9                                            Ecology

9.1                                      Introduction

This Section presents the baseline condition of ecological resources within the Study Area ([1]), and the results of an assessment of the potential ecological impacts due to the construction, operation, restoration and aftercare of the Extension. 

Baseline conditions for ecological components of the terrestrial and associated aquatic environment were evaluated based on information from available literature sources and focussed field surveys conducted for the purposes of this EIA.  Measures required to mitigate any identified adverse impacts are recommended, where appropriate.

9.2                                      Relevant Legislation and Guidelines

A number of international conventions and local legislation and guidelines provide the framework for the protection of species and habitats of ecological importance.  Those related to the Extension are as follows:

·           Forests and Countryside Ordinance (Cap 96);

·           Town Planning Ordinance (Cap 131);

·           Wild Animals Protection Ordinance (Cap 170);

·           Protection of Endangered Species of Animals and Plants Ordinance (Cap 586);

·           Hong Kong Planning Standards and Guidelines Chapter 10 (HKPSG);

·           The Technical Memorandum on Environmental Impact Assessment Process under the Environmental Impact Assessment Ordinance (EIAO-TM);

·           United Nations Convention on Biodiversity (1992); and

·           PRC Regulations and Guidelines.

The Forests and Countryside Ordinance prohibits felling, cutting, burning or destroying of trees and growing plants in forests and plantations on Government land.  The subsidiary Forestry Regulations prohibit the picking, felling or possession of listed rare and protected plant species.  The list of protected species in Hong Kong which comes under the Forestry Regulations was last amended on 11 June 1993 under the Forestry (Amendment) Regulation 1993 made under Section 3 of the Forests and Countryside Ordinance.

Under the Wild Animals Protection Ordinance, designated wild animals are protected from being hunted, whilst their nests and eggs are protected from destruction and removal.  All birds and most mammals including all cetaceans are protected under this Ordinance, as well as certain reptiles, amphibians and invertebrates.  The Second Schedule of the Ordinance that lists all the animals protected was last revised in June 1997.

The Protection of Endangered Species of Animals and Plants Ordinance (Cap 586) was enacted to align Hong Kong to control regime with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). With effect from 1 July 2006, it replaces the Animals and Plants (Protection of Endangered Species) Ordinance (Cap 187).  The purpose of the Protection of Endangered Species of Animals and Plants Ordinance is to restrict the import and export of species listed in CITES Appendices so as to protect wildlife from overexploitation or extinction.  The Ordinance is primarily related to controlling trade in threatened and endangered species and restricting the local possession of them.

The recently amended Town Planning Ordinance provides for the designation of areas such as “Coastal Protection Areas”, “Sites of Special Scientific Interest (SSSIs)”, “Green Belt” and "Conservation Area” to promote conservation or protection or protect significant habitat.  Chapter 10 of the HKPSG covers planning considerations relevant to conservation.  This chapter details the principles of conservation, the conservation of natural landscape and habitats, historic buildings, archaeological sites and other antiquities.  It also addresses the issue of enforcement.  The appendices list the legislation and administrative controls for conservation, other conservation related measures in Hong Kong, and Government departments involved in conservation.

Annex 16 of the EIAO-TM sets out the general approach and methodology for assessment of ecological impacts arising from a project or proposal, to allow a complete and objective identification, prediction and evaluation of the potential ecological impacts.  Annex 8 recommends the criteria that can be used for evaluating ecological impacts.

The Peoples’ Republic of China (PRC) is a Contracting Party to the United Nations Convention on Biological Diversity of 1992.  The Convention requires signatories to make active efforts to protect and manage their biodiversity resources.  The Government of the Hong Kong SAR has stated that it will be “committed to meeting the environmental objectives” of the Convention (PELB 1996).

In 1988 the PRC ratified the Wild Animal Protection Law, which lays down basic principles for protecting wild animals.  The Law prohibits killing of protected animals, controls hunting, and protects the habitats of wild animals, both protected and non-protected.  The Law also provides for the creation of lists of animals protected at the state level, under Class I and Class II.  There are 96 animal species in Class I and 156 in Class II.  Class I provides a higher level of protection for animals considered to be more threatened.

9.3                                      Study Area for the Ecological Impact Assessment

The Study Area for the purpose of the terrestrial ecological assessment included all areas within 500m of the boundary of the Extension Site, including part of the existing SENT Landfill, Tseung Kwan O (TKO) Area 137 and Clear Water Bay Country Park (CWBCP).  For aquatic ecology, the Study Area also covered Fat Tong Tsui, Ti Cham Chau, Kwun Tsai and Tai Miu Wan.   

9.4                                      Literature Review of Ecological Characteristics of Study Area

9.4.1                                Methodology

A literature review was conducted to determine the existing ecological conditions within the Study Area as well as the associated aquatic habitats to identify habitat resources and species of potential importance.  The local literature reviewed included:

·            Porcupine! (Newsletter of Department of Ecology & Biodiversity, University of Hong Kong) ([2]);

·            AFCD Biodiversity Newsletters ([3]);

·            A Field Guide to the Terrestrial Mammals of Hong Kong ([4]).

·            Annual Reports of Hong Kong Bird Watching Society ([5]);

·            Hong Kong Amphibians and Reptiles ([6]) ;

·            A Field Guide to the Amphibians of Hong Kong ([7]);

·            A Field Guide to the Dragonflies of Hong Kong ([8]);

·            A Field Guide to Butterfly Watching in Hong Kong ([9]) ;

·            The Avifauna of Hong Kong ([10]);

·            Gymnosperms and Angiosperms of Hong Kong ([11]);

·            Orchidaceae of Hong Kong ([12]);

·            A Field Guide to the Venomous Land Snakes of Hong Kong ([13])

·            Ecological Study for SENT Landfill Extension - Final Report ([14]);

·            Further Development of Tseung Kwan O Feasibility Study ([15]);

·            SENT Landfill Study - Final Report ([16]); and

·            Field Guide to Hard Corals of Hong Kong ([17]).

·            SENT Operations and Environmental Monitoring Annual Report and Audit (from years 2003 to 2006) ([18]) .

9.4.2                                Results

Habitat and Vegetation

From the aerial photo taken in 2004 ([19]), habitats found within the Study Area included plantation, shrubland, grassland and disturbed/developed area.  Shrubland and grassland were found at the Extension Site within CWBCP (approximately 5.1 ha).  Plantation and developed areas were mainly found within the existing SENT Landfill.  Tseung Kwan O Area 137 is a newly reclaimed area located between the existing CWBCP, Fat Tong Chau and Tit Cham Chau.

An ecological study for the Extension undertaken in January 2003 ([20]) and covered only 3 ha of the area within the CWBCP.  The results indicated that the surveyed CWBCP area was a mosaic habitat of grassland and shrubland.  The area was rocky and scattered with bare ground especially in the middle of the hillsides.  Most of the plants recorded within the surveyed area were of 1 to 2m in height.  The grassland and shrubland mosaic consisted of 12 plant species, including: Rhodomyrtus tomentosa, Lygodium japonicum, Schefflera octophylla, Dicranopteris pedata, Phoenix hanceana, Miscanthus floridulus, Marcaranga tanarius, Inula cappa, Breynia fruticosa, Litsea rotundifolia, Cratoxylum cochinchinense and Scleria chinensis.  They were dominated by Dicranopteris pedata, Rhodomyrthus tomemtosa, Macaranga tanarius, Schefflera heptaphylla, Miscanthus sinensis and Miscanthus floridulus.  All of these plant species are commonly found in Hong Kong.

An ecological study for the Further Development of Tseung Kwan O ([21]) indicated that the habitats within the CWBCP (outside the Study Area of this EIA) are dominated by grassland/shrubland mosaic, with small patches of plantation at the valleys.  Plant species of conservation interest included the Yellow-eyed Grass Xyris indica.

SENT Operations and Environmental Monitoring reports for the period 2003 to 2006 ([22]) indicated that native plant species, including Celtis sinensis, Leucaena leucocephhala, Bidens bipinnata, Litsea rotundifolia, Triumfetta bartramia, Uraria crinita, Phyllodium pulchellum and Glochidon ericarpum, have been recorded within the SENT Landfill plantation , although exotic trees dominated the plantation. 

Terrestrial Mammals

Six terrestrial mammal species, including Wild Boar, Japanese Pipistrelle, Small Indian Civet, Palla’s Squirrel, Chestnut Spatial and Black Rat, were recorded in the Tseung Kwan O areas (Tseung Kwan O, Tiu Keng Leng and Hang Hau) ([23]) but no records are available for the Study Area.  All of the recorded mammal species are common and widespread in Hong Kong.  However, both Japanese Pipestrelle and Palla’s Squirrel are protected under the Wild Animals Protection Ordinance (Cap 170).  They were observed foraging in various habitats including shrubland, plantation and native secondary woodlands, including Hang Hau and CWBCP.

Birds

From the Ecological Study of SENT Landfill Extension - Final Report ([24]) and the Annual Report of Bird Watching ([25]), there were 47 species recorded in the existing SENT Landfill area and in the vicinity (including the Extension Site), these are shown in Table 1 of Annex D.  Most of the birds recorded were residential birds (eg bulbuls Pycnonotus spp. prinias Prinia spp.) or common visitors or migrants (eg Swifts Apus spp.). 

 

There were 6 Class II national protected species recorded in the Annual Report of Bird Watching Society, including the Pacific Reef Egret Egretta sacra, Black Bittern Dupetor flavicollis, Black-eared Kite Milvus lineatus, White-bellied Sea Eagle Haliaeetus leucogaster, Lesser Coucal Centropus bengalensis and Eurasian Eagle Owl Bubo bubo.

Herpetofauna

There is limited information on herpetofauna within the Study Area.

Seven amphibian and nine reptile species were recorded in the Tseung Kwan O area (but outside the Study Area of this EIA) during the Ecological Study of Further Development of Tseung Kwan O ([26]).  Most of the recorded species are common and widespread in Hong Kong, except Chinese Cobra (Naja atra) and Common Rat Snake (Ptyas mucosus) which are considered to be of conservation interest. 

Butterflies and Dragonflies

There is limited information on dragonfly and butterfly species within the Study Area.

