11                      IMpactS SUMMARY

11.1                 Introduction

11.1.1           The Project is a Designated Project in accordance with Item C.12 of Part I, Schedule 2 of the EIAO, which specifies an “a dredging operation exceeding 500,000 m3”.  This EIA Report has provided an assessment of the potential environmental impacts associated with the Project, with the consideration of the potential cumulative impact from other projects. Specific mitigation measures requirements for the Project, as well as an environmental monitoring and audit (EM&A) programme, have been developed during the assessment of the proposed Project.  A summary of the environmental impacts associated with the Project are presented in Table 11.1.  The key assessment assumptions, limitation of assessment methodologies and all relevant prior agreements with the EPD on individual environmental media assessment components are given in Appendix 11.1.  The Implementation Schedule of the recommendations is presented in Section 12.  The key environmental outcomes arising from the EIA study and the principal findings of the study are summarized in Section 13.

11.2                 Air Quality Impact

11.2.1           Dredging activities are marine based activities and negligible dust impacts on nearby ASRs would be expected.  Referring to the marine site investigation results, the AVS levels measured in all the sediment samples collected from the dredging area of the proposed cruise terminal were below the detection limit of 1 mg/kg.  In general, high AVS concentrations in sediment indicate that odorous hydrogen sulphide gas is likely to be generated from the sediment.  These AVS levels are far below the AVS levels of the odour remediated sediments collected from Shing Mun River and Sam Ka Tsuen Typhoon Shelter.  Therefore, it is expected that the potential odour emissions from the sediments within the dredging area of the proposed cruise terminal would be minimal and adverse odour impact from the dredging activities in the Stage 1 and 2 areas would not be anticipated.  Adverse odour impacts during the capital dredging are therefore not expected.  Maintenance dredging would be carried out once every 5 to 10 years and adverse odour impacts at ASRs are also not expected.

11.3                 Noise Impact

11.3.1           This assessment has predicted the construction noise impacts of the Project during normal daytime working hours, taking into account other concurrent projects within a 300m study area.  Based on the latest available information, there are no existing NSRs identified within 300m from Project boundary and only two representative planned NSRs are identified for assessment during the Stage 2 dredging period as a conservative approach.  Under the unmitigated scenario, the noise levels at all the representative planned residential NSRs would comply with the construction noise standard, and therefore no adverse noise impact is expected.  As the planned NSRs are located closest to Stage 2 work site comparing with Stage 1 work site, assessment for Stage 2 dredging is considered in the Study as a worst case scenario. Good site practices are recommended to further ameliorate the impacts.  A construction noise EM&A programme is recommended to check the compliance of the noise criteria during normal daytime working hours if any planned NSRs within the 300m study area are occupied during the proposed dredging works.

11.3.2           Assessment on noise impact from maintenance dredging was also conducted.  Results indicated that the predicted noise at the nearest NSRs would comply with the construction noise criterion of 75 dB(A).

11.4                 Water Quality Impact

11.4.1           The water quality impact during the proposed dredging works has been quantitatively assessed using the Delft3D Model.  Suspended solids are identified as the most critical water quality parameter during the dredging operations.  The worst-case scenarios for the dredging works have been assessed and it is predicted that potential water quality impacts could occur at the flushing water intakes along the waterfront of the Victoria Harbour.  However, the water quality impacts upon the intakes could be effectively minimized with the implementation of the proposed mitigation measures.  There would be no unacceptable residual water quality impact due to the proposed capital and maintenance dredging works.  An EM&A programme is required to verify whether or not impact predictions are representative, and to ensure that the dredging operations do not result in unacceptable impacts. 

11.5                 Waste Management Implications

11.5.1           The total volume of dredged sediment generated from the dredging of the seabed to provide the manoeuvring basin for the cruise terminal is estimated to be approximately 1.38 Mm3 during construction phase.  Based on the results of the chemical and biological screening, approximately 430,000 m3 was classified as contaminated dredged sediment (Category M and H) requiring Type 1 – Open Sea Disposal (Dedicated Sites) or Type 2 - Confined Marine Disposal, and approximately 950,000 m3 was classified as Category L sediment suitable for Type 1 - Open Sea Disposal in accordance with ETWB TCW No. 34/2002.

