8. LANDSCAPE AND VISUAL IMPACT 8.1 Introduction · 2008-04-07 · 8.5.1.12 The assessment of the...

Agreement No. CE 51/2002 (DS)

Upgrading of Pillar Point STW

- Investigation, Design and Construction Final EIA Report

Metcalf & Eddy Ltd. Page 8-1 January 2008

8. LANDSCAPE AND VISUAL IMPACT

8.1 Introduction

8.1.1.1 This section assesses the potential landscape and visual impacts arising from the

proposed upgrading works of the existing Pillar Point STW in accordance with the

criteria and guidelines as stated in Annexes 10 and 18 of the TM and EIAO.

Landscape and visual impacts of any above ground structures and work areas

associated with the project during both construction and operation stages within the

study area will be assessed. Key elements of the proposed works are described

below:-

� Modify and expand the existing aerated grit channel;

� Construct chemically enhanced primary treatment units;

� Construct sludge treatment units which include sludge dewatering facilities and

sludge holding facilities;

� Construct UV irradiation disinfection units;

� Modify and expand the existing septic waste reception facilities;

� Provide odour control facilities; and

� Modify and upgrade the existing ancillary facilities including administration

building, workshop, laboratory and landscaping works.

The dimensions of all the above-ground structures as listed above are:

Approximate dimensions of above-ground structures New structures for

upgraded PPSTW

(Figure 2.3 refers) Width (m) Length (m) Height (m)

New Transformer

Room 6 12 5

Extension of Air

Compressor House 5.5 5.5 4.8

New Aerated Grit

Channel 5.5 13 1.5

New Workshop, New

Admin. Building &

Lab and Control

Room

14 46 9

New Rapid Mixing

Tanks, New

Flocculation Tanks

and New

Sedimentation Tanks

85 95.5 2.5

New Odour Control

Plant I 24 27 7

New Low Lift and

Pumping Station 23.5 25 7

New Chemical

Building 18 45.5 8

Sludge Holding Tank

No. 1, 2, 3 29 38.2 17.5

New Odour Control

Plant II 16.5 27 7





Approximate dimensions of above-ground structures New structures for

upgraded PPSTW

(Figure 2.3 refers) Width (m) Length (m) Height (m)

New Sludge

Dewatering Building 30 31 13.5

New Sludge / Septic Waste Reception Area

15.2 29.7 6

New Return Liquor

Pumping Station 6.2 6.7 0.5

New Sludge Pumping

Station 7 7 0.5

UV Spares Storage

Area 6 16 5

UV Spares Storage

Area 12 13 5

UV Switchgear and

Control Building 6 18 5

Transformer Bay 6 18 5

UV disinfection

Facility 35.3 39.4 0.5

Payment Flowmeter

Chamber 13.4 22.3 2

8.2 Project Overview 8.2.1.1 The scope of the work, construction methodologies and works sites and works areas

for expanding the sewage treatment capacity and upgrading of the existing Pillar

Point STW are described in detail, and illustrated with figures in Section 2. 8.3 Review of Planning and Development Control Framework 8.3.1.1 A review of the existing and planned development framework of the proposed works

and surrounding area are undertaken as input to the Landscape and Visual Impact

Assessment (LVIA). The aim is to identify any issues within the neighbouring

planned land uses, and therefore to identify potential VSRs, and to ensure a high

compatibility between the proposed project and the surroundings.

8.3.1.2 Reference is made to the draft Tuen Mun Outline Zoning Plan No. S/TM/23, and

Site Layout Plan of the Pillar Point Treatment Works from Drainage Services

Department (refer to Section 2). 8.3.1.3 The study area of the Pillar Point STW site falls within an area zoned as “Other

Specified Uses” (OU) annotated “Sewage Treatment Plant” on the draft Tuen Mun

Outline Zoning Plan No. S/TM/23. The upgrading works of the Pillar Point STW

are considered to be highly compatible with the surrounding. 8.4 Environmental Legislation and Standards 8.4.1.1 The methodology for undertaking the LVIA takes reference from Annexes 3, 10 and

18 of EIAO–TM, and in accordance with EIAO Guidance Note No. 8/2002.





8.4.1.2 Other landscape documents relevant for the preparation of the LVIA include:

• Government General Regulation 740 – restrictions on the preservation and

felling of trees in Hong Kong

• The Forests and Countryside Ordinance (Cap96) – prohibits felling, cutting,

burning or destroying of trees and growing plants in forests and plantations on

government land. Its subsidiary regulations prohibit the picking, felling or

possession of listed rare and protected plant species

• The Forestry Regulations – made under Section 3 of the Forests and Countryside

Ordinance (Cap. 96), defined the list of protected species in Hong Kong

• ETWBTC No. 2/2004 – sets out the government departmental responsibilities

for maintenance of vegetation and hard landscape features

• WBTC No. 3/2006 – Tree Preservation, which defines and outlines the

management and maintenance responsibilities for natural vegetation and

landscape works, and the authorities for tree preservation and felling

• WBTC No. 25/93 – Control of Visual Impact of slopes, outlines the design

principles recommended to be used in designing man-made slopes for Public

Works projects in order to reduce their adverse visual impact

• WBTC 17/2000 – Improvement to appearance of slopes, outlines the principles

and procedures recommended for all departments involved in new slope works

and maintenance of existing slopes for improving aesthetic and environmental

impact of slope works

• WBTC No. 7/2002 Tree planting in Public Works, affirms the advocated policy

on tree planting which adopts a flexible and balanced approach in the planning

and design of public works

• WBTC No. 29/2004 Registration of Old and Valuable Trees, and Guidelines for

their Preservation

• GEO publication No. 1/2000 ‘Technical Guidelines on landscape treatment and

Bio-engineering for Man-Made Slopes and Retaining Walls’

• Hong Kong Planning Standards and Guidelines Chapter 4, “Open Space”

• Hong Kong Planning Standards and Guidelines Chapter 10 “Conservation”

• Technical Reports of Landscape Value Mapping in Hong Kong by Planning

Department – establishes the essential landscape baseline information which

provides a systematic reference framework to facilitate landscape assessment.

