b below.

Table 4.8b - Mitigated Construction Noise Levels - via Quiet Plant

NSR	Range of PNL1, dB(A)2	Daytime Criterion, dB(A)	Evening time Criterion, dB(A)
N1-a (Peng Chau)	25-36	75	60
N2-a (Discovery Bay)	22-30	75	60
N3-a (Luk Keng Tsuen)	54-59	75	65
N5-a (Tso Wan)	44-60	75	60
Note: 1.        PNL stands for Predicted Noise Levels. 2.        The noise levels presented are the overall cumulative noise levels (from construction of CKWLR).

 

4.8.9        As addressed in Section 4.7.1, construction noise levels at each NSR complied with the daytime 75 dB(A) criterion.  Noise exceedance was only predicted at Tso Wan (N5) for evening time.  As shown in Table 4.8b above, with the use of quiet plant, the noise levels predicted at Tso Wan (N5) were reduced.  The maximum noise level predicted was 60 dB(A), which complied with the evening 60 dB(A) criterion. 

4.8.10    As compared with the results presented in Table 4.7a (unmitigated noise levels), with the use of quiet plant, a 6 dB(A) reduction in the maximum noise levels was predicted at Peng Chau (N1), Discovery Bay (N2) and Luk Keng Tsuen (N3).  Though no exceedance has been predicted at these NSRs from the construction of CKWLR, this reduction in noise levels will further minimise noise impacts arising from concurrent construction works.

Use of Temporary and Movable Noise Barriers

4.8.11    As addressed in Section 4.5.1,  cumulative noise impacts from the construction of CKWLR together with other concurrent activities for the construction of developments within Northshore Lantau may be induced, particularly at Luk Keng Tsuen (N3) and Tso Wan (N5).  It is thus recommended that temporary and movable noise barriers should be erected at some construction works sites for CKWLR, where appropriate, in order to reduce the identified cumulative noise impacts.

4.8.12    In general, purpose-built noise barriers or screens constructed of appropriate material to be located close to operating PME could give a noise reduction of up to 5 dB(A) (estimated in accordance with the GW-TM).  This level of noise reduction could also be achieved by erecting temporary noise barriers along active work sites.  Certain types of PME, such as generators, can be completely screened giving a total noise reduction of 10 dB(A) or more.

4.8.13    It is anticipated that a movable noise barrier with a suitable footing and a small cantilevered upper portion can be located within a few metres of a static plant and within about 5 m of more mobile equipment such as excavator and mobile crane etc., such that the line of sight could be blocked by the barriers viewed from the NSRs.  The estimated noise reduction by means of screening, provided that the barriers are carefully located, can provide at least 10 dB(A) noise attenuation for static plant and 5 dB(A) for mobile plant.  The noise screening benefit for each plant considered in this assessment is listed below:

·                      Stationary Plant - assuming 10 dB(A) reduction: poker vibrator, concrete pump and generator; and

·                      Mobile Plant - assuming 5 dB(A) reduction: excavator, grader, road roller, mobile crane and concrete truck.

 

4.8.14    The predicted noise levels from the construction of CKWLR, with the use of quiet plant and barriers to reduce the identified cumulative noise impacts associated with all construction works in the Project are presented in Annex C3b and Annex C3c.  The range of noise levels predicted is presented in Table 4.8c below.

Table 4.8c - Mitigated Construction Noise Levels - via Quiet Plant and Erection of Barriers

NSR	Range of Predicted Noise Levels, dB(A)
N3-a (Luk Keng Tsuen)	49-57
N5-a (Tso Wan)	44-60

 

4.8.15    As shown in Table 4.8c, with the use of quiet plant and the erection of noise barriers, the maximum noise level predicted at Luk Keng Tsuen (N3) was reduced by 2 dB(A).  The reduction in noise levels will ameliorate the noise emission from CKWLR construction works and thus reduce the cumulative impacts from concurrent activities.

Construction Noise Impacts at existing Lantau North Country Park and the Proposed Country Park Extension Area

4.8.16    In view of the large separation distance (over 7 km) from the existing nearest boundary of the Lantau North Country Park to the proposed CKWLR alignment, adverse noise impacts from the construction of the CKWLR on the existing Country Park would not be expected.

