3. SUMMARY OF THE KEY FINDINGS IN THE EIA

3.1 Air Quality

Air sensitive receivers

The major air sensitive receivers of concern are the scattered village houses in the vicinity of the landing point of SWC at Hong Kong side at Ngau Hom Shek (see Figure ES3.0A). These air sensitive receivers would be subject to the cumulative impacts from both the SWC and the DBL projects. The landing point of SWC at the Mainland side will be on a future reclamation. The reclamation will be largely used as the future Boundary Crossing Facility for SWC with no air sensitive uses identified in the proximity.

Construction phase

3.1.1 The major potential air quality impacts during the construction phase of the project would result from dust arising from site clearance and preparation, excavation and filling, open site erosion, concrete batching, precasting of road segments, and handling and transportation of construction and demolition material. Practicable and effective dust suppression measures should be implemented to minimise the dust nuisance arising from the construction activities. In particular, the relevant dust control requirements set out in Parts I, III and IV of Schedule 1 of the Air Pollution Control (Construction Dust) Regulation should be adopted by the site agent while carrying out construction works. The specific measures recommended in the EIA include dust suppression by twice daily watering with complete coverage of all active construction areas and limiting the construction vehicle travel speed on unpaved site areas to not more than 10 km per hour. With the implementation of effective dust control measures, adverse dust impacts from the construction works of the project would not be expected.

3.1.2 The modelling results showed that the worst-case unmitigated construction dust impacts at the existing village houses at Ngau Hom Shek could reach 1012 µgm-3 of 1-hour average TSP level and 375 µgm-3 of 24-hour average TSP level. With the implementation of the proposed dust suppression measures, the dust impacts at the existing village houses at Ngau Hom Shek could be on average reduced by about 60% and 53%, respectively, for the 1-hour average TSP level and the 24-hour average TSP level. The highest residual 1-hour average and 24-hour average TSP level at the village houses at Ngau Hom Shek are predicted to be 435 µgm-3 and 214 µgm-3 respectively and exceedance of the respective AQO and guideline level for TSP criteria is not expected.

Operational phase

3.1.3 Major air quality impacts during the operational phase of the project would arise from the tailpipe emissions of vehicles travelling on the proposed SWC. There might also be cumulative air quality impacts at some sensitive receivers due to traffic emissions from the DBL, as well as other planned and existing roads in the area and the stack emissions from major existing and planned sources in the area.

3.1.4 Computer dispersion modelling was undertaken to assess the potential operational phase cumulative air quality impacts due to traffic emissions from the proposed SWC, the future road network in the area and stack emissions from major emission sources. The assessment was based on a conservative assumption that all vehicles travelling on the road network within the assessment area would use fuel with a higher sulphur content and thus with higher emission factors. Another conservative assumption is the use of year 2011 emission factors for design traffic flow at year 2021, given the emission factors would be further improved beyond 2011 due to technology advancement. The modelling results showed no exceedance of the respective Air Quality Objectives (AQO) for nitrogen dioxide, respirable suspended particulates, carbon monoxide, and sulphur dioxide at all the identified existing and future air sensitive receivers within the assessment area of the proposed SWC. Mitigation measures for operational phase air quality impacts would therefore not be required.

3.1.5 The predicted highest 1-hour average and 24-hour average nitrogen dioxide level at the worst-affected air sensitive receivers, namely the existing village houses at Ngau Hom Shek, are 82% and 95%, respectively, of the corresponding AQO. The predicted highest 24-hour average respirable suspended particulates level at the air sensitive receivers is 54% of the corresponding AQO; whereas the highest predicted 1-hour average carbon monoxide level and the 1-hour average and 24-hour average sulphur dioxide levels at the air sensitive receivers are all below 28% of the corresponding AQO.

3.2 Noise

3.2.1 Parts of the SWC would be constructed near existing rural land lots at Ngau Hom Shek. Existing noise sensitive receivers there would be located proximity to the SWC alignment and affected by the construction noise and operational noise to a varying extent. Figure ES3.0A shows the locations of the noise sensitive receivers.

