13 Conclusion

13.1 Conclusion of EIA Study

13.1.1 This EIA Report has provided an assessment of the potential environmental impacts associated with the construction and operation of the Project, based on the engineering design information available during the course of EIA study.

13.1.2 The assessment has been conducted, in accordance with TM-EIAO, covering the following environmental issues:

· Air Quality Impact;

· Noise Impact;

· Water Quality Impact;

· Sewerage and Sewage Treatment Implications;

· Waste Management Implications;

· Land Contamination;

· Landscape and Visual Impacts; and

· Hazard to life.

13.1.3 The findings of this EIA study have determined the likely nature and extent of environmental impacts predicted to arise from the construction and operation of the Project. During the EIA process, environmental control measures have been identified and incorporated into the planning and design of the Project, to achieve compliance with environmental legislation and standards during both the construction and operation phases. The Implementation Schedule listing the recommended mitigation measures is presented in Appendix 11.1.

13.1.4 Overall, the EIA study for the SHD Replanning Works, SHO and the associated modification works at existing AEL/TCL has predicted that the Project, with the implementation of the mitigation measures, would be environmentally acceptable with no adverse residual impacts on the environmentally sensitive receivers and resources. Table 13.1 below summarises the key environmental outcomes and benefits that have accrued from the environmental considerations and analysis during the EIA process and the implementation of environmental control measures of the Project is summarized in Table 13.1 below. The summary of key assessment assumptions and limitation of methodologies and the summary of environmental impacts are presented in Appendices 13.1 and 13.2 respectively.

13.1.5 The various sections of this EIA Report have presented the measures to minimise the potential environmental impacts associated with the Project throughout the construction and operational phases. The key measures to minimise the environmental impacts are summarised in Section 12.6.

13.1.6 Environmental monitoring and audit (EM&A) requirements have been recommended, where necessary, to check on project compliance of environmental legislation and standards. These are presented in a separate, stand-alone EM&A manual.

