2.1 Purposes and Objectives of the Project
2.1.1.1 As discussed in Section 1.1, the Project aims to upgrade the structural and facility standards of Tung Ping Chau (TPC) Public Pier for safe pier usage by local villagers, mariculturists, visitors and tourists.
2.1.1.2 The existing TPC Public Pier has two landing steps of 1.1m wide each. The width of these landing steps is less than the standard width of 2m, and there are safety concerns for passengers boarding on / disembarkation off vessels. The solid pier at the pier head is only 14-15m long, which is not long enough for side-berthing of typical public vessels.
2.1.1.4 This Project will address these operational and safety problems and provide opportunities to bring benefits in enhancing TPC Pier with upgraded facilities such as barrier-free facilities, canopy, seats, etc.
2.2.1 Description of the Existing Pier
2.2.1.1 TPC Public Pier was originally constructed in the 1960s and upgraded in 2008 to address certain structural problems. The pier is located within the Tung Ping Chau Marine Park, which is well known for the protection of coral communities, algal bed and unique geological features. The existing TPC Public Pier is around 98m long, comprising an about 14m long solid pier head, about 35m long catwalk and an about 49m long rubble causeway. The solid pier head is about 5.5m wide, and consists of a 1.1m wide flight of steps on each side of the pier head. The pier head level is about 4.9m above the Principal Datum (PD), and the pier head is covered by a pitched roof structure. A general view of the pier is shown in Image 2.1.
Image 2.1 Layout of Existing TPC Public Pier
2.2.1.2 A hydrographic survey was undertaken in Oct 2018 and the seabed level at the existing pier head was about -3mPD.
2.2.2 Safety Concerns
2.2.2.1 Due to poor structural conditions of the walkway at Tung Ping Chau Public Pier in 2004, improvement works had been proposed to replace it by a new walkway spanned between new piles and the existing pier head. The improvement works also comprised widening of the causeway and catwalk. The pier head was covered by a new canopy, and the structure of the pier head remained as it had been (see Image 2.2 and Image 2.3).
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Image 2.2 Pier was built in
1960s |
Image 2.3 Improvement Works
in 2007 |
2.2.2.2 There are two landing steps at the existing pier head, but the landing steps are narrow and steep. They have posed serious safety concerns for passengers boarding on / disembarkation off vessels to the pier; they are sub-standard according to the current code of practice (Image 2.4). Some near-miss accidents at the landing steps were reported by the locals and villagers. There is serious accessibility issue for those who are in need, including aged people, when using this pier.
2.2.2.3 Besides, the existing pier head is only 14.5m long and it is too short that it is not possible to berth the full length of typical passenger vessels alongside the pier. Vessels can only berth undesirably at the boat bow (Image 2.5). In view of these people and vessel navigation/berthing safety issues, it is crucial to carry out improvement works at this pier to ensure safe uses of this pier.
2.2.2.4 These concerns are listed as follows and are elaborated in the following paragraphs.
(1) Narrow and steep flights of landing steps; and
(2) Undesirable berthing arrangement.
Narrow and Steep Flights of Unsafe Landing Steps
Undesirable Berthing Arrangement
2.2.2.6 The pier head is about 14m-15m long. Due to the short length of the pier head, the pier head is not adequate lengthwise for allowing complete side berthing of the full length of Kaito ferry vessels which are typically 25m to 30m. Vessels can only berth undesirably at the boat bow. In view of vessel navigation/berthing safety issues, it is crucial to carry out improvement works at the pier to provide a sufficient length for vessels to complete side berthing.
Image 2.4 Existing Narrow and Steep Landing Steps of Tung Ping
Chau Public Pier
Image 2.5 Undesirable
berthing at the Boat Bow of Existing Tung Ping
Chau Public Pier
2.2.3 Villagers’ / Pier Users’ Concerns
2.2.3.1 There have been repeated requests from Village Representatives (VRs) of the five villages on TPC, SKNRC members and TPDC members over the years to improve the safety condition when using the pier. During the consultation meetings held with elected-by-villagers VRs, SKNRC members and TPDC councillor in May 2019 for this Project, they reported that there had been accidents or near-misses happened in the past due to the narrow and steep landing steps. They expressed support to this Project and urged the earlier implementation of this improvement works.
2.2.4 Barrier-Free Facilities
2.2.4.1 It has been the Government's established policy to provide barrier-free facilities for people in need with a view to enabling them to freely access premises and make use of community facilities and services on an equal basis with others. Accessible facilities would provide opportunities for these people to live independently, participate in various social activities and integrate into the community. To improve accessibility of public pier, the accessibility (1) between the vessel and the pier, and (2) within the pier shall be improved.
2.2.4.2 The sea level is changing due to tides and other meteorological effects creating a varying level difference between the deck of vessels and the pier. To enhance the accessibility between the deck of vessels and the pier, their level difference should be maintained at a fixed height to enable embarking/disembarking via a movable plank (gangplank). This can be achieved by berthing against a floating platform, which rises and falls with the vessels during sea level changes.
2.2.4.3
Accessibility within the pier would provide
accessibility for passengers from the floating platform to TPC and vice versa.
As the existing pier is currently not manned, installation of lift or hoist to
assist passengers to and from the floating platform from the existing pier is
not possible, therefore a series of fixed and movable ramps is proposed. The
ramps are fixed in position except the section connecting the floating platform
which could be moved according to sea level changes.
2.2.5 Sustainable Development of the Geopark
2.2.5.1 As mentioned in Section 1.2.1.1, Tung Ping Chau Public Pier is located within Hong Kong UNESCO Global Geopark (Geopark). The Hong Kong UNESCO Global Geopark is currently a member of the Global Geoparks Network (GGN), of which one of the key features is to promote earth science and sustainable development through geo-tourism and education. According to the protection level of Geopark, Tung Ping Chau belongs to “Integrated Protection Area”, because it carries function for geo-tourism because its carrying capacity is relatively higher than that in other areas of Geopark. With the implementation of the proposed pier improvement works, Tung Ping Chau Public Pier would provide safer access for the public to visit Tung Ping Chau, so as to improve the experience of the public visiting the geopark and thus supporting the sustainable development of the geopark.
2.2.6 Enhancement of Recreation and Education Potential of Country Parks
2.2.6.1 Tung Ping Chau, being the easternmost outlying island in Hong Kong, is part of the Plover Cove (Extension) Country Park and Tung Ping Chau Public Pier is the only access point on the island. According to the Consultancy Study on Enhancement of the Recreation and Education Potential of Country Parks and Special Areas by AFCD, the general public in Hong Kong hopes for enhancement of existing facilities in Country Parks especially on the accessibility of Country Parks as well as facilitating visits by people-in-need. After implementing the proposed pier improvement works, it would provide upgraded facilities and barrier-free access in responding to the public aspiration.
2.3 “With” and “Without” the Project
Without Project Scenario
2.3.1.1 Without the Project, the current users including villagers and visitors still have to rely on the existing TPC Public Pier for waterborne transport to access TPC. As TPC is not accessible via any vehicular road, the existing TPC Public Pier is the only transport infrastructure in TPC. The safety issues such as narrow and steep flights of landing steps and insufficient berth length for side berthing of vessels continue to exist, posing threats to pier users, especially to those with special needs. Enhancing accessibility using barrier-free facilities would not be possible if the Project was not implemented. From the environmental perspectives, the amenity and visual aesthetic of the pier cannot be enhanced without the Project.
2.3.1.2 There is currently one licenced kaito service between Ma Liu Shui and Tung Ping Chau. The service only operates on Saturday, Sunday and public holidays, the current operator is Tsui Wah Ferry Service (HK) Limited. The ferry schedule is 9:00am (and 3:30pm only on Saturday) from Ma Liu Shui to TPC and 5:15pm departed at TPC. The largest vessel of the Kaito service is around 29m long and 7m wide with 1.8m draft for berthing. Other than licenced kaito service, government vessels including AFCD and FEHD would also use the pier for their operation in weekdays and weekend.
With Project Scenario
2.3.1.3 With the Project, the TPC Public Pier will be upgraded to be integrated with a new pier structure that can allow construction of wider and shallow gradient landing steps providing safer means of access for the patrons and pier users. Other enhancement facilities such barrier-free facilities, canopy, seats, etc. could enhance the convenience, pleasures and satisfaction of pier users.
2.3.1.5 As there would be no planned increment in the frequency of licenced kaito services after the pier improvement work, no operational impact is anticipated.
