14.1.1 This report presents the environmental assessment of the environmental impacts relating to the proposed improvement to Tung Chung Road alignment option. Full details of the justification and background to the project are provided in Section 1. The preferred alignment has been selected after a comprehensive option assessment process in which the environmental implications of each alternative was a key consideration and the alignment options selected deemed to be the most preferable on environmental grounds (see Appendix B). The avoidance and minimisation of environmental impacts as far as practicable has been a major objective during the assessment and selection of the preferred route and through the progressive design of the selected alignment. Thus, the proposed alignment represents the optimum route after balancing all relevant factors, within the engineering and topographical constraints.
14.1.2 The main characteristics of the alignment which have been designed to minimise the environmental effects of the road are as follows:
¨ alignment widened on-line as far as possible to minimise habitat loss;
¨ haul road specified along the same alignment as the main route as far as practicable to reduce the extent of temporary habitat loss;
¨ alignment designed on viaduct where appropriate and with the use of retaining walls in order to significantly reduce the extent of cut slopes required, having ecological benefits;
¨ alignment designed to cross all key ecologically sensitive streams on structure during both the construction and operational stages to avoid direct impacts on the aquatic environment;
¨ construction runoff in the northern section to be collected into a special pipeline and transported to the nullah in Tung Chung and treated via sedimentation tanks prior to discharge. This will avoid discharge into the northern streams which are tributaries of the highly sensitive Tung Chung stream. In the south, all run-off collected and treated using sedimentation tanks and oil interceptors prior to discharge to protect the streams and the water gathering grounds. Discharge into Cheung Sha Stream avoided;
¨ special pipe also designed to carry road runoff to either end of the alignment to avoid discharge into any stream course during the operational phase;
¨ permanent drainage system designed to avoid direct impacts on Fong Yuen Marsh and the channelised section of Tung Chung stream which is proposed to be upgraded; and
¨ layout and size of the bus bay facilities designed to minimise land take.
14.2.1 The assessment of construction related impacts have included: air quality, noise, water quality, construction waste, ecology, landscape and visual and hazard to life. The assessment of impacts during the operation of the project have included: air quality, noise, water quality, ecology, landscape and visual, hazard to life and heritage impacts.
14.2.2 The Remaining Development in Tung Chung and Tai Ho Comprehensive Feasibility Study has proposed sensitive development north of the Tung Chung Valley which could be affected by the operation of the improved Tung Chung Road. Thus, for the purposes of this report, the effects on this development together with the cumulative effects of the two projects have been assessed. In addition, the potential for operational air and noise impacts at proposed future sensitive receivers on the sale sites in Cheung Sha has also been assessed. The key findings of the EIA are given in Sections 14.3 and 14.4 below.
18.104.22.168 Potential dust nuisance will be the key concern from the construction works. The major sources of dust on site have been assumed to be from construction work, vehicular movement over unpaved haul roads and erosion of exposed surfaces. Both 1-hour and 24-hour TSP concentrations at representative ASRs along the route have been determined and based upon an unmitigated scenario it is predicted that only some representative sensitive receivers would be subject to dust impacts in excess of either the 1 hour or 24 hour standards. However, with the implementation of the dust control measures, the impacts can be reduced to acceptable levels. Mitigation measures recommended include:
¨ not burning debris or other materials on the works areas;
¨ watering all unpaved roads;
¨ watering exposed site areas;
¨ watering during rock breaking;
¨ minimising dropping heights for excavated materials;
¨ dampening and covering of materials during transportation;
¨ minimised areas of exposed soil and restored as soon as is practicable; and
¨ covering and watering all stockpiles.
22.214.171.124 In addition to these measures, under the auspices of the Air Pollution Control (Construction Dust) Regulation, the Contractor will be required to ensure that dust control measures stipulated in the Regulation should be implemented to control dust emissions.
126.96.36.199 Although construction impacts are predicted to be reduced to acceptable levels through the implementation of the recommended mitigation measures, construction phase environmental monitoring and audit has been recommended to ensure that the mitigation measures are effective. Detailed specifications for the EM&A are provided in the EM&A Manual.
188.8.131.52 Impacts on air quality during the operation of the improved Tung Chung Road will be due to vehicular emissions from traffic using the road. Based morning peak hour traffic flows and vehicle mixes for the Year 2021, the worst case year for the operational air quality assessment 15 years after the proposed opening of the road, and EURO 3 vehicular emission factors, operational concentrations of nitrogen dioxide and respirable suspended particulates have been predicted at all representative ASRs. The results show that all parameters comply with the relevant AQOs. This conclusion also applies to the future sensitive receivers in Cheung Sha. Thus, no mitigation is required.