4.8.17    For the Proposed Country Park Extension Area, noise impact from the construction of CKWLR is envisaged to be limited, for the minimum distance separation from the work site is 400 m. 

Mitigation for Operational Noise Impacts

4.8.18    As concluded in the preceding section, Section 4.7.2, no NSRs are located in the vicinity of the CKWLR and therefore no mitigation measures during the operation phase of CKWLR are required.

4.9              Residual Environmental Impact

Construction Phase

Residual Noise Impact from NLDFS

4.9.1        In view of the large number of construction activities and equipment considered in the Project, without mitigation measures, adverse construction noise impacts to the surrounding environment are likely.

4.9.2        With the implementation of practical noise mitigation measures as recommended in Section 4.6.1, including the use of quiet plant, the erection of noise barriers at active work sites and the reduction on the number of operating PME, noise levels at all NSRs were reduced to comply with the daytime 75 dB(A) criterion.  However, noise exceedances at evening were still predicted at Luk Keng Tsuen (N3), Tso Wan (N5) and the Comprehensive Development Area above the Siu Ho Wan MTRC Depot (N9).  It is therefore recommended that re-scheduling of certain construction activities to avoid evening works are required in order to further mitigate the noise impact to comply with the noise criteria. 

4.9.3        With the avoidance of evening works including reclamation and excavation works for the Northshore and Siu Ho Wan reclamation, roadwork for Northern Reclamation and construction of services infrastructure, noise levels at Luk Keng Tsuen (N3) and the Comprehensive Development Area above Siu Ho Wan MTRC Depot (N9) were then mitigated to within the evening criteria.

4.9.4        The construction activities affecting Tso Wan are recommended not to be carried out during evening and noise impact from evening works at Tso Wan could be eliminated.

4.9.5        Besides, reclamation and excavation works for Siu Ho Wan have been identified to be the critical activities causing noise exceedance at the planned school at the Planning Area 56 north of Siu Ho Wan (N10) during examination periods.  Re-scheduling of these works to avoid the undertaking of these activities during examination periods is recommended to reduce the noise levels to within the 65 dB(A) criterion.

Residual Noise Impact from CKWLR

4.9.6        Noise exceedances were predicted only at Tso Wan (N5) for evening time.  With the use of quiet plant, noise impact at Tso Wan was mitigated to comply with the evening 60 dB(A) criterion.

Operational Phase

Fixed Plant Noise

4.9.7        The operational noise assessment results revealed that exceedance of the relevant noise criteria due to the operation of the Theme Park and other associated developments, and other fixed plant sources identified in the Project is not anticipated.  No specific mitigation measure is considered necessary to further ameliorate the noise impact.

4.9.8        For fireworks displays at Theme Park (Phase I and II), a maximum duration of 5 minutes for mid-level shows and a maximum height of 100 m are recommended for complying with the L_{Aeq, 15 min} 55 dB criterion.

Road Traffic Noise

4.9.9        Unmitigated road traffic noise predictions, as shown in Table C8.1 in Annex C8, suggested that there would be a total of approximately 1130 residential dwellings (including Luk Keng Tsuen and Planning Area 4A & 4B) and 67 classrooms (Planning Area 4C) affected by noise exceeding the relevant EIAO-TM criteria.  With the proposed mitigations as discussed in Section 4.6.2, it is anticipated that noise levels at all residential dwellings in Luk Keng Tsuen (N3-b to N3-d) and Planning Area 4A & 4B in Siu Ho Wan would be within the EIAO-TM criterion of 70 dB(A).

