1 INTRODUCTION

3. NOISE

3.1 NOISE PARAMETERS

3.1.1	The construction noise level shall be measured in terms of the A-weighted equivalent continuous sound pressure level (Leq). Leq(30 min) shall be used as the monitoring parameter for the time period between 0700-1900 hours on normal weekdays. For all other time periods, Leq(5 min) shall be employed for comparison with the Noise Control Ordinance (NCO) criteria.
3.1.2	As supplementary information for data auditing, statistical results such as L₁₀ and L₉₀ shall also be obtained for reference. A sample data record sheet is shown in Appendix B2 for reference.

3.2 MONITORING EQUIPMENT

3.2.1	As referred to in the Technical Memorandum (TM) issued under NCO, sound level meters in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1) specifications shall be used for carrying out the noise monitoring. Immediately prior to and following each noise measurement the accuracy of the sound level meter shall be checked using an acoustic calibrator generating a known sound pressure level at a known frequency. Measurements may be accepted as valid only if the calibration level from before and after the noise measurement agree to within 1.0dB.
3.2.2	Noise measurements should not be made in the presence of fog, rain, wind with a steady speed exceeding 5 m/s or wind with gusts exceeding 10 m/s. The wind speed shall be checked with a portable wind speed meter capable of measuring the wind speed in m/s.
3.2.3	The ET is responsible for the provision of the monitoring equipment. He shall ensure that sufficient noise measuring equipment and associated instrumentation are available for carrying out the baseline monitoring, regular impact monitoring and ad hoc monitoring. All the equipment and associated instrumentation shall be clearly labelled.

3.3 MONITORING LOCATIONS

3.3.1

Based on the EIA findings there may be residual impacts therefore potential noise sensitive receptors have been identified. The locations of noise monitoring stations are shown in Figure 3.1

3.3.2

Owing to the nature of the works under the project, construction activities will shift from one location to another from time to time. The ET shall select the monitoring locations from those in Figure 3.1 based on the locations of the construction activities and seek approval from ER and agreement from the IEC and EPD of the proposal. The monitoring locations should be chosen based on the following criteria :

At locations close to the major site activities which are likely to have noise impacts
Close to the most affected existing noise sensitive receivers
For monitoring locations located in the vicinity of the sensitive receivers, care should be taken to cause minimal disturbance to the occupants during monitoring.

3.3.3

The monitoring station shall normally be at a point 1 m from the exterior of the sensitive receivers building facade and be at a position 1.2 m above the ground. If there is problem with access to the normal monitoring position, an alternative position may be chosen, and a correction to the measurements shall be made. For reference, a correction of +3dB(A) shall be made to the free field measurements. The ET shall agree with the IEC and EPD on the monitoring position and the corrections adopted. Once the positions for the monitoring stations are chosen, the baseline monitoring and the impact monitoring shall be carried out at the same positions.

3.4 IMPACT MONITORING

3.4.1

Noise monitoring shall be carried out at all the designated monitoring stations. The monitoring frequency shall depend on the scale of the construction activities. The following is an initial guide on the regular monitoring frequency for each station on a per week basis when noise generating activities are underway:

One set of measurements between 0700-1900 hours on normal weekdays.

3.4.2	General construction work carrying out during restricted hours is controlled by Construction Noise Permit (CNP) system under the NCO.
3.4.3	In case of non-compliance with the construction noise criteria, more frequent monitoring as specified in the Action Plan in Section 3.5 shall be carried out. This additional monitoring shall be continued until the recorded noise levels are rectified or proved to be irrelevant to the construction activities.
3.4.4	A schedule on the compliance monitoring shall be submitted to the ER, EPD and IEC for approval before the monitoring starts.

3.5 EVENT AND ACTION PLAN FOR NOISE

3.5.1 The Action and Limit levels for construction noise are defined in Table 3.1. Should non-compliance of the criteria occur, action in accordance with the Action Plan in Table 3.2, shall be carried out.

