(i) To describe the Project and associated works together with the requirements and environmental benefits for carrying out the Project and the types of designated projects to be covered by the Project;

(ii) To identify and describe elements of community and environment likely to be affected by the Project and/or likely to cause adverse impact to the Project, including natural and man-made environment and the associated environmental constraints;

(iii) To provide information on the consideration of alternatives design options of the Project including scale, extent, layout, configuration, design and type of design orientation and the construction methods with a view to avoiding and minimizing potential environmental impacts to environmentally sensitive areas and sensitive uses; to compare the environmental benefits and dis-benefits of different options; to provide reasons for selecting the preferred option(s) and to describe the part environmental factors played in the selection of preferred option(s);

(iv) To identify and quantify emission sources (including air quality, noise, water quality and waste, etc. as appropriate) and determine the significance of impact on sensitive receivers and potential affected uses;

(v) To identify and quantify any potential losses or damage and other potential impacts to ecology, flora, fauna and natural habitats and to propose measures to mitigate these impacts;

(vi) To identify any potential landscape and visual impacts and to propose measures to mitigate this impact;

(vii) To propose provision of infrastructure or mitigation measures so as to minimize pollution, environmental disturbance and nuisance during construction and operation of the Project;

(viii) To investigate the feasibility, practicability, effectiveness and implications of the proposed mitigation measures;

(ix) To identify, predict and evaluate the residual environmental impact (i.e. after practicable mitigation) and the cumulative effects expected to arise during construction and operation phases of the Project in relation to the sensitive receivers and potential affected uses;

(x) To identify, assess and specify methods, measures and standards, to be included in the detailed design, construction and operation of the Project which are necessary to mitigate these environmental impacts and cumulative effects and reduce them to acceptable levels;

(xi) To investigate the extent of the secondary environmental impact that may arise from the proposed mitigation measures and to identify constraints associated with the mitigation measures recommended in the EIA study, as well as the provision of any necessary modification; and

(xii) To design and specify environmental monitoring and audit requirements to ensure the effective implementation of the recommended environmental protection and pollution control measures.

1.3 Structure of the EIA Report

1.3.1 The EIA report presents the environmental impact that may arise from the Project and the associated mitigation measures, as follows:-

l Chapter 1 (Introduction) – Introduces the background information and the layout of the EIA Report;

l Chapter 2 (General) – Project Description;

l Chapter 3 (Air Quality Impact) – Presents the legislation, methodology, assessment and recommendations for air quality impact;

l Chapter 4 (Noise Impact) – Presents the legislation, methodology, assessment and recommendations for noise impact;

l Chapter 5 (Water Quality Impact) – Presents the legislation, methodology, assessment and recommendations for water quality impact;

l Chapter 6 (Waste Management) –Presents the legislation, methodology, assessment and recommendations for waste management;

l Chapter 7 (Ecological Impact) – Presents the legislation, methodology, assessment and recommendations for ecological impact;

l Chapter 8 (Landscape and Visual Impact) – Presents the legislation, methodology, assessment and recommendations for landscape and visual impact;

l Chapter 9 (EM&A Requirements) – Presents the EM&A requirements; and

l Chapter 10 (Conclusion) – Summarizes the findings.

2. Project DescriptionS

2.1 Need of the Project

2.1.1 Silver Mine Bay is a popular bathing beach in Mui Wo, Lantau. According to the EPD’s “Beach Water Quality in Hong Kong 2012”, the beach attracted 4,550 visitors on a peak day and over 69,000 visitors utilized the beach in 2012. The shortest route from the pier to this beach is by crossing the Wang Tong Bridge (hereafter called “Old Bridge”).

2.1.2 During holidays, people enjoy cycling around Mui Wo for sightseeing. As the bridge is only about 1.5m wide, overcrowding problem occurs and pedestrians and cyclists are often crossing the bridge shoulder to shoulder. According to Civil Engineering Development Department (CEDD)’s “Improvement Works for Mui Wo Facelift – Feasibility Study” in 2007, the hourly peak flow of the Old Bridge was 650 pedestrians and 250 bikes. This also raises concern on the risk of accident caused by pedestrians being hit by bicycles.

2.1.3 Possibility of extending the existing bridge was explored in Technical Feasibility Study (TFS) for New Wang Tong River Bridge prepared in 2011. However, the Old Bridge was not constructed up to the current design standards. After its service for over 40 years, its condition is in general poor. Mere widening and upgrading of the Old Bridge are therefore not cost effective or technically practical. Therefore, the TFS proposed to replace the Old Bridge by a new bridge comprising 4m wide cycle track (inclusive of 0.5m verge), 2m footpath and 0.35m wide utility trough.

2.1.4 The purpose, objectives and benefits of project are as follows:

l Demolish the Old Bridge and construct a wider New Bridge (including deck, abutments and retaining walls) with segregation for pedestrians and cyclists to relieve overcrowding problem and road safety concern

l CEDD planned to improve the existing segregated cycle track and footpath on the southern side of the Old Bridge and provide cycle parking area on the northern side of the Old Bridge. The New Bridge design is also suggested to align with the future development on both sides of the bridge for continuity.

l Carry out associated works including drainage works (e.g. u channel & catch pit), traffic aids (e.g. road paint) and street lighting modification (e.g. lighting column & lighting meter cabinet), environmental mitigation measures and landscaping works.

l The ground level of the Old Bridge is about 3.5 mPD. The water level of the Wang Tong River under heavy rain and high tide is about 2.36 mPD. This raises safety concern to the pedestrians of the Old Bridge in case of extreme weather. Therefore, the deck level of New Bridge shall be raised.

2.1.5 Without the proposed New Bridge, the congestion problem and safety concern at the Old Bridge will remain unresolved, not to mention the increase in future traffic demand due to streetscape enhancement and the improvement works at Mui Wo and the promenade along the Silver Mine Bay Beach. The level of Old Bridge is equal to the maximum water level under 1 in 50 years event (+3.5mPD), posing danger to bridge users under heavy storm. Therefore, it is favourable to replace the Old Bridge to alleviate these concerns.

2.2 Consideration of Alternative Design and Layout

Alternative Alignment

2.2.1 As mentioned in Section 2.1.3 above, improving the existing bridge is not cost effective or technically practical due to its poor condition. Keeping the Old Bridge is also not preferred due to substandard design to cater for adverse drainage situation (see Section 2.1.5). Therefore, the Old Bridge shall be replaced by a new bridge.

2.2.2 In total, three New Bridge options were proposed:

l Alignment Option 1 – One Single Bridge with Intermediate Bridge Support below high water mark (Design in the TFS and used in Project Profile PP-478/2013) (Figure 2.1)

l Alignment Option 2 – One Single Bridge with no Intermediate Bridge Support (Figure 2.2)

l Alignment Option 3 – Two Separated Bridges with Intermediate Supports above high water mark (Preferred design in this EIA) (Figure 1.2)

2.2.3 Option 1 is a design proposed in TFS, Project Profile and Study Brief. It consists of a single 6.35m wide bridge with approach footway and cycle track to replace the Old Bridge. The new bridge will be supported by one intermediate support below high water mark in Wang Tong River. This scheme satisfies the functional and layout requirements; however, some of the drawbacks are explained below:

l The structure is bulky and visually unattractive;

l Heavy foundation requires the use of large scale piling rigs, occupying more amenity area of the beach, requiring longer approach ramps at the north side and clashing more existing trees;

l The levels of the footpath and cycle track on both approaches are higher than the existing formation level with steep ramps and sharp bends. Substantial site formation works involving modification and strengthening of the existing seawalls and retaining walls are required.

2.2.4 In summary, this design has low structural efficiency with adverse implications on constructability, geotechnical, drainage and environmental impacts and cost. Furthermore, there is room for improvement in the functional and layout arrangement and landscape and visual impacts.

2.2.5 In Option 2, a single bridge with no intermediate support was proposed to replace the Old Bridge. The advantages of this Option will be reducing environmental and drainage impacts by removing the need for channel dredging, reducing deck thickness, and increasing the freeboard below. However, this Option will require an increased deck span with implications for bridge structural form, support and foundations. The disadvantage of these will be result in a much larger visual profile than a concrete beam construction.

2.2.6 In Option 3, two separated bridges with intermediate support outside the river was proposed to replace the Old Bridge. The advantages of this Option include,

l providing complete separation of cycle track and footpath,

l providing an efficient and safe transition such that building lots abut on the footpath instead of bicycle rack and the cycle track,

l minimizing privacy and security concerns to Silver Mine Bay on the south side by designing the deck level below which bridge user can overlook the interior of hotel,

l providing slimmer New Bridge that reduces the extent of ramp modification and strengthening at both ends and provides adequate freeboard to Wang Tong River,

l avoiding substantial surcharge to existing seawalls and retaining walls,

l minimising construction and demolition works below high water mark (HWM) within Wang Tong River,

l improving drainage performance by eliminating pier of the Old Bridge and raising the soffit of the bridge further above water

l reducing the length of approach ramp which would be received better by the public.

2.2.7 A comparison table on the potential environmental impacts between the three options is shown below:

Table 2.1: Comparison of Bridge Designs

Considerations	Option 1	Option 2	Option 3
No. of Pier	1	0	1
Location of Pier	Center of River	N/A	Above high water mark
Dredging *	Yes	No	Yes, but less than Option 1
Blockage of River Flow	Permanent partial blockage by new pier	No central pier, no additional permanent blockage of river flow	New Pier above high water mark, no additional permanent blockage of river flow
Felling of Trees	More	Fewer	Fewer
Impact on Naturalness	- Minor loss in sandy shore - Minor permanent loss in river bed by new pier	- Minor loss in sandy shore - No additional loss of river bed	- Minor loss in sandy shore - No additional loss of river bed
Landscape and Visual Impact	Bulkier than Old Bridge	Bulkier than Old Bridge	Each new bridge is of similar bulkiness as Old Bridge
Note: * Exclude removal of Old Bridge pier - Better options are bolded

2.2.8 Table 2.1 shows that Option 1 is expected to bring the greatest impact out of the three options. Both Option 2 and 3 will not cause additional permanent blockage of Wang Tong River and river bed and fewer impact on trees. Although Option 2 does not involve dredging works for construction of new pier, the overall design is much bulkier than Option 3 (i.e. 1.4 m deck thickness in Option 2 comparing to 0.9 & 1.2 m deck thicknesses in Option 3) so that the bridge can sustain its structure without pier support. Adverse opposition from locals is expected due to significant visual impact. The pier of Option 3 is located above high water mark and thus only minor dredging works will be involved. Given Option 3 is more favourable than the other two, the New Bridge design with two separated bridges is therefore selected as being suitable to take forward.

2.3 Consideration of Alternative Construction Methods and Sequences of Works

2.3.1 Construction of New Bridge and demolition of Old Bridge involves the following major activities:

· Demolition works

· Piling

· Dredging/Excavation and backfilling

· Bridge building (formation of bridge structure and concreting)

Alternative Construction Methods

Consideration of “No-dredge Option”

2.3.2 Possibility of cutting the central pier of the Old Bridge down to the riverbed surface only has been explored. However, Drainage Services Department requested further cutting for better drainage performance. Therefore, removal of Old Bridge pier down to 300mm below riverbed requiring dredging works was proposed. This design received no further departmental comment.

Demolition of Central Pier of Old Bridge

2.3.3 Cutting and breaking are typical demolition methods. Alternative demolition method of the central pier of Old Bridge within the HWM is by application of strong acid solution, e.g. nitric acid, to dissolve the mild steel bars under seabed level. However, this raises concern on the potential leakage of strong acid into Wang Tong River, causing undesirable water quality impact on this ecologically sensitive habitat and the bathing beach downstream. Therefore, demolition of pier by cutting is adopted.

Piling

2.3.4 Bored piling is a common method in bridge pier construction. However, given the limited space at the river bank and popular usage of the gazetted beach, use of large bored piling machine is not preferred. Also, bored piling involves extensive excavation work before placement of large diameter bored piles. Much dredged/excavated materials and wastewater will be generated.

2.3.5 A more environmentally friendly method minipiling is proposed. Minipiling machine is much smaller and thus less space demanding. It will be easier to be delivered to the Site as well. Only small scale excavation work will be needed for driving minipiles into soil, thus generating less excavated materials and wastewater.

Excavation Area of Abutment/Pier of New Bridge

2.3.6 In order to construct minipiles for the new bridges, fully enclosed cofferdam constructed from sheet piles will be installed around the pier with 1m clearance from pile cap. Excavation/dredging will be conducted within cofferdam. The works area of the southern abutment and central pier of the new bridges may fall within the HWM.

2.3.7 For new cycle bridge, the works area of the southern abutment and central pier of the will be within the HWM by 0.22 m² and 1.10 m² respectively.

2.3.8 For new pedestrian bridge, the existing abutments and pile caps will be demolished before construction of the new bridges at the same location. The works area of the southern abutment and central pier of the new cycle bridge will be within the HWM by 3.30 m² and 3.64 m² respectively.

2.3.9 While construction at the HWM is required, the water level may not always reach the work site depending on the tidal phase. Therefore, the excavation/dredging at the abutment within HWM during the construction period may be conducted in dry condition.

Bridge Construction

2.3.10 Sections of structural steel (7m x 1m) shall be delivered to the Site. The steel sections will be prefabricated in the northern part of works area. The bridge section will then be moved to the proposed bridge location for erection and concreting. This can minimize the activity above water and the chance of dropping debris into water.

Sequences of Works

2.3.11 To minimize the number of concurrent activities, construction and demolition works will be carried out in sequence:

(1) Construction of new cycle bridge

(2) Demolition of Old Bridge

(3) Construction of new pedestrian bridge

2.3.12 Although the duration of work will be prolonged, slow work process requires fewer plant equipment and thus produce less noise nuisance.

2.4 Selection of Preferred Scenario

Preferred Design and Layout

2.4.1 The preferred bridge layout is a twin bridges design having one supporting pier above high water mark (Option 3). This design is beneficial in terms of pedestrian/cyclist safety as well as overall smaller environmental impact:

· no permanent damage on riverbed or obstruction of river flow;

· fewer impact on trees during construction;

· smaller landscape and visual impact by having low profile and design that matches with surrounding rural environment.

2.4.2 The deck of the New Bridge is designed at about 5.40mPD highest with 0.3m freeboard, which is capable of passing 1 in 100 year flooding.

Preferred Construction Methods

2.4.3 Minipiling will be adopted for constructing foundation of the New Bridge, which requires smaller space for accommodating the piling machine and this method also generates fewer excavated materials than traditional bored piling.

2.4.4 Dredging/Excavating below high water mark cannot be avoided at the pier of Old Bridge in order to improve drainage performance of Wang Tong River. However, fully enclosed cofferdam will be installed around the piling and pier demolition works area to prevent dispersion of dredged/excavated materials into water.

2.4.5 Existing pile cap at southern abutment of pedestrian bridge is proposed to be demolished.

Detailed Construction Methods

2.4.6 The construction method of the Project can be divided into 3 major parts: 1.) construction of the new cycle bridge, 2.) demolition of old bridge, and 3.) construction of new pedestrian bridge.

Construction of New Bridge (Both cycle and pedestrian bridges)

2.4.7 Procedures for constructing the New Bridge would be as follow:

(1) Install mini-piles by boring machine with steel casing at abutments and column support above High Water Mark (HWM);

(2) Perform loading test for mini-piles;

(3) Install shoring work for excavation of pile cap;

(4) Construct pile cap, abutments and column;

(5) Remove temporary shoring works and backfilling;

(6) Erect structural steel truss / girder between column and abutment as temporary works for bridge construction;

(7) Erect steel beams and cast concrete deck; and

(8) Complete all finishes and street furniture.

Demolition of Old Bridge

2.4.8 Procedures for demolishing the Old Bridge would be as follow:

(1) Demolish spine beam by hand held tools;

(2) Install cofferdam around old pier (1m clearance from old pier, i.e. about 2.4 x 2.8m²);

(3) Adjust working platform and demolish RC (reinforced concrete) column down to 300mm above river bed level by either hand held tools or saw cutting;

(4) Further cut the concrete down to 300mm below river bed level by hand held percussive pneumatic tools, cut the reinforcement and mild steel bars down to 300mm below river bed level by pneumatic saw;

(5) Fill the hole in the river bed with the demolished concrete;

(6) Remove cofferdam around old pier;

(7) Install cofferdam around existing abutments;

(8) Demolish the top level of existing abutments down to about 3.2mPD;

(9) Trim the existing abutments to act as seawall

(10) Remove cofferdam around abutment.

2.5 Designated Project

2.5.1 The Project consists of the following designated projects under Part I, Schedule 2 of the Environmental Impact Assessment Ordinance (EIAO):

· Item C.12 – (a)…a dredging operation which is less than 500m from the nearest boundary of an existing…(iii) bathing beach…

2.5.2 Silver Mine Bay Beach is a gazetted bathing beach and just located next to the Project site. According to the construction method, the piers/abutments for the new bridges will be constructed within high water mark. Excavation area below high water mark (i.e. dredging operation) will be needed for the construction of these piers/abutments. The excavation area is hatched in cyan in Figure 2.3 and intended quantity is approximately 323m³.

2.6 EIA Study Brief

2.6.1 A project profile (PP-478/2013) has been submitted by Highways Department to Environmental Protection Department on 28 January 2013 and a study brief (ESB- 256/2013) has been issued to HyD in March 2013.

2.7 Construction Programme

2.7.1 As access across Wang Tong River has to be maintained during construction period, the new cycle bridge will be constructed first before demolition of the Old Bridge and subsequent construction of new pedestrian bridge.

2.7.2 The construction work is expected to last for two years from mid-2017 to mid-2019. The proposed breakdown of programme can be found in Appendix 2A.

2.8 Concurrent Projects

2.8.1 Currently, there are one planned and one ongoing projects within the Study Area.

(1) Signature Project Scheme (Islands District) – Improvement Works at Silvermine Bay Beach, Mui Wo, Lantau Island by the Home Affairs Department (HAD); and

(2) Upgrading of Mui Wo Sewage Treatment Works and Village Sewerage at Wang Tong and Yue Kwong Chuen managed by the Drainage Services Department (DSD).

2.8.2 The latest status and activities that are predicted to overlap with the work programme of this Project have been sought from respective project engineers/architects. Details are attached in Appendix 2B.

2.8.3 The scope of HAD project is as follows:

(a) demolition of the existing beach service buildings;

(b) construction of new beach buildings and associated beach facilities with an approximate construction floor area of 938 m²;

(d) construction of a viewing deck near the entrance to the beach.

2.8.4 The anticipated construction period is January 2016 – January 2017, which will not overlap with this Project (to be commenced in second half of 2017).

2.8.5 The scope of DSD project is as follows:

(a) upgrading of existing Mui Wo Sewage Treatment Works

(b) upgrading of truck sewers along Ngan Kwong Wan Road from 450mm dia. to 750mm

2.8.6 Only Scope (c) is located in the vicinity of Wang Tong River Bridge. Sewer laying and manholes construction works were substantially completed and reinstatement works is in progress. The outstanding activities are as follows:

(i) Reinstatement of the roadside covered U-channel, cycle track and footpath pavements (to be completed by end of December 2015);

(ii) The pipe cleaning and CCTV;

(iii) Painting of manhole internal wall face with epoxy paint (will be carried out in mid-2017).

2.8.7 Activity (ii) and (iii) of the DSD project may overlap with this Project in mid-2017. Nevertheless, these are minor works that do not involve use of powered plant equipment or dusty works. No cumulative impact is expected.

2.8.8 In conclusion, no project that involves heavy construction or dust emitting activity is known to be carried out concurrently with the construction work of this Project.

3. Air Quality Impact

3.1 Introduction

3.1.1 This Chapter assesses potential air quality impact arising from both construction and operation of the Project. Where necessary, mitigation measures have been proposed and their effectiveness has been evaluated.

3.2 Environmental Legislation, Standards and Guidelines

3.2.1 The Air Pollution Control Ordinance (Cap. 311) provides for the control of air pollutants from a variety of stationary and mobile sources through the establishment of a set of Air Quality Objectives (AQOs). Since 1^st January 2014, a new set of air quality objectives which stipulates maximum concentrations for a range of pollutants, i.e. nitrogen dioxide (NO₂), sulphur dioxide (SO₂), respirable suspended particulates (RSP), fine suspended particulates, carbon monoxide (CO), photochemical oxidants (O₃) and lead (Pb), has been in force. Details of AQOs are listed in Table 3.1.

Table 3.1: Hong Kong Air Quality Objectives

Pollutant	Averaging time	Concentration limit [i] (μg/m³)	Number of exceedances allowed
Sulphur dioxide	10-minute	500	3
Sulphur dioxide	24-hour	125	3
Respirable suspended particulates (PM₁₀) [ii]	24-hour	100	9
Respirable suspended particulates (PM₁₀) [ii]	Annual	50	Not applicable
Fine suspended particulates (PM_2.5) [iii]	24-hour	75	9
Fine suspended particulates (PM_2.5) [iii]	Annual	35	Not applicable
Nitrogen dioxide	1-hour	200	18
Nitrogen dioxide	Annual	40	Not applicable
Ozone	8-hour	160	9
Carbon monoxide	1-hour	30,000	0
Carbon monoxide	8-hour	10,000	0
Lead	Annual	0.5	Not applicable

Note:

[i] All measurements of the concentration of gaseous air pollutants, i.e. sulphur dioxide, nitrogen dioxide, ozone and carbon monoxide, are to be adjusted to a reference temperature of 293 Kelvin and a reference pressure of 101.325 kilopascal.

[ii] Respirable suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 10 μm or less.

[iii] Fine suspended particulates means suspended particles in air with a nominal aerodynamic diameter of 2.5 μm or less.

3.2.2 Criteria and guidelines in Annex 4 and Annex 12 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) will be followed for evaluating air quality impacts. Annex 4 stipulates criteria for evaluating air quality impacts. This includes compliance of the Air Quality Objectives (AQOs) and other standards established under the Air Pollution Control Ordinance, as well as meeting the hourly Total Suspended Particulate concentration of 500 µg/m³ and the 5-second average odour concentration of 5 odour units (ou). Annex 12 provides guidelines for conducting air quality assessments under the EIA process, including determination of air sensitive receivers, assessment methodology and impact prediction and assessment.

3.2.3 For construction dust, Annex 4 of EIAO-TM specifies a TSP limit concentration averaged over a 1-hour period to be 500 µg/m³. Mitigation measures for construction sites have been specified in the Air Pollution Control (Construction Dust) Regulation. It also requires Contractors and site agents to inform EPD and adopt dust reduction measures while carrying out “Notifiable Works” or “Regulatory Works” as defined under the regulation. Works relevant to this Project include both “Notifiable Works” (road construction) and “Regulatory Works” (dusty materials handling, excavation).

3.2.4 The Air Pollution Control (Non-road Mobile Machinery) (Emission) Regulation covers non-road mobile machinery (NRMMs) include a wide range of mobile machines (including transportable industrial equipment), or vehicles powered by internal combustion engines used primarily off-road. All regulated machines sold or leased for use in Hong Kong, except those exempted, are required to comply with the prescribed emission standards. Starting from 1 December 2015, only approved or exempted NRMMs with a proper label are allowed to be used in specified activities and locations including construction sites, container terminals and back up facilities, restricted areas of the airport, designated waste disposal facilities and specified processes.

3.3 Description of Environment

3.3.1 The bridge is located in a rural area to the south of Silver Mine Bay Beach and to the north of Mui Wo, Lantau. The bridge runs over Wang Tong River from north to south. To the west of the bridge is a woodland and the beach is located to the east. The immediate neighbour to the south is Silvermine Beach Resort and a village house with store to the north. Chung Hau and Wang Tong are the nearby villages. Its openness to Silver Mine Bay and the absence of industrial activities ensure good air quality in the Study Area.

3.3.2 The nearest EPD’s air quality monitoring (AQM) station is located at Tung Chung. However, air quality data from this station is considered inappropriate as the station is located next to the Hong Kong International Airport. Air quality data collected from the Tap Mun AQM station is more appropriate than data collected from Tung Chung AQM station, because both Tap Mun and the Project Site are considered as rural area. Therefore, data of Tap Mun AQM station are used to describe the existing air quality in the Study Area. The 1-hour, 8-hour, 24-hour and/or annual average concentrations of pollutants in the latest 5 years are presented in Table 3.2.

Table 3.2: Annual Average Concentration of Pollutants from Year 2011 to 2015 at EPD’s Air Quality Monitoring Station (Tap Mun)

Pollutant	Averaging Time	Concentration (mg/m³)							No. of Exceedance Allowed
Pollutant	Averaging Time	Year 2011	Year 2012	Year 2013	Year 2014	Year 2015	5-year average	AQO	No. of Exceedance Allowed
RSP	Annual	47	38	49	44	35	42.6	50	-
RSP	24-hour (10^th High)	95	87	119	102	86	97.8	100	9
FSP	Annual	31	25	30	27	24	27.4	35	-
FSP	24-hour (10^th High)	66	58	84	65	66	67.8	75	9
SO₂	Annual	10	11	13	9	7	10	N/A	-
	24-hour (4^th High)	32	21	29	24	14	24	125	3
	10-minute (4^th High)*	-	-	-	46	50	48	500	3
NO₂	Annual	12	11	11	10	10	10.8	40	-
NO₂	1-hour (19^th High)	58	56	79	61	51	61	200	18
O₃	Annual	71	71	75	72	73	72.4	N/A	-
O₃	8-hour (10^th High)	188	189	180	181	182	184	160	9
CO	Annual	752	697	664	589	657	672	N/A	-
	1-hour (1^st High)	1,490	1,680	1,530	1,370	2,140	1,642	30,000	0
	8-hour (1^st High)	1,459	1,608	1,441	1,329	1,351	1,438	10,000	0

Reference: http://epic.epd.gov.hk/EPICDI/air/station/?lang=en

http://www.aqhi.gov.hk/en/sub-download/sub-air-quality-reportse469.html?showall=&start=1

Exceeded values are underlined.

* AQO averaging time 10-minute data is not available in Years 2011 – 2013.

3.3.3 The 5-year average for all parameters complied with the respective AQO requirements except ozone (O₃). Ozone is a product of photochemical reactions of NOx and volatile organic compounds (VOCs) instead of being emitted directly from human activities. In the presence of NO_x(a common roadside pollutant), ozone will be broken down into oxygen. Since NO_x concentration in rural areas is low, ozone scavenging effect is small and results in generally high level.

3.3.4 Reference was also made from PATH data for the grid [22,28] that covers the area surrounding Wang Tong River Bridge (see Table 3.3 below) to give an indication on the predicted air quality at the subject area. The predicted air pollutant levels are comparable to the monitoring results in Table 3.2 except RSP and NO₂. The RSP level as shown in the PATH model is less than the recorded level in Tap Mun AQM station, whereas the NO₂ level shown in the PATH model is higher. Both predicted RSP and NO₂ values are well below AQO.

Table 3.3: Annual Average Concentration of Pollutants from Year 2016 to 2020 at Grid [22,28] from PATH model

Pollutant	Averaging Time	Concentration (mg/m³)							No. of Exceedance Allowed
Pollutant	Averaging Time	Year 2016	Year 2017	Year 2018	Year 2019	Year 2020	5-year average	AQO	No. of Exceedance Allowed
RSP	Annual	40	40	40	39	39	40	50	-
RSP	24-hour (10^th High)	88	88	88	88	87	88	100	9
FSP*	Annual	28	28	28	28	28	28	35	-
FSP*	24-hour (10^th High)	66	66	66	66	65	66	75	9
SO₂	Annual	10	9	9	9	8	9	N/A	-
	24-hour (4^th High)	29	28	28	28	27	28	125	3
	10-minute (4^th High)**	114	114	114	114	113	114	500	3
NO₂	Annual	19	19	18	17	16	18	40	-
NO₂	1-hour (19^th High)	100	96	93	90	86	93	200	18
O₃	Annual	65	66	67	68	68	67	N/A	-
O₃	8-hour (10^th High)	166	164	162	162	160	163	160	9
CO	Annual	224	222	219	217	214	219	N/A	-
	1-hour (1^st High)	997	995	994	993	992	994	30,000	0
	8-hour (1^st High)	829	820	817	816	814	819	10,000	0

Exceeded values are underlined.

* FSP was calculated based on RSP.

** 10 min (4^th High) SO₂ was calculated based on the 1 hour average SO₂ and stability class.

3.4 Air Sensitive Receivers

3.4.1 In accordance with Annex 12 of the EIAO-TM, any domestic premises, hotel, hostel, hospital, clinic, nursery, temporary housing accommodation, school, educational institution, office, factory, shop, shopping centre, place of public worship, library, court of law, sports stadium or performing arts centre are considered as air sensitive receivers (ASRs). Any other premises or places which, in terms of duration or number of people affected, with a similar sensitivity to the air pollutants as the aforementioned premises and places are also considered to be a sensitive receiver.

3.4.2 The Study Area for air quality impact assessment is defined by a distance of 500 meters from the boundary of the Project site, with consideration for extension to include major existing, planned and committed air pollutant emission sources identified to have a bearing on the environmental acceptability of the Project. A list of the identified ASR is tabulated in Table 3.4. Locations of the representative ASRs and the assessment points are shown in Figure 3.1.

Table 3.4: Representative Air Sensitive Receivers

ASR	Description	Land Use	Ground mPD	Shortest Horizontal Distance between ASR and the Boundary of the Project (m)	No. of Storey
ASR1	Silvermine Beach Resort	Hotel	4.2	5.5	3
ASR2	1 Tung Wan Tau Road	Village	3.7	5.5	2

3.5 Identification of Representative Air Pollutants

3.5.1 Air Pollutant Control Ordinance (APCO) (Cap 311) and EIAO-TM stipulate statutory Air Quality Objective (AQO) for 7 criteria air pollutants including NO₂, SO₂, FSP, RSP, CO, O₃ and lead.

Construction Phase

3.5.2 This Project involves demolition of an old bridge and construction of two new bridges. Works are planned to commence in July 2017 for completion by June 2019. Major potential air quality impacts during construction phase of the Project would be dust impact arising from:

· Materials handling;

· Dredging and disposal of excavated/dredged materials;

· Backfilling;

· Demolition;

· Bridge construction; &

· Wind erosion of open sites and stockpiling areas.

3.5.3 During the construction phase, dust would be generated inevitably from a number of construction activities such as excavation, backfilling, demolition and construction works. Since construction dust (i.e. TSP, RSP and FSP) will be generated by fore-mentioned works, TSP, RSP and FSP are considered as major air pollutants in construction phase. Unacceptable impacts from other criteria pollutants, i.e. NOx, SO₂, and CO, etc. are unlikely to occur as the number of diesel or petroleum fuelled machinery in the site shall be limited.

Operational Phase

3.5.4 Since proposed bridges are designed for pedestrians and cyclists instead of motorized vehicle, no traffic emission is expected during operation. Therefore, no air pollutants listed under the AQO shall be generated during the operational phase of the Project.

3.6 Assessment Methodology

3.6.1 This air quality impact assessment has included all proposed works and associated works mentioned in Section 2.1.4.