2.3.1.6 The implementation of the Project would not cause adverse environmental impacts during the construction phase if mitigation measures and good site management practices are properly adopted. These potential impacts include the water quality, marine ecology and fisheries impacts from the marine-based construction works, air quality impact from fugitive dust emission, noise impact from the use of powered mechanical equipment and waste and environmental hygiene implications within the Tung Ping Chau Marine Park. Environmental impacts are therefore duly assessed throughout the EIA stage. A series of mitigation measures and good site management practices are recommended to avoid, minimise and mitigate the potential adverse environmental impacts where practicable (see Section 12 and Section 13 for details). A comprehensive and effective environmental monitoring and audit programme is also proposed to ensure the mitigation measures and good site practices are properly implemented.
2.4 Environmental Benefits of the Project
2.4.1 Increase Surface Area for Corals
2.4.1.1 As discussed in Section 2.2, the Project will extend the TPC Public Pier towards the sea to allow safety side berthing for vessels and the new pier structures comprise underwater hard structural elements. There will be an increase of the surface area of hard substratum, which will incorporate ecological enhancement design and could promote the colonization of epibenthos such as coral colonies. According to the current design (see Section 2.6), there would be about 33 nos. of piles with an average diameter of about 0.8m to 1m. This would provide an additional area of around 250m2 below the Mean Lower Low Sea Level (i.e. +0.5mPD) and hence would provide an additional surface area for corals. The above-seabed downstand wall will also provide at least 160m2 of hard substrate surface area. Nevertheless, the total number and the actual diameter of the piles and size of the downstand wall would be subject to the detailed design. By suitable design such as uneven surface and/or selected patterns, the colonization of epibenthos would be faster and/or more abundant, and the ecological functions of the subtidal portions of these structures could be further enhanced.
2.4.2 Enhance Visual Amenity of the Pier
2.4.2.1 By the implementation of the pier improvement works with modern design and more compatible colour scheme and texture, the visual appearance of the TPC Public Pier can be better enhanced. Hence, the status of TPC, as a popular destination for eco-tourism, can be uplifted.
2.4.3 Reduce Air Quality and Noise Impacts during Operational Phase
2.4.3.1 As discussed in Section 2.2, the length of the improved pier will increase from 98m to approximately 124m with the landing steps shifted seawards. The proposed berthing locations associated with the marine traffic emissions and marine traffic noise will be further away from the coast and the sensitive receivers as compared with the current condition without pier improvement. Hence, the sensitive receivers may result in a slight improvement of air quality and noise impacts. Details will be discussed further in Section 3.5 and Section 4.5.
2.5
Tackling Environmental Challenges and
Options Considered
2.5.1.1
Due consideration has been given
in formulating the pier design to overcome environmental challenges faced by
the Project. The hierarchy of “Avoid,
Minimise and Mitigate” has been adopted during the process to protect the
environment as much as practicable. The key principles adopted
to tackle all the environmental challenges are discussed below.
2.5.2
Environmental
Challenges Posed by Ecological Resources
·
Corals in the vicinity of the pier;
·
Tung Ping Chau Marine Park;
·
Ping Chau Site of Special Scientific Interest (SSSI); and
·
Plover Cove (Extension) Country Park.
2.5.3
Avoidance of Open
Sea Dredging Works
2.5.3.2
In order to avoid any adverse
water quality impacts and hence ecological impacts associated with the Project
which are also within the Tung Ping Chau Marine Park, the layout has been very
mindful on the configuration and design of the pier. According to the latest
design layout, open sea dredging works would be totally avoided during the
construction phase. By avoiding open sea dredging works, any adverse water
quality impacts and hence impacts on marine ecological resources during the
construction phase would be minimised as much as practicable.
2.5.4
Avoidance of Wastewater
/ Effluent Discharge During both Construction and Operational Phases
2.5.4.1
Given that the Project is within
the Tung Ping Chau Marine Park which is a Water Sensitive Receiver (see Section 5.3), it is important to
implement all practicable measures to avoid any discharge of wastewater /
effluent discharge into Tung Ping Chau Marine Park during both the construction
and operational phases.
2.5.4.2 During the construction phase, the potential impacts that would be generated by the construction team has been assessed in detail (see Section 5.4.2). The Contractor will be prohibited to discharge any wastewater and effluent into the Tung Ping Chau Marine Park. Any wastewater and effluent that would be generated during the construction activities would be transported away for proper treatment and disposal.
2.5.4.3 During the operational phase, the Project has been designed to avoid any need for using detergents/chemicals during routine maintenance (see Section 5.5). This would therefore avoid any potential water quality impacts on the Tung Ping Chau Marine Park.
2.5.5
Avoidance
of Works in Country Park and Site of Special Scientific Interest
2.5.5.1 As discussed in Section 1.2, Plover Cove (Extension) Country Park is located at approximately 70m from the existing pier. The habitat between the Plover Cove (Extension) Country Park and the existing pier is the footpath and the intertidal shore which have ecological values of Low to Moderate. The works will not encroach upon the Plover Cove (Extension) Country Park as illustrated in Figure 1.1. Direct impacts on the natural resources in Plover Cove (Extension) Country Park can be avoided.
2.5.5.2 In addition, Ping Chau is also famous for its distinctive, attractive and unique geological features, physical landforms and has been designated as the Ping Chau Site of Special Scientific Interest (SSSI). The Project also avoids any works to be undertaken within the Ping Chau SSSI to protect the special geological features of the island.
2.5.6
Avoidance of Solid
Pier Design
2.5.6.1 The Project is located at the eastern coast area of TPC facing towards Ping Chau Hoi. In the Ping Chau Hoi area, the deepest seabed level is approximately -9mPD which has a water depth of about 9.5m at the mean lower low water (MLLW).
2.5.6.2 The existing pier comprises a solid pier head, a catwalk supported by piles and a rubble causeway. In order to minimise any additional impacts caused by the proposed pier improvement works, the structure of the proposed pier would adopt concrete decks on top supported by piled foundation. The diameter of the foundation would be approximately 0.8m to 1m and the pile spacing is approximately 5m to 8m. Such a configuration is typical for other similar piers improvement works in Hong Kong, for instance, the Reconstruction of the Sharp Island Pier.
2.5.6.3 Due to small footprint of the new supportive piles, changes in the flow regime and hydrodynamic in Ping Chau Hoi are limited. The proposed pier improvement works have minimised any impacts on hydrodynamics as much as practicable. Details are provided in Section 5.5.
2.5.7
Minimisation of
Impacts on Corals
2.5.7.1 The ecological baseline survey as detailed in Section 8.4 has confirmed the abundance of corals within and in the vicinity of the Project. The ecological value of the coral communities has been ranked as High. In order to minimise the impacts on coral, the design of the Project has adopted the option with lower impacts to corals colonies by minimizing the number of coral colonies within the footprint, reducing around 1/3 affected colonies. By adopting concrete decks on top supported by piled foundation, this would largely reduce the seabed disturbance and hence the direct and indirect impacts on corals.
2.5.8
Minimisation of
Waste Generation During Construction Phase
2.5.8.1 The pier improvement works for TPC Public Pier endeavour to minimise the waste generation in relation to integrate the structures of the existing pier to the new pier structures. It therefore minimises the generation of over 600 m3 construction and demolition (C&D) materials disposed of to the landfills/public fill banks if the whole pier head was demolished and reconstructed.
2.5.8.2 The Project will not involve any works on land and avoids tree felling during the construction of pier. Hence, it minimises vessel trips required for the delivery of C&D materials and waste from the remoted Project site to the disposal sites. As such, disturbance from the marine vessels to the marine park can be minimised.
2.5.8.3 In order to minimise the waste generation at the Project site during construction phase, the most effective approach is to adopt pre-cast elements as much as practicable. By adopting this approach, most of the elements for the deck would be pre-cast off-site and then transported to the site for final assembly.
2.5.9 Minimisation of Construction Vessels During Construction Phase
2.5.9.1 As open sea marine dredging would be avoided and pre-cast elements would be adopted as much as practicable, the number of construction vessels during the construction phase would also be minimised. Since the Project is located within the Tung Ping Chau Marine Park, it is inevitable that the construction vessels will travel within the marine park. Hence, by minimising the number of construction vessels required, any indirect impacts caused by those vessels on the marine park would also be minimised as well. Nevertheless, appropriate good practices would be adopted by the Contractor to operate the construction vessels.
2.5.10.1 Due considerations have been given in formulating the pier design to address environmental challenges in this Project. The hierarchy of “Avoid, Minimise and Mitigate” has been fully adopted in the process to protect the environment as much as practicable. Hence, the design has given due consideration on the locations and forms of the pier improvement works to minimise the environmental impacts.
