12.               Environmental monitoring and audit

Introduction

12.1            To ascertain and verify the assumptions implicit to and accuracy of EIA study predictions, an EM&A programme would be needed.  This section further elaborates the requirements of EM&A for the construction and operation of the Project, based on the assessment results of various issues. 

12.2            The following sections summarize the recommended EM&A requirements.  Details of the EM&A programme are presented in a stand-alone EM&A Manual released separately. 

Airborne Noise Impact

Construction Phase

12.3            Construction noise impacts from this Project would be expected at NSRs identified in this EIA.  Appropriate mitigation measures would be required in order to alleviate the impacts to meet the EIAO-TM criteria.  Noise monitoring during construction phase needs to be carried out to ensure that such mitigation measures would be implemented properly.

12.4            The construction activities will be carried out during daytime (between 0700 and 1900 hours).  If there is construction work undertaken in restricted hours, measurements will also be carried out for the following periods:

·        Between 1900 and 2300 hours;

·        Between 2300 and 0700 hours of next day; and

·        Between 0700 and 1900 hours on Sunday or public holidays

12.5            Noise monitoring should be carried out at all the designated monitoring stations, and measurement should be undertaken at a minimum logging interval of 30 minutes for daytime and 15 minutes (as three consecutive Leq, (5 minutes) readings) for evening time and night time.  The Leq, L10 and L90 should be recorded at the specified interval.  Type 1 sound level meters, which comply with the International Electrochemical Commission (Publications 651:1979 and 804:1985), must be used for carrying out the noise measurement.

12.6            Ad hoc noise monitoring should also be carried out if necessary.  Prior to the commencement of the Project, baseline monitoring should be measured for a continuous period of at least 14 consecutive days at a minimum logging interval of 30 minutes for daytime and 15 minutes (as three consecutive Leq, (5 minutes) readings) for evening time and night time. The Leq, L10 and L90 should be recorded at the specified interval.  Details of the EM&A programme are provided in a stand-alone EM&A Manual. 

Operation Phase

12.7            Prior to the operation phase of the Project, a commissioning test should be conducted by the Contractor to ensure compliance of the operational airborne noise levels with the EIAO-TM noise criteria.  The testing results should be checked and verified by the Environmental Team and Independent Environmental Checker respectively. 

Groundborne Noise Impact

Construction Phase

12.8            Monitoring of ground-borne noise from tunnel boring should be conducted.  The recording of data should proceed whenever the TBM is in operation.  Details of the monitoring requirements are presented in the EM&A Manual.


Operation Phase

12.9            Trackform mitigation is recommended in this EIA. In order to ensure compliance of the operational ground-borne noise criteria, a commissioning test will be included in the Contract document.  More frequent rail and train maintenance, and adjustment of speed profile at critical locations will be able to further reduce the ground-borne noise impacts as a contingency measures. 

12.10        The currently proposed Type 1a resilient baseplates can be replaced by Type 1b or Type 2 where practicable and necessary to accomplish a further 3-6dB(A) noise reduction as a contingency measure (Type 1b and Type 2 baseplates would not be suitable at turnouts due to maintenance and safety concerns).  Changing of the tunnel dimensions would not be required if these contingency measures have to be in place.  Further measurements would be conducted to check the accuracy of the noise prediction after the tunnel construction where necessary. 

Landscape and Visual Impact

Construction Phase

12.11        The landscape and visual mitigation measures should be incorporated in the detailed design, so as to ensure the effectiveness of the mitigation measures described in Table 5.4, Section 5 of EIA report.  Any changes to the mitigation measures that may be recommended to match the baseline review result or to match the ongoing EM&A should also be incorporated in the detailed design.

12.12        The design, implementation and maintenance of mitigation measures should be checked regularly to ensure that they are fully realised and compliance with the intended aims of the measures.  Any potential conflicts among the proposed mitigation measures, the project works, and operational requirements should also be identified and resolved early.  The proposed mitigation measures should always be given priority.

12.13        Landscape proposals and details of architectural design, chromatic treatment and visual and landscape mitigation measures for all above ground structures, including station entrances and vent shafts, to demonstrate that they would be sensibly designed in a manner that responds to the existing urban context will be submitted to Planning Department for review.  The proposals should be submitted 2 months before the commencement of project construction.

12.14        A landscape specialist with substantial construction site experience should be responsible for supervising the landscape works during the Construction Phase to ensure these mitigation measures will be monitored, and form part of the ongoing site audit programme.

