11                 Conclusion

11.1            Introduction

11.1.1      The Project is a designated project in accordance with Item A1, Part 1 of Schedule 2 of the EIAO, as there would be a major improvement to existing Tuen Mun Road Town Centre Section which is classified as a Primary Distributor.

11.1.2      This EIA Report included an assessment on the potential environmental impacts for the construction and operation of the Project, taking into account the potential cumulative impact from Reconstruction and Improvement of Tuen Mun Road-Sam Shing Hui Section, Contract No.HY/2008/11.  Specific mitigation measures requirements for the Project, as well as an environmental monitoring and auditing programme, have been developed in the study.  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 11.2.

11.2            Environmental Outcome

11.2.1      The major sensitive areas within the study area include residential buildings, commercial buildings, recreational areas and educational institutions.  With the implementation of the proposed mitigation measures, no adverse environmental impacts would be expected at the air, noise and water quality sensitive receivers during both construction and operational phases.  A summary of the key environmental outcomes arising from the EIA study and benefits of the environmental protection measures recommended are presented in Table 11.1 below.

Table 11.1        Summary of Key Environmental Outcomes/ Benefits

Issue

Environmental Outcomes/Benefits

The Project

Requirements:

·         Widening the following sections of Tuen Mun Road Town Centre Section (TMRTCS) from dual 2-lane carriageway to dual 3-lane carriageway

Ø             Wong Chu Road Section, (from Wong Chu Road Interchange to Tuen Hing Road); and

Ø             Tuen Mun Town Plaza Section, (from Yan Oi Town Square to Tuen Hing Road).

Benefits

·         The Project can relieve the traffic congestion at the TMRTCS between Yan Oi Town Square in the north and Wong Chu Road in the south

Potential Sequences without the Project

·         Without the Project, there would be traffic capacity concern for TMRTCS.  This road section may become a bottleneck due to the natural traffic growth of TMR and the increased traffic bring about by HK-SWC and the Deep Bay Link.

·         Due to the possible severe traffic congestion at TMRTCS, there would be a consequential adverse air quality impacts to the nearby ASRs as the vehicles are in idling condition during traffic congestion.

 

Development Alternatives

·         Comparing with the “Tunnel” option, the “Dual 3-lane widening from Yan Oi Town Square to Wong Chi Road” is a direct method to solve the traffic congestion problem in view of the traffic benefits, social benefits, engineering feasibility, land requirement, programme and cost.

·         In view of environmental aspects, widening of existing road section would pose relatively less environmental impacts to the surrounding environment.  The Dual 3-lane widening option would involve less excavation quantities, no portal exhaust as required by tunnel, less construction traffic and smaller construction area.

Construction Noise

Impact/Problem

·         Unmitigated cumulative construction noise levels: 66 dB(A) to 91 dB(A).

Key environmental problem avoided:

·         Recommended mitigation measures: adopting quiet construction plant, movable noise barriers, scheduling of construction activities and implementing good site practices.

Environmental benefits of environmental protection measures recommended & Environmentally sensitive areas protected:

·         Under mitigated scenario, all representative NSRs would be protected to comply with the daytime construction noise standard as set out in the EIAO-TM, except 5 NSRs of educational institutions, namely CMA, LWF, LCKP, LCK and CSBS would exceed the noise criteria during examination periods.  The contractor would be suggested to liaise with all relevant schools to check out their examination periods and activities in the beginning of the works programme.  The noise impacts would be alleviated by good planning and arrangement of works and providing sufficient mitigation plans from the contractor.

Road Traffic Noise

Impact/Problem

·         Unmitigated noise levels: 61 dB(A) to 85 dB(A).

Key environmental problem avoided:

·         Recommended mitigation measures as shown in Figures 3.3A to 3.3C.

Environmental benefits of environmental protection measures recommended & Environmentally sensitive areas protected:

·         Mitigated noise levels of NSRs along widened Tuen Mun Road Town Centre Section: 52 dB(A) to 76 dB(A). The ‘New’ road noise contributions to the overall noise levels at all representative NSRs (except TFH, CLFY2, CLFY5, CLFY6, HKG, TTP, KFG1A and KFG1B) would be below the relevant noise criteria, though the overall noise levels at some of the NSRs would still exceed the relevant noise criteria. Such exceedances are due to the existing roads.