184.108.40.206 The construction activities for the Project can be divided into five broad areas, namely roadworks and bridgeworks for the main alignment and activities required for the construction of noise barriers, stabilisation of unstable boulders and slope remediation works. No blasting works will be allowed along the road.
220.127.116.11 During slope stabilisation works, the use of a helicopter for equipment drop off and pick up will be required in certain areas. It has been determined that due to the distance of the sensitive receivers from the works areas, the noise levels is not expected to exceed the 75 dB(A) standard or the 85 dB(A) maximum criteria. The results of the construction works associated with the bridge works and the slope stabilisation and remediation works showed that noise exceedances were not predicted at the sensitive receivers.
18.104.22.168 However, the results for the road and noise barrier construction indicate that, in certain locations including Tung Chung Valley, maximum noise levels at some of the NSRs will exceed the day time noise criteria of 75dB(A). Mitigation measures are, therefore, required to reduce the noise levels to meet the standards. The mitigation recommendations are as follows:
¨ silencers should be installed at the exhaust pipes for the engines of the bulldozers, lorries, concrete lorry mixers, chipper, poker, cranes, excavators and dump trucks;
¨ the poker should have an acoustic cover on the engine; and
¨ temporary noise barriers should be used to screen construction activities at SRs 4, 13 and 15 during road construction and SR 2 and 4 during permanent noise barrier construction.
22.214.171.124 In addition, only one breaker should be used within 200m of SR4 in Tung Chung and SRs 13 and 15 in Cheung Sha and the operation time of the breaker, dump truck, bulldozer and grader needs to be restricted by 50% at SR13 during excavation of earth / rock and removal, forming of earthworks and retaining wall foundation works. Use of the recommended mitigation is sufficient to reduce noise levels to within acceptable limits for all sensitive receivers, with in the region of 44 dwellings being protected by these measures.
126.96.36.199 Operational noise predictions have been carried out based upon peak hour traffic flows and vehicle mixes for the worst case year of 2021. The noise modelling has concluded that the majority of sensitive receivers would not be subject to operational noise levels in excess of the 70 dB(A) limit as a result of their distance from the alignment. However, the village properties in Tung Chung Valley are adjacent to the road and will be subject to elevated levels in excess of the standard. Thus, direct mitigation measures are required for the NSRs affected by the project. A full range of mitigation options have been considered for the protection of the NSRs to ensure that the optimum scheme is recommended.
188.8.131.52 Reflective barriers, ranging in heights from 1.5m to 4.5m and totalling over 127m in Tung Chung Valley have been proposed to protect the sensitive receivers from operational noise impacts resulting from the project. Approximately 10 dwellings will be protected by these barriers in the Tung Chung area. Many of the properties in Ha Ling Pei and Wong Ka Wai are subject to elevated noise levels from the existing Tung Chung Road which is outside this project limit. The practicality of retrofitting of barriers was investigated but due to constraints associated with the need to maintain access points to the villages, only one section of 70m of barrier was identified as being practical for future consideration. These properties are also not eligible for indirect technical remedies.
184.108.40.206 Impacts at some of the closer proposed future sensitive receivers at the sale sites are also predicted and it is recommended that mitigation measures be provided to protect the future receivers. The EIA has shown that the inclusion of a 2m landscaped earth bund, together with a 4m non building area, would be sufficient to protect the properties.
220.127.116.11 In order to ensure the recommended mitigation measures are effective, noise monitoring during both the construction and operational phases has been recommended. Detailed specifications for the EM&A are provided in the EM&A Manual.
18.104.22.168 Potential impacts during the construction phase will be relevant primarily to the inland water courses, although downstream impacts in the marine waters at either end of the alignment are possible.
22.214.171.124 The northern section of the new road runs up along the east side of Tung Chung Valley above Tung Chung Stream. The distance between the road and the stream varies along the route. At Lung Tseng Tau, the stream is about 210 m away from the road. However, as the road climbs the valley towards the crest at Pak Kung Au, the road passes as close as about 30 m to the stream in several locations, whilst crossing over a number of tributaries to the stream. In the southern section of the road, the alignment also passes over two tributaries of the Cheung Sha Stream.