12.15        The implementation of landscape construction works and maintenance operations during the subsequent 12 month Establishment Period must be supervised by landscape specialist. The employment of a landscape specialist for monitoring the tree protection measures is cited in the EIA as a mitigation measure, and their involvement should be monitored.

12.16        The extent of the agreed works areas should be regularly checked during the construction phase.  Any trespass by the Contractor outside the limit of the works, including any damage to existing trees shall be reported to the appropriate authorities.       

12.17        The progress of the engineering works should be regularly reviewed on site to identify the earliest practical opportunities for the soft landscape works to be undertaken.

Operational Phase

12.18        All landscape and visual mitigation measures should be monitored regularly during the first year of the Operational Phase.

Cultural Heritage Impact                                                                                    

12.19        Monitoring of vibration levels from tunnel formation along WIL by drill and blast would be required at the historic buildings.  Blasting should be monitored at either one or two locations per blast location, and all blasting should be monitored.  Monitoring should occur at the designated sensitive receiver for as long as the blasting is within 100m plan of the sensitive receiver, or until another receiver is closer.  Details on the requirements on the selection of measurement locations, equipment, data monitoring, tabulation of data, and reporting and action are presented in Section 6.50-6.59.

12.20        Archaeological watching brief would be required at the directly impacted areas identified to be of archaeological potential which are listed in Section 6.28. The watching brief should be conducted by a qualified and licensed archaeologist to monitor the excavation works during the construction phase in the identified locations.  Details of the frequency of inspection shall be provided to AMO for review and comment once the detailed construction programme has been finalized.

12.21        EM&A requirements for landscape and visual impacts would also be applicable for the protection of heritage resources.

Waste Management Implications

12.22        Waste management will be the contractor’s responsibility to ensure that all wastes produced during the construction of the Project are handled, stored and disposed of in accordance with the recommended good waste management practices and EPD’s regulations and requirements.  The mitigation measures recommended in Section 7 should form the basis of the site Waste Management Plan to be developed by the Contractor at the construction stage.

12.23        It is recommended that the waste arisings generated during the construction activities should be audited periodically by ET to determine if wastes are being managed in accordance with approved procedures and the site Waste Management Plan.  The audits should look at all aspects of waste management including waste generation, storage, recycling, transport and disposal.  An appropriate audit programme would be to undertake a first audit near the commencement of the construction works, and then to audit on a quarterly basis thereafter.  In addition, the routine site inspections should check the implementation of the recommended good site practices and other waste management mitigation measures.

Land Contamination

12.24        In accordance with the findings of the EIA study, most of the potential contaminated sites identified at the site inspection are not likely to pose any significant and direct impacts to the Project, therefore, no mitigation measure is considered necessary.

Water Quality Impact

Construction Phase

12.25        The water quality assessment concluded that the identified water quality impacts during the construction phase could be minimized by implementing the recommended mitigation measures to control site runoff and drainage from surface works areas and to treat tunnelling wastewater prior to discharge.  No unacceptable residual water quality impact was expected.  Effluent discharge from the works areas to the public drain would be required to comply with the terms and conditions of a discharge licence issued by EPD under the WPCO.  As a precautionary measure against potential impact on tree walls at Forbes Street due to groundwater drawdown resulted from tunnelling, monitoring of groundwater level will be conducted on a weekly basis during construction phase of the Project.  The monitoring of marine water quality during the land-based construction activities for the Project is therefore not considered warranted.  However, it is recommended that regular audit of the implementation of the recommended mitigation measures at the works area be undertaken during construction phase to ensure the recommended mitigation measures are properly implemented.


Operation Phase

12.26        Discharges of sewage and wastewater effluent from the stations to the foul sewer would be required to comply with the terms and conditions of a discharge licence issued by EPD under the WPCO.  Additional water quality impact monitoring during the operational phase would not be necessary.

Air Quality Impact (Construction Stage)

12.27        With the implementation of the dust suppression measures stipulated in the Air Pollution Control (Construction Dust) Regulation, good site practices and proposed mitigation measures, potential construction dust impact would comply with the HKAQO.  Dust monitoring requirements are recommended in the EM&A Manual to ensure the efficacy of the control measures.  Details of the EM&A programme are provided in a stand-alone EM&A Manual.

Hazard to Life

12.28        Blasting activities regarding storage, use and transport of explosives should be supervised and audited by competent site staff to ensure strict compliance with the blasting permit conditions.