There were 15 dragonfly and 44 butterfly species recorded in the Tseung Kwan O area (but outside the Study Area of this EIA) during the Ecological Study of Further Development of Tseung Kwan O ([27]).  The majority of the recorded species are common and widespread in Hong Kong, and none are considered to be of conservation interest. 

Stream Fauna

There is limited information on aquatic fauna within the Study Area.

Clear Water Bay Country Park

The CWBCP is located at the Clear Water Bay Peninsula, covering about 615 ha of natural habitats ([28]).  The CWBCP is dominated by shrubland, with small area of woodland and feng shui woods.  Plant species of conservation interest recorded in the CWBCP including the Chinese New Year Flowers, Wild Lily, Azaleas and species of orchid, such as Rattlesnake, Lady’s Slipper and Bamboo orchids.  The wildlife recorded in the CWBCP included bird species Francolin, Black Kite, Tree Sparrow, Chinese Bulbul, Greater Coucal, Great Tit and Japanese White-eye ([29]). 

Coral Communities

The underwater dive surveys conducted in 1999 and 2003, with findings presented in the Area 131 Further Ecological Study Report and the HATS Dive Survey Report respectively ([30]), indicated that Fat Tong Chau harboured very few hard corals (ie, Porites sp. and Cyphastrea sp.).  Nevertheless, soft corals and gorgonians including Echinomuricea sp., Euplexaura sp., Anthogorgia sp., Dendronephthya sp., Menella sp. and Echinogorgia sp., were frequent and occurred in moderate abundance.

As reported in the HATS coral dive surveys in 2003, in East Joss House Bay the coastal shallow areas had a rich community with 10 – 25% hard corals cover.  There was a total of 23 species hard coral recorded and Platygyra acuta was the most common hard coral.  However, there was relatively small amount of soft /gorgonian coral recorded at this location (<5% cover). 

The surveys in 2003 also indicated that there was low coral abundance (<5% cover) and diversity (8 species of hard coral and dominated by Cyphastrea seralia) recorded in the shallow coastal waters of West Joss House Bay. 

9.5                                      Identification of Information Gaps

9.5.1                                Introduction

Although there are some ecological baseline information available in the Tseung Kwan O area as well as the CWBCP, the current Study Area, in particular the additional 5.1 ha of the Extension Site within CWBCP, has limited information.  As a consequence, detailed ecological surveys in this area were required.

9.5.2                                Scope of Field Surveys

To supplement the limited available information, more than 9 months of terrestrial and aquatic ecology baseline surveys were conducted to collect baseline information of the Study Area.  The surveys were conducted during November 2005 to March 2006 (dry season) and April to July 2006 (wet season), which included habitat/vegetation, terrestrial mammal, bird, herpetofauna, invertebrates (butterfly and dragonfly) and stream fauna surveys for terrestrial ecology, and subtidal (dive) surveys along the coastal habitats in the close proximity to the Study Area, including Fat Tong Mun, Tit Cham Chau, Tai Miu Wan and Kwun Tsai.

9.6                                      Assessment Methodology

9.6.1                                Ecological Baseline Surveys

A reconnaissance survey was undertaken in October 2005 to update and field check the validity of the information gathered in the literature review.  A number of more focussed baseline field surveys were then identified and carried out to characterise the existing ecological conditions of the Study Area.  The surveys were designed to fill the data gaps identified in literature review.  Special attention was paid to the remaining natural habitats and those areas which will be directly impacted by the proposed Extension, especially the habitat and wildlife within the 5.1 ha of land to be developed into the CWBCP.  It should be noted that there were some limitations to take surveys within the existing SENT Landfill and TKO Area 137 due to safety concerns, and given that the areas are highly disturbed due to the busy traffic and the current working activities.

The following baseline ecological surveys were undertaken:

·            Terrestrial habitat and vegetation surveys;

·            Bird surveys (including night survey);

·            Mammal surveys (including night survey);

·            Invertebrates (butterflies and dragonflies) surveys;

·            Herpetofauna surveys (including night surveys);

·            Stream macro-fauna survey; and

·            Subtidal (dive) surveys.

Habitats and Vegetation

Habitat and vegetation surveys were performed on 17 November 2005, 12 December 2005, 24 February 2006, 16 March 2006 and 21 July 2006.  The aim of the surveys was to establish the ecological profile of habitat and vegetation within the Study Area.  A habitat map of the Study Area is shown in Figure 9.6a.

Habitats were mapped based on Government aerial photographs (year 2004)([31]) and field ground truthing.  Representative areas of each habitat type were surveyed on foot.  Plant species within each habitat type and their relative abundance were recorded with special attention to rare or protected species.  Nomenclature and conservation status of plant species follow Xing et al ([32]), Siu 2000 ([33]) and AFCD 2001 ([34]).

Terrestrial Mammal

Surveys of terrestrial mammals within the Study Area were conducted on 17 November 2005, 14 January, 24 February, 27 April, 26 May and 21 July 2006 to cover both dry and wet seasons.  Night surveys for mammals were carried out on 14 January and 21 July 2006.

As most mammals occur at low densities, all sightings, tracks, and signs of mammals were actively searched along the survey transects (see Figure 9.6b).  Nomenclature for mammals followed AFCD (2006) ([35]).  No quantification of abundance of mammals in the Study Area was made, due to the difficulties in translating sights and tracks (eg burrows) to actual abundance.

Birds

Habitats and areas of potential ecological importance for birds within the Study Area were identified in a reconnaissance survey.  Baseline surveys of bird populations were undertaken within those selected habitats using quantitative (point count) and qualitative (transect survey) methods.  Bird surveys were conducted on 17 November, 12 December 2005, 14 January, 27 April, 26 May and 29 June, 2006 to cover both dry and wet seasons.  Night surveys were conducted on 14 January 2006 and 26 May 2006.

Bird communities in each major habitat type recorded within the Study Area, including plantation, shrubland, grassland and disturbed/developed area were surveyed using the point count method.  A total of 18 sampling points at the Study Area were selected and their locations are shown in Figure 9.6b.  Ten minutes were spent counting birds at each sampling point.  All birds seen or heard within 30m of the sampling points were counted. 

Signs of breeding (eg nests, recently fledged juveniles) within the Study Area were also recorded.  Observations were made using 8x binoculars and photographic records were taken, if possible.  Bird abundance in each major habitat type was expressed in number of birds per hectare (total birds counted divided by total surveyed area). 
Bird species encountered outside counting points but within the Study Area were also recorded to produce a complete species list.  Signs of breeding (eg nests, recently fledged juveniles) were also recorded.  Ornithological nomenclature followed Carey et al ([36]).

Herpetofauna (Amphibians and Reptiles)

Surveys of herpetofauna within the Study Area were conducted on 17 November 2005, 14 January, 24 February, 27 April, 26 May and 21 July 2006 to cover both dry and wet seasons.  Night surveys of the amphibians were carried out on 14 January and 21 July 2006.  Herpetofauna surveys were conducted through direct observation and active searching in all major habitat types along the survey transects (see Figure 9.6b ) and in potential hiding places such as among leaf litter, inside holes and under stones and logs within the Study Area.  Auditory detection of species-specific calls was also used to survey frogs and toads.  During the surveys, all reptiles and amphibians sighted and heard were recorded.  Nomenclature and status used for reptiles follows Karen et al 1998 ([37]) while that of amphibians follows AFCD 2005 ([38]).

Invertebrate (Butterflies and Dragonflies) 

Surveys of butterfly and dragonfly species within the Study Area were conducted on 17 November 2005, 14 January, 24 February, 27 April, 26 May and 21 July 2006 covering both dry and wet seasons, along the survey transects (see Figure 9.6b).  Nomenclature for butterflies follows Yiu 2004 ([39]) and dragonfly nomenclature followed AFCD 2004 ([40]).

Stream Macro-fauna

Stream fauna surveys were undertaken on 17 November 2005, 26 May and 21 July 2006 to identify the water bodies and aquatic resources in the Study Area.  Streams identified within the Study Area were visited and stream fauna were studied by direct observation and active searching for sensitive species or individuals using hand nets. 

Subtidal Survey

 

In order to investigate the subtidal hard surface assemblages, as well as confirming the abundance and diversity of corals, along the coastlines potentially affected by the Landfill Extension, dive surveys in the form of Rapid Ecological Assessment (REA) ([41]) were conducted on 29 and 30 December 2005.  The REA technique allows semi-quantitative information on the ecological attributes of a subtidal habitat to be obtained relatively simply without compromising scientific rigour.  The survey was divided into five zones and each zone had one 100m transect, running parallel to the shoreline (see Figure 9.6c).  An initial qualitative reconnaissance surveys were conducted along the coastlines of Zones A to E.  During the survey, the position and number of transects were decided on site.  The preferred location would be having high coral abundance, or area of high epifaunal density.  The depth of transects was adjusted accordingly based on the substrate habitat and the presence or absence of hard and soft corals.

Zone A to E were surveyed referring to the Rapid Ecological Assessment.  Information was recorded by observers experienced in the field identification of sessile benthic taxa, swimming down-current at each location using SCUBA gear.  Transects were determined with a portable geographic positioning system (GPS) unit.  A 100m transect was laid out and video footage taken of the benthos along the transect/survey route followed by an assessment of the benthic cover (Tier I) and taxon abundance (Tier II) in a swathe ~ 4m wide, 2m either side of each transect.

Positioning: The exact location of each transect were determined with a portable Global Positioning System (GPS) unit and are provided in Table 9.6a.

Table 9.6a      Co-ordination of Survey Transects (Starting Point)

Transects

Easting

Northing

Latitude

Longitude

A1

114-15-57

22-16-45

845423

815581

B1

114-15-53

22-16-31

845327

815161

C1

114-16-38

22-15-45

846596

813732

D1

114-16-48

22-15-53

846884

813983

E1

114-17-2

22-16-11

847139

814531

Tier I - Categorisation of Benthic Cover

Upon the completion of each transect, seven substratum and six ecological attributes were assigned to one of seven standard ranked (ordinal) categories (Tables 9.6b and 9.6c).