Table 3.1 Action and Limit Levels for Construction Noise

Time Period	Action Level	Limit Level
0700-1900 hours on normal weekdays	When one documented complaint is received	75* dB(A)

* Reduce to 70 dB(A) for schools and 65 dB(A) during school examination periods

Note : If works are to be carried out during restricted hours, the conditions stipulated in the construction noise permit issued by the Noise Control Authority have to be followed.

Table 3.2 Event / Action Plan for Construction Noise

EVENT	ACTION
	ET	IEC	ER	CONTRACTOR
Action Level	Identify source, investigate the causes of exceedance and propose remedial measures; Notify IEC and Contractor; Report the results of investigation to the ER and Contractor; Discuss with the Contractor and formulate remedial measures; Increase monitoring frequency to check mitigation effectiveness;	1. Review the analysed results submitted by the ET; Review the proposed remedial measures by the Contractor and advise the ER accordingly; Supervise the implementation of remedial measures.	Confirm receipt of notification of failure in writing; Notify Contractor Require Contractor to propose remedial measures for the analysed noise problem; Ensure remedial measures are properly implemented.	1. Submit noise mitigation proposals to IEC; 2. Implement noise mitigation proposals.
Limit Level	Identify source; Inform IEC, ER, EPD and Contractor; Repeat measurements to confirm findings; Increase monitoring frequency; Carry out analysis of Contractor’s working procedures to determine possible mitigation to be implemented; Inform IEC, ER and EPD the causes & actions taken for the exceedances. Assess effectiveness of Contractor’s remedial actions and keep IEC, EPD and ER informed of the results; If exceedance stops, cease additional monitoring.	Discuss amongst ER, ET, and Contractor on the potential remedial actions; Review Contractors remedial actions whenever necessary to assure their effectiveness and advise the ER accordingly; Supervise the implementation of remedial measures.	Confirm receipt of notification of failure in writing; Notify Contractor; Require Contractor to propose remedial measures for the analysed noise problem; Ensure remedial measures properly implemented; If exceedance continues, consider what portion of the work is responsible and instruct the Contractor to stop that portion of work until the exceedance is abated.	Take immediate action to avoid further exceedance Submit proposals for remedial to IEC within 3 working days of notification; Implement the agreed proposals; Resubmit proposals if problem still not under control; Stop the relevant portion of works as determined by the ER until the exceedance is abated.

3.6 NOISE MITIGATION MEASURES

3.6.1

The EIA report has recommended construction noise control and mitigation measures during construction and operational phases.

CONSTRUCTION PHASE

3.6.2

The Contractor shall be responsible for the design and implementation of these measures. The key measures are:

Use of quieter equipment during construction of Roads D1, D8, P2 and piling works for noise barriers close to Areas 51, 57, 65, 72, 73 and 74;
Use of movable noise barriers for particular plant during construction of Road D1 close to Areas 65B & 65C, Road D8 near Area 72 and piling works for noise barriers, and at Road P2 near Area 72 school during construction of Road P2;
Limit the number of plant operating during construction of Road D1 close to Area 65C school;

3.6.3	The number and the type of plant for each construction activity to be used during the construction period are listed in Appendix H.
3.6.4	In addition, good site practices are also recommended as follows:

Further reducing the number of noisy PMEs or re-scheduling the construction tasks close to Area 65C school during the examination period;
Noisy equipment and activities shall be sited by the contractor as far from sensitive receivers;
Intermittent noise activities shall be scheduled to minimize exposure of nearby NSRs to high levels of construction noise;
Idle equipment shall be turned off or throttled down;
Noisy equipment shall be properly maintained and used no more often than is necessary;
Construction activities shall be planned so that parallel operation of several sets of equipment close to a given receiver is avoided;

Where possible, the numbers of concurrently operating items of plant shall be reduced through sensitive programming; and
A noise monitoring programme shall be instigated.

