Cause of Impact
The potential source of noise impact during construction phase would mainly be the use of powered mechanical equipment (PME) for various construction activities. Ground-borne noise impact could arise from hydraulic breakers, pipe pile rigs and drilling rigs for tunneling works.
Air-borne noise impact would arise from ventilation facilities and cooling tower. Ground-borne noise impact would arise from trains running on tracks inside tunnels.
In order to minimize ground-borne noise impacts during the construction phase, the following remedies will be applied:
- Use of quiet PME;
- Using noise barriers or enclosures;
- Using acoustic fabric for piling and drilling machines;
- Using silencers and mufflers for ventilation fans;
- Positioning and orientating noisy PME away from sensitive receivers as far as possible; and
- Shutting down or throttling down noisy PME to minimum between works periods.
In order to minimise air-borne and ground-borne noise impacts during the operation phase, the following remedies will be applied:
- Orienting fixed plant / louvers away from sensitive receivers where possible;
- Adopting silencers, acoustic louvers and acoustic enclosures where necessary;
- Choosing quieter fixed plant and ensuring the maximum permissible sound levels can be met; and
- Installing vibration mitigating trackform.
Results indicate that even with implementation of mitigation measures to reduce the construction noise impacts, there would still be exceedances of the noise criteria stipulated in the EIAO-TM at some of the sensitive receiver (click here to see the results). All remedies described above shall be exhausted to keep the residual impacts to a minimum.
For operation phase, the noise levels from fixed plant and railway operation would fully comply with the noise criteria stipulated in the EIAO-TM and Noise Control Ordinance.