Table 9.6b      Categories Used in the Surveys - Benthic Attributes

Ecological

Substratum

Hard coral

Hard substrate

Dead standing coral

Continuous pavement

Soft coral

Bedrock

Antipatharia

Rubble

Macroalgae

Sand

Turf algae

Silt

 

Boulders – large (>50cm), small (<50cm)

Table 9.6c      Categories Used in the Surveys - Ordinal Ranks of Percentage Cover

Rank

Percentage Cover (%)

0

None recorded

1

<5

2

6-10

3

11-30

4

31-50

5

51-75

6

76-100

Tier II - Taxonomic Inventories to Define Types of Benthic Communities

An inventory of benthic taxa was compiled during each dive (ie each transect).  Taxa were identified in situ to the following levels:

·           Scleractinian (hard) corals to species wherever possible;

·           Soft corals, anemones and conspicuous macroalgae were recorded according to morphological features and to genus level if possible; and

·           Other benthos (including sponges, zoanthids, ascidians and bryozoans) were recorded to genus level wherever possible but more typically to phylum plus growth form.

At the end of each dive, each taxon in the inventory was ranked in terms of abundance in the community (see Table 9.6d).  These broad categories rank taxa in terms of relative abundance of individuals, rather than the contribution to benthic cover along each transect.  The ranks are subjective assessments of abundance, rather than quantitative counts of each taxon.

Table 9.6d      Ordinal Ranks of Taxon Abundance

Rank

Abundance

0

Absent

1

Rare

2

Uncommon

3

Common

4

Abundant

5

Dominant

Photographs of representative coral species located in the surveyed areas were taken and, where possible, photographs of the seabed composition were taken.  Video footage and photographs are taken for all transects. 

9.6.2                                Assessment Methodology

The information presented in the following sections has been based on the findings of baseline surveys performed and the requirement of the EIA Study Brief (ESB-119/2004, Clause 3.4.7).  The importance of potentially impacted ecological resources identified within the Study Area was assessed using the EIAO-TM methodology.  The potential impacts (following the guideline of Annex 16 of the EIAO-TM) due to the construction, operation and restoration, and aftercare of the Extension were evaluated with respect to the criteria stipulated in Annex 8 in the EIAO-TM. 

9.7                                      Ecological Baseline Conditions

9.7.1                                Existing Terrestrial Habitat and Vegetation

The Study Area consisted of highly disturbed area (such as the TKO Area 137 and the existing SENT Landfill) at the south, west and north, and natural habitats (within CWBCP) at the east.  Terrestrial habitats found within the Study Area include plantation, shrubland, grassland, disturbed/ developed area and seasonal streams (see Figure 9.6a).  A narrow strip of sandy beach was also recorded at the south of the Study Area.  Colour photographs of all recorded habitat types, as well as other features and species of conservation interest, are presented in Figures 9.7a to 9.7g.  The photographs showing the current conditions of the proposed Extension Site are presented in Figure 9.7h.

A total of 124 plant species were recorded (see Table 2 of Annex D).  The number of plant species and the size of each identified habitat type are presented in Table 9.7a.

Table 9.7a      Habitat Types Recorded Within the Study Area

Habitat type

Area or Length

(hectare or m)

Number of Plant Species Recorded

Plantation

25.0 ha

14

Shrubland

75.3 ha

80

Grassland

19.7 ha

30

Disturbed/ Developed Area

171.2 ha

22

Seasonal Stream

154 m

12

Plantation

Exotic plantation was found at the north of the Study Area, within the boundary of the existing SENT Landfill.  A total of 14 plant species were recorded in the plantation and all of them are commonly found in Hong Kong.

The plantation is exotic woodland, dominated by the tree species Acacia confusa with a canopy height of 3 to 5m.  They were planted in the restored part of the existing SENT Landfill.  They are young in age and the understorey was sparsely occupied by weeds (expected to have invaded naturally), including Leucaena leucocephala, Bridelia tomentosa, Lantana camara and Miscanthus sinensis.  The plant species diversity and structural complexity of the plantation are considered to be low.  The photographic records of plantation are shown in Figure 9.7a.

Shrubland

Shrubland was found on the hill and mainly located within the CWBCP, in forms of continuous patch and comprised a total area of approximately 75.3 ha.  The shrubland has rocky substrate, and shows evidence of occasional disturbance by hill fires.  Shrubland patches found in the valleys are usually taller, with an average 2 to 3m in height, while those on the hill slopes are generally shorter, 0.3 to 1.5m in height.  A total of 80 plant species, which are commonly found in shrubland habitat in Hong Kong, were recorded.  The shrublands were dominated by several native shrub species, including Rhaphiolepis indica, Rhodomrytus tomentosa, Cratoxylum cochinchinensis, Eurya nitida, Embelia laeta, Embelia ribes and Gardenia jasminoides.  The species diversity of shrubland is considered to be moderate and the structural complexity is considered low to moderate.  The photographic records of shrubland are shown in Figure 9.7b.

Grassland

Grassland was recorded at the southeast of the Study Area, mainly located within the CWBCP, comprising 19.7 ha.  The grassland was found on the hill ridges with rocky substrate, and exposed to the winds.  It was disturbed by hill fires occasional.  A total of 30 grassy and shrubby plant species were recorded in the habitat and all of them are commonly recorded in Hong Kong.  The grassland was dominated by Ischaemum aristatum, Rhynchelytrum repens and Scleria harlandi, with shrub species Wikstroemia chinensis, Rhus succedanea and Mimosa pudica intermingled with each other.  The species diversity and structural complexity of grassland are considered to be low.  The photographic records of grassland are shown in Figure 9.7c.

Seasonal Stream

Two seasonal streams named S1 to S2 were recorded within the Study Area.  S1 (approximately 56m in length, with silty bottom) was located at Ha Shan Tuk and S2 (approximately 98m in length, with rocky bottom) was located at Hin Ha Au.  The photographic records of streams are shown in Figure 9.7d. Both of them are small seasonal streams with limited water flows during the wet season and no water flow during the dry season.  The riparian vegetation of the two seasonal streams was densely vegetated and intermingled with the shrubland vegetation in the close vicinity.  No stream fauna was recorded during the survey.  The ecological significance of these two seasonal streams therefore considered to be low.

Disturbed/ Developed Areas

Disturbed/developed area was the dominant habitat within the Study Area, comprising TKO Area 137, TKOIE and the existing SENT Landfill with a total area of approximately 171.2 ha.  The habitat was highly disturbed with limited vegetation cover and all the recorded plant species are common in Hong Kong and mainly for landscape purposes.  A total of 22 plant species, dominated by weeds and landscape species, such as Acacia auriculiformis and Leucaena leucocephala were recorded within the disturbed/ developed area.  The species diversity and structural complexity of the disturbed/ developed area are considered to be low.  The photographic records of the developed areas are shown in Figure 9.7e.

9.7.2                                Wildlife

Terrestrial Mammals

Four mammal species, including two bat species, Japanese Pipistrelle Pipistrellus abramus and the Brown Noctule Bat Nyctalus noctula, Tanezumi Rat Rattus tanezumi and Wild Boar Sus scrofa, were recorded within the Study Area (see Tables 3 and 4 of Annex D).  Only the Japanese Pipistrelle and Tanezumi Rat were recorded within the 5.1 ha of the Extension Site within the CWBCP.  All bats are protected in Hong Kong (Wild Animals Protected Ordinance Cap 170) but the two recorded bat species (Japanese Pipistrelle and the Brown Noctule Bat) are very common locally ([42]).  The locations of the two bats recorded during the surveys are shown in Figure 9.7f.  The other two mammal species are common, widespread in Hong Kong and without any conservation interest. 

Birds

Fifty-five bird species were recorded during the quantitative and qualitative surveys (see Table 5 of Annex D).  Four of them were recorded outside the survey points but within the Study Area.  Thirty-three species were recorded during the dry season and 36 species during the wet season (see Tables 6 and 7 of Annex D).  No birds were recorded during the night survey.  There were seven bird species of conservation interest, including Black Kite Milvus migran, Greater Coucal Centropus sinensis, Commom Buzzard Buteo buteo, Common Kestrel Falco tinnunculus, Hwamei Garrulax canorus, Brown Hawk Owl Ninox scutulata and White-bellied Sea Eagle Haliaeetus leucogaster, encountered during the surveys, and they were mainly perching or soaring in the sky within the Study Area.  With the exception of Hwamei, all of them are recognised as Class II protected species in the PRC.  White-bellied Sea Eagle and Hwamei are listed in CITES Appendix II.  The locations of bird species of conservation value are shown in Figure 9.7f.  Since the Black Kites were commonly found soaring in the sky within the Study Area, the exact locations of the bird were not shown.

Thirty of the species encountered were resident to Hong Kong.  Estimated bird abundance and the recorded numbers of bird species in major habitats are summarised in Table 9.7b.  The highest bird abundance and bird species were recorded at the shrubland.

Table 9.7b      Mean Abundance and Number of Bird Species in Different Types of Habitat in the Study Area

Habitat

Season

Plantation

Shrubland

Grassland

Disturbed/ Developed Area

Survey days

Dry

3

3

3

3

Wet

3

3

3

3

Overall

6

6

6

6

Number of individuals

Dry

65

280

57

90

Wet

49

148

97

66

Overall

114

428

154

156

Abundance (no. of individuals/ ha/survey point/survey day)

Dry

4.3

18.5

3.76

5.95

Wet

3.23

9.78

6.41

4.36

Overall

3.77

14.2

5.09

5.15

No. of species

Dry

19

26

15

17

Wet

14

20

21

17

 

Overall

26

33

28

24

Invertebrates

·           Butterflies:  A total of 50 species of butterflies were recorded during the surveys (see Table 8 of Annex D).  Thirty-three of which were recorded in the dry season and 34 in the wet season (see Tables 9 and 10 of Annex D).  Grassland habitats have the highest number of butterfly species recorded (23 out of the 50 species) in the wet season while shrubland has the highest number of butterfly species in the dry season (21 out of the 50 species).   Grassland was also recorded to have the highest number of individual butterflies for both the dry and wet seasons.  The number of butterfly species and total number of individuals recorded in each habitat of the Study Area are summarised in Table 9.7c.