Construction Phase

3.6.2 Dust generation is the major air quality impact arising from the Project. Nevertheless, with proper implementation of mitigation measures, dust impact arising from the Project is considered insignificant due to the following:

· construction works will be confined in a small area;

· a slow work programme which avoid overlapping dust generating activities; &

· only 1-2 truck-trips per day would be sufficient for such small scale work and slow work programme (about 0.7m³ daily C&D material production)

3.6.3 While the Project boundary covered 2,954m², the construction work will be carried out within hoarding area (totalled 1,178m²) and at the proposed bridges, taking up around half of the project area in total (around 1,500m²). It should be emphasized that construction of cycle/pedestrian bridges and demolition of Old Bridge will be carried out in different phases. The coverage of the hoardings in each phase is shown in Figure 3.2. Referring to Appendix 2A, dust emitting activities from these works (such as mini-piling, sheet piling, excavation, concreting) will not be conducted concurrently. Therefore, limited number of plant equipment will be operated at one time. Also, less heavy construction method (minipiling instead of bored piling) has been proposed so that smaller PME will be adopted.

3.6.4 With slow work programme, the quantity of construction waste generated daily will be small such that 1-2 truck-trips will be sufficient to remove the waste from the Site. Without frequent material handling and truck movement, dust emission is expected to be small. Since the impact is expected to be insignificant, the impact will not be assessed quantitatively.

Concurrent Projects

3.6.5 As mentioned in Section 2.8.8, no project that involves heavy construction or dust emitting activity is known to be carried out concurrently with the construction work of this Project. Therefore, no cumulative air quality impact is expected.

Operation Phase

3.6.6 Since proposed bridges are designed for pedestrians and cyclists instead of motorized vehicle, no traffic emission is expected during operation and thus no operational air quality impact is anticipated.

3.7 Evaluation of Environmental Impacts

3.7.1 The construction of the Project would commence in July 2017 for completion in June 2019. According to the current construction programme, no cumulative dust impact with concurrent project is anticipated. Given the small scale of the Project (works area confined in around 1,500 m²), the amount of dust generated would not be significant. In addition, appropriate dust suppression measures as stipulated in “The Air Pollution Control (Construction Dust) Regulation” shall be implemented to minimize the impact. Details of mitigation measures recommended are summarized in Section 3.8 below.

3.8 Mitigation of Adverse Environmental Impacts

Mitigation of Potential Construction Dust Impact

3.8.1 Due to the scale of works of the Project, construction works are unlikely to cause unacceptable dust impact on surrounding sensitive receivers if standard control measures are implemented. Dust control measures as part of good construction practice should be implemented to minimize dust nuisance within acceptable level.

3.8.2 Dust impact could be effectively mitigated by inclusion of clauses for dust minimisation in the works contract. These dust minimisation clauses should be based on the Air Pollution Control (Construction Dust) Regulation, including but not limited to the followings:

· All stockpile of dusty materials shall be either entirely covered by impervious sheeting or stored in a three-side and top enclosed area. Alternatively, it should be sprayed with water or a dust suppression chemical to maintain the entire surface wet;

· All dusty materials shall be sprayed with water or a dust suppression chemical immediately prior to any loading, unloading or transfer operation to maintain dusty materials wet;

· Similar to storage of dusty materials, debris shall be either entirely covered by impervious sheeting or stored in a three-side and top enclosed area.

· Using water spray to wet the remaining dusty materials on the floor after removing stockpile. The surface of roads or streets shall be free from dust;

· Water or a dust suppression chemical shall be continuously sprayed on the surface where any pneumatic or power-driven drilling, cutting, polishing or other mechanical breaking operation is carried out, unless the process is accompanied by the operation of an effective dust extraction and filtering device;

· Dust suppression shall be applied to the working area immediately before, during and immediately after excavation or earth moving operation to keep the surface wet.

· Dust suppression shall be applied to the working area immediately before, during and immediately after site clearance (e.g. removal of trees, vegetation and structures) to keep the surface wet.

· All demolished items (e.g. trees, vegetation, structures, debris and rubbish) that may dislodge dust particles shall be covered entirely by impervious sheeting or placed in a three-side and top enclosed area within a day of demolition.

· Every stock of more than 20 bags of cement or dry pulverized fuel ash shall be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides;

· Cement bag shall be debagged, batched and mixed in a three-side and top enclosed area;

· Hoarding of at least 2.4m in height shall be erected along the construction site boundary adjoining the street except the site entrance;

· Exposed earth shall be properly treated within 6 months from completion of construction activities, e.g. by compacting, turfing, hydroseeding, vegetation planting or paving.

3.8.3 Due to small work site, localized work and slow work programme to reduce concurrent dust emitting activities, the proposed dust suppression measures and good site practices are considered sufficient to minimize dust impact on nearby ASRs. The mitigated TSP levels during construction phase should comply with the EIAO-TM guideline limit for all air sensitive receivers.

3.8.4 A control programme can be instigated to monitor the construction process in order to enforce dust controls and modify methods of works to reduce the dust emission down to acceptable levels.

3.9 Environmental Monitoring and Audit Requirements

3.9.1 With the implementation of good site practices and proposed dust suppression measures as mentioned in Section 3.8, no unacceptable air quality impact in construction phase is expected. Nevertheless, dust monitoring and audit programme will be required in construction phase to ensure that air quality impact is within acceptable level.

3.9.2 Since no air quality impact is expected in operational phase, no air quality monitoring is required in operational phase.

3.9.3 General EM&A requirements are presented in Chapter 9, while details of EM&A requirements such as monitoring locations, frequency of baseline and impact monitoring are presented in a separate EM&A manual.

3.10 Conclusion

3.10.1 Potential air quality impacts from the construction works of the Project would mainly be related to construction dust from site clearance, excavation, foundation and site formation works. With proper implementation of the recommended mitigation measures, it is anticipated that the project will not give rise to significant construction dust impacts likely to exceed the recommended limits in the TM at all ASRs. Adverse construction dust impact would not be anticipated.

4. Noise Impact

4.1 Introduction

4.1.1 This Chapter presents an assessment of the potential noise impact arising from the construction and operation of the Project. Mitigation measures have been proposed to alleviate the impact and their effectiveness has been evaluated.

4.2 Environmental Legislation, Standards and Guidelines

Construction Noise

4.2.1 This assessment is carried out according to criteria stipulated in Annexes 5 and 13 of Technical Memorandum on Environmental Impact Assessment Process (EIAO TM) for evaluating noise impacts.

4.2.2 The Noise Control Ordinance (NCO) (Cap. 400) provides the statutory framework for noise control in Hong Kong. Assessment procedures and standards are set out in the respective Technical Memoranda (TM) promulgated under the NCO. The following TMs are applicable to the assessment and control of construction noise.

· TM on Noise from Construction Work other than Percussive Piling (TM-GW);

· TM on Noise from Percussive Piling (TM-PP); and

· TM on Noise on Construction Work in Designated Areas (TM-DA)

4.2.3 Both percussive piling and construction work under restricted hours require a construction noise permit (CNP) in order to carry out such work. As the issuance of a CNP by the Noise Control Authority would depend on the compliance of percussive piling noise impact or construction noise impact with the limits set out within the TM-PP and TM-GW/TM-DA, the assessment of this type of noise would not be covered in the EIA report.

4.2.4 For construction, there is no statutory limit on daytime construction noise under the NCO and related TMs. Nevertheless, the EIAO-TM stipulates noise standards for daytime construction activities, as shown Table 4.1.

Table 4.1: Construction Noise Standards During Non-Restricted Hours

Uses	Noise Standards ^[1] , L_{eq (30 mins)} dB(A)
Uses	0700 to 1900 hours on any day not being a Sunday or general holiday	1900 to 0700 hours or any time on Sundays or general holiday
All domestic premises including temporary housing accommodation	75	(See Note 2)
Hotels and hostels	75
Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required	70/ 65 (During examinations)

Notes:

[1] The above standards apply to uses that rely on opened windows for ventilation.

[2] The criteria laid down in the relevant technical memoranda under the NCO for designated areas and construction works other than percussive piling may be used for planning purpose. A Construction Noise Permit (CNP) shall be required for the carrying out construction work during the period.

Construction Noise during Restricted Hours

4.2.5 The NCO provides statutory control on general construction works (excluding percussive piling) conducted during restricted hours (ie 1900 to 0700 hours (of the next day) from Monday to Saturday and at any time on Sundays or public holidays). A Construction Noise Permit (CNP) is required for carrying out of any general construction activities involving the use of any Powered Mechanical Equipment (PME) within restricted hours from the Authority under the NCO. The noise criteria and the assessment procedures for issuing a CNP are specified in the GW-TM under the NCO.

4.2.6 The use of Specified PME (SPME) and/or the undertaking of Prescribed Construction Work (PCW) within a Designated Area (DA) under the NCO during the restricted hours are controlled by the TM-DA. The relevant technical details in Technical Memorandum on Noise from Construction Work in Designated Areas (TM-DA) under NCO can be referred. The acceptable noise levels for construction during the restricted hours are summarized in Table 4.2 below.

Table 4.2: Construction Noise Standards during Restricted Hours

Uses	Acceptable Noise Level for Area Sensitive Ratings, dB(A)
Uses	A	B	C
All weekdays during the evening (1900 to 2300 hours), and general holidays (including Sundays) during the day and evening (0700 to 2300 hours)	60	65	70
All days during the night-time (2300 to 0700 hours)	45	50	55

4.2.7 The Area Sensitive Rating depends on the type of area and the degree of impact that Influencing Factors (Ifs) have on the NSR and is determined from Table 4.3 below. Industrial area, major road or the area within the boundary of Hong Kong International Airport shall be considered to be an IF.

Table 4.3: Area Sensitivity Ratings (ASRs)

Type of Area containing NSR	Degree to which NSR is affected by IF
Type of Area containing NSR	Not Affected	Indirectly Affected	Directly Affected
(i) Rural area, including country parks or village type developments	A	B	B
(ii) Low density residential area consisting of low-rise or isolated high-rise developments	A	B	C
(iii) Urban area	B	C	C
(iv) Area other than those above	B	B	C

4.2.8 According to the preliminary construction programme, it is very likely that the proposed construction works would be carried out during non-restricted hours only. For carrying out any general construction activity involving the use of any Powered Mechanical Equipment (PME) within restricted hours, a Construction Noise Permit (CNP) is required from the authority under the NCO. The noise criteria and the assessment procedures for issuing the CNP are specified in the GW-TM under the NCO. There is no guarantee that a CNP will be issued for the project construction. The Noise Control Authority will consider a well justified CNP application, once filed, for construction work within restricted hours as guided by the relevant TMs issued under the NCO. It is the Contractor’s responsibility to ensure compliance with the NCO and the relevant TMs in case of any construction activities during restricted hours.

4.2.9 Noise Control Ordinance (NCO) and Technical Memorandum on Environmental Impact Assessment Process have been followed for assessing the noise from powered mechanical equipment (PME) for different sensitive use.

Operational Noise

4.2.10 Since no fixed plant will be installed on the New Bridge which is for pedestrian and bicycle uses only, no operational noise is anticipated.

4.3 Description of Environment

4.3.1 The bridge is located in a rural area to the south of Silver Mine Bay Beach and to the north of Mui Wo, Lantau. The bridge runs over Wang Tong River from north to south. To the west of the bridge is a woodland and a beach is located to the east. The immediate neighbour to the south is Silvermine Beach Resort and a village house with store to the north. Chung Hau and Wang Tong are the nearby villages.

4.4 Identification of Potential Noise Impact

4.4.1 During the construction phase, use of powered mechanical equipment (PME) will inevitably generate construction noise and hence may cause noise nuisance to nearby residences. During operational phase, since no fixed plant will be installed and operated, no noise impact is anticipated.

4.5 Noise Sensitive Receivers

4.5.1 The Study Area covers 300m from the Project site. Given the proximity of the existing Wang Tong Bridge, noise sensitive receivers as defined in Annex 13 of EIAO-TM in the village are likely to be affected by the Project during its construction. Site visits have been carried out as part of the EIA to identify the NSR and representative worst impact point of the identified NSR. The location of the representative NSR is depicted in Figure 4-1 and listed in Table 4.4 below. Photographic record can be found in Appendix 4I.

Table 4.4: Representative Noise Sensitive Receiver

NSR	Description	Land Use	Ground mPD	Shortest Horizontal Distance between NSR (m)	No. of Storey
NSR1	1 Tung Wan Tau Road	Village	3.7	5.5	2

4.5.2 Silvermine Beach Resort uses central air-conditioning system for ventilation. Since it does not rely on opened window for ventilation, it is not considered as a noise sensitive receiver.

4.5.3 No planned or committed NSR is identified near the proposed New Bridge based on the best available information from Town Planning Board website (no Outline Zoning Plan (OZP), Development Permission Area Plans, Outline Development Plan, Layout Plan and any approved rezoning requests or section 16 applications for noise sensitive developments).

4.6 Assessment Methodology

Construction Schedule and Activities

4.6.1 The cycle bridge will be constructed first next to the Old Bridge. Then, the Old Bridge will be demolished. Finally, the pedestrian bridge will be constructed at the same location of the Old Bridge.

4.6.2 Phasing of the construction works has been identified. Works are categorized by construction methods. Both unmitigated and mitigated scenarios have been assessed for noise impact at the identified NSR.

Inventory of Noise Sources

4.6.3 Detailed construction method, sequence of work and the plant inventory in different work stages are proposed. Until a contractor is appointed, full details of the type and utilisation of construction plants will not be known exactly. Typical types and number of powered mechanical equipment (PME) needed for various construction activities for the construction of the Project have been assigned as shown in Appendix 4A. PME that will likely be used concurrently have been grouped within the same works stage.

4.6.4 Plant inventory and construction programme for the Project as in Appendices 4A and 4B respectively for various construction activities were developed by the Project Engineer. It should be noted that not every PME will operate all the time when they are on site. Therefore a typical % on time is assumed for each PME based on experience in actual site practice, so that the noise prediction would be realistic. Consequently, the effective sound power levels for each construction activity can be quantified and listed in Appendices 4A and 4B.

4.7 Evaluation of Environmental Impacts

Prediction of Construction Noise Impact

4.7.1 The impact of construction noise on the identified NSR has been assessed in accordance with the procedures laid down in Technical Memorandum on Noise from Construction Work Other Than Percussive Piling.

4.7.2 The Unmitigated Powered Mechanical Equipment (PMEs) and its Sound Power Level (SWL), Detailed Calculation and Summary of the Construction Noise of the Project are provided in Appendices 4A – 4D. The location of NSR and notional noise sources of the Project can be found in Figure 4.1.

4.7.3 The unmitigated construction noise impact on the selected NSR is shown in Table 4.5. The unmitigated construction noise levels at NSR exceeds the noise criteria by 9 dB(A).

Table 4.5: Unmitigated Construction Noise Impact, dB(A)

NSR	Land Use	Predicted Maximum Noise Level from the Project, dB(A)	Noise Criteria, dB(A)	Exceedance, dB(A)
NSR1	Village	84	75	9

Bolded figures mean exceedance of relevant noise criteria

4.7.4 Based on the effective sound power level of the PMEs and the distance of works site to the noise sensitive receivers, unmitigated construction noise level for some work stages are likely to exceed the 75dB(A) guideline level for the non-restricted hours.

Cumulative Impact

4.7.5 According to Section 2.8, although there are one planned and one ongoing projects within the Study Area, no project that involves heavy construction activity is known to be carried out concurrently with the construction work of this Project. Therefore, no cumulative impact is expected.

4.7.6 Construction noise disturbance is temporary and the New Bridge will not cause operational noise impact. As there is no change of land use at the Site (bridge), no noise constraint will be incurred due to this Project.

4.8 Evaluation and Recommendation of Mitigation Measures for Noise

4.8.1 Mitigation at source or path should be the most effective way to reduce the impact. There are 3 ways in doing that viz: -

· by use of quiet plants and working methods to mitigate at source;

· by use of mobile noise barriers along the path of noise propagation;

· by good site practice to limit noise emissions at source;

4.8.2 Silenced plants or quality powered mechanical equipment (QPME) are quieter than those noise levels given in TM-GW for the equivalent type of equipment. These silenced equipment are known to be available in Hong Kong and should be adopted as far as possible.

4.8.3 Mobile noise barriers can effectively screen noise from reaching sensitive receivers, particularly for the low-rise houses in this case. 3m high mobile barriers with skid footing and a small cantilevered upper portion can be located within a few metres from stationary plants and about 5m from mobile plants such as hydraulic breaker. Since all PME involved in this Project are either slow moving or stationary during operation, frequent adjustment on the position of mobile barriers will not be required.

4.8.4 Good site practice and noise management can significantly reduce the construction noise impact on nearby NSR. Although the reduction in noise level is not readily predictable and quantified, the following measures should be useful during each phase of construction:

· Machines that may be in intermittent use should be shut down between work periods or should be throttled down to a minimum;

· Silencer and mufflers on construction equipment should be utilised and should be properly maintained during the construction programme;

· Noisy activities can be scheduled to minimise exposure of nearby NSR to high levels of construction noise. For example, noisy activities can be scheduled in midday;

· For the demolition of the existing bridge, hand-held breaker may be used to break the hard concrete layer. Manual equipment should be used as far as practicable to avoid using PME. If found necessary, the percentage on time should be limited as possible to avoid unnecessary disturbance;

· Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from the nearby NSR;

· Mobile plant should be sited as far away from NSR as possible; and

· Material stockpiles and other structures should be effectively utilised, wherever practicable, in screening noise from on-site construction activities.

4.8.5 “Recommended Pollution Control Clauses for Construction Contracts” is available on EPD website. It contains recommended noise pollution control measures to be implemented by the contractor during construction.

4.8.6 With the use of quality PMEs and movable noise barriers, the predicted construction noise level at the representative NSR is shown in Table 4.6 below. The mitigated powered mechanical equipment (PMEs) and its sound power level (SWL), detailed calculation and summary of the construction noise level of the Project are provided in Appendices 4E – 4H. Results indicated that predicted construction noise levels at all NSR are complied with the recommended noise criteria in EIAO-TM.

Table 4.6: Mitigated Construction Noise Impact, dB(A)

NSR	Land Use	Predicted Maximum Noise Level from the Project, dB(A)	Noise Criteria, dB(A)	Exceedance, dB(A)
NSR1	Village	72	75	-

Bolded figures mean exceedance of relevant noise criteria

4.9 Evaluation of Residual Impacts

4.9.1 All practical and feasible mitigation measures have been proposed, such as adopting QPME, movable noise barriers and temporary noise barriers. According to Table 4.6, there is no exceedance of the mitigated construction noise of the Project on the NSR. No residual impact was anticipated during construction phase.

4.9.2 As there is no fixed plant operated, no unacceptable operational noise impact is anticipated.

4.10 Environmental Monitoring and Audit Requirements

4.10.1 With implementation of mitigation measures such as adoption of good site practice, use of quieter PMEs and mobile noise barrier, no unacceptable construction noise impact is anticipated. Regular noise monitoring will be proposed at representative NSR to ensure that relevant noise standard can be met. Details of monitoring requirements such as monitoring locations, frequency of baseline and impact monitoring shall be prepared in the form of EM&A manual as part of the EIA submission.

4.10.2 A hotline is proposed to set-up by the contractor(s) to service complaint from the NSR in the vicinity about the adverse construction noise produced from the Project.

4.10.3 As there is no fixed plant provided for the Project, no unacceptable operational noise impact is expected. Operational noise monitoring is considered unnecessary.

4.10.4 General EM&A requirements were presented in Chapter 9.

4.11 Conclusion

4.11.1 Typical types and number of powered mechanical equipment (PME) needed for various construction activities for the construction of bridges have been assessed. Based on the effective sound power level of the PMEs and the distance of work site to the noise sensitive receiver, unmitigated construction noise level would exceed the 75dB(A) guideline level for the non-restricted hours for the NSR. At source mitigation measures have been proposed including the use of quality plants, use of mobile noise barriers, and good site practice for implementation. With the proposed mitigation measures, construction noise impact on the representative noise sensitive receiver are predicted to comply with the criteria in “Construction Noise Standards During Non-Restricted Hours” stipulated in EIAO-TM.

4.11.2 With all the proposed mitigation measures, no residual construction noise impacts are anticipated. Moreover, regular noise monitoring should be carried out and a hotline to service any complaint should be set up in construction phase.

4.11.3 As no fixed plant will be installed and operated in operational phase, no unacceptable operational noise impact is anticipated.

5. Water Quality Impact

5.1 Introduction

5.1.1 This Chapter presents an assessment of the potential water quality impact arising from the construction and operation of the Project. Mitigation measures have been identified to alleviate the impact and their effectiveness has been evaluated.

5.2 Environmental Legislation, Standards and Guidelines

Technical Memorandum on Environmental Impact Assessment Process:

5.2.1 This assessment is carried out according to criteria stipulated in Annexes 6 and 14 of Technical Memorandum on Environmental Impact Assessment Process (EIAO TM) for evaluating water quality impact.

Water Pollution Control Ordinance (Cap. 358):

5.2.2 The Water Pollution Control Ordinance (Cap. 358) is the major legislation relating to the protection and control of water quality in Hong Kong. According to the Ordinance and its subsidiary legislation, Hong Kong waters are divided into ten water control zones (WCZ). Corresponding statements of Water Quality Objectives (WQO) are stipulated for different water regimes (marine waters, inland waters, bathing beaches subzones, secondary contact recreation subzones and fish culture subzones) in each of the WCZ based on their beneficial uses. The assessment area in this Project covers the Southern WCZ. The corresponding WQOs are listed in Table 5.1.

Table 5.1: Summary of Water Quality Objectives for Southern WCZ

Parameter	Water Quality Objective	Sub-Zone
Aesthetic Appearance	ü There should be no objectionable odours or discolouration of the water. ü Tarry residues, floating wood, articles made of glass, plastic, rubber or of any other substances should be absent. ü Mineral oil should not be visible on the surface. ü Surfactants should not give rise to a lasting foam. ü There should be no recognisable sewage-derived debris. ü Floating, submerged and semi-submerged objects of a size likely to interfere with the free movement of vessels, or cause damage to vessels, should be absent. ü The waters should not contain substances which settle to form objectionable deposits.	Whole zone
Bacteria	ü Annual geometric mean level of Escherichia coli not to exceed 610 cfu/100mL for secondary contact recreation subzones and fish culture zones. ü Geometric mean level of E. coli of all samples collected from March to October exclusive not to exceed 180 per 100mL for bathing beaches.	ü Secondary Contact Recreation Subzones & Fish Culture Zones ü Bathing Beach Subzones
Dissolved Oxygen (DO)	ü Bottom dissolved oxygen not less than 2 mg/L for 90% of samples; ü Depth-averaged dissolved oxygen not less than 4 mg/L for 90% of samples.	Whole zone
pH	In the range 6.5 - 8.5, change due to waste discharge not to exceed 0.2.	Whole zone
Temperature	Change due to waste discharge not to exceed 2°C.	Whole zone
Salinity	Change due to waste discharge not to exceed 10% of natural ambient level.	Whole zone
Suspended solids (SS)	Waste discharge not to raise the natural ambient level by 30% nor cause the accumulation of suspended solids which may adversely affect aquatic communities.	Marine waters of the whole zone
Ammonia	Annual mean of un-ionized ammonia nitrogen not to exceed 0.021 mg/L, calculated as the arithmetic mean.	Whole zone
Nutrients	Annual mean depth-averaged total inorganic nitrogen (TIN) not to exceed 0.1mg/L.	Whole zone
Toxins	Not to be present at levels producing significant toxic effect.	Whole zone

Source: Statement of Water Quality Objectives (Southern Water Control Zone)

Practice Notes

5.2.3 A practice note (PN) for professional persons was issued by the EPD to provide environmental guidelines for the handling and disposal of construction site discharges. The Practice Note (PN) for Professional Persons on “Construction Site Drainage” (ProPECC PN 1/94) issued by EPD provides good practice guidelines for dealing with ten types of discharge from a construction site. These include surface runoff, groundwater, boring and drilling water, bentonite slurry, water for testing and sterilisation of water retaining structures and water pipes, wastewater from building constructions, acid cleaning, etching and pickling wastewater, and waste water from site facilities. Practices outlined in the ProPECC PN 1/94 should be followed as far as possible during construction to minimize the water quality impact due to construction site drainage.

5.2.4 Assessment criteria for Corals is also covered in this EIA. According to the study by Pastororok & Bilyard ^{^[1]} and Hawker & Connel ^{^[2]}on coral reef, the sedimentation rate should be less than 0.1kg/m²/day for avoiding unacceptable impact to coral. The WQO for SS (less than 30% of ambient baseline condition) is also valid to corals.

5.3 Description of the Environment

5.3.1 The project site is located within Southern Water Quality Control Zone (WCZ). The water quality in this WCZ was rated as “good” in 2013 for its high dissolved oxygen, low nutrients (total inorganic nitrogen) and E. coli levels ^{^[3]}. The compliance rate of water quality objectives was reduced in 2012 due to exceedance in total inorganic nitrogen ^{^[4]}. This was probably caused by higher background TIN level under the influence of Pearl River discharge ⁴. The nearest water quality monitoring station maintained by EPD is SM11. It is located between Hei Ling Chau and Silver Mine Bay, about 3 km from Mui Wo. The latest 5 years water qualities at SM11 are summarized in the Table 5.2.

Table 5.2: Water Quality Monitoring Results at SM11 from 2009 to 2013

Parameters	2009	2010	2011	2012	2013	Mean
pH	8.1	7.9	7.9	7.9	8	8.0
pH	(7.9 - 8.4)	(7.7 - 8.3)	(7.6 - 8.4)	(7.6 - 8.2)	(7.7 - 8.4)	-
Salinity (psu)	30.6	30	31	29.3	29.6	30.1
Salinity (psu)	(26.0 - 33.3)	(24.7 - 33.1)	(26.5 - 32.9)	(23 - 32.6)	(23.9 - 33.4)	-
Turbidity (NTU)	6.9	5.1	5.7	5.6	3.8	5.42
Turbidity (NTU)	(1.6 - 13.1)	(2.1 - 11.2)	(2.1 - 11.7)	(1.1 - 12.3)	(1.1 - 8.1)	-
Temperature (°C)	24.3	23.8	23.3	23.9	23.9	23.8
Temperature (°C)	(16.6 - 28.9)	(16.9 - 28.6)	(16.5 - 29.3)	(16.4 - 29.8)	(18.1 - 28.6)	-
Suspended Solids (mg/L)	7.3	6.2	7.9	6.3	4.9	6.5
Suspended Solids (mg/L)	(2.0 - 15.7)	(2 - 12.3)	(3.3 - 15.3)	(2.2 - 11.7)	(0.8 - 12)	-
DO (mg/L) Depth Average	6.3	6.9	6.8	8.2	7.1	7.1
DO (mg/L) Depth Average	(5.0 - 7.8)	(3.4 - 9.2)	(3.1 - 9.1)	(6.4 - 11.6)	(5.2 - 9.4)	-
DO (mg/L) Bottom	6	5.9	6.5	7.8	6.5	6.5
DO (mg/L) Bottom	(4.5 - 7.8)	(0.5 – 7.9)	(3.2 – 9.2)	(6.3 - 10.1)	(4.2 - 8.0)	-
DO (%saturation) Depth Average	89	97	94	114	100	99
DO (%saturation) Depth Average	(69 - 115)	(52 - 138)	(45 - 137)	(91 - 172)	(74 - 136)	-
DO (%saturation) Bottom	85	82	90	108	90	91
DO (%saturation) Bottom	(67 - 116)	(8 - 109)	(46 - 133)	(91 - 145)	(62 - 108)	-
Total Inorganic Nitrogen (mg/L)	0.25	0.321	0.322	0.377	0.326	0.319
Total Inorganic Nitrogen (mg/L)	(0.12 - 0.40)	(0.133 - 0.473)	(0.093 - 0.583)	(0.15 - 0.87)	(0.143 - 0.62)	-
Ammonia Nitrogen (mg/L)	0.068	0.086	0.104	0.081	0.064	0.081
Ammonia Nitrogen (mg/L)	(0.03 - 0.113)	(0.035 - 0.187)	(0.03 - 0.193)	(0.023 - 0.177)	(0.029 - 0.1)	-
Unionised Ammonia (mg/L)	0.004	0.003	0.003	0.002	0.003	0.003
Unionised Ammonia (mg/L)	(0.001 - 0.011)	(0.001 - 0.006)	(0.001 - 0.008)	(0.001 - 0.005)	(0.001 - 0.007)	-
Nitrite Nitrogen (mg/L)	0.033	0.043	0.032	0.045	0.046	0.040
Nitrite Nitrogen (mg/L)	(0.014 - 0.110)	(0.008 - 0.085)	(0.006 - 0.075)	(0.007 - 0.092)	(0.009 - 0.107)	-
Nitrate Nitrogen (mg/L)	0.15	0.192	0.185	0.251	0.216	0.199
Nitrate Nitrogen (mg/L)	(0.050 - 0.293)	(0.055 - 0.367)	(0.038 - 0.397)	(0.098 - 0.717)	(0.077 - 0.477)	-
Total Kjeldahl Nitrogen (mg/L)	0.23	0.25	0.246	0.291	0.238	0.251
Total Kjeldahl Nitrogen (mg/L)	(0.17 - 0.35)	(0.19 - 0.347)	(0.103 - 0.313)	(0.213 - 0.38)	(0.15 - 0.343)	-
Total Nitrogen (mg/L)	0.42	0.486	0.464	0.587	0.501	0.492
Total Nitrogen (mg/L)	(0.25 - 0.57)	(0.25 - 0.733)	(0.163 - 0.723)	(0.367 - 1.057)	(0.237 - 0.917)	-
Orthophosphate Phosphorus (mg/L)	0.013	0.015	0.016	0.016	0.013	0.015
Orthophosphate Phosphorus (mg/L)	(0.004 - 0.026)	(0.002 - 0.038)	(0.002 - 0.029)	(0.003 - 0.031)	(0.004 - 0.033)	-
Total Phosphorus (mg/L)	0.04	0.033	0.039	0.034	0.038	0.037
Total Phosphorus (mg/L)	(0.02 - 0.05)	(0.02 - 0.047)	(0.02 - 0.057)	(0.02 - 0.053)	(0.03 - 0.057)	-
Silica (mg/L)	0.92	0.9	1	1	1.2	1.00
Silica (mg/L)	(0.58 - 1.63)	(0.5 - 1.8)	(0.1 - 2)	(0.1 - 1.4)	(0.4 - 2.2)	-
BOD5 (mg/L)	1.1	1.2	1	0.9	0.9	1.02
BOD5 (mg/L)	(0.2 - 1.9)	(0.3 - 2.5)	(0.2 - 2.6)	(0.1 - 2.5)	(0.3 - 2.3)	-
Chlorophyll-a (μg/L)	5.9	9.9	5.7	8.8	7.2	7.5
Chlorophyll-a (μg/L)	(1.9 - 16.7)	(1.1 - 33)	(1.6 - 21.7)	(0.7 - 28.3)	(1.3 - 25.7)	-
E. coli (cfu/100mL)	3	2	2	2	2	2.2
E. coli (cfu/100mL)	(1 - 18)	(1 - 9)	(1 - 8)	(1 - 13)	(1 - 6)	-
Faecal Coliforms (cfu/100mL)	6	5	3	3	5	4.4
Faecal Coliforms (cfu/100mL)	(1 - 61)	(1 - 38)	(1 - 16)	(1 - 28)	(1 - 22)	-

Silvermine Bay Beach

5.3.2 As Silver Mine Bay Beach is located within the study area in this project, the baseline water quality review also covers the latest 5 years water quality of the beach monitored by EPD, which are shown in Table 5.3.

