11. SUMMARY OF ENVIRONMENTAL OUTCOMES

11.1 Overview

This chapter summarises the key environmental outcomes arising from the EIA Study. Chapter 2 outlines the analysis of alternative development options during the optioneering process, which has taken account of public views. Alternative options, designs and construction methodologies have been duly considered. The technical assessments (Chapter 3 to 9) conducted have demonstrated that all the statutory requirements in EIA Study Brief (EIA SB No.: ESB-310/2018) and Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) are complied with.

The following sections summarise the approaches that have been adopted to either avoid or minimise various environmental impacts throughout the design process, and the associated environmental enhancements and compensation measures.

11.2 Population and Environmental Sensitive Areas Protected

Air Quality Impact

In construction phase, fugitive dust may be generated from works activities including site clearance, excavation, handling of construction materials, concrete breaking and from minor wind erosion. Activities that may induce significant dust emissions such as extensive site formation and blasting are not required for Project development. The impact can be minimized with proper implementation of mitigation measures stated in Section 3.5.3. The population protected by the mitigation measures includes all air sensitive receivers (ASRs) within 500m from Project Boundary. The protected ASRs includes residents, place for worship, offices, parks and elderly centre along Kam Tin Road and Lam Kam Road.

In operation phase, cumulative air quality impact arising from the vehicular emissions from the open roads within the assessment area has been assessed at the worst-case-year. The assessment results conclude that the concerned air pollutant concentrations at representative ASRs would comply with the Air Quality Objectives.

Noise Impact

In construction phase, all representative NSRs identified within 300m from Project Boundary (total of 57 NSRs) can be protected with proper implementation of mitigation measures stated in Section 4.5.4. The protected NSRs includes residents, place for worship and elderly centre along Kam Tin Road and Lam Kam Road.

In operation phase, direct noise mitigation measures such as LNRS and vertical noise barrier are evaluated to minimize the operation noise impact. LNRS with total length of approximate 2.1km would be applied on several road sections of Kam Tin Road. A total length of approximate 837m vertical noise barriers with maximum height of 5.0m along Kam Tin Road and maximum height of 3.0m along Lam Kam Road are recommended for the NSRs with exceedance in unmitigated scenario. 106 out of 648 affected dwellings are protected and 565 out of 648 affected dwellings are benefited from the direct noise mitigation measures. The protected and/or benefited dwellings includes residents and planned residential areas, place for worship and elderly centre along Kam Tin Road and Lam Kam Road.

Water Quality Impact

Potential water quality impact might be arisen from the associated construction works of road widening and improvement works such as retaining wall and geotechnical works, which can be minimised with proper implementation of mitigation measures stated in Section 5.7. The environmental sensitive areas protected by the implementation of the mitigation measures include water gathering ground from the Project eastern end, local streams near Kadoorie Experimental Farm, Ling Wan Monastery, Wong Chuk Yuen, Sheung Tsuen and Kam Tin Bypass; nullah near Wang Toi Shan Hung Mo Tam, Shek Kong Barracks and the channelized Kam Tin River.

Ecological Impact

There will be disturbance from construction activities to nearby habitats and site runoff during construction phase which can be minimised with proper implementation of mitigation measures stated in Section 7.8. Nearby sensitive areas such as nearby waterbodies and habitats for wildlife are protected with proper implementation of mitigation measures.

Land Contamination

Site re-appraisal is required for the identified potentially contaminated sites as well as other areas within the Project Boundary to address any change in land use that may give rise to potential land contamination issues as soon as the sites become accessible and a supplementary CAP should be submitted and endorsed by EPD before site investigation. A CAR which includes the site investigation sampling and testing results will be prepared for EPD's agreement upon completion of the site investigation. If contamination is identified, RAP shall be also prepared and submitted to EPD for agreement prior to the commencement of the remediation works. Upon completion of the remediation, a RR shall be submitted to EPD for agreement. No construction works of site should be carried out prior to the agreement of the RR.

Landscape and Visual Impact

Based on the tree survey conducted, it is estimated that 756 trees will be felled, 1250 trees will be retained, and 43 trees will be transplanted. The design of the proposed engineering works has been carefully considered to retain as many of the existing trees as possible. The tree loss will be compensated through the planting and growth to maturity of not less than 756 heavy standard trees (with a DBH not less than 100mm) would be required for compensation in 1:1 ratio.

