3.1.1 In this section, the requirements, methodology, equipment, monitoring locations, criteria and protocols for the monitoring and audit of noise impacts during the construction and operation phase of the Project are presented.
3.1.2 Construction noise impact and traffic noise impact from this Project are predicted at the identified NSRs. Noise mitigation measures would be required to reduce noise levels to the stipulated standard. A noise monitoring programme should be undertaken to confirm such mitigation measures would be implemented properly.
3.1.3 According to the EIA, road traffic noise levels should be monitored at representative NSRs, which are in the vicinity of the recommended direct mitigation measures, during the first year after road opening. The purpose of the monitoring is to ascertain that the recommended mitigation measures are effective in reducing the noise levels.
3.1.4 For fixed noise sources, the Contractor should also carry out a noise commissioning test for all fixed noise sources before operation of the Project, in order to ensure compliance of the operation airborne noise levels with the TM’s stipulated noise standard.
3.2.1 The construction noise levels should be measured in terms of the A-weighted equivalent continuous sound pressure level Leq. Leq(30-min) should be used as the monitoring parameter for the time period between 0700 and 1900 hours on normal weekdays.
3.2.2 The ET should also carry out monitoring of road traffic noise after the works under Contract are completed and put into operation. The road traffic noise during operation of the Project should be measured in terms of the A-weighted equivalent of L10 (1-hr). During the traffic noise measurement, traffic count should also be undertaken concurrently.
3.2.3 Supplementary information for data auditing and statistical results such as L10 and L90 should also be obtained for reference. Sample noise field data sheets are shown in Appendix B of this Manual for reference. The ET Leader may modify the data record sheet for this EM&A programme but the format of which should be agreed by the IEC.
3.3.1 As referred to in the Technical Memorandum (TM) issued under the 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 shall be accepted as valid only if the calibration level from before and after the noise measurement agree to within 1.0 dB.
3.3.2 Noise measurements shall not be made in fog, rain, wind with a steady speed exceeding 5m/s or wind with gusts exceeding 10m/s. The wind speed shall be checked with a portable wind speed meter capable of measuring the wind speed in m/s.
3.3.3 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. The equipment installation location shall be proposed by the ET Leader and agreed with the ER and EPD in consultation with the IEC.
Construction Phase
3.4.1 Figures 3.1 show the noise monitoring locations for the construction phase. The proposed noise monitoring locations are summarised in Table 3.1 below.
Table 3.1 Proposed Construction Noise Monitoring Stations
|
Station |
NSR ID Reference (Based on EIA Report) |
Location |
|
CM1 |
N1102 |
Nga Lai House, Yau Lai Estate Phase 1, Yau Tong |
|
CM2 |
N1204 |
Bik Lai House, Yau Lai Estate Phase 1, Yau Tong |
|
CM3 |
||
|
CM4 |
N3101a |
Tin Hau Temple, Cha Kwo Ling |
|
CM5 |
N4101 |
CCC Kei Faat Primary School, Yau Tong |
|
CM6 |
N5012 |
Tower 1, Ocean Shores, Tseung Kwan O |
|
CM7 |
N5072 |
Tower 7, Ocean Shores, Tseung Kwan O |
|
CM8 |
N7603 |
Tower 6, Park Central, Tseung Kwan O |
3.4.2 The status and locations of noise sensitive receivers may change after issuing this Manual. If such cases exist, the ET shall propose updated monitoring locations and seek approval from the ER and IEC and agreement from EPD of the proposal.
3.4.3 When alternative monitoring locations are proposed, the monitoring locations shall be chosen based on the following criteria:
(i) at locations close to the major site activities which are likely to have noise impacts;
(ii) close to the noise sensitive receivers; and
(iii) for monitoring locations located in the vicinity of the sensitive receivers, care shall be taken to cause minimal disturbance to the occupants during monitoring.
3.4.4 The construction noise monitoring station shall normally be at a point 1 m from the exterior of the sensitive receivers building façade and be a position 1.2m above the ground. If there is a problem with access to the normal monitoring position, an alternative position shall 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 ER and IC(E) 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.
Operation Phase
3.4.5 The traffic noise monitoring locations are shown in Figure 3.2 and are summarised in Table 3.2. The status and locations of noise sensitive receivers may change after this Manual is issued. If such cases exist, the ET Leader should propose alternative monitoring locations and seek approval from the IEC and agreement from EPD of the proposal.
Table 3.2 Proposed Traffic Noise Monitoring Stations
|
Station |
NSR ID Reference (Based on EIA Report) |
Location |
|
OM1 |
N1102 |
Nga Lai House, Yau Lai Estate Phase 1, Yau Tong |
|
OM2 |
N1204 |
Bik Lai House, Yau Lai Estate Phase 1, Yau Tong |
|
OM3 |
||
|
OM4 |
||
|
OM5 |
||
|
OM6 |
||
|
OM7 |
3.4.6 When alternative monitoring locations are proposed, the monitoring locations should be chosen based on the following criteria:
(i) They should be at NSRs in the vicinity of recommended direct technical remedies; preferably, there should be one representative monitoring locations near each types of noise screening element (i.e. vertical barrier, cantilevered barrier and enclosure);
(ii) One high floor and one medium floor monitoring points should be chosen at each location as far as possible; and
(iii) Selected monitoring locations should enable monitoring to be done twice within one year after implementation of the mitigation measures during operation of the proposed road.