Construction phase

3.2.2 Construction noise assessments were conducted based on the conservative preliminary construction schedule in this preliminary design stage. Due to the close proximity of some of the existing noise sensitive receivers (NSRs), noise levels exceeding EIAO Technical Memorandum criteria were predicted ranging from Leq 76 to 85 dB(A) for the unmitigated scenario. To reduce the likely impacts, different forms of mitigation measures were examined, including the use of quiet plant and working methods, the use of movable and temporary noise barriers, provision of noise screening structures and purpose-built noise barriers. All NSRs could be adequately protected by the proposed mitigation schemes. Residual noise impacts during the construction period would not be expected after applying the proposed mitigation schemes. The predicted worst noise levels at selected NSRs are from Leq 68 to 75 dB(A)

3.2.3 The Project Proponent also planned for construction work during restricted hours (like evening, night-time and public holidays) in the view of the required completion target. This would be under stringent control and the future contractor has to apply for a construction noise permit under the Noise Control Ordinance subject to the approval by the Authority.

Operational phase

3.2.4 Traffic noise impacts would be from SWC during its operation. Noise from road traffic was assessed based on the traffic forecast for year 2021, i.e. the worst within 15 years after the completion of SWC and its linking with DBL. Existing NSRs were included in the assessment. With traffic noise mitigation in mind in the planning process, low-noise surfacing was adopted as a standard provision under the current policy for high speed roads.. All predicted noise levels at NSRs were found to be within acceptable standards. All of the dwellings would be protected from adverse impacts with predicted noise levels from L10(1hr) 65 to 70 dB(A) during peak hour traffic. No residual impacts were identified for the operational phase of the SWC project.

3.3 Hydrodynamics, Water Quality and Sediment Quality

Construction Phase

3.3.2 The key concern on water quality impacts during the construction phase of the Project was sediment plume dispersion generated from bridge pier construction. Mitigation measures were proposed to install cofferdam surrounding the construction area of each bridge pier. Pier construction would be carried out inside the cofferdam, thereby preventing the escape of sediment plumes. Closed grabs would be used to remove sediments inside the cofferdams. Silt curtains would also be deployed as a secondary defense to contain the dispersion of sediment plumes if any. Sediment plume modelling results showed that the increases in SS were higher in the region from Ngau Hom Shek to Pak Nai SSSI due to the close proximity to the dredging sites. The increased SS levels in this region for dredging within the Hong Kong waters only ranged from 1.55 to 4.03 mg/L respectively. There was, however, no exceedance of WQO for suspended solids (less than 30% increase over background value) at all the identified water sensitive receivers. Figure ES3.0B shows the locations of the water sensitive receivers. A sensitivity test was included to assess the cumulative water quality impacts from the reclamation and dredging activities on the Mainland side. Modelling results also showed that there was no exceedance of WQO for suspended solids at all the water sensitive receivers.

3.3.3 Sediment dredging would be required for bridge pier construction. Category L, M and H materials were found in the Site Investigation. The sediment volumes for open sea disposal and confined marine disposal were estimated to be approximately 34,500m3 and 22,500m3 respectively.

3.3.4 An enhancement measure would be implemented to restore the functions of Mai Po Gei Wais. Sediment dredging in the inlet channel and the proposed access route would be required. Category M and H materials were found in the Site Investigation and the estimated volume of sediment to be disposed of at confined marine disposal sites was about 8,800 m3.

