14 CONCLUSION.. 14-1

14.1 Introduction. 14-1

14.2 Environmental Outcomes. 14-10

14.3 Air Quality Impact 14-14

14.4 Noise Impact 14-14

14.5 Water Quality Impacts. 14-15

14.6 Waste Management Implications. 14-15

14.7 Land Contamination Impact 14-15

14.8 Marine Ecological Impact 14-16

14.9 Landscape and Visual Impact 14-16

14.10 Cultural Heritage Impact 14-16

14.11 Environmental Monitoring and Audit 14-17

14.12 Overall Conclusion. 14-17

14 CONCLUSION

14.1 Introduction

14.1.1 The Project is a designated project in accordance with Item F.6 of Part I of Schedule 2 of the EIAO, which specifies “A submarine sewage outfall”.

14.1.2 This EIA Report has provided an assessment of the potential environmental impacts associated with the construction and operation of the Project, with the consideration of the potential cumulative impact from other projects including the Central Reclamation Phase III (CRIII) and Hong Kong Convention and Exhibition Centre Atrium Link Extension projects. Since the details of the potential future railway projects, i.e. Shatin Central Link (SCL) and North Hong Kong Island Line (NIL) were not available at the time of this EIA study, the cumulative impacts from these two railway projects could not be addressed. Specific mitigation measures requirements for the Project, as well as an environmental monitoring and auditing programme, have been developed during the assessment of the proposed developments. The Implementation Schedule of the recommendations is presented in Section 13. A summary of the environmental impacts associated with the Project are present in Table 14.1. The key assessment assumptions, limitation of assessment methodologies and all obtained relevant prior agreements with the EPD or other authorities on individual environmental media assessment components are given in Appendix 15.1. The key environmental outcomes arising from the EIA study and the principal findings of the study are summarized in Section 14.2.