1. Options Considered for Pier Locations
2.5.10.2
Given the widespread spatial
distribution of the coral communities in Tung Ping Chau Marine Park, it is
likely not practicable to avoid all the coral colonies. Hence, the design has
given due consideration on the locations of the pier improvement works to
minimize the impacts on the coral communities as much as practicable. The
options that have been duly considered include the following (see Image 2.6):
·
Option 1: Extension of the existing TPC Public Pier to provide a new structure
for construction of landing steps and incorporation of floating pontoon;
·
Option 2: A new pier to the south of the existing TPC Public Pier; and
·
Option 3: A new pier to the north of the existing TPC Public Pier.
Image 2.6 Location Options of
Proposed TPC Pier Improvement
2.5.10.3 For Option 1, the pier improvement work focuses on the extension/ modification of the existing pier. The area is around 42m long and 15m wide. The construction works mainly involve marine works in a sufficient water depth. No land works is anticipated in this option but a temporary pier is needed during construction stage. The temporary pier is likely to be located within the works area. Piles are required to support both the new pier and the temporary pier, and these pile foundations will likely be bored piles. Casings will be installed to separate the pile arisings from the water body to minimise any risk of water pollution. After the provision of a new berth, the piles for the temporary pier will then be removed by wire saw cutting, blade saw cutting or similar method as close to the seabed as practicable.
2.5.10.4 For Option 2, a completely new pier will be constructed from shore to sea and the pier head will be extended to the area with sufficient water depth. It is anticipated that the new pier will be around 110m long and 6m to 15m wide. Construction works include both land and marine works which are more difficult than those of Option 1. Construction of temporary pier is not required and hence the existing pier would still in use during construction of the new pier, and would be demolished and removed afterwards. Solid wastes including inert and non-inert C&D materials are expected to be generated from the demolition work for the existing pier.
Environmental Considerations
2.5.10.6 The inshore water of TPC is a well-known habitat of coral communities with high coral coverage. According to the past EIA project profile – “Improvement works to Tung Ping Chau Public Pier” (PP-222/2004), a quantitative coral mapping was conducted (Image 2.7). It was observed that coral distribution is relatively low at the area near the existing pier head whilst the area closer to the shore was relatively high.
2.5.10.7
For Option 2 and Option 3, the
new piers and corresponding works area would encroach an area zoned as “Coastal
Protection Area” (“CPA”) on the Draft Ping Chau Outline Zoning Plan No.
S/NE-PC/1 which is to conserve, protect and retain the natural coastlines and the
sensitive coastal natural environment, including distinctive, attractive and
unique geological features, physical landforms etc. These options will also
encroach upon Ping Chau Site of Special Scientific Interest (SSSI). Both
options would impose more negative impacts on the distinct geographical features of the
coastlines and the sensitive coral communities at the near-coast area.
Terrestrial ecology might also be affected due to the near shore construction
works of pier improvement for Option 2 and Option 3.
2.5.10.8 Furthermore, Option 3 is encroached upon the Tung Ping Chau Marine Park Core Area which is envisaged that it poses the most negative impacts on coral among 3 options.
2.5.10.9 For Option 1, it is envisaged that the coral distribution at the location of new pier is relatively low as the pier improvement work would be carried out surrounding the existing pier. No encroachment of “CPA” and Ping Chau SSSI is anticipated under this option as only marine works would be carried out.
2.5.10.10 In addition, the demolition of the existing pier for Option 2 and Option 3 would inevitably involve larger scale of marine works which would generate more C&D materials to be delivered for off-site disposal as well as potential water quality impacts.
Image 2.7 Distribution
of Coral Colonies around Tung Ping Chau Public Pier (EIA PP-222/2004)
(Source: https://www.epd.gov.hk/eia/english/alpha/aspd_430.html)
2.5.10.11 Taking the potential environmental impacts into consideration, Option 1 has been selected as the preferred option. Though this Option will require the construction of a temporary pier, it totally avoids any land-based work within the “CPA” and SSSI which are zoned to conserve, protect and retain the natural coastlines and sensitive natural environment as well as the attractive geological features. It also avoids the demolition of the existing pier, and therefore minimise the generation of C&D materials. Option 1 will also avoid encroaching upon the relatively high coral distribution near the shore and the core area of Tung Ping Chau Marine Park.
2. Options Considered for Pier Arrangement
2.5.10.12 The pier arrangement of T-shape, L-shape and linear extension have been preliminarily considered. By considering provision of barrier-free facilities and appropriate size to allow side berthing of the Kaito ferries and other typical vessels, the tentative layout of a T-shape, L-shape and linear extension pier arrangement were preliminarily studied and shown in Image 2.8, Image 2.9 and Image 2.10 respectively.
(m) Existing TPC Public Pier
Image 2.8 Preliminary Layout of T-shape Pier Arrangement
(m) Existing TPC Public Pier
Image 2.9 Preliminary Layout of L-shape Pier Arrangement
(m) Existing TPC Public Pier
Image 2.10 Preliminary Layout of Linear Extension Pier Arrangement
Engineering Consideration
2.5.10.13 The dominant wind directions are easterly to southeasterly at Tung Ping Chau. A L-shape or T-shape pier has been considered but not preferred as vessels berthing at the pier head could be subject to boardside wave, i.e. waves directing on the sides of vessels inducing repeated bouncing of vessels against the pier, which might deteriorate the pier structure in long term. An extensively long downstand walls might be needed for those options to alleviate strong wave situation. The tentative footprints of the T-shape, L-shape and linear extension of pier arrangement are around 910m2, 780m2 and 750m2 respectively. Both T-shape and L-shape pier arrangement would result in a footprint larger than that of the linear extension one, more piled foundation and longer downstand walls would be anticipated.
Environmental Consideration
2.5.10.14 The T-shape and L-shape pier arrangement would result in a larger footprint, more piled foundation, longer downstand walls and hence more seabed and water column losses are anticipated when compared with the linear extension arrangement.
Preferred Pier Arrangement
2.5.10.15 Taking the potential engineering and environmental impacts into consideration, linear extension arrangement would be selected as the preferred arrangement.
3. Options
Considered for Size of Pier
2.5.10.16 For the linear extension arrangement, the size of the proposed pier has been carefully studied with consideration of the following factors. An initial preliminary layout (Option A) was established and is shown in Image 2.11.
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Image 2.11 Initial
Preliminary Pier Layout (Option A)
Appropriate Size of Improvement Work
2.5.10.17 The existing pier is only around 5.5m wide and 14.0m long at the pier head which cannot allow complete side berthing of the full length of Kaito ferry vessels which are typically 20m to 25m long. Therefore, the proposed pier head shall at least cater for side berthing of the Kaito ferries and other typical vessels, 30m long pier head is sufficient for more safety side berthing arrangement.
2.5.10.18 Furthermore, there is only a relatively narrow covered waiting area (around 40m2) for pier users. The proposed improvement work shall consider providing sufficient waiting area (ideally with cover) to allow pier users to wait and queue for the Kaito ferry service especially during the peak hours. A larger covered waiting area shall be provided and tally with most of the existing public piers in Hong Kong (e.g. Sai Kung Public Pier).
Barrier-free Facilities Provision
2.5.10.19 Other than the proposed pier deck structure, barrier-free facilities have also been considered in the pier improvement work. Given the difference in level between existing pier level and various sea levels for operation of the floating pontoon, the proposed length of ramp and pontoon structures is about 63m.
2.5.10.20 Compared to a traditional pier head, the floating pontoon might be subject to relatively high maintenance frequency. During the time of maintenance works, the traditional pier head can provide normal service for daily operation of the pier. Therefore, both traditional pile head and floating pontoon with ramps will be provided at the proposed pier. The initial preliminary pier layout was incorporated the idea of barrier-free facilities provision.
Preliminary Ecological Review
2.5.10.21 As the Project site in TPC is located close to coral communities with relatively higher coverage, a detailed coral survey was conducted. In order to avoid and minimize coral colonies being affected by the proposed pier as far as possible, the initial preliminary pier layout against coral distribution was conducted and shown in Image 2.12.
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Image 2.12 Coral
Distribution within Initial Preliminary Pier Layout (Option A)
2.5.10.22 According to the coral distribution, there are 148 coral colonies recorded within the initial preliminary pier layout. 66 of them are considered to be readily movable. Although it is not possible to completely avoid all the coral colonies given their distribution, the proposed pier layout was thoroughly reviewed in order to further reduce the coral colonies to be affected as much as practicable.
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Image 2.13 Revised
Preliminary Pier Layout (Option B)
2.5.10.25 The revised preliminary pier layout has therefore achieved an optimum option in view of different considerations.