·         Due to site constraint, noise enclosure is technically infeasible to be built to further alleviate the noise impacts at TFH, CLFY2, CLFY3, CLFY5, CLFY6, HKG, TTP, JCP, HG, KFG1A and KFG1B. Eligibility test is conducted showing that all the NSRs are not eligible for provision of noise insulation works.

Construction Air Quality

Impact/Problem

·         Potential air quality impacts are dust nuisance.

Key environmental problem avoided:

·         Mitigation measures: implement the Air Pollution Control (Construction Dust) Regulation and good site practices.

Environmental benefits of environmental protection measures recommended:

·         No adverse air quality impacts are anticipated.

Operational Air Quality

Impact/Problem

·         No adverse traffic emission impacts are anticipated at the existing and future ASRs.

Construction Water Quality

Impact/Problem

·         General construction activities associated with the construction of the Project could lead to site runoff.

Key environmental problem avoided:

·         All of the recommended mitigation measures are implemented and all construction site / work area discharges comply with the TM-DSS standards.

Environmental benefits of environmental protection measures recommended:

·         No unacceptable residual water quality impacts are expected during the construction of the proposed infrastructure

Operational Water Quality

Impact/Problem

Adverse water quality impacts associated with the operation of the Project are not expected at the water sensitive receivers within the study area.  Thus, there will be no residual impact associated with the operation of the Project.

Waste Management

Impact/Problem

·         Wastes generated by construction activities: general refuse from the workforce, chemical waste from plant and equipment maintenance, and C&D material from excavation works and the demolition of existing structures.

Environmentally friendly designs recommended:

·         5,850 m3 of inert C&D material (public fill) to be disposed to public fill reception facilities for other beneficial uses.

·         3,000 m3 of inert C&D material to be reused on-site.


Environmental benefits of environmental protection measures recommended:

·         With the implementation of the recommended mitigation measures and practices for the handling, transportation and disposal of the identified waste arisings, no adverse environmental impacts are expected.

Ecology

Impact/Problem & Environmentally friendly designs recommended

·         The proposed construction works would only be conducted in the developed area.  No direct impact on ecological important habitats, such as woodland habitat, would be resulted from the proposed works.

·         The removal of roadside plantation of common species within the proposed site area would be compensated by compensatory planting.

·         Disturbance impacts to habitats and associated communities adjacent to the proposed site area would be resulted due to the construction works. Wildlife within the proposed site area and the adjacent woodland also adapted to high levels of human disturbance, heavy traffic flow and traffic noise, thus the disturbance impact is considered low.

·         Impacts resulting from improper dumping of construction materials/wastes and deposition of dust on vegetation adjacent to site areas would be resulted in the construction phase. The potential impacts can be avoided and minimized to acceptable levels through the implementation of standard good site practice.

·         Sediment and runoff if uncontrolled, would carry pollutants into Tuen Mun River Channel. With the implementation of adequate construction site drainage and provision of sediment removal facilities, it is anticipated that unacceptable water quality impacts on the River Channel would not be arisen.

·         With the implementation of effective mitigation measures, construction phase noise disturbance would be minimised. In the worse-case scenario, alternative similar foraging habitat for Little Egret is relatively common along Tuen Mun River Channel. With the implementation of adequate construction site drainage and provision of sediment removal facilities, unacceptable water quality impacts on the River Channel would not be arisen. Overall, the potential impact to Little Egret is considered low.

Environmentally friendly designs recommended:

·         Noise barrier with transparent panels implemented in the operation phase would cause potential bird mortality. As the transparent panels would appear invisible to birds or mirrors the facing landscape, birds are unable to recognize them as physical barriers. With bird-friendly design of noise barriers, such as using non-glaring and tinted materials, putting falcon stickers on the transparent panels, bird collision due to the noise barrier would be minimized.

 

 

Environmental benefits of environmental protection measures recommended:

·         the bird collision due to the noise barrier would be minimized.