• Environment Impact Assessment for Development of an EcoPark in Tuen Mun

Area 38 – Final EIA Report.

8.5 Assessment Methodology 8.5.1.1 The Project is a designated project (DP) under the EIAO and the methodology

adopted for the Project conforms to the requirements of the EIAO. The methodology

consists of the following tasks:

• Baseline study of landscape and visual resources

• Landscape impact assessment

• Visual impact assessment

• Recommendation on landscape and visual mitigation measures

• Identification of residual impacts





Baseline Study of Landscape and Visual Resources

8.5.1.2 The study area for the landscape impact assessment shall include all areas within 500

meters from the Project. The study area for the visual impact assessment shall be

defined by the visual envelope of the Project. The defined visual envelope is shown

on Figure 8.4.1.

8.5.1.3 The baseline study identified and examined the existing landscape and visual

resources within the study area. An aerial photograph is used to show the overall

study area and labelled to indicate the Landscape Character Areas (LCAs), while

photographs would be given to demonstrate the Landscape Resources (LRs).

Landscape Resources (LRs) 8.5.1.4 Landscape Resources (LRs) considered the following elements:

• Natural and secondary woodland

• Amenity planting

• Scrubland and grassland

• Natural topography

• Significant planning designation, e.g. Country Park, Green Belt

• Heritage or cultural features

Landscape Character Area (LCA)

8.5.1.5 Field and desk surveys of topographical maps, information databases and

photographs would identify the landscape character (LCA) of the study area. The

character of the landscape is derived from its physical components related to its

visual amenity, cultural association and heritage value. Elements to be considered

include:

• Land use

• Public use of land

• Extent of vegetation

• Age of landscape

• Cultural, heritage and religious elements

• Scale and type of buildings

• Pattern of settlement

• Location and topography

• Extent of natural vs manmade





8.5.1.6 The baseline study describes the LRs by identifying broadly homogenous Landscape

Character Areas (LCAs) of a similar character. The sensitivity of LR / LCAs are

rated low, medium or high. This is influenced by a number of factors including

whether the resources / character is common or rare, whether it is considered to be of

local, regional, national or global importance, whether there are any statutory

limitations / requirements relating to the resource/ character, the quality of the

resource / character, the maturity of the resource, and the ability of the resource /

character to accommodate change.

Visual Resources

Zone of Visual Influence/ Visual Envelope(ZVI)

8.5.1.7 Visual resources are considered as typical viewpoints, with location and direction of

views towards the proposed works. A Zone of Visual Influence/ Visual Envelope is

established which approximately defines the extent of visual influence of the

proposed works, and therefore, of the potential visual impacts. This is achieved by

site visit and desk-top study of topographic maps and photographs, and preparation

of cross-sections to determine visibility of the project from various locations.

Visually Sensitive Receivers (VSRs)

8.5.1.8 Visually Sensitive Receivers (VSRs) who would be present at typical viewpoints and

key views, and likely to be affected by the proposed works, are identified within the

visual envelope. VSRs are defined as individuals or groups of whom are sensitive to

changes in the visual environment. Residents, users of open space/recreational

facilities, road users (private and public transport users), schools, tourists and people

working within the visual envelope shall be considered as VSRs. 8.5.1.9 Each type of VSR is assigned with a number. Description of the view from each

VSR towards the proposed works in terms of location of VSRs, type of VSRs, and

direction of view towards the proposed works, are given and assigned in accordance

with the relative tolerance to change of the VSRs.

8.5.1.10 The sensitivity of VSRs are determined by considering:

• Value and quality of existing views, e.g. urban high-rise, natural hills, sea

view

• Presence and amenity of alternative views

• Type and estimated number of receiver population

Sensitivity Definition

High Important components of landscape of particularly distinctive

character susceptible to relatively small changes

Medium A landscape of moderately valued characteristics reasonably tolerant

of change

Low A relatively unimportant landscape, the nature of which is largely

tolerant to change





• Duration or frequency of view

• Degree of visibility of the proposed project, e.g. no view, glimpse, partial

view, vista, open view, and panorama view)

8.5.1.11 Both present and future VSRs, i.e. from planned developments, would be

considered. The survey information shall be tabulated in a table and summarised in

the text. Drawings to show the location of VSRs and photographs showing typical

views would be included.

Assessment Methodology - Landscape Impacts 8.5.1.12 The assessment of the potential landscape impacts would result from:

• Identification of the source of impact, their magnitude, that would be

generated during construction and operation of the project; and

• Identification of principal impacts, primarily in consideration of the degree of

change to the baseline conditions.