Table 14.1 Summary of Environmental Impacts Associated with the Project

Environmental Issue	Sensitive Receivers/ Assessment Points	Impact Prediction Results	Relevant Standards/ Criteria	Extents of Exceedances	Impact Avoidance Measures/ Mitigation Measures	Residual Impacts
Air Quality
Construction Phase	4 assessment points	No adverse dust and emission impacts would be expected during dredging activities as dredging is a marine-based activity; and limited emissions from one operated dredgers last for one month (taking into account of concurrent activities). .	EIAO-TM and Air Quality Objective	Nil	The operated dredgers and equipments should be regularly maintained to minimise emissions during construction phase	Nil
Operational Phase	4 assessment points	Effluent from Wan Chai East Preliminary Treatment Works would be discharged to Victoria Harbour via the proposed sewage outfall. As the distance between the discharge location and the nearest ASR is more than 620 m, no adverse odour impact from the effluent is anticipated.	EIAO-TM	Nil	Not Applicable	Nil
Noise
Construction Phase	N2 and N3	Predicted noise levels would be in the range of 69 to 81 dB(A).	Domestic premises: 75dB(A)	Domestic premises: Exceed the noise standard by up to 6dB(A).	Use of quiet equipment and movable noise barriers to mininise construction noise impact	Nil
Operational Phase	Not Applicable	In view of the project nature, no adverse noise impact during the operation phase would be anticipated.	Nil	Not Applicable	Not Applicable	Nil
Water Quality
Potential SS elevations from dredging for construction of the sewage pipeline	All water sensitivity receivers in Victoria Harbour, Western Buffer and Eastern Buffer WCZs	The model results indicate exceedances of WSD water quality (SS) criterion for flushing water intakes (at Quarry Bay, Sai Wan Ho, Sheung Wan, and Wan Chai) and target SS level at Admiralty Centre cooling water intakes. Full compliance with the assessment criterion for sedimentation rate	WSD water quality criterion for SS: < 10 mg/l Target SS level at Admiralty Centre and MTRC cooling water intakes: < 40 mg/l Sedimentation rate at corals: <100g/m^2/day	Maximum SS levels predicted at the WSD flushing water intakes ranged from 15.9 mg/l to 33.1 mg/l. Maximum SS levels predicted at Admiralty Centre and MTRC cooling water intakes ranged from 26mg/l to 58.5 mg/l. No exceedance for the sedimentation rate was predicted	Restriction on the maximum dredging rates at the sewage pipelines zone, water mains zone, TWB, HKCEC Stage 1 & 3 as well as the western seawall of WCR1 which is close to the WSD intake at Wan Chai; Deployment of silt curtains around seawall dredging and seawall trench filling in NPR, TCBR, WCR and HKCEC areas. Deployment of silt screens at selected seawater intakes	Nil
Waste Management Implications
Construction Phase	Not applicable	Main waste: dredged marine sediment with a total volume of approx. 0.03Mm^3.	1. Waste Disposal Ordinance (Cap. 354)	Not applicable	Refer to Table 13.4	Nil
		Other wastes: general refuse from the workforce; chemical waste from plant and equipment maintenance; and C&D material from excavation works and the demolition of existing structures.	2. Waste Disposal (Chemical Waste) (General) Regulation (Cap. 354)
			3. Land (Miscellaneous Provisions) Ordinance (Cap. 28)
			4. Public Health and Municipal Services Ordinance (Cap. 132) - Public Cleansing and Prevention of Nuisances Regulation
			5. Annexes 7 & 15 of EIAO TM
Marine Ecological Impacts
Construction Phase	Ecological resources in the assessment area	- Temporary loss of less than 0.5 ha soft bottom benthic & subtidal habitats	Not applicable	Not applicable	- As no adverse ecological impact on marine habitats and associated wildlife is predicted, no necessary mitigation measure specific for marine ecology is considered as required in this assessment. The mitigation measures recommended in the water quality impact assessment to control water quality would also serve to protect marine ecological resources from indirect impacts and ensure no adverse impact on marine life would be resulted from this designated project.	Not expected
		- Changes in water quality - More than 30% increase of SS at the immediate vicinity outside reclamation area - Insignificant elevation of SS at far-field sensitive receivers - Level of TIN is predicted to be slightly higher than WQO standard at several locations immediately outside reclamation area - Minimum depth-averaged DO at HKCEC is predicted to be slightly lower than 4.0mg/L	(See water quality assessment)	(See water quality assessment)
		Disturbance impact	Not applicable	Not applicable
Operational Phase	Ecological resources in the assessment area	- No direct or indirect impact on marine ecological resources is predicted
Landscape and Visual Impact
Construction Phase	All Landscape Resources / Landscape Character Areas and Visual Sensitive Receivers within the study area	- There will still be some slight negative visual impact on the VSRs in the front row of high rise buildings along the waterfront from Central to North Point.	1. EIAO and TM, particularly Annexes 10 and 18,	Not applicable	- Control of night-time lighting.	Landscape Impacts There will be no landscape impact during construction.
		- The impact on the Victoria Harbour is primary due to the construction of the submarine section of the sewage outfall.	2. EIAO Guidance Note 8/2002,		- Erection of decorative screen hoarding compatible with the surrounding setting.	It is considered that the residual impacts on Victoria Harbour are slight with implementation of mitigation measures.
						Visual Impacts With implementation of mitigation measures during construction, there will be some slight negative visual impact on the VSRs in the front row of high rise buildings along the waterfront from Central to North Point. Residual impacts VSRs further away the Victoria Harbour and from the hinterland will become slight or insubstantial.
Operational Phase	All Landscape Resources / Landscape Character Areas and Visual Sensitive Receivers within the study area	There will be no landscape and visual impact during operation.	1. EIAO and TM, particularly Annexes 10 and 18, 2. EIAO Guidance Note 8/2002, 3. Town Planning Ordinance (Cap 131),	Not applicable	Not applicable	Landscape Impacts There will be no landscape impact during operation. Visual Impacts During operation, the visual impact will be insubstantial.
			4. ETWB TCW No. 2/2004 - Maintenance of Vegetation and Hard Landscape Features.
Cultural Heritage Impact
Construction Phase	Marine archaeological resources in Victoria Harbour	Since there is no archaeological material present within the study area, no adverse cultural heritage impact is expected.	1. Antiquities and Monuments Ordinance (Cap.53) 2. Environmental Impact Assessment Ordinance (EIAO) (Cap. 499, S.16)	Not applicable	No further archaeological investigation or mitigation measures is required	Nil
			3. Technical Memorandum on the Environmental Impact Assessment Process (EIAO-TM)
			4. Guidance Notes on Assessment of Impact on Sites of Cultural Heritage in Environmental Impact Assessment Studies (GN-CH)
			5. Hong Kong Planning Standards and Guidelines (HKPSG) 6. Marine Archaeological Investigation Guidelines.