Table 9.7c      Butterfly Species Recorded in Each Habitat of the Study Area

Habitat

Season

Plantation

Shrubland

Grassland

Disturbed/ Developed Area

No. of species

Dry

9

21

14

11

 

Wet

14

17

23

2

 

Overall

 

 

 

 

No. of individuals

Dry

15

75

110

65

Wet

98

101

178

3

Overall

113

176

288

68

No. of uncommon species

 

 

5

2

 

No. of rare species

 

 

3

3

 

Among the 50 butterfly species, 6 are uncommon, 5 are rare species and the rest are either common or abundant in Hong Kong (Table 9.7d).  None of them have protection status.  Six uncommon species include Toothed Sunbeam Curetis dentate, Small Grass Blue Famegana alsulus, Indian Palm Bob Suastus gremius, Common Nawab Polyura athamas, Indian Fritillary Argyreus hyperbius and White-edged Blue Baron Euthalia phemius.  Rare species are Common Dart Potanthus pseudomaesa, Grass Demon Udaspes folus, Dark Grass Blue Zizeeria karsandra, Swallowtail Papilio xuthus and Lesser Band Dart Pothanthus trachala.  The locations of butterfly species of conservation interests recorded within the Study Area are shown in Figure 9.7f. 


Table 9.7d      Larval Food Plants of Butterfly Species of Conservation Interests

Common Name

Species Name

Status

Food Plant as Reported in Bascombe et al 1999 ([43])

Grass Demon

Udaspes folus

Rare

Zingiber officinale, Hedychium coronarium

Common Dart

Potanthus pseudomaesa

Rare

Cymbopogon tortilis, Miscanthus floridulus

Lesser Band Dart

Potanthus trachala

Rare

Ischaemum indicum, Miscanthus floridulus, M. sinensis, Phragmites karka

Swallowtail

Papilio xuthus

Rare

Zanthoxylum nitidum, Z. myriacanthum, Citrus microcarpa, Fortunellla hindsii, F japonica

Dark Grass Blue

Zizeeria karsandra

Rare

Amaranthus spinosus, A. tricolor, A. viridis

Indian Palm Bob

Suastus gremius

Uncommon

Phoenix hanceana, P. roebelinii, Rhapis excelsa

Toothed Sunbeam

Curetis dentate

Uncommon

Millettia reticulata, Pongamia pinnata

Small Grass Blue

Famegana alsulus

Uncommon

Desmodium elegans, Flemingia macrophylla, Phyllodium pulchellum

Common Nawab

Polyura athamas

Uncommon

Acacia sinuate, Albizia corniculata, A. lebbeck, Archidendron clypearia, Leucaena leucocephala

Indian Fritillary

Argyreus hyperbius

Uncommon

Viola betonicifolia, V. odorata

White-edged Blue Baron

Euthalia phemius

Uncommon

Mangifera indica

·            Dragonflies:  Six dragonfly species including Common Bluetail, Amber-winged Glider, Common Blue Skimmer, Common Red Skimmer, Green Skimmer and Wandering Glider were recorded in the Study Area during the survey (see Tables 11 to 13 of Annex D).  All of the dragonfly species are abundant or commonly found in Hong Kong. 

Grassland has the highest number of individuals of dragonflies while disturbed/developed area and plantation has the highest number of species during the survey.  The number of dragonfly species and total number of individuals recorded in each habitat are summarised in Table 9.7e.

Table 9.7e      Dragonfly Species Recorded in Each Habitat of the Study Area

Habitat

Season

Plantation

Shrubland

Grassland

Disturbed/ Developed Area

No. of species

Dry

 

2

 

3

 

Wet

3

2

2

3

 

Overall

3

3

2

4

No. of individuals

Dry

 

31

 

3

 

Wet

17

15

36

5

 

Overall

17

46

36

8

Herpetofauna

A total of five species of amphibian (Asian Common Toad, Gunther’s Frog, Paddy Frog, Brown Tree Frog and Ornate Pygmy Frog), two species of reptiles (Changeable Lizard and Common Rat Snake) were recorded in the Study Area (see Tables 14 to 16 of Annex D).  The location of the common and widespread reptile, but listed in CITES Appendix II, the Common Rat Snake Ptyas mucosus was presented in Figure 9.7f.  The remaining species are common locally. 

Stream Macro-fauna

No aquatic fauna was recorded within the seasonal streams, which may be due to the limited water flow during the surveys.

9.7.3                                Sub-tidal Habitat

Seabed condition

The survey was performed on 29 and 30 December 2005.  The weather was sunny and the sea was calm.  The visibility was poor, ranging between 0.5m and 1.5m.  The photographic records of the sub-tidal dive habitats are shown in Figure 9.7g.  The results of the qualitative survey are shown in Table 17 of Annex D.  Along each transect the seabed composition was identified and conditions were shown in Table 18 of Annex D.  The seabed attributes of the transects are shown in Table 19 of Annex D.

Coral Assemblages

A total of nineteen species of hard coral and five species of soft coral were recorded along the survey transects and in their vicinity.  All of them are commonly found in Hong Kong except the hard coral species Acropora solitaryensis which is uncommon in Hong Kong.  The relative positions and estimated sizes (soft coral in length while hard coral in diameter) of the hard and soft corals are listed in Table 20 of Annex D.  The relative abundance (percentage cover) of each hard coral species at Transects A1 to E1 are shown in Table 9.7f and the relative abundance of soft corals are shown in Table 9.7g.

Table 9.7f       Hard Coral Species Recorded in Transects A1 – E1

Hard Coral Species

Percentage Cover

A1

B1

C1

D1

E1

Acropora solitaryensis

-

-

-

1

-

Coscinaraea n sp.

1

1

-

-

1

Cyphastrea serailia

-

-

1

-

-

Favia favus

1

-

-

-

1

Favia lizardensis

-

-

-

-

1

Favia rotumana

-

-

-

-

1

Favia speciosa

-

-

1

1

1

Favites abdita

-

-

1

1

-

Goniastrea aspera

1

-

-

1

-

Goniopora stutchburyi

-

1

-

-

1

Hydnophora exesa

1

-

-

-

-

Leptastrea purpurea

-

-

-

1

-

Oulastrea crispata

-

-

1

-

1

Pavona decussata

-

-

-

1

-

Platygyra acuta

-

-

-

1

-

Plesiastrea versipora

1

1

1

1

1

Porites sp.

1

1

1

1

-

Psammocora superficialis

1

-

1

1

1

Turbinaria peltata

-

-

1

1

-

Total Number of Species

7

4

8

11

9

Note:

(a)     1 = 1-10% Cover, 2 = 11-30% Cover, 3 = 31-50% Cover, 4 = 51-75% Cover, 5 = 76-100% cover.

Table 9.7g      Soft Coral Species Recorded in Transects A1 – E1

Soft Coral Species

Percentage Cover

A1

B1

C1

D1

E1

Cladiella sp.

1

-

-

-

-

Dendronephtha sp.

-

1

-

-

-

Echinomuricea sp.

3

-

-

-

-

Euplexaura sp.

2

1

1

-

-

Tubastrea sp.

1

-

-

-

-

Total Number of Species

4

2

1

0

0

Note:

(a)        1 = 1-10% Cover, 2 = 11-30% Cover, 3 = 31-50% Cover, 4 = 51-75% Cover, 5 = 76-100% cover. 

 

The benthic fauna recorded along the survey transect included sponges, ascidians, rock oyster Saccostrea cucullata, Pinctada sp., the sea cucumber Holothuria leucospilota, decorator urchins Temnopleura reevesi, sea urchin Anthocidaris crassispina and the long-spined sea urchins Diadema setosum. 

The results of the sub-tidal habitat surveys indicated that hard corals were in low abundance and diversity, and dominated by species which are commonly found in Hong Kong.  Zone A found to have relatively high abundance of soft coral and dominated by Echinomuricea sp. and Euplexaura sp. which are quite common in Hong Kong.  The ecological values of the sub-tidal habitats are considered to be low to moderate.

9.7.4                                Existing Conditions of the Extension Site

The Extension Site comprised part of the TKO Area 137, the existing SENT Landfill and the CWBCP area.  Based on the literature review and the field surveys, it was found that the habitats recorded in the Extension Site are dominated by disturbed/developed areas (34.6 ha) and plantation (12.2 ha), with small patches of shrubland (6 ha) and grassland (0.1 ha).  For the areas within the CWBCP, 5.1 ha of the existing habitats, including approximately 4.6 ha of shrubland, 0.1 ha of grassland and 0.4 ha of disturbed/developed areas will be affected.  The photographic records of habitats within the Extension Site are shown in Figure 9.7h.

Plantation was recorded within the existing SENT Landfill, which is dominated by exotic plants Acacia auriculiformis with a height of 3 to 5m.   The under-storey was sparsely occupied by weeds and native shrubs, dominated by Leucaena leucocephala, Rhus succedanea Rhaphiolepis indica and Ficus microcarpa.  The species diversity and structural complexity of the plantation are considered to be low.

The shrubland was dominated by native shrubs at a height of 1.5 to 2m, with native shrubs such as Breynia fruticosa, Bridelia tomentosa, Cratoxylum cochinchinensis and Rhodomrytus tomentosa.  The species diversity of the shrubland is considered as moderate and the structural diversity to be low to moderate.

The grassland was dominated by grasses and sedges including Miscanthus sinensis and Rhynchelytrum repens at a height of 0.5 to 1m.  The species diversity and the structural complexity of grassland are considered as low.

The disturbed/developed area is highly disturbed by human activities and limited vegetation cover was recorded.  The vegetation was dominated by sedges and climbers such as Cyperus rutondus, Leucaena leucocephala and Mikania micrantha and plants for landscape purposes (see Table 2 of Annex D).   The species diversity and structural complexity of the disturbed/developed area are considered to be low. 

A total of 88 plant species were recorded within the Extension Site, in which 62 plant species were recorded within the 5.1 ha of the Extension Site within the CWBCP.  All of the recorded plant species are common or very common in Hong Kong. 