Operational Phase

3.3.5 Hydrodynamic and water quality modelling was conducted to assess changes in flushing capacity that would also lead to changes in water quality of Deep Bay due to the reclamation at Dongjiaotou and the SWC bridge piers. The Delft3D suite of models used for simulations incorporated the reclamation at Dongjiaotau and bridge piers. The 75m span, which is longer than the span length of 50m considered in the Crosslink Study, was adopted in the preliminary bridge design to minimise the effect on flushing capacity. Besides the span, other factors that could reduce friction (and therefore minimise reduction in flushing capacity) were also incorporated into the design of the bridge. These included the adoption of submerged (into the mud layer) pile caps and streamline shaped piers. Reduction in flushing capacity caused by the bridge piers alone was predicted to be 0.76% (seasonal average). The reclamation at Dongjiaotou and the bridge piers together would reduce flushing capacity by approximately 3.3% (seasonal average). The average changes in TIN, SS, UIA, E. coli, DO, BOD5 and salinity within the inner region of Deep Bay were about 2.49, 2.33, 1.82, 1.25, -0.41, 1.38% and -0.73% respectively. The predicted changes in sedimentation rates in Deep Bay were small (0.3-0.5mm/yr at Mai Po and Ramsar Site). The small changes in water quality and sedimentation rates should be deemed insignificant.

3.3.6 The recent aerial photographs taken over the study area showed that the intertidal mudflat in the study area was inundated with oyster beds. These oyster beds obstruct water movement and therefore affect the flushing capacity. This Project would result in the permanent removal of approximately 16 ha of oyster beds along the alignment over the inter-tidal mudflat. The removal of oyster beds could improve the flushing capacity by approximately 0.38%. The changes in water quality and sedimentation rates in Deep Bay would be lower than the predicted results.

3.3.7 Frequent cleaning of vehicle-generated pollutants from the SWC bridge using vacuum air sweeper was recommended to minimise the potential impacts on mudflat and the Deep Bay waters from bridge runoff. Monitoring of bridge runoff during the operational phase would be implemented to determine the effectiveness of the mitigation measure.

3.3.8 The accident rate for DGV on SWC bridge were estimated to be very low. An Emergency Response Framework was developed to consolidate the existing emergency response plans being implemented by relevant government departments. A detailed Emergency Response Plan would be developed based on the Emergency Response Framework. A joint effort from the relevant government departments would be implementation to deal with the spill incident on the bridge. The potential risk of DGV accident is expected to be insignificantly low.

3.3.9 A summary of the recommended mitigation measures to minimise water quality impacts during the construction and operational phases is presented in the following table:

3.4 Waste Management

Construction phase

3.4.1 Effective waste management planning during the construction phase would be the key issue. The potential sources of wastes identified for the SWC are marine dredged sediments, excavated materials, construction and demolition material (C&DM), chemical waste, and general refuse.

3.4.2 Vibrocoring and grab sampling carried out during the Site Investigation to determine sediment quality in the study area indicated the presence of Category L, M and H materials. This Report identified that confined marine disposal should be adopted for the Category H dredged sediment and for Category M sediment which fails the biological tests. The other sediment samples classified as Category L material can go to open sea disposal, as should Category M material which pass the biological tests (dedicated sites). The sediment volumes for open sea disposal and confined marine disposal were estimated to be approximately 34,500 m3 and 22,500 m3, respectively. Licensed vessels should be employed for display of marine dredged sediment in accordance with relevant Port and Shipping Regulations.

3.4.3 The dredged material from the inlet channel and access route at Mai Po for the proposed enhancement measure were Category M and Category H material and which can be disposed of at confined marine disposal site, i.e. East Sha Chau mud pits. An estimate of the dredged material is approximately 8,800 m3.

3.4.4 Impacts from excavated materials are expected to be minimal, as all permanent works for the SWC would be located offshore and the land issues are covered under the DBL project.

3.4.5 Considerations such as selection of alignment option were taken into account in the planning and design stages to reduce the generation of construction and demolition material. The total volume of construction and demolition material to be generated is estimated to be about 700 m3, of which about 20% could be reused or recycled.

3.4.6 The quantity of chemical waste generated from SWC is expected to be small and would be stored, handled, transported and disposed in accordance with the Code of Practice on the Packaging, Labelling and Storage of Chemical Waste issued by EPD. Disposal of chemical waste, if any, would be at a licensed chemical waste treatment and disposal facility. The potential impacts arising from chemical waste generation would be minimal. Licensed waste collectors should be employed for disposal of chemical waste.