14.2 Environmental Outcomes

14.2.1 The major environmentally sensitive areas within the study area include residential buildings, commercial buildings, hotels, recreational areas, educational institutions, and WSD flushing water intakes and cooling water intakes at the waterfront of Victoria Harbour. With the implementation of the proposed control and mitigation measures, the air, noise and water quality sensitive receivers within the study area would be protected from adverse environmental impacts arising from the Project during both construction and operational phases. A summary of the key environmental outcomes arising from the EIA study and environmental benefits of the environmental protection measures recommended are presented in Table 14.2 below.

Table 14.2 Summary of Key Environmental Outcomes/ Benefits

Issue	Environmental Outcomes/Benefits
The Project	Requirements: The Wan Chai West Sewage Screening Plant will be decommissioned once flows have been diverted to the Wan Chai East Sewage Screening Plant. The Wan Chai East Sewage Screening Plant will have adequate capacity to handle these flows. However, in the longer term, the existing sewage outfall will need to be upgraded to handle the future design flows. A new sewage outfall will be constructed under the project to replace and upgrade the existing Wan Chai East sewage outfall. The configuration of the new sewage outfall will comprise a landfall section of 2,250mm diameter pipe with approximate length of 180m, and a marine section of twin 1,600mm diameter submarine pipelines of about 550m length.
	Benefits: The existing sewage outfall has to be reprovisioned to enable the construction of the reclamation and Trunk Road. The project provides opportunity to upgrade the sewage outfall to handle the future design flows. In environmental terms, water quality at Victoria Harbour would be similar for both the situations with and without the Project.
	Potential consequences without the Project: Should the existing sewage outfall not be reprovisioned under the Project, the existing sewage outfall will be damaged by the reclamation works and the construction of the Trunk Road. Without a sewage outfall, the Wan Chai East Sewage Screening Plant cannot operate.
Development Alternatives	The alternative to constructing a new sewage outfall to reprovision the existing one is to construct a deck-over structure above the existing sewage outfall. However, this alternative option is considered not feasible as the Trunk Road tunnel will be crossing the existing pipeline at the same level and there will be problems for future maintenance of the pipeline below the deck structure. Construction of a new sewage outfall is considered a reasonable and practicable solution.
Construction Air Quality Impact	Environmental benefits of environmental protection measures recommended: Negligible air quality impact from the DP5 would be expected at the nearest ASRs. The operated dredgers and equipments should be regularly maintained to minimise emissions during construction phase. Compensation areas included: Not required. Population and environmental sensitive receivers protected: Existing air sensitive receivers within 500m of the project boundary.
Operational Air Quality Impact	Environmental benefits of environmental protection measures recommended: Effluent from Wan Chai East Preliminary Treatment Works would be discharged to Victoria Harbour via the proposed sewage outfall. As the distance between the discharge location and the nearest ASR is more than 620 m, no adverse odour impact from the effluent is anticipated. Compensation areas included: Not required Population and environmental sensitive receivers protected: Existing and planned air sensitive receivers within 500m of the project boundary.
Construction Noise Impact	Environmental benefits of environmental protection measures recommended: The predicted mitigated noise levels would range from 62 to 71 dB(A) at the representative NSRs. With the implementation of quiet PME and movable noise barriers under the Project and the noise mitigation measures under other concurrent Schedule 2 DPs, the noise levels at all representative NSRs would comply with the construction noise standard.
	Compensation areas included: Not required.
	Population and environmental sensitive receivers protected: Noise sensitive receivers within 300m of the project boundary.
Operation Noise Impact	Environmental benefits of environmental protection measures recommended: In view of the project nature, no adverse noise impact during the operation phase would be anticipated
	Compensation areas included: Not required Population and environmental sensitive receivers protected: No noise sensitive receiver would be affected.