126.96.36.199 Thus, site runoff has the biggest potential to cause impacts to inland waters during the construction stage and careful design of a runoff catchment and treatment system will be required. Pollution of the sensitive streams in the study area represented one of the key environmental problems to be addressed in the EIA. The implementation of good construction site practices such as restricting stock piling in areas near watercourses, covering stock piled materials and minimisation of exposed areas to rain by carrying out reinstatement as soon as possible, will be required to reduce the suspended solid concentrations. However, given the importance of the streams in the study area and the water gathering grounds, in addition to the above, the widening of the road has been restricted to the east side of the existing road as far as possible, such that during construction, the existing road can be used as a buffer zone to help prevent any pollutants from running into Tung Chung Stream. The only locations where roadworks will be required on the west side of the existing road are in the vicinity of Burial Ground No. 18L and Tai Tung Shan Service Reservoir. Also the selected alignment is the furthest from the Cheung Sha stream.
188.8.131.52 In addition, a drainage system has been devised to avoid / minimise water quality impacts as far as possible. For the northern section of the new road, it is proposed that the operational drainage system be constructed ahead of the main roadworks such that it may be used to discharge the construction site runoff, thus avoid discharging construction site runoff into the streams all together. The discharge outfall for the northern section’s drainage system will be located in the “Wong Lung Hang Channel” nullah near Ha Ling Pei and all discharge will be treated via a sedimentation tank in order to minimise impact on Tung Chung Bay and the San Tau SSSI. seagrasses. South of the crest, it is proposed to use a series of peripheral surface channels to encase sections of the works site to intercept and divert the surface runoff from the hinterland and the construction site. All run-off will be treated by a series of sedimentation tanks prior to discharge into adjacent streams. Oil interceptors will also be used above the catchwater to further protect the water gathering grounds.
184.108.40.206 The key aspects of the proposed temporary drainage system which will be adopted to ensure the protection of the water quality in the inland streams and Tung Chung Bay during construction are as follows:
¨ system designed to have no discharge of site run-off into Tung Chung Stream;
¨ northern temporary drainage system will avoid discharge into any steams;
¨ system in the southern area divided into small sub-catchments to enhance control and minimise impacts;
¨ all run-off treated via a sedimentation tank prior to discharge either into streams in southern area or marine environment;
¨ oil interceptors used above catchwater to protect water gathering grounds;
¨ all parts of system will be regularly cleaned and maintained;
¨ hinterland runoff separated to protect from contamination; and
¨ system must be operational before the commencement of the permanent works.
220.127.116.11 Thus, based upon the inclusion of these measures, the risk of adverse impacts to water quality during the construction phase has been reduced to a negligible level.
18.104.22.168 Impacts may also result from the discharge of wastewater from temporary site storage areas and maintenance and refuelling of plant and mitigation measures are recommended. The effects of litter and waste construction material can be limited by the use of good site management practices and in respect of lavatory facilities for the workforce, chemical toilets or on-site chemical treatment facilities would be required where connection to a sewer is not practicable.
22.214.171.124 Stream diversions, culverting, widening or bank strengthening works have been avoided as far as possible on key ecological streams with the road passing over the water courses on structure, with the exception of 4 streams. However, impacts on these 4 streams will be very short term and not considered to be significant. The temporary haulage road has also been designed to pass over the stream courses on bridges, thus, protecting against direct impacts to the streams. Streams which do not support any key ecological species and have low basal flow may be subject to new culverts, widening of existing culverts and widening of existing bridge structures. This will cause direct impacts to the streams but in light of their low ecological importance and low flow, impacts are not considered to be significant.
126.96.36.199 In addition, to the drainage system described above, mitigation measures recommended to reduce any impacts to acceptable levels include:
¨ minimising areas of exposed soil and undertake reinstatement within 3 weeks of areas being completed;
¨ covering of spoil heaps and avoid placement adjacent to any streams;
¨ no major stockpiles in the Country Park;
¨ no storage of fuel or oil in the country Park or water gathering grounds;
¨ no chemical wastes shall be stored in the water gathering grounds;
¨ no canteen facilities shall be located within the water gathering grounds;
¨ the Contractor shall comply with WSD’s General Conditions for Working within Water Gathering Grounds;
¨ the Contractor will be required to prepare a response plan to define procedures for the control, containment and clean-up of any spillage that could occur on the construction site;
¨ no maintenance activities which may generate chemical wastes shall be undertaken in the water gathering grounds;
¨ collecting run off from the roofs of site buildings and conveying to closed drains;
¨ using on-site chemical treatment and storage facilities for wastewater from the site offices and toilet facilities; and
¨ washing vehicle wheels prior to entering and leaving the construction site.