Landscape and Visual

Impact/Problem

·         Approximate 860 trees (out of approximately 1000 existing trees) will be affected by the construction of traffic improvement works to Tuen Mun Road and the proposed noise barriers and enclosures. Approximately 50% of the affected trees will be transplanted and approximately 50% will be felled.

·         A number of open space and planting areas in Tsing Sin Playground, Yan Oi Tong Circuit, On Tin Estate and Tsing Hoi Playground will be alienated by the temporary works during the construction phase. Many of the affected areas during the construction will be reinstated after the construction work.  Approximate 350sqm of open space area (12%) will be permanently lost in Tsing Hoi Playground and approximate 700sqm of open space area (14%) will be permanently lost in Tsing Sin Playground due to the road works.  

·         There will be visual impact due to the provision of noise barriers and enclosures.

Environmentally friendly designs recommended

·         Heavy standard and standard trees will be planted at 1:1 ratio in terms of quantity to compensate for the felled trees. 

·         Vertical greening panels with design theme in area with adequate sunlight and maintenance access to reflect the local context is proposed.  The green roof for the noise enclosure have been fully explored and proposed where space for maintenance access is allowed.

Environmental benefits of environmental protection measures recommended:

·           With the implementation of the mitigation measures such as the provision of approximate 11,000sqm vertical greening with thematic treatment along the noise barriers and enclosures facade and approximate 20,000sqm of green roof proposed on the enclosure, and the implementation of the Tuen Mun District Planting Scheme, it is believed that the landscape and visual impact will be brought down to a marginally acceptable level after 10 years.

Land Contamination

Impact/Problem

·         No potential land contamination concern was identified within the Project boundary. However indirect concern was identified at the existing petrol filling station located outside the assessment area approximately 2m from the boundary.

Key environmental problem avoided:

·         Preliminary land contamination survey was proposed to better understand the baseline condition of the underground media which might have impacted by the operation at the off-site petrol filling station.

Environmental benefits of environmental protection measures recommended:

·         No adverse land contamination impacts are anticipated if the proposed protection measures and necessary remediation actions are carried out.

 

11.3            Noise

Construction Phase

11.3.1      This assessment has predicted the construction noise impacts of the Project during normal daytime working hours.  With the use of quiet PME and movable barriers, and scheduling of construction activities, the noise levels at all representative NSRs except some educational institutes during examination period would comply with the construction noise standard.  The predicted construction noise levels at NSR CMA, LWF, LCK, LCKP and CSBS would exceed the noise standard for schools during examination periods if tree felling, noise barriers/enclosures foundation, slope works and landscape works undertake in the vicinity of these educational institutes.  It is recommended that the Contractor liaise with all affected schools to check out their examination periods in the beginning of the work programme. The noise impact would be alleviated by good planning and proper arrangement of noisy construction activities.  

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

Operation Phase

11.3.3      The potential road traffic noise impacts have been assessed based on the worst case traffic flows in 2025.  The noise levels at some NSRs are predicted to exceed the EIA-TM traffic noise criteria due to both ‘New’ road and existing roads. As a result, direct mitigation measures have been proposed to mitigate the noise impacts at the NSRs where ‘New’ road noise contributions to the overall noise levels would be more than 1.0 dB(A).

11.3.4      With the proposed noise mitigation measures in place, the ‘New’ road noise contributions to the overall noise levels at all representative NSRs would be less than 1.0 dB(A), except those mentioned in the following paragraphs (Section 11.3.5).  Furthermore, the ‘New’ road noise levels would all be below the relevant noise criteria, though the overall noise levels at some of the NSRs would still exceed the relevant noise criteria.  However, it should be noted that such noise exceedances at the representative NSRs are caused by the existing roads.

11.3.5      Due to site constraint, noise enclosures could not be built to further alleviate the noise impacts at NSRs TFH, CLFY2, CLFY3, CLFY5, CLFY6, HKG, TTP, JCP, HG, KFG1A and KFG1B. Eligibility test is conducted to assess the eligibility of these NSRs for provision of noise insulation works (NIW). The test results show that all the NSRs are not eligible for provision of NIW.