Water Quality Impact	Environmental benefits of environmental protection measures recommended: The major water quality impact associated with the new sewage outfall would be the potential SS elevations within the water column from the dredging works during the construction phase. Provided the recommended mitigation measures are implemented, including restriction on the maximum dredging rates, the deployment of silt curtains at the other specified current dredging and filling areas activities within the WDII work site, and installation of silt screens at seawater intakes, there will be no unacceptable residual water quality impact due to the proposed dredging works. During the operational phase, the screened sewage currently discharged from the existing Wan Chai East (WCE) and Wan Chai West (WCW) submarine outfalls would be diverted to the new WCE submarine outfall to be constructed under the WDII. It is not expected that there would be any adverse impacts on the overall water quality in the Victoria Harbour due to such change in local distribution of sewage discharges. In addition, the sewage generated from the WCE and WCW catchments would be diverted to the Stonecutters Island Sewage Treatment Works (SCISTW) for CEPT treatment under the Harbour Area Treatment Scheme (HATS) Stage 2A by 2013. No unacceptable impacts would be expected from the new Wan Chai East submarine outfall during the operational phase. Compensation areas included: Not required. Population and environmental sensitive receivers protected: Seawater intakes along the waterfront of Victoria Harbour and corals identified in Junk Bay, Green Island and Cape Collinson.
Waste Management Implications	Environmental benefits of environmental protection measures recommended: With the implementation of the recommended mitigation measures and practices, potential air, odour, noise, water quality for the handling, transportation and disposal of the identified waste arisings, no adverse environmental impacts are expected.
	Compensation areas included: Not required.
	Population and environmental sensitive receivers protected: Water quality, air, and noise sensitive receivers at or near the Project site, the waste transportation routes and the waste disposal site.
Land Contamination Impact	Environmental benefits of environmental protection measures recommended: No potential contaminative land uses were identified within the Study Area. As such, adverse land contamination impacts associated with the construction and operation of the Project is not expected. Compensation areas included: Not required. Population and environmental sensitive receivers protected: · No construction worker would be affected.
Marine Ecological Impact	Environmental benefits of environmental protection measures recommended: The benthic, intertidal and subtidal habitats within the affected area are of very low ecological value. Hence, adverse direct ecological impact is not expected. Water quality and noise control measures (as described above) would minimise indirect impact on marine habitats and associated flora and fauna due to change in water quality and noise environment during the construction phase. Compensation areas included: Not required. Population and environmental sensitive receivers protected: No ecological sensitive receiver would be affected.
Landscape and Visual Impact	Environmental benefits of environmental protection measures recommended: · A submarine sewage outfall will be constructed in Victoria Harbour
	· It is considered that the residual impacts on Victoria Harbour are slight with implementation of mitigation measures and in substantial during operation phase.
	· With implementation of mitigation measures during construction, there will still be some slight negative visual impact on the VSRs in the front row of high rise buildings along the waterfront from Central to North Point. Residual impacts VSRs further away the Victoria Harbour and from the hinterland will become slight or insubstantial. During operation, the visual impact will be insubstantial as the sewage outfall will be underneath the harbour.
	Compensation areas included: Approximately 13.8 ha of new waterfront open space and nine new pedestrian links to the new harbour-front will be provided Population and environmental sensitive receivers protected: Existing and planned Landscape Resources , Landscape Character Area and VSR at and near the project site.
Cultural Heritage Impact	Environmental benefits of environmental protection measures recommended: Since there are no marine archaeological resources within the study area that would be affected by the project, marine archaeological impact due to the construction activities is not expected. No environmental protection measure is required. Compensation areas included: Not required. Population and environmental sensitive receivers protected: No archaeological resources would be affected.