188.8.131.52 EM&A in the form of water quality monitoring of all affected stream courses, together with site inspections has been recommended during the construction period to ensure the effectiveness of the mitigation measures. Detailed specifications for the EM&A are provided in the EM&A Manual.
184.108.40.206 In respect of operational water quality impacts, contaminants in the road surface runoff are expected to be limited and, thus, impacts on the water quality of the streams are expected to be negligible. Notwithstanding, a specially designed carrier pipe along the length of the road will collect and transport all road drainage to either end of the alignment prior to discharge into the nullah at Tung Chung and Pui O Wan. Thus, operational discharge into all streams along the route, and thus the water gathering grounds, has been avoided.
220.127.116.11 Once discharged though the outfall, a dilution factor of at least 10 would be expected relatively quickly and within a few tens of metres from the discharge point. Thus, increases in concentrations of water quality parameters in the receiving waters would be centred within a short distance of the discharge points, much as is the case for the natural streams at present.
18.104.22.168 In Tung Chung, the peak road runoff only amounts to about 1% of the total peak natural runoff. This value is further reduced when the dilution in the marine environment is taken into account, with the runoff from the road being equivalent to about 1% to 2.5% of the tidal volume depending upon the particular tide, based upon a 1:50 year storm. Similar, levels of contribution and dilution would be expected for the southern section of the road and the discharge into Pui O Wan. Thus, any road runoff into the bays at either end of the alignment would not be expected to result in a significant increase in the concentration of the water quality parameters of interest and will not result in a significant increase in the existing pollutant load to Tung Chung Bay or Pui O Wan.
22.214.171.124 In the event of an accident with a tanker, there is the possibility for the spillage of a large volume of oil or chemicals. In this case, the proposed road parapet over much of the roads length would prevent a vehicle from leaving the road and the integrated permanent road drainage system would help to protect the inland streams by collecting the spillage. Thus, in the event that a major spill occurs on Tung Chung Road, a defined response plan has been recommended in order to, not only be able to reopen the road as soon as possible to minimise distruption to Lantau traffic, but also to minimise effects on the local ecological resources and water gathering grounds. Should some oil be discharged via the pipeline into the marine environment, the receiving waters are large bodies of water which would facilitate rapid dilution and dispersion. However, in order to protect the Tung Chung Bay, an oil interceptor is proposed for the discharge at the northern end of the alignment.
126.96.36.199 In view of the predicted negligible effects of any runoff and the adopted drainage system which avoids discharge into any streams or water bodies along the alignment, impacts from road runoff are predicted to be negligible and no further mitigation measures would be required.
188.8.131.52 The key issue for waste management will be control of excavated materials. Waste quantities have been estimated from an assessment of the cut and fill activities determined. It is predicted that there will be an overall surplus of material, with approximately 118,520m3 required to be exported. Assuming an average truck capacity of 7.5m3, approximately 15,800 vehicle trips would be required for the removal of the material over the duration of the job, which would equate to around 4 trips per hour. This is not predicted to yield any significant environmental impacts, however, it is recommended that surplus material generated in the northern section be removed via that end of the alignment and the same for the south to reduce any disturbance to any one set of sensitive receivers.