Table 13.1 Summary of Key Environmental Outcomes and Benefits

Environmental / Social Benefits of the Project	· Optimise the land resources of an existing 30-ha railway depot site for property development which could create a sustainable community in phases; · Enhance local environment in Siu Ho Wan area through the confinement of future depot operation within a concrete slab/ podium deck such that potential environmental impacts associated with the industrial activities could be minimised; · Increase the flexibility for future land use planning of the Siu Ho Wan area by isolating the industrial interface within a concrete slab/podium deck; · Enhance the transportation network in Siu Ho Wan area through the provision of SHO; and · Improve the local environment with the provision of SHO which would in future alleviate the traffic burden on the surrounding road network and the associated vehicular emissions and traffic noise in Siu Ho Wan area
Environmentally Friendly Design and Options	· Avoidance of encroachment into recognized sites of conservation importance; · Avoidance of marine transportation as far as practicable; · Minimisation of environmental impacts to SHD Topside Development; · Adoption of environmental friendly construction method; · Avoidance of emergency discharge from sewage pumping station (SPS); · Adoption of proactive measures to avoid illegal dumping; · Provision of railway noise mitigation measures; and · Implementation of environmental monitoring and auditing system.
Air Quality Impact	Construction Phase: · Major potential air quality impacts during the construction works of the Project would be construction dust arising from excavation, materials handling, spoil removal, pilling, backfilling works, haul road and wind erosion of exposed area. With the implementation of recommended dust suppression measures including watering once per hour on active works areas, exposed areas and unpaved haul roads, and mitigation measures specified in the Air Pollution Control (Construction Dust) Regulation and EM&A programme, the predicted dust impact on the air sensitive receivers would comply with the dust criteria as stipulated in EIAO-TM and air quality objectives (AQO). Operation Phase: · Gaseous and particulate emissions generated from exhaust emissions of equipment used for maintenance operations are expected to be insignificant as the equipment is operated on a routine but infrequent basis. With the operation activities at Reprovisioned SHD same as those at existing SHD, it is anticipated that there would be no additional and insignificant air quality impact arising from the operation of Reprovisioned SHD. · No air quality impact is expected from the operation of SHO with emission free electric-powered rail system and thus the exhaust air from railway operations would be insignificant. In addition, exhausts for general ventilation and smoke extraction facilities will be carefully positioned to avoid causing nuisance to the surrounding environment. Thus, air quality impact during operation phase of SHO is considered insignificant. · No adverse odour impact from the sewage pumping stations (SPS) would be anticipated with the implementation of deodouriser (at least 95% of odour removal efficiency) and maintaining a slight negative pressure of the ventilation system within the facilities and locating the exhaust outlet of the deodouriser away from the nearby ASRs, as far as practicable.
Noise Impact	Construction Phase: · Potential construction noise impact arising from the operation of powered mechanical equipment (PME) would be expected. With the implementation of mitigation measures including use of quiet powered mechanical equipment and use of movable noise barriers/enclosure for some construction activities, the predicted construction noise levels at the representative noise sensitive receivers would comply with the construction noise criteria stipulated in TM-EIAO. Operation Phase (Fixed Noise Sources): · Maximum allowable sound power level emitted from planned fixed plant have been predicted. The fixed plant noise impacts predicted at the existing and planned NSRs would comply with the respective noise criteria. Operation Phase (Railway Noise): · The potential rail noise impacts associated with the operation of existing SHD and TCL/AEL will be alleviated by the provision of the mitigation measures including self-protecting building design, cantilevered noise barrier and noise canopies along the podium edge of SHD Topside Development for protecting the affected NSRs to acceptable noise levels. Alternative approaches in noise mitigation package could be further explored by the Project Proponent of SHD Topside Development in the detailed design stage. Cumulative Operational Noise Impact: · Based on the findings of cumulative operational noise impact assessment, the mitigated noise levels at all representative NSRs would comply with the noise criteria as stipulated in the TM-IND. It is therefore concluded that, with implementation of the recommended noise mitigation measures for fixed plant, mainline operation and train operation within SHD, there would be no adverse cumulative operational noise impacts to the NSRs.
Water Quality Impact	Construction Phase: · Water quality impacts from land-based construction would be controlled by implementing the recommended mitigation measures and good site practices. Regular site inspections would be carried out to minimise water quality impacts. Operation Phase: · Various precautionary measures are proposed to be incorporated in the design of the SPS to avoid consequences of pump and/or power failure to the maximum practicable extent. With the incorporation of the precautionary measures, no emergency sewage discharge during the operation of SHO and Reprovisioned SHD is anticipated and the potential water quality impact in the unlikely event that discharge does occur would be minimised. · Storm water control measures including adequate storm drainage system with suitable pollutant removal devices and best storm water management practices will be adopted for the Project to minimise the potential water quality impact.
Sewerage and Sewage Treatment Implications	· Upon the review on the sewage flow generated from this Project, the SHWSTW should have sufficient capacity to cater for the projected sewage arising from the Project and SHD Topside Development. No adverse impact due to the cumulative sewerage generation from the Project and the SHD Topside Development on the existing sewerage system is anticipated. · With the implementation of mitigation measures including the provision of twin rising mains, dual feed power supply, spare pumps, emergency storage and control system etc, no emergency sewage discharge during the operation of SHO and Reprovisioned SHD is anticipated. · Based upon the assessment, it can be concluded that the proposed Project is sustainable from sewerage collection, treatment and disposal perspective.
Waste Management Implications	· The main waste types to be generated during the construction phase of the Project will include construction and demolition (C&D) materials, chemical waste, general refuse and excavated sediment. Reduction measures have been recommended to minimise the amount of materials generated by the Project by reusing C&D materials and excavated sediment as far as practicable before offsite disposal. Provided that the waste is handled, transported and disposed of using approved methods, adverse environmental impacts would not be expected. · The main waste types to be generated during the operation phase of the Project will include chemical waste and municipal solid waste. Provided that the waste is handled, transported and disposed of using approved methods, adverse environmental impacts would not be expected.
Land Contamination	· Based on the findings from desktop review and site reconnaissance, 9 facilities / areas within the existing SHD have been identified as potentially contaminated. · As the concerned areas are still in operation and undertaking the SI works at this stage is not feasible due to significant impact to the existing SHD operations and the need for maintaining the depot function to support existing operating railway lines, the SI works and any necessary remediation action are recommended to be carried out after decommissioning of the facilities but prior to construction works at the concerned areas. The recommended further works, including the submission of Supplementary CAP(s), CAR(s) / RAP(s) and RR(s), would need to follow EPD’s Guidance Manual, Guidance Note and Practice Guide. · The chemicals of concern (COCs) identified with the potential to be present at the potentially contaminated areas include metals, VOCs, SVOCs, PCRs and PCBs. Remediation methods that have demonstrated to effectively treat the aforementioned soil and groundwater contaminants include biological treatment and physical / chemical treatment; as demonstrated by the successful remediation of soil contaminated with the abovementioned COCs in other Hong Kong projects. By implementing the recommended further works, the actual contaminated site(s) within the assessment area would be located and any contaminated soil and groundwater would be identified and treated. · Given the above, land contamination impacts are therefore considered not insurmountable.
Landscape and Visual	· On review of the likely LR and LCA residual impacts arising from construction and operation of the Project, the majority of LRs would be subject to Insubstantial impact, while only one LR would continue to be subject to Moderate impact by operational Year 10. Besides, All LCAs would be reduced to Insubstantial impact by operational Year 10. Review of the likely visual residual impacts also indicates all VSRs would be subject to Insubstantial to Slight impact by operational Year 10. The residual landscape and visual impact is considered acceptable with mitigation measures implemented during construction and operation phases.
Hazard to Life	· With careful planning and design of the Project, the proposed scheme has completely avoided locating additional population within the CZ of SHWWTW to minimise potential risk. · The criterion of Annex 4 of the TM-EIAO for Individual Risk met with regards to the hazards to life posed by SHWWTW. The societal risk for the cumulative impact from SHWWTW in the construction and operational phases also falls within the ALARP region of stipulated criteria under TM-EIAO. A cost-benefit analysis has been undertaken considering a range of mitigation measures but no mitigation measures are cost effective. Nevertheless, precautionary measures for chlorine released from SHWWTW such as provision of emergency plan for efficient evacuation including good practice (i.e. adequate training and drills for construction workers) during construction phase shall be implemented to further reduce the risk level.

Appendix 13.1	Key Assessment Assumptions and Limitation of Assessment Methodologies
Appendix 13.2	Summary of Environmental Impacts