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Image 2.14 Coral
Distribution within Revised Preliminary Pier Layout
2.5.10.26 Translocation will be carried out for the coral colonies under the proposed Revised Preliminary Pier Layout. Coral translocation was conducted for the previous Improvement Works to Tung Ping Chau Public Pier conducted in Year 2006. At that time, a total of 41 coral colonies was translocated from the works area of the pile locations as a mitigation measure, with 15 colonies selected for monitoring. The monitoring results showed that the survival rate of the translocated colonies was 100%.
2.5.10.27 The experience of coral translocation for the Improvement Works to Tung Ping Chau Public Pier conducted in Year 2006 demonstrated the successfulness of the latest coral relocation and substratum transplantation techniques. The experience delineates the methodology of conducting survey, translocation and monitoring of coral in Tung Ping Chau Marine Park and coral translocation is therefore considered as a mitigation measures for this Project.
Summary of Options Considered
2.5.10.28 A summary of the above options is given in Table 2.1 with the preferred option identified for ease of reference.
Table 2.1 Summary
of Options Considered
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Options |
Pros |
Cons |
Preferred
Option (Y/N) |
|
1. Pier Locations |
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Option
1 |
Engineering
Considerations |
Y |
|
|
· No
demolition works will be required for the existing pier. · Only
marine-based construction work will be carried out. The complication of the
Project is lower than those of other options. |
· Additional
temporary pier will be required during construction phase. |
||
|
Environmental
Considerations |
|||
|
· The
works area of the Project will be located outside the core area of Tung Ping
Chau Marine Park, where coral coverage is high. No need to have construction
works close to the shoreline. Thus, the impacts on coral communities will be
lower than Option 2 (close to one of the Reef Check Sites) and Option 3
(where the works area is located within the core area of the Marine Park and
one of the Reef Check sites). · No
heavy demolition works will be carried out on existing pier, hence largely
reduce quantities of waste generated. Without the demolition works, the water
quality impact on the water sensitive receivers such as coral colonies are
anticipated to be the least. · Though
temporary pier will be required to be constructed and demolished during the
Project, the temporary pier supported by piles could be more readily removed
by wire saw cutting, which bears fewer environmental impacts than the
demolition of the existing pier. · Direct
encroachment on “CPA” and SSSI, where distinct geological features are
located, will not be required. |
N/A |
||
|
Option
2 |
Engineering Considerations |
N |
|
|
· No
additional temporary pier will be required. |
· Both
marine and land-based construction works are anticipated . |
||
|
Environmental Considerations |
|||
|
N/A |
· The
works area of the Project will be located near one of the Reef Check Sites where
coral coverage is high. The works area will be larger and will cover inshore
waters close to the shoreline. · Demolition
of existing pier shall be carried out for safety reason. Hence, it will
generate larger quantity of waste and potential water quality impact. · Though
construction and demolition of temporary pier will not be required to during
the Project, demolition of existing pier will be required due to safety
reason. The demolition of existing pier will involve more extensive
marine-based works, which cause more significant water quality and ecological
impacts than the demolition of temporary pier. · The
works area will directly encroach on “CPA” and SSSI, which may cause adverse
impact to “CPA” and SSSI. |
||
|
Option
3 |
Engineering Considerations |
N |
|
|
· No
additional temporary pier will be required. |
· Both
marine and land-based construction works are anticipated |
||
|
Environmental Considerations |
|||
|
|
· The
works area of the Project will be located inside the Core Area of Tung Ping
Chau Marine Park and also one of the Reef Check Sites, where coral coverage
is high. Thus, the impacts on coral communities will be higher than Option 1
and Option 2 and shall be avoided. · Demolition
of existing pier shall be carried out for safety reason. Hence, it will
generate larger quantity of waste and potential water quality impact. · Though
construction and demolition of temporary pier will not be required to during
the Project, demolition of existing pier will be required due to safety
reason. The demolition of existing pier will involve more extensive
marine-based works, which cause more significant water quality and ecological
impacts than the demolition of temporary pier. · The
works area will directly encroach on “CPA” and SSSI, which may cause adverse
impact to “CPA” and SSSI. |
||
|
2.
Pier Arrangements |
|||
|
T-Shape |
Engineering Considerations |
N |
|
|
N/A |
· Vessels
berthing at the pier head could be subject to boardside wave which might
deteriorate the pier structure in long term. · More
piled foundation and longer downstand wall are anticipated when compared with
the linear extension arrangement. |
||
|
Environmental Considerations |
|||
|
N/A |
· More
permanent marine habitat loss (both seabed and water column) is anticipated
when compared with the linear extension arrangement given that the larger
extent and longer downstand wall provision. |
||
|
L-Shape |
Engineering Considerations |
N |
|
|
N/A |
· Vessels
berthing at the pier head could be subject to boardside wave which might
deteriorate the pier structure in long term. · More
piled foundation and longer downstand wall are anticipated when compared with
the linear extension option. |
||
|
Environmental Considerations |
|||
|
N/A |
· More
permanent marine habitat loss (both seabed and water column) is anticipated
when compared with the linear extension arrangement given that the larger
extent and longer downstand wall provision. |
||
|
Linear |
Engineering Considerations |
Y |
|
|
· As
wave direction will be in parallel to vessel berthing, less bouncing of
vessel against the pier is anticipated. Hence, it enhances the safety
boarding pier users. · The
smallest footprint area is envisaged amongst three pier arrangements. The
least piled foundation and shortest downstand wall are anticipated. |
N/A |
||
|
Environmental Considerations |
|||
|
· The
least permanent marine habitat loss (both seabed and water column) is
anticipated given that the smallest extent and shortest downstand wall
provision. |
N/A |
||
|
3. Pier Sizes |
|||
|
Option
A |
· More
space will be provided on pier for pier users to wait or queue for Kaito
service. · No
demolition/modification work for the existing pier, hence lesser potential
water quality impact. |
· More
coral colonies would be affected by the proposed footprint. More ecological
impact is envisaged. |
N |
|
Option
B |
· Fewer
coral colonies would be affected by the proposed footprint. Less ecological
impact is envisaged. · Limited
demolition/modification work for the existing pier is anticipated. |
· Less
space will be provided on pier for pier users. |
Y |
2.5.11 Consideration of Construction Methodology
2.5.11.1
Various
construction methodologies have been considered in view of avoidance and
minimisation of potential environmental impacts.
Solid Pier
Construction vs. Pile-Supported Pier Construction
2.5.11.3
To
avoid the potential water quality impact, the foundations of the proposed TPC
Public Pier and the temporary pier will be composed of in-situ bored piles or similar pile types (e.g. rock socketed Steel
H-pile). As the marine piles will be constructed
with a pile casing system (see Section 2.6.3), suspended solids and drilling
fluid will be confined in the pile casing, and isolated from the external water
bodies. The proposed construction method has totally
avoided the need of open sea dredging. The pile-supported pier allows water
flow underneath the pier structures. It has much smaller hydrodynamic impact
during operation phase.
On-site
Construction vs. Prefabrication Construction
2.5.11.4 Prefabrication construction method has been proposed for the construction of deck structures of the pier. Selected concrete superstructures will be formed by pre-cast concrete offsite in a controlled environment and installed onsite when ready. This can avoid on-site casting activities that may affect water quality by minimising the storage of casting materials. Moreover, this approach can minimise the extent and duration of on-site construction activities. The time of on-site construction activities could be reduced by 10% when compared with typical in-situ construction method. The prefabrication method also minimises the waste generation on-site during the construction phase. As a result, the air quality, noise, water quality impacts and waste implications associated with these construction activities including emissions, site run-off, accidental spillage of chemicals and sewage from workforce could thus be avoided or minimised in comparison with on-site casting method.
Conventional Demolition vs. Wire Saw Demolition
2.5.11.5 The temporary pier will be decommissioned after the completion of pier improvement works. Piled foundation of temporary pier will be cut by wire saw or similar method as close to the seabed as possible. The wire saw is a saw that uses a metal wire or similar material for cutting structure from its parent structure in a safe and efficient way with limited vibration.
2.5.11.6 Compared to the conventional demolition work in mechanical mean (e.g. using chisel and grab) to remove the piled foundation, wire saw cutting would cause less vibration, limited suspended solid and hence cause less adverse impacts to the environment.