14.3 Air Quality Impact

Construction Phase

14.3.1 Negligible dust impact from dredging and insignificant emission impact from the operation of the plants and dredgers during construction phase would be expected. Air quality monitoring and audit programme is considered unnecessary.

Operational Phase

14.3.2 Effluent from Wan Chai East Sewage Screening Plant would be discharged to Victoria Harbour via the proposed sewage submarine outfall. As the distance between the discharge location and the nearest ASR is more than 620 m, no adverse odour impact from the effluent is anticipated.

14.4 Noise Impact

Construction Phase

14.4.1 This assessment has predicted the construction noise impacts of the Project during normal daytime working hours, taking into account other concurrent projects including other Schedule 2 DPs. The predicted unmitigated noise levels would range from 69 to 81 dB(A) at the representative NSRs. With the use of quiet PME and movable barriers for the Project and implementation of the noise mitigation measures for other Schedule 2 DPs, the predicted cumulative noise levels at the representative NSRs would comply with the construction noise standard.

14.4.2 A construction noise EM&A programme is recommended to check the compliance of the noise criteria during normal daytime working hours.

Operational Phase

14.4.3 In view of the project nature, no adverse noise impact during the operation phase would be anticipated.

14.5 Water Quality Impacts

14.5.1 The major water quality impact associated with the new sewage outfall would be the potential SS elevations within the water column from the dredging works during the construction phase. Provided the recommended mitigation measures are implemented, including restriction on the maximum dredging rates, the deployment of silt curtains at the other specified current dredging and filling areas activities within the WDII work site, and installation of silt screens at seawater intakes, there will be no unacceptable residual water quality impact due to the proposed dredging works.

14.5.2 During the operational phase, the screened sewage currently discharged from the existing Wan Chai East (WCE) and Wan Chai West (WCW) submarine outfalls would be diverted to the new WCE submarine outfall to be constructed under the WDII. It is not expected that there would be any adverse impacts on the overall water quality in the Victoria Harbour due to such change in local distribution of sewage discharges. In addition, the sewage generated from the WCE and WCW catchments would be diverted to the Stonecutters Island Sewage Treatment Works (SCISTW) for CEPT treatment under the Harbour Area Treatment Scheme (HATS) Stage 2A by 2013. No unacceptable impacts would be expected from the new Wan Chai East submarine outfall during the operational phase.

14.6 Waste Management Implications

14.6.1 A review of the sediment quality data from the marine ground investigation indicated that the majority of marine sediments to be dredged for the project are classified as contaminated. The total dredged volume during the construction of the sewage outfall is estimated as approximately 0.03 Mm³, of which 0.018 Mm³ is classified as contaminated (Category M and H) requiring Type 2 confined marine disposal, and 0.012 Mm³ is classified as Category L and would be suitable for Type 1 open sea disposal. With the implementation of the recommended mitigation measures in accordance with the requirements of ETWB TCW No. 34/2002, no adverse residual impact is predicted.

14.6.2 Wastes generated by the construction activities are likely to include C&D material (including demolition material), general refuse from the workforce and chemical waste from the maintenance of construction plant and equipment. C&D material with suitable characteristics would be reused on-site as far as practicable. Surplus material would require disposal to designed public filling facilities. Provided that these identified waste arisings are handled, transported and disposed of using approved methods and that recommended good site practice are strictly followed, adverse environmental impacts would not be expected during the construction phase.

14.7 Land Contamination Impact

14.7.1 No potential contaminative land uses were identified within the Study Area. As such, no adverse land contamination impacts associated with the construction and operation of the Project is expected.

14.8 Marine Ecological Impact

14.8.1 Literature reviews of existing information supplemented with the results of recently undertaken field surveys on marine ecological resources indicated that identified marine habitats within the Assessment Area are of low ecological value. There are no ecological sensitive receivers, such as SSSIs, Marine Parks and / or Reserves and other areas of ecological importance or conservation interest, in and within the immediate vicinity of the Assessment Area.