Table 5.3: Beach Water Quality Monitoring Results at Silver Mine Bay Beach from 2009 to 2013

Parameter	2009	2010	2011	2012	2013
pH	8.3	8.4	8.3	8.3	8.27
pH	(8.0 - 8.8)	(8.0 - 8.9)	(8.0 - 8.6)	(7.8 - 8.8)	(8.01 - 8.62)
Salinity (psu)	26.00	25.2	27.00	24.0	23.4
Salinity (psu)	(14.6 - 32.6)	(7.6 - 32.6)	(11.6 - 32.0)	(3.8 - 31.7)	(10.3 - 31.1)
Turbidity (NTU)	12.6	11.6	12.3	11.4	7.17
Turbidity (NTU)	(4.3 - 60.5)	(3.5 - 56.5)	(3.1 - 49.0)	(3.4 - 31.4)	(1.5 - 25.3)
Temperature (^oC)	27.7	27.5	27.2	27.7	27.4
Temperature (^oC)	(19.5 - 34.0)	(18.5 - 32.5)	(16.9 - 33.0)	(16.9 - 33.2)	(19.0 - 33.1)
Dissolved Oxygen	6.7	6.6	6.6	6.8	6.9
Dissolved Oxygen	(3.9 -9.5)	(4.4 - 8.7)	(4.5 -8.0)	(4.2 - 9.8)	(5.0 - 8.3)
E.coli (no./100 ml)	45	31	28	38	39

5.3.3 Based on Table 5.2, the Geometric mean of E. coli at SM11 in the latest five years well complied with the WQO (180 cfu/100ml for bathing beach and 610 cfu/100ml for fish culture zone). It may be partially as a result of the location of the monitoring far away from the shoreline and therefore human impact source. Besides, the E. coli in the beach is also well below the criteria indicating the baseline water is generally low with E. coli.

5.3.4 For Silver Mine Bay Beach, the annual averaged DO level complies with the WQO (depth-average DO > 4 mg/l). On the other hand, at SM11, the depth averaged DO in 2010 and 2011 have been recorded lower than the WQO requirement even the annual average are in compliance with the WQO. The monitoring results show a wide variation in DO for each year.

5.3.5 For unionized ammonia, which is toxic to fishes, the monitoring results at SM11 are much lower than the WQO (0.021 mg/l).

5.3.6 The indicator of algae bloom, TIN level, has been recorded exceeding WQO (0.1 mg/l) at SM11 for 5 years. A high risk appears in the past few years and the minimum record are higher than WQO for four years.

Wang Tong River

5.3.7 EPD conducts monthly water quality monitoring at five river monitoring stations in Mui Wo, one of which is in the middle reach of Wang Tong River near human settlement (MW5). While the Water Quality Index grading of MW5 was in the range of Good to Excellent, the average E. coli levels was 3,900 cfu/100ml in 2013, showing pollution from domestic discharge. The latest 5 years key water quality parameters of MW5 monitored by EPD are shown in Table 5.4 below.

Table 5.4: Summary of Water Quality Monitoring data for Middle Reach of Wang Tong River (MW5) from 2009 to 2013

Year	Key Water Quality Parameters
Year	pH	5-Day BOD (mg/L)	COD (mg/L)	SS (mg/L)	DO (mg/L)
WQO Criteria	6.0 - 9.0	<5	<30	<25	>4
2009	7.1	2	9	7	7.1
2009	(6.9 - 7.6)	(<1 - 5)	(4 - 15)	(2 - 20)	(5.4 - 8.4)
2010	7.3	2	9	8	7.2
2010	(7.0 - 7.8)	(<1 - 5)	(4 - 15)	(2 - 36)	(5.9 - 8.8)
2011	7.3	2	11	7	7
2011	(7.0 - 8.2)	(<1 - 4)	(6 - 17)	(1 - 14)	(5.3 - 10.5)
2012	7.3	1	8	6	7.4
2012	(7.0 - 8.1)	(<1 - 5)	(3 - 19)	(2 - 27)	(5.4 - 8.3)
2013	7.2	1	7	4	7.6
2013	(6.9 - 9.8)	(<1 - 7)	(3 - 16)	(3 - 14)	(6.4 - 9.8)

Notes: 1. Data presented are in annual medians of monthly samples

2. Figures in brackets are annual ranges.

3. Values at or below laboratory reporting limits are presented as laboratory reporting limits

4. Equal values for annual medians (or geometric means) and ranges indicate that all data are the same as or below laboratory reporting limits

5.3.8 The average values of the key water quality parameters in the recent 5 years mostly complied. However, occasional exceedance of suspended solids was recorded in 2010 and 2012. Exceedance of pH and 5-day BOD was recorded in 2013.

5.4 Water Sensitive Receivers

5.4.1 Water sensitive receivers (WSR) likely to be affected by the Project within 500m study boundary were identified from on-site visits and surveys:

· Wang Tong River

· Silver Mine Bay Beach

· Silver Mine Bay

· River Silver

· Secondary contact recreation sub-zones

5.4.2 The locations of these sensitive receivers are shown in Figure 5.1.

5.5 Assessment Methodology

5.5.1 The construction sequence and method of the Project were reviewed to identify the potential water quality pollution source. Considering the direction of water flow in the region, the potential dispersion of pollutants was predicted and the degree of impact on the WSRs was evaluated. The bridge design was evaluated to identify any operational water quality impact in terms of hydrology. Mitigation measures were proposed to avoid and minimize the impact to acceptable level where necessary.

5.6 Identification, Prediction and Evaluation of Water Quality Impact

Construction Phase

5.6.1 The water quality in the receiving water bodies may be affected by:

· Construction and Demolition Works

· Surface runoff

· Accidental leakage/spillage

· Sewage from workforce

5.6.2 Given the small project scale, the amount of pollutants generated from above is expected to be limited. With great distance of River Silver from the Site, the suspended solids would have been well dispersed and no water quality impact on River Silver is expected.

Construction and Demolition Works

5.6.3 Excavation/dredging is required for establishing new bridges abutments and column along the high water mark, and demolishing existing bridge column within water. Without proper enclosure, excavated materials or sand may fall into the river and being carried into Silvermine Bay during low tide or being washed upstream of Wang Tong River. This may lead to increase in suspended solid level, turbidity and reduce dissolved oxygen level in water.

5.6.4 Cofferdam is proposed to fully surround the excavation/dredging location at the new and old pier and abutment that falls with high water mark. The cofferdam shall be installed by vibrating action to minimize disturbance to the sandy shore and riverbed. The cofferdam will act as a water-tight container to stop water from entering or leaving the work site. Wastewater shall be pumped out for treatment up to standard stipulated in the wastewater discharge license. The cofferdam can only be removed when the construction work is completed.

5.6.5 Since part of the working area will encroach Wang Tong River for establishing new bridges abutments and demolishing existing bridge column, the hydrodynamic in Wang Tong River might be changed. Nevertheless, the working area will not block the River in both low and high tide, and the working area will only impact on the river for short term (about 9 months for each bridge in construction phase only). Also, excavated area will be backfilled to original level and thus there will be no alteration of bathymetry.

5.6.6 Similarly, debris generated from construction and demolition of bridges above water may pose risk to water deterioration. Therefore, a solid working platform with toe board would be erected above Wang Tong River underneath the working areas, in order to prevent construction material, waste and/or scraps dropping into the river.

5.6.7 By working within enclosed area and with temporary platform above water, potential of falling of objects into the river can be minimized. The proposed layout of cofferdam is shown in Figure 2.4. No unacceptable water quality impact is expected.

Surface Runoff

5.6.8 Exposed soil after earthworks and stockpiling of demolished, excavated and construction materials near waterfront may be blown away by wind or washed into the river under heavy rain. The good site practices in Section 5.7 below (such as removal of unnecessary materials, provision of storage area away from the shore) shall be implemented to minimize potential surface runoff.

5.6.9 In addition, an impermeable cover (e.g. tarpaulin) shall be erected above the working platform of the bridges to prevent rainwater from falling into the working area. This can minimize surface runoff from the platform.

5.6.10 Also, various construction activities may generate wastewater directly. These include general cleaning and polishing and dust suppression. These types of wastewater would contain high concentration of suspended solids. The wastewater shall be effectively collected by designing drainage system around site boundary for treatment before discharge.

Accidental Leakage/Spillage

5.6.11 Chemicals (such as paint), fuel and lubricating oil for plant equipment may be stored and used onsite. Water deterioration may be resulted from accidental leakage/spillage during the demolition and construction of the bridges directly into the receiving water body or being carried down by construction site runoff. Nevertheless, there should be no immerse need for chemical or oil in this small scale project. The quantity stored or used onsite should be limited to exert a significant water quality impact in case of leakage. Good site practice in Section 5.7 shall be implemented to minimize the chance of happening.

Sewage from Workforce

5.6.12 Uncontrolled sewage discharge from workers may also pollute the water in the river. Increased nutrient level from contaminated discharges and sewage from workforce could also lead to a number of secondary water quality impacts including localized increase in ammonia and nitrogen concentrations.

5.6.13 There are public toilets that can be used by the workers. Alternatively, portable chemical toilets shall be provided if necessary. It shall be placed away from water and maintained by registered waste collector. No significant water quality impact due to sewage from workforce is expected.

Cumulative Impact

5.6.14 According to Section 2.8, although there are one planned and one ongoing projects within the Study Area, no project that involves heavy construction activity is known to be carried out concurrently with the construction work of this Project. Therefore, no cumulative impact is expected.

Operational Phase

5.6.15 Since no new column will be established in the Wang Tong River, the flow of River will not be blocked by the Project. As the Old Pier is not wide, removal of the pier is not expected to bring significant change in hydrodynamics of the river. Besides, as the Project will not generate wastewater, no water quality impact is expected in operational phase.

5.7 Mitigation Measures

Construction Phase

Works in High Water Mark and above Water

5.7.1 Excavation/dredging works shall be carried out inside the watertight cofferdam, which should be formed by installing sheet piles by vibratory action. The cofferdam can only be removed after completion of work. Water removed from the cofferdam should be desilted before discharge back into the sea. Similar mitigation measure has been applied in dredging/excavation and seawall modification for the construction of piers/pier foundations of the railway bridge in Aberdeen Channel^{^[5]}. Based on the routine water quality monitoring record, no exceedance in action/limit level was found due to the project.

5.7.2 A solid working platform with toe board would be erected above Wang Tong River underneath the working areas, in order to prevent construction material, waste and/or scraps dropping into the River. In addition, an impermeable cover (e.g. tarpaulin) shall be erected above the working platform of the bridges to prevent rainwater from falling into the working area. This can minimize surface runoff from the platform.

Good Site Practices

5.7.3 Good practices should be followed as far as possible. The mitigation measures should include, but not limited to, the following measures:

· Perimeter channels and catchpits shall be constructed prior to commencement of site formation works and earthworks;

· Removal facilities (sand traps, silt traps and sediment basins) should be provided to collect the surface run-off from construction sites. Channel or earth bund or sand bag barriers should be provided to direct the stormwater to removal facilities;

· The silt removal facilities, channels and manholes should be maintained regularly;

· Works program should be designed to avoid demolishing the Old Bridge and to minimize the scale of soil/sand excavation during the rainy season (April to September) as far as possible;

· Works program should be well designed to minimize the work areas to minimize the soil exposure and site runoff;

· To avoid the surface runoff from the earthwork, the exposed soil area should be ensured to be installed with surface protection measure such as covering by tarpaulin before arrival of rainstorm;

· Minimize exposed earth after completion of work in a certain area by hydroseeding, vegetating, soil compacting or paving;

· Protect temporary access roads by crushed stone or gravel;

· Prevent rainwater from entering trenches. Excavation of trenches should be dug and backfilled in short sections during rainy seasons. Remove silt in rainwater collected from the trenches or foundation excavations prior to discharge to storm drains.

· Open stockpiles of construction materials (e.g. aggregates, sand and fill material) on sites should be covered with tarpaulin or similar fabric during rainstorm;

· All plant and vehicles should be washed before they leave the site. The wash-water should have sand and silt settled out or removed before discharging into storm drain;

· Any wastewater generated from the construction works should undergo the removal of settleable solids in a silt removal facility;

· Remove waste from the site regularly to prevent waste accumulation and chance of wash-off.

· Provide sufficient chemical toilets with regular maintenance by licensed chemical waste collector where necessary

Prevention of Pollution from Chemicals

· Register as chemical waste producer if chemical waste will be generated.

· Perform maintenance of vehicles and equipment that have oil leakage and spillage potential on hard standings within a bunded area with sumps and oil interceptors.

· Dispose chemical waste in accordance to Waste Disposal Ordinance. Follow the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes, examples as follows:

i. Store chemical wastes at designated safe location with adequate space

5.8 Evaluation of Residual Impacts

5.8.1 With proper implementation of mitigation measures, no unacceptable residual impact is anticipated during construction phase. No operational phase water quality impact is anticipated.

5.9 Environmental Monitoring and Audit Requirements

5.9.1 Regular monitoring of water quality should be carried out at water quality monitoring stations at impact stations downstream to the construction site and at control stations upstream of construction site before and throughout dredging work. Detailed EM&A requirement are provided in EM&A Manual.

5.10 Conclusion

5.10.1 Potential water quality impacts arising from the construction activities are expected from falling of debris above water and leakage of debris from cofferdam in water during demolition of Old Bridge and construction of New Bridge, site runoff of exposed soil, earthworks and stockpiles during rainstorms and sewage generated from construction workforce. These would be minimized by implementing appropriate mitigation measures and good site management practices. No unacceptable water quality impact is expected.

6. Waste Management Implication and Land Contamination

6.1 Introduction

6.1.1 This Chapter identifies the types of wastes that are likely to be generated during the construction and operation of the Project, and evaluates the potential environmental impacts that may result from these wastes.

6.2 Relevant Legislations, Standards & Guidelines

6.2.1 Reference has been made to the following Ordinances and Regulations which are relevant to waste management and disposal:

· The Waste Disposal Ordinance (Cap. 354) and subsidiary legislation such as the Waste Disposal (Chemical Waste) (General) Regulation and Waste Disposal (Charges for Disposal of Construction Waste) Regulation that set out requirements for the storage, handling and transportation of all types of wastes.

· Environmental Impact Assessment Ordinance (Cap. 499), Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annexes 7 and 15;

· Public Health and Municipal Services Ordinance (Cap. 132) – Public Cleansing and Prevention of Nuisance Regulation – control of disposal of general refuse;

· Land (Miscellaneous Provisions) Ordinance (Cap. 28); and

· Dumping at Sea Ordinance (Cap. 466).

6.2.2 Other relevant documents and guidelines that are applicable to waste management and disposal in Hong Kong include:

· Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992);

· Development Bureau Technical Circular (Works) (TC(W)) No. 6/2010, Trip Ticket System for Disposal of Construction & Demolition Materials;

· Development Bureau TC(W) No. 8/2010 Enhanced Specification for Site Cleanliness and Tidiness;

· ETWB TC(W) No. 19/2005, Environmental Management on Construction Sites;

· ETWB TC(W) Nos. 22/2003 and 22/2003A, Additional Measures to Improve Site Cleanliness and Control Mosquito Breeding on Construction Sites;

· ETWB TC(W) No. 33/2002, Management of Construction and Demolition Material Including Rock;

· ETWB TC(W) No. 34/2002, Management of Dredged / Excavated Sediment;

· Works Bureau TC No. 12/2002, Specification Facilitating the Use of Recycled Aggregates;

· Works Bureau TC Nos. 25/99, 25/99A and 25/99C, Incorporation of Information on Construction and Demolition Material Management in Public Works Sub-committee Papers; and

· Works Bureau TC No. 2/93, Public Dumps.

6.2.3 Legislations and guidelines related to land contamination are given below:

· Environmental Impact Assessment Ordinance (Cap. 499), Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annex 9;

· Waste Disposal (Chemical Waste) (General) Regulation (Cap 354C)

· Dangerous Goods Ordinance (Cap 295)

· Practice Guide for Investigation and Remediation of Contaminated Land;

· Guidance Note for Contaminated Land Assessment and Remediation; and

· Guidance Manual for Use of Risk-Based Remediation Goals (RBRGs) for Contaminated Land Management.

Waste Management

6.2.4 The Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal of wastes. Construction waste is defined as any substance, matter or thing that is generated from construction work and abandoned, whether or not it has been processed or stockpiled before being abandoned, but does not include any sludge, screenings or matter removed in or generated from any desludging, desilting or dredging works. Under the WDO, wastes can be disposed of only at designated waste disposal facilities.

6.2.5 Under the WDO, the Chemical Waste (General) Regulation 1992 provides regulations for chemical waste control, and administers the possession, storage, collection, transport and disposal of chemical wastes. EPD has also issued a guideline document, the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992), which details how the contractor should comply with the regulations on chemical wastes.

6.2.6 Public Cleansing and Prevention of Nuisance Regulation provides control on illegal tipping of wastes on unauthorised (unlicensed) sites.

6.2.7 The Land (Miscellaneous Provisions) Ordinance provides control on dumping of public fill. The inert portion of construction waste (also called public fill) may be taken to public fill reception facilities which are operated by the Civil Engineering and Development Department (CEDD). The Land (Miscellaneous Provisions) Ordinance requires that dumping licences be obtained by individuals or companies who deliver public fill to public filling areas. The CEDD issues the licences under delegated powers from the Director of Lands.

6.2.8 Under the licence conditions, public fill reception facilities will only accept inert earth, soil, sand, rock, boulder, rubble, brick, tile, concrete, asphalt, masonry or used bentonite. In addition, in accordance with Development Bureau Technical Circular (Works) (TC(W)) No. 6/2010, the Public Fill Committee will advise on the acceptance criteria (e.g. no mixing of construction waste, nominal size of the materials less than 250mm, etc.) for disposal of construction and demolition (C&D) materials at public fill facilities.

Construction and Demolition (C&D) Material

6.2.9 The current policy related to the disposal of C&D materials is documented in the Works Branch TC No. 2/93, ‘Public Dumps’. Inert C&D materials such as soil, rock and concrete etc. could be reused onsite as filling materials or off-site as public fill at public fill reception facilities. The non-inert portion, such as timber, paper etc. namely non-inert C&D materials (i.e. C&D waste) should be reused or recycled as far as possible. Landfill disposal should be considered as the last resort for waste handling.

6.2.10 Under the Waste Disposal (Charges for Disposal of Construction Waste) Regulation, enacted in January 2006, construction waste delivered to a landfill for disposal must not contain more than 50% by weight of inert material. Construction waste delivered to a sorting facility for disposal must contain more than 50% by weight of inert material, and construction waste delivered to a public fill reception facility for disposal must consist entirely of inert materials.

6.2.11 The ETWB TC(W) No. 19/2005 “Environmental Management on Construction Sites” includes procedures on waste management requiring contractors to reduce the C&D materials to be disposed of during the course of construction. The ETWB TC(W) No. 33/2002, “Management of Construction and Demolition Material Including Rock” to enhance the management of C&D materials, and to minimize its generation at source, submission of C&D Material Management Plan (C&DMMP) is not required for less than 50,000 m³ C&D materials from Designated Projects and less than 300,000 m³ from non-Designated Projects. Under ETWB TC(W) No. 19/2005, the contractor is required to prepare and implement an Environmental Management Plan (EMP) and the Waste Management Plan becomes part of the EMP.

Chemical Waste

6.2.12 Under the Waste Disposal (Chemical Waste) (General) Regulations, all producers of chemical waste must register with EPD and treat their wastes, either utilising on-site plant licensed by EPD, or arranging for a licensed collector to transport the wastes to a licensed facility. The regulation also prescribes the storage facilities to be provided on site, including labelling and warning signs, and requires the preparation of written procedures and training to deal with emergencies such as spillages, leakages or accidents arising from the storage of chemical wastes.

Marine Sediment

6.2.13 ETWB TC(W) No. 34/2002 Management of Dredged / Excavated Sediment stipulates that marine sediment shall be disposed of at designated dumping ground in accordance to its contamination level. The contamination level of the sediment is classified into three categories (Cat. L, M, H) based on the Chemical Exceedance Levels (CEL) shown in Table 6.1, which determines the disposal method.

Table 6.1: Sediment Quality Criteria for the Classification of Sediment

Contaminants	Lower Chemical Exceedance Level (LCEL)	Upper Chemical Exceedance Level (UCEL)
*Heavy Metal(mg/kg dry weight)*
Cadmium(Cd)	1.5	4
Chromium(Cr)	80	160
Copper(Cu)	65	110
Mercury(Hg)	0.5	1
Nickel(Ni)	40	40
Lead(Pb)	75	110
· Silver(Ag)	1	2
· Zinc(Zn)	200	270
*Metalloid(mg/kg dry weight)*
Arsenic	12	42
*Organic-PAHs(µg/kg dry weight)*
· PAHs(Low Molecular Weight)	550	3160
· PAHs(High Molecular Weight)	1700	9600
*Organic-non-PAHs(µg/kg dry weight)*
Total PCBs	23	180
*Organometallics(µg-TBT L-1 in interstitial water)*
Tributyltin*	0.15	0.15

* The contaminant level is considered to have exceeded the UCEL if it is greater than the value shown.

Category L:	Sediment with all contaminant levels not exceeding the LCEL. The material must be dredged, transported and disposed of in a manner which minimizes the loss of contaminants either into solution or by resuspension.
Category M:	Sediment with any one or more contaminant levels exceeding the LCEL and none exceeding the UCEL. The material must be dredged and transported with care, and must be effectively isolated from the environment upon final disposal unless appropriate biological tests demonstrate that the material will not adversely affect the marine environment.
Category H:	Sediment with any one or more contaminant levels exceeding the UCEL. The material must be dredged and transported with great care, and must be effectively isolated from the environment upon final disposal.

6.3 Assessment Methodology

6.3.1 The assessment of potential waste management implications includes the following tasks in accordance with Annexes 7 and 15 of the EIAO-TM and EIA-SB:

· Estimation of the types and quantities of waste arising by reviewing the construction work activities;

· Evaluation of potential impacts from the handling, collection, transportation and disposal of waste; and

· Proposal of mitigation measures for the waste management.

6.3.2 Land contamination assessment shall include the following tasks:

· Identify any potentially contaminating activities at the site by reviewing historical and present land uses; site visit; and identify any accidents, fires, explosions, spillage and any pollution incidents at the site by reviewing records from Environmental Protection Department (EPD) and Fire Services Department (FSD)

· Review contamination potential

· Submit Contamination Assessment Plan for approval from EPD

· Analyse sampling and testing results and evaluate the impact

· Prepare Contamination Assessment Report and/or Remediation Action Plan for approval from EPD

· If necessary, carry out soil treatment and submit a Remediation Report (RR) to EPD for approval prior to the construction works

6.4 Estimation of Construction Waste Generation and Evaluation of Impact

6.4.1 Waste minimization is of top priority. The amount of waste has been minimized by designing the bridges with minimum land requirement and adopting suitable construction method summarized as follows:

· Adopt minipiling instead of traditional bored piling to minimize the excavation extent.

· Minimize amount of dredging by cutting the existing pier down to 300mm below riverbed. The existing pile cap and the piles will be retained so that no extensive excavation work is needed.

· Similarly, about 300 mm thick of the existing abutments will be demolished while the lower parts of the abutments will be retained as seawalls.

· The foundation for the end support of the pedestrian bridge will be constructed immediately behind the existing seawall.

· Construction of pedestrian bridge, cycle bridge and demolition of Old Bridge will be carried out in phases to minimize the amount of C&D materials generated at one time.

· Excavated materials will be backfilled onsite as far as possible.

6.4.2 The actual amount of waste generated will be dependent on the practice of the Contractor. The preliminary estimate will be given below.

6.4.3 Referring to the detailed construction method in Chapter 2, major construction waste will be:

· Construction and demolition materials

· Marine sediment

· Chemicals waste

· General refuse from workforce

Construction and Demolition Materials (C&D Materials)

6.4.4 C&D materials can be divided into two categories: (1) inert C&D materials, which are suitable for reuse in construction works and (2) non-inert C&D materials, those have to be either recycled, reused offsite or disposed of.

6.4.5 On average, the expected daily production of inert C&D materials is 2.47 m³. Over the whole construction phase, 1,069 m³ would be generated, which will comprise of the following:

· Excavated materials from demolition and construction of mini-piles, pile cap, abutment and pier;

· Broken concrete and metal bars from demolition of the Old Bridge (e.g. deck, abutment, pier & pile cap), modification works on seawall, slope and drainage works, retaining wall etc.; and

· Unused building materials, e.g. concrete.

6.4.6 About 82m³ of non-inert C&D materials will be produced comprising the following:

· Plant materials from tree felling;

· Metal and timber formwork;

· Bamboo scaffolding; and

· Material packaging, e.g. plastic, paper wraps.

6.4.7 Designated area shall be provided for onsite stockpiling and sorting of C&D materials as far as possible, tentatively at the northeastern part of the hoarding area to the north. Sorted inert materials shall be sent to public fill reception facility for beneficial reuse, with the closest one in Mui Wo Temporary Public Fill Reception Facility.

6.4.8 Metal, paper and plastic should be recycled or reused as far as possible. Timber and dismantled bamboo scaffolding should be reused in other projects if the quality remains satisfactory. Other non-inert C&D materials should be disposed of at landfill, with the closest one in West New Territories (WENT) Landfill in Tuen Mun. The contractor shall enquire with the Environmental Protection Department on the availability of landfill and acceptability of the waste.

6.4.9 All waste shall be removed from the Site to public fill reception/sorting facility or landfill by land transport. No barging point or conveyor system will be involved. Given the small quantity of waste generated, one to two truck trips will be sufficient to handle the waste every day. Therefore, no significant air emission, noise nuisance or obstruction on public transport are expected from the limited transport trips.

Marine Sediment

6.4.10 Excavation below high water mark may be considered as dredging work. This will be required for two main purposes: (1) demolition of one of the existing piers down to 300mm below riverbed and (2) piling for construction of new piers. Excavation works will be conducted within enclosed cofferdams.

6.4.11 For (1), the disturbed materials (in the surface layer of Wang Tong River) will be sand and gravels based on site visits during the EIA study (see Appendix 6B for site photos). For (2), soil will be excavated down to 1m below the proposed pile cap (about 2m below ground level for the deepest pile cap). After that minipiles will be inserted into the ground. According to the ground investigation (GI) conducted next to the abutments of Old Bridge in 2013, the soil within 4m depth from the surface belonged to beach sand. Alluvium (comprising sand, clay, silt and cobble), saprolite (comprising sandy clayey silt or silty sand with gravel) and rock (comprising moderately and slightly decomposed granite) will be encountered further underground (see Appendix 6D for extracts of GI report). One of the new pedestrian bridge piers will be constructed at the same location of the other Old Bridge pier. Demolition of existing pile cap will also be required, which will be within 4m below surface. Therefore, beach sand be excavated and no sediment will be generated during excavation works.

6.4.12 Marine sediment will be encountered for works deep underground, i.e. piling works. About 87m³ of sediment will be extracted from minipiles. These will be treated by cement solidification and sent to laboratory for Toxicity Characteristics Leaching Procedure (TCLP) test according to USEPA Method 1311 and 6020. The results are considered satisfactory if Universal Treatment Standards (UTS) are being met as per Table 4.6 of Practice Guide of Investigation and Remediation of Contaminated Land. The Unconfined Compressive Strength (UCS) of the solidified sediment shall also reach 1000kPa according to the above Practice Guide. If the TCLP and UCS testing results cannot meet the criteria, the sediment shall be retreated by cement solidification. After passing the tests, the solidified sediment shall be backfilled on land after the piling work (e.g. for construction of new piers and abutments). Alternatively, the solidified sediment shall be delivered to public fill reception facilities for beneficial reuse as the last resort. No disposal at sea is required.

Chemical Wastes

6.4.13 Chemical wastes that may arise during the construction of the Project include:

· Paint, solvents and detergents in fabricating the New Bridge;

· Cleansing fluid, lubricating oil, scrap batteries and fuel in maintaining and powering machinery; and

· Empty containers of the above substances.

6.4.14 The amount of chemical wastes generated will vary between Contractors based on the number of plant equipment to be employed and the maintenance frequency. However, it is expected to be limited (about 1m³) due to the small project scale.

6.4.15 Improper handling of the chemical wastes may pose health impact on workers (e.g. accidental ingestion), fire hazard and contamination of soil and water. The Contractor shall register with EPD as a chemical waste producer. All chemical wastes will be delivered to Chemical Waste Treatment Centre in Tsing Yi for treatment and disposal in strict compliance with the Waste Disposal (Chemical Waste) (General) Regulations.

General Refuse

6.4.16 General refuse refers to the waste generated by workers during daily operation, e.g. food waste and packaging, metal cans, plastic bottles and office waste. The estimated daily generation is about 0.0185 m³ and the total quantity for this project is about 8 m³.

6.4.17 Even though the quantity is small, sufficient rubbish bins or collection area should still be provided to maintain the hygiene and tidiness of the work site. Otherwise the waste may be blown away by wind or washed into Wang Tong River or Silvermine Bay. In addition to causing pollution problem, this may clog drainage system, resulting in flooding under heavy rain. Having rubbish around is also unpleasant and may attract pest and bring odour nuisance. The bins should always be covered by lids. Recycle bins should also be provided to encourage recycling paper, metal and plastic. The collected waste shall be removed at regular interval. No dropping of refuse into water that result in water pollution or accumulation is expected.

6.4.18 The proposed New Bridge will have piers above high water mark and the abutment will be either above high water mark or follow the original design of the Old Bridge. No additional trapping of floating refuse is expected during operational phase.

Other Wastes (Human Waste)

6.4.19 There is a public toilet in Silver Mine Bay Beach which the workers can use. Chemical toilets should be provided if necessary, which should be maintained regularly by registered waste collectors. They should be placed on stable, impermeable ground and kept away from the river bank and shore.

6.4.20 With proper implementation of mitigation measures in Section 6.7, no unacceptable waste management impact due to handling, collection, transportation and disposal of C&D materials, chemical wastes, marine sediment (if any) and general refuse is expected.

