1                                  Introduction

1.1                            Background

At present, traffic queues are already observed on the northern approach of Pok Oi Roundabout (POR) during the evening peak period, and the southern approach during both morning and evening peak hours.  The situation will likely deteriorate further when nearby developments are completed.  The tailback of traffic onto the southbound carriageway on the northern approach to POR may block the through traffic from Tai Lam Tunnel / New Territories (NT) North to Tuen Mun / Tin Shui Wai / Hong Kong – Shenzhen Western Corridor.  A traffic improvement scheme is considered necessary to relieve the traffic congestion. 

ERM-Hong Kong, Ltd (ERM), supported by Halcrow China Ltd (Halcrow), has been commissioned by the Highways Department (HyD) to undertake the Improvement to Pok Oi Interchange – Environmental Impact Assessment Study (“the Assignment”) under Agreement No. WD 6/2007.  As part of the Assignment, an Environmental Impact Assessment (EIA) Study has been prepared in accordance with the EIA Study Brief (No. ESB-166/2007) issued under the Environmental Impact Assessment Ordinance (EIAO).  

The EIA Report addresses potential environmental impacts associated with the construction and operation of the Improvement to Pok Oi Interchange (“the Project”).  This Executive Summary summarises the key findings of the EIA.

1.2                            Objectives of and Approach to the EIA Study

The objectives of the EIA Study are to provide information on the nature and extent of environmental impacts arising from the Project; to recommend appropriate mitigation measures to control the potential environmental impacts so that it complies with the requirements of the Technical Memorandum on Environmental Impact Assessment Process of the EIAO (EIAO-TM); and to confirm the environmental acceptability of the Project.  Key environmental issues identified in the EIA Study Brief include air quality, noise, water quality, waste management, and landscape and visual impacts.

The EIA was conducted in accordance with the guidelines on assessment methodologies provided in the EIAO-TM.  The general approach for the assessment includes description of baseline environmental conditions for the impact assessment, identification and evaluation of potential impacts and recommendation of mitigation measures and an environmental monitoring and audit programme.  The assessments in this EIA Study are conducted using well-proven and internationally accepted methods based on reasonable worst-case conditions. 

Alternative construction methods and sequences of works have been considered and environmentally friendly construction methods have been adopted to avoid / minimise impacts to the surrounding sensitive receivers, where appropriate and practicable.

 

2                                  Project DESCRIPTION

2.1                            Scope of the Project

The proposed alignment of the Project is shown in Figure 2.1a.  The scope of the Project is as follows:

·           provision of a single lane flyover (approximately 140m in length) adjacent to the northbound carriageway of Pok Oi Flyover (POF) (denoted as Flyover A in Figure 2.1a and subsequent sections of this report);

·           construction of a slip road (approximately 410m in length) connecting the northbound carriageway of the ground level road of Yuen Long Highway (YLH) on the southern arm of POR to the proposed flyover (denoted as Slip Road A in Figure 2.1a and subsequent sections of this report);

·           construction of a slip road (approximately 100m in length) connecting the proposed flyover to the northbound carriageway of the ground level section of YLH on the northern arm of POR (denoted as Slip Road B in Figure 2.1a and subsequent sections of this report);

·           construction of a slip road (approximately 280m in length) connecting the southbound carriageway of POF to the southbound carriageway of the ground level section of YLH on the southern arm of POR (denoted as Slip Road C in Figure 2.1a and subsequent sections of this report);

·           resurfacing and re-marking of a stretch of the southbound carriageway (approximately 280m in length) of the ground level section of YLH on the northern arm of POR to increase the number of traffic lanes on the carriageway from three to four (denoted as Road Resurfacing and Remarking A in Figure 2.1a and subsequent sections of this report);

·           resurfacing and re-marking of a stretch of the northbound carriageway (approximately 470m in length) of the ground level section of YLH on the northern arm of POR (denoted as Road Resurfacing and Remarking B in Figure 2.1a and subsequent sections of this report);

·           construction of a segregated left-turn lane (approximately 110m in length) at the northern arm of POR (denoted as Left-turn Lane A in Figure 2.1a and subsequent sections of this report); and

·           associated ancillary works.

2.2                            Work Programme

The construction of the Project is scheduled to commence in December 2009 and to be completed in December 2011. 

 

3                                  Environmental Impacts

The potential environmental impacts associated with the Project are summarised in the following sections.

3.1                            Air Quality

Potential dust nuisance from construction activities and gaseous emissions from diesel-powered construction plant have been considered.  With the implementation of the recommended dust control measures and adoption of good construction site practices, adverse dust and air quality impacts from the construction of the Project are not anticipated.

Upon completion of the Project, vehicular emissions from the open roads would be the potential source of air quality impact.  The key air pollutants from vehicular emissions include Nitrogen Dioxide (NO2) and Respirable Suspended Particulates (RSP).  A quantitative assessment has been conducted using the peak hourly traffic flow of the proposed new roads and the surrounding road network and fleet emission factors estimated using the EMFAC-HK model.  The prediction indicated no exceedance of hourly and daily average concentrations of NO2 or daily average concentrations of RSP in the vicinity of the Project.