11.3 Summary of Environmental Designs Recommended, Environmentally Friendly Options Considered and Incorporated in the Preferred Option

Avoidance of environmental impacts has been one of the key considerations throughout the entire project development and design. For those impacts that could not be avoided, due consideration has been given to minimise those impacts as much as practicable.

A summary of these approaches is given below:

· Minimisation of impacts to Conservation Area;

· Preservation of habitats with ecological value;

· Avoidance of impacts to sensitive receivers along Kam Tin Road and Lam Kam Road;

· Avoidance of impacts to natural watercourses; and

· Provide compensation planting

Minimisation of impacts to Conservation Area

The preferred option reduced the encroachment of CA zones, resulting in only slight encroachment of the four CA zones at north of section between Chainage CHB 28+70 and CHB 30+10 of Kam Tin Road, south of section from CHB 44+30 to CHB 44+80 and CHB 49+00 to CHB 52+30 of Lam Kam Road as well as north of section between Chainage CHB 50+20 to CHB 52+40 of Lam Kam Road. However, the concerned CA zones are at the shotcreted slopes with common roadside tress, mixed woodland edge and slopes covered with herbaceous plants with a few common trees and shrubs, and hence the potential impact to habitat loss/vegetation clearance is considered to be minor. Detailed ecological impact assessment is in Section 7 of EIA study report.

Preservation of habitats with ecological value

To minimize habitat loss to the nearby habitats and associated wildlife, the following mitigation measures will be implemented:

· Confining the works within the Project Boundary;

· Controlling access of site staff to avoid damage to the vegetation in surrounding areas

· Placement of equipment or stockpile in the existing disturbed / urbanized area within the Project Boundary of the Project to minimize disturbance to vegetated areas

Avoidance of impacts to sensitive receivers along Kam Tin Road and Lam Kam Road

In order to minimise the impacts to sensitive receivers along Kam Tin Road and Lam Kam Road, environmental assessment on air quality, noise, water, waste, ecology, land contamination and visual and landscape has been conducted. Relative mitigation measures have been proposed in Chapter 3 to Chapter 9.

In addition, road works will be carried out section by section and each active construction work front will be limited to occupy about 50m x 10m work area at any one time, and with a separation distance of more than 600m between two concurrent work areas, to reduce concurrent environmental impacts to sensitive receivers.

Avoidance of impacts to natural watercourses

During the construction phase, site runoff would need to pass through sand/silt removal facilities to reduce the concentration of suspended solid. In accordance with the Practice Note for Professional Persons on Construction Site Drainage, Environmental Protection Department, 1994 (ProPECC PN 1/94), best management practices should be implemented on site as far as practicable to control site runoff and drainage at all work sites during construction phase, so that the treated runoff will be discharged to public drainage system in compliance with the WPCO. Construction effluent, site run-off and sewage should be properly collected and/or treated. Wastewater from a construction site should be managed. Proper locations for discharge outlets of wastewater treatment facilities well away from the natural watercourses should be identified. The best practices are detailed in the Water Quality Impact Assessment (Chapter 5). The following precautionary measures as referred in ETWB TC (W) No. 5/2005 to avoid any possible impacts on natural stream courses and/ or nearby vegetation during construction phase shall be implemented:

· Construction works close to the inland waters should be carried out in dry season as far as practicable where the flow in the surface channel or stream is low.

· The use of less or smaller construction plants may be specified in areas close to the water courses to reduce the disturbance to the surface water.

· Temporary storage of materials (e.g. equipment, chemicals and fuel) and temporary stockpile of construction materials should be located well away from any water courses during carrying out of the construction works.

· Stockpiling of construction materials and dusty materials should be covered and located away from any water courses.

· Construction debris and spoil should be covered up and/or disposed of as soon as possible to avoid being washed into the nearby water receivers.

· Proper shoring may need to be erected in order to prevent soil or mud from slipping into the watercourses.

· Fencing should be erected on the sides facing the nearest stream course to trap all wind-blown litters such as paper, plastic bags, bottles and boxes within the site from entering the nearby water bodies.

· The proposed works site inside or in the proximity of natural rivers and streams should be temporarily isolated, such as by placing of cofferdam with silt curtain with lead edge at bottom and properly supported props, to prevent adverse impacts on the stream water qualities. Other protective measures should also be taken to ensure that no pollution or siltation occurs to the water gathering grounds of the work site.

· The natural bottom and existing flow in the river should be preserved as much as possible to avoid disturbance to the river habitats. If temporary access track on riverbed is unavoidable, this should be kept to the minimum width and length. Temporary river crossings should be supported on stilts above the riverbed.