Summary of Construction Methodology Considered
2.5.11.7 A summary of benefits and disbenefits of construction methodology considered is given in Table 2.2.
Table 2.2 Summary of Construction Methodology
Considered
|
Options |
Pros |
Cons |
Preferred Option (Y/N) |
|
Solid
Pier Construction vs. Pile-Supported Pier Construction |
|||
|
Solid Pier Construction |
N/A |
·
Soft
materials on the seabed will need to be dredged. There will be great impacts
on the water quality, hydrodynamic and marine ecology issues in both
construction and operation phases |
N |
|
Pile-Supported Pier Construction |
· This
construction method totally avoids the need of open sea dredging and thus
safeguard water quality impact during construction phase. |
N/A |
Y |
|
On-site
Construction vs. Prefabrication Construction |
|||
|
On-site Construction |
N/A |
· Require
storage of more construction materials and generate more construction waste on-site · There
will be more construction activities and more PME items on-site. Hence, the
construction activities and use of PME may incur more air quality, noise and
water quality impacts |
N |
|
Prefabrication Method |
· Minimise
on-site construction activities and the use of PME on-site, which may incur
air quality, noise and water quality impacts · Minimise
storage of construction materials on-site and generation of waste on-site |
N/A |
Y |
|
Conventional
Demolition vs. Wire Saw Demolition |
|||
|
Demolition work in mechanical mean |
N/A |
· More
vibration and suspended solid are anticipated if adopting demolition work in
mechanical mean. Hence, cause more impact to the environment. |
N |
|
Wire-saw cutting |
· Less
vibration, limited suspended solids and hence cause less impacts to the
environment. |
N/A |
Y |
2.5.12 Consideration of Construction Sequence
2.5.12.1
As
the Project is located within the Tung Ping Chau Marine Park, the construction
sequence has also been duly arranged during the EIA study.
Overlapping vs. Non-overlapping of Construction Stages
2.5.12.2
Construction
will be conducted phase to phase to avoid environmental impacts. The
construction of the proposed pier will only be commenced after the completion
of the temporary pier. Likewise, the demolition of temporary pier would only be
commenced when the proposed TPC Public Pier has completed.
Successive vs.
Concurrent Construction/Demolition of Structures
2.5.12.3
Construction
of pier structures and demolition of temporary pier structures will be
conducted successively. During the construction of marine bored piles, there
will only be one to two piles constructed concurrently within the Project site.
During demolition of the piles for the temporary pier, marine piles will be cut
one by one to minimise the impact. This avoids large quantities of PME
operating concurrently within the Project site, and therefore reduces the
potential noise and air quality impacts.
Summary of Construction Sequence Considered
2.5.12.4 A summary of benefits and disbenefits of construction methodology considered is given in Table 2.3.
Table 2.3 Summary of Construction Sequence
Considered
|
Options |
Pros |
Cons |
Preferred Option (Y/N) |
|
Overlapping
vs. Non-overlapping of Construction Stages |
|||
|
Non-overlapping of different
construction stages |
·
Less
amount of construction activities occurred and less PME used in the Project
site concurrently ·
Reduce
the magnitude of negative environmental impacts |
·
Longer
duration of construction |
Y |
|
Overlapping of different
construction stages |
· Shorter
duration of construction |
·
More
amount of construction activities occurred and more PME used in the Project
site concurrently · Potentially
more environmental impacts |
N |
|
Concurrent
vs. Successive Construction/Demolition of Structures |
|||
|
Concurrent construction /demolition
of structures |
·
Less
amount of construction/ demolition activities occurred and less PME used in
the Project site concurrently · Reduce the magnitude of negative environmental
impacts |
· Longer duration of construction/demolition |
Y |
|
Successive construction
/demolition of structures |
· Shorter
duration of construction/demolition |
·
More
amount of construction/ demolition activities occurred and more PME used in
the Project site concurrently · Potentially
more environmental impacts |
N |
2.6 Proposed Development Scheme
2.6.1 Proposed Layout
2.6.1.1
The existing TPC Public Pier extends from the land towards the sea in
the northeast direction. The proposed TPC Public Pier will integrate and extend
from the existing pier head and will align in the same direction as the
existing pier. The location of the proposed TPC Public Pier is shown in Image 2.15.
|
|
Image 2.15 Location of Proposed TPC Public Pier and Proposed Temporary Pier
Proposed Temporary Pier
2.6.1.3 As the TPC Public Pier is the only transport infrastructure taking users to TPC villages, the pier operation cannot be suspended during the construction of the new pier.
2.6.1.4 For safety reasons, concurrent undertaking of upgrading works and berthing of public vessels at the existing pier cannot be allowed. Therefore, a temporary pier is required to serve the Kaito service and other public vessels and to allow upgrading of the existing pier.
2.6.1.5
During construction of the proposed TPC Public Pier, concurrent
undertaking of improvement works at the existing pier and berthing of vessels
is not spatially feasible, and it would not be safe. A temporary pier will be
extended from the head of the existing TPC Public Pier to maintain operation of
the Kaito ferry service and to serve other public vessels.
2.6.1.6
The temporary pier will be located at the pier head of the existing pier
as shown in Image 2.15. The proposed
temporary pier is in the southeast of the existing pier and is about 20m long
and 5.5m wide. The currently proposed location has considered the
distribution of coral colonies within the proposed pier improvement area and
will have the least impact on coral colonies. The final arrangement of the
temporary pier will be determined during the construction stage by the
contractor to suit their final method and programme of construction. The pier will be in the form of floating pontoon and/or
steel structures supported by piles to minimise any environmental impact. The
temporary pier will be demolished after completion of a new berth of the pier.
2.6.1.7 The pier improvement work is anticipated to be divided into 2 stages. The 1st stage (Image 2.16) is to construct the proposed ramps, floating pontoon and associated structures. As the works area of 1st stage work might affect the normal operation of the existing pier if there was no temporary pier. Therefore, to enhance site safety during the construction work, a temporary pier is proposed to further separate the berthing location and the actual site works. After completion of 1st stage construction work, the proposed pontoon can allow berthing of vessels and this allows removal of the temporary pier for 2nd stage construction work and complete the whole construction work.
|
|
Image 2.16 Temporary
Pier Arrangement
Ramp Width
2.6.1.8 According to the Barrier Free Access Design Manual published by the Buildings Department, the width of a ramp should be at least 1.5m to allow 2 wheelchairs to pass. The pier improvement provides a 2m of clearance for passage of 2 wheelchairs and a 0.5m of width for the installation of handrails and fenders on both sides.
2.6.2 Construction Sequence
2.6.2.1 Project-specific site investigation will be carried out before construction work. Vertical boreholes will be carried out for the proposed TPC Public Pier. Before commencement of the work, the legs of barge and boreholes location will be inspected by diver survey to ascertain no coral colonies will be affected as far as practicable.
2.6.2.2 Prefabrication method will, if possible and applicable, be used for the construction of the proposed TPC Public Pier. The preliminary construction sequence for the proposed TPC Public Pier is as follows:
Construction of Temporary Pier
(1)
Install piles;
(2)
Install working barge and/or temporary steel structures; and
(3)
Connect the temporary pier to existing pier head.
Construction of Piles and Floating Platform
(1)
Install pile foundation/guide piles for the new pier;
(2)
Erect temporary bracing to stabilise piles; and
(3)
Install precast beams;
(4)
Install precast slab panels;
(5)
Transport the prefabricated floating platform;
(6)
Install the guide pile frame on the prefabricated floating platform to
the guide pile for mooring;
(7)
Transport the prefabricated gangway; and
(8)
Fix the gangway on the landing and rest on the floating platform.
2.6.2.3 Due to the location of the site, construction materials will be delivered via marine access. They will be transported by barges and installed using derrick barges and/or multi-purpose jack-up barge and/or temporary steel structures.
2.6.2.4 The prefabricated floating platform and gangway will be delivered via marine access. They will be transported by barges and/or derrick barges, and will be installed on site.
Demolition of Temporary Pier
(1)
Demolish the steelworks of temporary pier superstructures in pieces;
(2)
Transport the demolished steelworks off site;
(3)
Cut and remove the piles as close as possible to the seabed; and
(4)
Transport the removed piles off site.
Construction of Piled Foundation and Modification
Work of Existing Pier
(1)
Install pile foundation/guide piles for the proposed TPC Public Pier;
(2)
Demolish part of the existing pier;
(3)
Erect temporary bracing to stabilise piles; and
(4)
Install precast pile caps.
Construction of Pier Superstructure
(1)
Install precast beams;
(2)
Install prefabricated reinforcement cages;
(3)
Install precast fender blocks;
(4)
Install precast slab panels;
(5)
Install precast staircase;
(6)
Install prefabricated rebar for top slab and connect the top slab and
the fender blocks; and
(7)
Install bollards, fenders and remaining works and provide associated
facilities.
2.6.2.5 All the precast units will be delivered via marine access. They will be transported by barges and/or derrick barge, and will be install in-situ on site.