184.108.40.206 However, waste management measures to control stockpiling, temporary storage and on-site transportation requirements, which could lead to short-term dust and visual impacts, particularly in Tung Chung and Cheung Sha where the majority of the sensitive receivers are located will be required. Recommended mitigation measures include:
¨ the Contractor shall identify a coordinator for the management of waste. The coordinator shall prepare and implement a Waste Management Plan which specifies procedures such as a ticketing system, to facilitate tracking of loads and to ensure that illegal disposal of wastes does not occur, and protocols for the maintenance of records of the quantities of wastes generated, recycled and disposed;
¨ training should be provided to workers about the concepts of site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling;
¨ all material shall be reused on site as far as practicable, including formwork plywood, topsoil and excavated material;
¨ good site practice shall be implemented to avoid waste generation and promote waste minimisation;
¨ any surplus material generated shall be sorted on site into construction and demolition (C&D) waste and the public fill fraction. Suitable provisions shall be included in the construction contract to ensure that the Contractor sorts and recycles waste;
¨ trees and vegetation shall be stripped prior to site clearance, chopped and compacted;
¨ excavated material shall be reused as close to the point of excavation and as soon after excavation as possible and directly transferred to the area deposition;
¨ the surplus excavated material from the northern sections of the alignment shall be exported via the Tung Chung end of the works area and all other material will be exported from site to the stockpile in Mui Wo, subject to consultation with the Public Fill Committee prior to construction;
¨ stockpiled material shall avoid vegetated areas where possible and be covered with tarpaulins;
¨ major stockpiled areas shall be sited outside of the country parks area and away from stream courses;
¨ stockpiling shall be kept to a minimum;
¨ stock piled materials shall be contained in a designated area down gradient from any stream, as far as possible, or up gradient with a suitably constructed barrier to reduce loss of materials to the stream;
¨ no fuel/oil shall be stored within the Country Park or water gathering grounds;
¨ no chemical wastes shall be stored in the water gathering grounds;
¨ no canteen facilities shall be located within the water gathering grounds;
¨ the Contractor shall comply with WSD’s General Conditions for Working within Water Gathering Grounds;
¨ no maintenance activities which may generate chemical wastes shall be undertaken in the water gathering grounds and
¨ excavated material in trucks shall be covered by tarpaulins to reduce the potential for spillage.
220.127.116.11 Measures to control general construction waste, chemical waste, general refuse and sewerage will also be required. EM&A in the form of the audit of the Contractor’s procedures, methods and waste management controls are recommended during the construction phase. Detailed specifications for the EM&A are provided in the EM&A Manual.
18.104.22.168 Key ecological resources have been identified in the study area through literature review and field surveys. These include designated nature conservation areas, habitats and species which are protected, rare, vulnerable to human disturbance or otherwise of conservation interest. While the alignment has been designed so far as practicable to minimise the impacts to these habitats and species, some impacts will occur. Some of the key habitats and species of concern which may be affected and for which varying degrees of mitigation will be required include:
¨ secondary woodland along the alignment;
¨ streams along the route;
¨ shrub Pavetta hongkongensis, orchids Acampe rigida and Liparis viridiflora and tree Artocarpus hypargyreus; and
¨ habitats of amphibians and reptiles along the route including the Romer’s Tree Frog.
22.214.171.124 However, the habitat loss has been minimised by restricting the footprint of the works and widening the road on-line as far as possible. In addition, impacts on key ecological streams have been avoided by the road crossing over these on structure and the Fong Yuen marsh has also been avoided by careful design of the permanent drainage system. Mitigation measures are required however and a summary of the mitigation and enhancement measures recommended to minimise predicted impacts are given below:
¨ control of site run-off to protect ecology of water courses, particularly important for the Tung Chung Stream and the Cheung Sha Stream;
¨ transplantation of the shrub Pavetta hongkongensis, orchids Acampe rigida and Liparis viridiflora and tree Artocarpus hypargyreus;
¨ special design of new culverts and culvert inlet and outlets for streams 19 and 21 (Figure 6.1) and culvert inlet and outlets for Stream 18;
¨ translocation of Hong Kong Newt, Lesser Spiny Frog and Romer’s Tree Frog from streams 15, 18, 19 and 21;
¨ scheduling of works in streams 15, 18, 19 and 21 to avoid the period April to June which is the key breeding period for fish, amphibians and odonates;
¨ translocation of Romer’s Tree Frog between Lung Tseng Tau and Shek Mun Kap;
¨ provision of water filled pots as habitats for the Romer's Tree Frog between Lung Tseng Tau and Shek Mun Kap;
¨ translocation of isolated population of Beijiang Thick-lipped Barb in Stream 15 to tributary of Tung Chung Stream;
¨ provision of slope surfaces at step channels for aquatic fauna to move up and down stream at the existing bridge at stream 15;
¨ provision of escape routes from drainage channels for amphibians;
¨ provision of wildlife tunnels for faunal transfer;
¨ compensatory planting to mitigate for vegetation loss; and
¨ reinstatement of land temporarily required during construction within 3 weeks of the areas being completed.
126.96.36.199 The proposed mitigation measures are considered adequate overall to fully mitigate all identified impacts. However, minor residual impacts on habitats are predicted based upon the fact that not all woodland habitat loss can be mitigated in the short term. Also, some residual impacts caused by the barrier effect of the road are expected but these will be minor in light of the recommendation to construct wildlife tunnels at certain locations along the road. All residual impacts are considered to be acceptable within the benefits of the scheme.