4.9.10    The unmitigated road traffic noise predictions for Planning Area 4C in Siu Ho Wan showed that approximately 67 classrooms would be exposed to levels above the EIAO-TM criterion, predominantly contributed by Road P1.  With the proposed mitigation measures suggested in Section 4.6.2, criterion exceedances are still likely at approximately 13 classrooms.  However, owing to engineering constraints and the ineffectiveness of orientation of building blocks, no further direct mitigation measures are considered applicable.  Since all possible direct mitigation measures have been exhausted, it is therefore recommended that the following locations at the school buildings be provided with window insulation and air-conditioning to reduce the noise impact:

·                      the eastern facade of the primary school at Site 4C facing the internal Access Road;

·                      3/F and above at the western facade of the secondary school at Site 4C facing the internal Access Road;

·                      3/F and above at the southern facade of the assembly hall block of the secondary school at Site 4C facing Road P1; and

·                      top floors at the southern facade of the special rooms block of the secondary school at Site 4C facing Road P1.

 

Rail Noise

4.9.11    As discussed in Section 4.5.2, all the predicted railway noise levels at existing and planned NSRs will comply with the statutory requirements of the NCO and the EIAO-TM.  Adverse noise impacts from operational trains are not expected.

Helicopter Noise

4.9.12    As the helicopter flight path is an emergency path to be used only in adverse weather, the noise impact predicted (exceedance of 1 dB(A)) at the planned residential development at Siu Ho Wan (N7 - Planning Area 4A to 4C) would be minimal.   

4.10          Environmental Monitoring and Audit

Construction Phase

4.10.1    Noise arising from construction activities associated with the Project and the construction of CKWLR will impact upon NSRs as assessed in Section 4.5.1 and Section 4.7.1 respectively.  The primary noise sources are the use of PME such as excavator, lorry, loader, bulldozer, grader, mobile crane and poker vibrator.  Without implementing any noise mitigation measures, the construction noise standards given in the EIAO-TM and the GW-TM will be exceeded at some of the representative NSRs.

4.10.2    It is anticipated that if the suggested mitigation measures described in Section 4.6.1 and Section 4.8.1 can be successfully applied, the noise levels experienced by the affected receivers will be reduced to within the noise standards.  The mitigation measures proposed include the use of quieter plant for some PME, the erection of noise barriers at active work sites, the reduction on the number of operating PME and the restriction on evening works for some construction activities.

4.10.3    Noise monitoring requirements have been recommended in the EM&A Manual in order to ensure compliance with the noise standards.  It is recommended that noise monitoring should be conducted as part of the EM&A programme during the construction phase of the Project at Peng Chau (NM1), Discovery Bay (NM2), Luk Keng Tsuen (NM3), Tso Wan (NM4), Planning Area 38 in Tai Ho (NM7), Planning Area 10 above Siu Ho Wan MTRC Depot (NM8) and Planning Area 56 located north of Siu Ho Wan (NM9).

Operational Phase

4.10.4    No exceedance of the relevant noise criteria was predicted due to the operation of the Theme Park and its other associated developments, and other fixed plant identified in the Project.  No specific mitigation measure is considered necessary to further ameliorate the noise impact.

4.10.5    For fireworks displays at Theme Park (Phase I and II), a maximum duration of 5 minutes for mid-level shows and a maximum height of 100 m are recommended for complying with the L_{Aeq, 15 min} 55 dB criterion.

4.10.6    Road traffic noise criteria exceedances were predicted at residential dwellings in Luk Keng Tsuen and Planning Area 4A & 4B and classrooms in Planning Area 4C in Siu Ho Wan.  It was predicted that the proposed mitigation measures in Section 4.6.1 are likely to protect all residential dwellings from criterion exceedance.  However, residual impact was predicted at the schools in Planning Area 4C.  While all practicable direct mitigation measures were exhausted, it was recommended that some classrooms be provided with window insulation and air-conditioning.

4.10.7    Noise monitoring requirements have been recommended in the EM&A Manual in order to ensure compliance with the noise standards. It is recommended that noise monitoring should be conducted as part of the EM&A programme at NM1 (Sea Crest Villa, Peng Chau), NM2 (Crestmont Villa, Discovery Bay), NM3 (Luk Keng Tsuen), NM4 (Tso Wan), NM5 (Tso Wan Village Expansion Area) and NM6 (Planning Area 4A to 4C in Siu Ho Wan) during the operational period of the project.