2.6.3 Consideration of Environmentally Conscious Construction Methodologies
2.6.3.1 Potential environmental impacts have been duly considered and assessed throughout the EIA stage to avoid the adverse environmental impacts of the Project. As such, environmentally conscious construction methodologies have been adopted to avoid, minimise and mitigate environmental impact from the Project as far as practicable.
Use of Double Casings
to Confine Pollutants during Bored Pile Construction
2.6.3.3
To avoid the potential water
quality impact, the foundations of the proposed TPC Public Pier and the
temporary pier will be composed of in-situ
bored piles or similar pile types (e.g. rock socketed Steel H-pile). The
proposed construction method has totally avoided the need of open sea dredging.
For each pile construction, an outer casing shall be first placed on
the seabed level to avoid spillage of suspended solids (SS) during piling
works. In comparison with the
conventional marine pile construction by single casing system with silt
curtain, it is proposed the Project adopted a more rigid steel-made outer
casing as a replacement of silt curtain. The outer casing can completely isolate the internal drilling fluid
and the outer water body, whereas the silt curtain can normally achieve
75% reduction of dispersion of suspended solids. In addition, by using the rigid
outer casing, potential injury to coral due to dragging effect of silt curtain
by tide and wave actions can be avoided. Besides, a
Y-shaped funnel (around 2 times the pile casing diameter in size) will be
installed on top of the outer casing and a closed grab excavator will be used. The barge receiving
the grabbed materials will be located as close to the pile casing as possible
and underneath the Y-shaped funnel to avoid the grabbed materials from
accidentally dropped into the surrounding water body. All grabbed materials will be conveyed to and be settled in the
sedimentation tank, and will be sequentially delivered to the designated
disposal outlets by marine transportation. Hence, the practical measures to
avoid grabbed materials making in direct contact with the open sea water would
be implemented. An illustrative figure of the setup of a marine bored pile
construction is shown in Image 2.17.
2.6.3.4 The proposed piled foundation system has been adopted in other similar projects such as the reconstruction of the Sharp Island Pier and construction of Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road (see Section 5.4). From the experience of these projects, environmental performance by this construction methodology is certain. Hence, water quality and ecological impacts can be better controlled.
Image 2.17 Outer Casing for Marine Piling Construction
Prefabrication
Construction Method
2.6.3.5 For the proposed new pier, the above-water construction works would involve the establishment of concrete structures of typically about 6m wide, increased to 15m at the head, and around 26m long above the sea. Prefabrication approach will be considered when designing concrete superstructures. Selected concrete superstructures will be formed by pre-cast concrete offsite in a controlled environment and installed onsite when ready. This can avoid on-site casting activities that could have potential impact on water quality by minimising the storage of casting materials. Moreover, this approach can minimise the extent and duration of on-site construction activities. The prefabrication method also minimises the waste generation on-site during the construction phase. As a result, the air quality, noise, water quality impacts and waste implications associated with these construction activities including emissions, site run-off, accidental spillage of chemicals and sewage from workforce could thus be avoided or minimised in comparison with on-site casting method.
2.6.4 Preferred Construction Methodology for Site Investigation Work
2.6.4.1 Vertical boreholes will be carried out on a small jack-up barge. When there is adequate water depth, the barge will be towed by tug boats to the proposed borehole locations. Before positioning, the legs of barge and boreholes location will be inspected by diver survey to ascertain no coral colonies will be affected as far as practicable. The barge will then be jacked up to above the high tide level by extending its four supporting legs onto the seabed.
2.6.4.2
Illustrative diagram of the
setup of a vertical borehole drilling rig on the barge is shown in Image 2.18. An outer casing
shall be first placed on the seabed level to avoid spillage of sediment and
water containing suspended solids (SS) during drilling work. Throughout the
drilling process, a rotary core with a drill bit is advanced inside the outer
casing to the seabed and the soil sampler cuts and collects the soil cores.
After that, an inner casing (around 168mm dia.) will be advanced to the drill
bit tip level to support the ground and seal off the open fissures. The drill
bit with the sampler with then be brought to the barge and the soil samplers
would be collected for further laboratory tests. After removal of the sample,
the rotary core with the drill bit will be once again returned to the base of
the hole for subsequent sampling works.
|
|
Image 2.18 Illustrative Diagram of Vertical Boreholes
2.6.5 Preferred Construction Methodology for the Proposed TPC Public Pier
Pile Installation Works
2.6.5.2
The foundations of the proposed TPC Public Pier and the temporary pier
will be composed of in-situ bored piles or similar pile types (e.g. rock
socketed Steel H-pile). A working platform in form of a
working barge and/or temporary steel structure supported by mini-piles (~219 or
273mm dia.) will be adopted to facilitate the pier construction works. Working
barge will be fixed in a position by anchoring concrete mooring sinkers onto
the seabed while the mini-piles used to support the temporary steel structure
would follow the confined pile casing method as discussed in Section 2.6.3.2 to Section 2.6.3.3 in order to control the water quality and ecological impacts. The sinkers
locations will be inspected by diver survey to ascertain no coral colonies will
be affected as far as practicable before anchoring. Minimal disturbance of
existing seabed would be resulted but significant dispersion of suspended
solids is not expected.
2.6.5.3 For each pile construction, confined pile casing method as discussed in Section 2.6.3.2 and Section 2.6.3.3 would also be followed. Inner casing of approximately 0.8-1.0m in diameter will be installed into the seabed by using hydraulic oscillator from a working platform. Pile shaft excavation by using hammer grab will be carried out within the casing. Closed grab excavator will be deployed to minimise the leakage of material collected during the process. The grabbed material will be bought to and be settled in the sedimentation tank. The steel casing will then be jacked down into the ground by oscillator prior to carry out next grabbing process until reaching rockhead. Reverse Circulation Drill (RCD) will be deployed to drill through the bedrock and any hard material encountered until reaching the required level. No grabbed material will made in direct contact with the open sea water.
Pier Deck Structures
Construction
2.6.5.5
Once the piles are installed, the precast elements of the pier structure
including precast pile caps, beams, walls and slabs will be transported to the
site by barges for subsequent erection, installation and in-situ stitching/casting. These precast elements could be shells
of the elements to enable in-situ
casting of the remaining concrete portions without the need of formwork and
avoiding leakage of wet concrete out of conventional formwork.
2.6.5.6 Following the completion of the deck structure, other superstructure and ancillary elements including the canopy, handrailing and seats can be transported to the site for installation. The canopy structure can be partly prefabricated off site.
2.6.6 Preferred Construction Methodology for the Proposed Temporary Pier
2.6.6.1 Piled foundation for the proposed temporary pier will be installed in the similar fashion as the piled foundation for the new pier as described in Section 2.6.5.1 and Section 2.6.5.4.
2.6.6.2 Temporary pier might be in a form of floating pontoon and/or steel structures supported by piles to maintain the marine access to Tung Ping Chau and subject to the Contractor’s proposal.
2.6.7 Demolition of the Proposed Temporary Works
2.6.7.1 Temporary pier deck structure and/or working platform will be removed piece by piece, and will be transported off site by marine transportation.
2.6.7.2
Piled foundations for temporary
use will be cut by wire saw, blade saw and similar method as close as possible to the seabed,
and the demolished portions of the piled foundations will be removed off site. Compared with the use of pneumatic breaker, the use of wire
saw or blade saw incur much lower level of vibration. The wire saw will not
disturb the seabed. The portions of the piles embedded in the ground will
be left untouched below the seabed. The estimated length of pile below seabed
is about 10m.
2.6.8 Maintenance Dredging
2.6.8.1 It is not expected to carry out maintenance dredging during both construction and operational phases as the proposed TPC Public Pier would be provide sufficient water depth for vessels to berth. The adoption of pile foundation supporting pier deck structure also contribute to the unlikelihood of maintenance dredging.
2.7.1.1 Whilst a number of design initiatives have been proactively implemented to tackle various environmental challenges, the Project aims to achieve more than the statutory requirements. Thus, various environmental initiatives have been identified for the Project. These initiatives cover different aspects including:
· Clean energy / energy saving;
· Waste minimisation; and
· Enhance biodiversity / greening.
2.7.1.2 However, whilst these initiatives are generally considered as practicable at this stage, the extent of applications and other details have to be revisited and further established during the detailed design stage when the engineering design is further developed. Table 2.4 summarises all those environmental initiatives envisioned at this stage.