Provide compensation planting

Compensatory planting proposals have been recommended in the Landscape and Visual Impact Assessment (Chapter 9). The roadside of the upgraded roads has been proposed for tree compensation. The locations can be referred to Figure 9.11.

In addition, as discussed in Chapter 2, alternative options have been considered in terms of alignment, design alternative, construction method and construction sequence. It is proposed to implement several typical work fronts of maximum 50m in length at minimum 600m separation simultaneously along Kam Tin Road and Lam Kam Road to minimize the environmental impact to nearby sensitive receivers.

11.4 Key Environmental Problems Avoided

The key environmental problems involve ecological and noise impacts during the construction phase and operation phase. Minor impacts on air quality, waste, water quality, visual and landscape are expected.

The EIA study has critically assessed the overall acceptability of environmental impacts which are likely to arise as a result of the construction of the Project. Where necessary and practicable, the EIA study has specified the conditions and requirements for the detailed design and construction of the Project in order to mitigate environmental impacts to an acceptable level.

In order to avoid or minimize the environmental impacts of the Project, a number of mitigation measures have been recommended in the EIA report. The key environmental measures and problems avoided are highlighted below.

· With the implementation of quiet plant, temporary noise barriers and good site practices, construction noise from construction activities will be minimised;

· With the implementation of vertical noise barriers and low noise road surfaces, traffic noise in operation phase will be minimised;

· During construction phase, several typical work fronts of maximum 50m in length would be implemented at minimum 600m separation simultaneously along Kam Tin Road and Lam Kam Road to avoid cumulative impacts;

· Encroachment on Conservation Area (s) / Ecologically Sensitive Areas have been avoided and/or minimized as far as practicable and possible during the initial design stage;

· Mitigation measures such as confining the works within the Project Boundary, controlling access of site staff to avoid damage to the vegetation in surrounding areas and placement of equipment or stockpile in the existing disturbed / urbanized area within the Project Boundary of the Project to minimize disturbance to vegetated areas have been adopted to minimize habitat loss to the nearby habitats and associated wildlife.

A comprehensive EM&A programme will be setup to ensure effective implementation of mitigation measures recommended in the EIA report, to assess the effectiveness of the mitigation measures, and to identify any further need for additional measures or remedial actions.

11.5 Environmental Benefits of the Project

The development of the Project could result in the following local and strategic benefits:

l Increased noise protection due to direct noise mitigation measures such as noise barriers based on the findings from noise impact assessment. Existing traffic noise impact on the nearby sensitive receivers along Kam Tin Road and Lam Kam Road can be reduced as much as practicable

l Better visual impact in Operation Phase due to renewal of the existing road surface and associated auxiliary facilities along Kam Tin Road and Lam Kam Road, and aesthetic noise barrier

l New trees and plants will be planted along roadside

11.6 Environmental Benefits of Environmental Protection Measures Recommended

Mitigation measures have been recommended to further reduce the environmental impacts due to construction and operation of the Project. Key recommended mitigation measures and their associated benefits are summarised in Table 11.1 below.

