Plan
for Review of Use of
New Low
Noise Road Surfacing Material(s)
for Tung
Chung New Town Extension (West)
(EP No.
EP-519/2016)
September
2022
1.
Project Description
The
development of Tung Chung New Town Extension (TCNTE), comprising Tung Chung
East (TCE) and Tung Chung West (TCW), is a mega-scale and complex project
aiming to provide land to meet the future housing economic and social
development needs of Hong Kong. Due to the fact that
the proposed works are geographically separated, the implementation of
mega-scale Project is divided into two packages, namely TCE and TCW
respectively. In accordance with the tight delivery programme, the Project will
be implemented in phases under separate contracts for the developments of TCE
and TCW. This Plan only covers the
details of the use of new low noise road surfacing material(s) for Tung Chung
West (TCW). For the review in Tung Chung East (TCE) area, if applicable, it
will be covered by separate submission(s).
2. Scope
of Works for Tung Chung New Town Extension
The
Tung Chung New Town Extension project (the Project) comprises the following
elements:
(i)
reclamation
of the seabed by a non-dredged method at TCE to form a total of about 130
hectares of land;
(ii)
construction
of about 4.9 kilometers of seawalls, with an
eco-shoreline, three drainage box culvert outfalls, three circulation drains
and a seawater intake at TCE;
(iii)
provision
of infrastructure for Tung Chung Area 58, including construction of a single
two-lane road with a footpath and the associated utility works;
(iv)
site
formation works at TCW;
(v)
construction
of the River Park including a visitor centre at TCW;
(vi)
construction
of proposed open space;
(vii)
construction
of sustainable urban drainage systems at TCW;
(viii)
construction
of roads, footpaths, cycle tracks and the associated junction / road
improvement works;
(ix)
engineering
infrastructure works covering drainage, sewerage, waterworks (including a fresh water service reservoir, a salt water service
reservoir and a salt water pumping station), common utility tunnels and
landscaping works; and
(x)
implementation
of environmental mitigation measures and environmental monitoring and audit
programme for the works.
3. Implementation
Programme
The
Contract No NL/2020/05 – Tung Chung New Town Extension – Site Formation and
Infrastructure Works at Ma Wan Chung (i.e. Contract 5)
at TCW has been awarded in May 2021 and is scheduled for completion in 2025.
The main contractor for Contract No. NL/2020/05 is Build King – Richwell Civil Joint Venture (BKRCJV).
The
Contract No NL/2020/06 – Tung Chung New Town Extension – Site Formation and
Infrastructure Works at Tung Chung Valley, Phase 1 (i.e.
Contract 6) at TCW has been awarded in May 2021 and is scheduled for completion
in 2025. The main contractor for Contract No. NL/2020/06 is China Railway Group
Limited (CREC).
The
detailed design for the first phase of site formation and infrastructure works
at TCE and TCW (First Phase development) has been completed, while the detailed
design for the remaining phase of site formation and infrastructures works is
in progress.
4. Submission
under EP
In
view that only Contract 6 has construction of roadworks with the application of
low noise road surfacing materials in TCW, this submission is prepared based on
the latest information of Contract 6 according to the relevant requirements
contained in the EM&A Manual, EIA Report and EP. Please find the enclosed
Plan for Review of Use of New Low Noise Road Surfacing Material(s) below for
TCW. This submission will be
revised if there is any update of the information.
1.2 ENHANCEMENT OF DEVELOPMENT INTENSITY OF PUBLIC HOUSING SITES
2 Application of New LNRS Materials
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1 introduction
The Plan is prepared by China Railway Engineering Group Limited (known as CREC) in accordance with the Condition 2.23 of the Environmental Permit No. EP-519/2016 dated 09/08/2016.
This Plan only covers the details of the use of new low noise road surfacing material(s) (LNRS materials) for Tung Chung West (TCW). For the review in Tung Chung East (TCE) area, if applicable, it will be covered by separate submission(s). This Plan will be revised if there is any update of the information.
1.1 PROJECT BACKGROUND
1.1.1 An Environmental Impact Assessment (EIA) for Tung Chung New Town Extension (TCNTE) was prepared during the P&E (Planning and Engineering) Study and submitted under the Environmental Impact Assessment Ordinance (EIAO) in December 2015, and was subsequently approved in April 2016 (AEIAR-196/2016). An Environmental Permit (EP) was also issued by Director of Environmental Protection (DEP) in August 2016 (EP-519/2016). Civil Engineering and Development Department (CEDD) has then appointed Arup to undertake the Tung Chung New Town Extension (West) – Design and Construction under the Agreement No. CE 70/2015 (CE) (hereafter named as the Project).