3.4.7 General refuse, estimated at a total volume of about 151 tonnes over the 2.5-year construction period, would be stored and transported by licensed waste collector for off site disposal at licensed landfills. With proper handling of general refuse, there would be no unacceptable environmental impacts.

3.4.8 Waste management methods and practices and other environmental control measures for the construction phase were recommended to ensure that potential impacts would be avoided or mitigated to acceptable levels. Potential environmental impacts associated with wastes from the Project would be insignificant, with the proper implementation of all the suggested mitigation measures. The contractor would be required to follow the requirements of the Waste Management Plan included in this EIA.

Operational phase

3.4.9 The operational phase is not expected to generate any wastes.

3.5 Ecology

3.5.1 The field survey programme of the present project was planned to be an extension of the field surveys for Crosslinks 2 EIA study. A 12-month ecological field survey was conducted for Crosslinks 2 between 1998-1999. Fieldwork for the present project began in August 2001 and continued through June 2002 to provide another 11 months of survey data covering seasonal variation and the breeding season and autumn and spring migrations of birds.

3.5.2 Among the four topographic zones in outer Deep Bay area (upland, lowland, coastal/intertidal, and marine), the present field studies identified habitats and species in lowland and coastal zones as key issues for ecology within the assessment area.

3.5.3 The ecological baseline study has covered all items highlighted in the Study Brief of SWC EIA, i.e. intertidal mudflat; mangrove; seagrass bed; inter-tidal and sub-tidal benthic faunal communities; egretries; Horseshoe crabs; avifauna, in particular, Black-faced Spoonbill (Platalea minor); and Chinese White Dolphin (Sousa chinensis).

3.5.4 During the field surveys for the present project, two plant species, including Thespesia populnea and the seagrass Halophila beccarii, one marine invertebrate (horseshoe crab Tachypleus tridentatus), one reptile, 25 species of birds, two species of mammals, including Chinese White Dolphin, were recorded within the assessment area and are of conservation concern.

3.5.5 Among those species of conservation concern recorded, however, only the seagrass Halophila beccarii, horseshoe crab Tachypleus tridentatus, and 10 waterbird species including Black-faced Spoonbill are considered that their presence in the assessment area is relevant to the SWC project.

Design considerations

3.5.6 In terms of avoidance, based upon information from literature review and field surveys, it was found in the assessment that the current location of the Shenzhen Western Corridor would cause the least impact to Deep Bay. The current location is 6km from Mai Po Marsh Nature Reserve, 7 km from the mouth of Deep Bay, and 3.5km from Ha Pak Nai. The potential impacts on recognised sites of conservation importance would be higher if the corridor location was further northward (potential impacts on Mai Po), or further southward (potential impacts on Chinese White Dolphin). The current location of SWC is thus considered the most ecologically acceptable if a non land-based western corridor is needed.

3.5.7 The most important form of mitigation, avoidance, has already been pursued through consideration of three alternative sites for the bridge landing. The Ngau Hom Shek was determined to be the least damaging ecologically and the most preferred all round

3.5.8 Tunnel option was found to be less ecologically acceptable due to the need of large scale dredging during construction and the higher reduction o flushing rate during operation.

3.5.9 Several design features of the bridge could effectively minimise ecological impacts, including increasing pier spacing, adopting submerged pile caps, locating cable -stayed structure outside intertidal zone, bridge deck height, and no power line suspended on the bridge.

Construction Phase

3.5.10 During construction, the cumulative temporary direct habitat loss will be 2.7 ha in subtidal zone, and 0.75 ha in intertidal zone, due to construction and use of the temporary bridge, plus 0.25 ha removal of mangrove trees. Only less than 0.001 ha of seagrass might be potentially influenced. Temporary direct BFS feeding ground loss would be 0.1394ha. In operation phase, the resulted permanent habitat loss will be only less than 0.2 ha in subtidal zone and 0.024 ha in intertidal zone. Permanent BFS feeding ground direct loss would be 0.039ha.