4.10.8    The noise monitoring specifications can be referred in the Project EM&A Manual.

4.11          Conclusions

Construction Phase

Construction Phase - NLDFS

4.11.1    Noise during the construction phase of the Project would impact on the surrounding environment.  The use of PME is the primary source of noise. 

4.11.2    Unmitigated construction activities associated with the Project would cause  exceedances at NSRs of both daytime and evening construction noise standards stipulated in the EIAO-TM and the GW-TM.  Maximum noise level of 82 dB(A) was predicted at the residential development site above Siu Ho Wan MTRC Depot (N9).

4.11.3    Adequate control measures would be required for general construction works to meet the relevant noise standards.  Mitigation measures including the use of quiet plant, the erection of noise barriers, and  the reduction on the number of PME usage were first recommended. 

4.11.4    With the recommended mitigation measures in place, noise levels at all NSRs were reduced to comply with the daytime 75 dB(A) criterion.  However, noise exceedances at evening were still predicted at Luk Keng Tsuen (N3), Tso Wan (N5) and the planned residential development site above Siu Ho Wan MTRC Depot (N9).  It is therefore recommended that re-scheduling of certain construction activities to avoid evening works are required in order to further mitigate the noise impact to comply with the noise criteria. 

4.11.5    With the avoidance of evening works including reclamation and excavation works for Northshore and Siu Ho Wan, roadwork for Northern Reclamation and construction of services infrastructure, noise levels at Luk Keng Tsuen (N3) and the planned residential development above Siu Ho Wan MTRC Depot (N9) were then mitigated to within the evening criteria.

4.11.6    The construction activities affecting Tso Wan are recommended not to be carried out during evening and therefore noise impact from evening works at Tso Wan could be eliminated.

4.11.7    Besides, reclamation and excavation works for Siu Ho Wan have been identified to be the critical activities causing noise exceedance at the planned school at the Planning Area 56 north of Siu Ho Wan (N10) during examination periods.  Re-scheduling of these works to avoid the undertaking of these activities during examination periods is recommended to reduce the noise levels to within the 65 dB(A) criterion.

4.11.8    Night-time construction works were limited to the reclamation stage for Theme Park Phase I development.  The plant used include the TS dredger, the CS dredger and the grab dredger.  Compliance of the night-time 45 dB(A) criterion at NSRs, namely Peng Chau and Discovery Bay, were achieved.

Construction Phase - CKWLR

4.11.9    Noise exceedances in the range of 1-8 dB(A) were predicted at Tso Wan (N5) during evening only without mitigation measures.  With the use of quiet plant, noise impact at Tso Wan was mitigated to comply with the evening 60 dB(A) criterion.

Operational Phase

Railway Noise

4.11.10    The predicted railway noise levels at existing and planned NSRs (including Luk Keng Tsuen and the planned uses in Areas 4A to 4C) will comply with the statutory requirements of the NCO and the EIAO-TM.  Adverse noise impacts from operational trains are not expected.

Fixed Plant Noise

4.11.11    The operational noise assessment results revealed that exceedance of the relevant noise criteria due to the operation of the Theme Park and other associated developments is not anticipated.  No specific mitigation measure is considered necessary to further ameliorate the noise impact.

4.11.12    For other fixed plant noise sources, such as the Penny’s Bay GTP, the proposed sewage pumping station at Penny’s Bay, the proposed PTIs at Yam O and Penny’s Bay and the Sewage and Water Treatment Works at Siu Ho Wan area, etc., it is anticipated that their impacts on NSRs are likely to be minimal and within the relevant criteria.

4.11.13    For other developments proposed under the NLDFS, including the Northshore Development area and the Eco Park proposed at Luk Keng Tsuen, it is noted that no noise sources have been identified.

Road Traffic Noise

4.11.14    Unmitigated road traffic noise predictions, as shown in Table C8.1 in Annex C8, suggested that there would be approximately 1130 in total residential dwellings and 67 classrooms at Luk Keng Tsuen and Planning Area 4A to 4C in Siu Ho Wan affected by noise impact exceeding the relevant EIAO-TM criteria.  Road P1 has been identified as the main contributor.  With the proposed mitigation as discussed in Section 4.6.2, it is anticipated that noise levels at all residential dwellings in Luk Keng Tsuen (N3-b to N3-d) and Planning Area 4A & 4B in Siu Ho Wan would be within the EIAO-TM criterion of 70 dB(A). Therefore, there would be no above criterion noise impact.