8.5.1.13 The magnitude of change for landscape impact assessment would be determined by

the following factors:

• Compatibility of the project with the surrounding landscape

• Duration of impacts under construction and operation phases

• Scale of the impact

• Reversibility of change

8.5.1.14 The impacts are considered systematically as a product of the sensitivity of the

LCAs and the magnitude of change of the impacts to the landscape. The magnitude

of the change in the landscape is rated large, intermediate, small and negligible as

follows:

Magnitude of Change Definition

Large Notable permanent change in the landscape characteristics over

an extensive area ranging to very intensive changes over a more

limited area

Intermediate Moderate changes in a localised area

Small Virtually imperceptible change or temporary change

Negligible Virtually no changes in the area

8.5.1.15 The following factors are considered to the judgement of the overall landscape

impacts:

• The landscape character and its quality

• The sensitivity of the landscape in accommodating change

• Source, nature and magnitude of potential impacts

• Construction and operation phases impacts

• Degree of change caused by each of the impacts to the existing LCAs

• Significance of this change in the local and regional context and in relation to

other developments





• Cumulative effects on the landscape of this and neighbouring projects

8.5.1.16 The overall impact likely to occur to LCAs, is derived from the magnitude of change

which the project would cause to the existing landscape and ability to tolerate the

change. A matrix shall be used to demonstrate the overall impact:

Sensitivity / Quality of the landscape

Low Medium High

Large Slight /

moderate

Moderate /

Substantial Substantial

Intermediate Slight /

Moderate Moderate

Moderate /

Substantial

Small Insubstantial /

Slight Slight / Moderate

Moderate /

slight Mag

nit

ude

of

Chan

ge

Negligible Insubstantial Insubstantial Insubstantial

8.5.1.17 Furthermore the impacts need to be identified as Adverse, Beneficial or Neutral,

which indicate the impact on the existing landscape context as follows:

8.5.1.18 The product of the LIA is termed the Significance Threshold, and shall be

considered as follows:

Identification of

the Landscape

Impact

Definition

Adverse An impact which will be detrimental to the existing landscape

context

Beneficial An impact which will improve the existing landscape context

Neutral An impact which will alter the existing landscape context but not to

improve or destroy it

Impacts

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 the existing landscape quality

Insubstantial No discernible change in the existing landscape quality




Metcalf & Eddy Ltd. -8 January 2008

Assessment Methodology - Visual Impacts

8.5.1.19 The baseline survey forms the basis of the visual impact assessment, and shall result

from:

• Identification of the source of visual impacts, their magnitude of change and

sensitivity of the receivers, that would be generated during construction and

operation of the project, and;

• Identification of principal visual impacts, primarily in consideration of the

degree of change to the baseline conditions

8.5.1.20 The magnitude of change for visual impact assessment would be determined by the

following factors:

• Compatibility of the proposed project with the surrounding landscape

• Duration of impacts during construction and operation stages

• Scale of impact and distance of the source of impact from the viewer

• Reversibility of impact

• Potential blockage of the view

8.5.1.21 The overall impact likely to occur to VSRs, is derived from the magnitude of change

which the project would cause to the existing visual context and its ability to tolerate

the change. A matrix shall be used to demonstrate the overall impact:

Sensitivity / Quality of the Visual Receivers

Low Medium High

Large Moderate Moderate /

Substantial

Substantial

Intermediate Slight / moderate Moderate Moderate /

Substantial

Small Slight Slight / Moderate Moderate

Mag

nit

ude

of

Chan

ge

Negligible Insubstantial Insubstantial Insubstantial

8.5.1.22 Furthermore the impacts need to be identified as Adverse, Benefit or Neutral, which

indicate the impact on the existing visual context as follows:

Identification of

the Visual Impact

Definition

Adverse An impact which will be detrimental to the existing views

Beneficial An impact which will improve the existing views

Neutral An impact which will alter the existing views but not to improve

or destroy it





8.5.1.23 The product of the VIA is termed the Significance Threshold, and shall be

considered as follows:

Identification of Potential Landscape and Visual Impact Mitigation Measures

8.5.1.24 After assessing and identifying the landscape and visual impacts of the proposed

works which likely to occur and how significant these impacts would be,

recommendations would then be formulated to reduce or alleviate these impacts both

during the construction and operation stages. The agencies responsible for the

funding, implementation, management and maintenance of the mitigation measures

have been identified and their approval-in-principle will be sought.

Identification of Residual Impacts

8.5.1.25 This is a further assessment to establish residual impacts that persist after the

implementation of mitigation measures.

8.5.1.26 The principles for undertaking the residual impact assessment are similar to the

landscape and visual impact assessments. Significance threshold for the residual

impacts would be established to consider the impacts against the successfulness of

the recommended mitigation measures to alleviate such impacts.

Impacts

Substantial Adverse/beneficial impact where the proposal would cause significant

deterioration or improvement in existing views

Moderate Adverse/beneficial impact where the proposal would cause a noticeable deterioration or improvement in existing views

Slight Adverse/beneficial impact where the proposal would cause a barely

perceptible deterioration or improvement in the existing views

insubstantial No discernible change in the existing views





8.6 Baseline Study

Landscape Resources (LR)

8.6.1.1 Several landscape resources have been identified within the study area. These are

described below and mapped in Figure 8.2.1 and with photographic record in

Figure 8.2.2 & 8.2.3. The approximate locations of the tree groups within the study

boundary are indicated in Figure 8.9.2. Name of the LRs is listed and a description

of each LR is summarized as follows:

LR1 - Water Body LR2 - Stream Course

LR3 - Disturbed Hillside Plantation

LR4 - Scrubland/ Woodland Natural Terrain

LR5 - Roadside Planting

LR6 - Vegetation within existing DSD Sewage Treatment Works

LR7 - Vegetation within Industrial Area

LR8 - Golf Course

8.6.1.2 LRs findings from the baseline study are summarized in Table 8.1:

Table 8.1 Illustration of the Sensitivity of LRs in Study area

Id. No. Vegetation Feature Dominant Tree Species Function Sensitivity

LR 1 Water Body N.A. As habitat

purpose Low

LR 2

Stream course

(natural / artificial

channel)

N.A. As habitat

purpose Medium

LR 3 Disturbed hillside

plantation area Casuarina equisetifolia

As habitat

purpose Medium

LR 4 Scrubland/ Woodland

natural terrain

- Acacia confusa, Ficus microcarpa,

Sapium discolor, Sapium sebiferum,

Mallotus paniculatus, Litsea

glutinosa, Celtis sinensis, Sterculia

lanceolata, Casuarina equisetifolia,

Musa paradisiaca, Macaranga

tanarius, and other native tree

species, etc.

Public usage High

LR 5 Roadside planting Delonix regia, Cassia siamea Public usage medium

LR 6

Vegetation within

existing DSD sewage

treatment Works

343 no of exsting trees are recorded

in general height from 4m to 13m,

trunk diameter from 95mm to 300mm

and a spread from 2 to 13; they are

mainly Casuarina equisetifolia,

Hibiscus trifolia, Ficus elastica,

Leucaena leucocephala

Public usage medium

LR 7 Vegetation within

industrial area

Casuarina equisetifolia, Hibiscus

trifolia, Cassia siamea Public usage Medium

LR 8 Golf course N.A. Recreational

purpose Low

8.6.1.3 Apart from LR6, most the trees at other LRs are common species found with

approximately height from 4m to 13m, trunk diameter from 95 mm to 250 mm and

spread from 3 to 10. Amenity value of most of the existing trees is fair in average.





Landscape Character Area (LCA)

8.6.1.4 A baseline review has been undertaken of the landscape resources, landscape

character areas (LCA), zone of visual influence, and visual sensitive receivers. The

study area consists of five distinct LCA. The LCA are mapped in Figure 8.3.1 and

photographic record are illustrated in Figure 8.3.2. A description of each LCA is

provided as follows:

• LCA 1 – Transport Corridor Landscape Character Area, which represents

vehicular roads such as Lung Mun Road Highway.

• LCA 2 – Upland & Hillside Landscape Character Area, which represents all

hillside plantation area, including roadside amenity areas along Lung Mun

Road Highway. It also contains woodlands, scrubland and fresh water body,

which represent the major character of the area.

• LCA 3 – Inshore Water Landscape Character Area, which represents seawater

body and waterfront character such as breakwaters and seashore at the south of

the River Trade Terminal.

• LCA 4 – Institutional Landscape Character Area, which represents all

government institutions and public utilities such as existing Pillar Point STW,

EMSD Tuen Mun Vehicular Servicing Station, Harbor Hydraulics Laboratory,

Physical Model Lab Sub-station, Pillar Point Fire Station and WSD Tuen Mun

West Fresh Water Service Reservoir.

• LCA 5 – Industrial Urban Landscape Character Area, which represents all

industrial zone in the reclaimed area of Ho Fuk Street and Ho Yeung Street

such as River Trade Terminal & cargo handling area.





Visual Sensitive Receivers (VSRs)

8.6.1.5 Table 8.2 and Table 8.3 indicate the Sensitivity to Change and Magnitude of the Impacts in VSRs accordingly found within the ZVI’s

for the construction phase and operational phase. For ease of reference, each VSR is given an identity number, and mapped in Figure

8.4.1 and with photographic record in Figures 8.4.2 & 8.4.3. Table 8.2 summarises the characteristics of key views as seen in the

photomontages. All impacts are adverse unless otherwise stated.

Table 8.2 Identity of key Visual Sensitive Receivers (VSRs) and Their Sensitivity to Change

Id. No. Key Visual Sensitive

Receivers (VSRs) Type of VSRs

Number of

Individuals

(Many/ Medium/

Few/ Very Few)

Quality

of

Existing

View (Good/

Fair/

Poor)

Availability

of

Alternative

Views (Yes/ No)

Amenity of

Alternative

Views

(Good/Fair/

Poor)

Degree of

Visibility

(Full/

Partial/

Glimpse)

Frequency of View (Very

Frequent/

Frequent/

Occasional/

Rare)

Sensitivity to

Change

(Low,

Medium,

High)

OU1 River Trade Terminal &

Cargo Handling Area Occupational Many Fair Yes Fair

Full Occasional Low

OU2 River Trade Golf Course Recreational Many Fair Yes Fair Glimpse Rare Medium

OU3

Planned Development in

Tuen Mun Area 38 – Eco

Park and Waste Sorting

Facilities

Occupational Medium Fair Yes

Fair

Glimpse Rare Low

GIC1

EMSD Tuen Mun Vehicle

Servicing Station, Harbour

Hydraulics Laboratory and

Physical Model Lab Sub-

station

Occupational Medium Fair Yes

Fair

Partial Rare Low

GB1 Castle Peak Recreational Few Good Yes Fair Partial Rare Low

T1 Lung Mun Road Transportation Medium Fair Yes Fair partial Frequent Low

R = Residential; C = Commercial, GIC = Government/Institution/Community, O = Open space, OU = Others use; T = Transport related





Table 8.3 Visual Sensitive Receivers (VSRs) and Their Magnitude of Impacts

Magnitude of Impacts

(Large/ Intermediate/ Small/

Negligible Id No. Key Visual Sensitive Receiver (VSR)