11.5.2           The total volume of dredged sediment generated from maintenance dredging during operational phase is estimated to be approximately 350,000 m3 every 5 to 10 years.  Prior to any maintenance dredging, sediment sampling and testing will be carried out in accordance with the ETWB TCW No. 34/2002 to determine the contamination level of the dredged sediment.  The most appropriate open sea or confined marine disposal site will be allocated for proper disposal of the dredged sediment on the basis of the chemical and biological test results in accordance with the ETWB TCW No. 34/2002. 

11.5.3           The total volume of C&D material generated from the removal of the existing seawall by dredging for the berth construction is estimated to be approximately 322,300 m3 during construction phase.  No C&D material would be generated from maintenance dredging during operational stage of the proposed cruise terminal.  Other wastes generated from the capital and maintenance dredging are likely to include chemical waste from the maintenance of construction plant and equipment and general refuse from the construction workforce. 

11.5.4           Mitigation measures are recommended in this EIA to minimise potential environmental impacts associated with handling and disposal of different wastes arising from the Project.  Provided that the recommended mitigation measures are properly followed, adverse environmental impacts would not be expected from the capital and maintenance dredging.

11.6                 Impact on Cultural Heritage

11.6.1           The 2007 MAI did not locate any archaeological resources but it established that it is possible that archaeological material could be deeply buried within the sub-seabed sediments, which may be affected by the proposed dredging.

11.6.2           Due to the depth of proposed dredging and the fact that the archaeological potential of the area cannot be completely ruled out, the need of precautionary measures during dredging is required.  Guidelines for a Monitoring Brief have been prepared in consultation with the AMO.

11.6.3           The heritage significance of the remaining seawall structure is assessed to be low.  Yet, the dredging activities of the proposed cruise terminal should ensure that disturbance to the existing seawall masonry outside the Project boundary should be avoided as far as practicable.

11.7                 Marine Ecological Impact

11.7.1           Literature reviews of existing information with supplement findings from recent field surveys indicated that identified marine habitats within the Project area are of generally very low ecological value.  There are no ecological sensitive receivers, such as SSSIs, Fish Culture Zones and Marine Parks and / or Reserves and other areas of ecological importance or conservation interest, in and within the immediate vicinity of the Project area.

11.7.2           Marine habitats within the Kai Tak area include soft bottom seabed, artificial seawalls, subtidal habitats and feeding ground of waterbirds.  All the identified habitats are considered as generally very low of ecological value due to their highly artificial and disturbed nature. Species diversity and abundance in these habitats were low and no rare or restricted species was recorded.  The species of conservation interest recorded within the Project area only include a single species of common hard coral (Oulastrea crispata) (but all colonies found are small in size, sparsely distributed and in very low coverage) and few species of waterbirds such as Little Egret and Great Egret.  All these species of conservation interest recorded within the Project area are common and widespread in other Hong Kong waters.

11.7.3           Direct and indirect ecological impacts arising from the Project were identified and evaluated. The Project will result in the temporary loss of approximately 57 hectares of soft bottom benthic and subtidal habitats and about 1 km long of artificial intertidal habitat.  Considering that the benthic and intertidal habitats within the proposed dredging area are of very low ecological value and direct impact on some isolated coral colonies would largely be mitigated by translocation, no adverse impact is expected. 

11.7.4           Other indirect impacts arsing from the Project would be temporary and minimised with implementation of proper mitigation measures.  Overall, no significant and unacceptable ecological impact on marine resource is anticipated in this assessment.

11.8                 Fisheries Impact

11.8.1           Literature reviews of existing information indicated that identified fishing area in Kowloon Bay, eastern Victoria Harbour and KTTS are of moderate to high fisheries values while that in TKWTS and KTAC are of relatively low value.  There are no fish culture zones and important spawning or nursery grounds identified in and within the immediate vicinity of the Project area.  The nearest mariculture areas are FCZs at Tung Lung Chau and Ma Wan which are 8 km and over 10 km away, respectively, of the Project area.

11.8.2           Direct and indirect impacts on fisheries resources arising from the Project were identified and evaluated.  The Project will result in the temporary loss of approximately 57 hectares of fishing area.  In view of the small size of affected area, temporary and insignificant loss of fisheries production and low impact on fishing activities, fisheries impacts due to direct loss of fishing area within the dredging area is considered as minor and acceptable. 

11.8.3           Indirect impacts of change of water quality arsing from the Project would be temporary and insignificant based on the predictions from water quality modelling.  Mitigation measures suggested in the water quality impact assessment to control water quality would also serve to protect fisheries resources from indirect impacts.  No significant adverse impact on fisheries resources would be expected from the Project and therefore no necessary fisheries-specific mitigation measures would be required.