3.5.11 The indirect impacts on habitats due to disturbance were investigated through additional field surveys in other bridge structures in HK and Macau, and analyses of data in other projects. The finding indicates that most birds are disturbance-tolerant. Even Black-faced spoonbill (BFS), which is previously considered much sensitive to disturbance, was observed feeding close to disturbance sources. Precautionary approach is however adopted. In the worst case scenario, in which unforeseeable incidence occurs at the SWC construction sites during winter, the affected BFS feeding ground is estimated to be 0.24 ha in area, which has included the 0.139ha of idrect temporary loss. Previous studies indicated that mudflat is only one of the feeding ground types of BFS (the other two are drained fishponds and drained gei wai), and the outer deep Bay (including the mudflat near the SWC alignment) is not the core feeding area of BFS. This 0.24 ha represents a small fraction (1.6%) of the intertidal feeding habitat for BFS along the south shore of outer Deep Bay (some 15 km in length x 10 m in width = 15 ha) which is less important to the BFS than the inner Deep Bay. The temporary loss is predicted to be an undetectable impact. For the operation phase, though there is no evidence to prove that BFS would avoid the mudflat in the vicinity of a bridge, based upon a precautionary approach, an additional 30m on both side of the SWC deck width was included to address this potential impact. The total permanent loss of BFS potential feeding ground, including both direct and indirect, would then be 0.039ha + 0.06ha = 0.099ha. Since a 8.34 ha of mudflat would be restored in operation phase, a 0.139 ha tideline (= (39m + 50m + 50m) x 10m) will be provided. After reduction of the 0.099 ha potential loss, there still would be 0.04ha tideline feeding ground for BFS restored.

3.5.12 There would be no cumulative impacts in terms of disturbance. The only cumulative impact identified was an additional ~150ha seabed loss. The loss was insignificant to Deep Bay. Even including the seabed loss from the SWC project, the cumulative seabed loss would be only about 1.3% of Deep Bay. The cumulative impacts from the present project would be acceptable.

3.5.13 During construction, dredging, intertidal habitat loss, damage due to construction and use of the temporary bridge may result in minor impacts on mudflats, mangroves, seagrass, and pelagic species.
3.5.14 All other construction impacts would be insignificant in severity.

3.5.15 Implementation of the recommended mitigation measures would result in no unacceptable residual impacts.

Operational Phase

3.5.16 All long-term impacts from operation of the bridge were predicted to be insignificant or minor and could be mitigated with no unacceptable residual impact.

Additional enhancement measures

3.5.17 Additional enhancement measures are, however, proposed to contribute to the long-termed goodness of the Deep Bay ecosystem, including a programme to locate and removal of exotic mangrove species and weeds (such as Sonneratia spp. & Spartina sp.) and a plan to restore the function of Gei Wais in Mai Po as bird feeding ground.

3.5.18 By recovering the level of the bottoms of water channels connecting Gei Wais and Deep Bay, the function of 24.3 ha Gei Wai in Mai Po, which is the core feeding ground of BFS, will be restored. This area would be over 20 times the temporary peripheral feeding ground loss for all birds in the SWC construction phase. This plan will be conducted before the commencement of SWC construction works and the function restoration achieved could last for over a decade.

3.6 Fisheries

3.6.1 An outline of the fisheries baseline for the area, an assessment of likely fisheries impacts from project construction and operation, and options for impact mitigation were provided.

3.6.2 A review of existing information, supplemented by the results of recently undertaken field surveys, on commercial fisheries resources located within and around the assessment area confirmed that fisheries resources in Deep Bay were neither abundant nor of high value in comparison to resources in other fishing areas of Hong Kong.

3.6.3 Potential impacts to fisheries resources and operations may arise from permanent or temporary loss of capture fisheries area or oyster culture area, and/or changes in water quality.

3.6.4 The 40 pairs of bridge piers in HKSAR waters will permanently occupy about 0.22 hectares of seabed, 0.196 ha of which would be in subtidal zone, and 0.024 ha of which would be in the mudflat zone.