3.6.5

The implementation schedule for the mitigation measures is presented in Appendix C2. On the other hand, impact prediction review checklist (Appendix F2) should be employed to check the extent of discrepancy between the actual and the predicted impact at the designated monitoring stations. ET should estimate the efficiency of the proposed mitigation and plan carefully for the ongoing construction activities.

3.6.6

If the above measures is not sufficient to restore the construction noise to an acceptable levels upon the advice of ET, the Contractor shall liaise with the ET and ER on some other mitigation measures, propose to IEC and EPD for approval, and carry out the mitigation measures.

OPERATIONAL PHASE
3.7 OPERATIONAL PHASE NOISE MONITORING

3.7.1

As the noise sensitive receivers close to the proposed road will be exposed to traffic noise during the operational phase, a noise monitoring programme shall be developed to include noise measurements at noise sensitive receivers during the peak traffic hour. The programme shall be carried out by the Environmental Team (ET) to ensure that the traffic noise levels are comparable to those predicted in the EIA under the full provision of the mitigation measures recommended. The Territory Development Department (TDD) will be responsible for the operational phase monitoring.

NOISE PARAMETERS

3.7.2

The traffic noise level shall be measured twice within the first year of the road opening. Measurement shall be made in terms of the A-weighted L₁₀ over three half-hour periods during the peak traffic hour. Other metrics like L_eq may be added as seen fit. A sample data record sheet is shown in the Appendix G. More details could be referred to Section 3.7.3.

MONITORING EQUIPMENT

3.7.3

Sound level meters to be used shall be in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1) specifications for carrying out the noise monitoring. Immediately prior to and following each noise measurement the accuracy of the sound level meter shall be checked using an acoustic calibrator generating a known sound pressure level at a known frequency. Measurements may be accepted as valid only if the calibration level from before and after the noise measurement agree to within 1.0 dB(A).

3.7.4.

Noise measurement should be made in accordance with standard acoustical principles and practices in relation to weather conditions

3.7.5.

The ET Leader is responsible for the provision and maintenance of the monitoring equipment. All the equipment and associated instrumentation shall be clearly labelled

MONITORING LOCATIONS

3.7.6

The noise monitoring locations should be at NSRs located in the vicinity of recommended direct technical remedies. The recommended noise monitoring locations for the worst case scenario (with development to the south of Road D1) and the situation without development to the south of Road D1 are shown in Figures 3.2 and 3.3 respectively. The monitoring locations would be at the 10/F & 30/F of the selected residential building. Detail descriptions are summarised in Tables 3.3 and 3.4. However, the exact locations where the noise monitoring conducted shall be confirmed after the completion of Roads D1, D8 & D10 and shall be agreed with the EPD. In order to make an easy checking of the relationship between the predicted and measured noise levels, the suggested monitoring stations are same as the assessment points used in the EIA.

Table 3.3 Noise Monitoring Stations during Operational Phase for Worst Case Scenario (With Development to the South of Road D1)

Noise Monitoring Station	EIA Assessment Point	Noise Monitoring Location
OM1	NSR 271	Area 65B
OM2	NSR 638	Area 65D (southern façade)
OM3	NSR 207	Area 67B (southern façade)
OM4	NSR 209	Area 67B (western façade)
OM5	NSR 218	Area 72
OM6	NSR 825	Area 86
OM7	NSR 828	Area 86
OM8	NSR 102	Future Development to the south of Road D1 near Area 65D (facing Road D10)

Note: * Monitoring point bases on the indicative layout which is required to be confirmed.

Table 3.4 Noise Monitoring Stations during Operational Phase for the Scenario Without Development to the South of Road D1

Noise Monitoring Station	EIA Assessment Point	Noise Monitoring Location
OM1	NSR 271	Area 65B
OM2	NSR 638	Area 65D (southern façade)
OM3	NSR 207	Area 67B (southern façade)
OM4	NSR 209	Area 67B (western façade)
OM5	NSR 218	Area 72
OM6	NSR 825	Area 86
OM7	NSR 828	Area 86

3.7.7	When alternative monitoring locations are proposed, the monitoring locations shall be chosen based on the following criteria:

they shall be similarly exposed to potential noise impacts;
they shall be close to the noise sensitive receivers; and
they shall be located so as to cause minimal disturbance to the occupants.