4.11.15    With the proposed mitigation measures suggested in Section 4.6.2, criterion exceedances are still likely at approximately 13 classrooms in Siu Ho Wan.  However, owing to engineering constraints and the ineffectiveness of re-orientation of building blocks, no further direct mitigation measures are considered applicable.  Since all possible direct mitigation measures have been exhausted, it is therefore recommended in Section 4.6.2 that some of the classrooms be provided with window insulation and air-conditioning to reduce the noise impact.

Helicopter and Aircraft Noise

4.11.16    As the helicopter flight path is an emergency path to be used only in adverse weather, the noise impact predicted (minor exceedance of 1 dB(A)) at the planned residential development at Siu Ho Wan (N7 - Planning Area 4A to 4C) would be minimal.

4.11.17    As no NSRs are located within the NEF 25 zone, no adverse aircraft noise impacts are anticipated. An L_max 75 dB(A) noise level from aircraft were predicted in both Planning Area 4A to 4C at Siu Ho Wan and Tso Wan.

4.11.18    The findings of the EIA are summarised in Table 4.11a.

Table 4.11a  Impact Summary

Issue	Construction Phase	Operational Phase
Assessment Points Considered	·       N1-a (Peng Chau) ·       N2-a (Discovery Bay) ·       N3-a (Luk Keng Tsuen) ·       N4-a (Lantau North Country Park) ·       N4’-b to N4’-d (Proposed Country Park Extension Area) ·       N5-a (Tso Wan) ·       N8-a (Planning Area 38 in Tai Ho) ·       N9-a (Planning Area 10 above Siu Ho Wan MTRC Depot) ·       N10-a (Planning Area 56 north of Siu Ho Wan MTRC Depot)	·       N1-a (Peng Chau) ·       N2-a (Discovery Bay) ·       N3-b to N3-d (Luk Keng Tsuen) ·       N4-a (Lantau North Country Park) ·       N4’-b to N4’-d (Proposed Country Park Extension Area) ·       N6-a to N6-c (Tso Wan Village Expansion Area) ·       N7-1 to N7-39 (Planning Area 4A & 4B in Siu Ho Wan) ·       N7-50 to N7-56 (Planning Area 4C in Siu Ho Wan)
Relevant Criteria	·       Daytime (0700-1900 hours) construction noise standards stipulated in the EIAO-TM is Leq 30 min 75 dB(A) for all domestic premises and 70 dB(A) for educational premises (65 dB(A) during examination) on any day not being a Sunday or general holiday for general construction works.   ·       General construction works during the restricted hours follow the criteria set in the GW-TM.  These are:   1.     LAeq, 5min 60 dB, 65 dB and 70 dB for area with Area Sensitivity Rating of A, B and C respectively for all days during the evening (1900-2300 hours) and general holidays (including Sundays) during the day and evening (0700-2300 hours); and   2.     Noise criteria of LAeq, 5min 45 dB, 50 dB and 55 dB for area with Area Sensitivity Rating of A, B and C respectively for all days during the night-time (2300-0700 hours).   ·       There are no statutory limits or guidelines for Country Parks.	Railway Noise ·       According to the IND-TM, the daytime & evening (0700-2300 hours) noise limits are LAeq 30min 60 dB, 65 dB and 70 for NSRs with Area Sensitivity Rating of A, B and C respectively.   ·       According to the IND-TM, the night-time (2300-0700 hours) noise limits are LAeq 30min 50 dB, 55 dB and 60 dB for NSRs with Area Sensitivity Rating of A, B and C respectively.  In addition, the EIAO-TM has also recommended a criterion of Lmax 85 dB(A) during these hours.   Fixed Plant Noise ·       The EIAO-TM requires that all fixed noise sources be located and/or designed such that:   1.     the total fixed source noise level at the façade of the nearest NSR is at least 5 dB(A) lower than the appropriate ANL as specified in the IND-TM;   2.     where the prevailing pre-Project noise level in the area is 5 dB(A) or more below the appropriate ANL, the total fixed source noise level must not exceed this pre-Project noise level.   According to the EIAO-TM/IND-TM: ·       the daytime & evening (0700-2300 hours) noise limit for Peng Chau and Discovery Bay is 50 dB(A) while the night-time (2300-0700 hours) noise limit for these NSRs is 45 dB(A).   ·       the daytime & evening (0700-2300 hours) noise limit for Luk Keng Tsuen is 60 dB(A) while the night-time (2300-0700 hours) noise limit for these NSRs is 50 dB(A).   ·       the daytime & evening (0700-2300 hours) noise limit for Tso Wan Village Expansion Area is 65 dB(A) while the night-time (2300-0700 hours) noise limit for these NSRs is 55 dB(A).   ·       the daytime & evening (0700-2300 hours) noise limit for Planning Area 4A to 4C in Siu Ho Wan is 70 dB(A) while the night-time (2300-0700 hours) noise limit for these NSRs is 60 dB(A).   Fireworks Noise ·       The criterion of LAeq 15 min 55 dB(A) was used for domestic premises.   Road Traffic Noise ·       The EIAO-TM requires that road traffic noise levels outside the facades of domestic premises which rely upon openable windows for ventilation should not exceed L10 1hour 70 dB(A) at domestic premises and 65 dB(A) at educational premises.   ·       There are no statutory limits or guidelines for Country Parks for all types of operational noise sources..
Potential Impacts	Construction Works during daytime & evening ·       Noise emitted by the use of PME is the major source of impact during construction.   ·       A range of 27-63 dB(A) was predicted at N1-a (Peng Chau).   ·       A range of 32-64 dB(A) was predicted at N2-a (Discovery Bay).   ·       A range of 47-79 dB(A) was predicted at N3-a (Luk Keng Tsuen).   ·       A range of 56-79 dB(A) was predicted at N5-a (Tso Wan).   ·       A range of 55-71 dB(A) was predicted at N8-a (Planning Area 38 in Tai Ho).   ·       A range of 68-82 dB(A) was predicted at N9-a (Planning Area 10 at Siu Ho Wan MTRC Depot).   ·       A range of 60-75 dB(A) was predicted at the school of N10-a (Planning Area 56 north of Siu Ho Wan).   ·       A range of 49-64 dB(A) was predicted at the Proposed Country Park Extension Area from the construction of the PBRL.   Construction Works during night-time ·       As night-time construction activities are concentrated at Penny’s Bay, only Peng Chau and Discovery Bay will be affected.   ·       A range of 37-43 dB(A) was predicted at N1-a (Peng Chau).   ·       A range of 39-45 dB(A) was predicted at N2-a (Discovery Bay).	Railway Noise ·       The predicted noise levels at NSRs (including Luk Keng Tsuen and the Planning Area 4A to 4C) will comply with the statutory requirements of the NCO and the EIAO-TM.  Adverse noise impact from operational trains are not expected.   ·       Leq, 30min noise levels in the range of 49 dB(A) to 56 dB(A) were predicted at the Proposed Country Park Extension Area, with Lmax level ranges between 57 to 65 dB(A)..   Fixed Plant Noise ·       Predicted noise levels at Peng Chau (N1-a) and Discovery Bay (N2-a) from daytime and night-time operation of Theme Park (Phase I and II) were within the EIAO-TM/IND-TM criterion.   ·       Noise Impact from the operation of Theme Park (Phase III) Extension on NSRs was predicted to be minimal.   ·       Noise impact from the GTP was predicted to be minimal and well within the EIAO-TM/IND-TM criterion at all NSRs.  The  noise level predicted at the Proposed Country Park Extension Area is approximately 59 dB(A).   ·       Noise impact from the proposed sewage pumping station was predicted to be minimal, given its relatively large distances to the NSRs.   ·       Noise impact from the fixed plant of Penny’s Bay Rail Link was predicted to be minimal to the NSRs due to the large separation distances and noise shielding between the noise source and the NSRs.  The EIAO-TM/IND-TM criteria exceedances are not anticipated.   ·       Noise impacts from the PTIs at Yam O and Penny’s Bay were predicted to be well within the referenced IND-TM criterion.  Noise levels in the range of 38-43 dB(A) were predicted in the Proposed Country Park Extension Area from the Penny’s Bay PTI.   ·       Noise emitted from the operation of the Tsing Chau Tsai East recreational area would not have a significant impact on Tso Wan and the Tso Wan Village Expansion Area.  