Blockage

of View

(Full/

Partial/

Glimpse

Viewing

Distance

(M)

Scale of

Development

(Large/

Medium/

Small)

Compatibility

(Good/ Fair/

Poor)

Reversibility

of Change

(Yes/ No) Construction Operation

OU1 River Trade Terminal & Cargo Handling

Area Partial 10 Large Good No Intermediate Intermediate

OU2 River Trade Golf Course Glimpse 150 Medium Good No Small Small

OU3

Planned Development in Tuen Mun Area

38 – Eco Park and Waste Sorting

Facilities

Glimpse 650 Small Good No

Negligible Negligible

GIC1

EMSD Tuen Mun Vehicle Servicing

Station, Harbour Hydraulics Laboratory

and Physical Model Lab Sub-station

Glimpse 25 Large Good No

Intermediate Intermediate

GB1 Castle Peak Glimpse 25 Large Good No Intermediate Intermediate

T1 Lung Mun Road Glimpse 10 Large Good No Small Small

R = Residential; C = Commercial, GIC = Government/Institution/Community, O = Open space, OU = Others use; T = Transport related





8.7 Landscape Impact Assessment (LIA)

Sources of Landscape and Visual Impacts 8.7.1.1 The nature and extent of the sewage plant upgrading works, works areas and the

construction methodologies are described in detail in Section 2. For easy of

reference, the extent of works at ground level, including all contractors’ temporary

works area, are shown on all the plans illustrating landscape and visual impacts in

this section.

8.7.1.2 The sources of landscape and visual impacts in the construction phase will include:-

� construction works involving the removal of existing vegetation;

� construction of site access;

� excavation works for the sedimentation tank and sludge holding tank;

� stockpiling of excavated materials;

� haulage off-site of excavated materials

� stockpiling of construction materials;

� importation and storage of construction equipment and plant;

� contractor’s temporary works areas, including site accommodation and

parking area;

� construction of above ground features such as new administration building,

laboratory, and control room; and

� night lighting;

8.7.1.3 During the operation stage, potential landscape and visual impacts would be related

to the following visible above ground structures:

� new administration building, laboratory and control room (approximately 8m

height);

� chemical storage building and chemical dosing area (approximately 8m

height);

� low lift and returns pumping station / odour control units (approximately 7m

height);

� rapid mixing tanks, flocculation tanks and sedimentation tanks (approximately

2.5m height);

� UV disinfection facilities (approximately 0.5-5m height);

� sludge holding tanks (approximately 17.5m height);

� sludge dewatering building (approximately 13.5m height);

� septic waste reception area (approximately 6m height)





Landscape Impact Assessment

Nature and Magnitude of Landscape Change Before Mitigation in Construction

Phase

8.7.1.4 The magnitude of the impacts, before implementation of mitigation measures, on the

landscape resources and LCA that would occur in the construction phase are

described below and tabulated in Table 8.4. Only those resources and character

areas that would be impacted are listed. All impacts are adverse unless otherwise

stated.

LR6-Vegetation within existing sewage treatment plant There would be a large change to the existing Pillar Point STW due to the excavation

works of the sedimentation tanks and associated structures, and site access. There are

a total approx. 343 trees within the Pillar Point STW. The approximate location of

the existing trees and the broadbrush tree survey results (including the general

species name) are shown in Figure 8.9.2. There would be impacts on approximately

90 numbers of trees, of which all have a high to low amenity value. The locations as

well as the assessment schedule for the 90 numbers of the affected trees are shown in

Figure 8.9.3. Those affected trees have a height from 4m to 13m, trunk diameter

from 95mm to 300mm and a spread from 2 to 13. Apart from the 18 numbers of

“Leucaena leucocephala”, which are proposed to be felled in accordance with

ETWB TCW No. 3/2006, all the affected trees are capable of transplanting, although

the largest trees would suffer some loss of form and amenity value during

transplanting process.

8.7.1.5 In addition to the above impacts on landscape resources, there would be moderate

magnitude of change on LCA4 due to excavation works within the existing STW,

temporary works areas, stockpiling of excavated materials, and associated impacts

on trees as described above.

8.7.1.6 There would be negligible magnitude of impact on all the remaining landscape

character areas.

Predication of Significance of Landscape Impacts

8.7.1.7 The potential significance of the landscape impacts during the construction and

operational phases, before and after mitigation, are provided in Table 8.4. The

landscape impacts for the construction and operational phases after mitigation are

mapped in Figures 8.5.1 to 8.5.4. This assessment follows the stated methodology

and assumes that the appropriate mitigation measures identified in previous section

would be implemented, and that the full effect of the soft landscape mitigation

measures would be realised after ten years. Photomontages of the proposed

development are illustrated in Figure 8.7.1 and Figure 8.7.2.

Operational Phase Landscape Impacts





8.7.1.8 Residual landscape impacts on landscape resources in the operation phase are

mapped in Figure 8.5.2. Residual landscape impacts on LCA in the operational

phase are mapped in Figure 8.5.4.

8.7.1.9 All residual adverse landscape impacts in the operational phase of Day 1 will be of

insubstantial significance, with the exception of the impacts on existing vegetation

within the existing Pillar Point STW (LR7), where an adverse impact of slight

significance is anticipated due to the permanent alienation of existing planting area

and approx. 90 no. trees due to the upgrading of Pillar Point STW. After all

landscape mitigation measures are implemented and have matured over 10 years,

there would be no residual adverse landscape impacts of any significance in Year 10.