14.8.2 Direct and indirect ecological impacts arising from this designated project during construction phase were identified and evaluated. The designated project would result in the temporary loss of less than 0.5 hectare of soft bottom benthic and subtidal habitats in the coastal area of the Victoria Harbour. Considering that the benthic and subtidal habitats within the Assessment Area are of very low ecological value, no adverse direct ecological impact is expected.

14.8.3 Indirect disturbance impact on the associated waterbirds and other avifaunal species of conservation interest foraging in the Victoria Harbour and the CBTS was expected to occur during the construction phase of this project. Considering the existing background of intense human activities in these areas, the affected wildlife are considered already well adapted to human disturbance and therefore no adverse indirect impact is expected to occur.

14.8.4 Other impacts arsing from this project would be temporary and minimised with implementation of proper mitigation measures. Overall, no adverse ecological impacts on marine resources are anticipated.

14.9 Landscape and Visual Impact

14.9.1 The proposed development and associated works follow in principle the planning intentions from the Metroplan, Visions and Goals for Victoria Harbour prepared by Town Planning Board and the views of the public received during the engagement exercises of the HER that was carried out under the steer of HEC Sub-committee on WDII Review. In respond to the CFA judgment on the PHO, the extent of reclamation has been reduced to the minimum. With the new waterfront development proposals together with enhanced connectivity to the waterfront from the hinterland and east-west linkages along the northshore, the landscape planning framework of the waterfront from Wan Chai to North Point is strengthened and reinforced by the proposed project.

14.9.2 A submarine sewage outfall will be constructed in Victoria Habour. It is considered that the residual impacts on Victoria Harbour are slight during construction with mitigation measures and insubstantial during operation phase.

14.9.3 With implementation of mitigation measures during construction, there will still be some slight negative visual impact on the VSRs in the front row of high rise buildings along the waterfront from Central to North Point. Residual impacts VSRs further away the Victoria Harbour and from the hinterland will become slight or insubstantial. During operation, the visual impact will be insubstantial as the sewage outfall will be underneath the harbour.

14.10 Cultural Heritage Impact

14.10.1 The results of the MAI in 2001 (Report No. SDA8827) are applicable to the current study since they cover the same seabed area. There have not been any significant changes to the seabed since 2001 which would have affected its archaeological potential. According to the MAI in 2001, it was concluded there were no archaeological resources within the project area of the Wan Chai East Sewage Outfall.

14.11 Environmental Monitoring and Audit

14.11.1 Environmental monitoring and audit (EM&A) are recommended for construction dust monitoring, construction and operation noise, and water quality. Site inspection / audit is also recommended for waste management during construction and also for implementation of landscaping measures during operation. Details of the recommended mitigation measures, monitoring procedures and locations will be presented in a stand-alone EM&A Manual. This will enable the Contractor to have early warning and provide necessary action to reduce impacts at specific areas if the assessment criteria are approached. The effectiveness of on-site control measures could also be evaluated through the monitoring exercise. All the recommended mitigation measures should be incorporated into the EM&A programme for implementation.

14.12 Overall Conclusion

14.12.1 The EIA has been conducted based on currently available information and has been adequately addressed the environmental impacts of this Schedule 2 designated project. No outstanding issues were identified and hence further detailed EIA study was considered not necessary. The findings of this EIA have provided information on the nature and extent of environmental impacts arising from the construction and operation of the Project. The EIA has, where appropriate, identified mitigation measures to ensure compliance with environmental legislation and standards.

14.12.2 Overall, the EIA Report for this DP has predicted that the Project will generally comply with the environmental standards and legislation after the proposed construction and operational stage mitigation measures are implemented. This EIA has also demonstrated the general acceptability of the residual impacts from the Project and the protection of the population and environmentally sensitive resources. Environmental monitoring and audit mechanisms have been recommended before and during construction and operation, where necessary, to verify the accuracy of the EIA predictions and the effectiveness of recommended mitigation measures.