Table 6.2: Summary of Waste

Type of Waste		Quantity (m³)				Handling and Disposal Options
Type of Waste		Onsite Reuse	Offsite Reuse (Public Fill)	Dispose (Landfill)	Total	Handling and Disposal Options
1	Inert C&D Material	403	666	0	1069	To be reused on-site for backfilling. Those cannot be reused on-site will be delivered to Mui Wo Temporary Public Fill Reception Facility.
	Site Clearance and Formation (inc. the demolition of Old Bridge)	203	100	0	303
	Pile Cap, Pier & Abutment Construction	200	100	0	300
	Superstructure construction & Finishes (inc. associated works e.g. drainage works)	0	466	0	466
		0	466	0	466
2	Non-inert C&D Material	0	0	82	82	To be disposed of at landfill (the closest landfill is West New Territories Landfill)
	Site Clearance and Formation (inc. the demolition of Old Bridge)	0	0	23	23
	Pile Cap, Pier & Abutment Construction	0	0	23	23
	Superstructure construction & Finishes (inc. associated works e.g. drainage works)	0	0	36	36
		0	0	36	36

Type of Waste		Quantity (m³)			Handling and Disposal Options
Type of Waste		Reuse/ Recycle	Dispose	Total	Handling and Disposal Options
3	Sediment extracted from Minipiles	87	0	87	To be reused on-site for backfilling on land or delivered to public fill reception facilities for beneficial reuse after cement solidification
4	Chemical Waste	0	1	1	To be disposed to Chemical Waste Treatment Centre
5	General Refuse	7	1	8	To be disposed of at landfill

6.5 Land Contamination

Historical Land Uses

6.5.1 Historical aerial photographs covering the Study Area were reviewed to evaluate any land use changes associated with potential contamination implication within the assessment area. The oldest aerial photo available dated back to 1945. Changes of land use observed are shown in the following table:

Table 6.3: Historical Change in Wang Tong River and its vicinity

Year	Photo No.	Descriptions
1945	3079	- Very extensive agricultural land in Wang Tong, Tai Wai Yuen and land to the west of Butterfly Hill - Old bridges at mouth of River Silver & Wang Tong River - Both Wang Tong River and River Silver were untrained and had large mudflat at river mouth
1970	N/A	- Opening of bridge across Wang Tong River (Old Bridge of this project) according to the commemorative tablet of the bridge
1973	4026	- Shape of Wang Tong River as now - Houses built at Tung Wan Tau Road near Wang Tong River and along Wang Tong River at the foot of Butterfly Hill
1976	14915	- Road constructed along Silvermine Bay Beach - Structure at the now Silvermine Beach Resort demolished
1978	22450	- More houses in Tung Wan Tau along Silvermine Bay Beach
1982	41929	- Construction of Silvermine Beach Resort (South Wing) - Houses started to build in Wang Tong - Reclamation of River Silver
1984	57313	- River Silver (Southern Side) as now - Construction of swimming pool in Silvermine Beach Resort
1986	A07830	- Channelization of River Silver completed
1988	A12490	- Development of land to the north of River Silver
1991	A29129	- More houses built in Wang Tong - Development of Silvermine Beach Resort (North Wing)
1992	CN03019	- Layout within 500m Study Area similar to now
1996	942353	- Channelization of upper reach of Wang Tong River in progress
2003	CN51918	- 7-shaped water channel observed in Tai Wai Yuen
2010	CS30503	- Barge berthed in waters in front of Silvermine Beach Resort, area of beach between front of Silvermine Beach Resort and Wang Tong River reduced
2011	CS33663	- Beach mentioned above was reinstated
2014	CS51073	- Clearing of trees along Wang Tong River at the foot of Butterfly Hill

6.5.2 Based on the aerial photos, area near Wang Tong River was historically used for residential (village) and agriculture. Population started to expand from 1970s as evident from conversion of agriculture land into houses. Construction of Silvermine Beach Resort in 1980s showed the growth of tourism in Mui Wo. Major reclamation took place in River Silver over 100m away to the south of the Site. No industrial activity was identified. Aerial photos showing major changes are shown in Appendix 6A.

Current Land Uses

6.5.3 Site visits were carried out during the EIA study period to identify the latest land use. There are village houses to the north of the Old Bridge, along upper reach of Wang Tong River and Mui Wo Committee Road. Some of the village houses are rented as resort. A hotel (Silver Beach Resort) is located to the south of the Old Bridge. Majority of the agriculture land in Tai Wai Yuen and Wang Tong have already been abandoned. Only small scale farming was practised at the door front of some of the village houses. Silvermine Bay Beach is a popular bathing beach and clam digging site. There is a restaurant to the north of the Old Bridge that has long been closed. In general, area within the Site Boundary did not experience major landscape alternation since the 1990s. Photographic records of existing land uses are shown in Appendix 6B.

Chemical Waste, Dangerous Goods and Spillage Records

6.5.4 No land contamination report was found in Mui Wo. Enquiry has been sought from EPD on any historic record on chemical waste spillage/leakage incidences in the vicinity of the Project Site, and from FSD on dangerous goods licence and spillage/leakage of dangerous of goods. Both departments confirmed neither records were found (letter attached in Appendix 6C). No chemical waste producer record was found within the Project boundary in the EPD’s Register.

Potential Land Contamination Impact

6.5.5 According to Guidance Note for Contaminated Land Assessment and Remediation and EIAO-TM Annex 19, the following industrial uses may result in land contamination:

· oil installations including oil depots and petrol filling stations

· gas works

· power plants

· shipyards/boatyards

· chemical manufacturing/processing plants

· steel mills/metal workshops

· car repairing and dismantling workshops

· dumping ground and landfill

· scrap yards

6.5.6 Construction of village houses and operation of restaurant to the north of Old Bridge, and conversion of agriculture land to village houses along Wang Tong River in the vicinity of the Site did not constitute land contamination potential. Therefore, no land contamination potential is expected in the northern bound of the Old Bridge.

6.5.7 There was a red-roofed, three parted structure at the now Silvermine Beach Resort (South Wing) between 1945 and 1976, which may possibly be a pig farm. There may be land contamination if chemical pig feed was being used. However, any contaminated soil in the area should have been excavated during construction of Silvermine Beach Resort and road surrounding the resort and associated utility in these decades. Also, there is also about 50m buffer distance from the location of potential contamination hotspot (Pig Farm/now Resort). The potential of land contamination impact during excavation work of this Project is low.

6.5.8 Based on the site appraisal, aerial photos and site visits showed that no industrial activity listed under the Guidance Notes or EIAO-TM (see Section 6.5.5) was conducted in the vicinity of Wang Tong Bridge. Records from EPD and FSD confirmed that there was no chemical waste producer, dangerous goods store nor chemical spillage record at the Project Site and in the vicinity of the site. As no land contamination within the Project Site is expected, no soil sampling, testing and analysis is required. No potential hazard is expected due to handling, collection, transportation and re-use/disposal of excavated soil is anticipated.

6.5.9 Should contaminated soil be found during the excavation work, the process should be terminated. Contamination Assessment Plan (CAP) shall be prepared in accordance with EPD’s Guidance Note for Contaminated Land Assessment and Remediation for identifying soil and groundwater sampling locations, followed by testing and remediation where necessary.

6.6 Estimation of Operational Waste Generation and Evaluation of Impact

6.6.1 During operational phase, no significant impact is expected due to operation of the Project.

6.7 Mitigation Measures

6.7.1 The Contractor should prepare a Waste Management Plan in accordance with ETWB TCW No. 19/2005 Waste Management on Construction Site, which details the expected amount of different types of wastes generated in the coming month and year and updates at regular intervals. The actual waste usage should be recorded monthly. Waste handling, storage and removal methods should also be proposed in the WMP and be reviewed the effectiveness at regular intervals. Training should be provided to all staff to ensure that they are aware of the practice, in particular in chemical waste handling (e.g. understanding of hazard labels and emergency procedures).

6.7.2 Careful planning before construction work and close monitoring will be crucial to prevent performing unnecessary works, resulting in extra waste.

C&D Waste

6.7.3 Handling, storage, collection and disposal of waste shall be proposed in accordance with Waste Disposal Ordinance. Good site practices shall be implemented to minimize undesirable nuisance:

· The Contractor shall identify suitable location for temporary stockpiling, tentatively on the northeastern part of the Project Boundary inside hoarding. The stockpile should be covered by tarpaulin or other water-resistant fabric. This can prevent the waste from being blown away by wind or washed into watercourses/sea/drainage system under heavy rain. No water pollution of watercourse and thus impact on ecology is expected.

· Waste sorting area should be provided as far as possible to separate out reusable, recyclable wastes and/or public fill. Dumping at landfill should be considered as last resort.

· Sorted waste should be stored separately at designated locations.

· If there is insufficient space for stockpiling the waste onsite before disposal offsite, the waste materials should be delivered offsite for storage/sorting or disposal upon generation.

· Dump trucks should be near fully loaded with excavated materials before departure from the Site. Frequent movement of traffic will be a source of annoyance and increase the chance of accidental leakage.

· However, the trucks should not be overloaded and the cover should be closed to enclose the excavated materials during movement.

· Adopt durable materials for formworks and scaffolding (e.g. steel) for future reuse.

· Works schedule will be well planned to minimize the excavation work area in any time.

Chemical Waste

· Chemical wastes should be stored at designated chemical waste storage area with bunds on impermeable ground. Roof and locks should be provided if stored outdoor. Alternatively, cabinet or cupboard with spill trays can be used if the quantity of waste is small.

· Chemical wastes should be labelled clearly in accordance with Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes to alert workers on hazard during handling and storing.

· Compatible containers should be used for storing specific chemical waste to prevent leakage/spillage (e.g. resistant to corrosive chemicals). Checking of the integrity of the containers before and during use is required.

· The Contractor should be registered as a Chemical Waste Producer with EPD and engage licensed chemical waste collectors for disposal under the Waste Disposal (Chemical Waste)(General) Regulation.

General

· Sufficient rubbish bins should be provided at regular interval for collection of general refuse.

· Recycle bins should be provided to encourage recycling of paper, plastic and metal cans.

· Collected waste should be removed from the site by registered collectors regularly.

· A trip ticket system should be implemented to monitor the flow of waste from the site to public fill reception facilities/landfill/chemical waste treatment facilities/recycler.

Marine Sediment

6.7.4 Marine sediment shall be treated by cement solidification and reused onsite by backfilling on land. Alternatively, the solidified sediment shall be delivered to public fill reception facilities for beneficial reuse as the last resort.

Land Contamination

6.7.5 Although no land contaminated site is identified, precautionary measures shall be carried out. In addition to proper waste management measures listed above, preventive measures are recommended to workers to minimize the chance of contact:

· Use plant equipment to perform excavation as far as possible;

· Wear protective glove and face mask during excavation work; and

· Prohibit eating and smoking.

6.8 Residual Impact

6.8.1 With proper implementation of the mitigation measures, no residual impact is anticipated for waste generated from construction and operation of the Project.

6.9 Environmental Monitoring and Audit

6.9.1 The Contractor should prepare a Waste Management Plan in accordance with ETWB TCW No. 19/2005 Waste Management on Construction Site, which details the expected amount of different types of wastes generated in the coming month and year and updates at regular intervals. The actual waste usage should be recorded monthly. Waste handling, storage and removal methods should also be proposed in the WMP and be reviewed the effectiveness at regular intervals. Training should be provided to all staff to ensure that they are aware of the practice, in particular in chemical waste handling (e.g. understanding of hazard labels and emergency procedures).

6.9.2 Regular site inspection shall be carried out during construction phase to check whether the proposed mitigation measures have been properly implemented and to evaluate the effectiveness.

6.9.3 No EM&A is proposed for Operational Phase.

6.10 Conclusion

6.10.1 During construction phase, major C&D waste will be composed of broken concrete, metal bar, sand and soil from demolition of Old Bridge. Other waste includes chemical waste from maintenance of plant equipment, general refuse from workforce, and marine sediment extracted from minipiles.

6.10.2 No waste generation activity is expected in operational phase.

6.10.3 The waste shall be handled and disposed of properly to prevent causing damage to the environment, e.g. water pollution, odour nuisance and hygiene issue. With implementation of the recommended measures and site practices, no unacceptable impact due to waste management is expected.

6.10.4 Based on historical aerial photos, site visit and government record, it is concluded that land contamination at the Site is unlikely.

7. Ecological Impact

7.1 Introduction

7.1.1 This chapter presents the ecological baseline condition within and in the vicinity of Wang Tong through literature review and surveys. Potential construction and operational impacts on ecology caused by this Project have been identified and evaluated. Mitigation measures have been proposed to minimize potential impacts where necessary.

7.2 Relevant Legislations, Standards & Guidelines

7.2.1 Reference has been made to the Technical Memorandum on Environmental Impact Assessment Process of the Environmental Impact Assessment Ordinance (Cap. 499) (EIAO-TM) for the criteria for evaluating ecological impacts, i.e.:

· Annex 8 stipulates criteria for evaluating ecological impacts

· Annex 16 sets out the general approach and methodology for the assessment of ecological impacts arising from a project or proposal.

7.2.2 The following EIAO guidance notes detail temporal considerations in arranging surveys, survey methodology at different habitat types, data collection and requirement of impact assessment:

· GN 6/2010 “Some Observations on Ecological Assessment from the Environmental Impact Assessment Ordinance Perspective”

· GN 7/2010 “Ecological Baseline Survey for Ecological Assessment”

· GN 10/2010 “Methodologies for Terrestrial and Freshwater Ecological Baseline Surveys”

7.2.3 Other Hong Kong ordinances and guidelines relevant to this study for reference include:

· Forests and Countryside Ordinance (Cap. 96) and its subsidiary legislation in the Forestry Regulations, which prohibit destructive activities in the forest and trading or keeping of rare plants;

· Wild Animals Protection Ordinance (Cap. 170), which protects wild mammals, avifauna, reptiles, amphibians and insects under column 2 from hunting, possession, trading and disturbance;

· Country Parks Ordinance (Cap. 208), which designates, controls and manages country parks and special areas;

· Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586), which regulates trading and possession of endangered species in response to Convention on the International Trade in Endangered Species of Wild Fauna and Flora (CITES);

· Town Planning Ordinance (Cap. 131), which stipulates the planning use of an area. Land uses related to this chapter are country parks, conservation areas, green belts, coastal protection areas, sites of special scientific interest and other specified uses that promote conservation or protection of the environment;

· Hong Kong Planning Standard and Guidelines (Chapter 10), which provides principles of conservation, policies to identify and conserve natural landscape and habitats through legislation and administrative controls and planning.

7.2.4 In addition, legislations, standards and guidelines in People’s Republic of China (PRC) relevant to this assessment include:

· PRC Wild Animal Protection Law;

· List of State Protected Wild Animals;

· List of Wild Plants;

· China Red Data Book of Endangered Animals;

· China Plant Red Data Book; and

· China Species Red List

7.2.5 This assessment was also referenced to the following international conventions where appropriate:

· Convention on the International Trade in Endangered Species of Wild Fauna and Flora (CITES);

· IUCN Red List;

· United Nations Conventions on Biological Diversity (1992).

7.3 Study Area & Ecological Sensitive Receivers

7.3.1 The Study Area for terrestrial and aquatic ecological impact assessment covered 500m radius of the Project, as shown in Figure 7.1. The assessment area included Silver Mine Bay, Wang Tong River, Tai Wai Yuen and other areas that are possibly impacted by the Project. No recognized site of conservation importance as defined in Annex 16 of the EIAO-TM was identified within the Study Area.

7.3.2 Ecological impact assessment was carried out according to criteria and guidelines as stated in Annexes 8 and 16 of the EIAO-TM, and was followed the technical requirements given in Appendix E of the Study Brief (No. ESR-246/2013).

7.4 Literature Review

7.4.1 Baseline ecological information had been obtained through collection and review of past findings in relevant studies/surveys regarding the ecological characters of the assessment area. Examples of published reference and other environmental studies carried out in vicinity of the Project site include:

· Aerial photos

· Websites managed by AFCD, e.g. Hong Kong Biodiversity Database & Hong Kong Herbarium

· AFCD Newsletters

· Approved Mui Wo Fringe OZP S/I-MWF/10 from Town Planning Board

· Books and reports by Hong Kong Bird Watching Society, e.g. the Avifauna in Hong Kong

· Memoirs of Hong Kong

· Past EIA studies, e.g. Drainage Improvements in Southern Lantau

· Porcupine! by the University of Hong Kong

· Rare and Precious Plants of Hong Kong

· China Red Data Book (Aves and Pisces)

· Other related field books

Vegetation

7.4.2 According to M&EL (2005), 2 plant species with conservation importance, Aquilaria sinensis and Diospyros vaccinioides, were recorded in secondary woodland around the Butterfly Hill. Their locations were about 500m northwest from the Project Site, while their conservation statuses were summarized in Table 7.1.

Table 7.1: Plant species of conservation importance recorded in past studies within/near the Study Area (Hu et al. 2003; IUCN 2014)

Species Name (Chinese Name)	Origin	Conservation Status
Aquilaria sinensis (土沉香)	Native	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) 2. Listed as “Near Threatened” in Rare and Precious Plants of Hong Kong 3. Listed as “Vulnerable” in China Plant Red Data Book 4. Listed as “Vulnerable” by the IUCN Red List
Diospyros vaccinioides (小果柿)	Native	1. Listed as “Critically Endangered” by the IUCN Red List

Species Name
(Chinese Name)

Origin

Conservation Status

Aquilaria sinensis

(土沉香)

Native

1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586)

2. Listed as “Near Threatened” in Rare and Precious Plants of Hong Kong

3. Listed as “Vulnerable” in China Plant Red Data Book

4. Listed as “Vulnerable” by the IUCN Red List

Diospyros vaccinioides

(小果柿)

Native

1. Listed as “Critically Endangered” by the IUCN Red List

Terrestrial Mammals

7.4.3 According to Shek (2006), Domestic Ox (Bos taurus) and 10 bat species were recorded around the Study Area. Except the Short-nosed Fruit Bat (Cynopterus sphinx), all of the 9 bat species tend to roost in cave (i.e. the abandoned Silver Mine Cave which is more than 900 m away from the Project Site). Both Domestic Ox and Short-nosed Fruit Bat are common and widely distributed in Hong Kong (AFCD 2014). Domestic Ox has no conservation status while the Short-nosed Fruit Bat is protected under the Wild Animals Protection Ordinance (Cap. 170).

Avifauna

7.4.4 In Hong Kong, all wild birds are protected under the Wild Animals Protection Ordinance (Cap. 170).

7.4.5 According to M&EL (2005), 8 avifauna species with conservation importance – Great Egret (Ardea alba), Grey Heron (Ardea cinerea), Chinese Pond Heron (Ardeola bacchus), Eastern Cattle Egret (Bubulcus coromandus), Striated Heron (Butorides striata), Little Egret (Egretta garzetta), White-throated Kingfisher (Halcyon smyrnensis) and Black-crowned Night Heron (Nycticorax nycticorax) – were found within/near the Study Area. The closest record was near River Silver, which is about 500 m away from the Project Site. Their conservation statuses were summarized in Table 7.2.

7.4.6 According to a breeding bird survey conducted by the Hong Kong Bird Watching Society in 1993 – 1996 (Carey et al. 2001), 36 bird species were recorded to breed within/around the Study Area. Except 7 species are uncommon/scarce and/or having limited distribution, all of them are common and widespread in Hong Kong (AFCD 2014). 11 of the 36 species – Bonelli's Eagle (Aquila fasciata), Striated Heron (Butorides striata), Greater Coucal (Centropus sinensis), Little Egret (Egretta garzetta), Slaty-breasted Rail (Gallirallus striatus), White-throated Kingfisher (Halcyon smyrnensis), White-bellied Sea Eagle (Haliaeetus leucogaster), Cinnamon Bittern (Ixobrychus cinnamomeus), Black-crowned Night Heron (Nycticorax nycticorax), Collared Scops Owl (Otus lettia) and White-shouldered Starling (Sturnia sinensis) – are species with conservation importance. Their conservation statuses were summarized in Table 7.2.

Table 7.2: Avifauna species of conservation importance recorded in past studies within/near the Study Area (Zheng & Wang 1998; Carey et al. 2001; Fellowes et al. 2002; M&EL 2005)

Common Name (Species Name)	Conservation Status
Bonelli's Eagle (Aquila fasciata)	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586); 2. Listed as “Rare” in China Red Data Book Status (Zheng & Wang 1998); 3. Listed as “Regional Concern” by Fellowes et al. (2002)
Great Egret (Ardea alba)	1. Listed as “Regional Concern” by Fellowes et al. (2002)
Grey Heron (Ardea cinerea)	1. Listed as “Potential Regional Concern” by Fellowes et al. (2002)
Chinese Pond Heron (Ardeola bacchus)	1. Listed as “Regional Concern” by Fellowes et al. (2002)
Eastern Cattle Egret (Bubulcus coromandus)	1. Listed as “Local Concern” by Fellowes et al. (2002)
Striated Heron (Butorides striata)	1. Listed as “Local Concern” by Fellowes et al. (2002)
Greater Coucal (Centropus sinensis)	1. Listed as “Vulnerable” in China Red Data Book Status (Zheng & Wang 1998)
Little Egret (Egretta garzetta)	1. Listed as “Regional Concern” by Fellowes et al. (2002)
Slaty-breasted Rail (Gallirallus striatus)	1. Listed as “Rare” in China Red Data Book Status (Zheng & Wang 1998); 2. Listed as “Regional Concern” by Fellowes et al. (2002)
White-throated Kingfisher (Halcyon smyrnensis)	1. Listed as “Local Concern” by Fellowes et al. (2002)
White-bellied Sea Eagle (Haliaeetus leucogaster)	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586); 2. Listed as “Indeterminate” in China Red Data Book Status; 3. Listed as “Regional Concern” by Fellowes et al. (2002)
Cinnamon Bittern (Ixobrychus cinnamomeus)	1. Listed as “Local Concern” by Fellowes et al. (2002)
Black-crowned Night Heron (Nycticorax nycticorax)	1. Listed as “Local Concern” by Fellowes et al. (2002)
Collared Scops Owl (Otus lettia)	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586)
White-shouldered Starling (Sturnia sinensis)	1. Listed as “Local Concern” by Fellowes et al. (2002)
All birds are protected under the Wild Animals Protection Ordinance (Cap. 170). * Species listed as “Least Concern” by IUCN Red List were not included

Common Name

(Species Name)

Conservation Status

Bonelli's Eagle

(Aquila fasciata)

1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586);

2. Listed as “Rare” in China Red Data Book Status (Zheng & Wang 1998);

3. Listed as “Regional Concern” by Fellowes et al. (2002)

Great Egret

(Ardea alba)

1. Listed as “Regional Concern” by Fellowes et al. (2002)

Grey Heron

(Ardea cinerea)

1. Listed as “Potential Regional Concern” by Fellowes et al. (2002)

Chinese Pond Heron

(Ardeola bacchus)

1. Listed as “Regional Concern” by Fellowes et al. (2002)

Eastern Cattle Egret

(Bubulcus coromandus)

1. Listed as “Local Concern” by Fellowes et al. (2002)

Striated Heron

(Butorides striata)

1. Listed as “Local Concern” by Fellowes et al. (2002)

Greater Coucal

(Centropus sinensis)

1. Listed as “Vulnerable” in China Red Data Book Status (Zheng & Wang 1998)

Little Egret

(Egretta garzetta)

1. Listed as “Regional Concern” by Fellowes et al. (2002)

Slaty-breasted Rail

(Gallirallus striatus)

1. Listed as “Rare” in China Red Data Book Status (Zheng & Wang 1998);

2. Listed as “Regional Concern” by Fellowes et al. (2002)

White-throated Kingfisher

(Halcyon smyrnensis)

1. Listed as “Local Concern” by Fellowes et al. (2002)

White-bellied Sea Eagle

(Haliaeetus leucogaster)

1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586);

2. Listed as “Indeterminate” in China Red Data Book Status;

3. Listed as “Regional Concern” by Fellowes et al. (2002)

Cinnamon Bittern

(Ixobrychus cinnamomeus)

1. Listed as “Local Concern” by Fellowes et al. (2002)

Black-crowned Night Heron

(Nycticorax nycticorax)

1. Listed as “Local Concern” by Fellowes et al. (2002)

Collared Scops Owl

(Otus lettia)

1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586)

White-shouldered Starling

(Sturnia sinensis)

1. Listed as “Local Concern” by Fellowes et al. (2002)

*All birds are protected under the Wild Animals Protection Ordinance (Cap. 170).

** Species listed as “Least Concern” by IUCN Red List were not included

7.4.7 Despite the breeding bird survey conducted by the Hong Kong Bird Watching Society (Carey et al. 2001) in 1993 – 1996 recorded breeding White-bellied Sea Eagle (Haliaeetus leucogaster) within/around the Study Area, a breeding White-bellied Sea Eagle survey carried out by Agriculture, Fisheries and Conservation Department (So & Lee 2011) from 2002/03 to 2008/09 recorded that no bird nest was close to the Study Area. The nearest nests were in Shek Kwu Chau and Penny’s Bay, which were about 8 km far away from the Study Area.

Herpetofauna

7.4.8 According to Lau & Dudgeon (1999) and Chan et al. (2005), a total of 11 amphibian species (including Asian Common Toad Duttaphrynus melanostictus, Brown Tree Frog Polypedates megacephalus and Gunther's Frog Rana guentheri) were recorded in/near the Study Area. Three species – Chinese Bullfrog (Hoplobatrachus rugulosus), Three-striped Grass Frog (Hylarana macrodactyla) and Romer's Tree Frog (Liuixalus romeri) – have restricted distribution in Hong Kong, while three species – Chinese Bullfrog (Hoplobatrachus rugulosus), Romer's Tree Frog (Liuixalus romeri) and Short-legged Toad (Xenophrys brachykolos) – are listed as having conservation importance. Their distribution in Hong Kong and conservation status were presented in Table 7.3.

Table 7.3: Amphibian species of conservation importance recorded in past study in/near the Study Area and their distributions in Hong Kong (Fellowes et al. 2002; Chan et al. 2005; AFCD 2014)

Common Name (Species Name)	Distribution in Hong Kong	Conservation Status
Chinese Bullfrog (Hoplobatrachus rugulosus)	Widely distributed in Lantau Island and New Territories	1. Listed as “Potential Regional Concern” by Fellowes et al. (2002)
Three-striped Grass Frog (Hylarana macrodactyla)	Distributed in marshy areas on Lantau Island and New Territories	N.I.L.
Romer's Tree Frog (Liuixalus romeri)	Distributed in woodlands on Lantau Island, Po Toi Island, Lamma Island, Hong Kong Island and New Territories	1. Protected under the Wild Animals Protection Ordinance (Cap. 170) 2. Listed as “Endangered” by the IUCN Red List 3. Listed as “Potential Global Concern” by Fellowes et al. (2002)
Short-legged Toad (Xenophrys brachykolos)	Widely distributed in upland forest streams throughout Hong Kong	1. Listed as “Endangered” by the IUCN Red List 2. Listed as “Potential Global Concern” by Fellowes et al. (2002)

Freshwater Fish

7.4.9 According to M&EL (2005), a total of 19 fish species were recorded in 3 watercourses which all converge into River Silver (about 200m south from Wang Tong River). 10 of the 19 species recorded in tributaries of River Silver are capable of migrating from freshwater to sea (or vice versa), either with or without breeding purpose (e.g. Grey mullet Mugil cephalus, Common mudskipper Periophthalmus modestus and Jarbua terapon Terapon jarbua). Although River Silver and Wang Tong River have no connection, they might also be present in Wang Tong River via the Silver Mine Bay. Among these 10 migratory species, Dark-margined Flagtail Kuhlia marginata is listed as “Regional Concern” by Fellowes et al. (2002). This species is catadromous, which stays entirely in freshwater and migrates downstream to breed.

7.4.10 According to Chong & Dudgeon (1992), a total of 11 fish species were recorded in Mui Wo. 4 of the 11 species that migrate from freshwater to sea (or vice versa) either with or without purpose of breeding recorded in Mui Wo (e.g. Spinecheek Gudgeon Eleotris acanthopoma and Estuarine goby Mugilogobius abei) might also present in Wang Tong River via the Silver Mine Bay. None of the 4 migratory species has conservation status.

Freshwater Invertebrates

7.4.11 According to M&EL (2005), a total of 35 taxa were recorded in 3 watercourses which all converge into the River Silver (about 200m south from Wang Tong River). Estuarine species such as crabs (e.g. Hemigrapsus penicillatus and Varuna litterata) and polychaete worms dominated in downstream, while freshwater insect (e.g. Ephemeroptera and Anisoptera) dominated the upstream. No taxa with conservation importance was recorded.

Marine Mammals

7.4.12 According to Hung (2015), Chinese White Dolphin (Sousa chinensis) mainly concentrates in West coast of Lantau, while Indo-Pacific finless porpoise (Neophocaena phocaenoides) mainly concentrates between Soko Island and Shek Kwu Chau. Their distributions near Lantau Island are presented in Appendix 7E. No marine mammal was recorded at the Eastern Region of Lantau (i.e. near the Study Area). The closest record of both species are about 7 km away from the Study Area (Hung 2015).

7.4.13 Information collected from literature review was evaluated to identify any data gap. Since the literature was only able to provide limited baseline ecological information, detailed ecological surveys were conducted to obtain a comprehensive and updated baseline ecological condition of the Study Area.

7.5 Methodology for Ecological Surveys

7.5.1 Covering both wet and dry seasons, ecological surveys were carried out at representative habitats that are likely to be affected by this Project in June, August to November 2014 and February 2015. Survey plan for systematic surveys (i.e. survey transect, point count locations & sampling point for freshwater communities) is presented in Figure 7.1. Opportunistic observations of wildlife outside systematic survey had also been recorded.

7.5.2 Terrestrial and freshwater surveys had been conducted according to the Environmental Impact Assessment Ordinance, Cap.499, GN No. 10/2010 Methodologies for Terrestrial and Freshwater Ecological Baseline Surveys.

Habitat Survey

7.5.3 Aerial photos of the proposed site and its surrounding had been interpreted to identify types of habitat found within the Study Area. This had been verified and updated by ground-truthing.

Vegetation Survey

7.5.4 Vegetation surveys had been conducted to identify key vegetation communities and dominant species within the proposed site area. These were followed by plant species surveys which recorded plant species found in different habitats within the survey area. A pair of binoculars were used to aid observation where the area is inaccessible. Any rare, protected and threatened plant species and other species of conservation importance had been identified with their location marked.

Terrestrial Mammal Survey

7.5.5 Terrestrial mammals had been actively searched along a designed transect and identified by direct observation. Any traits observed, such as dung, feeding signs, footprints, burrows and dens were recorded, and tracks that were left by mammals were identified as far as possible.

Avifauna Survey

7.5.6 Transect survey and point count had been adopted to record bird species in early morning when they are most active and in night time. For point count, counts had been made within fixed time period (around 5 minutes) using a pair of binoculars. Any birds presented within observable distance along the transect and from the counting point were recorded and identified. Identification was also made from bird calls. In addition, any feeding, nesting and breeding behaviours were noted.

Herpetofauna Survey

7.5.7 Active searching had been carried out to look for amphibians and reptiles along the transect during both day- and night-time. Potential breeding ground and microhabitats, such as pools, water channels, crevices and fallen leaves, had been searched. Any eggs and tadpoles found were also recorded. Mating calls of frogs and toads were assisted in species identification as well.

Butterflies and Odonates Survey

7.5.8 Butterflies and odonates surveys had been conducted during daytime and under fine weather when these insects are active. Transect survey and point count had been carried out. For point count, counts had been made within fixed time period (around 5 minutes). Any butterflies and odonates observed along the transect and from the counting point were counted and identified by naked eyes. A pair of binoculars were used for assisting species identification and counting when necessary.

Freshwater Survey

7.5.9 Bankside counting had been carried out on selected locations. A pair of 8x binoculars had been used to search and observe active swimming fish and crustacean from bankside. Both species and number of fish and crustacean observed had been recorded. Active searching for freshwater fauna with a D-framed hand net had also been carried out.

7.5.10 Trapping had been carried out on selected sampling locations for fish survey. Pot traps of about 0.5-cm and 1-cm mesh size with baits were used. Pots traps had been placed at sampling site for around 20-30 minutes. During this period, disturbance to the water body was avoided. Both species and number of fish trapped had been recorded.