11.3.6      Monitoring of road traffic noise is recommended to verify the effectiveness of the mitigation scheme during the first year after road opening.

11.4            Air Quality

Construction Phase

11.4.1      In view of limited scale of construction area, adverse dust impact at the ASRs would not be expected from the Project.  Nevertheless, appropriate dust control and suppression measures as stipulated in the Air Pollution Control (Construction Dust) Regulation should be implemented to minimise any potential dust impact.

Operation Phase

11.4.2      The potential impacts arising from the background pollutant levels within and adjacent to the Project site, vehicle emissions from open road networks and the implementation of roadside noise barriers/enclosures are assessed.  Results showed that the predicted air quality at the ASRs would comply with the AQOs.  No mitigation measures are required.

11.5            Water Quality

Construction Phase

11.5.1      Water quality impacts from land-based construction, including road works and construction of noise barriers / enclosures, are associated with the surface runoff, effluent discharge from the site, and sewage from on-site construction workers.  Impacts can be controlled to comply with the WPCO standards by implementing the recommended mitigation measures.  No unacceptable residual water quality impact would be anticipated. 

Operation Phase

11.5.2      It is considered that impacts resulting from the operation of the Project, in terms of water quality, will be minimal provided that the TMRTCS is designed with adequate drainage system.

11.6            Waste Management

11.6.1      Wastes generated by the construction activities are likely to include site clearance waste, C&D materials, chemical waste from the maintenance of construction plant and equipments and general refuse from the workforce.  Provided that these identified wastes arising are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts would not be expected during the construction phase.

11.7            Ecology

11.7.1      No direct impact on ecologically important habitats would be resulted from the proposed works, which would take up about 12ha of developed area.  The proposed construction works would only occur within the developed area, which is of low ecological value and is comprised of a section of Tuen Mun Road from San Hui Sitting-out Area to Kam Fai Garden.  The developed area supports no floral and faunal species of conservation importance.  The impact on habitat loss is considered to be low.

11.7.2      Little Egret (Egretta garzetta), a species of conservation interest, has adopted to tolerate a certain level of pollution and disturbance.  It was recorded at the egretry and along the embankment of Tuen Mun River Channel within the Study Area.  Construction and operation of the Project are not expected to have significant impact on the egretry and bird population with the implementation of the proposed mitigation measures.

11.7.3      The impact of loss of vegetation through removal of roadside plantation of common species within the proposed Works Area is not considered to be ecologically significant.  The loss would be compensated by compensatory planting or transplantation.

11.7.4      Bird collision with the proposed construction of permanent noise barrier could result in bird mortality.  With the combination of the suggested measures for the design of noise barrier, impacts on bird population should be minimised. Bird collision due to the noise barrier would be minimized.

11.7.5      Considering the small scale of proposed construction works, highly disturbed nature of the Study Area, and with the proposed mitigation measures in place, including noise mitigation measures and good site practice, no adverse ecological impacts from the construction and operation of the Project is expected.

11.8            Landscape and Visual

11.8.1      The source of landscape and visual impact is mainly due to the provision of noise barriers and enclosures for the road widening works. Under the EIAO, noise barriers and enclosures must be provided to mitigate the traffic noise. Such provisions are supported by the Tuen Mun District Council because the current noise level due to the existing traffic at TMRTC is high. The provision of noise enclosures will reduce the noise level to satisfy current standard. The relevant meetings with TMDC were held on 14 September 2007, 21 September 2007, 19 February 2008, 14 March 2008 and 21 November 2008.

11.8.2      Given the tight space within the Tuen Mun Road, the additional lane and provision of noise barriers and enclosures will cause significant impact on existing trees along Tuen Mun Road and such impact is unavoidable. The impact on trees has been consulted with TMDC and comments on tree treatment proposals will be incorporated in detailed design of the Project. Approximate 860 trees (out of approximately 1000 existing trees) will be affected by the construction of traffic improvement works to Tuen Mun Road and the proposed noise barriers and enclosures. Approximately 50% of the affected trees will be transplanted and approximately 50% will be felled. Many of the affected trees are mature. None of these are LCSD Champion Trees or Registered Old and Valuable Trees. There are no rare species or endangered species but common species. Opportunities for tree compensation within the site boundary and outside the site boundary within Tuen Mun Town Centre have been fully explored and incorporated in the mitigation measures as much as possible. Heavy standard and standard trees will be planted to compensate for the felled trees at 1:1 ratio in terms of quantity. Tree planting is proposed within Tuen Mun Town Centre as soon as possible and practical to mitigate the loss of greenery during construction and operation of the Project.