Table 11.1 Key recommended mitigation measures and their associated benefits

Aspect	Key recommended mitigation measures and their associated benefits
Air Quality	· Limitation of each active construction work front to occupy about 50m x 10m work area at any one time, and with a separation distance of more than 600m between two concurrent work areas to reduce concurrent dust emission impacts; · Works area for site clearance shall be sprayed with water before, during and after the construction works so as to maintain the entire surface wet to reduce dust emission; · Hoarding of not less than 2.4 m above ground shall be provided, as far as practicable, along the Project Boundary which is next to the public areas to prevent dust emission leaving Project Boundary; · Any stockpile of dusty materials shall be covered entirely by impervious sheeting; and/ or placed in an area sheltered on the top and 4 sides to reduce dust emission; and · Immediately before leaving a construction site, all vehicles shall be washed to remove any dusty materials from its body and wheels to reduce dust emission
Noise	· Good site practices to limit noise emissions at the source; · Use of quality powered mechanical equipment (QPME); · Use of temporary noise barriers, enclosure and/or noise insulation fabric to screen noise from relatively static PMEs; · Alternative quiet construction method; and · Vertical noise barrier and Low Noise Road Surface to reduce noise level at NSR in operation phase
Water Quality	· Good site practices to minimize site runoff; · Surface runoff from construction sites should be discharged into storm drains via sand/silt removal facilities such as sedimentation basin/tank. Earth bunds or sand bag barriers with tarpaulin sheet should be provided on Project Boundary to intercept surface runoff from outside the site; · Silt removal facilities and manholes should be maintained and the deposited silt and grit should be removed regularly to maintain water quality at discharge; · Open stockpiles should be covered with a tarpaulin to avoid erosion during rainstorms to minimize site runoff; · Drainage traps such as grease traps and petrol interceptors will be installed at each of the drainage outlets to filter out chemical pollutants from surface runoff; · Contractor must register as a chemical waste producer if chemical wastes would be produced from the construction activities; · The practices outlined in ETWB TC (W) No. 5/2005 “Protection of natural streams/rivers from adverse impacts arising from construction works” would be adopted where applicable to prevent impact to natural streams/rivers; and · Road gullies would be provided to direct and collect all surface runoff to the drainage system to minimize site runoff. · The proposed works site inside or in the proximity of natural rivers and streams should be temporarily isolated, such as by placing of cofferdam with silt curtain with lead edge at bottom and properly supported props, to prevent adverse impacts on the stream water qualities. Other protective measures should also be taken to ensure that no pollution or siltation occurs to the water gathering grounds of the work site. · The natural bottom and existing flow in the river should be preserved as much as possible to avoid disturbance to the river habitats. If temporary access track on riverbed is unavoidable, this should be kept to the minimum width and length. Temporary river crossings should be supported on stilts above the riverbed.
Waste Management	· An on-site environmental co-ordinator should be identified at the outset of the works. The co-ordinator shall prepare an Environmental Management Plan (EMP) incorporating waste management in accordance with the requirements set out in the ETWB TC(W) No. 19/2005, Environmental Management on Construction Sites. The EMP shall include monthly and yearly Waste Flow Tables (WFT) that indicate the amounts of waste generated, recycled and disposed of (including final disposal site), and which should be regularly updated to ensure waste mitigation measures are properly implemented; · Good site practices shall be adopted from the commencement of works to avoid the generation of waste, reduce cross contamination of waste and to promote waste minimisation; and · Under the Waste Disposal (Chemical Waste) (General) Regulation, the Contractor shall register as a Chemical Waste Producer if chemical wastes such as spent lubricants and paints are generated on site. Only licensed chemical waste collectors shall be employed to collect any chemical waste generated at site. The handling, storage, transportation and disposal of chemical wastes shall be conducted in accordance with the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes and A Guide to the Chemical Waste Control Scheme both published by EPD
Ecology	· The Project Boundary is designed to avoid encroachment of the Lam Tsuen Country Park and the FSW; · A detailed vegetation survey will be conducted within the proposed works areas as well as the Conservation Area before construction to identify any plant species of conservation importance before construction activities to be carried out; · Confining the works within the Project Boundary to avoid disturbance; · Controlling access of site staff to avoid damage to the vegetation in surrounding areas; · Placement of equipment or stockpile in the existing disturbed / urbanized area within the site boundary of the Project to minimize disturbance to vegetated areas; · Reinstatement and enhancement of temporarily affected habitats; · Controlling of site runoff to prevent impact to natural streams/rivers; and · Reducing Glare / Lighting to minimize disturbance · To reduce collision from birds, the design of noise barrier will avoid / minimise the use of transparent / reflective materials or adopt bird-friendly design on the surfaces.
Land Contamination	· The Project Proponent shall engage a competent and experienced professional to prepare a supplementary CAP for EPD's approval when the sites become accessible; · A CAR which includes the site investigation sampling and testing results will be prepared for EPD's agreement upon completion of the site investigation; · If contamination was identified, RAP shall be also prepared and submitted to EPD for agreement prior to the commencement of the remediation works; · Upon completion of the remediation, a RR shall be submitted to EPD for agreement.
Landscape and Visual	· Preservation of existing vegetation to minimize landscape impact; · The landscape of these works areas should be restored to its original status or new amenity area following the completion of the construction phase to minimize landscape impact; · Replanting of disturbed vegetation should be undertaken at the earliest possible stage during the construction phase to minimize landscape impact; · The alignment and structures associated with the widened road should integrate, as far as technically feasible, with existing roadside structures and the landscape context to reduce the potential cumulative impact of the proposed works; · In accordance with DEVB TC(W) No. 7/2015, the compensatory planting proposal should have the basic primary objective of planting compensatory trees in a ratio not less than 1:1 in terms of quantity as far as practicable; · Treatment of retaining walls and slopes to minimize visual and landscape impact; and · Provision of visually pleasing aesthetic treatment on noise barriers.