8.8 Visual Impact Assessment (VIA)

8.8.1.1 The potential sources of landscape and visual impacts are described above in

Sections 8.7.1.1-8.7.1.3.

Visual Impacts at Construction Stage before Mitigation

8.8.1.2 Workers on River Trade Terminal & Cargo Handling Area (OU1), EMSD lab sub-

station (GIC1) and leisure walkers (GB1) will receive moderate impact towards to

the proposed upgrading works as they are both really closed to Project.

8.8.1.3 Golf player (OU2) and Lung Mun Road (T1) will have intermittent views to the

construction works. As roadside vegetation screening off most of the Project

boundary; therefore visual impact is slight.

8.8.1.4 Workers and visitors in Eco Park (OU3) will have fairly distant views to the

proposed works which will be frequently screened by the containers from the River

Trade Terminal and topographic changes in vary locations. Therefore visual impact

is insubstantial before mitigation.

Residual Visual Impacts at Construction Stage after Mitigation

8.8.1.5 Residual visual impacts in the construction phase are mapped in Figures 8.5.1 &

8.5.3. Adverse impacts of significance during the construction phase which would be

experienced by the VSRs are listed below. This would be primarily because of the

cut & cover excavation, stockpiling of excavated materials; temporary works sites

and works area, temporary traffic diversions, the associated removal of trees, either

by felling or transplanting, and the obstruction of views arising from boarding.

8.8.1.6 Workers on River Trade Terminal & Cargo Handling Area (OU1) will still have

moderate residual impact as most of mitigation measures implementation can not all

comprehensively instated of disturbance of views towards to the proposed upgrading

works as they are both are directly or relatively close to Project.





8.8.1.7 The residual adverse visual impacts in construction stage on OU2, GIC1, GB1 and

T1 are slight after the implementation of visual mitigation measure. As most VSRs

will have intermittent views to the Project.

8.8.1.8 OU3 will have insubstantial adverse visual impact.

Visual Impacts at Operation Stage before Mitigation

8.8.1.9 The potential significance of the visual impacts during the operate phase, before and

after mitigation, are briefly described below, provided in detail in Table 8.5, and

illustrated in Figure 8.5.6. This assessment follows the methodology outlined in

Section 8.5 and assumes that the appropriate mitigation measures identified in Table

8.7 below would be implemented.

8.8.1.10 Workers on River Trade Terminal & Cargo Handling Area (OU1), EMSD lab sub-

station (GIC1) and leisure walkers (GB1) will receive moderate impact towards to

the proposed upgrading works as they are both really closed to Project.

8.8.1.11 Golf player (OU2) and Lung Mun Road (T1) will have intermittent views to the

construction works. As roadside vegetation screening off most of the Project

boundary; therefore visual impact is slight.

8.8.1.12 Workers and visitors in Eco Park (OU3) will have fairly distant views to the

proposed works which will be frequently screened by the containers from the River

Trade Terminal and topographic changes in vary locations. Therefore visual impact

is insubstantial before mitigation.

8.8.1.13 The adverse impacts on OU3 is insubstantial.

Residual Visual Impacts at Operation Stage after Mitigation

8.8.1.14 A residual visual impact in the operational phase is mapped in Figure 8.5.6 and was

demonstrated in photomontage view Figures 8.7.1 and 8.7.2.

8.8.1.15 Day 1 after the implementation of mitigation measures during operation there would

still be some slight negative visual impact on the VSRs on OU1 which are close to

the Project. 10 years after the implementation of mitigation measures during

operation, the residual impacts on all VSRs are insubstantial. Overall, it is

considered that the residual landscape and visual impacts of the proposed

development are considered as acceptable with mitigation measures during

construction and operation phase.





Table 8.4 Significance of landscape impacts in the construction and operation phases (Note: All impacts adverse unless otherwise

noted. Only those resources or character areas that are impacted are listed in the table – resources not impacted are not

listed. )

Part 1 – Physical Landscape Resources (Topography, Vegetation, Soil, Open Space, Special Features, etc) Magnitude of Change before

Mitigation

(Negligible, Small,

Intermediate, Large)

Impact significance

Threshold Before Mitigation

(Insubstantial, Slight,

Moderate, Substantial)

Residual Impact Significance Threshold

After Mitigation

(Insubstantial, Slight, Moderate,

Substantial)

Operation

Id. No. Landscape Resources (LR)

Sensitivity

to Change

(Low,

Medium,

High) Construction Operation Construction Operation

Recommended Mitigation

Measures*

Construction DAY 1 YEAR 10

LR1 Water Body High Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LR2 Stream Course (natural artificial

channel) Medium Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LR3 Disturbed Hillside Plantation Medium Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LR4 Scrubland / Woodland Natural

Terrain High Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LR5 Roadside Planting Medium Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LR6 Vegetation within Existing DSD

Sewage Treatment Works Medium Intermediate Intermediate Moderate Moderate

CM1, CM2, CM5, CM6

OM1, OM2, OM3 Moderate Slight Insubstantial

LR7 Vegetation within Industrial Area Medium Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LR8 Golf Course Low Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

* Recommendation on landscape and visual mitigation measures are described in Section 8.9.