Inter-tidal Survey

7.5.11 Walk-through survey had been carried out at random locations in the inter-tidal zone during low tide. Species found (e.g. crustacean & mollusca) were recorded.

7.5.12 Both general ecological condition and distribution of wildlife in inter-tidal zone can be obtained through walk-through survey. Species were mostly found in low tidal zone (i.e. far from shore). Due to the small project scale, localized project footprint at the existing Wang Tong Bridge and the project site is far away from marine waters, the impact on inter-tidal habitat is expected to be limited. Therefore, no quantitative survey was conducted.

Nomenclature

7.5.13 Nomenclature of species was referenced from the followings:

· Plants were referenced from “Check List of Hong Kong Plants 2012” (Hong Kong Herbarium 2012),

· Terrestrial mammals were referenced from “A Field Guide to the Terrestrial Mammals in Hong Kong” (Shek 2006);

· Avifauna were referenced from “List of HK Birds” (HKBWS 2015);

· Herpetofauna (i.e. amphibian and reptile) were referenced from “Images of Amphibians of Hong Kong” (PE&B HKU 2010) and “Checklist of Reptiles in Hong Kong” (ERCL HKU 2012)

· Butterflies were referenced from “Encyclopaedia of Hong Kong Butterflies – Butterflies Identification (2nd Edition)” (Pun & Yeung 2012)

· Odonates were referenced from “The Dragonflies of Hong Kong” (Tam et al. 2011)

7.6 Survey Results – Habitats

7.6.1 Within the Study Area, habitats identified included watercourse, developed area, sandy shore, woodland, marsh, abandoned agricultural land, shrubland/grassland and marine water. Distribution and representative photo of each habitat were presented in Figure 7.2 and Appendix 7A respectively.

Watercourse

7.6.2 Two main watercourses – Wang Tong River & River Silver – and several minor watercourses were identified in the Study Area.

Wang Tong River

7.6.3 Wang Tong River was semi-channelized and ran straight below the proposed bridge. No sailing on the Wang Tong River was observed.

7.6.4 The upper reach of the River (north of Tai Wai Yuen) was fully channelized with concrete streambed and banksides. Only a few vegetation (e.g. Ficus subpisocarpa) was found along the River. Besides, wastewater was discharged from several points on banksides. In this upper reach section, the water level was not influenced by the tidal action during the site visits.

7.6.5 The middle reach of the River (west of Tai Wai Yuen) was semi-channelized by concrete and/or boulder, with a natural streambed which consisted of sand and gravels. Vegetation composition on banksides was highly depended on the habitat (Woodland & Developed Area). Tree such as Hibiscus tiliaceus and Litsea glutinosa were found on the bankside in Woodland, while exotic landscape and fruit plants such as Wedelia trilobata and Syzygium samarangense were found on the bankside in Developed Area. In this middle reach section, the water level was affected by the tidal action.

7.6.6 The lower reach of the River (south of Tai Wai Yuen) was semi-channelized by concrete and boulders, with a natural streambed which consisted of silt, sand and gravels, while mud accumulated at location with slower water flow (e.g. with wider width or at bend). The northern bank was a woodland which was dominated by Hibiscus tiliaceus, while the southern bank was an exposed artificial bank. Besides vegetation on bankside, true and associated mangrove species (Aegiceras corniculatum and Acanthus ilicifolius) were found in the River. In this lower reach section, the water level was strongly affected by tidal action. The streambed could be exposed during very low tide.

7.6.7 At the discharge point of the River, an alluvial fan was formed. The alluvial fan was consisted of sand and was not vegetated. The course running on the alluvial fan changed over time (e.g. changing from a straight course in wet season 2014 to a winding course in dry season 2014/2015).

7.6.8 2 fish species (Predaceous chub Parazacco spilurus and Indo-Pacific tropical sand goby Favonigobius reichei) and 2 avifauna species with conservation importance (Little Egret Egretta garzetta & White-throated Kingfisher Halcyon smyrnensis) were recorded in Wang Tong River.

River Silver

7.6.9 The River Silver was channelized and was about 200m south from the Project site. Although its water level was affected by tidal action, its stream-bed was not visible even in low tide. Sampans were sailed on the River.

7.6.10 1 avifauna species with conservation importance – Little Egret (Egretta garzetta) – was recorded on the bankside of River Silver.

Minor watercourses

7.6.11 Several minor watercourses were identified in the Study Area. Most of them were located in/around Tai Wai Yuen and converge to the Wang Tong River. Some of them had only seasonal water flow.

7.6.12 1 fish species with conservation importance – Small Snakehead (Channa asiatica) – was recorded in these minor watercourses.

Developed Area

7.6.13 The Study Area was dominated by Developed Area. Areas of disturbed habitat found within the Study Area, such as residential areas and recreational grounds, were regarded as Developed Area. Vegetation and trees found in this habitat were mostly exotic and cultivated (e.g. Aglaia odorata var. microphyllina, Duranta erecta & Terminalia catappa).

7.6.14 2 uncommon butterfly species (Plain Tiger Danaus chrysippus chrysippus and Common Redeye Matapa aria) were found in Developed Area.

Sandy Shore

7.6.15 Sandy Shores in the Study Area were located in both the intertidal zone and area above high water mark. Most Sandy Shore in the Study Area was not vegetated and was utilized for recreational use (i.e. the Silvermine Bay Beach). Only a few plant species (e.g. Ipomoea pes-caprae) and cultivated trees (e.g. Terminalia catappa) were found.

7.6.16 2 avifauna species with conservation importance – Little Egret (Egretta garzetta) & Pacific Reef Heron (Egretta sacra) – were recorded in Sandy Shore.

Woodland

7.6.17 Most of the undisturbed terrestrial area in the Study Area were Woodland. Nevertheless, the species composition of woodland was not consistent throughout the Study Area. For the woodland adjacent to the downstream Wang Tong River, it was dominated by Hibiscus tiliaceus with a 3 – 6 m canopy height. Trees Microcos nervosa and Tarenna attenuate, shrub Sageretia thea and climber Morinda parvifolia could be found further upstream. Regarding the woodland on the Butterfly Hill, its canopy was about 6 – 10 m in height and was not dominated by any species. Species included Celtis sinensis, Ficus spp. and Schefflera heptaphylla were found in canopy, while Daphniphyllum calycinum, Ilex asprella and Litsea rotundifolia var. oblongifolia were found in understorey.

7.6.18 1 plant and 1 avifauna species with conservation importance – Aquilaria sinensis & Greater Coucal (Centropus sinensis) respectively – were recorded in Woodland. A very rare butterfly (Metallic Cerulean Jamides alecto alocina) and an uncommon butterfly (Striped Blue Crow Euploea mulciber mulciber) were also recorded in this habitat.

Marsh

7.6.19 A single piece of Marsh was found in Tai Wai Yuen. It was a fairly flat ground historically used for agriculture, and was now overgrown with true mangrove species Acrostichum aureum and herbs such as Cyperus involucratus. It was surrounded by Hibiscus tiliaceus dominated woodland. Watercourses converged to the Wang Tong River. Presence of plant species that are adapted to salty environment demonstrated the tidal influence in Tai Wai Yuen. The degree of wetness varied upon seasons.

7.6.20 4 avifauna species – Eastern Cattle Egret (Bubulcus coromandus), Little Egret (Egretta garzetta), White-throated Kingfisher (Halcyon smyrnensis) & Black-crowned Night Heron (Nycticorax nycticorax) – with conservation importance were recorded in this habitat.

Abandoned Agricultural Land

7.6.21 Abandoned Agricultural Lands were found at the northern and western edges of the Study Area. They had fairly flat grounds, while some areas had water-bogged soil in wet season. Plants such as Zingiber officinale and Ludwigia spp. and Azolla imbricata were found. Presence of freshwater species demonstrated that the land might not experience tidal influence.

7.6.22 A very rare butterfly species – Metallic Cerulean (Jamides alecto alocina) – was recorded in Abandoned Agricultural Land.

Shrubland/Grassland

7.6.23 Patches of Shrubland/Grassland were recorded in the Study Area. A large piece was found on hillside near the northern edge of the Study Area. Small patches were also scattered within / adjacent to Woodland in the Study Area. Vegetation such as Melastoma sanguineum and Mikania micrantha were recorded in this habitat.

7.6.24 No species with conservation importance or rare species was found in this habitat.

Marine Water

7.6.25 Marine Water was found in the eastern part of the Study Area. It receives discharge of 2 watercourses – Wang Tong River & River Silver. This habitat was disturbed by human activities including marine traffic (i.e. sailing) and recreational uses (e.g. bathing beach).

The Project Site

7.6.26 The proposed twin bridges are located across the lower reach (very close to discharge point) of Wang Tong River. Instead of concrete, the streambed where bridges cross was natural and comprised by sand and gravels. The northern reach of bridges was sandy shore, while the southern reach was a mixture of sandy shore and artificial bank. Both reaches were mostly exposed with a few vegetation and cultivated trees (e.g. Macaranga tanarius var. tomentosa and Terminalia catappa). Since the water level of the downstream Wang Tong River was influenced by tidal action, the size of sandy shore and artificial bank were affected by tidal action. Representative photos of the Project Site are shown in Appendix 7D.

7.6.27 No species with conservation importance or rare species was found on the Project Site.

7.7 Survey Results – Flora and Fauna

7.7.1 This section summarizes flora and fauna recorded throughout the survey period. A species list with details on distribution, rarity and conservation status can be found in Appendix 7B. Locations of species with conservation importance and nesting sites of Amaurornis phoenicurus, Gracupica nigricollis and Hirundo rustica found in the Study Area are presented in Figure 7.2. Photographic records of species with conservation importance were presented in Appendix 7C.

Vegetation

7.7.2 200 plant species were recorded in the Study Area. Both native and exotic species were recorded in the Study Area. 8 species recorded – 2 native and 6 exotic species – have conservation statuses, which were shown in Table 7.4. Nevertheless, only Aquilaria sinensis was considered to be a species with conservation importance. The rest are cultivated individuals and are common cultivated species in Hong Kong. Hence, they are not considered to be with conservation importance.

Table 7.4: Plant species with conservation statuses recorded within the Study Area in recent surveys (Hu et al. 2003; IUCN 2014)

Species Name (Chinese Name)	Origin	Conservation Status
Aquilaria sinensis (土沉香)	Native	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) 2. Listed as “Near Threatened” in Rare and Precious Plants of Hong Kong 3. Listed as “Vulnerable” in China Plant Red Data Book 4. Listed as “Vulnerable” by the IUCN Red List
Araucaria heterophylla (異葉南洋杉)	Exotic	1. Listed as “Vulnerable” by the IUCN Red List
Dimocarpus longan (龍眼)	Exotic	1. Listed as “Near Threatened” by the IUCN Red List
Dypsis lutescen (散尾葵)	Exotic	1. Listed as “Near Threatened” by the IUCN Red List
Lagerstroemia speciosa (大花紫薇)	Exotic	1. Protected under the Forests and Countryside Ordinance (Cap. 96)
Platycladus orientalis (側柏)	Exotic	1. Listed as “Near Threatened” by the IUCN Red List
Rhododendron pulchrum (錦繡杜鵑)	Exotic	1. Protected under the Forests and Countryside Ordinance (Cap. 96)
Rhododendron simsii (紅杜鵑)	Native	1. Protected under the Forests and Countryside Ordinance (Cap. 96)

Terrestrial Mammal

7.7.3 2 terrestrial mammal species – Domestic Ox (Bos taurus) & Domestic Water Buffalo (Bubalus bubalis) – were recorded in the Study Area. A herd of 14 individuals of Domestic Ox marched from Developed Area and rest on beach. This species is widely distributed and common in Hong Kong. One individual of Domestic Water Buffalo was found in Tai Wai Yuen. It has restricted distributed and is locally uncommon (AFCD 2014).

7.7.4 Although no breeding behaviour was observed, juveniles of Domestic Ox were found in the herd.

Avifauna

7.7.5 37 avifauna species were recorded in the Study Area. Except the Pacific Reef Heron (Egretta sacra) is uncommon, all species recorded – including Crested Myna (Acridotheres cristatellus) and Eurasian Tree Sparrow (Passer montanus) – are common in Hong Kong (AFCD 2014). Except the Grey Heron (Ardea cinerea) has restricted distribution, all species recorded – such as Black-collared Starling (Gracupica nigricollis) and Common Tailorbird (Orthotomus sutorius) – are widely distributed in Hong Kong.

7.7.6 All wild birds are protected under the Wild Animals Protection Ordinance (Cap. 170). Besides being protected under Cap. 170, 9 species recorded – Great Egret (Ardea alba), Grey Heron (A. cinerea), Eastern Cattle Egret (Bubulcus coromandus), Greater Coucal (Centropus sinensis), Little Egret (Egretta garzetta), Pacific Reef Heron (E. sacra), White-throated Kingfisher (Halcyon smyrnensis), Black Kite (Milvus migrans) and Black-crowned Night Heron (Nycticorax nycticorax) – are considered as species with conservation importance. Their conservation statuses were presented in Table 7.5.

Table 7.5: Avifauna species of conservation importance recorded within the Study Area in recent surveys (Fellowes et al. 2002; Zheng & Wang 1998)

Common Name (Species Name)	Conservation Status
Great Egret (Ardea alba)	1. Listed as “Regional Concern” by Fellowes et al. (2002)
Grey Heron (Ardea cinerea)	1. Listed as “Potential Regional Concern” by Fellowes et al. (2002)
Eastern Cattle Egret (Bubulcus coromandus)	1. Listed as “Local Concern” by Fellowes et al. (2002)
Greater Coucal (Centropus sinensis)	1. Listed as “Vulnerable” in China Red Data Book Status by Zheng & Wang (1998)
Little Egret (Egretta garzetta)	1. Listed as “Regional Concern” by Fellowes et al. (2002)
Pacific Reef Heron (Egretta sacra)	1. Listed as “Rare” in China Red Data Book Status by Zheng & Wang (1998) 2. Listed as “Local Concern” by Fellowes et al. (2002)
White-throated Kingfisher (Halcyon smyrnensis)	1. Listed as “Local Concern” by Fellowes et al. (2002)
Black Kite (Milvus migrans)	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) 2. Listed as “Regional Concern” by Fellowes et al. (2002)
Black-crowned Night Heron (Nycticorax nycticorax)	1. Listed as “Local Concern” by Fellowes et al. (2002)
All birds are protected under the Wild Animals Protection Ordinance (Cap. 170). * Species listed as “Least Concern” by IUCN Red List were not included

Common Name

(Species Name)

Conservation Status

Great Egret

(Ardea alba)

1. Listed as “Regional Concern” by Fellowes et al. (2002)

Grey Heron

(Ardea cinerea)

1. Listed as “Potential Regional Concern” by Fellowes et al. (2002)

Eastern Cattle Egret

(Bubulcus coromandus)

1. Listed as “Local Concern” by Fellowes et al. (2002)

Greater Coucal

(Centropus sinensis)

1. Listed as “Vulnerable” in China Red Data Book Status by Zheng & Wang (1998)

Little Egret

(Egretta garzetta)

1. Listed as “Regional Concern” by Fellowes et al. (2002)

Pacific Reef Heron
(Egretta sacra)

1. Listed as “Rare” in China Red Data Book Status by Zheng & Wang (1998)

2. Listed as “Local Concern” by Fellowes et al. (2002)

White-throated Kingfisher

(Halcyon smyrnensis)

1. Listed as “Local Concern” by Fellowes et al. (2002)

Black Kite

(Milvus migrans)

1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586)

2. Listed as “Regional Concern” by Fellowes et al. (2002)

Black-crowned Night Heron

(Nycticorax nycticorax)

1. Listed as “Local Concern” by Fellowes et al. (2002)

*All birds are protected under the Wild Animals Protection Ordinance (Cap. 170).

** Species listed as “Least Concern” by IUCN Red List were not included

7.7.7 Active nest of White-breasted Waterhen (Amaurornis phoenicurus) was found in Woodland adjacent to Wang Tong River, while active nests of Black-collared Starling (Gracupica nigricollis) and Barn Swallow (Hirundo rustica) were found in Developed Area. Immature individuals of Crested Myna (Acridotheres cristatellus), Barn Swallow (Hirundo rustica) and Eurasian Tree Sparrow (Passer montanus) were recorded in Developed Area, while immature individuals of Oriental Magpie Robin (Copsychus saularis) were recorded on Sandy Shore and Wang Tong River.

Herpetofauna

7.7.8 1 amphibian species (Gunther's Frog Hylarana guentheri) was heard in Tai Wai Yuen, and 2 reptile species – Changeable Lizard Calotes versicolor & Bowring’s Gecko Hemidactylus bowringii – were recorded in Developed Area in the Study Area. All of them are distributed throughout Hong Kong. No species with conservation importance was recorded.

7.7.9 Although no breeding behaviour was recorded, immature individuals of Changeable Lizard (Calotes versicolor) were found in Developed Area.

Butterfly

7.7.10 30 butterfly species were recorded in the Study Area, over half of which were found in Developed Area. 26 species, including Large Faun (Faunis eumeus eumeus) & Common Mormon (Papilio polytes polytes), are widespread and are either very common or common in Hong Kong (AFCD 2014). 3 species – Plain Tiger (Danaus chrysippus chrysippus), Striped Blue Crow (Euploea mulciber mulciber) & Common Redeye (Matapa aria) – are uncommon in Hong Kong. Common Redeye is widespread in Hong Kong, while Plain Tiger and Striped Blue Crow have limited distribution in Hong Kong. One very rare butterfly species, Metallic Cerulean (Jamides alecto alocina), was also recorded in Woodland and Abandoned Agriculture Land. It has limited distribution in Hong Kong.

7.7.11 Metallic Cerulean is considered as species with conservation importance because of its rarity in Hong Kong.

7.7.12 Angled Castor (Ariadne ariadne alterna) was recorded laying eggs on Ricinus communis in Developed Area. Larvae of Angled Castor were also found on Ricinus communis in Developed Area.

Odonate

7.7.13 8 odonate species, including Yellow Featherlegs (Copera marginipes) & Wandering Glider (Pantala flavescens), were recorded in the Study Area. All of them are widely distributed and are abundant in Hong Kong (AFCD 2014). All species recorded are not considered as species with conservation importance.

7.7.14 No breeding behaviour and no immature individual were recorded.

Freshwater Fish

7.7.15 13 fish species were recorded in the Study Area. Except the Small Snakehead (Channa asiatica) is uncommon and has restricted distribution, all species – including Grey mullet (Mugil cephalus), Common Mudskipper (Periophthalmus modestus) and Jarbua Terapon (Terapon jarbua) – are common and widespread in Hong Kong (AFCD 2014).

7.7.16 3 recorded species – Small Snakehead (Channa asiatica), Indo-Pacific tropical sand goby (Favonigobius reichei) and Predaceous chub (Parazacco spilurus) – are considered as species with conservation importance. Status of each species is presented in Table 7.6.

Table 7.6: Fish Species of Conservation Importance Recorded Within the Study Area in Recent Surveys (Wang, Yue & Chen 1998; Fellowes et al. 2002; IUCN 2014)

Common Name (Species Name)	Conservation Status
Small snakehead (Channa asiatica)	l Listed as “Local Concern” by Fellowes et al. (2002)
Indo-Pacific tropical sand goby (Favonigobius reichei)	l Listed as “Near Threatened” by the IUCN Red List
Predaceous chub (Parazacco spilurus)	l Listed as “Vulnerable” by the China Red Data Book Status (Wang, Yue & Chen 1998)

7.7.17 Although no breeding behaviour was recorded, immature individuals of Goby (Gobiidae), Mangrove snapper (Lutjanus argentimaculatus), Grey mullet (Mugil cephalus), Predaceous chub (Parazacco spilurus), Spotted scat (Scatophagus argus), White-spotted rabbit fish (Siganus canaliculatus) and Jarbua terapon (Terapon jarbua) were found in Wang Tong River, demonstrating its importance as fish nursery ground.

Crustacean

7.7.18 3 crustacean species – Ligia exotica, Ocypode ceratophthalma & Uca crassipes – were recorded in the Study Area. No species with conservation importance was recorded.

7.7.19 Although no breeding behaviour or berried individual was recorded, immature individuals of Ocypode ceratophthalma were recorded on Sandy Shore.

Mollusca

7.7.20 3 mollusca species – Anomalocardia sp., Batillaria zonalis & Meretrix meretrix – were recorded on Sandy Shore. All of them are not considered as species with conservation importance.

7.8 Evaluation of Habitat

7.8.1 The ecological value of habitats have been evaluated according to EIAO-TM Annex 8 Table 2.

Table 7.7: Ecological Value of Watercourse – Wang Tong River

Criteria	Watercourse – Wang Tong River
Naturalness	Semi-artificial
Size (Length)	~ 660 m
Diversity	Low to moderate flora & fauna diversity
Rarity	Habitat: Common in Hong Kong Species: 2 avifauna species – Little Egret & White-throated Kingfisher – and 2 fish species – Indo-Pacific tropical sand goby & Predaceous chub – with conservation importance were recorded in recent surveys.
Recreatability	Difficult to Recreate
Fragmentation	Very Minor
Ecological linkage	Linked with woodland on bankside, marsh, sandy shore & marine water.
Potential value	Moderate, if all domestic discharge points are removed
Nursery / breeding ground	Nursery ground of 1 avifauna (Oriental Magpie Robin) and 7 fish species (Goby, Mangrove snapper, Grey mullet, Predaceous chub, Spotted scat, White-spotted rabbit fish & Jarbua terapon)
Age	N.A.
Abundance/ Richness of Wildlife	Low – Moderate
Ecological value	Low – Moderate

Table 7.8: Ecological Value of Watercourse – River Silver & Minor Watercourses

Criteria	Watercourse
Criteria	River Silver	Minor Watercourses
Naturalness	Artificial	Natural or Semi-artificial
Size (Length)	~ 430 m	N.A.
Diversity	Low flora & fauna diversity
Rarity	Habitat: Common in Hong Kong Species: 8 avifauna species having conservation importance – Great Egret, Grey Heron, Chinese Pond Heron, Eastern Cattle Egret, Striated Heron, Little Egret, White-throated Kingfisher & Black-crowned Night Heron – were recorded in past study, while 1 avifauna species with conservation importance – Little Egret – was recorded in recent surveys.	Habitat: Common in Hong Kong Species: 1 fish species with conservation importance – Small snakehead – was recorded in recent surveys.
Recreatability	Difficult to Recreate	Difficult to Recreate
Fragmentation	Un-fragmented
Ecological linkage	Linked with marine water and three major tributaries in Pak Ngan Heung, Luk Tei Tong and Tai Tei Tong	Linked with Wang Tong River
Potential value	Low
Nursery / breeding ground	No nursery or breeding ground identified
Age	N.A.
Abundance/ Richness of Wildlife	Very Low
Ecological value	Low	Low

Table 7.9: Ecological Value of Developed Area and Sandy Shore

Criteria	Developed Area	Sandy Shore
Naturalness	Artificial	Naturally formed, and utilized for recreational use
Size / Length	~ 22.2 ha	~ 670 m
Diversity	Low to moderate flora & fauna diversity, but largely exotic	Low flora & fauna diversity
Rarity	Habitat: Common in Hong Kong Species: 2 uncommon butterfly species were recorded in recent surveys	Habitat: Common in Hong Kong Species: 2 avifauna species with conservation importance – Little Egret & Pacific Reef Heron – were recorded in recent surveys
Recreatability	Recreateable	Difficult to Recreate
Fragmentation	Minor	Fragmented by Wang Tong River
Ecological linkage	No significant ecological linkage to surrounding was identified	Linked with Wang Tong River & marine water
Potential value	Low
Nursery / breeding ground	Nursery ground of 3 avifauna (Crested Myna, Barn Swallow & Eurasian Tree Sparrow), 1 lizard (Changeable Lizard) and 1 butterfly species (Angled Castor). Breeding ground of 2 avifauna (Black-collared Starling & Barn Swallow) and 1 butterfly species (Angled Castor).	Nursery ground of 1 mammal (Domestic Ox), 1 avifauna (Oriental Magpie Robin) and 1 crustacean species (Ocypode ceratophthalma)
Age	Major development within 40 years	N.A.
Abundance/ Richness of Wildlife	Low to moderate	Very Low
Ecological value	Low	Low

Table 7.10: Ecological Value of Woodland and Marsh

Criteria	Woodland	Marsh
Naturalness	Natural	Natural
Size	~ 21.4 ha	~ 1.9 ha
Diversity	Low flora & fauna diversity
Rarity	Habitat: Common in Hong Kong Species: 2 plant species with conservation importance – Aquilaria sinensis & Diospyros vaccinioides – were recorded in past study. 1 plant species (Aquilaria sinensis), 1 avifauna (Greater Coucal) & 1 butterfly (Metallic Cerulean) species with conservation importance were recorded in recent surveys. 1 uncommon butterfly species was also recorded in recent surveys.	Habitat: Uncommon in Hong Kong Species: 4 avifauna species with conservation importance – Eastern Cattle Egret, Little Egret, White-throated Kingfisher & Black-crowned Night Heron – were recorded in recent surveys 1 uncommon mammal species was found in recent surveys.
Recreatability	Difficult to Recreate	Difficult to Recreate
Fragmentation	Minor	Un-fragmented
Ecological linkage	Linked with Wang Tong River
Potential value	Low
Nursery / breeding ground	Breeding ground of 1 avifauna species (White-breasted Waterhen)	No nursery or breeding ground identified
Age	N.A.	N.A.
Abundance/ Richness of Wildlife	Low	Low
Ecological value	Low - Moderate	Low

Table 7.11: Ecological Value of Abandoned Agricultural Land and Shrubland/Grassland

Criteria	Abandoned Agricultural Land	Shrubland/Grassland
Naturalness	Semi-artificial	Natural
Size	~ 2.1 ha	~ 2.9 ha
Diversity	Very low flora & fauna diversity
Rarity	Habitat: Common in Hong Kong Species: 1 butterfly (Metallic Cerulean) species with conservation importance was recorded in recent surveys	Habitat: Common in Hong Kong Species: No species with conservation importance was recorded
Recreatability	Recreateable	Recreateable
Fragmentation	Minor – Moderate
Ecological linkage	Near woodland in Butterfly Hill	No significant ecological linkage to surrounding was identified
Potential value	Low
Nursery / breeding ground	No nursery or breeding ground identified	No nursery or breeding ground identified
Age	10 - 20 years	N.A.
Abundance/ Richness of Wildlife	Low	Very Low
Ecological value	Low	Very Low

Table 7.12: Ecological Value of Marine Water

Criteria	Marine Water
Naturalness	Natural
Size	~ 23.5ha
Diversity	Low
Rarity	Habitat: Common in Hong Kong Species: No species with conservation importance was recorded
Recreatability	Difficult to Recreate
Fragmentation	Not fragmented
Ecological linkage	Linked with Wang Tong River and River Silver
Potential value	Low
Nursery / breeding ground	No nursery or breeding ground identified
Age	N.A.
Abundance/ Richness of Wildlife	Low
Ecological value	Low

7.9 Identification of Ecological Impacts

7.9.1 The Project could be divided into 3 major parts: 1.) construction of the new cycle bridge, 2.) demolition of the Old Bridge, and 3.) re-construction of pedestrian bridge. Habitats where bridges connected and where supporting piers were/will be located would be impacted directly. Surrounding habitats and their associated communities would be impacted indirectly by liquid contamination (water quality impact) and noise in construction and/or operational phases. No direct impact on intertidal / marine water habitats and their associated fauna is expected, as no marine works will be involved in this Project and construction equipment will be delivered to the Site on land after unloading at Mui Wo Pier.

7.9.2 Besides the breeding ground of Black-collared Starling (see Section 7.9.4 for details) and the nursery ground of Oriental Magpie Robin (see Section 7.9.5 for details) and 7 fish species (see Section 7.9.6 for details), no species of conservation importance and breeding/nursery ground would be impacted directly by the Project.

Construction Phase

Direct Impact

7.9.3 Twin bridges will be constructed in sequence in order to maintain access across Wang Tong River. Each bridge will take around nine months to complete. The temporary work boundary of the Project would take up about 902m² of Sandy Shore (in which 226m² will be lost permanently as new abutments and columns, see Section 7.9.13 & Figure 7.3 for details), 204m² of Developed Area, and 91m² of Wang Tong River (see Figure 7.3). Affected Sandy Shore and Developed Area were mostly exposed with sand and concrete respectively. Vegetation found was limited, and was mainly ruderal species (e.g. Cenchrus echinatus and Melinis repens) with some cultivated trees (e.g. Casuarina equisetifolia and Terminalia catappa). No species with conservation importance was recorded in the directly affected area. 7 cultivated trees (2 individuals of Casuarina equisetifolia, 3 individuals of Macaranga tanarius var. tomentosa and 2 individuals of Terminalia catappa) on Sandy Shore and Developed Area encroached the Project alignment, hence they would be removed by either tree felling or transplantation.

7.9.4 Although a nest of Black-collared Starling (Gracupica nigricollis) was recorded on a Casuarina equisetifolia in the proposed works area, the individual of C. equisetifolia with bird nest would be retained. Also, as the breeding activity of Black-collared Starling does not rely on specific species and similar habitat (i.e. tall tree canopy) can easily be found in the surrounding, impact on the breeding activity of Black-collared Starling would be minor if the proposed mitigation measure (see Section 7.11 for details) is implemented properly.

7.9.5 Although Wang Tong River and Sandy Shore (i.e. nursery grounds of Oriental Magpie Robin) would be impacted directly, the impacted area will be small (see Table 7.13). In addition, much of these habitats will remain unaffected. Therefore, the direct impact on nursery grounds of Oriental Magpie Robin would be insignificant.

7.9.6 Although the working area would encroach upon Wang Tong River, the River will only be narrowed by the cofferdam at the high water mark and the pier of Old Bridge in water. The water flow will not be completely blocked. No species with conservation importance was recorded in the directly affected area. Although the Wang Tong River was a nursery ground of 7 fish species (Goby, Mangrove snapper, Grey mullet, Predaceous chub, Spotted scat, White-spotted rabbit fish & Jarbua terapon), the impacted area would be small and the impact would only be short term. Therefore, direct impact on the fish nursery ground would be minor and reversible.

7.9.7 Despite there will be 971 m²temporary and 226 m²permanent (see Section 7.9.13) loss due to the new bridge construction (breakdown of each habitat is shown on Table 7.13), the affected area is relatively small in size, and hence the direct impact caused by the Project in construction phase will be minor.

Table 7.13: Summary of Habitat Loss

Habitats	Directly Impacted Area
Habitats	Permanent	Temporary	Total
Watercourse – Wang Tong River	-	91 m²	91 m²
Developed Area	-	204 m²	204 m²
Sandy Shore	226 m²	676 m²	902 m²
Total	226 m²	971 m²	1197 m²

Indirect Impact – Water Quality

7.9.8 Although part of the working area will encroach Wang Tong River for establishing new bridges abutments, it will only occupy a small area along the edge of high water mark. No significant change in hydrodynamic in Wang Tong River is expected. Also, the working area will only impact on the River for short term (about 9 months for each bridge in construction phase only). During demolishing existing bridge column, a cofferdam extending 1m from the existing pier will be erected in the center of the river. Nevertheless, the working area will not block the river flow in both low and high tide, and the pier removal work is expected to last for a week only. Also, there will be minor improvement in water flow after removal of the pier. The construction impact on hydrodynamic will be small and temporary while the overall impact will be positive.