The results of the field surveys indicated that the wildlife abundance and species diversity recorded within the Extension Site were relatively low in the plantation and developed areas, but moderate in shrubland and grassland.  The species diversity and wildlife abundance recorded within the CWBCP area were low to moderate in the shrubland.  Species of conservation interests found within the Extension Site are shown in Table 9.7h.

Table 9.7h      Faunal Species with Ecological Interest within the Extension Site

Species

Location

Activity

Protection Status

Mammals

 

 

 

Japanese Pipistrelle Pipistrellus abramus

Shrubland within the encroached area of CWBCP and developed area of the Extension Site

Soaring

Wild Animals and Plants (Cap 170)

Brown Noctule Bat Nyctalus noctula

Developed area within the Extension Site

Flying fast above the habitat

Wild Animals and Plants (Cap 170)

 

Birds

 

 

 

Black Kite Milvus lineatus

Shrubland, developed area and plantation within the Extension Site, and shrubland within the encroached area of the CWBCP

Soaring

Class 2 Protected Animal of PRC;

 

Common Buzzard

Buteo buteo

Shrubland within the encroached area of the CWBCP

Perching, flight over

Class 2 Protected Animal of PRC;

Greater Coucal Centropus sinensis

Developed area within the Extension Site

Perching

Class 2 Protected Animal of PRC

Brown Hawk Owl Ninox scutulata

Shrubland within the encroached area of the CWBCP

 

Perching

Class 2 Protected Animal of PRC

Butterflies

 

 

 

Swallowtail Papilio xuthus

Shrubland near the top of the hill within the encroached area of the CWBCP

Flying over

Not protected

Indian Fritillary Argyreus hyperbius

Shrubland near the top of the hill within the encroached area of the CWBCP

Flying over

Not protected

Toothed Sunbeam Curetis dentate

Shrubland within the encroached area of CWBCP.

Flying over

Not protected

White-edged Blue Baron Euthalia phemius

Shrubland within the encroached area of the CWBCP

Flying over

Not protected

Reptiles

 

 

 

Common Rat Snake Ptyas mucosus

Shrubland within the encroached area of the CWBCP

Resting

Not protected in Hong Kong;

CITES Appendix II

In conclusion, the ecological value of shrubland is considered to be moderate, low to moderate for grassland, low for plantation and negligible for the disturbed/developed area. 

9.8                                      Ecological Evaluation

In this section the ecological importance of the habitats and wildlife identified within the Study Area are evaluated in accordance with the criteria stipulated in Annex 8 of the EIAO-TM.  The evaluation is based upon the information presented in Section 9.7.  The ecological importance of each habitat type within the Study Area and the habitats within the Extension Site are presented in Tables 9.8a to 9.8g.

 

Table 9.8a      Ecological Evaluation of Plantation

Criteria

Plantation

Naturalness

Man-made habitat dominated by exotic plants.

Size

Exotic plantation with the overall size of 25.0 ha.  Approximately 12.2 ha of plantation located within the Extension Site. 

Diversity

Low diversity of plant (14 species), low diversity of birds (26 species), butterfly (18 species) and other fauna.

Rarity

Bird species Black Kite was recorded soaring in the sky.

Re-creatability

Habitat characteristics and species composition are easy to recreate.  It will take around 5 to 10 years for the plantation to be re-created.

Fragmentation

Not applicable.

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity.

Potential Value

Low

Nursery/ Breeding Ground

None.

Age

Young (10 years) based on tree size, woodland structure and species composition.

Abundance/ Richness of Wildlife

Low abundance for wildlife.

Overall Ecological Value

Low

 


Table 9.8b      Ecological Evaluation of Shrubland

Criteria

Shrubland

Naturalness

Natural habitat with disturbance of hill fires

Size

Shrubland has the overall size of approximately 75.3 ha.  Approximately 6 ha of shrubland were found within the Extension Site in which approximately 4.6 ha located within the CWBCP and outside of the existing SENT Landfill.

Diversity

Moderate for vegetation (totally 80 species for the whole area, mostly native shrubs and climbers), moderate for faunal diversity

Rarity

Species of conservation interest included Japanese Pipistrelle, Black Kite, Brown Hawk Owl, Common Buzzard, Greater Coucal, Hwamei, Common Rat Snake, Lesser Band Dart, Swallowtail, Common Nawab, Common Dart, Indian Fritillary, Toothed Sunbeam, White-edged Blue Baron and Indian Palm Bob

Re-creatability

Habitat characteristics and species composition are easy to recreate.  It will take more than 10 years for the shrubland to be re-created.

Fragmentation

Shrubland mainly exists as a continuous patch

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity

Potential Value

Medium to high

Nursery /Breeding Ground

No significant nursery/breeding ground recorded.

Age

Young to moderate

Abundance/ Richness of Wildlife

Moderate for avifauna and butterflies, low for dragonfly

Overall Ecological Value

Moderate

Table 9.8c      Ecological Evaluation of Grassland

Criteria

Grassland

Naturalness

Semi-natural, disturbed by hill fire and dominated by grasses and sedges

Size

Grassland was approximately 19.7ha, with 0.1 ha encroached within the CWBCP and outside the existing SENT Landfill

Diversity

Low for vegetation and low to moderate for fauna

Rarity

Species of conservation interests included Black Kite, Hwamei, Common Buzzard, Common Kestrel, White-bellied Sea Eagle, Dark Grass Blue, Small Grass Blue, Lesser Band Dart and Grass Demon

Re-creatability

Readily creatable

Fragmentation

Not applicable

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity

Potential Value

Low

Nursery/ Breeding Ground

No significant nursery/breeding ground recorded

Age

Young

Abundance/ Richness of Wildlife

Wildlife abundance was low to moderate

Overall Ecological Value

Low to moderate

Table 9.8d      Ecological Evaluation of Seasonal Streams

Criteria

Seasonal Stream S1 at Tin Ha Au

Seasonal Stream S2 at Tin Ha Au

Naturalness

Natural

Natural

Size

The total length was 56 m with silty substratum

The total length was 98 m with rocky substratum.

Diversity

Low for plant and no aquatic fauna recorded

Low for plant and no aquatic fauna recorded

Rarity

Nil

Nil

Re-creatability

Re-creatable

Re-creatable

Fragmentation

Not applicable

Not applicable

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity

Not functionally linked to any highly valued habitat in close proximity

Potential Value

Low ecological potential

Low ecological potential

Nursery/Breeding Ground

None

None

Age

Not applicable

Not applicable

Abundance/

Richness of Wildlife

Nil

Nil

Overall Ecological Value

Low

Low

Table 9.8e      Ecological Evaluation of Disturbed/ Developed Area

Criteria

Disturbed / Developed Area

Naturalness

Man-made habitat

Size

The overall size was approximately 171.2 ha.  This habitat was dominant within the Extension Site with approximately 34.6 ha.  0.4 ha of this habitat is located within the encroached area of CWBCP.

Diversity

Low for flora and fauna.

Rarity

Species of conservation interests included Japanese Pipistrelle, Brown Noctule Bat, Black Kite and Greater Coucal

Re-creatability

Readily re-creatable

Fragmentation

Not applicable

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity

Potential Value

Low

Nursery/Breeding Ground

None

Age

Not applicable

Abundance/Richness of Wildlife

Low

Overall Ecological Value

Negligible

Table 9.8f       Ecological Evaluation of Subtidal Habitats

Criteria

Subtidal Habitats

Naturalness

Natural

Size

Overall 500 m of survey transects were done for Zones A to E.  None of the subtidal habitats were found within the Project Site.

Diversity

Hard corals were in low abundance and diversity. Zone A found to have relatively high abundance of soft coral

Rarity

Uncommon coral species Acropora solitaryensis.

Re-creatability

The subtidal habitat may take 5 to 10 years to re-establish.

Fragmentation

Not applicable

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity

Potential Value

Low

Nursery/Breeding Ground

None

Age

Not applicable

Abundance/Richness of Wildlife

Low

Overall Ecological Value

Low to moderate

Table 9.8g      Ecological Evaluation of the Extension Site

Criteria

Extension Site

Naturalness

Dominated by man-made habitat (disturbed/developed area and plantation).  Natural habitats included shrubland and grassland but with certain degree of disturbance (ie, hill fire) were recorded.

Size

Approximately 34.6 ha of disturbed/ developed area, 12.2 plantation, 6 ha of shrubland and 0.1 ha of grassland recorded within the Extension Site.  4.6 ha of shrubland, 0.1 ha of grassland and 0.4 ha of disturbed/developed area were encroached upon the CWBCP.

Diversity

Low to moderate for vegetation and fauna

Rarity

Species of conservation interest included Japanese Pipistrelle, Brown Noctule Bat, Black Kite, Greater Coucal, Brown Hawk Owl, Common Buzzard, Common Rat Snake, Swallowtail, Tooted Sunbeam, White-edged Blue Baron and Indian Fritillary

Re-creatability

The shrubland may take 10 years to be recreated, plantation may take 10 years to be recreated, grassland may take 5 years to re-created

Fragmentation

Not applicable

Ecological Linkage

Not functionally linked to any highly valued habitat in close proximity

Potential Value

Low

Nursery/Breeding Ground

No significant nursery/breeding ground recorded

Age

Young

Abundance/Richness of Wildlife

Abundance and richness of wildlife was low. 

Overall Ecological Value

Low to moderate

The lists and evaluations of the floral and faunal species of ecological interest recorded within the Study Area, according to the EIAO-TM, are given in Table 9.8h.