3.6.5 The 0.22ha of seabed loss would constitute a loss of about 0.01 % of the total fishing ground in Fishing Area 48 (Lau Fau Shan, 2,107.43 ha in area). This impact is ranked as minor.

3.6.6 Since the area of mudflat cleared for the construction works (139m in width) would not be available for oyster farming again, the 16 ha inside works area would constitute a permanent loss of potential oyster farming sites. An estimate showed that the area of mudflat along the south shore of Deep Bay from Tsim Bei Tsui to Ha Pak Nai is 747 ha. This figure represents the total area of HKSAR mudflat available for oyster bed farming. The permanent loss of 16 ha would constitute a 2.1 percent reduction in the potential area for oyster beds within Deep Bay. Due to the small area permanently affected by the bridge, and the progressive decline of the oyster culture industry in HKSAR, the potential project impacts upon oyster culture are considered minor.

3.6.7 The potential percentage losses in capture fisheries would be small compared to the overall resources in HKSAR. Therefore any loss of fisheries resources, e.g. 16 ha of mudflats and 0.196 ha of sea areas, were considered to be of minor significance to the fishing industry.

3.6.8 Sediment deposition could be caused by dredging for bridge piers or by site runoff. If site management practices were strictly enforced, runoff and contamination would be minimal and was not anticipated to impact fisheries resources.

3.6.9 Changes in water quality would be minimal, therefore adverse impacts to fisheries resources were not predicted.

3.6.10 After implementing mitigation measures for water quality, including cofferdams, closed grab dredgers, silt curtains and standard site practices, no significant adverse impacts were predicted on any fishing grounds, species or practices of importance to the local or HKSAR fishery. About 23 oyster rafts will be relocated to suitable locations before the commencement of the construction works. Oyster raft operators are required to be consulted on the relocation operation before commencement of any works.

3.6.11 While no direct mitigation measures would be required for fisheries, standard site practices to control impacts to water quality to within acceptable levels should mitigate impacts to fisheries resources.

3.6.12 Cumulative impacts with other concurrent projects would not result in greater adverse impacts to fisheries resources than impacts arising from the concurrent projects alone.

3.7 Hazard to Life

3.7.1 Comparison of different alignment options concluded that the s-curve bridge alignment was the preferred option. Under the requirement specified in the EIA Study Brief, hazard assessment would only be required in the case of overnight storage of explosives in close vicinity of populated areas or PHI site. The construction of the s-curve bridge would not involve the use of explosives. Therefore, quantitative assessment on the potential risk due to storage, handling and on-site treatment was not required, and hazard to life due to overnight storage of explosives would not be an issue in this Study.

3.8 Cultural Heritage

3.8.1 An archaeological survey identified the Ngau Hom Shek Beach Site as a site of cultural heritage. No further archaeological work could be conducted, as the site is now almost entirely covered by a piggery. The western part of the Ngau Hom Shek Beach Site was found to be located within the impact zone of SWC. Preliminary design indicates that viaduct structures and stormwater drain pipe are within this area. Therefore, a rescue excavation with the programme agreed by AMO must be carried out on this site before any earthworks or building works could commence.

3.8.2 The coastal area at Ngau Hom Shek to the immediate west to the proposed SWC landing point is not accessible for archaeological survey at this stage but the possibility of identifying significant archaeological remains can-not be completely excluded, although the archaeological potential of this area is low. It is recommended therefore to conduct a further archaeological survey and, if necessary, to carry out a rescue excavation in the project area with earthworks and building works by the project proponent after land resumption and before the commencement of construction works of the site.

3.8.3 For the area subject to landscape works in the Ngau Hom Shek Beach Site (including the west of the site if necessary) should be filled up to a level that the adverse impact of the proposed tree roots to the existing ground can be avoided. The remaining part of the site will not directly affected by the construction but it should be protected from potential indirect impact with a layer of soil (30 cm minimum) covered on the top.