Part 2 – Landscape Character Areas Magnitude of Change

before Mitigation

(Negligible, Small,

Intermediate, Large)

Impact significance Threshold

Before Mitigation

(Insubstantial, Slight,

Moderate, Substantial)

Residual Impact Significance Threshold

After Mitigation

(Insubstantial, Slight, Moderate,

Substantial)

Operation

Id. No. Landscape Character Area (LCA)

Sensitivity to

Change

(Low,

Medium,

High) Construction Operation Construction Operation

Recommended

Mitigation

Measures*


LCA1 Transport Corridor Landscape Character Area Medium Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LCA2 Upland & Hillside Landscape Character Area High Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LCA3 Inshore Water Landscape Character Area Low Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

LCA4 Institutional Landscape Character Area Medium Negligible Negligible Insubstantial Insubstantial

CM1, CM2,

CM5, CM6

OM1, OM2,

OM3

Moderate Slight Insubstantial

LCA5 Industrial Urban Landscape Character Area Low Negligible Negligible Insubstantial Insubstantial N/A Insubstantial Insubstantial Insubstantial

* Recommendation on landscape and visual mitigation measures are described in Section 8.9.





Table 8.5 Significance of visual impacts in the construction and operational phases (Note: All impacts adverse unless otherwise

noted. Only those VSRs that are impacted are listed in the table – VSRs not impacted are not listed.)

Magnitude of Change in

View before Mitigation

(negligible, small,

intermediate, large)

Receptor Sensitivity

(Low, medium, High)

Impact significance

threshold before

mitigation

(insubstantial, slight,

moderate, substantial)

Residual Impact Significance

Threshold after Mitigation

(insubstantial, slight, moderate,

substantial)

Operation

VSR

Type

& ID

Key Visually Sensitive Receiver

(VSR)

Construction Operation Construction Operation Construction Operation

Recommended

Mitigation

Measures*


OU1 River Trade Terminal & Cargo Handling

Area Intermediate Intermediate Low Low Moderate Moderate

CM1, CM3, CM5, CM7, OM2, OM3

Moderate Slight Insubstantial

OU2 River Trade Golf Course Small Small Medium Medium Slight Slight CM1, CM3, CM5,

CM7, OM2, OM3 Slight Insubstantial Insubstantial

OU3 Planned Development in Tuen Mun Area

38 – Eco Park and Waste Sorting Facilities Negligible Negligible Low Low Insubstantial Insubstantial

CM1, CM3, CM5,

CM7, OM2, OM3 Insubstantial Insubstantial Insubstantial

GIC1

EMSD Tuen Mun Vehicle Servicing

Station, Harbour Hydraulics Laboratory

and Physical Model Lab Sub-station

Intermediate Intermediate Low Low Moderate Moderate CM1, CM3, CM5,


GB1 Castle Peak Intermediate Intermediate Low Low Moderate Moderate CM1, CM3, CM5,


T1 Lung Mun Road Small Small Low Low Slight Slight CM1, CM3, CM5,


R = Residential; C = Commerciall, GIC = Government/Institution/Community, O = Open space, OU = Others use; T = Transport related * Recommendation on landscape and visual mitigation measures are described in Section 8.9.





8.9 Recommendation on Landscape and Visual Mitigation Measures

8.9.1.1 The proposed landscape and Visual mitigation measures in the construction and

operational phases are listed in Table 8.6 and Table 8.7 below, together with an

indication of Funding, Implementation, and Management and Maintenance agencies.

Table 8.6 Proposed Landscape and Visual Mitigation Measures in Construction

Phase

ID No. Nature / Type Landscape and Visual Mitigation Measure Implementation

Agent

Management

/

Maintenance

CM1 Design /

construction

Planning

Temporary Tree Nurseries

Temporary tree nurseries may be set up for the transplanted tree

and proposed trees at an early stage to allow small trees to grow

during the construction periods. By the time when planting area

becomes available, trees mature and increase in trunk & spread

size. They will require minimal pruning and suffer much less

damage during transplanting when comparing the travel distance

from an on-site nursery to an off-site nursery.

Besides, these trees may also be positioned as visual mitigation

during the construction period.

Potential site and locations should sought agreement with

relevant department in advance and avoid doubling

transplantation procedure.

Contractor Contractor

CM2 Design /

construction

Planning

No-intrusion Zone

To maximize protection to existing trees and ground vegetation,

construction contracts may designate “No-intrusion Zone” to

various areas within the site boundary with rigid and durable

fencing for each individual no-intrusion zone. The contractor

should close monitor and restrict the site working staff not to

enter the “no-intrusion zone”, even for non-direct construction

activities and storage of equipment.


CM3 Design /

construction

Planning

Hoarding

Hoarding or boundary fencing for construction shall be

considered. It should be sensitively designed, subtle,

camouflaged and more ‘permeable’ so that they fit into the

existing environment when looking from outside.


CM5 Site Practice Dust and Erosion Control for Exposed Soil

Excavation works and demolition of existing building blocks and

which will be highly visible form surrounding areas should be

well planned and with precautions to suppress dust. Exposed soil

shall be covered or ‘camouflaged’ and watered often. Areas that

are expected to be left with bare soil for a long period of time

after excavation shall be properly covered with suitable

protective fabric. Silt and erosion shall be controlled by ground

barriers around the slope cutting area.


CM6 Site

Supervision

Existing Tree Record Inventory

All retained trees should be record photographically at the

commencement of the Contract, and carefully protected during

the construction period. Detailed tree protection specification

shall be allowed and included in the Contract Specification,

which specifying the tree protection requirement, submission

and approval system, and the tree monitoring system.


CM7 Site Practice Construction Light

All security floodlights for construction sites shall be equipped

with adjustable shield, frosted diffusers and reflective covers,

and be carefully controlled to minimize light pollution and night-

time glare to nearby residences and GIC users. The Contractor

shall consider other security measures which shall minimize the

visual impacts.


