5            Noise

 5.1              Introduction

 5.1.1.1                  During construction phase for the Proposed Helipad, powered mechanical equipment (PME) used in helipad construction would be the primary noise source.  Key construction activities would be building the steel framework, helipad structure, safety walkway, access ramp and the proposed noise mitigation measures (i.e. noise barriers and noise reducers).

 5.1.1.2                  Potential construction noise impact has been assessed at the representative Noise Sensitive Receiver (NSR) in the EIA report.  The calculation show that there is no noise exceedance of the relevant noise criterion.

 5.1.1.3                  During operation phase of the Project, the main noise source would be from helicopter operation associated with the Proposed Helipad.  Based on the operation mode of the helicopter from approach to lift-off, setback of helipad, proposed quiet approach/ departure procedures, implementation of noise barriers and proposed flight sectors, there would be no noise exceedance of the relevant noise criterion at the representative NSRs.  The Proposed Helipad is solely for emergency use where the anticipated usage is less than once per day.  Operational noise monitoring is impracticable as there are no scheduled helicopter flights and so noise monitoring during operation phase is not necessary.

 5.2             Environmental Audit

 5.2.1.1                  The EIA report has not anticipated adverse construction noise impact from the Project.  Therefore, construction phase noise monitoring is not necessary.  However, regular site inspection during construction phase at least once per week is recommended to ensure the ET Leader has effectively implemented good working practices to minimise construction noise as far as possible, including:

 l   Submit details of the working method, equipment and noise mitigation measures intended for use to the ER before works commence;

 l   Devising and executing works methods to minimise noise impact on sensitive uses, and providing experienced personnel with suitable training to ensure that such works methods are properly implemented;

 l   Locating noisy equipment and noisy activities as far from NSRs as is practical;

 l   Turn off any unused equipment;

 l   Powered mechanical equipment should be kept to a minimum and the parallel use of noisy equipment / machinery should be avoided;

 l   Regular maintenance of all plant and equipment; and

 5.2.1.2                   The Contractor shall observe and comply with the relevant statutory requirements and guidelines.

 5.2.1.3                  Regular audits and site inspections at least once per week should be carried out during the construction phase by the ET to ensure that the recommended mitigation measures are properly implemented by the Contractor.

 5.2.1.4                  If the noise levels exceed the relevant noise criteria after adopting the above measures upon ET Leader’s advices, the Contractor shall liaise with the ET Leader on some other mitigation measures, propose them to ER and IEC for approval and carry out the mitigation measures after approval.

 5.3             Mitigation Measures

 5.3.1.1                  Based on the assessment results, no adverse noise impact is anticipated during operation phase.  The relevant noise mitigation measures have been recommended in the EIA report to minimise the helicopter noise impact.

 5.3.1.2                  The following mitigation measures have been implemented for the Project to minimise potential noise disturbance upon NSRs during operation phase:

Procurement of New GFS Helicopters

 5.3.1.3                  The existing GFS’s helicopter fleet will be replaced by seven medium-sized single-model helicopters (Airbus H175) which provide a quieter flight in general.

Setback of Helipad

 5.3.1.4                  Relocation of the proposed helipad to the north-eastern side of the rooftop of the New Block of QMH to reduce the noise impact and direct line of sight at NSRs.  The separation distances between the helipad and NSRs is also maximised.

Screening by Noise Barriers

 5.3.1.5                  Installation of noise barriers at the rooftop of the New Block of the QMH to provide noise screening to the Proposed Helipad during hovering, touchdown, lift-off and idling on the helipad.  In addition, use of noise reducers should also be considered to further alleviate noise impact.

Quiet Approaching/ Departure Procedures

 5.3.1.6                  A quiet approaching and departure technique would be adopted.  This includes a steeper glide slope and larger take-off angle during approaching and departure to increase the distance between the NSR and the helicopter flight profile.  The approaching and departure angles have been increased from 4.6 degrees to 10 degrees.  In addition, helicopter operations are proposed to be in a one-way direction within the selected flight sectors in order to minimise the overall exposure of NSRs to helicopter noise.  In other words, the arrival and departure flight shall be from north to south and vice versa.  Using the same flight path for approaching and departure of each operation is not preferred.