Table 2.4 Environmental initiatives to be further developed during detailed design stage
|
Aspect |
Environmental Initiatives |
Environmental Benefits |
|
Enhance
biodiversity |
·
Priority
using eco-tiles or eco-concrete for the surface of the foundation. |
·
Promote
seamless integration of biodiversity into the pier design |
|
Clean
energy / energy saving |
·
PV
panels (e.g. for lights at waiting area) ·
Priority
using of LED lighting |
·
Use of
solar energy and energy-saving equipment to minimise energy consumption |
|
Waste
minimization |
·
Make
use of felled trees to produce seats at waiting areas of the pier ·
Use
recycle glass bricks for pavement |
·
Promote
the use of recycled materials / products |
2.7.1.3
Subject to the detailed design
of the Project, eco-tile or eco-concrete is recommended for the provision of
hard surfaces for vitalising the ecological functions at sub-tidal artificial
pier structures such as the downstand
wall and piles. The uneven surfaces or
selected patterns of eco-tiles provide microhabitats for various marine
organisms to colonise and grow, and develop into communities to provide feeding
and hiding habitats for juveniles of marine fauna, and thereby effectively
enhance biodiversity and ecosystem functions of the new man-made structures. During
the detailed design of the Project, the feasibility, detailed design and the
implementation programme of the eco-tile or eco-concrete will be submitted for
the approval of the authority before commencement of the works.
2.8
Collating and Addressing Public Views
Support from
Village Representatives and Sai Kung North Rural Committee
2.8.1.1
This
project has been fully discussed with members of SKNRC and the villagers-elected
VRs of the five villages on TPC. Two consultation meetings were held in 2019 to
explain the proposed design and collate views from the stakeholders.
2.8.1.2
All the VRs and members from SKNRC showed full support
to the project due to the safety condition occurring at the existing pier. During
the consultation, they revealed that the existing landing steps are too steep
and narrow where accidents happened before. Thus, they strongly support the
Project to ensure a safe embarking/disembarking environment for the
passengers/villagers.
Support from
Tai Po District Council
2.8.1.3
The Project
first discussed in Transport and Traffic Committee (TTC) of TPDC on 12 May 2017
under Pier Improvement Program (Ref. Paper no. TPDC TT 17/2017). Councillors
supported the improvement works due to the existing pier cannot cater the
increasing demand of the use of pier. Also, they concerned about the provision
of barrier-free facilities which are missing in the existing pier.
2.8.1.4
There were
meetings held in 2019 and 2020 with relevant District Councillors and they
supported the Project with concerns about the typhoon resistance of
pontoon-gangway design and the safety use of pontoon. On 25 May 2020, the Project
was discussed on TTC of TPDC (Ref. Paper No. TT 28/2020). There was a
councillor raised questions about the ecology issues at Tung Ping Chau,
including the coral and Green Turtles. Project
Proponent responded that an ecological survey had been carried out with a coral
mapping which such data would be included in the EIA report for public
inspection.
2.8.1.5
Project
Proponent explained that in general, the coral density near the existing pier
area is relatively lower than other coastal area at Tung Ping Chau. The
proposed preliminary design at the existing pier location is the most
appropriate location choice among others to minimise the influence on coral
communities.
2.8.1.6
Also, the construction
works would be suspended whenever a Green Turtle is seen as suggested by
Project Proponent and the District Councillor reminded to strictly follow this
suggestion when the works commenced.
2.8.1.7
A
councillor strongly requested to improve the pier as soon as possible since the
villagers encountered a dangerous situation years ago. Being the only access
point on the island yet the landing steps were too steep and narrow, the
villagers nearly fell into the sea when they were transporting bulky goods, for
example, daily necessities and coffins for burying indigenous inhabitants.
2.8.1.8
TPDC gave endorsement
to the Project for way forward.
Comments Received from Green Groups
2.8.1.9
There were two consultation meetings
with green groups in August and October 2019. In the first meeting, the
attendees suggested the initial proposed preliminary design was substantially
large and required Project Proponent to re-consider the footprint area of the
proposed preliminary design. After that, the Project Proponent minimized the
footprint area in responded to comments received from the first meeting and
therefore a second meeting was held.
2.8.1.10
There were attendees suggested that TPC was one of the
important coral sites in Hong Kong as well as an environmentally sensitive area
such that Project Proponent should consider carefully about the mitigation
measures to maintain the habitat for marine life.
2.8.1.11
Some green groups representatives concerned about the
number of visitors may increase and therefore burden the handling capacity of
the island so as the increase of man-made pollution. Project Proponent
responded that after consulting related Government Departments, there is no
plan to intensify the existing ferry/Kaito services. Therefore, an increase in
visitors to the island is not anticipated in the Project.
2.8.1.12
There were comments about the visual appearance of the
proposed pier structure considering TPC is also known for its geographical
features. Project Proponent responded that the appearance such as color and
canopy design would be in harmony with the environment nearby.
Comments Received During
the EIA Process
2.8.1.13
During the course of the EIA
study, comments obtained from consultations with Marine Park Committee, green
groups and members of the public have been duly revisited and were incorporated
in the design, construction and operation of the Project where appropriate. Table 2.5 summarises all these comments
and how the Project Proponent has addressed them suitably.
Table 2.5 Summary of key comments and approaches adopted to address comments collated
|
Issues |
Comments |
Responses & Approaches Adopted |
|
General |
Given the pier was repaired years ago,
Project Proponent and his team shall explain clearly about the needs of the
improvement work. |
In 2017 Policy Address, the Government
committed to improve a number of remote public piers to facilitate public
access to outing destinations. While
repair work was carried out at TPC Public Pier in 2008, it only involved the
reconstruction of the catwalk due to the deteriorated structural condition
and other parts of the pier were not revamped. Also, the proposed improvement work was
necessary because the current boarding/ landing facilities of the pier were
below standard and unsafe for the embarking/ disembarking of passengers. |
|
Since the pier is usually used by
villagers, it is suggested to provide landing steps closer to the shore to
reduce the walking distance. |
The existing landing step at the pier head
of TPC Public Pier would be retained considering the high usage rate. The
result of coral survey found that the closer to the shore of TPC Public Pier,
the higher the coral density. In view of that, building landing steps near
the shore was not suggested. |
|
|
The necessity to "further
improve" the present large, substantial and 'very modern' Tung Ping Chau
pier is highly doubtful. The project proponent shall provide justification of
the improvement work. |
Noting that the conventional mechanism of
taking forward improvement works of public piers under the Public Works
Programme is primarily based on utilisation rate which is less favourable to
piers serving remote areas, the Government introduced in 2017 a new policy
initiative, Pier Improvement Program (PIP),
aiming at improvement of existing public piers at some remote areas,
which have benefits to the public but relatively low utilisation rates
(especially during weekdays). TPC public pier is one of the 10 piers in
the first batch of the PIP. There are two flights of landing steps at TPC
public pier which are narrow and steep with 1.1m wide only compared to 2m for
standardized landing. Also, its pier head is short with 14m long only when
compared to 25-30m long for vessels commonly seen. These two conditions lead
to an unsatisfactory berthing situation and bring safety concerns to the
passengers. |
|
|
Ecology |
The footprint area of the proposed preliminary
design was considered substantially large; Project Proponent shall consider
minimizing the footprint area as far as possible. |
The proposed preliminary layout has been
minimized with respect to comments from green groups to avoid the impact on
coral as far as practicable. The evolution of design layout is discussed in Section 2.5. |
|
There are concerns about the translocation
plan of coral communities particularly the reasons for suggesting Wong Ye
Kwok as a potential recipient site for coral translocation. Project Proponent
shall provide the coral translocation plan for review. |
Wong Ye Kwok was one of the locations for
Hong Kong Reef Check and its environment was suitable for coral growth. They believed that the translocated coral
colonies would have a higher rate of survival if they were translocated to
Wong Ye Kwok. Moreover, the Contractor would be required to provide a
specific coral translocation plan, including the selection of a suitable site
for coral translocation, and in the site selection process, to consider
factors like coral density and possible effect on the original coral
communities there. |
|
|
Project Proponent should provide the
details of how the coral mapping was conducted and results. |
For the detailed of the coral mapping
please refer to Section 8. |
|
|
TPC was one of the important coral sites in
Hong Kong. Project Proponent should consider
adding features that could enhance marine biodiversity on the piles of the
piers and making the catwalks a light penetrating structure in an effort to
encourage the growth of algae under the pier and create a better habitat for
marine life. |
Eco-tiles could be considered to place and
incorporate into the designs at the detailed design stage to enhance the
biodiversity of marine and intertidal habitats. Continuous liaison with the
parties will be made during design development. |
|
|
Water Quality |
The new structures may disturb the water
current and sedimentation hence affect the water quality. |
In the proposed preliminary design, the
foundation of the new pier structures would allow water to pass through,
thereby reducing the impact on water current and sedimentation. Potential hydrodynamic impact from the new
pier structure has been duly assessed in the EIA study. Pile columns have
been used as the supportive piles with sufficient column-to-column spacing
provided to allow flow of water current. |
|
Project Construction |
It is concerned that
vibrations from the piling works would affect the marine species around the
areas. |
Instead of adopting
percussive piling for pile construction, bored piling method will be adopted
to minimise the noise and vibration from the piling works of the Project. |
|
There are concerns about
demolishing of temporary pier may bring pollution to the areas nearby. |
The main superstructure
of the temporary pier will be mostly made of steel. Dismantling of the pier
on-site is not required. For the supportive piles of the temporary pier, the
contractors would be asked to cut the piles off as close to the seabed as
possible and not to remove the piles inserted below the seabed to prevent
damaging the seabed. Also, the proposed pile cutting method was used in the demolishing
of the temporary pier for the recently reconstructed Sharp Island Pier. |
|
|
Project Operations |
The number of visitors may increase and
therefore burden the handling capacity of the island so as the increase of
man-made pollution. |
After consulting related Government
Departments, there is no plan to intensify the existing ferry/Kaito services.