3.4.7 The operational noise monitoring should be carried out at the distance of 1m from the openable window and 1.2m above the floor level of the noise sensitive receivers identified. The ET should agree with the IEC on any necessary corrections to be adopted.
Construction Phase
3.5.1 Baseline noise monitoring shall be carried out daily in all of the identified monitoring stations for at least 2 weeks prior to the commissioning of the construction works. A schedule of the baseline monitoring shall be submitted to the ER for approval before the monitoring starts.
3.5.2 During the baseline monitoring, there shall not be any construction activities in the vicinity of the monitoring stations.
3.5.3 In exceptional cases, when insufficient baseline monitoring data or questionable results are obtained, the ET leader shall liaise with EPD and in consultation with ER and the IEC to agree on an appropriate set of data to be used as a baseline reference.
Operation Phase
3.5.4 No baseline operation noise monitoring is generally required.
Construction Phase
3.6.1 Noise monitoring should be carried out at the designated monitoring station when there are Project-related construction activities being undertaken within a radius of 300m from the monitoring stations. The monitoring frequency should depend on the scale of the construction activities. An initial guide on the monitoring is to obtain one set of 30-minute measurement at each station between 0700 and 1900 hours on normal weekdays at a frequency of once a week when construction activities are underway.
3.6.2 If construction works are extended to include works during the hours of 1900 - 0700, additional weekly impact monitoring shall be carried out during evening and night-time works. Applicable permits under NCO shall be obtained by the Contractor.
3.6.3 In case of non-compliance with the construction noise criteria, more frequent monitoring, as specified in the Action Plan in Table 3.4 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.
Operation Phase
3.6.4 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:
(i) one set of measurements at the morning traffic peak hour on normal weekdays;
(ii) one set of measurement at the evening traffic peak hour on normal weekdays;
(iii) a concurrent census of traffic flow and percentage heavy vehicles shall be conducted for the far-side and near-side of the road and the existing road network in the vicinity of each measurement points;
(iv) average vehicle speed estimated for far-side and near-side of the road and the existing road network in the vicinity of each measuring points; and
(v) the two sets of monitoring data shall be obtained within the first year of operation.
3.6.5 Measured noise levels shall be compared with the predicted noise levels by applying appropriate conversion corrections to allow for the traffic conditions at the time of measurement. Appendix B shows a sample data record sheet for traffic noise monitoring.
Construction Phase
3.7.1 The Action and Limit levels for construction noise are defined in Table 3.3. Should non-compliance of the criteria occur, action in accordance with the Action Plan in Table 3.4 shall be carried out.
Table 3.3 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)* |
Notes:
If works are to be carried out during restricted hours, the conditions stipulated in the Construction Noise Permit (CNP) issued by the Noise Control Authority have to be followed.
* 70 dB(A) and 65 dB(A) for schools during normal teaching periods and school examination periods, respectively.
Table 3.4 Event and Action Plan for Construction Noise
|
EVENT |
ACTION |
|||
|
|
ET |
IEC |
ER |
CONTRACTOR |
|
Action Level |
1. Notify IEC and Contractor; 2. Carry out investigation; 3. Report the results of investigation to the IEC, ER and Contractor; 4. Discuss with the Contractor and formulate remedial measures; 5. Increase monitoring frequency to check mitigation effectiveness. |
1. Review the analysed results submitted by the ET; 2. Review the proposed remedial measures by the Contractor and advise the ER accordingly; 3. Supervise the implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. Require Contractor to propose remedial measures for the analysed noise problem; 4. Ensure remedial measures are properly implemented.
|
1. Submit noise mitigation proposals to IEC; 2. Implement noise mitigation proposals. |
|
Limit Level |
1. Identify source; 2. Inform IEC, ER, EPD and Contractor; 3. Repeat measurements to confirm findings; 4. Increase monitoring frequency; 5. Carry out analysis of Contractor’s working procedures to determine possible mitigation to be implemented; 6. Inform IEC, ER and EPD the causes and actions taken for the exceedances; 7. Assess 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 Contractors remedial actions whenever necessary to assure their effectiveness and advise the ER accordingly; 3. Supervise the implementation of remedial measures. |
1. Confirm receipt of notification of failure in writing; 2. Notify Contractor; 3. Require Contractor to propose remedial measures for the analysed noise problem; 4. Ensure remedial measures properly implemented; 5. 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. |
1. Take immediate action to avoid further exceedance; 2. Submit proposals for remedial actions to IEC within 3 working days of notification; 3. Implement the agreed proposals; 4. Resubmit proposals if problem still not under control; 5. Stop the relevant portion of works as determined by the ER until the exceedance is abated. |
Operation Phase
3.7.2 For the traffic noise, 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 shall be given to justify the discrepancies.