11.9                 Overall Summary

11.9.1           This EIA has been conducted based on the best and latest information available during the course of the EIA study.  The findings of this EIA have provided information on the nature and extent of environmental impacts arising from the Project.  The EIA has, where appropriate, identified mitigation measures to ensure compliance with environmental legislation and standards.  Overall, this EIA has 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 the proposed dredging works, where necessary, to verify the accuracy of the EIA predictions and the effectiveness of recommended mitigation measures.  A summary of the environmental impacts associated with the Project is presented in Table 11.1.

Table 11.1                       Summary of Environmental Impacts Associated with the Project

Sensitive Receivers / Assessment Points

Impact Prediction Results

Relevant Standards / Criteria

Extents of Exceedances

Impact Avoidance Measures / Mitigation Measures

Residual Impacts (After Implementation of Mitigation Measures)

Air Quality Impact

 

 

 

 

Planned developments on the former airport runway including:

·       Residential Development

·       Planned Hotel

·       Landscape Deck at Cruise Terminal

·       Planned Runway Park

Dredging activities are marine based activities and negligible dust impacts on nearby ASRs would be expected.  Referring to the marine site investigation results, the AVS levels measured in all the sediment samples collected from the dredging area of the proposed cruise terminal were below the detection limit of 1 mg/kg.  In general, high AVS concentrations in sediment indicate that odorous hydrogen sulphide gas is likely to be generated from the sediment.  These AVS levels are far below the AVS levels of the odour remediated sediments collected from Shing Mun River and Sam Ka Tsuen Typhoon Shelter.  Therefore, it is expected that the potential odour emissions from the sediments within the dredging area of the proposed cruise terminal would be minimal and adverse odour impact from the dredging activities in the Stage 1 and 2 areas would not be anticipated.  Adverse odour impacts during the capital dredging are therefore not expected.  Maintenance dredging would be carried out once every 5 to 10 years and adverse odour impacts at ASRs are also not expected.

The EIAO-TM stipulates that the hourly TSP level should not exceed 500 mgm-3 (measured at 25°C and one atmosphere) for construction dust impact assessment.  Standard mitigation measures for construction sites are specified in the Air Pollution Control (Construction Dust) Regulation.

In accordance with the EIAO-TM, odour impact predicted at an air sensitive receiver should meet 5 odour units based on an averaging time of 5 seconds.

 

Not applicable

Construction Dust

Negligible dust impacts would be expected from dredging activities.  In order to further ensure compliance with the AQOs at the ASRs, requirements of the Air Pollution Control (Construction Dust) Regulation, where relevant, shall be adhered to during the construction period.

Odour Impact from Capital Dredging and Maintenance Dredging

No adverse odour impact is expected from the Project. However as a precautionary measure to minimize the potential odour emissions during dredging operation, if any, the dredged sediment placed on barge should be properly covered during its transportation to the mud dumping pits as far as practicable to minimise the exposed area and hence the potential odour emissions during the  transportation of the dredged sediment.

 

None

Noise Impact

 

 

 

 

 

 

Planned residential developments on the former airport runway.

 

This assessment has predicted the construction noise impacts of the Project during normal daytime working hours, taking into account other concurrent projects within a 300m study area.  Based on the latest available information, there are no existing NSRs identified within 300m from Project boundary and only two representative planned NSRs are identified for assessment during the Stage 2 dredging period as a conservative approach.  Under the unmitigated scenario, the noise levels at all the representative planned residential NSRs would comply with the construction noise standard, and therefore no adverse noise impact is expected.  Good site practices are recommended to further ameliorate the impacts.  A construction noise EM&A programme is recommended to check the compliance of the noise criteria during normal daytime working hours if any planned NSRs within the 300m study area are occupied during the proposed dredging works.

Assessment on noise impact from maintenance dredging was also conducted.  Results indicated that the predicted noise at the nearest NSRs would comply with the construction noise criterion.

 

 

 

 

 

 

 

 

 

The NCO provides the statutory framework for noise control of construction work other than percussive piling using powered mechanical equipment (PME) between the hours of 1900 and 0700 hours or at any time on Sundays and general holiday (that is, restricted hours).  Noise control on construction activities taking place at other times is subject to the Criteria for Evaluating Noise Impact stated in Table 1B of Annex 5 in the EIAO-TM.  The noise limit is Leq (30 minutes) 75 dB(A) at the façades of dwellings and 70 dB(A) at the façade of schools (65 dB(A) during examinations).