Table 9.8h      Evaluation of Faunal Species with Ecological Interest within the Study Area

Species

Location

Protection Status

Distribution

Rarity

Mammals

 

 

 

 

Japanese Pipistrelle Pipistrellus abramus

Shrubland and disturbed/developed area within Study Area and the shrubland encroached within the CWBCP

Wild Animals and Plants (Cap 170)

Widespread

Very Common

Brown Noctule Bat Nyctalus noctula

Flying fast above the developed area within the Study Area

Wild Animals and Plants (Cap 170)

Scattered records in New Territories and Lantau

Common

Birds

 

 

 

 

White-bellied Sea Eagle

Haliaeetus leucogaster

Flying above the grassland of Study Area, perching

Class 2 of Protected Animal of PRC; Appendix 2 in CITES

Found in coastal area of Hong Kong, Oriental and Australasian

An uncommon resident in HK

Black-eared Kite Milvus lineatus

In various habitats of the Study Area; Soaring

Class 2 Protected Animal of PRC

 

Found in many types of habitats;

East Eurasia

Common and widespread in HK

Common Kestrel Falco tinnunculus

Recorded in flight over grassland of Study Area, perching

Class 2 Protected Animal of PRC

Widespread in China; Eurasian and African

Common and widespread autumn migrant, less common winter visitor

Common Buzzard

Buteo buteo

Recorded in flight over shrubland within the encroached area of CWBCP and grassland within the Study Area, perching

Class 2 Protected Animal of PRC

Widespread in Eurasia

Common winter visitor to HK

Greater Coucal Centropus sinensis

Recorded in disturbed/developed area of the Study Area, perching

Class 2 Protected Animal of PRC

Found in many types of habitats in Hong Kong;

Oriental

Common and widespread in HK;

Very rare in China

Hwamei Garrulax canorus

Recorded in grassland of the Study Area, perching

Appendix 2 in CITES

Found in shrubland in Hong Kong

An uncommon resident in HK; uncommon in China

Brown Hawk Owl Ninox scutulata

In shrubland within the encroached area of CWBCP, perching

Class 2 Protected Animal of PRC

Can turn up in various vegetated habitats during migration, Oriental

Very rare passage migrant in HK

Butterflies

 

 

 

 

Common Dart Potanthus pseudomaesa

Shrubland within the encroached area of CWBCP

Not protected

Found in Hok Tau, Uk Tau, Ma On Shan and Victoria Peak

Rare

Grass Demon Udaspes folus

Grassland in the valley within the Study Area

Not protected

Found in most country parks

Rare

Lesser Band Dart Potanthus trachala

Grassland within the Study Area and the shrubland at the southern part of the Study Area

Not protected

Found in most country parks

Rare

Swallowtail Papilio xuthus

Shrubland near the top of the hill within encroached area of CWBCP

Not protected

Ma On Shan, Plover Cove, Tai Tam, Tai Lam, Pat Sin Leng, Sha Lo Wan, Kat O, Lung Kwu Tan

Rare

Dark Grass Blue Zizeeria karsandra

Grassland within the Study Area

Not Protected

Most country parks

Rare

Common Nawab Polyura athamas

Shrubland near the top of the hill within the Study Area

Not protected

Most country parks

Uncommon

Indian Fritillary Argyreus hyperbius

Shrubland near the top of the hill within the encroached area of CWBCP and the shrubland at the southern part of the Study Area

Not protected

Found in most country parks

Uncommon

Indian Palm Bob Suastus gremius

Shrubland near the top of the hill within the Study Area

Not protected

Found in most country parks

Uncommon

Small Grass Blue Famegana alsulus

Grassland along the ridge within the Study Area

Not protected

Plover Cove. Sai Kung West Country Park, Pokfulam, Lamma

Uncommon

Toothed Sunbeam Curetis dentate

Shrubland within the encroached area of CWBCP

Not protected

Most country parks

Uncommon

White-edged Blue Baron Euthalia phemius

Shrubland within the encroached area of CWBCP

Not protected

Found in most country parks

Uncommon

Reptiles

 

 

 

 

Common Rat Snake Ptyas mucosus

Shrubland near the top of the hill within the encroached area of CWBCP

Not protected in Hong Kong;

CITES Appendix II

Widespread in HK

Common

Corals

 

 

 

 

Acropora solitaryensis

Shore of Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Predominant distribution in the southeastern sector of Hong Kong's coastal waters.

Uncommon

Coscinaraea n sp.

Shore of Fat Tong Chau and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

In northeastern, eastern, southeastern and western waters of Hong Kong. 

Common

Cyphastrea serailia

Shore of Tit Cham Chau

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Dominant

Favia favus

Shore of Fat Tong Chau and Tit Cham Chau

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Favia lizardensis

Shore of Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Common

Favia rotumana

Shore of Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Favia speciosa

Shore of Tit Cham Chau, Kwun Tsai and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Favites abdita

Shore of Tit Cham Chau and Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Dominant

Goniastrea aspera

Shore of Fat Tong Chau and Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Common

Goniopora stutchburyi

Shore of Fat Tong Chau and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Common

Hydnophora exesa

Shore of Fat Tong Chau

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Leptastrea purpurea

Shore of Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Oulastrea crispata

Shore of Tit Cham Chau and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Common

Pavona decussata

Shore of Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Platygyra acuta

Shore of Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Dominant

Plesiastrea versipora

Shore of Fat Tong Chau, Tit Cham Chau, Kwun Tsai and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Porites sp.

Shore of Shore of Fat Tong Chau, Tit Cham Chau and Kwun Tsai

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Porites sp. recorded in Hong Kong included Porites lobata, Porites lutea, Porites aranetai, Porites deformis and Porites solida.  They are wildspread in Hong Kong, especially the east and northeastern waters. 

Porites sp. recorded in Hong Kong included Porites lobata, Porites lutea, Porites aranetai, Porites deformis and Porites solida. All of the species are common or abundantly found in Hong Kong except Porites aranetai and Porites deformis are uncommon and Porites solida is rare. 

Psammocora superficialis

Shore of Fat Tong Chau, Tit Cham Chau, Kwun Tsai and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Abundant

Turbinaria peltata

Shore of Tit Cham Chau and Tin Ha Au

Protection of Endangered Species of Animals and Plants Ordinance (Cap 586), Marine Park Ordinance (Cap 476)

Widespread in Hong Kong

Common

9.9                                      Potential Impacts and Impact Assessment

The construction of the Extension involves removal of vegetation and land excavation for the construction of desired landform.  The construction works are expected to be completed within 2 years and the operation/restoration period will last for about 6 years.  The aftercare period for the Extension is estimated to last up to 30 years.  During the Aftercare period, the landfill contractor will continue to manage the final cap (including the vegetation of top of the cap) and the leachate and landfill gas generated from the Extension.

9.9.1                                Construction Phase

The potential ecological impacts due to the construction of the Extension are described below. 

Habitat Loss

·           Permanent loss of plantation (approximately 12.2 ha), shrubland (approximately 1.4 ha) and disturbed/developed area (approximately 34.2 ha) within the existing SENT Landfill and TKO Area 137 during construction of the Extension Site;

·           Permanent loss of shrubland (approximately 4.6 ha), grassland (approximately 0.1 ha) and disturbed/developed area (approximately 0.4 ha), which are located within the CWBCP and outside the existing SENT Landfill, due to the construction of the Extension;

·           Loss of foraging and feeding ground of the associated wildlife, particularly the natural habitats; and

·           No direct loss of subtidal habitats is expected as it is a land based project that no marine works would be involved and no marine habitat/species would be affected.

Details are presented in Figure 9.9a and Table 9.9a.

Table 9.9a      Overall Habitat Loss due to the Construction of the Extension

Impacted Habitats

Permanent Loss (ha)

Ecological Value of the Affected Habitat

Plantation

12.2

Low

Shrubland

6 (4.6 ha)

Moderate

Grassland

0.1 (0.1 ha)

Low to moderate

Disturbed/ Developed Area

34.6 (0.4 ha)

Nil

Note:

(a)        Habitats located within the CWBCP and outside the existing SENT Landfill to be affected are presented in bracket.

Impacts to Wildlife

·           Reduction of wildlife species abundance/diversity and ecological carrying capacity is expected to be minimal due to the loss of a relatively small area of natural habitat (as compared with the large extent of similar habitats in the immediate vicinity), and steep slope of the affected area limits the wildlife usage.  Although species of conservation interest including Japanese Pipistrelle, Brown Noctule Bat, Greater Coucal, Brown Hawk Owl, Common Buzzard, Black Kite, Common Rat Snake, Swallowtail, Tooted Sunbeam, White-edged Blue Baron and Indian Fritillary were recorded within the Extension Site, the majority of the Extension Site is not the preferred habitat of these species. 

·           Impacts to wildlife with high mobility such as birds, butterflies, dragonflies and herpetofauna is expected to be minimal as there is relatively large area of similar natural habitats in the close vicinity.  Impacts to wildlife with low mobility such as insects will be a concern as the loss of habitat may reduce their abundance and diversity.  However, with the compensatory planting of mixed woodland and shrubland, the impacts to wildlife is expected to be minimal.

·           The impacts due to the loss of foraging ground are also considered to be minimal given that the large extent of similar habitats in the vicinity, and the affected areas located next to the currently highly disturbed areas.

·           Given that there was no aquatic fauna recorded in the seasonal streams and cut-off channel will be effectively operated to avoid any discharge outside the Extension Site prior to the extension works, impacts to aquatic life (in particular corals in the surrounding coastal areas) due to the change in water quality, sedimentation rate and pattern is expected to be minimal.

Habitat Fragmentation and Isolation

·           Habitat fragmentation and isolation are not expected as the majority of the affected habitats are either disturbed or located next to the developed areas, and the natural habitats (mainly shrubland) are located at the western end of the headland and most of the upland and surrounding habitats will remain untouched.  It should be noted that the areas within the CWBCP are generally steep and are expected to be mainly utilized by highly mobile wildlife such as birds and butterflies, which are less affected by such fragmentation and isolation effects.

Other Impacts

·           As no streams or water gathering areas will be affected due to the Extension, and no marine works are involved, the hydrology and hydrodynamic properties would not be affected.

·           During the first year of construction, works including site formation and construction of site office buildings, workshops, landfill gas and leachate treatment plant will be carried out.  Excavation is necessary for the construction of the new infrastructure.  It is anticipated that, with the implementation of good construction practices, as stated in ProPECC PN1/4, and appropriate mitigation measures including provision of a perimeter cut-off channel around the Extension Site, intercepting channels and silt removal facilities (see Section 6.8), contamination of construction runoff will be minimal and there will be no unacceptable water quality and ecological impacts to the receiving water bodies (ie surface water including two seasonal streams S1 and S2, inshore waters in Junk Bay and Joss House Bay, as well as the coral communities recorded in the subtidal habitats along the coastlines in particular at Kwun Tsai where the uncommon coral species Acropora solitaryensis recorded).