11.7 Summary of Alternative Measures

Alternative options have been considered in terms of the following aspects:

• Alignment;

• Design alternative;

• Construction method; and

• Construction sequence

For alignment and design alternatives, the proposed work is aim to upgrading the existing sub-standard road to a standard road. The road sections of Kam Tin Road and Lam Kam Road to be upgraded are rural roads which are serving many existing road side developments, the proposed road alignment thus follows closely with the existing alignment. The proposed alignment is designed according to the principle of minimizing land resumption and environmental impacts. Constructing a new road and/or off-line realigning road will not be one of optimum and feasible option, especially constructing a new road, which would incur additional land resumption and bring undesirable impacts to the environment during and after implementation of these options. Thus, it is sensible not to adopt such alternative alignment and design for the road sections of Kam Tin Road and Lam Kam Road and no alternative option would be expected.

For construction methods and sequence of construction works alternatives, the existing Kam Tin Road and Lam Kam Road is the main road to Yuen Long, Fanling and Tai Po for the residents in Kam Tin. In order to minimize the traffic impact during implementation of Temporary Traffic Arrangement (TTA), the upgrading of at-grade road sections is a straight forward construction process that will not involve complicated construction sequences, the typical work fronts of maximum 50m in length would be implemented at minimum 600m separation simultaneously along Kam Tin Road and Lam Kam Road in stages, i.e. bound by bound. Conventional construction method of open-cut excavation should be adopted on the upgrading works of existing rural roads in Kam Tin area.

In view of the existing heavy traffic and potential traffic congestion during peak hours, under this construction method, although the construction period is longer, less complicated scheme of traffic diversion and less disturbance to the existing road side developments would be expected. In addition, the no. of tree to be affected and temporary land resumption for facilitating the temporary traffic diversion could be minimized under this construction method. In conclusion, the above proposed construction method and sequence of works would be the only one option that is the most cost effective and least adverse impact to the traffic and public.

In addition, the following measures have also been taken to minimise the environmental impacts.

Road section between Chainage CHB 43+90 and CHB 49+30 of Lam Kam Road

· Option A is to widen the carriageway northwards to minimize encroachment of two CA zones while Option B is to widen southwards. The sections forming the two alternative options are reviewed and made a detailed comparison, Option A is adopted as the preferred option. A brief summary of the assessment findings is described below:

i. The preferred option reduced the encroachment of CA zones, resulting in only slight encroachment of the two CA zones at south of section from CHB 44+30 to CHB 44+80 and CHB 49+00 to CHB 49+30 of Lam Kam Road. However, the concerned CA zones are at the woodland edge and partly shotcreted respectively, and hence the potential impact to habitat loss/vegetation clearance is considered to be low. Detailed ecological impact assessment is in Section 7 of EIA study report.

ii. Apart from less CA encroachment, another advantage of the preferred option is the need to resume relatively small area of private land.

Road section between Chainage CHB 48+00 and CHB 48+80 of South of Lam Kam Road

· The southern footway is proposed to be cut back in order to preserve the existing road side trees thereat.

Road section between Chainage CHB 49+10 and CHB 50+20 of Lam Kam Road

· The preferred option upgrades the carriageway and the footway, but the carriageway shall not follow the existing alignment and shift northwards. Such arrangement is to minimize the extent of CA encroachment at south of section between CHB 49+10 and CHB 50+20 of Lam Kam Road. Besides, considering that extensive geotechnical works will be required for providing the concerned southern footway, such arrangement can reduce waste, noise, air quality, landscape and visual impacts.

The sections of Kam Tin Road and Lam Kam Road to be upgraded are rural roads serving many road side residence and developments. Hence, the proposed road alignment follows closely with the existing alignment as far as practical. In addition, the proposed road alignment is designed based on the principle of minimising land resumption and environmental impacts. Two options have been proposed for the upgrading works. The layouts of Option A and Option B are attached in Figure 2.2 respectively. Summary of the comparison of Option A and Option B based on their environmental benefits and dis-benefits can be referred to Table 2.2.

Among the two options proposed, Option A is selected as it will cause less impact on local community, and involve in smaller scale construction works, which leads to smaller environmental impact during construction phase. Although Option A will slightly encroach on CA, the concerned area is a paved footway with isolated trees, and hence the potential impact to habitat loss/vegetation clearance is considered to be low.