 

Not applicable

Good site practices to ameliorate the construction noise impact:

·       Only well-maintained plant should be operated on-site and plant should be serviced regularly during the construction program.

·       Mobile plant, if any, should be sited as far away from nearby NSRs as possible.

·       Machines and plant (such as trucks) that may be in intermittent use should be shut down between works periods or should be throttled down to a minimum.

·       Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from nearby NSRs.

·       Material stockpiles and other structures should be effectively utilised, wherever practicable, in screening noise from on-site construction activities.

 

 

None

Water Quality Impact

 

 

 

 

Seawater intakes along the waterfront of Victoria Harbour and far field coral sites identified in Junk Bay, Green Island and Cape Collinson

 (refer to Figure 5.2).

 

The model results indicate exceedances of WSD water quality (SS) criterion at 6 flushing water intakes along the water front of Victoria Harbour.

 

1. WSD flushing water quality intake criterion for SS: < 10 mg/l

2. Target water quality objectives at coral sites for SS elevations: < 30 % of  the background ambient levels

3. Sedimentation rate at corals: <100g/m2/day

Full compliance would be achieved with implementation of all the recommended mitigation measures

Use of closed grab dredger during maintenance and capital dredging

deployment of silt curtains at appropriate dredging areas, and installation of silt screens at selected seawater intakes during capital dredging

Avoid maintenance dredging in wet season (April to September).

None

Waste Management Implications

 

 

 

 

Water quality, air, and noise sensitive receivers at or near the Project site, the waste transportation routes and the waste disposal site.

 

Main waste: dredged marine sediment with a total volume of approximately 1.38 Mm3 from capital dredging and 0.35 Mm3 once every 5 to 10 years from maintenance dredging

 

Of the sediment to be generated from capital dredging, approximately 430,000 m3 was classified as contaminated dredged sediment (Category M and H)   and approximately 950,000 m3 was classified as Category L sediment

 

Sediment to be generated from maintenance dredging will be tested in accordance with the ETWB TCW No. 34/2002

 

Other wastes:

Chemical waste from plant and equipment maintenance during capital and maintenance dredging; and

 

C&D material (of about 322,300m3) from dredging of the existing seawall at the former airport runway during capital dredging at construction stage. Inert C&D material to be disposed off-site to the designated public fill reception facility

1.     Waste Disposal Ordinance (Cap. 354)

2.     Waste Disposal (Chemical Waste) (General) Regulation (Cap. 354C)

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

6.     Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap. 354N)

(refer to Section 6.2)

Not applicable

Contaminated dredged sediment (Category M and H) would require either Type 1 =- Open Sea Disposal (Dedicated Sites) or Type 2 - Confined Marine Disposal at contaminated mud pit allocated by MFC.

 

Category L sediment is suitable for Type 1 - Open Sea Disposal at gazetted marine disposal ground allocated by MFC.

 

Planning and design measures in reducing waste generation have been discussed in Section 6.7. Besides, other mitigation measures and good site practices on waste management should be incorporated into the contract document to control potential environmental impact from handling of the identified wastes arising from the Project (refer to Section6.7).

 

 

None

Impact on Cultural Heritage

 

 

Archaeological resources within the Project site boundary

The MAI did not locate any marine archaeological remains within the Project site boundary and concluded no further MAI is necessary.

 

Direct impact to the seawall masonry is expected. However, the section of affected seawall within the project boundary has been established to have low cultural heritage value.

 

 

1.    Antiquities and Monuments Ordinance (Cap. 53)

2.    Environmental Impact Assessment Ordinance (EIAO) (Cap. 499, S.16)

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.

(refer to Section 7.2)

Not applicable

It is recommended that the dredging contractor should monitor the dredge spoils. A procedure for briefing the dredging contractors about the possible presence of marine archaeological resources during dredging and a procedure for handling them have been developed in consultation with the AMO, to ensure compliance with the AMO standards and protection of any archaeological resources at the proposed dredging site (refer to Appendix 7.1)

 

The heritage significance of the remaining seawall structure is assessed to be low.  Yet, the dredging activities of the proposed cruise terminal should ensure that disturbance to the existing seawall masonry outside the Project boundary should be avoided as far as practicable.