3.8.4 The Ngau Hom Shek Hill Site of the prehistoric period is located slightly outside and above the impact zone of the proposed SWC landing point, the construction therefore will not cause direct adverse impact to this site. It should be emphasized, however, the site area should be protected from indirect impact potentially caused by the construction, and facilities and activities related to the construction should be kept away from the site during the entire process of construction.

3.8.5 A Marine Archaeological Investigation (MAI) was carried out for the seabed covering the section of the route in HK territorial waters. There were five Unidentified Targets within the southern section of the study area, which are found to be outside the EIA Study limit. Diver inspection for the area not covered in the previous MAI due to shallow water and oyster beds is required along the strip of area directly beneath the SWC only. The visual inspection of the archaeological investigation area found no visible features or objects of archaeological interest. This may be result of the high sedimentation rates in the area and the extensive disturbance to the seabed from fishing and oyster cultivation or the absence of archaeological features. Due to the proximity of the archaeological investigation area to the coastal archaeological site, Ngau Hom Shek, the potential for such resources cannot be ruled out. However, based on the visual inspection and review of the site conditions, the archaeological potential is classified, as very low and further investigation is not recommended.

3.9 Landscape and Visual

3.9.1 Landscape and visual impacts associated with the Shenzhen Western Corridor (SWC) were assessed in accordance with the Environmental Impact Assessment Ordinance which became law in Hong Kong on 1st April 1998. Both construction and operation impacts were assessed.

Summary of Landscape Impacts (see Figure CE3.1)

3.9.2 The unmitigated landscape impacts during the construction phase will generally be moderate to substantial for all Landscape Resources and Landscape Character Zones with the exception of Grassland / Eroded Slopes which will experience slight impacts and Ponds will experience negligible landscape impacts. With mitigation, the impact will generally be reduced to moderate, with the exception of Stream Channel Resources, the Village Coastal Lowland and Sea Edge Landscape Character Zones which will retain moderate to substantial impacts.

3.9.3 The unmitigated landscape impacts during the operation phase will generally be moderate to substantial for all Landscape Resources and Landscape Character Zones. With mitigation, the residual impact will generally be reduced to slight to moderate, with the exception of Stream Channels Resources, the Village Coastal Lowland and Sea Edge Landscape Character Zones which will retain moderate to substantial impacts.

3.9.4 Areas affected for each Landscape Resource are provided in the table below:

Tree Impacts

3.9.5 Vegetation at the edges to the Agricultural and Green Belt areas will be affected. The vegetation within the alignment is generally of poor quality. From the most update to Tree Survey Report, 96 trees will be affected by the works of which 17 will be retained. Approximately 45 will be transplanted in the area as part of the tree compensation plan. The unmitigated magnitude of the impacts on this vegetation is considered moderate.

3.9.6 Landscape impacts along Fung Kong Tsuen Road will be limited to the felling of some existing trees for road widening works. 60 trees will be affected including 9 different species. Generally the trees affected are between 4-6m in height. There are 4-5 significant trees adjacent to the road but on the current alignment these trees should not be affected. These significant trees included Celtis sinensis, Delonix regia, Aleurites moluccana, Eucalyptus citriodora and Litchi chinensis.

Summary of Visual Impacts

3.9.7 The unmitigated visual impacts during the construction phase will generally be slight to moderate with the exception of the residents of Ngau Hom Shek which will experience substantial impacts. With mitigation, the impact will generally be reduced to slight to moderate, with the exception of the residents and walkers of Ngau Hom Shek and Walkers along the coastal edge who will retain moderate impacts.

3.9.8 The unmitigated visual impacts during the operation phase will generally be slight to moderate with the exception of the residents of Ngau Hom Shek which will experience substantial impacts. With mitigation, the residual impact will generally be reduced to slight to moderate, with the exception of the residents and walkers of Ngau Hom Shek which will retain moderate impacts. The visual impact upon travellers on the SWC (VSR12) are identified as slight positive.