7.9.9 As the working area will encroach and close to Wang Tong River, if excavation is carried out within the course of the River without protection measures, surface runoff during heavy rain and accidental discharge of silty wastewater may increase suspended solids level in water. Accidental spillage of chemicals and untreated sewage could contaminate the River and cause water quality impact if uncontrolled. Water pollution in large quantity may affect the health and survival of wildlife in intertidal and marine water habitats as they are sensitive to water quality.

7.9.10 Nevertheless, the amount of water pollution will not be significant due to small project scale. Also, with proper implementation of water quality mitigation measures detailed in Section 7.11, the overall water quality impact on water courses and marine habitats during construction phase will be minor. Some of the mitigation measures are listed below:

· establishment of water-tight cofferdam around excavation area

· provision of working platform above water that can prevent falling of objects into water

· encourage workers to use nearby public toilets in Chung Hau Village and in Silvermine Bay Beach by placing signs onsite to direct their locations

· position chemical toilet away from waterbodies as far as possible and on stable, impermeable surface to minimize accidental leakage of sewage into waterbodies (i.e. placing chemical toilet with a drip tray underneath near the northern boundary of the working area on the northern shore, which is of the greatest distance from Wang Tong River)

Indirect Impact – Noise

7.9.11 Noise produced in construction phase can be a nuisance to wildlife. The major noise sources would be the use of powered mechanical equipment (PME). While mitigation measures proposed in Chapter 4 – Noise Impact Assessment (e.g. use of silenced plants or quality powered mechanical equipment (QPME) and erection of noise barrier) shall be implemented to minimize the noise transmission, the residual noise would inevitably deter wildlife to utilize the nearby areas. Nevertheless, since the construction works would be localized the noise impact would be short term (about 9 months for each bridge), the overall noise impact in construction phase will be acceptable.

Cumulative Impact

7.9.12 Referring to Section 2.8, there are one planned and one ongoing projects within the Study Area: (1) Signature Project Scheme (Islands District) – Improvement Works at Silvermine Bay Beach, Mui Wo, Lantau Island by the Home Affairs Department (HAD) ; and (2) Upgrading of Mui Wo Sewage Treatment Works and Village Sewerage at Wang Tong and Yue Kwong Chuen managed by the DSD (Drainage Services Department). The programme of the former project will not overlap with that of this Project. The latter project involves minor works that do not require use of powered plant equipment or dusty works (e.g. painting works). No cumulative impact is expected.

Operational Phase

Direct Impact

7.9.13 About 226m² of Sandy Shore in total (i.e. about 222m² for abutments and about 4m² for columns, see Figure 7.3 for details) will be permanently lost due to the Project , which is currently grown with cultivated trees. Nevertheless, as the existing bridge column in Wang Tong River will be demolished and no column or abutment will locate or encroach the Wang Tong River, the Project will permanently release about 0.18m² (or 0.35m in width) of the River. Since the ecological value of Sandy Shore is low and the permanently lost habitat is small in area, the direct impact caused by the Project in operational phase will be very minor.

Indirect Impact – Water Quality

7.9.14 Since no new column will be established in the River, the flow of River will not be blocked by the Project. As the Old Pier is not wide, removal of the pier is not expected to bring significant change in hydrodynamics of the river. Besides, as the Project will not generate wastewater, no water quality impact is expected in operational phase.

Indirect Impact – Noise

7.9.15 The New Bridge will replace the Old Bridge to serve as cycle track and footpath, no noise impact is expected in operational phase.

7.10 Evaluation of Ecological Impacts

7.10.1 The significance of ecological impact have been evaluated according to EIAO-TM Annex 8 Table 1 and Table 3.

Table 7.14: Evaluation of the significance of ecological impact on Watercourse – Wang Tong River

Criteria	Watercourse – Wang Tong River
Habitat quality	Low – Moderate
Species	2 avifauna & 2 fish species with conservation importance were found in recent surveys Overall low to moderate diversity & abundance
Impact Size / Abundance	Very small in size (i.e. ≈ 91 m²) would be impacted directly Low to moderate number of fauna.
Impact Duration	Temporary loss as work area (≈ 91 m²) in construction phase, but permanent release of existing bridge column in Wang Tong River (0.18m² in area or 0.35m in width). Indirect impact only in construction phase
Impact Reversibility	Reversible
Impact Magnitude	Habitat Loss: Minor Water Quality: Minor Noise: Minor
Overall Impact	Minor

Table 7.15: Evaluation of the significance of ecological impact on Watercourse – River Silver & Minor Watercourses

Criteria	Watercourse
Criteria	River Silver	Minor Watercourses
Habitat quality	Low	Low
Species	8 avifauna species having conservation importance were recorded in past study, while 1 avifauna species with conservation importance was recorded in recent surveys. Overall low diversity & very low abundance	1 fish species with conservation importance was recorded in recent surveys. Overall low diversity & very low abundance
Impact Size / Abundance	Not directly affected
Impact Duration	Indirect water quality impact only in construction phase
Impact Reversibility	Reversible
Impact Magnitude	Habitat Loss: N.A. Water Quality: Insignificant Noise: Insignificant
Overall Impact	Insignificant	Insignificant

Table 7.16: Evaluation of the significance of ecological impact on Developed Area and Sandy Shore

Criteria	Developed Area	Sandy Shore
Habitat quality	Low	Low
Species	2 uncommon butterfly species were recorded in recent surveys Overall low to moderate diversity & low abundance	2 avifauna species with conservation importance – Little Egret & Pacific Reef Heron – were recorded in recent surveys Overall low diversity & very low abundance
Impact Size / Abundance	Very small in size within the Study Area (i.e. ≈ 204 m²). Very low number of fauna and flora.	Very small in size within the Study Area (i.e. ≈ 902 m²). Very low number of fauna and flora.
Impact Duration	Temporary loss as work area (≈ 204 m²) in construction phase	Permanently loss of ≈ 226 m² for bridge abutments and columns Temporary loss as work area (≈ 676 m²) in construction phase
Impact Reversibility	Reversible	Irreversible for the bridge abutments and columns, reversible for temporary work area
Impact Magnitude	Habitat Loss: Minor Water Quality: Minor Noise: Minor
Overall Impact	Minor	Minor

Table 7.17: Evaluation of the significance of ecological impact on Woodland & Marsh

Criteria	Woodland	Marsh
Habitat quality	Low - Moderate	Low
Species	2 plant species with conservation importance were recorded in past study. 1 plant, 1 avifauna & 1 butterfly species with conservation importance were recorded in recent surveys. 1 uncommon butterfly species was also recorded in recent surveys. Overall low diversity & low abundance	4 avifauna species with conservation importance were recorded in recent surveys. 1 uncommon mammal species was also recorded in recent surveys. Overall low diversity & low abundance
Impact Size / Abundance	Not affected directly
Impact Duration	Indirect noise and water quality impact only in construction phase	Indirect noise and water quality impact only in construction phase
Impact Reversibility	Reversible
Impact Magnitude	Habitat Loss: N.A. Water Quality: Insignificant Noise: Minor
Overall Impact	Minor	Minor

Table 7.18: Evaluation of the significance of ecological impact on Abandoned Agricultural Land & Shrubland/Grassland

Criteria	Abandoned Agricultural Land	Shrubland/Grassland
Habitat quality	Low	Very Low
Species	1 butterfly species with conservation importance was recorded in recent surveys Overall very low diversity & low abundance	No species with conservation importance was recorded Overall very low diversity & very low abundance
Impact Size / Abundance	Not expected
Impact Duration	Not expected
Impact Reversibility	N.A.
Impact Magnitude	Habitat Loss: N.A. Water Quality: N.A. Noise: N.A.
Overall Impact	N.A.	N.A.

Table 7.19: Evaluation of the significance of ecological impact on Marine Water

Criteria	Marine Water
Habitat quality	Low
Species	No species with conservation importance was recorded
Impact Size / Abundance	Not affected directly
Impact Duration	Indirect water quality impact only in construction phase
Impact Reversibility	Reversible
Impact Magnitude	Habitat Loss: N.A. Water Quality: Minor Noise: N.A.
Overall Impact	Very Minor

Species	Habitat Recorded	Habitat Use*	Protection status	Distribution	Rarity	Impact**
Plants
Aquilaria sinensis (土沉香)	Woodland	-	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586) 2. Listed as “Near Threatened” in Rare and Precious Plants of Hong Kong 3. Listed as “Vulnerable” in China Plant Red Data Book 4. Listed as “Vulnerable” by the IUCN Red List	Hainan, Guangdong, Guangxi, Taiwan, Yunnan	Common in Hong Kong	No impact expected
Avifauna***
Great Egret (Ardea alba)	Marine Water	Foraging	1. Listed as “Regional Concern” by Fellowes et al. (2002)	Widely distributed in Hong Kong	Common resident and winter visitor	W.Q.: Minor N.: Minor
Grey Heron (Ardea cinerea)	Marine Water	Foraging	1. Listed as “Potential Regional Concern” by Fellowes et al. (2002)	Found in Deep Bay area, Starling Inlet, Kowloon Park, Cape D'Aguilar	Common winter visitor	W.Q.: Minor N.: Minor
Eastern Cattle Egret (Bubulcus coromandus)	Marsh	Foraging	1. Listed as “Local Concern” by Fellowes et al. (2002)	Widely distributed in Hong Kong	Resident and common passage migrant	W.Q.: Minor N.: Minor
Greater Coucal (Centropus sinensis)	Woodland	NIL.	1. Listed as “Vulnerable” in China Red Data Book Status by Zheng & Wang (1998)	Widely distributed in Hong Kong	Common resident	N.: Minor
Little Egret (Egretta garzetta)	Sandy Shore, Marsh, Watercourse & Marine Water	Foraging	1. Listed as “Regional Concern” by Fellowes et al. (2002)	Widely distributed in coastal area throughout Hong Kong	Common resident	H.L.: Minor W.Q.: Minor N.: Minor
Pacific Reef Heron (Egretta sacra)	Sandy Shore & Marine Water	Foraging	1. Listed as “Rare” in China Red Data Book Status by Zheng & Wang (1998); 2. Listed as “Local Concern” by Fellowes et al. (2002)	Widely distributed in coastal area throughout Hong Kong	Uncommon resident	H.L.: Insignificant W.Q.: Minor N.: Minor
White-throated Kingfisher (Halcyon smyrnensis)	Marsh & Watercourse	NIL.	1. Listed as “Local Concern” by Fellowes et al. (2002)	Widely distributed in coastal areas throughout Hong Kong	Common resident	W.Q.: Minor N.: Minor
Black Kite (Milvus migrans)	Marine Water	NIL.	1. Protected under the Protection of Endangered Species of Animals and Plants Ordinance (Cap. 586); 2. Listed as “Regional Concern” by Fellowes et al. (2002)	Widely distributed in Hong Kong	Common resident and winter visitor	N.: Minor
Black-crowned Night Heron (Nycticorax nycticorax)	Marsh	NIL.	1. Listed as “Local Concern” by Fellowes et al. (2002)	Widely distributed in Hong Kong	Common resident and winter visitor	N.: Minor
Butterfly
Metallic Cerulean (Jamides alecto alocina)	Woodland & Abandoned Agricultural Land	NIL.	-	Victoria Peak, Fung Yuen, Chuen Lung, Mui Wo	Very Rare	No impact expected
Fish
Small snakehead (Channa asiatica)	Watercourse	NIL.	1. Listed as “Local Concern” by Fellowes et al. (2002)	Uncommon in the wild. Records from a few streams in North district and on Lantau Island. The fish is also cultivated in some fish farms and are available from fish market	Uncommon	No impact expected
Indo-Pacific tropical sand goby (Favonigobius reichei)	Watercourse	NIL.	1. Listed as “Near Threatened” by the IUCN Red List	Found in intertidal waters throughout Hong Kong	Common	H.L.: Minor W.Q.: Minor
Predaceous chub (Parazacco spilurus)	Watercourse	NIL.	1. Listed as “Vulnerable” by the China Red Data Book Status (Wang, Yue & Chen 1998)	A widespread species occurring in most unpolluted hill streams in both upper and lower courses	Common	W.Q.: Minor
* Only special behavior recorded, e.g. breeding, will be presented in “Habitat Use” H.L. = Habitat Loss; W.Q. = Water Quality Impact; N. = Noise Impact * All wild birds are protected under the Wild Animals Protection Ordinance (Cap. 170)

7.11 Recommendations & Mitigation Measures

7.11.1 Locations of abutments and columns of new bridges, and the method had undergone several rounds of selection to minimize ecological impacts as detailed in Chapter 2. Recommendations and mitigation measures have been proposed to minimize the ecological impact to acceptable levels based on the following hierarchy: avoidance, minimization and compensation.

7.11.2 Avoidance

· To avoid permanent impact on Wang Tong River, no abutment or support column will be located below high water mark

7.11.3 Minimization

· To minimize impact on the breeding activity of Black-collared Starling, before site clearance, the works area should be inspected by ecologist to confirm no active bird nest is present. If any active bird nest is identified, suitable size of buffer area should be established until the nest is abandoned.

· Erection of hoarding, fencing or provision of clear demarcation of work zones to remind workers not to damage area outside the work boundary

· Designate areas for placement of equipment, materials and wastes away from Wang Tong River and Silver Mine Bay

· To minimize water quality impact, all wastewater would be collected and treated up to standard stipulated in the discharge license before discharge

· To minimize water quality impact, all working areas encroaching Wang Tong River would be enclosed by cofferdam. All water found in the enclosed working areas would be treated as wastewater

· To minimize water quality impact, a solid working platform with toe board would be erected above Wang Tong River underneath the working areas, in order to prevent construction material, waste and/or scraps dropping into the River.

· Impermeable cover (e.g. tarpaulin) shall be erected above the working platform to prevent rainwater from falling into the working area. This can minimize surface runoff from the platform.

· Encourage workers to use nearby public toilets in Chung Hau Village and in Silvermine Bay Beach by placing signs onsite to direct their locations

· Position chemical toilet away from waterbodies as far as possible and on stable, impermeable surface to minimize accidental leakage of sewage into waterbodies (i.e. placing chemical toilet with a drip tray underneath near the northern boundary of the working area on the northern shore, which is of the greatest distance from Wang Tong River)

· Adopt good site practices, adopt QPME (Quality Powered Mechanical Equipment) and install noise barrier with cantilever to minimize noise emission and transmission, see Chapter 4 – Noise Impact Assessment for details).

7.12 Evaluation of Residual Impacts

7.12.1 About 226 m² of Sandy Shore will be permanently lost due to the new bridge construction. The loss of small area of low ecological value habitat is considered acceptable. With proper implementation of mitigation measures, no unacceptable residual impact is anticipated during construction and operational phases.

7.13 Environmental Monitoring and Audit Programme

7.13.1 Regular site audit shall be carried out in construction phase to ensure that the proposed mitigation measures are implemented properly. No monitoring and auditing programme would be required in operational phase.

7.14 Conclusion

7.14.1 Ecological sensitive areas recorded in the Study Area include Wang Tong River and Marsh in Tai Wai Yuen. 2 plants, 1 terrestrial mammal, 15 avifauna, 3 amphibians and 1 freshwater fish species with conservation importance were recorded in past studies, while 1 plant, 9 avifauna, 1 butterfly and 3 fish species with conservation importance were recorded in recent surveys.

7.14.2 Due to the construction of new twin bridges and the demolition of old bridge, small area of Sandy Shore (902 m² in total, in which 226 m²will be lost permanently), Developed Area (204 m² in total temporarily) and Wang Tong River (91 m² in total temporarily) will be impacted directly. No species of conservation importance is expected to be impacted directly. Furthermore, the Project will permanently release about 0.18 m² (or 0.35m in width) of Wang Tong River due to the demolition of the existing supporting column. Since the ecological value of each directly impacted habitat is low or low to moderate and the habitat loss is small in size, the impact due to habitat loss is considered to be minor.

7.14.3 Except Abandoned Agricultural Land & Shrubland/Grassland are not expected to be impacted, other habitats and fauna species in the Study Area are expected to be impacted indirectly by water quality and/or noise impacts in construction phase. Nevertheless, these indirectly impacts will be minor. No indirect impact is expected in operational phase.

7.14.4 With proper implementation of mitigation measures, un-acceptable residual impact is not expected. Regular site audit would only be required in construction phase.

7.14.5 The overall impact on terrestrial and aquatic ecology is considered as acceptable.

7.15 References

Agriculture, Fisheries and Conservation Department (AFCD). (2014). Hong Kong Biodiversity Online. [online] http://www.afcd.gov.hk/english/conservation/hkbiodiversity/database/search.asp. Accessed: 30 October 2014.

Carey G.J., Chalmers M.L., Diskin D.A., Kennerley P.R., Leader P.J., Leven M.R., Lewthwaite R.W., Melville D.S., Turnbull M. & Yong L. (2001): The Avifauna of Hong Kong. Hong Kong Bird Watching Society, Hong Kong SAR.

Chan S.F.K., Cheung K.S., Ho C.Y., Lam F.N. & Tang W.S. (2005): A Field Guide to the Amphibians of Hong Kong. Friends of Country Parks, Cosmos Books Ltd, Hong Kong SAR.

Chong D.H. & Dudgeon D. (1992). Hong Kong stream fishes: an annotated checklist with remarks on conservation status. Memoirs of the Hong Kong Natural History Society 19: 79-112.

ERCL HKU (Ecological Restoration and Conservation Laboratory, The University of Hong Kong) (2012). Reptiles of Hong Kong. [online] http://www.biosch.hku.hk/ecology/hkreptiles/index.html. Accessed: 24 August 2015.

Hong Kong Bird Watching Society (HKBWS). (2015). List of HK Birds. [online] http://www.hkbws.org.hk/BBS/attachment.php?aid=21769. Accessed: 24 August 2015.

Hong Kong Herbarium (2012). Check List of Hong Kong Plants 2012, Agriculture Fisheries and Conservation Department, Hong Kong SAR.

Hu Q., Wu T., Xia N., Xing F., Lai P.C.C. & Yip K. (2003), Rare and Precious Plants of Hong Kong. Agriculture, Fisheries and Conservation Department, Friends of the Country Parks, Cosmos Books Ltd, Hong Kong SAR.

Hung, S.K.Y. (2015). Monitoring of Marine Mammals in Hong Kong Waters (2014-15) Final Report. Hong Kong Cetacean Research Project [online] https://www.afcd.gov.hk/english/conservation/con_mar/con_mar_chi/con_mar_chi_chi/files/Final_Report_201415.pdf. Accessed: 27 July 2015.

IUCN. (2014). IUCN Red List of Threatened Species Version 2014.2. [online] www.iucnredlist.org. Accessed: 31 October 2014.

Lau M.W.N. & Dudgeon D. (1999). Composition and distribution of Hong Kong amphibian fauna. Memoirs of the Hong Kong Natural History Society 22: 1-80.

Metcalf & Eddy Limited (M&EL), (2005). Application No. EIA-110/2005 Drainage Improvements in Southern Lantau. Drainage Services Department, Hong Kong SAR.

Shek C.T. (2006): A Field Guide to the Terrestrial Mammals of Hong Kong. Friends of Country Parks, Cosmos Books Ltd, Hong Kong SAR.

PE&B HKU (Programmes of Ecology & Biodiversity, The University of Hong Kong). (2010). Images of Amphibians of Hong Kong. [online] http://www.biosch.hku.hk/ecology/hkamphibians/index.htm. Accessed: 24 August 2015.

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Tam T.W., Leung K.K., Kwan B.S.P., Wu K.K.Y., Tang S.S.H., So I.W.Y., Cheng J.C.Y., Yuen E.F.M., Tsang Y.M. & Hui W.L. (2011). The Dragonflies of Hong Kong. Friends of Country Parks, Cosmos Books Ltd, Hong Kong SAR.

Wang S., Yue P.Q. & Chen Y. Y. (1998). China Red Data Book of Endangered Animals - Pisces (in Chinese). Science Press, Beijing.

Zheng G. & Wang Q. (1998). China Red Data Book of Endangered Animals - Aves. Science Press, Beijing.

8. Landscape and Visual Impacts

8.1 Introduction

8.1.1 This chapter of the report presents an assessment of the potential landscape and visual impacts associated with the New Wang Tong River Bridge, Mui Wo in accordance with the Environmental Impact Assessment Ordinance (EIAO) and the requirements of the EIA Study Brief (ESB- 256/2013) issued to HyD in March 2013. Both construction and operation impacts are assessed. The project boundary is illustrated in Figure No. 8.1.

8.1.2 The assessment includes:

· A listing of the relevant environmental legislation and guidelines;

· A definition of the scope and contents of the study, including a description of the assessment methodology;

· A review of the relevant planning and development control framework;

· A baseline study providing a comprehensive and accurate description of the baseline landscape resources, landscape character areas, zone of visual influence and key groups of existing and planned visually sensitive receivers (VSRs);

· Identification of the source of landscape and visual impacts;

· Recommendation of appropriate mitigation measures and associated implementation programmes;

· Assessment of the potential landscape and visual impacts, by taking into account the sensitivity of receivers, prediction of the magnitude of change experienced by the receivers and resulting potential impact significance, before and after the mitigation measures; and

· Clear evaluations and explanation with supportive arguments of all relevant factors considered in arriving at the significance thresholds of the landscape and visual impacts.

8.1.3 Colour photographs showing baseline conditions, and photomontages and illustrative materials supporting conclusions are provided and the locations of all viewpoints are clearly mapped. Photomontages at representative locations provide comparison between existing views; proposals on Day 1 after completion without mitigation; on Day 1 after mitigation, and in Year 10 after mitigation.

8.2 Scope and Content of Study

8.2.1 Preliminary Engineering Design Drawings of the proposed bridge construction are provided in Figure 1.1.

8.2.2 Major Work Components generating landscape and visual impacts include the following (refer to Chapter 2 for a more detailed description of the project components and the rationale behind the selected preliminary design):

(i) Demolition of existing footbridge deck and approach ramp to north;

(ii) Demolition of existing footbridge pier;

(iii) Modification of existing waterfront to north and south of bridge;

(iv) Felling of existing trees in vicinity of existing bridge;

(v) Construction of replacement twin bridges (pedestrian and cycle);

(vi) Construction of associated bridge lighting.

8.2.3 The exact layouts, designs and construction methods for individual components are subject to review during the ongoing detailed design stage of the project.

8.2.4 Consideration of Alternative Options

The alternative design options and opportunities available for the scheme in terms of the new bridge alignment, level, structural form, layout and construction methods have been considered and elaborated in Chapter 2 of the EIA.

8.2.5 Limits of Study Area

The limit of the landscape impact study is 500 m beyond the boundary of the works (as stated in the EIA Study Brief), which is shown in Figure 8.1). The limit of the visual impact study is the Zone of Visual Influence (ZVI) of the works during the construction and operation phases (as stated in the EIA study brief, which is illustrated on Figure No. 8.7.2).

The scope of this assessment is be the temporary and permanent landscape and visual impacts resulting from the demolition of the existing footbridge and the construction and operation of the new twin pedestrian and cycle bridges.

8.3 Relevant Legislations, Standards & Guidelines

8.3.1 The following environmental legislation, standards and guidelines are applicable to the evaluation of landscape and visual impacts associated with the construction and operation of the project. Relevant guidelines and practices on tree management published by Greening, Landscape and Tree Management Section (GLTM) of the DEVB are also listed.

(i) Environmental Impact Assessment Ordinance (Cap 499) and the Technical Memorandum on EIA Process (TM-EIAO), particularly Annexes 3, 10, 11, 18, 20 and 21;

· An Ordinance to provide for assessing the impact on the environment of certain projects and proposals, for protecting the environment and for incidental matters.

· The Technical Memorandum sets out the principles, procedures, guidelines, requirements and criteria for the technical content of an environmental impact assessment study brief or environmental impact assessment report.

(ii) Hong Kong Planning Standards and Guidelines;

· The Hong Kong Planning Standards and Guidelines (HKPSG) is a Government manual of criteria for determining the scale, location and site requirements of various land uses and facilities. Relevant chapters include Chapter 4: Recreation, Open Space and Greening; Chapter 10: Conservation and Chapter 11: Urban Design Guidelines.

(iii) Landscape Value Mapping of Hong Kong;

· Essential landscape baseline information to provide a systematic reference framework to facilitate landscape assessment and broad environmental assessment of major projects at territorial level.

(iv) EIAO Guidance Note No. 8/2010;

· The Environmental Impact Assessment Ordinance, (Cap 499) Guidance Note advises on the requirements in vetting Landscape and Visual Impact Assessment of designated projects under the Technical Memorandum on EIA Process for the Environmental Impact Assessment Ordinance.

(v) Town Planning Ordinance (Cap 131) and Town Planning (Amendment) Ordinance 2004;

· To promote the health, safety, convenience and general welfare of the community by making provision for the systematic preparation and approval of plans for the lay-out of areas of Hong Kong as well as for the types of building suitable for erection therein and for the preparation and approval of plans for areas within which permission is required for development.

(vi) Foreshore and Sea-bed (reclamations) Ordinance (Cap 127);

· To provide for the publication of proposals in respect of reclamations over and upon any foreshore and sea-bed; to make provision in respect of objections to the proposals, the payment of compensation and connected matters; and to repeal the Public Reclamations and Works Ordinance (Cap 113, 1984 Ed.) and the Foreshores and Sea Bed Ordinance (Cap 127, 1984 Ed.).

(vii) Forests and Countryside Ordinance (Cap 96) and its subsidiary legislation the Forestry Regulations;

· To consolidate and amend the law relating to forests and plants, and to provide for the protection of the countryside.

(viii) Country Parks Ordinance (Cap 208);

· To provide for the designation, control and management of country parks and special areas.

(ix) Marine Parks Ordinance (Cap 476) and associated subsidiary legislation;

· To provide for the designation, control and management of Marine Parks and Marine Reserves.

(x) Protection of Endangered Species of Animals And Plants Ordinance (Cap. 586);

· To regulate the import, introduction from the sea, export, re-export, and possession or control of certain endangered species of animals and plants and parts and derivatives of those species; and to provide for incidental and connected matters.

(xi) SILTech Publication (1991) – Tree Planting and Maintenance in Hong Kong (Standing Interdepartmental Landscape Technical Group) [11-23];

(xii) GEO publication (1/2009) – Prescriptive Measures for Man-made Slopes and Retaining Walls;

(xiii) GEO 1/2011 – Technical Guidelines on Landscape Treatment for Slopes;

· This publication presents guidance on good practice for landscape treatments for man-made slopes and engineering works on natural terrain in Hong Kong.

(xiv) DEVB TC(W) No. 6/2015 – Maintenance of Vegetation and Hard Landscape Features;

· This circular sets out the departmental responsibilities for maintenance of vegetation and hard landscape features.

(xv) ETWB TCW No. 29/2004 – Registration of Old and Valuable Trees, and Guidelines for their Preservation;

· This circular sets out the procedures for registration of Old and Valuable Trees on unleased Government land within built-up areas and tourist attraction spots in village areas.

(xvi) ETWB TCW No. 5/2005 – Protection of Natural Streams/Rivers from Adverse Impacts Arising from Construction Works;

· This circular provides an administrative framework to better protect all natural streams/rivers from the impacts of construction works. The procedures promulgated under this Circular aim to clarify and strengthen existing measures for protection of natural streams/rivers from government projects and private developments.

(xvii) DEVB TC(W) No. 7/2015 - Tree Preservation;

· This circular sets out the policy on tree preservation, and the procedures for control of tree felling, transplanting and pruning in Government projects.

(xviii) WBTC No. 25/93 – Control of Visual Impact of Slopes;

· This circular outlines the design principles recommended to be used in designing manmade slopes for Public Works projects in order to reduce their adverse visual impact.

(xix) WBTC No. 17/2000 – Improvement to the Appearance of slopes in connection with WBTC 25/93;

· This circular outlines the principles and procedures recommended for all departments involved in new slope formation and in upgrading and maintenance of existing slopes for reducing the aesthetic and environmental impact of slope works.

(xx) WBTC No. 7/2002 – Tree Planting in Public Works;

· This circular affirms the advocated policy on tree planting which adopts a flexible and balanced approach in the planning and design of tree planting for public works projects.

(xxi) Latest Proper Planting Practices and other relevant guidelines issued by DevB (GLTM).

(xxii) DEVB TC(W) No. 2/2013 – Greening on Footbridges and Flyovers

· This Circular updates the policy and requirements for greening on new footbridges and flyovers in built up areas (including metro areas and new towns but excluding country parks).

8.3.2 Review of Relevant Planning and Development Control Framework

· A review will be undertaken of the relevant planning and development control framework for the landscape study area (500 m beyond the limit of the works). This is provided under Section 8.5.2.

8.4 Landscape and Visual Impact Assessment Methodology

8.4.1 General Approach

Landscape and visual impacts shall be assessed separately for the construction and operation phases. The assessment of landscape impacts shall involve the following procedures.

8.4.2 Landscape Impact Methodology

(i) Identification of the baseline Landscape Resources (LRs) and Landscape Character Areas (LCAs) found within the study area. This is achieved by site visits and desk-top studies of topographical maps, information databases and photographs. Reference is also made to the ‘Landscape Value Mapping of Hong Kong’ study.

(ii) Assessment of the degree of sensitivity to change of the LRs and LCAs. This is influenced by a number of factors including whether the resource/character is common or rare, whether it is considered to be of local, regional, national or global importance, whether there are any statutory or regulatory limitations / requirements relating to the resource, the quality of the resource / character, the maturity of the resource, and the ability of the resource/character to accommodate change. The sensitivity of each landscape feature and character area is classified as follows:

High:	Important landscape or landscape resource of particularly distinctive character or high importance, sensitive to relatively small changes
Medium:	Landscape or landscape resource of moderately valued landscape characteristics reasonably tolerant to change
Low:	Landscape or landscape resource, the nature of which is largely tolerant to change

(iii) Identification of potential sources of landscape change. These are the various elements of the construction works and operational procedures that would generate landscape change.

(iv) Identification of the magnitude of landscape change. The magnitude of the change depends on a number of factors including the physical extent of the change, the landscape and visual context of the change – i.e. a set circumstance/facts surrounding the change, the compatibility of the project with the surrounding landscape; and the time-scale of the change - i.e. whether it is temporary (short, medium or long term), permanent but potentially reversible, or permanent and irreversible. Landscape changes have been quantified wherever possible. The magnitude of landscape change is classified as follows:

Large:	The landscape or landscape resource would suffer a major change
Intermediate:	The landscape or landscape resource would suffer a moderate change
Small:	The landscape or landscape resource would suffer slight or barely perceptible changes
Negligible:	The landscape or landscape resource would suffer no discernible change
None:	The landscape or landscape resource would suffer absolutely no impact

(v) Identification of potential landscape mitigation measures. These may take the form of adopting alternative designs or revisions to the basic engineering and architectural design to prevent and/or minimise adverse impacts; remedial measures such as colour and textural treatment of building features; and compensatory measures such as the implementation of landscape design measures (e.g. tree planting, creation of new open space etc.) to compensate for unavoidable adverse impacts and to attempt to generate potentially beneficial long term impacts. A programme for the mitigation measures is provided. The agencies responsible for the funding, implementation, management and maintenance of the mitigation measures are identified and their approvals-in-principle are being sought.