11.8.3      A number of open space and planting areas in Tsing Sin Park, Yan Oi Tong Circuit, On Tin Estate and Tsing Hoi Playground will be alienated by the temporary works during the construction phase. Many of the affected areas during the construction will be reinstated after the construction work. Approximate 350sqm of open space area (12%) will be permanently lost in Tsing Hoi Playground and approximate 700sqm of open space area (14%) will be permanently lost in Tsing Sin Park due to the road works. The residual impact on these open spaces is slight as only a small percentage of the overall park or playground will be affected.

11.8.4      To minimize the visual impact due to the provision of noise barriers and enclosures, an integrated landscape and engineering design approach has been adopted. Design measures have been incorporated to minimize the visual bulkiness of the structure. Vertical greening panels with design theme in area with adequate sunlight and maintenance access to reflect the local context are proposed. The green roof for the noise enclosure has been fully explored and proposed where space for maintenance access is allowed. There are a number of design options considered for the green roof, vertical facade treatment and colour scheme for the noise barriers and enclosures. Based on the assessments and considerations documented in the report, the preferred overall landscape and aesthetic design treatments on the noise barriers and enclosures is recommended as the proposed design scheme for the landscape and visual impact assessment.

11.8.5      Having implementation of the proposed mitigation measures as per the preferred landscape and aesthetic design treatment, unavoidably, there will still be moderate residual visual impact on adjacent Visual Sensitive Receivers (VSR) as well as the traveling VSRs along Tuen Mun Road due to the blockage of views by the noise enclosures and barriers and loss of existing greenery. However, with the thematic design treatment on the vertical facade and green roof treatment with pattern, it is considered that the residual visual impact has been reduced to a marginally acceptable level.

11.8.6      In summary, the provision of the noise barriers and enclosures for the road widening works is a mandatory requirement under the EIAO and is supported by the Tuen Mun District Council. With the implementation of the mitigation measures, including the provision of approximate 11,000sqm vertical green panels with thematic treatment along the noise barriers and enclosures facade, the provision of approximate 20,000sqm green roof and the implementation of Tuen Mun District Planting Scheme, it is believed that the landscape and visual impact will be brought down to a marginally acceptable level after 10 years.

11.9            Land Contamination

11.9.1      Based on the findings of site inspection, no potential land contamination concern was found within the Project boundary. However, the existing petrol filling station located outside the assessment area, near the junction of Tuen Hing Street and TMR was identified as an indirect potential land contamination concern. A preliminary land contamination survey is therefore proposed within boundary of the assessment area at the immediate down gradient of the petrol filling station to determine the baseline soil and groundwater conditions. Mitigation measures have also been proposed for handling of the potential contaminated materials as general measures.

11.9.2      No adverse residual impact in respect of land contamination is anticipated if necessary remediation is carried out at the contaminated areas confirmed by site investigation.

11.10        Environmental Monitoring and Audit

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

11.11        Overall Conclusion

11.11.1   The EIA has been conducted based on the currently available information.  The findings of this EIA have provided information on the nature and extent of environmental impacts arising from construction and operation of the Project.  The EIA has, where appropriate, identified mitigation measures to ensure compliance with environmental legislation and standards.

11.11.2   In conclusion, the Project would generally comply with the environmental standards and legislation with implementation of the proposed mitigation measures during the construction and operational stages.  This EIA has also demonstrated the general acceptability of the residual impacts and the population and environmentally sensitive resources in the vicinity of the site would be protected.  Environmental monitoring and audit mechanisms have been recommended for construction and operation of the Project, where necessary, to verify the effectiveness of the recommended mitigation measures.