Road traffic noise from Route 10-NLYLH was identified to be the dominant source.   ·       Noise generated from the Sewage and Water Treatment Works at Siu Ho Wan could be shielded by the residential towers on the MTRC Depot redevelopment, as such noise impact is expected to be limited.   ·       Given the large separation distance between the North Lantau Refuse Transfer Station and the closest NSR, i.e. the Planning Areas 4A to 4C, adverse noise impact would not be anticipated.   ·       Noise impact from other fixed plant sources, such as the vehicle parking areas, the future Container Terminal development, the water recreation centre and the proposed ventilation facilities at Yam Tsai Tunnel, would be limited.   Fireworks Noise ·       With the careful choosing of the types of fireworks items to be used in the Theme Park, the noise emission from the fireworks displays will comply with the LAeq, 15min 55 dB(A) reference criterion at Peng Chau (N1-a) and Discovery Bay (N2-a).   ·       It is anticipated that maximum levels of approximately 85 dB(A) would be perceived at Peng Chau (N1-a) and Discovery Bay (N2-a).  Such maximum levels are from the effects related to individual fireworks items.   Road Traffic Noise ·       Traffic noise impact at Peng Chau, Discovery Bay and the existing Lantau North Country Park was anticipated to be minimal due to their large separation distances away from the noise source.   ·       Based on the Route 10 EIA Report, mitigated road traffic noise levels at the existing Tso Wan village houses were predicted to be in the range of 55 - 70 dB(A).   ·       Predicted noise levels at the proposed Tso Wan Village Expansion Area are 54 dB(A) for the three assessment points and are well within the EIAO-TM criterion.   ·       Minor noise exceedance of 1 dB(A) was predicted at Luk Keng Tsuen.  Road P1 and its associated slip roads, and the existing NLH were identified to be the main contributor.   ·       Noise exceedance of up to 6 dB(A) affecting approximately 1120 residential dwellings was predicted at the Planning Area 4A & 4B.  Road P1 was identified to be the dominant source.   ·       Noise exceedance of up to 12 dB(A) affecting approximately 67 classrooms was identified at the proposed educational institutions at Site 4C.  Road P1 was identified to be the dominant source.   ·       Noise levels in the range of 40-70 dB(A) were predicted at the Proposed Country Park Extension Area.   Helicopter Noise ·       Minor exceedance of 1 dB(A) was predicted at the planned residential development at Siu Ho Wan.  However, the helicopter flight path is an emergency path to be used only in adverse weather and thus noise impact is minimal.   Aircraft Noise ·       No NSRs are located within the NEF 25 zone.  An Lmax 75 dB(A) noise level was estimated in both the Planning Area 4A to 4C at Siu Ho Wan and Tso Wan.
Mitigation Measures	·       Where available, use of quiet plant at all construction work sites.   ·       Use of temporary and movable noise barriers, along the following active work sites: 1.     construction sites near Yam O Interchange 2.     Yam O works area 3.     construction of the CKWLR (from Yam O to Penny’s Bay Interchange) 4.     construction of Road P2 (from Northern Development to Theme Park West) 5.     construction of the Access Road at Yam O 6.     construction of the PBRL (in particular at the Yam O Station) 7.     slope protection work along the eastern boundary of Tsing Chau Tsai 8.     reclamation works for Northshore (Yam O Bay to To Kau Wan) 9.     reclamation works for Siu Ho Wan 10.  construction of Road P1 (from Siu Ho Wan to Yam O) 11.  construction of roadworks for Northshore Reclamation 12.  construction of roadworks for Eastern Reclamation 13.  construction of roadworks for Siu Ho Wan 14.  construction of services infrastructure which was to be built along the road alignment such as CKWLR, Road P2, Access Road, Road P1.   ·          Restriction on the Usage of Operating PME (Reducing the number of plant for some of the PME in construction activities), this includes: 1.        Filling reclamation for Northshore (Yam O Bay to To Kau Wan) 2.        Dredging for Siu Ho Wan 3.        Filling reclamation for Siu Ho Wan 4.        Surcharge placement for Siu Ho Wan   ·          Restriction on Evening Works 5.     Dredging for Northshore (Yam O Bay to To Kau Wan) 6.     Placement of seawall for Northshore (Yam O Bay to To Kau Wan) 7.     Filling reclamation for Northshore (Yam O Bay to To Kau Wan) 8.     Surcharge placement for Northshore (Yam O Bay to To Kau Wan) 9.     Dredging for Siu Ho Wan 10.  Placement of seawall for Siu Ho Wan 11.  Filling reclamation for Siu Ho Wan 12.  Surcharge placement for Siu Ho Wan 13.  Road surfacing /construction for Northern Reclamation 14.  Construction of services infrastructures during Phase II 15.  All the major construction activities considered affecting Tso Wan   ·          Re-scheduling of reclamation and excavation works at Siu Ho Wan to avoid exceedance during examination periods.	Railway Noise ·       As the predicted railway noise levels at NSRs complied with the statutory requirements of the NCO and the EIAO-TM, no specific mitigation measures are required.   Fixed Plant Noise ·       No criteria exceedances were predicted for operational noise impact from the Theme Park and other associated developments and thus no mitigation measures are required.    ·       However, the following structures which may further reduce the noise impacts would be provided in association with the Theme Park Project development: 1.     5 m - 9 m earth berm encircling the Theme Park 2.     9 m earth berm encircling the sewage pumping station 3.     9 m earth berm encircling the gas turbine plant   ·       For fireworks displays at Theme Park (Phase I and II), a maximum duration of 5 minutes for mid-level shows and a maximum height of 100 m are recommended.   ·       As noise impacts from other fixed plant noise sources, such as the Penny’s Bay GTP, the proposed sewage pumping station at Penny’s Bay, the proposed PTIs at Yam O and Penny’s Bay and the Sewage and Water Treatment Works, are minimal, no specific mitigation measures are required.   Road Traffic Noise ·       Mitigation measures in the form of a 450 m long roadside vertical barrier of 5 m high along the slip road linking eastbound Road P1 and eastbound NLH have been proposed to mitigate the noise impact at Luk Keng Tsuen.   ·       Two types of mitigation measures have been proposed for protecting the residential development at Sites 4A & 4B (Figure 4.6b refers): 1.        two sections of semi-enclosure (in the form of an L-shaped barrier) of 280 m and 600 m long with absorptive lining located at the northern edge of Road P1 (covering the entire width of eastbound Road P1)   2.        two sections of absorptive cantilever barrier of 125 m and 45 m long, comprising a 8 m vertical section with a 5 m horizontal projection located at 18 m away from the central reserve of Road P1.   ·       With the adoption of direct mitigation measures, exceedance of up to 7 dB(A) was still predicted at approximately 13 classrooms at Site 4C.   ·       Sensitive uses at the following locations at Site 4C shall be provided with window insulation and air-conditioning: 1.     the eastern facade of the primary school at Site 4C facing the internal Access Road; 2.     3/F and above at the western facade of the secondary school at Site 4C facing the internal Access Road; 3.     3/F and above at the southern facade of the assembly hall block of the secondary school at Site 4C facing Road P1; and 4.     top floors at the southern facade of the special rooms block of the secondary school at Site 4C facing Road P1.
Cost Estimation for Mitigation Measures		·       Proposed Noise Barrier (excluding the foundation cost): HK$68,000,000. ·       Proposed Noise Insulation: HK$198,300.
Environmental Acceptability	Acceptable	Acceptable