1.1.2 According to the approved EIA Report (AEIAR-196/2016) (Section 4.5.4), the mitigation measures for road traffic noise for Tung Chung West (TCW) is given in Appendix A. Those mitigation measures include the following.
· Some residential buildings at Area 60 with façade with no openable window;
· Some residential buildings at Area 60 with architectural fins of about 1.5m long;
· Residential building at Area 42 with façade with no openable window;
· Low Noise Road Surfacing (LNRS) materials along Chung Mun Road of approx. 210m long, Road L29 (i.e. Road L24 as stated in the EIA Report) of approx. 160m long and Road L30 of approx. 160m long;
· 4m high school boundary wall of approx. 50m long for the school at Mun Tung Estate; and
· 5m high vertical barrier of approx. 120m long with 3m cantilevered arm at 45° at the junction between Chung Mun Road and Road L29.
1.1.3 The approved EIA Report had recommended road traffic noise mitigation measures along Chung Mun Road, Road L29 and Road L30. During the detailed design of the Project, a review on the traffic noise mitigation measures recommended in the approved EIA Report has been conducted. After the discussion on the LNRS materials maintenance arrangement during the road traffic noise assessment and meetings among CEDD, EPD, HyD & Planning Department (PlanD) on 25 March 2020, a conclusion was made that full extent of LNRS materials along Chung Mun Road and an exclusion of 30m LNRS materials at the run-in/out to Area 42 at Road L30 would be adopted (Please refer to Figure 1.1). A separate noise assessment conducted with the exclusion of 30m LNRS materials at the run-in/out to Area 42 at Road L30 and the same extent of LNRS materials along Chung Mun Road and Road L29 stated in the approved EIA demonstrated that road traffic noise levels at noise sensitive receivers would comply with relevant noise criteria (presented in "Technical Note on Revised Mitigation Measures for Road Traffic Noise (May 2020))".
1.1.4 According to the approved EIA Report, Chung Mun Road as a district distributor road is a designated project under Item A.1 of Schedule 2 (Part I) under the EIAO. According to the EP’s condition 2.33, the road traffic noise mitigation measures on Chung Mun Road are given in Figure 2 of that EP as given in Appendix B.
1.1.5 It should be noted that the approved EIA Report had recommended road traffic noise mitigation measures along Road L29 and Road L30 as well. However, since Road L29 and Road L30 are not district distributors and hence they are not DP, the mitigation measures for Road L29 and Road L30 are not included in the EP. Nevertheless, those mitigation measures would still need to be implemented.
1.2 ENHANCEMENT OF DEVELOPMENT INTENSITY OF PUBLIC HOUSING SITES
1.2.1 An increase of the Gross Floor Area (GFA), flat number and population of public housing sites (Areas 23, 42 & 46) was proposed by Housing Department (HD) according to the requirements on the Legislative Council Brief "Enhancement of the Development Intensity of Public Housing Sites". According to the planning parameter provided in July 2019, the total population for TCW housing sites (Areas 23, 42 & 46) of Scenario 2 (B2) and Scenario 3 (L) are 27,828 and 31,454 respectively.
1.2.2 Following the Executive Council’s approval, the Government would enhance the development intensity of public housing sites such that their maximum domestic plot ratio will be allowed to increase beyond the current 20% cap by up to 10% points (i.e. maximum 30% in total) where their technical feasibility permits and with the approval of the Town Planning Board as appropriate.
1.2.3 On 9 September 2019, CEDD issued an additional Services to Arup to investigate the feasibility to enhance the development intensity of public housing sites in TCW.
1.2.4 In accordance with the prevailing policy on enhancing the development intensity of public housing sites, CEDD has explored the feasibility to suitably increase the development intensity of the TCNTE to meet the increasing pressure to address the public housing shortage. Having considered the existing development characters and intensities in TCNTE, a scenario to increase the development intensity of public housing sites is proposed ("Scenario 2 (B2)"), in which the development intensity of public housing sites (Areas 23, 42 & 46) is to be increased based on full utilisation of site area, the permitted plot ratio (P/R), site area, domestic and non-domestic GFA permitted on the approved OZP, reduced average flat size, population-per-flat, flat number, population proposed by Housing Department (HD).
1.2.5 Subject to the technical feasibility of development parameters under "Scenario 2 (B2)", further increase in domestic plot ratio for public housing development in Areas 23, 42 & 46, GFA, flat number and population of public housing sites proposed by HD in accordance with the 2018 ExCo Policy on "Enhancement of the Development Intensity of Public Housing Sites", i.e. the maximum domestic PR of the public housing sites will be allowed to increase beyond the current 20% cap by up to 10% points (maximum 30% in total or percentage allowed to increase), might be explored. This further increase in domestic PR is defined as "Scenario 3 (L)".