It must be emphasised that the objective of the Project is only to relieve the traffic pressure and traffic queues of the existing POR and the design traffic flow / capacity ratio will be maintained.  There will not be any increase in the overall traffic flow as a result of this Project. 

The vehicular emissions associated with road traffic with the implementation of the Project are expected to comply with the respective AQOs, and therefore will not cause an adverse air quality impact.

Regular site audits are recommended to ensure the implementation of recommended dust control measures and adoption of good site practices during construction.

3.2                            Noise

Potential construction noise impacts will mainly be due to road works, construction of flyover, construction of retaining walls, abutments and embankments.  During normal daytime working hours, the predicted noise levels at some of the representative noise sensitive receivers (NSRs), including the Jockey Club Care & Attention Home, Kwong Ming Ying Loi School and the village houses near YLH will exceed the construction noise criteria stipulated in the EIAO-TM.  With the implementation of noise mitigation measures such as the use of quiet powered mechanical equipment, movable noise barriers and scheduling of PMEs/construction activities, the noise levels at the NSRs would comply with the EIAO-TM construction noise criteria.

The potential road traffic noise impacts have been assessed based on the Year 2026 traffic forecast, which is the maximum projected traffic level.  With the provision of a 2.5 m high vertical noise barrier for the planned school, no adverse noise impacts are predicted at the NSRs during the operational phase of the Project.  In the design year for the Project, the traffic noise levels for the case with the Project in operation will not be significantly higher, ie by 1.0 dB(A) or more, than those for the case without the Project.  Based on the above, the traffic noise impact due to the Project is considered insignificant.  Furthermore, the mitigated noise levels due to the road sections within the meaning of Item A.1 of Schedule 2 under the EIAO complied with the noise criteria as stipulated in the EIAO-TM.

Monitoring of construction noise and road traffic noise is recommended to verify the effectiveness of the mitigation scheme during the construction period and during the first year after the commencement of operation.

3.3                            Water Quality

Potential sources of water quality impact associated with the Project include Site runoff, discharges from construction activities and sewage effluents from the on-site workforce.  Water quality impacts from the land-based construction works can be controlled to acceptable levels by implementing the recommended mitigation measures.  All the effluents and runoff generated from the Site will be treated to relevant standards stipulated in the Technical Memorandum - Standards For Effluents Discharged Into Drainage And Sewerage Systems, Inland And Coastal Waters issued under Water Pollution Control Ordinance (WPCO-TM) before discharge.  No unacceptable water quality impact is expected from the land-based construction activities with the adoption of appropriate drainage management and mitigation measures.  Regular site inspections are recommended to ensure that the recommended mitigation measures are properly implemented.

For the operational phase, a road drainage system with appropriate silt or grit traps will be provided to collect runoff from the road surface during periods of rain.  With the provision of an appropriate road drainage system, no adverse water quality impacts are anticipated.  No operational water quality monitoring is considered necessary.

3.4                            Waste Management

Wastes generated by the construction activities are likely to include construction and demolition (C&D) materials from the construction works, general refuse from the workforce and chemical waste from any maintenance of construction plant and equipment.  Provided that these identified waste arisings are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts are not anticipated during the construction works.

The potential land contamination impacts within the Study Area have been examined.  Based on the findings from the desktop studies and site inspection, no contaminated sites were identified within the vicinity of the Project boundary. 

3.5                            Landscape and Visual Impact

Three Landscape Character Areas (LCAs), LCA1 Miscellaneous Rural Fringe Landscape, LCA2 Miscellaneous Urban Fringe Landscape, and LCA3 Urban Peripheral Village Landscapes, were identified.  The residual impacts on all three LCAs will be negligible.

A total of seven Landscape Resources (LRs), LR1 Roads, LR2 Agricultural Land, LR3 Roadside Plantation, LR4 Developed Area, LR5 Disturbed Area, LR6 Nullah and LR7 Village, were identified.  LR3 Roadside Plantation will experience moderate adverse and slight adverse residual impacts during construction and operation respectively.  However, there will be negligible residual impacts on all other Landscape Resources.

Four Visually Sensitive Receivers (VSRs) , VSR1 Sun Yuen Long Centre, VSR2 Pok Oi Hospital, VSR3 Kwong Ming Ying Loi School and VSR4 Yeung Uk Tsuen, were identified.  There will be negligible residual impacts (impact at year 10) on all four VSRs.

According to Annex 10 of the EIAO-TM, the landscape and visual impacts are considered acceptable with mitigation.

3.6                            Environmental Monitoring and Audit

Environmental monitoring and audit (EM&A) requirements have been identified and recommended to ensure the effectiveness of the recommended mitigation measures.  These requirements are outlined in the EIA Report.  Monitoring of construction noise and operational road traffic noise is recommended to check compliance with relevant statutory criteria and to ensure the effectiveness of the mitigation measures.  Site inspection and audit are also recommended to ensure that the recommended mitigation measures are in place and operating effectively during construction. 

 

4                                  Overall Conclusion

The environmental impact assessment has concluded that the construction and operation of the Project will not cause any unacceptable environmental impacts, provided that the recommended mitigation measures are implemented. 

To ensure the effectiveness and proper implementation of the recommended mitigation measures, an EM&A programme has also been recommended.