188.8.131.52 Due to the need to design translocation works in respect of the shrub Pavetta hongkongensis, orchids Acampe rigida and Liparis viridiflora and tree Artocarpus hypargyreus, Hong Kong Newt, Lesser Spiny Frog, Romer’s Tree Frog and Beijiang Thick-lipped Barb, EM&A in the form of a design specification audit has been recommended during the design phase. Design specification will also be required for the wildlife tunnels, specialised culvert design and amphibian escape ramp. In addition, audit of the specialist works as well as the implementation of the other mitigation measures during the construction phase will be undertaken. Operational phase EM&A during the first year of the operation of the project will also be carried out to monitor the establishment and success of the transplantation exercise. Detailed specifications for the EM&A are provided in the EM&A Manual.
184.108.40.206 The land forms of Lantau contribute significantly to its identity. Within the study area, lower slopes are generally gentle and soil-covered. These comprise loose material which is the result of landslides and ground slump. This is generally fairly unstable material. Upper slopes are generally steeper and more spectacular, comprising a topography of bare rock outcrop and boulder strewn hillsides resulting in an often dramatic and rugged appearance. In these upper valleys, the exposed location and the general instability of the soils has inhibited the development of vegetation resulting in soils of low fertility. Given their general abundance their sensitivity to change is considered to be low. In the more sheltered, low-lying coastal areas of Tung Chung Valley and in limited areas immediately above Cheung Sha Beach deeper, more fertile soils can be found resulting from the presence of dense woodland cover and formerly the long term farming of arable crops and rice paddies. These areas are increasingly rare in Hong Kong and are considered to be of medium sensitivity to change.
220.127.116.11 Large areas of riparian, secondary woodland exist in the more sheltered valleys. These are a significant element in defining the landscape character of Lantau Island. Extensive areas of plantation woodland have also been established on various hill slopes within the southern part of the study area as a result of re-planting works following hill fires.
18.104.22.168 The extensive use of retaining wall and use of structures along the alignment has reduced the degree of slope works and in addition, the road will be widened on-line as far as possible. Therefore, the landscape and visual impacts of the road have been minimised through careful design. Mitigation measures to minimise the extent of the remaining impacts include:
¨ minimising working areas as far as possible;
¨ protection and retention of existing natural rocky outcrops, slope profiles, topography and ridgeline,
¨ protection and retention of existing stream courses;
¨ protection and retention of existing secondary woodland, plantation woodland and tall shrub vegetation where possible;
¨ transplanting of trees which are of high amenity value and stand a good chance of successful reestablishment;
¨ topsoil stripped and stored for re-use in the construction of the soft landscape works;
¨ grass hydroseeding of slopes and disturbed areas with 3 weeks of being completed;
¨ planting of native shrub species on newly formed and upgraded roadside slopes and areas disturbed by the works to compensate for shrub vegetation lost during construction;
¨ planting of native woodland species on newly formed and upgraded roadside slopes and areas disturbed by the works to compensate for woodland vegetation lost during construction;
¨ infill planting of native trees in areas of existing low shrub adjacent to the road, to enhance ecological diversity; and
¨ tree and shrub planting to screen the road, to provide visual interest and to provide shade and shelter.
22.214.171.124 It is intended that the compensatory planting noted above will be able to recompense for the woodland and shrubland lost and to help re-establish the landscape pattern and reduce the visual impact of the road.
126.96.36.199 The large-scale open nature of the landscape of the study corridor, make the existing Tung Chung Road and the future improvement works to Tung Chung Road highly visible. Generally, the landscape mitigation measures seek to minimise potential visual impact of development, to screen sensitive views and to blend the new development into the surrounding landscape. However, in addition to those measures proposed to mitigate for landscape impacts, further specific mitigation measures for visual impacts include:
¨ sensitively designed site hoarding, where applicable;
¨ sensitive architectural and chromatic treatment of new road structures, elevated bridge structures, abutments, retaining walls; and
¨ sensitive architectural and chromatic treatment of noise barriers.
188.8.131.52 The alignment will be associated with negligible to moderate negative residual impacts on landscape resources and character at the opening Year. Visual impacts will tend to be less substantial and are likely to range from between negligible to slight negative. These can be reduced to acceptable levels with the implementation of the mitigation measures proposed, which should result mostly negligible but with one or two slight or moderate residual landscape impacts and very negligible to slight visual impacts by Year 10.