CM8 Design / Tree Transplanting Contractor Contractor





ID No. Nature / Type Landscape and Visual Mitigation Measure Implementation

Agent

Management

/

Maintenance

construction

Planning

Apart from the 18 numbers of “Leucaena leucocephala”, which

are proposed to be felled in accordance with ETWB TCW No.

3/2006, all the affected trees shall be transplanted. Where

practicable, trees shall be directly transplanted to permanent on-

site locations. The location of the transplanted tree is shown in

Figure 8.9.1.

CM9 Design /

construction

Planning

Tree Compensation Ratio

The total number of compensatory trees planted in the project

area shall not be less than 1:1 ratios by new trees. Required

numbers and locations of compensatory trees shall be

determined and agreed with Government during the tree felling

application process under ETWCTC 3/2006.

Compensatory trees shall be at least heavy standard size to create

“immediate” greening effect.

81 numbers of “Cassia surattensis” will be provided as the

additional compensatory planting for loss of greenery in the area

due to removal of the affected trees. The location of the

additional compensatory planting is shown in Figure 8.9.1.


CM10 Design /

construction

Planning

Re-use of Existing Soil and Advance formation of Planting Area

Existing topsoil shall be re-used where possible for new planting

areas within the project. Advance formation of planting area and

early implementation of the plating works can minimize adverse

impact on trees. The construction program shall consider using

the soil removed from one phase for backfilling another. Suitable

storage ground, gathering ground and mixing ground may be set

up on-site as necessary.


Table 8.7 Proposed Landscape and Visual Mitigation Measures in Operation Phase ID No. Nature / Type Landscape and Visual Mitigation Measure Implementation

Agent

Management

/

Maintenance

OM1 Site

Supervisions

Establishment Period

12 month establishment period for the soft landscape works

will be allowed in the main contract. Most construction

contracts in Hong Kong require the Contractor to carry out

routine horticultural operations, including watering, pruning,

weeding, pest control, replacement of dead plants etc. to

ensure healthy establishment of new planting during a 12

month establishment period. This period also serves as a kind

of warranty / guarantee on the quality of the plants supplied

and installed by the Contractor. Monthly monitoring during

the first year of establishment period is recommended.

PPSTW

Operator

PPSTW

Operator

OM2 Design /

construction

Planning

Re-instatement of excavated Area

All excavated area and disturbed area for utilities diversion,

temporary road diversion, and pipeline woks will be

reinstated to former conditions, subject to applicable

Government Standards.

PPSTW

Operator

PPSTW

Operator

OM3 Design /

construction

Planning

Appearance and Greening for the proposed structures

Compatible design, construction materials and surface

finishes of the proposed structure should match with the

nearby existing external appearance of PPSTW buildings for

achieving visual uniformity. Finishing materials shall have

due consideration to form, basic color, color/tone variation,

micro- and macro-texture, and reflectivity/light absorbance to

avoid glare. Planting, such as turf, low groundcovers and

climbers, may also be planted on top of these elements to

provide greening and aesthetic effect.

PPSTW

Operator

PPSTW

Operator





8.10 Conclusions

Summary of Predicated Residual Landscape and Visual Impacts in the

Construction Phase

8.10.1.1 Residual landscape impacts in the construction phase are listed in Table 8.4 and

mapped in Figures 8.5.1 and 8.5.3. Residual visual impacts in construction phase are

listed in Table 8.5 and mapped in Figure 8.5.5.

8.10.1.2 There are a total approx. 343 trees within the Pillar Point STW, the approximate

location of the existing trees and the broadbrush tree survey results (including the

general species name) are shown in Figure 8.9.2. Of these, 253 trees are proposed to

be retained, 90 trees will be affected. The species of all the affected trees are listed

in Figure 8.9.3 and none of them are classified as the Old and Valuable (OVT) trees.

Apart from the 18 numbers of “Leucaena leucocephala”, all the affected trees are

proposed to be transplanted. The 18 numbers of “Leucaena leucocephala” are

proposed to be felled in accordance with ETWB TCW No. 3/2006. There will be

mitigation through the transplanting of some existing trees and the planting of new

stock. Moreover, 81 numbers of “Cassia surattensis” will be provided as the

additional compensatory planting for loss of greenery in the area due to removal of

the affected trees. Locations of the transplanted trees (total 72 numbers) and

additional compensatory planting (total 81 numbers) are shown in Figure 8.9.1.

8.10.1.3 There is expected to be moderate impacts on the existing institutional areas (LCA4)

during construction to the landscape character of the Government utilities area.

8.10.1.4 Workers on River Trade Terminal & Cargo Handling Area (OU1) would have

moderate adverse visual impact during construction phase. Impact would be lessen

as slight in operational stage when landscape and visual mitigation measures are

fully implemented. The visual impact would be insubstantial significance as most of

the tree planting would provide proper screening effect in maturity of 10 years.

Summary of Predicated Residual Landscape and Visual Impacts in the

Operational Phase

8.10.1.5 Day 1 after the implementation of mitigation measures during operation there would

still be some slight negative visual impact on the VSRs close to the Project on OU1.

10 years after the implementation of mitigation measures during operation, the

residual impacts on all VSRs are insubstantial.

8.10.1.6 After the proposed mitigation measures have been implemented and the proposed

tree planting has matured over 10 years, all residual adverse landscape and visual

impacts in operational phase will be of insubstantial significance.

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