8                   Environmental monitoring and Audit (EM&A) requirements

8.1                 Introduction

8.1.1           This section further elaborates the requirements of environmental monitoring and audit (EM&A) for the construction and operation phases of the Project, based on the assessment results of the various environmental issues.  The objectives of carrying out EM&A for the Project include the following:

·      to provide a database against which any short or long term environmental impacts of the Project can be determined;

·      to provide an early indication should any of the environmental control measures or practices fail to achieve the acceptable standards;

·      to monitor the performance of the Project and the effectiveness of mitigation measures;

·      to verify the environmental impacts predicted in the EIA Study;

·      to determine project compliance with regulatory requirements, standards and government policies;

·      to provide a plan for  remedial action if unexpected problems or unacceptable impacts arise; and

·      to provide data to enable an environmental audit.

8.1.2           The following sections summarise the recommended EM&A requirements for the various environmental impacts of this Project.  Details of the specific requirements are provided in a stand-alone EM&A Manual prepared according to the findings and recommendations of this EIA Study.

8.2                 Air Quality Impact

8.2.1           Potential dust impacts would be generated from site clearance, excavation, materials handling, and wind erosion.  The construction works are controlled by the Air Pollution Control (Construction Dust) Regulation, and mitigation measures such as watering are required under the regulation to limit its dust emission.   Dust monitoring requirements have been recommended in the EM&A Manual to ensure that the mitigation measures are properly implemented and are effective.

8.2.2           The predicted air quality during the TPSTW operation at the ASRs complies with the criteria.  It is recommended that H2S monitoring should be carried out during the operation phase to ensure that the odour criteria are satisfied at the ASRs.  Details of the monitoring programme are presented in the EM&A Manual.

8.3                 Water Quality Impact

8.3.1           The model predicted that the Project would not have adverse impact on Victoria Harbour.  With upgrading of the Tai Po and Sha Tin effluent pumping stations and associated facilities, the Project would not cause any adverse impact on the water quality of Tolo Harbour during normal operation.  The need for a comprehensive post project monitoring programme in Victoria Harbour would depend on the prevailing environmental conditions at the time near commissioning of the Project.  Details of the programme will be subject to EPD’s endorsement.

8.3.2           With upgrading of the Tai Po and Sha Tin effluent pumping stations and associated facilities, the Project would not cause any adverse impact on the water quality of Tolo Harbour under normal operation.  Nevertheless, a 3-month water quality monitoring will be carried out after full commissioning of the Project to collect water quality information at the WSD seawater intakes at Tai Po and Shatin during normal operation.

8.3.3           Marine water quality monitoring is also recommended in Tolo Harbour for emergency discharge due to plant failure and THEES maintenance periods during the construction phase and a 3 years post commissioning period.  Marine water quality parameters such as SS, BOD5, E.coli, chlorophyll-a, TIN and NH3-N should be monitored at six selected monitoring stations, including the WSD seawater intakes at Tai Po and Shatin.  A six-month baseline monitoring programme covering both dry and wet seasons is proposed at a frequency of once per month to establish the baseline water quality conditions at these monitoring points.  In case of emergency discharge, daily marine water monitoring should be conducted throughout the whole discharge period until the normal water quality resumes or at least 1 week after the normal plant operation is restored.  For THEES maintenance, marine water quality data should be collected throughout the whole discharge period at a frequency of 3 times per week until the baseline water quality is restored or at least 4 weeks after the end of maintenance period.

8.3.4           Monitoring of effluent qualityis also recommended. Parameters to be monitored include pH, BOD5, SS, TIN, NH3-N and E.coli.

8.3.5           Details of the water quality monitoring requirements are presented in the EM&A Manual.


8.4                 Waste Management Implications

8.4.1           During construction stage, waste management will be the contractor’s responsibility. The Contractor must  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 5 should form the basis of a Waste Management Plan to be developed by the Contractor at the construction stage.

8.4.2           It is recommended that the waste arisings generated during the construction activities should be checked against the Waste Management Plan.  In addition, the routine site inspections should check the implementation of the recommended good site practices and other waste management mitigation measures.


8.5                 Landfill Gas Hazard

8.5.1        A landfill restoration monitoring programme, conducted on a monthly basis, is part of the Restoration Contract for Shuen Wan Landfill. However, monitoring for landfill gas within the proposed project site boundary is still considered necessary during the construction and operational phase of the TPSTW in order to identify any migration between the landfill and the site and to ensure the safety of the Contractor’s personnel.

8.5.2        During the construction phase, portable gas detectors shall be used regularly to check the levels of methane, carbon dioxide and oxygen in depressions, trenches, and excavations. The regular monitoring shall be undertaken at least for the beginning of each half working day (i.e. morning and afternoon) for the entire period the excavation remains open.

8.5.3        During the operational phase, atmosphere within utility manholes and chambers shall be checked for methane, carbon dioxide and oxygen prior to entry. The Code of Practice on Safety and Health at Work in Confined Space should be followed before entering into the utility manholes and chambers. 

8.6                 Noise Impact

8.6.1           Construction activities would, if unmitigated, generate high noise levels exceeding 75 dB(A) Leq(30-min) at the NSR identified in close proximity to the Tai Po Sewage Treatment Plant. By adopting silenced equipment and good site practices, the mitigated noise levels at the NSR due to this Project would comply with the daytime construction noise standard as set out in the EIAO-TM.

8.6.2           Noise monitoring during construction phase would have to be carried out to ensure that such mitigation measures would be implemented properly. Detailed monitoring requirements are addressed in the stand-alone EM&A Manual.