Hence, an increase in visitors is not anticipated in this Project. |
|
Sustainability |
Renewable energy should be deployed as much
as possible in this development project to support electricity support on the
pier. |
Renewable energy has been explored during
the EIA study. Environmental initiatives including but not
limited to renewable energy will be implemented during detailed design of the
Project. Details are discussed in Section
2.7. |
2.9 Tentative Implementation Programme
2.9.1.1 A tentative programme for the construction of the project is shown in Appendix 2.1. Site Investigation works for detailed design will be carried out from Q4 2021 to Q1 2022. Prefabrication method will be adopted as far as practicable for the construction works. Construction is scheduled to commence in Year 2023 and completed by Year 2026. Construction works are planned to be carried out during non-restricted hours (i.e. 0700-1900 hours from Monday to Saturday other than public holidays). The exact schedule of construction depends upon factors such as the granting of necessary permit for its construction and the awarding of the contract to the contractor.
2.10.1.1 There are two concurrent projects which may bear potential environmental impacts during the construction and operational phases of the proposed Project. These concurrent projects are identified as follows.
·
Solar Power and Small Wind Turbine Project
by the China Light & Power (CLP); and
·
Desalination Project at Tung Ping Chau by
Environmental Association Limited.
2.10.1.2 Detailed justifications on consideration of various environmental cumulative impacts from concurrent projects have been included in corresponding sections.
Solar Power and Small Wind Turbine Project
by CLP
2.10.1.3 As mentioned in Project Profile (PP-562/2017) of this Project that CLP has planned the provision of solar power and small wind turbine in TPC. CLP was contacted in October 2019 to seek for more information regarding this concurrent project. From their correspondence, this concurrent project is still under the inception stage and the programme is yet to be confirmed. Therefore, cumulative impacts from this concurrent project are not anticipated in both construction and operational phases.
Desalination
Project at Tung Ping Chau by Environmental Association Limited
2.10.1.4 Environmental Association Limited is currently planning the provision of small desalination units at TPC. These desalination units will be installed at Chau Mei which is located outside the 500m from the boundary of the present Project. The locations of these concurrent projects are illustrated in Appendix 2.2. The provision of the small desalination units does not require construction works. The units will be deployed in the village in between Q3 2020 and Q4 2020. Cumulative impact is therefore not anticipated.
2.10.1.5 As regards the operation, there will be no active intake pumps for these desalination units. The villagers will do the water desalination manually. Soak away method will be adopted for the concentrate to drain slowly and no direct discharge is required from this concurrent project. Cumulative impact is therefore not anticipated during the operational phase of this concurrent project.
Table 2.6 Potential impacts of concurrent projects
|
Project Proponent |
Programme |
Potential Cumulative
Impacts (Construction Phase) |
Potential Cumulative
Impacts (Operational Phase) |
||
|
Start |
Complete |
||||
|
Present
Project (Site Investigation Works for Detailed Design) |
CEDD |
End-2021 |
Early-2022 |
NA |
NA |
|
Present
Project (Pier Improvement Works) |
CEDD |
2024 |
2026 |
NA |
NA |
|
Solar Power and Small Wing Turbines Project |
CLP |
No information |
No information |
No
information |
No
information |
|
Desalination Project at Tung Ping Chau |
Environmental
Association Ltd. |
Q3 2020 |
Q4 2020 |
Desalination unit will be deployed. No
construction works are required. Therefore, no cumulative impacts are
anticipated. |
As the marine ecological impact brought by the
Project is anticipated to be insignificant, no significant cumulative impact
during the operational phase is anticipated. |
Note:
[1] NA – Not Applicable
2.11 Summary of Environmental Benefits and Environmental Achievements of the Project
2.11.1.1
Throughout
the EIA study, site constraints and impacts have been identified and assessed
and mitigation measures/good site practices, if necessary, have been
recommended to avoid negative environmental impacts to the surroundings. In addition, comments from district councils, residential, green groups
and other stakeholders have also been reviewed and incorporated where
practicable. A number of environmental initiatives covering good managing
practices, waste minimisation and natural conservation have been recommended
for incorporation in the detailed design.
2.11.1.2
A
summary of the key environmental benefits and achievements of the Project is
given in Table 2.7 for reference:
Table 2.7 Key Recommended
Mitigation Measures/Good Site Practices/Enhancement Measures and their
Associated Benefits
|
Key recommended mitigation measures/good site
practices/enhancement measures |
Associated Benefits |
|
|
Air
Quality |
·
Routing
of barges should be as far away from the identified Air Sensitive Receivers
(ASRs) as practicable. ·
The
number of boat trips should be minimised as far as practicable by appropriate
planning. |
·
Protect air sensitive receivers by reducing fugitive
dust emission |
|
Noise |
·
Use of Quality
Powered Mechanical Equipment (QPME). ·
Use of temporary
noise barriers to screen noise from relatively static Powered Mechanical
Equipment (PME). ·
Alternative use of
plant items within one worksite, wherever practicable. |
·
Protect noise
sensitive receivers by reducing construction noise impact |
|
Water
Quality |
·
Water quality
monitoring. ·
Adoption of good
site practices for foundation works, such as adopting double casing system,
to avoid and minimize the release of suspended solids. ·
Excavation should only
be conducted inside pile casing. Only one closed grab should be used at the
same time. ·
Only 1-2 piles to be
constructed at the same time. ·
Prefabrication
construction method should be adopted as far as practicable. ·
Contractor to prepare Emergency Spillage
Plan for accidental spillage of chemicals. |
·
Protect the
neighbouring water sensitive receivers in particular coral communities |
|
Waste
Management |
·
Good waste
management and control practices to avoid generation of excessive amount of
waste materials. ·
Employ
waste collectors for disposal of general refuse to prevent potential nuisance
caused by mistreating general refuse, such as windblown, vermin, water
pollution and visual impact. |
·
Minimise
waste generation ·
Ensure
proper handling of chemical waste |
|
Land
Contamination |
·
No
mitigation measures would be required. |
·
No land
contamination anticipated |
|
Ecology |
·
A coral
translocation programme comprising a pre-translocation coral survey, coral
translocation and post-translocation coral monitoring will be implemented to
minimise the number of corals being encroached or impacted by reduction of
sunlight. ·
Conduct
diver survey when placing legs of jack-up barge or concrete mooring sinkers. ·
Set up
marker buoys to restrict construction vessels in the marked areas. ·
No overlap of new location of the construction
vessels with its original location to allow more light penetration for
corals. ·
Priority using
eco-tiles or eco-concrete for the surface of the foundation to promote
seamless integration of biodiversity into the pier design |
·
Translocate
the coral colonies under the proposed pier footprint ·
Minimise
the impact to coral in proximity to the Project ·
Enhance
biodiversity of the site |
|
Landscape and Visual |
·
Sensitive design and
disposition of the pier structures to minimise visual intrusion to VSRs as
far as practicable. |
·
Enhance the visual
appearance for the operational phase |
|
Fisheries |
·
Adoption of good site practices for water quality in marine works to
ensure no adverse fisheries impact would be anticipated. |
·
Protect
fisheries resources |
|
Cultural Heritage |
·
No mitigation measures would be required. As a precautionary measure,
Antiquities and Monuments Office (AMO) should be informed in case of
discovery of antiquities or supposed antiquities in the course of marine
works. |
·
No impact
of cultural heritage anticipated |