·           The base of the landfill (either existing SENT Landfill or the Extension) has been designed to be above the groundwater level (see Section 3), the hydrogeology of the area is not expected to be influenced.

·           The blasting works which generate very short-term instantaneous impacts, may affect the wildlife, in particular birds, associated with the natural habitats in the immediate vicinity.  It should be noted that the quantity of explosive used and the dimensions and spacings of shotholes will be carefully designed to minimise air overpressure, flyrock generation and ground-borne vibration.  The loose material and stones in the site will be removed before blasting to minimise the potential for flying fragments to affect the surrounding areas.  The blasting area will also be wetted prior to blasting to minimise dust generation.  With the use of fine blast nets, screens and other protective covers, the impacts to the wildlife associated with the surrounding habitats due to blasting are expected to be low.  It should be noted that the formation of rock slopes of the existing SENT Landfill adopted similar blasting works.  No adverse ecological impacts were observed due to the blasting works.

·           Secondary impacts to the surrounding habitats (generally with low to moderate ecological value, including the sub-tidal habitats in the vicinity) and associated wildlife may arise from the potential for increased noise impact, human activities and disturbance such as hill fire, import, storage or dumping of construction materials and construction site runoff.  The impacts are expected to be low owing to the existing disturbed nature of the majority of the site, and given that regular site audits on good construction practice (including the provision of chain-link fence around the site boundary to restrict construction activities within the site boundary) and surface water management systems will be employed during the construction phase.

9.9.2                                Operation/Restoration Phase

 

The operation and restoration of the Extension will be implemented concurrently.  The main ecological concern during this phase is related to the accidental leakage of leachate, other wastewaters and landfill gas, which may result in:

·       potential impacts to water quality and aquatic life particularly corals in the vicinity due to leakage of leachate and wastewater; and

·      potential impacts to the surrounding natural habitat in CWBCP and associated wildlife due to an accidental fire caused by accidental leakage of landfill gas.

With the incorporation of well designed and properly implemented pollution control measures and systems, including landfill gas management system, leachate management system and surface water/groundwater system (see Section 3), as well as implementing a comprehensive environmental monitoring and audit programme, accidental discharge of leachate into surface water, and subsurface off-site migration of leachate and landfill gas will be adequately controlled and the associated impacts to the surrounding natural habitats, associated wildlife and aquatic life particularly corals in the vicinity are not expected.

Operation/restoration phase impacts to terrestrial ecology may arise from increased human activities in the area resulting in disturbance to the surrounding natural habitats in CWBCP and associated wildlife, if uncontrolled.  Chain-link fence or boundary wall will be erected around the Extension Site boundary to restrict the construction and operation/restoration activities within the site boundary.  Given that general wildlife including species of conservation interest can still be observed around the area of the existing SENT Landfill during the ecological baseline surveys for this EIA it is not expected that unacceptable operation/restoration phase impacts will occur. 

9.9.3                                Aftercare Phase

The aftercare phase will begin when the final filling and restoration of the Extension are completed, and is estimated to last up to 30 years.  The works to be performed during this aftercare period will include maintaining the control measures and systems functioning as designed and undertaking routine environmental monitoring.  Similar to the operation/restoration phase, impacts to terrestrial ecology may arise from increased human activities (ie, vegetation management) in the area resulting in disturbance to the restored habitats and the surrounding natural habitats in CWBCP and associated wildlife, if uncontrolled.  Impacts to subtidal habitats particularly the corals are not expected during the aftercare phase with the proper control of landfill leachate.  Given the generally low level of disturbance required to manage the Extension Site it is not expected that the aftercare of the Extension will cause adverse ecological impacts. 

9.9.4                                Cumulative Impact

TKO Area 137 is planned to be developed for deep waterfront industrial uses.  A C&D Material Handling Facility is currently committed to be developed in the area.  No adverse cumulative ecological impacts are expected as the TKO Area is a disturbed/developed area with negligible ecological value.

9.9.5                                Impact Evaluation

Construction Phase

Habitat Loss – Potential impacts to ecology have been evaluated according to Table 1 of Annex 8 of the EIAO-TM.  Tables 9.9a to 9.9e present an evaluation of the habitat loss due to the proposed Extension.

Table 9.9a      Overall Impact Evaluation for Plantation within the Extension Site

Evaluation Criteria

Plantation

Habitat quality

Low

Species

The potential exists for direct and indirect impacts to the wildlife, particular species of less mobility

Size/Abundance

Area loss is approximately 12.2 ha permanently

Duration

The impact will persist during the construction and operation phases.  Compensatory planting will expect to be provided during restoration and aftercare phases.

Reversibility

The plantation may take approximately 5-10 years to be re-created

Magnitude

The scale of the habitat loss is moderate in the context of the surrounding similar habitats

Overall Impact Conclusion

Low

Table 9.9b      Overall Impact Evaluation for Shrubland within the Extension Site (Excluded Areas located within the CWBCP and Outside the Existing SENT Landfill)

Evaluation Criteria

Shrubland

Habitat quality

Moderate

Species

The potential exists for direct and indirect impacts to the wildlife, particular species of less mobility

Size/Abundance

Area loss is approximately 1.4 ha

Duration

The impact will be temporary during the construction and operation phases.  Compensatory planting will expect to be provided during restoration and aftercare phases.

Reversibility

The shrubland may take approximately 10 years to be re-created

Magnitude

The scale of the habitat loss is small in the context of the surrounding similar habitats

Overall Impact Conclusion

Low to moderate

Table 9.9d      Overall Impact Evaluation for Disturbed/ Developed Area within the Extension Site (Excluded Areas located within the CWBCP and Outside the Existing SENT Landfill)

Evaluation Criteria

Disturbed/ Developed Area

Habitat quality

Nil

Species

The potential exists for direct and indirect impacts to the wildlife, particular species of less mobility and species of conservation interests including Japanese Pipistrelle

Size/Abundance

Area loss is approximately 34.2 ha permanently

Duration

The impact will persist during the construction and operation phases

Reversibility

The disturbed/ developed area is readily re-creatable  

Magnitude

The scale of the habitat loss is small in the context of the surrounding similar habitats

Overall Impact Conclusion

Negligible


Table 9.9e      Overall Impact Evaluation for Shrubland, Grassland and Developed Area within the CWBCP (Outside the Existing SENT Landfill)

Evaluation Criteria

Shrubland Encroached within the CWBCP

Grassland Encroached within the CWBCP

Disturbed/ Developed Area Encroached within the CWBCP

Habitat quality

Moderate

Low to moderate

Negligible

Species

The potential exists for direct and indirect impacts to the wildlife, particular species of less mobility and species of conservation interests including Japanese Pipistrelle, Common Buzzard, Brown Hawk Owl, White-edged Blue Baron, Indian Fritillary, Swallowtail and Common Rat Snake.

The potential exists for direct and indirect impacts to the wildlife, particular species of less mobility

The potential exists for direct and indirect impacts to the wildlife, particular species of less mobility

Size/Abundance

4.6 ha of shrubland will be lost.

Area loss is approximately 0.1 ha

Area loss is approximately 0.4 ha

Duration

The impact will be temporary during the construction and operation phases.  Compensatory planting and habitat enhancement is expected to be provided during restoration and aftercare phases.

The impact will be temporary during the construction and operation phases.  Compensatory planting and habitat enhancement is expected to be provided during restoration and aftercare phases.

The impact will be temporary during the construction and operation phases.  Compensatory planting and habitat enhancement is expected to be provided during restoration and aftercare phases.

Reversibility

The shrubland may take approximately 10 years to be re-created. 

The grassland may take approximately 5 years to be re-created 

Readily reversible

Magnitude

The scale of the habitat loss is small in the context of the surrounding similar habitats.

The scale of the habitat loss is small in the context of the surrounding similar habitats

The scale of the habitat loss is small in the context of the surrounding similar habitats

Overall Impact Conclusion

Low to moderate

Low

Low

Impacts on Wildlife:  Reduction of wildlife species abundance/diversity and ecological carrying capacity is expected to be minimal due to the loss of a relatively small area of natural habitat.  The steep slope of the affected area also limits wildlife usage.  In addition, the majority of the Extension Site is highly disturbed and is not the preferred habitat for general wildlife. 

The impacts due to the loss of foraging ground are also considered to be minimal given the presence of large area of similar habitats in the vicinity.  It should be noted that the affected area is located next to currently highly disturbed areas.

Given that there was no aquatic fauna recorded in the seasonal streams and the perimeter surface water cut-off channel will be effectively operated to avoid any discharge outside the Extension Site, impacts to aquatic life due to the change in water quality, sedimentation rate and pattern are expected to be minimal.

Impacts of species of conservation interest recorded within the Extension Site are summarised in Table 9.9f.


Table 9.9f            Overall Impact Evaluation for the Species of Conservation Interest

Species of Conservation Interest

Impacts

Impacts to Wildlife

Location Recorded

Mammals

 

 

 

Japanese Pipistrelle

A part of their associated habitat (approximately 34.6 ha of disturbed/developed area and 6 ha of shrubland) will be affected. There are extensive similar habitats in proximity.

Low

Disturbed/developed area within Extension Site and Shrubland within the encroached area in CWBCP.

Brown Noctule Bat

A part of their associated habitat (approximately 34.6 ha of disturbed/developed area) will be affected. There are extensive similar habitats in proximity.

Low

Disturbed/Development area within the Extension Site

Birds

 

 

 

Brown Hawk Owl

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP.

Greater Coucal

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP.

Common Buzzard

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP.

Black Kite

A part of their associated habitat (approximately 34.6 ha of disturbed/developed area, 12.2 ha of plantation and 6 ha of shrubland) will be affected. There are extensive similar habitats in proximity.

Low

Soaring over a variety of habitats within the Study Area.

Butterflies

 

 

 

White-edged Blue Baron

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP

Indian Fritillary

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP

Swallowtail

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP

Tooth Sunbeam

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area of CWBCP

Reptiles

 

 

 

Common Rat Snake

A small part of their associated habitat (approximately 4.6 ha of shrubland) will be affected.  There are extensive similar habitats in proximity.