3.7.8

The operational noise monitoring shall be carried out a distance of 1 m from the openable window and 1.2 m above the floor level of the noise sensitive receivers identified. The ET Leader shall agree with the IEC on any necessary corrections adopted.

BASELINE MONITORING

3.7.9

No baseline operational noise monitoring is required.

IMPACT MONITORING

3.7.10

Traffic noise monitoring shall be carried out at all the designated traffic noise monitoring stations. The following is an initial guide on the traffic noise monitoring requirements during the operational phase:

one set of measurements whether it is in the morning or afternoon traffic peak hour on normal weekdays;
a concurrent census of traffic flow and percentage heavy vehicle shall be obtained for far-side and near-side of the road and the existing road network in the vicinity of each measuring point;
average vehicle speed estimated for far-side and near-side of the road and the existing road network in the vicinity of each measuring point; and
the two sets of monitoring data should be obtained within the first year of operation.

Measured noise levels should be compared with predicted noise levels by applying appropriate conversion corrections to allow for the traffic conditions at the time of measurement. Appendix G shows a sample data record sheet for operational noise monitoring.

3.7.11	Each set of measurements shall include three measurements of 30 minutes. The parameters L₁₀, L_eq, L₉₀ and L_max will be recorded for data auditing and reference.
3.7.12	The exact timing shall be confirmed with the TDD and agreed with EPD

NOISE MITIGATION MEASURES

3.7.13

As mentioned in the EIA report, two assessments (assuming with and without the possible future development) were undertaken to evaluate the traffic noise impacts from the proposed roads and recommended appropriate noise mitigation measures. The project proponent is responsible for the design and construction of these mitigation measures as follows :

Assessment 1 – Worst Case Situation (With possible future development)

Road D1 (With the development to the South of Road D1)

Two sections of cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of 95m and 125m long at the 1m from kerb side of Road D1 adjacent to 65B.
Cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of 85m long behind the footpath of Road D1 adjacent to Area 65B bus-stop;
Cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of 150m long at the 1m from the kerb side of Road D1 adjacent to Area 65D;
Two sections of 5m high vertical barriers of 50m and 40m long behind the footpath of Road D1/L654 adjacent to Area 65 school;
Cantilevered barrier (6m high and 7.5m wide over the carriageway) of 65m long at 2m from the kerb side of Road D1/D10 roundabout;
Section of 115m long deckover between the future development to the south of Road D1 and Area 65D;

5m vertical barriers of 58m long at the central divider of Road D1, west of junction with local road L651;
Cantilevered barrier (5.5m high with 4m cantilever length at 90 degrees to the horizontal) of 58m long behind the footpath, on the north edge of Road D1, west of junction with local road L651;
5m vertical barriers of 36m and 36m long located along the footpath on the north edge and central divider of Road D1, east of the junction with local road L652;
Section of deckover of total 190m long on Road D1 between the future development to the south of Road D1 and Area 67B;
Cantilevered barrier (6m high and 7.5m wide over the carriageway) of 35m long at the kerb side of Road D1 (connecting with the cantilever barrier at Roads P2/D1 roundabout);

Non-sensitive building zones and minimum setback distance from Road D1 are required for Areas 65D and 67B.

Road D8 (With the development to the South of Road D1)

Cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of total 190m long at the kerb side / behind the footpath (near bus bay) of Road D8 southbound for Area 72A school;
Sections of cantilevered barrier (5.5m high with 3.5m cantilever length at 45 degrees to the horizontal) of total 195m long at the kerb side / behind the footpath (near bus bay) of Road D8 near Area 72 residential development.
Cantilevered barrier (5.5m high with 4.5m cantilever length at 45 degrees to the horizontal) of 115m long at the kerb side of Road D8 near Area 72 residential development.