 5.4             Event and Action Plan

 5.4.1                  Construction Noise

 5.4.1.1                  Noise Standards for daytime construction activities are specified under EIAO-TM.  The Action and Limit (AL) levels for construction noise are presented in Table 5.1.  In the event of non-compliance, action in accordance with the Event and Action Plan in shall be implemented.

Table 5.1    Action and Limit Level for Construction Noise

Time Period

Action

Limit

0700 – 1900 hours in normal weekdays

When one valid documented complaint is received.

75 dB(A)

Note: If there will be works carried out during restricted hours, the conditions stipulated in the Construction Noise Permit (CNP) issued by the Noise Control Authority have to be followed.

Table 5.2      Event and Action Plan for Construction Noise

Event

Action

ET

IEC

ER

Contractor

Action Level Exceedance

 1.   Notify ER, IEC and Contractor;

 2.     Carry out investigation;

 3.     Report the results of the investigation to the IEC, ER and Contractor; and

 4.     Discuss with the IEC and Contractor on remedial measures required.

 1.   Review the investigation results submitted by the ET;

 2.   Review the proposed remedial measures the contractor and advise the ER accordingly; and

 3.  Advise the ER on the effectiveness of the proposed remedial measures.

 1.  Confirm receipt of notification of failure in writing;

 2.   Notify Contractor;

 3.   In consolidation with the IEC, agree with the Contractor on the remedial measures to be implemented; and

 4.   Supervise the implementation of remedial measures.

 1.   Submit noise mitigation proposals to IEC and ER; and

 2.   Implement noise mitigation proposals.

Limit Level Exceedance

 1. Inform IEC,ER, Contractor and EPD

 2.  Repeat measurements to confirm findings;

 3.  Increase monitoring frequency;

 4.  Identify source and investigate the cause of exceedance;

 5.  Carry out analysis of Contractor’s working procedure

 6.  Discuss with IEC, Contractor and ER on remedial measures required;

 7.  Assess the effectiveness of Contractor’s remedial actions and keep IEC, EPD and ER informed of the results;

 8. If exceedance stops, cease additional monitoring.

 1. Discuss amongst ER, ET and Contractor on the potential remedial actions;

 2. Review Contractor’s remedial actions whenever necessary to assure their effectiveness and advise the ER accordingly.

 1. Confirm receipt of notification of failure in writing;

 2.  Notify Contractor;

 3. In consolidation with the IEC, agree with the Contractor on the remedial measures to be implemented;

 4. Supervise the implementation of remedial measures;

 5. If exceedance continues, consider stopping the Contractor to continue working on that portion of work which causes the exceedance until the exceedance is abated.

 1. Take immediate action to avoid further exceedance;

 2. Submit proposal for remedial actions to  IEC and ER within 3 working days of notification;

 3. Submit further proposal if problem is still not under control;

 4.  Stop the relevant portion of works as instructed by the ER until the exceedance is abated.

 5.4.2                  Helicopter Noise

 5.4.2.1                  Based on the assessment results, mitigation measures as listed in Section 5.3 are recommended for the proposed helipad to reduce the potential noise impact from helicopter operation.  These include setback of helipad, quiet approach/ departure procedures and installation of noise barrier.  With the implementation of these measures, there will be no exceedance of the relevant noise criteria at the representative NSRs.

 5.4.2.2                  The proposed helipad is solely for emergency use only.  There are no scheduled flights and the anticipated frequency of usage is less than once per day.  As such, operational noise monitoring, in particular real-time monitoring, is not considered necessary.

 5.4.2.3                  Should the need arise, the local community may lodge noise complaints with the relevant authority.  Upon receipt of complaints from the public or any concerned parties, Hospital Authority (HA) shall undertake the following procedures:

 1)     The complaint shall be recorded in a complaint database and reviewed by HA and GFS;

 2)     Investigate the complaint and determine its validity as well as the source of the problem by HA and Government Flying Services (GFS);

 3)     Identify mitigation measures by HA and GFS; and

 4)     Report the findings and follow-up actions to the complainant or the concerned parties by HA.