1.3 PURPOSE OF THIS PLAN
1.3.1 The purpose of this Plan is to review the use of new low noise road surfacing material(s) as a noise mitigation measure in TCW in accordance with Condition 2.23 of the Environmental Permit No. EP-519/2016 taking into consideration of the development in the area as mentioned in the EIA Report.
1.3.2 According to Condition 2.23 of EP, this Plan should include at least the following information:
· the environmental benefits, including but not limited to reduction of traffic noise impacts, of adopting the new low noise road surfacing material(s) as an alternative noise mitigation measure to the material(s) currently in use;
· the extent and locations of providing the new road surfacing material(s) for the roadworks covered by this Permit with justifications; and
· reduction
in traffic noise impacts at specific sensitive receivers and minimization of
the extent of noise barriers for the roadworks covered by this Permit as a
resulting of applying the new road surfacing material(s).
2 Application of New LNRS Materials
2.1 GENERAL
2.1.1 According to the "Interim Report on the Use of 6mm Nominal Maximum Aggregate Size Polymer Modified Stone Mastic Asphalt (PMSMA6) on Local Roads in Hong Kong" issued by Highways Department (HyD) in June 2021, both overseas and local experiences revealed that Polymer Modified Friction Course (PMFC), attributed to its porous nature, is susceptible to wear and tear making it not sufficiently durable as LNRS materials for many situations to sustain the local road conditions. Therefore, PMFC is not taken as a structural layer and its application on local roads will require laying on top of wearing course ("WC") instead of base course ("BC").
2.1.2 A new type of LNRS materials, namely the polymer modified stone mastic asphalt of 6mm nominal maximum aggregate size (PMSMA6) which was tested in the study (Agreement No. Hy(S)Q/024/2016). It was found that PMSMA6 is a better mix than PMFC in various aspects, in particular for resisting rutting. Such findings tally with the understanding that the engineering performance of PMSMA6 (which is structural layer) is superior to PMFC (which is non-structural layer). Therefore, PMSMA6 can be laid on BC directly while PMFC has to be laid on top of WC in general in their application on bituminous road surface.
2.1.3 For the environmental benefits, the optimized texture of PMSMA6 which is smooth enough in minimizing tyre vibration and with small open texture to reduce air pumping, gives the surfacing certain noise reduction potential. Such noise reduction mechanism could be more sustainable than PMFC. PMSMA6 is considered a better LNRS materials alternative for local road conditions, as compared with PMFC.
2.1.4 It is recommended the use of the PMSMA6 as LNRS materials for this project. According to the approved EIA Report (Section 4.5.4) (relevant figures extracted in Appendix A) and Environmental Permit (EP) (EP No. EP-519/2016) (Figure 2) (extracted in Appendix B) for TCNTE and the agreement in the inter-departmental meeting as stated in Section 1.1.3, the extent and locations of LNRS materials for the roadworks are shown on Figure 1.1. The adoption of LNRS materials are approx. 210m long along Chung Mun Road, approx. 160m long along Road L29 and approx. 130m long along Road L30. There is no minimization of the extent of the noise barriers (refer to NB1 as shown in Appendix B) for the roadworks as resulting of applying the new road surfacing materials.
2.1.5 The lengths of road sections with Low Noise Road Surfacing (LNRS) materials along Chung Mun Road is approx. 210m long; Road L29 is approx. 160m long and Road L30 is approx. 130m long. The specific sensitive receivers where the traffic noise impacts will be reduced due to the provision of LNRS materials includes:
· Mun Tung Estate
· Hong Chi Shiu Pong Morninghope School
· YMCA of Hong Kong Christian College
· Caritas Charles Vath College
· Public Housing Development in Area 42
2.1.6 Apart from the LNRS materials along the road sections stated in Section 2.1.5, a section of 5m high vertical barrier with 3m cantilevered arm at 45° at the junction between Chung Mun Road and Road L29 (approx. 120m long) would be constructed. While the 4m high school boundary wall (approx. 50m long) at Mun Tung Estate will be constructed by others. The locations of the school boundary wall and the vertical barrier are shown in Appendix A.
Figure 1.1 – Adopted Extent of LNRS Materials
Appendix A – Figures on Mitigation Measures for Road Traffic Noise in Approved EIA
(Extracted from the EIA Report (AEIAR-196/2016) – Figure 4.14d and 4.14d-3)
Appendix B – Figure 2 of Environment
Permit No.: EP-519/2016