Road D10 (With the development to the South of Road D1)

5m vertical barrier of 90m long at the kerb side of road D10 for the facades of the development to the south of Road D1 near Area 65D;
4m vertical barrier of 95m long at the kerb side of elevated Road D10 westbound near Area 86;
Section of cantilevered barrier (5.5m high with 2m cantilever length at 45 degrees to the horizontal) of 205m at the kerb side of westbound at-grade section and elevated Road D10 leading to the junction of Wan Po Road.

Extended Road P2 (With the development to the South of Road D1)

Two sections of cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 205m and 55m long at kerb side of the Extended Road P2 (at-grade) northbound near Area 72 school;
Cantilevered barrier (5.5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 240m long at kerb side of Extended Road P2 (at-grade) southbound near Area 67;
Cantilevered barrier (6m high and 7.5m wide over the carriageway) of 75m along the Road P2 (at-grade) southbound and part of section of Extended Road P2 (at-grade) / Road D1 roundabout near Area 67;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 40m long at kerb side of Extended Road P2 (at-grade) northbound near Area 72 and south of Road P2 roundabout;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 50m long at the kerb side of the west side of Extended Road P2 (at-grade) southbound near possible future development to the south of Road D1;
5m vertical barrier of 25m long at kerb side of Extended Road P2 (at-grade) southbound near possible future development to the south of Road D1;

Cantilevered barrier (5.5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 155m long at hard shoulder of Extended Road P2 (elevated) northbound near Area 72;

5m vertical barrier of 110m long at hard shoulder of the Extended Road P2 (elevated) southbound near Area 67 schools;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 230m long at hard shoulder of the Extended Road P2 (elevated) southbound near Area 67B and the possible future development to the south of Road D1;
5m vertical barrier of 275m long at central divider of the Extended Road P2 (elevated) near Area 67;
A Y-shape cantilever barrier of 65m long (5m high vertical barrier with 3.5m cantilever lengths on both directions at 45 degrees to the horizontal) at the central divider of the Extended Road P2 (elevated) near the possible future development to the south of Road D1;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 65m long at the hard shoulder of the Extended Road P2 (elevated) northbound near Area 72 and south of the roundabout;
Provision of air conditioning and acoustic insulation for the affected facades of the schools in Area 72.

Assessment 2 – Worst Case Situation (Without possible future development)
Road D1 (Without the development to the South of Road D1)

Cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of 150m long at the 1m from kerb side of Road D1 adjacent to Area 65D;
Two sections of cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of 95m and 125m long at the 1m from kerb side of Road D1 adjacent to 65B.
Cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of 85m long behind the footpath of Road D1 adjacent to Area 65B bus-stop;
Two sections of 5m high vertical barriers of 50m and 40m long behind the footpath of Road D1/L654 adjacent to Area 65C school;
Cantilevered barrier (6m high and 7.5m wide over the carriageway) of 65m long at 2m from the kerb side of Road D1/D10 roundabout;
Cantilevered barriers (5.5m high with 4m cantilever length at 90 degrees to the horizontal) of 108m on Road D1 eastbound adjacent to Area 65D;
Section of semi-enclosure (5.5m high with 11m cantilever length at 90 degrees to the horizontal) of 99m long on Road D1 central divider adjacent to Area 65D;
Semi-enclosure of 58m long located adjacent to Area 66 and local road L651;

Two sections of 5m high vertical barriers of 36m and 36m long, located along the footpath, on the north edge and central divider of Road D1, east of the junction with local road L652;
Section of semi-enclosure (5.5m high with 11m cantilever length at 90 degrees) of total 115m long behind the footpath of Road D1 eastbound adjacent to Area 67B and west of the junction with local road L652;
Section of semi-enclosure (5.5m high with 7m cantilever length at 90 degrees to the horizontal) of 72m long behind the amenity area of Road D1 eastbound adjacent to Area 67B;

Section of semi-enclosure (5.5m high with 10m cantilever length at 90 degrees to the horizontal) of 191m long on the central divider of Road D1 adjacent to Area 67B;
Cantilevered barrier (6m high and 7.5m wide over the carriageway) of 35m long at the kerb side of Road D1 (connecting with the cantilever barrier at Roads P2/D1 roundabout);
Non-sensitive building zones and minimum set-back distances are required for Areas 65D and 67B.