(vi) Prediction of the significance of landscape impacts before and after the implementation of the mitigation measures. By synthesising the magnitude of the various changes and the sensitivity of the various landscape resources it is possible to categorise impacts in a logical, well-reasoned and consistent fashion.

Table 8.1 shows the rationale for dividing the degree of significance into four thresholds, namely insubstantial, slight, moderate, and substantial, depending on the combination of a negligible-small-intermediate-large magnitude of change and a low-medium-high degree of sensitivity of the LRs / LCAs. The significance thresholds are defined as follows:

Substantial:	Adverse / beneficial impact where the proposal would cause significant deterioration or improvement in existing landscape quality
Moderate:	Adverse / beneficial impact where the proposal would cause a noticeable deterioration or improvement in existing landscape quality
Slight:	Adverse / beneficial impact where the proposal would cause a barely perceptible deterioration or improvement in existing landscape quality
Insubstantial:	No discernible change in the existing landscape quality
None	Absolutely no change in the existing landscape quality

Table 8.1: Relationship between Receptor Sensitivity and Magnitude of Change in Defining Impact Significance





Note: The colours in the above table categorise the total spectrum of impacts rising from the lowest value at the bottom left corner to the highest value at the top right corner. It may be seen that for some combination of classification levels of Magnitude of Change and Receptor Sensitivity, there are 2 possible impact significance thresholds. When the Magnitude of Change and Receptor Sensitivity are assessed to be towards the higher ends of each classification level the resultant impact significance would be deemed to be the higher of the two impact significance thresholds.

(vii) Prediction of Acceptability of Impacts. An overall assessment of the acceptability, or otherwise, of the impacts according to the five levels of significance set out in Annex 10 of the EIAO-TM is stated in the conclusion in Section (iv). According to Annex 10, the evaluation of landscape and visual impacts may be classified into five levels of significance based on type and extent of the effects concluded in the EIA study:

· The impact is beneficial if the project will complement the landscape and visual character of its setting, will follow the relevant planning objectives and will improve overall and visual quality;

· The impact is acceptable if the assessment indicates that there will be no significant effects on the landscape, no significant visual effects caused by the appearance of the project, or no interference with key views;

· The impact is acceptable with mitigation measures if there will be some adverse effects, but these can be eliminated, reduced or offset to a large extent by specific measures;

· The impact is unacceptable if the adverse effects are considered too excessive and are unable to mitigate practically;

· The impact is undetermined if significant adverse effects are likely, but the extent to which they may occur or may be mitigated cannot be determined from the study. Further detailed study will be required for the specific effects in question.

8.4.3 Visual Impact Methodology

(i) Landscape and visual impacts are assessed separately for the construction and operation phases. The assessment of visual impacts has involved the following procedures.

(ii) Identification of the Visual Envelope and Zones of Visual Influence (ZVI) during the construction and operation phases. The visual envelope is the area from which any part of the proposed project can be seen and may contain areas, which are fully visible, partly visible and non-visible from the project. The ZVI is the portion of the visual envelope that is within 10 km from the proposed project. Identification of the visual envelope and ZVI is achieved by site visits and desk-top studies of topographic maps and photographs to determine the visibility of the project from various locations. Given the effects of distance and the panoramic qualities of many views, VSRs beyond 10 km from the project will scarcely notice it (and will find it very difficult to distinguish) in their wider views. At these distances, the proposed project will not form a feature of any significance in the VSR’s frame of view and consequently will not influence the visual experience of the VSR. Hence 10 km is considered the ultimate limit of the Zone of Visual Influence.

(iii) Identification of the Visually Sensitive Receivers (VSRs) within the ZVI at construction and operation phases. These are the people who would reside within, work within, play within, or travel through, the ZVI. VSRs at both existing and committed developments will be considered in this assessment.

(iv) Assessment of the degree of sensitivity to change of the VSRs. Factors considered include:

· The type of VSRs, classified according to whether the person is at home, at work, at play, or travelling. Those who view the impact from their homes are considered to be highly sensitive as the attractiveness or otherwise of the outlook from their home will have a substantial effect on their perception of the quality and acceptability of their home environment and their general quality of life. Those who view the impact from their workplace are considered to be only moderately sensitive as the attractiveness or otherwise of the outlook will have a less important, although still material, effect on their perception of their quality of life. The degree to which this applies depends on whether the workplace is industrial, retail or commercial. Those who view the impact while taking part in an outdoor leisure activity may display varying sensitivity depending on the type of leisure activity. Those who view the impact while travelling on a public thoroughfare will also display varying sensitivity depending on the speed of travel.

· Other factors which are considered (as required by EIAO GN 8/2010) include the value and quality of existing views and views from planned developments, the availability and amenity of alternative views, the duration or frequency of view, and the degree of visibility.

(v) The sensitivity of VSRs is classified as follows:

High:	The VSR is highly sensitive to any change in their viewing experience
Medium:	The VSR is moderately sensitive to any change in their viewing experience
Low:	The VSR is only slightly sensitive to any change in their viewing experience

(vi) Identification of the relative numbers of VSRs. This is expressed in terms of whether there are very few, few, many or very many VSRs in any one category of VSR.

(vii) Identification of potential sources of visual impacts. These are the various elements of the construction works and operational procedures that would generate visual impacts.

(viii) Assessment of the potential magnitude of visual change. Factors considered include:

Duration and Frequency of the impact:	Temporary / Permanent: This refers to the long term presence of the visual change – whether it is experienced by the VSR for the whole duration of the construction phase or operation phase, or only part thereof. Intermittent / Continuous: This refers to short term frequency of the visual change - is it always visible (continuous) or only at certain times (intermittent). For example, travelling VSRs may only see the source intermittently as they travel along their journey, whereas residential VSRs may have continuous views from their living room.
Reversibility of the impact:	Reversible / Irreversible
Compatibility of the project with the Visual Backdrop:	High / Medium / Low
Distance of the source of impact from the viewer:	Shortest distance measured in metres (m) between the VSR and the source.
Degree of visibility of Source(s) of Visual Impact:	Full: virtually full uninterrupted view of the source of impact Partial: partial view of the source of impact which is slightly hidden by intervening elements such as buildings, vegetation etc. Obscured: partial view of the source of impact which is largely hidden by intervening elements such as buildings, vegetation etc.
Scale of the development	Small / Medium / Large
Potential Blockage of Existing Views	Full / Partial / Slight / Negligible: The degree to which the source of the impact blocks existing open views currently experienced by the VSR.

(ix) The magnitude of visual change is classified as follows:

Large:	The VSRs would suffer a major change in their viewing experience;
Intermediate:	The VSRs would suffer a moderate change in their viewing experience;
Small:	The VSRs would suffer a small change in their viewing experience;
Negligible:	The VSRs would suffer no discernible change in their viewing experience;
None	The VSRs would suffer absolutely no change in their viewing experience.

(x) Identification of potential visual mitigation measures. These may take the form of adopting alternative designs or revisions to the basic engineering and architectural design to prevent and/or minimise adverse impacts; remedial measures such as colour and finishing treatment of building features; and compensatory measures such as the implementation of landscape design measures (e.g. tree planting, creation of new open space etc.) to compensate for unavoidable adverse impacts and to attempt to generate potentially beneficial long term impacts. A programme for the mitigation measures shall be provided. The agencies responsible for the funding, implementation, management and maintenance of the mitigation measures shall be identified and their approval-in-principle shall be sought.

(xi) Prediction of the significance of visual impacts before and after the implementation of the mitigation measures. By synthesising the magnitude of the various visual changes and the sensitivity of the VSR, and the number of individuals in the VSR that are affected, it is possible to categorise the degree of significance of the impacts in a logical, well-reasoned and consistent fashion.

Table 8.1 shows the rationale for dividing the degree of significance into four thresholds, namely, insubstantial, slight, moderate and substantial, depending on the combination of a negligible / small / intermediate / large magnitude of change and a low / medium / high degree of sensitivity of VSRs. Consideration is also given to the relative numbers of individuals in the VSRs in predicting the final impact significance - exceptionally low or high numbers of individuals in a VSR may change the result that might otherwise be concluded from a consideration of the type of the VSRs alone.

Table 8.1 The significance of the visual impacts is categorised as follows:

Substantial:	Adverse / beneficial impact where the proposal would cause significant deterioration or improvement in existing visual quality perceived by the general population;
Moderate:	Adverse / beneficial impact where the proposal would cause a noticeable deterioration or improvement in existing visual quality perceived by the general population;
Slight:	Adverse / beneficial impact where the proposal would cause a barely perceptible deterioration or improvement in existing visual quality perceived by the general population;
Insubstantial:	No discernible change in the existing visual quality perceived by the general population;
None	Absolutely no change in the existing visual quality perceived by the general population.

(xii) Prediction of Acceptability of Residual Impacts. An overall assessment of the acceptability or otherwise of the residual impacts 10 to 15 years after implementation of visual mitigation measures, according to the five criteria set out in Annex 10 of the EIAO TM is provided.

8.4.4 Other Considerations

(i) In accordance with EIAO Guidance Note 8/2010 (paragraph 3.7(a)) approved projects should form part of the baseline conditions. Therefore, the landscape and visual outcomes (including proposed landscape and visual mitigation measures) of approved projects currently under construction, should be included as part of the baseline. Details of relevant concurrent projects are provided in Section 8.5.2.

(ii) All mitigation proposals in the EIA report shall be practical and achievable within the known parameters of funding, implementation, management and maintenance. The suggested agents for the funding and implementation (and subsequent management and maintenance, if applicable) are indicated in the EIA report. Approvals-in-principle to the implementation, management and maintenance of the proposed mitigation measures in Tables 8.6 and 8.7 have been sought and obtained from the appropriate authorities.

8.4.5 Photomontages

(i) Representative views from various locations have been selected to illustrate the effectiveness of the proposed impact mitigation proposals and residual impacts of the development in both the short and long term. Photomontages illustrating the proposed works and the recommended mitigation measures are listed in Section 8.7.4. The locations of the selected viewpoints are indicated on Figure 8.7.2 with the views and photomontages illustrated on Figures 8.12.1 to 8.16. The photomontages illustrate the proposed development under the following scenarios:

· Existing Baseline Conditions;

· Day 1 of completed works without mitigation measures;

· Day 1 of the completed works with mitigation measures; and

· The completed works with mitigation after 10 years.

8.5 Baseline Conditions

8.5.1 Landscape Study Area

The landscape impact study area is 500m from the works boundary surrounding the existing Wang Tong River Bridge and is illustrated on Figure 8.1. To the north the Study Area includes Silver Mine Bay Beach, the flat lowland Wang Tong valley and the coastal upland hills which form part of the Lantau North Country Park Extension. To the east, the Study Area includes the sea area of Silver Mine Bay. To the south lies the peripheral residential areas of Mui Wo and to the west lies Chung Hau, Ling Tsui Tau and the vegetated Butterfly Hill.

8.5.2 Committed and Approved Projects under Construction

In accordance with EIAO Guidance Note 8/2010 (paragraph 3.7(a)) approved projects to be completed before commencement of this project, should form part of the baseline conditions. The following approved projects have been identified within the vicinity of the project site.

(a) Improvement Works at Mui Wo: Following public consultation and a feasibility study to enhance the environment and attractiveness of Mui Wo and explore the recreational potential of Mui Wo, the Islands District Council endorsed the implementation of a number of improvement works. CEDD is implementing the works by phases in the town centre of Mui Wo, particularly from the ferry pier leading to Silvermine Bay Beach. Phase 1 of the works started in July 2014 with a target completion date of 2016. The current works do not have a direct interface with the New Wang Tong River Bridge.

(b) Improvement Works at Silvermine Bay Beach: The Islands District Council proposes to undertake improvement works under the Signature Projects Scheme to rejuvenate Silvermine Bay Beach and achieve synergy with the CEDD project. The proposed works include:

· Demolition of the existing beach service buildings;

· Construction of new beach buildings and associated beach facilities;

· Construction of new barbeque pit area and sitting-out area; and

· Construction of a viewing deck near the entrance to the beach.

A plan of the proposed improvement works is provided in Appendix 8B. The works are intended to commence in January 2016 and be completed in 2018 (as per programme stated in Legco Paper, however the latest programme from the Project Architect is completion on 1 January 2017). The project will adopt a modern design for the beach facilities and buildings. There is no direct interface between the proposals and those of the New Wang Tong River Bridge and there appears to be no conflict in the proposed preliminary design for the New Wang Tong River Bridge which also adopts a contemporary style. However, any unforeseen interface requirements can be addressed at the Detail Design Stage of the project.

(c) Contract No. DC/2012/02 – Upgrading of Mui Wo Sewage Treatment Works and Village Sewerage at Wang Tong and Yue Kwong Tsuen: these DSD works include the construction of a section of sewer in the vicinity of the existing Wang Tong River Bridge. These works are substantially complete and reinstatement of road, cycle track and footpath surfaces is anticipated to be completed before commencement of the New Wang Tong River Bridge construction works.

8.5.3 Review of Current Land Uses

A review of the current land-uses within the study area is provided below. The existing LRs and LCAs within the study area have been identified and are described in Sections 8.5.4 and 8.5.5. The sensitivities of the LRs and LCAs have been summarised in Table 8.2 and Table 8.3.

(i) The study area lies within Mui Wo Layout Plan No. L/I-MWN/IB and L/I-MWC/1F. The land use planning control of the Ferry Pier Area, Mui Wo Town Centre and Silver Mine Bay Beach waterfront area etc. are governed by the above mentioned Layout Plans.

(ii) The western edge of the study area falls within the Mui Wo Fringe Outline Zoning Plan (OZP) No. S/I – MWF/10, an extract of which is shown on Figure 8.2.

(iii) The objective of the plan is to specify the broad land use zonings and major transport network so that any development will be under statutory planning control.

(iv) The following land use zonings fall within the western edge of the Study Boundary and the planning intention is described below:

· Agriculture (“AGR”): This zoning is intended to retain and safeguard good quality existing agricultural land/farm/fish ponds for agricultural purposes and fallow arable land with good potential for rehabilitation for cultivation and other agricultural purposes.

· Open Space (“O”): the planning intention of this zone is to provide outdoor open-air space for active and/or passive recreation uses serving the needs of local residents as well as the general public.

· Residential (Group A) “R(A)”: this zone is primarily intended for medium density residential developments. Commercial uses are always permitted on the ground floor of a building or in the purpose-designed non-residential portion of an existing building.

· Green Belt (“GB”): This zone is intended primarily to define the limits of urban and sub-urban development areas by natural features and to protect natural landscape as well as to provide passive recreational outlets for local population and visitors. There is a general presumption against development within this zone.

· Government, Institution or Community (G/IC”): This zone is intended primarily for the provision of government, institution or community facilities serving the needs of the local residents and a wider district. It is also intended to provide land for uses directly related to or in support of the work of the government organisations providing social services to meet community needs, and other institutional establishments.

· Recreation (“REC”): This zone is intended primarily for the use of the general public. It encourages the development of active and/or passive recreation and tourism/eco-tourism. Uses in support of the recreational developments may be permitted subject to planning permission.

Designated Country Park

Lantau Country Park lies to the west of Mui Wo and the limit of the Mui Wo Fringe OZP No. S/I – MWF/10. The Lantau North (Eastern Extension) Country Park eastern extension encompasses the vegetated hills to the north and east. The proposed project does not physically impact either of the Country Park areas.

Bridge Environs

The northern edge of the built-up area of Mui Wo is delineated by the Wang Tong River and this marks the transition to smaller scale village type development, flat river valley and beach frontage. The existing Wang Tong River Bridge spans the Wang Tong River where it meets Silver Mine Bay Beach. The Large Silver Mine Bay Beach Resort Hotel and a formal tree lined beach promenade lies to the south and village type development lies to the west with the steep, densely vegetated slopes of Butterfly Hill behind. To the north, semi natural lowland vegetation (former agricultural land) lies behind the beach with the village of Wang Tong beyond. The bridge connects the promenade to the south with Silver Mine Bay Beach to the north which forms a broad sandy crescent curving to the north east. The back of the beach is defined by a recently upgraded promenade which is used by unsegregated pedestrians, cyclists and small village powered vehicles. A mixture of residential, commercial and municipal buildings lie behind the promenade including small shops, hotels, life guard and public beach changing facilities. Silver Mine Bay lies to the east.

Conclusion

The proposed project is for the replacement and upgrading of an existing community facility, and it is therefore considered that there is no conflict with the relevant planning and development control framework, as it is consistent with the planning intention of “Footbridge” as stipulated on Mui Wo Layout Plan No. L/I-MWN/1B.

8.5.4 Landscape Resources (LRs)

(i) The baseline LRs that fall within the landscape impact study area during the construction phase and operation phase, together with their sensitivity to change, are described below and tabulated in Table 8.2. The locations of the LRs are mapped on Figure No. 8.3. Photo-views illustrating the LRs within the study area are illustrated on Figure No. 8.4.1 to 8.4.5. For ease of reference and co-ordination between text, tables and drawings, each LR is given an identity number. Roads and pavement are not considered as Landscape Resources and have not been included in the mapping of resources. Figure No. 8.3 attempts to formalize boundaries between distinct areas of Landscape Resources for the purpose of impact assessment, and should not be construed as reflecting every variable on the ground.

LR1 –Coastal Waters

(ii) This landscape resource consists of the sea area within the enclosed tidal bay of Silver Mine Bay. The approximate area is 28 ha. Given the uniqueness of the bay marine environment, the scenic value and the resource’s low tolerance to change, the sensitivity is assessed as High.

LR2a – Wang Tong River

(iii) The Wang Tong River flows though the Study Area from the north west to south east, passing under the existing Wang Tong Bridge and continuing across Silver Mine Bay Beach to the sea. The River is shallow and non-navigable, and the lower reaches are tidal. Although it flows through the agricultural Wang Tong Valley, the river channel is largely natural and provides a habitat and breeding ground for avifauna and fish (refer to Ecological Assessment chapter). The approximate length within the study area is 700 m. The northern bank is lined with small trees and shrubs, primarily Hibiscus tiliaceus with smaller numbers of Ficus subpisocarpa, Litsea glutinosa, Macaranga tanarius var. tomentosa, Melia azardarach, Pandanus tectorius, Syzygium samaragense and Wedelia trilobata. Mangrove species (Aegiceras corniculatum and Acanthus ilicifolius) are also found in the River. Whilst the value of the ecological habitats within this resource have been rated as low, given that natural rivers are under threat and a disappearing resource in Hong Kong and that this resource is difficult to recreate the sensitivity is assessed as High.

LR2b – River Silver

(iv) The River Silver flows from the west through the town area of Ling Tsui Tau until it meets the sea of Silver Mine Bay. The river has been largely channelized with engineered banks to control flooding and the lower reaches have been widened to create a broad, sheltered navigable mooring area for fishing and pleasure boats. The approximate length of the River Silver is 800m. Whilst the river is an attractive and well-used resource, given the high degree of intervention along this channel, the tolerance to further change is considered high and the sensitivity is assessed as Medium.

LR4 – Upland Streams

(v) Several upland streams drain off the natural vegetated slopes in the north of the Study Area and into the Wang Tong River. They have a combined approximate length of 850m. Given their scenic and ecological value and low tolerance to change their sensitivity is assessed as High.

LR5 – Natural Rocky Coastline

(vi) The coast within the study Area consists largely of engineered stone-clad revetments and natural sandy shoreline. There is an outcrop of natural granite at the northern end of Silver Mine Bay Beach which forms an attractive small headland. The approximate area is 530 sq.m. Given its scenic value and that this is the only remaining natural rocky coast within the Study Area, the sensitivity is assessed as High.

LR6 – Silver Mine Bay Beach

(vii) Silver Mine Bay Beach stretches from the River Silver in the south all the way to the northern corner of Silver Mine Bay and is a popular, highly used recreational resource. The sand is clean and fine and an ideal surface for relaxation and recreation. In addition, it provides a valuable marine habitat for flora and fauna. Floral species include Casuarina equisitifolia, Hibiscus tiliaceus, Ipomoea pes-caprae, Macaranga tanarius var. tormentosa, Terminalia catappa and Wedelia trilobata. The approximate area within the Study Boundary is 1.6 ha. Given that this resource is both a valuable ecosystem has a heavily-used recreational venue and cannot be replaced, the sensitivity is assessed as High.

LR7– Natural Upland Vegetation

(viii) The natural slopes of the surrounding hills support scrubby woodland vegetation. The area within the Study Boundary is approximately 30 ha. Species composition varies greatly and is primarily native with some exotic species and includes Celtis sinensis, Ficus spp., Schefflera heptaphylla forming the canopy with Daphniphyllum calycinum, Ilex asprella and Litsea rotundifolia var. oblongifolia found in the understory. The rare and precious plant Aquilaria sinensis was identified in woodland area by the ecological survey. However overall, given that this resource is relatively common and widespread and can be regenerated, the sensitivity is assessed as Medium.

LR8 - Semi-Natural Lowland Vegetation

(ix) The Wang Tong River Valley is an area of abandoned agricultural land and now supports areas of regenerated marsh (species including Acrostichum aureum, Cyperus involucratus), grassland/shrubland (Melastoma sanguneum, Mikania micrantha) and woodland habitats (Hibiscus tiliaceus, Microcos nervosa, Tarenna attenuata). Herb species include Azolla imbricata, Ludwigia spp. and Zingiber officinale. The approximate area is 6.9ha. Given its relatively disturbed nature and that the ecological assessment of value is generally low for the habitats within this Landscape Resource, the sensitivity is assessed as Medium.

LR9 - Urban/Domestic Amenity Planting

(x) The urban and village areas of Mui Wo include approximately 5ha of amenity planting including trees and shrubs planted by local councils on government land and/or private individuals in private lots. Tree and shrub species include typical street and park species including Aglaia odorata var. microphyllina, Araucaria heterophlylla, Archontophoenix alexandrae, Bauhinia blakeana, Dimocarpus longan, Duranta erecta, Dypsis lutescens, Ficus microcarpa, Hibiscus tileaceus, Lagerstroemia speciosa, Mangifera indica, Playcladus orientalis, Rhododendron pulchrum, Rhododendron simsii, Terminalia catappa, Roystonea regia. Two trees within this area are listed as Old and Valuable Trees on the LCSD OVT Register: LCSD IS/2 – Casuarina equisetifolia (in the barbecue pits on the Silvermine Bay Beach promenade); LCSD IS/3 – Ficus microcarpa (on Chung Hau Street). Neither of these trees will be impacted. Whilst this planting contributes directly to the amenity of the town and village areas, it is generally exotic and non-native and does not generally consist of rare or precious species (OVTs exempted) and is replaceable. It is therefore assessed as having Medium sensitivity.

LR10 - Existing Trees in Vicinity of Wang Tong River Bridge

(xi) There are a number of existing trees in the immediate vicinity of the Wang Tong River Bridge growing either in the waterfront paved areas or Silver Mine Bay Beach. As they may be potentially impacted, a detailed tree survey has been undertaken in accordance with DEVB TC(W) 7/2015 (refer Appendix 8A). Surveyed trees total 19 no. and comprise the following species Casuarina equisetifolia, Celtis sinensis, Ficus microcarpa, Hibiscus tiliaceus, Macaranga tanarius, Terminalia catappa. Whilst the trees are neither registered Old and Valuable Trees nor rare or precious species, the trees are mature and do contribute to the immediate setting of the bridge and provide a positive visual backdrop to the back of the beach. Their health and amenity value is generally Fair to Good and their overall sensitivity is assessed as Medium.

Table 8.2: Landscape Resources

Ref. ID.	Description	Sensitivity to Change (Low, Medium, High)
LR1	Coastal waters Baseline: approx. 28ha	High
LR2a	Wang Tong River Baseline: approx.700 m	High
LR2b	River Silver Baseline: approx. 800m	Medium
LR4	Upland Streams Baseline: approx. 850m	High
LR5	Natural Rocky Coastline Baseline: approx. 530 m	High
LR6	Silvermine Bay Beach Baseline: approx. 1.6ha	High
LR7	Natural Upland Vegetation Baseline: approx. 30 ha	Medium
LR8	Semi-Natural Lowland Vegetation Baseline:: approx. 6.9ha	Medium
LR9	Urban/Domestic Amenity Tree & Shrub Planting Baseline: approx. 5 ha	Medium
LR10	Existing Trees in vicinity of Wang Tong Bridge Baseline: 19 No.	Medium

8.5.5 Landscape Character Areas (LCAs)

Several LCAs have been identified within the study area with reference to the ‘Landscape Value Map of Hong Kong’ and refined with reference to existing conditions. These areas, and their sensitivity to change, are described below and tabulated in Table 8.3. The locations of the LCAs are indicated on Figure 8.5. Photographic views illustrating the LCAs within the study area are illustrated on Figure 8.6. For ease of reference and co-ordination between text, tables and drawings each LCA is given an identity number. The below listed LCA’s represent the baseline condition after completion of the approved committed projects.

LCA1 – Coastal Upland and Hillside Landscape

(i) This area is characterised by steeply sloping vegetated slopes comprising a mixture of woodland and scrub. Its approximate area is 28.9 ha. The northern portion of this LCA lies outside but on the fringe of the Lantau North (Extension) Country Park, the western portion covers Butterfly Hill and has no statutory protection and the southern portion lies in Greenbelt which has a general presumption against development (refer Section 8.5.3 (iv), 4^th bullet) above. The LCA is a mature, relatively undisturbed environment where vegetation, primarily native species, has naturally colonised and therefore has a low tolerance to change. This landscape character is relatively common on Lantau but in the local context of the urban area of Mui Wo, its preservation is important as the vegetated hills and slopes form a green backdrop to Mui Wo and provide a degree of enclosure that enhances the setting and preserves the rural fringe character of the town. Given its relatively natural condition and low tolerance of change, the sensitivity is of this LCA is assessed as High.

LCA2- Bay Landscape

(ii) This LCA comprises part of the open water of Silver Mine Bay and the bay edge including Silver Mine Bay Beach. Its approximate area is 29.7 ha. Bay landscape is common on the south side of Lantau but is under increasing pressure from development. Its value is recognised by recent government initiatives to promote leisure and tourism on South Lantau. The waters and beach forming this LCA are relatively natural and undisturbed and of high environmental and scenic quality. The bay waters are highly frequented by leisure and fishing craft and swimmers and the beach is a popular public facility. As its landscape value lies in its intrinsic natural beauty, this LCA has a low ability to accommodate change. Given all the factors above, the sensitivity of LCA2 is assessed as High.

LCA3 – Rural Township Landscape

(iii) This LCA comprises the collection of villages and the urban areas that make up Mui Wo and is approximately 25.4 ha in area. It occupies the flat land between the wooded knoll in the south of the Study Area and Butterfly Hill in the west. The LCA also stretches along the back of Silver Mine Bay Beach and includes a strip of hotels, small shops, public beach facilities and private residences. The settlement of Mui Wo has developed relatively slowly and remained at a rural township scale due to the lack of easy access by road. The scale of the residential buildings is generally small and restricted to 3 storeys or less and there are a number of larger municipal and commercial buildings and hotels. The style and type of development is unremarkable and commonly found throughout the urban fringes of Hong Kong. Whilst the overall scene has a certain attractiveness (due largely to the natural setting), the visual and historic quality of the individual structures is generally low. This LCA has a reasonable tolerance to change as it is in a constant cycle of renewal as evidenced by recent Government improvement works. Given the above, the sensitivity of this LCA is assessed as Medium.

LCA4 – Settled Valley Landscape

(iv) This LCA comprises the flat floor of the Wang Tong River Valley and includes Wang Tong River, both active and abandoned agricultural fields, marsh, grassland/shrubland, lowland woodland areas and village type settlements. Its approximate area is 10.2 ha. It lies on the fringes of the Lantau North (Extension) Country Park and Greenbelt areas of Mui Wo. This LCA has an attractive outlook due to the overall greenness and small scale of development (primarily village houses of maximum 3 storeys) which imparts a relaxed, rural atmosphere. The area has evolved relatively slowly although the size of Wang Tong village has increased in the last 10 to 20 years as demand for rural fringe lifestyle has increased. The built character of the village areas is unremarkable and representative of post war rural village development throughout Hong Kong. The vegetated portion of this LCA comprises cultivated and abandoned land supporting a mixture of native and exotic species. Overall, the scenic quality of this LCA is high and it contributes to the general attractiveness of the Mui Wo locality. It is viewed from public footpaths passing through it and on the surrounding hills. Due to the mixture of land-uses and on-going piecemeal development this LCA has a reasonable tolerance to change and the sensitivity is assessed as Medium.

Table 8.3: Landscape Character Areas

Ref. ID.	Description	Sensitivity to Change (Low, Medium, High)
LCA1	Coastal Upland and Hillside Landscape Baseline: 28.9 ha	High
LCA2	Bay Landscape Baseline: 29.7 ha	High
LCA3	Rural Township Baseline: 25.4 ha	Medium
LCA4	Settled Valley Baseline: 10.2 ha	Medium

8.5.6 Visual Study Area/Zone of Visual Influence (ZVI)

(i) The Key Visual Elements of the visual study area have been mapped on Figure 8.7.1. Silver Mine Bay is a large seawater bay enclosed by steeply rising topography to the north and south. The ridge lines of the vegetated hills provide a dramatic backdrop to the bay. Silver Mine Bay Beach forms the western edge of the bay. The bay overlooks Hei Ling Chau to the east. The key built-up areas and settlements that contribute to the visual context include Mui Wo Town Centre to the south of the project site and the village settlements of Chung Hau, Wang Tong and Tung Wan Tau to the west, north and north east respectively. The proposed project site is at the back of Silver Mine Bay Beach on the edge of the urban area of Mui Wo. Key view points within the study area are identified on Figure 8.7.1. These include:

· Views from inter-island ferries and recreational craft within Silver Mine Bay;

· Views from the Mui Wo Waterfront from the ferry pier to the River Silver;

· Views from Silver Mine Bay Beach;

· Views from Tung Wan Tau south across Silver Mine Bay;

· Elevated views from hiking trails from Mui Wo to the Trappist Monastery and Discovery Bay south across Silver Mine Bay.

(ii) The ZVI for the Construction and Operation Phases of the project has been mapped based on the exposure of the proposed development to the surrounding environment and is illustrated on Figure 8.7.2. In accordance with EIAO GN 8/2010 the ZVI may contain areas which are fully visible, partly visible, and non-visible from the project. Areas of visual shadow may occur within the ZVI due to intervening topography, dense vegetation and man-made structures.

(iii) The ZVI during the Construction and Operation Phases will be the same. The bridge is a low structure and views of it are predominantly from the east across the unobstructed expanse of the bay. To the west, the bridge is largely screened by exiting trees at the back of Silver Mine Bay Beach and the buildings forming Silver Mine Bay Hotel.

(iv) To the west the ZVI is demarcated by the buildings and trees at the back of Silver Mine Bay Beach. There is a limited view corridor up the Wang Tong River but access is limited to the south bank of the river along a road with footpath. There will be Views from the upper storeys of the Silver Mine Bay Hotel but these are largely screened out by a large existing tree on the hotel boundary. The north bank is heavily wooded and unoccupied. Some dwellings on the rising slopes of Butterfly Hill to the west may have views down the river corridor to the bridge. Views from the hills to the west are screened out by the heavily wooded Butterfly Hill, existing trees and the Silver Mine Bay Hotel along the back of Silver Mine Bay Beach (refer photos of views from the hills to the west of Silver Mine Bay Beach on Figure 8.8.3 which indicate that the bridge cannot be seen from the west due to topographic and existing tree screens).