184.108.40.206 EM&A in the form of audit of the detailed landscape specifications has been recommended to be undertaken during the design phase to ensure that the recommendations of the EIA have been fully incorporated. In addition, audit of the landscaping works as well as the implementation of the other mitigation measures during the construction phase will be undertaken. Operational phase EM&A during the first year of the operation of the project will also be carried out to monitor the establishment and success of the compensatory planting. Detailed specifications for the EM&A are provided in the EM&A Manual.
220.127.116.11 While the Cheung Sha Water Treatment works is not a designated PHI, the proposed road falls within 500m of this facility. The risk for the study area of the Cheung Sha WTW are calculated for both the individual risk and societal risk in terms of PLL and FN curves, and the results have been assessed for both the construction and operation phases (2006 and 2021). The individual risk levels for the route imposed by the Cheung Sha WTW are below the HKRG limit of 10-5 per year, and are acceptable and all the FN curves are acceptable and so no mitigation is expected to be necessary for both the construction and operation phases.
18.104.22.168 The road link contributes less than 5% of the total risk for the surrounding population and thus, no significant increase in risk is observed resulting from the development of the new Tung Chung Road. Overall, the risk for the road is low and acceptable.
22.214.171.124 Impacts on the potential archaeological features in the study area are associated solely with the construction phase of the project, but the historical buildings may also be affected by operation of the project. The potential for impacts, and the lack of historical and archaeological data from within the study area, dictated that site investigations be implemented. The field assessment was divided into archaeological site surveys and the assessment of historical buildings and structures.
126.96.36.199 The archaeological field evaluation, comprising walkover surveys, auger and test pit excavation. The test pits in Cheung Sha revealed the presence of former agricultural terraces and the three test pits conducted to the east of Tung Chung Road all contained historical material from the Qing dynasty. Based upon the distance from the alignment in Cheung Sha and the fact that the material found in Tung Chung does not represent a significant archaeological deposit, no mitigation measures are required.
188.8.131.52 The historical buildings survey identified and recorded 23 structures in the study area. It was determined that the proposed alignment has been refined to ensure that it will not directly impact on any historical building or structure. However, the impacts to be assessed for the 23 recorded structures are of a visual nature. The distance from the development will provide a sufficient buffer zone during the construction phase for these structures. As the development consists of the improvement to an existing road, there will be no new adverse visual impacts associated with the proposed project during the operational phase. However, based on the findings of the HIA the following mitigation measures are recommended:
¨ a shrine in Lung Tseng Tau lies approximately 10 metres from the alignment. The shrine should be left in situ. During the construction phase, if the shrine falls within the works area of the project a protective barrier such as a metal fence should be erected around it; and
¨ the Fong Yuen nunnery compound lies at a minimum distance of 50 metres from the road alignment and the following mitigation is recommended:
- the 50 metre wooded buffer zone between the road and the nunnery should be retained to maintain the existing screening of the compound from the road during the construction and operational phases of the project;
- planting of foliage along the cycle path in the vicinity of the monastery in order to maintain the existing environment; and
- during construction of the cycle path, the main building should be fenced off and kept separate from the works area.
184.108.40.206 In light of the need for mitigation measures to protect the shrine in Lung Tseng Tau and the Fong Yuen Nunnery, EM&A during the construction period is recommended. This will ensure that the mitigation measures and the surveys are implemented.
220.127.116.11 In accordance with the EIA, EM&A procedures are required during the design, construction and operational phases of the project implementation. The EM&A works during the design phase shall comprise an iterative audit process of specific design elements. The specifications for certain ecological and landscape mitigation measures recommended by the EIA will be required to be designed during the detailed design phase of the project.
18.104.22.168 During the construction and operational phases, the EM&A requirements are divided into environmental monitoring and/or project auditing in the form of site inspection and supervision. Environmental monitoring and audit for dust, noise and water quality during the construction phase is recommended in order to ensure all proposed mitigation measures are implemented and effective. All three of these parameters will also be subject to audit through site supervision.