Road D8 (Without the development to the South of Road D1)

Cantilevered barrier (5.5m high with 2.5m cantilever length at 45 degrees to the horizontal) of total 190m long at the kerb side / behind the footpath (near bus bay) of Road D8 southbound for Area 72A school;
Sections of cantilevered barrier (5.5m high with 3.5m cantilever length at 45 degrees to the horizontal) of total 195m long at the kerb side / behind the footpath (near bus bay) of Road D8 near Area 72 residential development.
Cantilevered barrier (5.5m high with 4.5m cantilever length at 45 degrees to the horizontal) of 115m long at the kerb side of Road D8 near Area 72 residential development.

Road D10 (With the development to the South of Road D1)

4m vertical barrier of 95m long at the kerb side of elevated Road D10 westbound near Area 86;
Section of cantilevered barrier (5.5m high with 2m cantilever length at 45 degrees to the horizontal) of 205m at the kerb side of westbound at-grade section and elevated Road D10 leading to the junction of Wan Po Road.

Extended Road P2 (Without the development to the South of Road D1)

Two sections of cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 205m and 55m long at kerb side of the Extended Road P2 (at-grade) northbound near Area 72 school;
Cantilevered barrier (5.5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 240m long at kerb side of Extended Road P2 (at-grade) southbound near Area 67;
Cantilevered barrier (6m high and 7.5m wide over the carriageway) of 75m along the Road P2 (at-grade) southbound and part of section of Extended Road P2 (at-grade) / Road D1 roundabout near Area 67;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 40m long at kerb side of Extended Road P2 (at-grade) northbound near Area 72 and south of Road P2 roundabout;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 50m long at the kerb side of the west side of Extended Road P2 (at-grade) southbound near possible future development to the south of Road D1;
5m vertical barrier of 25m long at kerb side of Extended Road P2 (at-grade) southbound near possible future development to the south of Road D1;

Cantilevered barrier (5.5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 155m long at hard shoulder of Extended Road P2 (elevated) northbound near Area 72;
5m vertical barrier of 110m long at hard shoulder of the Extended Road P2 (elevated) southbound near Area 67 schools;
Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 230m long at hard shoulder of the Extended Road P2 (elevated) southbound near Area 67B and the possible future development to the south of Road D1;
5m vertical barrier of 275m long at central divider of the Extended Road P2 (elevated) near Area 67;
A Y-shape cantilever barrier of 65m long (5m high vertical barrier with 3.5m cantilever lengths on both directions at 45 degrees to the horizontal) at the central divider of the Extended Road P2 (elevated) near the possible future development to the south of Road D1;

Cantilevered barrier (5m high with 3.5m cantilever length at 45 degrees to the horizontal) of 65m long at the hard shoulder of the Extended Road P2 (elevated) northbound near Area 72 and south of the roundabout;
Provision of air conditioning and acoustic insulation for the affected facades of the schools in Area 72.

3.7.14

The design and construction of the mitigation measures for Road P2 south to the roundabout will be carried during Future Road P2 construction.

3.7.15

The locations of the proposed noise barriers and cross-section of the noise barriers are shown in Figures C1 to C22. The implementation schedule for the mitigation measures is presented in Appendix C2.

EVENT AND ACTION PLAN

3.7.16

The measured / monitored noise levels shall be compared with the predicted results and the predicted traffic flow conditions (calculated noise levels based on concurrent traffic census obtained). In case discrepancies are observed, explanation should be given to justify the discrepancies.