Low

Shrubland within the encroached area in CWBCP

Corals

 

 

 

A total of nineteen species of hard corals recorded

Indirect impact to coral communities from potential leakage of landfill leachate expect to be minimal

Low

Subtidal habitats along the coastlines in the vicinity

In view of similar habitat in the vicinity and high mobility of the fauna species of conservation interest, it is anticipated that the construction, operation, restoration and aftercare of the Extension will not cause any adverse impacts to these species.

Habitat Fragmentation and Isolation:  Habitat fragmentation and isolation are not expected as the majority of the affected habitats are either disturbed or located next to developed areas.  It should be noted that the areas within the CWBCP are generally steep and are expected to be mainly utilized by birds and butterflies, which are less affected by such fragmentation and isolation effects.

Impacts on Habitats and Associated Wildlife within Encroached Area of CWBCP and Outside the Existing SENT Landfill:  The impacts of the loss of habitats within the encroached area of CWBCP are considered low to moderate in view of the high mobility of the species of conservation interest and general wildlife, and large extent of similar habitat in the vicinity.  The construction of the Extension Site will temporarily restrict the habitat utilisation of general wildlife within the encroached area of CWBCP; however, no unacceptable impacts are anticipated.  With the provision of enhanced habitats of higher ecological value (ie woodland) after the restoration of the impacted areas and under a proper planting scheme and management, the wildlife diversity and abundance are expected to be enhanced. 

Operation/Restoration Phase

Ecological impacts associated with the operation and restoration of the Extension due to the accidental leakage of leachate, other wastewater and landfill gas are not expected by implementation of properly designed and operated landfill gas, leachate and surface water/groundwater management systems (see Section 3).  A comprehensive environmental monitoring and audit programme will be implemented.

Other Impacts:  As no streams or water gathering areas will be affected due to the Extension, and no marine works will be required, the hydrology and hydrodynamic properties of the Study Area would not be affected.

The base of the landfill (either existing SENT Landfill or the Extension) has been designed to be kept above the groundwater level (see Section 3), the hydrogeology of the area is not expected to be influenced.

Secondary impacts to the surrounding habitats (generally with low to moderate ecological value), including the sub-tidal habitats (coral communities) in the vicinity and associated wildlife may arise from the potential for increased noise impact, blasting works, human activities and disturbance such as hill fire, import, storage or dumping of construction materials and construction site runoff.  The impacts are expected to be low owing to the current disturbed nature of the majority of the site, and given that regular site audits on good construction practice and surface water management system will be employed during the construction, and operation/restoration phases. 

Aftercare Phase

Given the generally low level of disturbance required to manage the restored Extension it is not expected that aftercare activities will cause adverse ecological impacts.

9.10                                  Mitigation Measures

Annex 16 of the EIAO-TM states that the general policy for mitigation of significant ecological impacts, in order of priority, is:

Avoidance:  Potential impacts should be avoided to the maximum extent practicable by adopting suitable alternatives;

Minimisation:  Unavoidable impacts should be minimised by taking appropriate and practicable measures such as constraints on intensity of works operations or timing of works operations; and

Compensation:  The loss of important species and habitats may be provided for elsewhere as compensation.  Enhancement and other conservation measures should always be considered whenever possible.

At each stage, residual impacts are to be re-assessed to determine whether there is a need to proceed to the next stage of mitigation.  The following measures have been developed in accordance with this approach to mitigate the impacts. 

9.10.1                            Avoidance

Five different extension options have been reviewed (refer to Section 2.3).  With reference to Annex 16, Section 3.1(a) of the EIAO-TM, areas of ecological importance (in this case the Country Park) shall be conserved as far as possible.  Options without the encroachment of CWBCP were considered first.  However, these options can only provide limited void capacity which will not be able to accommodate the waste generated in the forecast period, even with effective waste reduction and recycling measures as stated in the Policy Framework for the Management of MSW (2005-2014).  Extending the SENT Landfill with these options would not enable the Government to make adequate provision for future waste management in the catchment area and at strategic level (see Section 2.2).  Engineering measures have been considered to maximize the void space offered by these non-encroachment options.  However, it was found that massive retaining wall/earth bunds (in the order of 40m) will be required which will be visually intrusive and technically very challenging and would still not increase the void space to meet the demand.  Furthermore, the feasibility of this solution is uncertain as there is no precedent of building a sanitary landfill with such a depth of retaining structure.  TKO Area 137 is designated for deep waterfront uses and the ongoing landuse planning reveals that the demand for land within this area is high and only 15 ha can be allocated for the landfill extension.  With the 15 ha of available land in TKO Area 137 plus using the piggyback approach onto the existing SENT Landfill to maximize the available void space for the Extension, the landfill extension can only provide around 10Mm3 (around 4 years of landfill life), which does not allow sufficient time for the new generation of waste management facilities to be developed.   

It is understood that there is a public need for both adequate landfill space and Country Parks.  Landfill disposal at SENT is necessary until such time as South East Kowloon Transfer Station and Construction Waste Handling Facility are all operational (see Section 2.2).  Under an optimistic set of conditions to form a target programme at the present stage, they could all be in place by 2017, at the earliest.  With SENT expected to be full by 2012, at least six years of additional void space is necessary.  This can only be achieved by the encroachment option 3b.  It is important to extend the lifespan of the SENT Landfill based on Option 3b so that the Government can have time to plan and develop these new waste handling facilities.

The proposed encroachment area of approximately 5.1 hectares of land into the CWBCP, is primarily a coastal slope that is not easily accessible.  The habitats (grassland and shrubland) are not of high ecological value.  All of the species of conservation interest recorded within the area were found to be of high mobility and were found to have access to large extent of similar habitats close by and within the CWBCP area.  Hence, no adverse ecological impacts are expected.  When the encroached area is restored together with the fully restored landfill after the completion of landfilling operation, it is anticipated that the whole restored areas would be enriched to enable a higher amenity value for public enjoyment and higher ecological value under a proper planting scheme and management.

Hence, while encroachment cannot be avoided, an encroachment of 5.1 ha into the CWBCP is considered to be a balanced option, maximizing void capacity to meet the landfill space demand while minimizing disturbance to natural habitats.  It should be noted that the boundary of CWBCP will not be changed and access to the affected area will only be temporarily restricted.  The habitat quality will be enhanced as a result of habitat enhancement, compensatory planting and proper management which will form an integral part of the SENT Landfill Extension Project.

9.10.2                            Minimisation

The previous discussion in Section 9.9 has indicated that the potential ecological impacts due to the construction, operation, restoration and aftercare of the Extension are considered to be low to moderate.  The following measures are recommended to further reduce the potential impacts and disturbance to the surrounding habitats. 

Habitat and Wildlife

·           According to the option selection for the Extension (for details please refer to Section 2), this proposed option involves partial encroachment into areas within the CWBCP in order to maximise the total volume of the Extension.  The disturbance of the existing area within CWBCP will comprise 4.6 ha of shrubland, 0.1 ha of grassland and 0.4 ha of disturbed/developed area only. 

Measures for Controlling Construction Runoff

·           Exposed soil areas will be minimised to reduce the contamination of runoff and erosion;

·           To prevent stormwater runoff from washing across exposed soil surfaces, perimeter channels will be constructed in advance of site formation works and earthworks and intercepting channels will be provided, for example along the edge of excavation;

·           Silt removal facilities, channels and manholes will be maintained and the deposited silt and grit will be removed regularly to ensure they are functioning properly at all times;

·           Temporary covers such as tarpaulin will also be provided to minimise the generation of high suspended solids runoff;

·           The surface runoff contained any oil and grease will pass through the oil interceptors; and

·           Control measures, including implementation of excavation schedules, lining and covering of excavated stockpiles will be implemented to minimise contaminated stormwater run-off from the Extension site. 

Good Construction Practices

·           Fences along the boundary of the Extension Site will be erected before the commencement of works to prevent vehicle movements, and encroachment of personnel, onto adjacent areas;

·           The work site boundaries will be regularly checked to ensure that they are not breached and that damage does not occur to surrounding areas;

·           The quantity of explosive used and the dimensions and spacings of shotholes will be carefully designed to minimise air overpressure, flyrock generation and ground-borne vibration;

·           Use of fine blast nets, screens and other protective covers to prevent the projection of flying fragments and material resulting from blasting.  The loose material and stones in the site will be removed before blasting to minimise flying fragments affecting the surrounding areas and the blasting area will also be wetted prior to blasting to minimise dust. 

Measures for Controlling Leakage of Landfill Leachate

·            Leachate will be contained within the Extension by the proposed impermeable leachate containment system and collected by the installation of drainage system to prevent potential leakage of leachate to habitats in the vicinity.  The implementation details of managing leachate can be referenced to Section 5 - Water Quality Assessment.

Measures for Controlling Leakage of Landfill Gas

·            Disturbance to habitat in the vicinity and associated wildlife due to leakage of landfill gas will be prevented by proper management of the landfill gas generated from the Extension.  Ignition fires will be prohibited to occur within the boundary of the Extension Site.  Surface emission and off-site migration of landfill gas will be regularly monitored, which are detailed in Section 7 - Landfill Gas Hazard assessment.

9.10.3                            Compensation

As the Extension will encroach into the Country Park, adequate on-site and/or off-site mitigation measures shall be employed in accordance with the requirements of the EIAO-TM.  The following compensation planting is recommended as mitigation for the habitats affected due to the proposed Extension. 

·            Provision of 6 ha of mixed woodland planting to compensate for the loss of shrubland.  To enhance the ecological value of the encroached area within CWBCP, mixed woodland will be planted on the affected areas (approximately 6 ha, originally shrubland); and

·            Provision of a mosaic of grassland and shrubland in the remaining areas of the Extension Site.

The mixture of grassland, shrubland and woodland habitats is recommended to diversify the habitats to support various wildlife, in particular butterflies, birds and herpetofauna and blend into the existing undisturbed ecological environment.  A conceptual planting plan is presented in Section 10 – Landscape and Visual Impact Assessment section (see Figure 10.6a).  This recommendation also complies with the mitigation measures proposed in the existing SENT Landfill EIA, which suggested compensatory p