22.214.171.124 Site supervision and procedures audit will be required during the construction phase to ensure the proper handling, storage, transportation and disposal of the various waste arisings from the project. Audit of the implementation of the design elements and mitigation measures to avoid ecological, landscape and visual and heritage impacts have also been recommended by the EIA, and thus, monitoring in the form of regular site inspections shall also be required to ensure mitigation measures are being implemented and are effective. EM&A for both ecology and landscape and visual resources will extend through the construction phase and into the operational phase to ensure landscape and ecological planting/replanting has been effective.
126.96.36.199 Operational noise monitoring shall be undertaken during the first year, in months 6 and 12, of the operation of the project to assess the effectiveness of the direct noise mitigation measures recommended by the EIA.
188.8.131.52 Full details and specifications for the recommended EM&A works are provided in the EM&A Manual.
184.108.40.206 There is only one key interface with the proposed improved Tung Chung Road, situated at the northern end of its alignment, namely the proposed development in Tung Chung and Tai Ho. The development in Tung Chung is being assessed under the Remaining Development in Tung Chung and Tai Ho Comprehensive Feasibility Study (CFS) currently being conducted by the Territory Development Department. The development proposals of relevance to this study involve the development of the Tung Chung Valley.
220.127.116.11 The assessment of cumulative impacts includes air quality, noise, water quality, waste, ecological factors and landscape and visual impacts during both the construction and operational phases as appropriate.
18.104.22.168 The assessment has concluded that few cumulative impacts will occur based upon the implementation of the two projects. Sufficient mitigation measures to reduce any impacts to within acceptable levels have been recommended for both the CFS and the improved Tung Chung Road and additional mitigation measures are not considered to be required.
22.214.171.124 Cumulative noise impacts are possible during permanent noise barrier construction in Tung Chung for the Tung Chung Road and either road works or site development for the Tung Chung Valley project. Cumulative impacts can be avoided by the careful scheduling of the works which would prevent noisy equipment working simultaneously.
126.96.36.199 Impacts at a proposed primary school adjacent to the Tung Chung Road are predicted with the main noise contribution being from the section of the improved Tung Chung Road which will be improved by Territory Development Department. Notwithstanding, a 4m landscaped earth bund between the road and the proposed school site has been proposed to protect the school from road traffic noise. The bund is sufficient to reduce noise levels to within the 65dB(A) limit for the school.
188.8.131.52 The design of the proposed road link has been optimised to minimise the extent and magnitude of environmental impacts, particularly the loss of habitat by minimising the footprint of the works as far as possible. Also, retaining walls have been used extensively to minimise the extent of the cut slopes and bridges have been used to traverse the key ecologically sensitive streams and key habitats such as the Fong Yuen Marsh have been avoided.
184.108.40.206 Where, the implementation of the new road will result in some impacts, a comprehensive range of mitigation measures has been recommended to reduce these impacts to acceptable levels. Apart from the mitigation of direct impacts, it is worth noting that some of these measures, will not only mitigate impacts, but will also enhance the existing environmental conditions as follows:
¨ the incorporation of wildlife tunnels under the at-grade sections of road;
¨ sensitive design of culverts and culvert inlets and outlets to allow fish and other aquatic faunal access;
¨ provision of slope surfaces at step channels for aquatic fauna to move up and down stream at the existing bridge at stream 15;
¨ provision of escape ramps in drainage channels for amphibians;
¨ provision of water filled pots as habitats for the Romer's Tree Frog; and
¨ the relocation of key floral and faunal species.
220.127.116.11 In addition, the proposed remedial works to the existing slopes using bio-engineering techniques (ie, hydroseeding instead of spray applied concrete) will enhance the existing slopes, resulting in areas of higher ecological value.
18.104.22.168 Furthermore, the proposed special permanent drainage systems will avoid carriageway runoff from being discharged into both the Tung Chung and Cheung Sha streams and also the water gathering grounds. This is will be an improvement on the existing conditions, whereby carriageway runoff is discharged directly into the small streams, watercourses and hillsides directly below the existing road.
22.214.171.124 Overall, the environmental impacts predicted for all environmental parameters can be reduced to acceptable levels with the implementation of the recommended mitigation measures. Low residual impacts on habitats are predicted based upon the fact that not all habitat loss can be mitigated in the short term. Residual impacts caused by the barrier effect of the road are expected but these will be minor in light of the recommendation to construct wildlife tunnels at at-grade sections of the road.
126.96.36.199 Residual landscape and visual residual impacts will occur but the landscaping proposals will fully mitigate for the loss in the long term. All the residual impacts of the project are considered acceptable within the overall scope and benefits of the project.