Construction Phase
3.8.1 To alleviate the construction noise impact on the affected NSRs, movable noise barriers and acoustic mats are proposed to be provided for particular items of plant and construction works. It is anticipated that a movable noise barrier with a cantilevered upper portion located within 5m from any static or mobile plant can provide 5 dB(A) noise reduction for mobile plant and 10 dB(A) noise reduction for static plant. The barrier material shall have a surface mass of not less than 14 kg/m2 on skid footing with 25mm thick internal sound absorptive lining to achieve the maximum screening effect.
3.8.2 In addition, the good site practices listed below should be adopted by all the Contractors to further ameliorate the noise impacts.
• Only well-maintained plant should be operated on-site and plant should be serviced regularly during the construction program.
• Silencers or mufflers on construction equipment should be utilised and should be properly maintained during the construction program.
• Mobile plant, if any, should be sited as far away from NSRs as possible.
• Machines and plant (such as trucks) that may be in intermittent use should be shut down between works periods or should be throttled down to a minimum.
• Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from the nearby NSRs.
• Material stockpiles and other structures should be effectively utilised, wherever practicable, in screening noise from on-site construction activities.
3.8.3 If the above measures are not sufficient to restore the construction noise quality to acceptable levels upon the advice of ET Leader, the Contractor shall liaise with the ET Leader to identify further mitigation measures. They shall be proposed to ER for approval, and the contractor shall then implement these additional mitigation measures.
3.8.4 The implementation schedule for the recommended mitigation measures is presented in Appendix C.
Operation Phase
3.8.5 The following direct mitigation measures for existing NSRs, as shown in Figure 3.3 and summarized below (with total length of the mitigation measures rounded off to the nearest 10m), have been proposed in the EIA.
· VB4-1: about 10m of 4m High Vertical Noise Barrier on Cha Kwo Ling Road (shown in Figure 4.6 (Sheet 1 of 4));
· VB4-2: about 40m of 4m High Vertical Noise Barrier on Cha Kwo Ling Road (shown in Figure 4.6 (Sheet 1 of 4));
· CT1: about 100m of 6m High Cantilever Noise Barrier with 4.2m Cantilever (at 45 °) on Cha Kwo Ling Road (shown in Figure 4.6 (Sheet 1 of 4));
· CT2: about 80m of 6m High Cantilever Noise Barrier with 3.7m Cantilever (at 90°) on road EHC2 (shown in Figure 4.6 (Sheet 2 of 4));
· FE1: about 400m Landscape deck provided on the entire extent of the Main line (Cha Kwo Ling Side) (shown in Figure 4.6 (Sheet 2 of 4));
· FE2: about 130m of Full-enclosure provided on road S2 (shown in Figure 4.6 (Sheet 2 of 4));
· FE3: about 120m of Full-enclosure provided on road EHC4 (shown in Figure 4.6 (Sheet 2 of 4));
· FE4: about 200m of Landscape Deck provided on road P2 (shown in Figure 4.6 (Sheet 4 of 4));
· SE1: about 260m of Semi-enclosure provided on road EHC2 (shown in Figure 4.6 (Sheet 2 of 4));
· SE2: about 180m of Semi-enclosure provided on road S2 (shown in Figure 4.6 (Sheet 2 of 4));
· SE3: about 30m of Semi-enclosure provided on road EHC4 (shown in Figure 4.6 (Sheet 2 of 4));
· VB5-1: about 130m of 5m High Vertical Noise Barrier provided at road EHC4 (shown in Figure 4.6 (Sheet 2 of 4));
· VB5-2: about 50m of 5m High Vertical Noise Barrier provided at road EHC4 (shown in Figure 4.6 (Sheet 2 of 4));
· VB5-3: about 80m of 5m High Vertical Noise Barrier provided at road EHC1 (shown in Figure 4.6 (Sheet 2 of 4));
· VB5-4: about 70m of 5m High Vertical Noise Barrier provided at road EHC1 (shown in Figure 4.6 (Sheet 2 of 4));
· VB5-5: about 170m of 5m High Vertical Noise Barrier provided at road S3 (shown in Figure 4.6 (Sheet 2 of 4));
· VB5-6: about 180m of 5m High Vertical Noise Barrier provided at road S1 (shown in Figure 4.6 (Sheet 2 of 4));
· LNS1: about 190m of Low Noise Surfacing on North and South Bound P2 Road (shown in Figure 4.6 (Sheet 3 of 4));
· LNS2: about 240m of Low Noise Surfacing on East and West Bound Po Yap Road (shown in Figure 4.6 (Sheet 3 of 4)); and
· LNS3: about 200m of Low Noise Surfacing on East and West Bound Po Yap Road (shown in Figure 4.6 (Sheet 3 of 4)).
3.8.6 The following direct mitigation measures, as shown in Figure 3.4, have been proposed to protect planned NSRs. These noise mitigation measures would only be required to be constructed before the occupation of the planned NSRs:
· FE5: about 80m of Full-enclosure on road EHC4 (shown in Figure 4.7a)
3.8.7 The implementation schedule for the recommended mitigation measures is presented in Appendix C.