Summary of Mitigation Measures

3.9.9 A number of landscape and visual mitigation measures for reducing the residual impacts caused during the construction and operation phase have been recommended.

3.9.10 Construction Phase measures include Conservation (excavation and stockpiling on site) of topsoil for re-use in landscape works. This includes the proper storage of topsoil to minimise erosion of stockpiles; Control of night-time lighting; Replanting of disturbed vegetation should be undertaken and this should use predominantly native plant species; Screen hoarding, using decorative graphic and chromatic devises should be erected around the works wherever possible to screen the works from motorists and other receivers within the road corridor and adjacent areas; Maintaining and protecting existing vegetation adjacent to Deep Bay Road for a minimum width of 10 metres on either side; Planting within and at the perimeter of temporary work sites should be undertaken at the earliest possible stage before and during construction, and opportunities should be sought for undertaking any advance planting; and existing trees to be transplanted as per the Master Landscape Plan.

3.9.11 Operation Phase mitigation measures include Woodland tree and shrub planting should be implemented adjacent to the Deep Bay Road where it is at grade. This will include cut and filled slopes; Implementation of bio-engineering techniques to the cut slopes; Climbing plants should be used to soften the appearance of viaduct columns at ground level; Woodland tree and shrub planting should be undertaken at cut slopes so as to compensate for vegetation lost during construction. Any affected slope areas should be hydroseeded and planted with woodland species, avoid shotcreting; Native shrub planting should be undertaken to screen the proposed works and blend it into the landscape; Planting should be incorporated where possible to screen the road and bridge in low level views from adjacent areas, and to tone down the extent of hard paving and surfaces and reduce the amount of glare; Sensitive architectural design of engineering and other built structures, including form and finishes, this will include but not limited to: barriers, paved surfaces, retaining walls, walls, columns, buildings, and other structures, light standards, etc. The design of built structures shall be to the satisfaction of the ACABAS; Lighting of road and bridge. Should be designed to minimise glare to all receivers. Poles and fittings should be designed to conform with the bridge design; and Transplanted Tree Stock in accordance with the Master Landscape Plan.

3.9.12 An example of proposed mitigation measures in Greenbelt is shown on Figures CE3.2 and CE3.3.
Conclusion

3.9.13 Many bridge structures are seen as a positive attribute to visual environments. The route over Deep Bay will offer outstanding views to motorists of Deep Bay and the coastlines of North West New Territories and Shenzhen. The bridge design can generally be viewed as a positive aesthetic for these travellers. In addition, the perception of the bridge as a 'landmark' structure with positive visual attributes should also be considered

3.9.14 All impacts must be considered in relation to the proposed Deep Bay Link Road. The study area overlaps with the study area for the DBL by 350 metres and many of the potential impacts (particularly landscape impacts) are reflected in both studies.

3.9.15 Overall, it was considered that, in terms of Annexe 10 of the EIAO TM, the landscape and visual impacts would be acceptable with mitigation measures.

3.10 Environmental Monitoring and Audit

3.10.1 A comprehensive Environmental Monitoring and Audit (EM&A) programme was recommended to ensure that the construction and operational phase impacts from the SWC project would be within acceptable levels. The EM&A requirements covered the following issues:

· air quality - baseline and construction phase dust monitoring;
· noise - baseline and construction and operational phase monitoring;
· water quality - upstream control and downstream impact monitoring during both construction and operational phases, site runoff monitoring during construction phase, and operational phase auditing;
· waste management - construction phase auditing;
· ecology - construction and operational phase monitoring and audit; and
· landscape and visual - design, construction, and operational phase auditing.

3.10.2 With the implementation of EM&A requirements, the SWC project would not cause unacceptable environmental conditions.

3.10.3 Environmental monitoring will also be implemented by the Shenzhen side to ensure that the construction of SWC within the Mainland boundary would be in compliance with the Mainland environmental standards. It has been established between Highways Department and the Shenzhen authorities that a formal channel will be set up between the two offices for the SWC project in case of the occurrence of cross border environmental pollution problems.