(v) To the north, the ZVI follows the residences at Tung Wan Tau and is punctuated by viewpoints from the elevated footpath leading to the Trappist Monastery and Discovery Bay. Trees on the natural slopes to the north prevent views from much of the footpath. There are several isolated residences along the northern coast of Silver Mine Bay with views to the south west towards the bridge. However, apart from these, viewpoints from above coast level are largely blocked by dense woodland alongside footpaths.

(vi) To the east, the ZVI is defined by the western coast of Hei Ling Chau. Staff and inmates at the Addiction Treatment Centre will have distant views north west towards Silver Mine Bay. The typhoon shelter breakwater defines the ZVI edge to the south of the island.

(vii) To the south of the Wang Tong River Bridge, the ZVI is defined by the Silver Mine Bay Hotel and the waterfront from the River Silver to the Mui Wo Ferry Pier.

8.5.7 Visually Sensitive Receivers (VSRs)

(i) Within the ZVI, a number of key VSRs have been identified. These VSRs are mapped on Figure No. 8.7.2 and are listed in Table 8.4.

(ii) For ease of reference, each VSR is given an identity number, which is used in the text, tables and drawings.

[1] Pastorok, R.A. and Bilyard, G.R. (1985). “Effects of sewage pollution on coral-reef communities.” Marine Ecology Progress Series 21: 175-189.

[2] Hawker, D. W. and Connell, D. W. (1992). “Standards and Criteria for Pollution Control in Coral Reef Areas” in Connell, D. W and Hawker, D. W. (eds.), Pollution in Tropical Aquatic Systems, CRC Press, Inc.

[3] EPD. 2012. Marine Water Quality in Hong Kong in 2011. [online] http://wqrc.epd.gov.hk/pdf/water-quality/annual-report/Marine2011EN.pdf . Accessed: 17 May 2016.

[4] EPD. 2013. Marine Water Quality in Hong Kong in 2012. [online]

http://wqrc.epd.gov.hk/pdf/water-quality/annual-report/Report2012eng.pdf. Accessed: 17 May 2016.

[5] Mott MacDonald. 2010. South Island Line (East) Ch. 5 Water Quality. [online] Available at: http://www.epd.gov.hk/eia/register/report/eiareport/eia_1852010/EIA/PDF/Text/Rev%20F_Sec%205.pdf. Last accessed: 17 May 2016.

ID No.	Landscape Resources/ Landscape Character Areas	Source of Impact	Description of Impacts	Magnitude of Change before Mitigation
LR1	Coastal Waters	Construction - Removal of the existing bridge pier.	Construction - Minimal amounts of sediment from the dredging works to remove the existing bridge pier	Small
LR1	Coastal Waters	Operation - None	Operation - None	None
LR2a	Wang Tong River	Construction - Removal of the existing bridge pier.	Construction - Minimal amounts of sediment from the dredging works to remove the existing bridge pier	Small
LR2a	Wang Tong River	Operation - None	Operation - None	None
LR2b	River Silver	Construction - None	Construction - None	None
LR2b	River Silver	Operation - None	Operation - None	None
LR4	Upland Streams	Construction - None	Construction - None	None
LR4	Upland Streams	Operation - None	Operation - None	None
LR5	Natural Rocky Coastline	Construction - -None	Construction - None	None
LR5	Natural Rocky Coastline	Operation - -None	Operation - None	None
LR6	Silver Mine Bay Beach	Construction - Bridge and ramp demolitions works and modification of existing waterfronts; - Stockpiling of materials for construction of new bridge; - Dust and construction debris; - Construction of on-site offices and working areas; and - Presence of temporary construction hoardings, plant, platforms, structures, construction machinery and construction vehicle traffic.	Construction - Temporary loss of beach areas (approximately 950 sq.m) due to presence of temporary construction hoardings, plant, platforms, structures, construction machinery and construction vehicle traffic. - Baseline area: 1.6 ha	Small
LR6	Silver Mine Bay Beach	Operation - New twin bridges	Operation - Additional footprint of new twin bridges (approximately 300 sq.m) - Baseline area: 1.6ha	Negligible
LR7	Natural Upland Vegetation	Construction - None	Construction - None	None
LR7	Natural Upland Vegetation	Operation - None	Operation - None	None
LR8	Semi-natural Lowland Vegetation	Construction - None	Construction - None	None
LR8	Semi-natural Lowland Vegetation	Operation - None	Operation - None	None
LR9	Urban/Domestic Amenity Planting	Construction - None	Construction - None	None
LR9	Urban/Domestic Amenity Planting	Operation - None	Operation - None	None
LR10	Existing Trees in Vicinity of Wang Tong Bridge	Construction - Bridge and ramp demolitions works and modification of existing waterfronts	Construction - Felling of 5 no. existing trees - Transplanting of 2 no. existing trees - Baseline no: 19	Intermediate
LR10	Existing Trees in Vicinity of Wang Tong Bridge	Operation - Footprint of new twin bridges	Operation - Absence of 5 no. existing trees - Baseline no: 19	Intermediate
LCA1	Coastal Upland and Hillside Landscape	Construction - None	Construction - None	None
LCA1	Coastal Upland and Hillside Landscape	Operation - None	Operation - None	None
LCA2	Bay Landscape	Construction - Bridge and ramp demolitions works and modification of existing waterfronts; - Stockpiling of materials for construction of new bridge; - Dust and construction debris; - Construction of on-site offices and working areas; and - Presence of temporary construction hoardings, plant, platforms, structures, construction machinery and construction vehicle traffic.	Construction - Temporary loss of beach area (approximately 950 sq.m) - Baseline area: 29.7 ha	Small
LCA2	Bay Landscape	Operation - New twin bridges	Operation - Footprint of new twin bridges (approximately 300 sq.m) - Baseline area: 29.7 ha	Negligible
LCA3	Rural Township	Construction - Bridge and ramp demolitions works and modification of existing waterfronts; - Stockpiling of materials for construction of new bridge; - Dust and construction debris; - Temporary traffic management; - Construction of on-site offices and working areas; and - Presence of temporary construction hoardings, plant, platforms, structures, construction machinery and construction vehicle traffic.	Construction - Temporary loss of area (approximately 260 sq.m) - Baseline area: 25.4 ha	Small
LCA3	Rural Township	Operation - New twin bridges	Operation - Additional footprint of new twin bridges (approximately 95 sq.m) - Baseline area: 25.4ha	Negligible
LCA4	Settled Valley Landscape	- None	Construction - None	None
LCA4	Settled Valley Landscape	- None	Operation - None	None

ID No.	Landscape and Visual Mitigation Measure	Landscape measure	Visual measure	Funding Agency	Implementation Agency
CM1	The construction area and contractor’s temporary works areas should be minimised to avoid impacts on adjacent landscape.	✓	✓	HyD	Contractor
CM2	Reduction of construction period to practical minimum.		✓	HyD	Contractor
CM3	Construction traffic (land and sea) including construction plant, construction vessels and barges should be kept to a practical minimum.		✓	HyD	Contractor
CM4	Erection of decorative mesh screens or construction hoardings around works areas in visually unobtrusive colours.		✓	HyD	Contractor
CM5	Avoidance of excessive height and bulk of site buildings and structures.		✓	HyD	Contractor
CM6	Control of night-time lighting by hooding all lights and through minimisation of night working periods.		✓	HyD	Contractor
CM7	All existing trees shall be carefully protected before, during construction and after construction. A Detailed Tree Protection Specification shall be provided in the Contract Specification. Under this specification, the Contractor shall be required to submit a detailed working method statement for the protection of trees prior to undertaking any works adjacent to all retained trees or trees to be transplanted, including trees in contractor’s works areas for approval by the Registered Landscape Architect (RLA). This method statement for tree protection and transplanting shall make reference to "Guidelines on Tree Preservation during Construction" and "Guidelines on Tree Transplanting" published by GLTM of the DEVB. Early preparation of trees to be transplanted shall be undertaken to increase their likely survival rate following transplanting.	✓		HyD	Contractor
CM8	Minimisation of Impacts to Wang Tong River through minimised and carefully controlled dredging for pile/abutment removal/construction works	✓		HyD	Contractor

ID No.	Landscape and Visual Mitigation Measure	Landscape Measure	Visual Measure	Funding Agency	Implementation Agency	Management Agency	Maintenance Agency
OM1	Sensitive design of bridge in terms of scale, height and bulk (visual weight).		✓	HyD	Design Architect/ Engineer	HyD	HyD
OM2	Use of appropriate building materials and colours for bridge to complement surroundings.		✓	HyD	Design Architect/ Engineer	HyD	HyD
OM3	Lighting units to be directional and minimise unnecessary light spill and glare.		✓	HyD	Design Architect/ Engineer	HyD	HyD
OM4	Integration of bridge with existing abutments and promenades.		✓	HyD	Design Architect/ Engineer	HyD	HyD
OM5	Compensatory tree planting for all felled trees shall be provided to the satisfaction of relevant Government departments. Required numbers and locations of compensatory trees shall be determined and agreed separately with Government during the Tree Felling Application process under the relevant technical circulars.	✓	✓	HyD	Contractor	HyD, until such time the trees are successfully handed over to LCSD	HyD, until such time the trees are successfully handed over to LCSD
OM6	Streetscape (e.g. paving, signage, street furniture, lighting etc.) shall be sensitively designed in a manner that responds to the existing village context, and minimises potential adverse landscape and visual impacts.	✓	✓	HyD	Design Architect/ Engineer	HyD	HyD

VSR ID.	Key VSR	Value and Quality of Existing View (Poor, Fair , Good)		Availability of Alternative Views (Yes, No)	Number of Individuals (Very Few, Many, Very Many)			Sensitivity to Change (Low, Medium, High)
					Construction	Operation		Construction	Operation
Residential VSRs
RES-1	Residents in Chung Hau		Good	Yes	Few		Few	High		High
RES -2	Residents at Tung Wan Tau		Good	Yes	Few		Few	High		High
RES-3	Inmates at Hei Ling Chau Addiction Treatment Centre		Good	Yes	Few		Few	Medium		Medium
RES-4	Residents along North-East Coast of Silver Mine Bay		Good	Yes	Few		Few	High		High
Recreational VSRs
REC-1	Users of Silver Mine Bay Beach		Good	Yes	Very Many		Very Many	High		High
REC-2	Hikers on Footpath to Trappist Monastery		Good	Yes	Many		Many	High		High
REC-3	Users of Silver Mine Bay waterfront		Good	Yes	Very Many		Very Many	High		High
REC-4	Guests at Silver Mine Bay Beach Hotel (north Block)		Good	Yes	Few		Few	Medium		Medium
REC-5	Recreational Craft in Silver Mine Bay		Good	Yes	Few		Few	High		High
REC6	Visitors to Seafood Restaurants along Silver Mine Bay Waterfront		Good	Yes	Many		Many	Low		Low
Travelling VSRs
T-1	Passengers on Inter-Island Ferries		Good	Yes	Very Many		Very Many	Low		Low
T-2	Drivers/Passengers along Ngan Kwong Wan Road		Good	Yes	Very Many		Very Many	Medium		Medium
T-3	Drivers, Cyclists and Pedestrians along Tung Wan Tau Road		Good	Yes	Very Many		Very Many	Medium		Medium
Occupational VSRs
O-1	Workers in Seafood Restaurants along Silver Mine Bay Waterfront		Good	Yes	Few		Few	Low		Low
O2	Fishermen in Silver Mine Bay		Good	Yes	Few		Few	Low		Low
O3	Workers in Commercial Outlets along Silver Mine Bay Beach		Good	Yes	Few		Few	Low		Low
Note: ‘Duration and Frequency of Views’ and ‘Degree of Visibility’ have been taken into account in assessing the magnitude of change in view experience by the VSRs and cannot be double counted in determining the sensitivity of the VSR.

Id. No.	Landscape Resource / Landscape Character	Sensitivity to Change during Construction and Operation Phases (Low, Medium, High)	Magnitude of Change before Mitigation (None, Negligible, Small, Intermediate, Large)		Impact Significance Threshold BEFORE Mitigation (None, Insubstantial, Slight, Moderate, Substantial)					Recommended Mitigation Measures	Residual Impact Significance Threshold AFTER Mitigation (None, Insubstantial, Slight, Moderate, Substantial)
											Construction	Operation
			Construction	Operation	Construction		Operation				Construction	DAY 1	YEAR 10
Landscape Resources
LR1	Coastal Waters	High	Small	None	Slight	None		CM1,8			Insubstantial	None	None
LR2a	Wang Tong River	High	Small	None	Slight	None		CM1,8			Insubstantial	None	None
LR2b	River Silver	Medium	None	None	None	None		N/A			None	None	None
LR4	Upland Streams	High	None	None	None	None		N/A			None	None	None
LR5	Natural Rocky Coastline	High	None	None	None	None		N/A			None	None	None
LR6	Silver Mine Bay Beach	High	Small	Negligible	Slight	Insubstantial		CM1,7 OM5			Slight	Insubstantial	Insubstantial
LR7	Natural Upland Vegetation	Medium	None	None	None	None		N/A			None	None	None
LR8	Semi-natural Lowland Vegetation	Medium	None	None	None	None		N/A			None	None	None
LR9	Urban/Domestic Amenity Planting	Medium	None	None	None	None		N/A			None	None	None
LR10	Existing Trees in vicinity of Wang Tong River Bridge	Medium	Intermediate	Intermediate	Moderate	Moderate		CM1, 7 OM5			Moderate	Slight	Insubstantial
Landscape Character Areas
LCA1	Coastal Upland and Hillside Landscape	High	None	None	None	None			N/A		None	None	None
LCA2	Bay Landscape	High	Small	Negligible	Slight	Insubstantial			CM1,7,8 OM5		Insubstantial	Insubstantial	Insubstantial
LCA3	Rural Township Landscape	Medium	Small	Negligible	Slight	Insubstantial			CM1,7,8 OM6		Insubstantial	Insubstantial	Insubstantial
LCA4	Settled Valley Landscape	Medium	None	None	None	None			N/A		None	None	None

VSR ID	Key VSR	Compatibility of the Project with the Visual Backdrop (High/Medium/Low)	Duration and Frequency of Impacts (Temporary/Permanent & Intermittent/Continuous)		Scale of Development (Large/Medium/Small) & Reversibility of Change (Yes/No)	Degree of Visibility of Source(s) of Visual Impact (Full, Partial, Obscured) & Distance Between VSR & Nearest Source(s) of Impact		Potential Blockage of Existing View (Full/Partial/Slight/Negligible)		Magnitude of Visual Change BEFORE Mitigation (Large, Intermediate, Small, Negligible, None)
VSR ID	Key VSR		Construction	Operation		Construction	Operation	Construction	Operation	Construction	Operation
Residential VSRs
RES-1	Residents in Chung Hau	Medium	Permanent, Continuous	Permanent, Continuous	Small, No	Partial, 200m	Partial, 200m	Negligible	Negligible	Intermediate	Intermediate
RES-2	Residents in Tung Wan Tau	Medium	Permanent, Continuous	Permanent, Continuous	Small, No	Full, 900m	Full, 900m	Negligible	Negligible	Negligible	Negligible
RES-3	Inmates at Hei Ling Chau Addiction Treatment Centre	Medium	Permanent, Continuous	Permanent, Continuous	Small, No	Full, 4,200m	Partial, 4,200m	Negligible	Negligible	Negligible	Negligible
RES-4	Residents along north east coast of Silver Mine Bay	Medium	Permanent, Continuous	Permanent, Continuous	Small, No	Full, 1000m	Full, 1000m	Negligible	Negligible	Negligible	Negligible
Recreational VSRs
REC-1	Users of Silver Mine Bay Beach	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full, 0m	Full, 0m	Negligible	Negligible	Large	Small
REC-2	Hikers on Footpath to Trappist Monastery	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full, 1,200m	Full, 1,200m	Negligible	Negligible	Small	Small
REC-3	Users of Silver Mine Bay Waterfront	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Partial , 400m	Partial , 400m	Negligible	Negligible	Small	Small
REC-4	Guests at Silver Mine Beach Resort Hotel (north Block)	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full , 30m	Full , 30m	Negligible	Negligible	Large	Intermediate
REC-5	Recreational Craft in Silver Mine Bay	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full , 100m	Full , 100m	Negligible	Negligible	Small	Small
REC-6	Visitors to Seafood Restaurants along Silver Mine Bay Waterfront	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Partial, 400m	Partial, 400m	Negligible	Negligible	Small	Small
Travelling VSRs
T-1	Passengers on Inter-Island Ferries	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full, 600m	Full, 600m	Negligible	Negligible	Negligible	Negligible
T-2	Drivers & Passengers along Ngan Kwong Wan Road	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Partial, 300m	Partial, 300m	Negligible	Negligible	Small	Small
T-3	Drivers, Cyclists & Pedestrians along Tung Wan Tau Road	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full, 0m	Full, 0m	Negligible	Negligible	Large	Intermediate
Occupational VSRs
O-1	Workers in Seafood Restaurants along Silver Mine Bay Waterfront	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Partial, 400m	Partial, 400m	Negligible	Negligible	Small	Small
O-2	Fishermen in Silver Mine Bay	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full, 400m	Full, 400m	Negligible	Negligible	Small	Small
O3	Workers in Commercial Outlets along Silver Mine Bay Beach	Medium	Temporary, Intermittent	Temporary, Intermittent	Small, No	Full, 10m	Full, 10m	Negligible	Negligible	Large	Large
Note:
(1) The closet viewing distance has been used to rate the worst case scenario (2) ‘Permanent’ duration measurement refers to entire construction/operation phase

VSR Type	Key Visually Sensitive Receiver (VSR)	Magnitude of Visual Change before Mitigation (None, Negligible, Small, Intermediate, Large)		Receptor Sensitivity & Number (Low, Medium, High) (Very Few, Few, Many, Very Many)		Impact Significance Threshold BEFORE Mitigation (None, Insubstantial, Slight, Moderate, Substantial)		Recommended Mitigation Measures	Residual Impact Significance Threshold AFTER Mitigation (None, Insubstantial, Slight, Moderate, Substantial)
VSR Type									Construction	Operation
& ID.		Construction	Operation	Construction	Operation	Construction	Operation		Construction	DAY 1	YEAR 10
Residential VSRs
RES-1	Residents in Chung Hau	Intermediate	Intermediate	High, Few	High, Few	Moderate	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5,6	Moderate	Slight	Slight
RES-2	Residents in Tung wan Tau	Negligible	Negligible	High, Few	High, Few	Insubstantial	Insubstantial	CM1,2,3,4,5,6 OM1,2,3,4,5	Insubstantial	Insubstantial	Insubstantial
RES-3	Inmates at Hei Ling Chau Addiction Treatment Centre	Negligible	Negligible	Medium, Few	Medium, Few	Insubstantial	Insubstantial	CM1,2,3,4,5,6 OM1,2,3,4,5	Insubstantial	Insubstantial	Insubstantial
RES-4	Residents along north east coast of Silver Mine Bay	Negligible	Negligible	High, Very Few	High, Very Few	Insubstantial	Insubstantial	CM1,2,3,4,5,6 OM1,2,3,4,5	Insubstantial	Insubstantial	Insubstantial
Recreational VSRs
REC-1	Users of Silver Mine Bay Beach	Large	Small	High, Very many	High, Very Many	Substantial	Moderate	CM1,2,3,4,5,6 OM1,2,3,4,5,6	Substantial	Moderate	Slight
REC-2	Hikers on Footpath to Trappist Monastery	Small	Small	High, Many	High, Many	Slight	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5	Slight	Insubstantial	Insubstantial
REC-3	Users of Silver Mine Bay Waterfront	Small	Small	High, Very Many	High, Very Many	Moderate	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5	Moderate	Slight	Insubstantial
REC-4	Guests at Silver Mine Beach Resort Hotel (north Block)	Large	Intermediate	Medium, Few	Medium, Few	Substantial	Moderate	CM1,2,3,4,5,6 OM1,2,3,4,5,6	Substantial	Moderate	Moderate
REC-5	Recreational Craft in Silver Mine Bay	Small	Small	High, Few	High, Few	Slight	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5	Slight	Slight	Insubstantial
REC-6	Visitors to Seafood Restaurants along Silver Mine Bay Waterfront	Small	Small	Low, Many	Low, Many	Slight	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5	Slight	Slight	Insubstantial
Travelling VSRs
T-1	Passengers on Inter-Island Ferries	Negligible	Negligible	Low, Very Many	Low, Very Many	Insubstantial	Insubstantial	CM1,2,3,4,5,6 OM1,2,3,4,5	Insubstantial	Insubstantial	Insubstantial
T-2	Drivers/Passengers along Ngan Kwong Wan Road	Small	Small	Medium, Very Many	Medium, Very Many	Slight	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5	Slight	Slight	Insubstantial
T-3	Drivers, Cyclists and Pedestrians along Tung Wan Tau Road	Large	Intermediate	Medium, Very Many	Medium, Very Many	Substantial	Moderate	CM1,2,3,4,5,6 OM1,2,3,4,5	Substantial	Moderate	Moderate
Occupational VSRs
O-1	Workers in Seafood Restaurants along Silver Mine Bay Waterfront	Small	Small	Low, Few	Low, Few	Slight	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5,6	Slight	Slight	Insubstantial
O-2	Fishermen in Silver Mine Bay	Small	Small	Low, Few	Low, Few	Slight	Slight	CM1,2,3,4,5,6 OM1,2,3,4,5	Slight	Slight	Insubstantial
O-3	Workers in Commercial Outlets along Silver Mine Bay Beach	Large	Large	Low, Few	Low, Few	Moderate	Moderate	CM1,2,3,4,5,6 OM1,2,3,4,5	Moderate	Slight	Slight

1.1.1 Silver Mine Bay is a popular bathing beach in Mui Wo, Lantau that attracted 4,550 visitors on a peak day and over 69,000 visitors utilized the beach in 2012.

1.1.3 This Project mainly comprises the following works:

1.1.4 Based on the current design, both New Bridges will be supported by columns outside the river. The preliminary layout of the New Bridges prepared by the Highways Department (HyD) is shown in Figure 1.2.

1.1.5 The Project consists of the following designated projects under Part I, Schedule 2 of the Environmental Impact Assessment Ordinance (EIAO):

1.1.6 A project profile (PP-478/2013) has been submitted to Environmental Protection Department in 28 January 2013 and a study brief (ESB- 256/2013) has been issued to HyD in March 2013.

1.1.7 As an environmental impact assessment (EIA) is required under the Environmental Impact Assessment Ordinance (EIAO), HyD appointed the Joint Venture of Maurice Lee and Associates Ltd. and Cinotech Consultants Ltd. (hereinafter called the JV) to perform the EIA study accordingly.

1.2 Objectives of the EIA Study

1.2.1 The key objectives of the EIA Study are to identify key environmental issues and constraints of the major elements of the Project and to consider possible environmental impact of the schemes and appropriate measures. The detailed objectives are listed as follows:-

1.3.1 The EIA report presents the environmental impact that may arise from the Project and the associated mitigation measures, as follows:-

2.1.4 The purpose, objectives and benefits of project are as follows:

l Demolish the Old Bridge and construct a wider New Bridge (including deck, abutments and retaining walls) with segregation for pedestrians and cyclists to relieve overcrowding problem and road safety concern

l Carry out associated works including drainage works (e.g. u channel & catch pit), traffic aids (e.g. road paint) and street lighting modification (e.g. lighting column & lighting meter cabinet), environmental mitigation measures and landscaping works.

l The ground level of the Old Bridge is about 3.5 mPD. The water level of the Wang Tong River under heavy rain and high tide is about 2.36 mPD. This raises safety concern to the pedestrians of the Old Bridge in case of extreme weather. Therefore, the deck level of New Bridge shall be raised.

Alternative Alignment

2.2.2 In total, three New Bridge options were proposed:

2.2.4 In summary, this design has low structural efficiency with adverse implications on constructability, geotechnical, drainage and environmental impacts and cost. Furthermore, there is room for improvement in the functional and layout arrangement and landscape and visual impacts.

2.2.6 In Option 3, two separated bridges with intermediate support outside the river was proposed to replace the Old Bridge. The advantages of this Option include,

l providing complete separation of cycle track and footpath,

l providing an efficient and safe transition such that building lots abut on the footpath instead of bicycle rack and the cycle track,

l minimizing privacy and security concerns to Silver Mine Bay on the south side by designing the deck level below which bridge user can overlook the interior of hotel,

l providing slimmer New Bridge that reduces the extent of ramp modification and strengthening at both ends and provides adequate freeboard to Wang Tong River,

l avoiding substantial surcharge to existing seawalls and retaining walls,

l minimising construction and demolition works below high water mark (HWM) within Wang Tong River,

l improving drainage performance by eliminating pier of the Old Bridge and raising the soffit of the bridge further above water

l reducing the length of approach ramp which would be received better by the public.

2.2.7 A comparison table on the potential environmental impacts between the three options is shown below:

Table 2.1: Comparison of Bridge Designs

2.3.1 Construction of New Bridge and demolition of Old Bridge involves the following major activities:

Alternative Construction Methods

Consideration of “No-dredge Option”

Demolition of Central Pier of Old Bridge

Piling

Excavation Area of Abutment/Pier of New Bridge

2.3.7 For new cycle bridge, the works area of the southern abutment and central pier of the will be within the HWM by 0.22 m2 and 1.10 m2 respectively.

2.3.8 For new pedestrian bridge, the existing abutments and pile caps will be demolished before construction of the new bridges at the same location. The works area of the southern abutment and central pier of the new cycle bridge will be within the HWM by 3.30 m2 and 3.64 m2 respectively.

2.3.9 While construction at the HWM is required, the water level may not always reach the work site depending on the tidal phase. Therefore, the excavation/dredging at the abutment within HWM during the construction period may be conducted in dry condition.

Bridge Construction

Sequences of Works

2.3.11 To minimize the number of concurrent activities, construction and demolition works will be carried out in sequence:

2.3.12 Although the duration of work will be prolonged, slow work process requires fewer plant equipment and thus produce less noise nuisance.

Preferred Design and Layout

2.4.1 The preferred bridge layout is a twin bridges design having one supporting pier above high water mark (Option 3). This design is beneficial in terms of pedestrian/cyclist safety as well as overall smaller environmental impact:

2.4.2 The deck of the New Bridge is designed at about 5.40mPD highest with 0.3m freeboard, which is capable of passing 1 in 100 year flooding.

Preferred Construction Methods

2.4.3 Minipiling will be adopted for constructing foundation of the New Bridge, which requires smaller space for accommodating the piling machine and this method also generates fewer excavated materials than traditional bored piling.

2.4.5 Existing pile cap at southern abutment of pedestrian bridge is proposed to be demolished.

Detailed Construction Methods

2.4.6 The construction method of the Project can be divided into 3 major parts: 1.) construction of the new cycle bridge, 2.) demolition of old bridge, and 3.) construction of new pedestrian bridge.

Construction of New Bridge (Both cycle and pedestrian bridges)

2.4.7 Procedures for constructing the New Bridge would be as follow:

Demolition of Old Bridge

2.4.8 Procedures for demolishing the Old Bridge would be as follow:

2.5.1 The Project consists of the following designated projects under Part I, Schedule 2 of the Environmental Impact Assessment Ordinance (EIAO):

2.6.1 A project profile (PP-478/2013) has been submitted by Highways Department to Environmental Protection Department on 28 January 2013 and a study brief (ESB- 256/2013) has been issued to HyD in March 2013.

2.7.1 As access across Wang Tong River has to be maintained during construction period, the new cycle bridge will be constructed first before demolition of the Old Bridge and subsequent construction of new pedestrian bridge.

2.7.2 The construction work is expected to last for two years from mid-2017 to mid-2019. The proposed breakdown of programme can be found in Appendix 2A.

2.8.1 Currently, there are one planned and one ongoing projects within the Study Area.

2.8.2 The latest status and activities that are predicted to overlap with the work programme of this Project have been sought from respective project engineers/architects. Details are attached in Appendix 2B.

2.8.3 The scope of HAD project is as follows:

2.8.4 The anticipated construction period is January 2016 – January 2017, which will not overlap with this Project (to be commenced in second half of 2017).

2.8.5 The scope of DSD project is as follows:

2.8.6 Only Scope (c) is located in the vicinity of Wang Tong River Bridge. Sewer laying and manholes construction works were substantially completed and reinstatement works is in progress. The outstanding activities are as follows:

2.8.7 Activity (ii) and (iii) of the DSD project may overlap with this Project in mid-2017. Nevertheless, these are minor works that do not involve use of powered plant equipment or dusty works. No cumulative impact is expected.

3.1.1 This Chapter assesses potential air quality impact arising from both construction and operation of the Project. Where necessary, mitigation measures have been proposed and their effectiveness has been evaluated.

3.5.1 Air Pollutant Control Ordinance (APCO) (Cap 311) and EIAO-TM stipulate statutory Air Quality Objective (AQO) for 7 criteria air pollutants including NO2, SO2, FSP, RSP, CO, O3 and lead.

Construction Phase

3.5.2 This Project involves demolition of an old bridge and construction of two new bridges. Works are planned to commence in July 2017 for completion by June 2019. Major potential air quality impacts during construction phase of the Project would be dust impact arising from:

Operational Phase

3.5.4 Since proposed bridges are designed for pedestrians and cyclists instead of motorized vehicle, no traffic emission is expected during operation. Therefore, no air pollutants listed under the AQO shall be generated during the operational phase of the Project.

3.6.1 This air quality impact assessment has included all proposed works and associated works mentioned in Section 2.1.4.

Construction Phase

3.6.2 Dust generation is the major air quality impact arising from the Project. Nevertheless, with proper implementation of mitigation measures, dust impact arising from the Project is considered insignificant due to the following:

Concurrent Projects

3.6.5 As mentioned in Section 2.8.8, no project that involves heavy construction or dust emitting activity is known to be carried out concurrently with the construction work of this Project. Therefore, no cumulative air quality impact is expected.

Operation Phase

3.6.6 Since proposed bridges are designed for pedestrians and cyclists instead of motorized vehicle, no traffic emission is expected during operation and thus no operational air quality impact is anticipated.

Mitigation of Potential Construction Dust Impact

3.8.2 Dust impact could be effectively mitigated by inclusion of clauses for dust minimisation in the works contract. These dust minimisation clauses should be based on the Air Pollution Control (Construction Dust) Regulation, including but not limited to the followings:

3.8.4 A control programme can be instigated to monitor the construction process in order to enforce dust controls and modify methods of works to reduce the dust emission down to acceptable levels.

3.9.2 Since no air quality impact is expected in operational phase, no air quality monitoring is required in operational phase.

2.3.7 For new cycle bridge, the works area of the southern abutment and central pier of the will be within the HWM by 0.22 m² and 1.10 m² respectively.

2.3.8 For new pedestrian bridge, the existing abutments and pile caps will be demolished before construction of the new bridges at the same location. The works area of the southern abutment and central pier of the new cycle bridge will be within the HWM by 3.30 m² and 3.64 m² respectively.

3.5.1 Air Pollutant Control Ordinance (APCO) (Cap 311) and EIAO-TM stipulate statutory Air Quality Objective (AQO) for 7 criteria air pollutants including NO₂, SO₂, FSP, RSP, CO, O₃ and lead.