 

None

Marine Ecological Impact

 

 

-           

 

Ecological resources at and near the Project site

Direct impacts to the marine ecological resources would include temporary loss of approximately 57 hectares of soft bottom and subtidal habitat and about 1km of artificial intertidal habitat. All the marine habitats and associated marine life that would be directly lost are all of very low ecological values and taking into account of all the mitigation measures proposed including coral translocation and provision of newly constructed seawalls, such impact is considered as minor.

 

Indirect impacts on the marine ecology would be associated with changes of water quality due to dredging activities. Considering that the benthic, intertidal and subtidal communities identified in the Kai Tak area are of generally very low ecological value and in view of the temporary nature of such impact, only minor indirect impact on marine resources is anticipated.

 

During the dredging works, increased marine traffic and noise generated from construction plant could cause disturbance impacts to the associated wildlife including the waterbirds of conservation interest. It is expected that displacement of waterbirds to the nearby waters for roosting and feeding area may occur temporarily but adverse impact is not anticipated.

Environmental Impact Assessment Ordinance (EIAO) (Cap. 499).

EIAO Technical Memorandum on EIA Process (EIAO-TM) Annex 8 and Annex 16

EIAO Guidance Note No. 3/2002

EIAO Guidance Note No. 6/2002

EIAO Guidance Note No. 11/2004

Wild Animals Protection Ordinance (Cap. 170)

Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586)

Town Planning Ordinance (Cap.131)

The Marine Parks Ordinance (Cap.476) and Subsidiary Legislation

The Marine Fish Culture Ordinance (Cap.353)

The Protection of the Harbour Ordinance (Cap.531)

The Water Pollution Control Ordinance (Cap.358)

International Union for Conservation of Nature and Natural Resources (IUCN) 2006 Red Data Books

The PRC National Protection Lists of Important Wild Animals and Plants

(refer to Section  8.2)

Not applicable

Coral translocation of directly affected colonies, as far as practicable, to avoid and minimize direct loss of this fauna of conservation interest.

 

Water quality control measures such as installation of silt curtains around dredger(s) and use of closed grab dredger to minimise indirect impact on marine life due to change of water quality.

 

Appropriate good site practices on noise control are recommended to be adopted during the dredging works to minimise noise disturbance to nearby waterbird population.

 

Re-construction of new seawalls to recover loss of artificial intertidal habitats

Temporary loss of 57 hectares of soft bottom benthic habitat of very low ecological value.

 

Water quality modelling predicted that indirect impacts on the marine ecology associated with changes of water quality due to dredging activities within the Project area would be acceptable after implementation of proper mitigation measures.

 

 

Fisheries Impact

 

 

 

 

Fisheries resources at and near the Project site.

The Project will result in the temporary loss of about 57 hectares of fishing area.  In view of the small size of affected area, temporary and insignificant loss of fisheries production and low impact on fishing activities, fisheries impacts due to direct loss of fishing area within the dredging area is considered as minor and acceptable. 

 

Indirect impacts on fisheries resources would be associated with changes of water quality due to dredging activities. In view of the temporary and localised nature of such impact, only minor impact on capture fisheries resources is anticipated. No impact on culture fisheries resources is anticipated as the nearest FCZs Tung Lung Chau and Ma Wan are over 8km and 10km away from the project area respectively.

EIAO-TM Annex 9 and Annex 17 in order to provide complete and objective identification, prediction and evaluation of potential fisheries impacts arising from the Project.

Fisheries Protection Ordinance (Cap. 171) – aims to promote the conservation fish and other forms of aquatic life within the Hong Kong waters by regulating fishing practises to prevent detrimental activities to the fisheries industry.  The Ordinance came into effect on 30 June 1997.

Marine Fish Culture Ordinance (Cap. 353) – regulates and protects marine fish culture by designating areas of fish culture zone, granting license, prohibiting unauthorized vessels and any deposition of chemicals or other substance which are likely to cause injury to fish in a fish culture zone.  The list of designated fish culture zones was last revised in January 2000.

The Water Pollution Control Ordinance (Cap.358) – aims to control water pollution in the waters of Hong Kong.  Water control zones are designated with individual water quality objectives to promote the conservation and best use of those waters in the public interest.  The most updated water quality objectives for the Victoria Harbour Water Control Zone were revised in June 1997.

 

Not Applicable

No necessary fisheries-specific mitigation measures would be required.

Temporary loss of 57 hectares of fishing area at Kowloon Bay.

 

Water quality modelling predicted that indirect impacts on fisheries resources associated with changes of water quality due to dredging activities within the Project area would be acceptable after implementation of proper mitigation measures.