10.1
This section identifies the
types of waste which are likely to be generated during the construction and
operation phases of the Project, and evaluates the potential environmental
impacts that may result from waste generated during these phases.
10.2
Mitigation measures and good
site practices, including waste handling, storage and disposal, have been
recommended with reference to relevant waste legislation and management
guidelines. Handling and disposal of contaminated
sediments has also been discussed.
10.3 The criteria and guidelines for assessing waste management implications are outlined in Annex 7 and Annex 15 of the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), respectively.
10.4
The following legislation also
cover the handling, treatment and disposal of waste in
§
Waste
Disposal Ordinance (Cap. 354);
§
Waste
Disposal (Chemical Waste) (General) Regulation (Cap. 354C);
§
Land
(Miscellaneous Provisions) Ordinance (Cap. 28);
§
Public
Health and Municipal Services Ordinance (Cap. 132) - Public Cleansing and
Prevention of Nuisances Regulation;
§
Waste
Disposal (Charges for Disposal of Construction Waste) Regulation (Cap. 354N);
and
§
Dumping at Sea Ordinance (Cap 466).
Waste Disposal Ordinance (Cap. 354)
10.5 The Waste Disposal Ordinance (WDO) prohibits any unauthorised disposal of waste. Construction waste, defined under Cap. 354N of the WDO, refers to a substance, matter or thing which is generated from construction works. It includes all abandoned materials, whether processed or stockpiled or not, before being abandoned, but does not include sludge, screenings or matter removed or generated from desludging, desilting or dredging works. Under the WDO, waste can be disposed of only at designated waste disposal facilities licensed by the Environmental Protection Department (EPD).
Waste Disposal (Chemical Waste) (General) Regulation
(Cap. 354C)
10.6 Under the WDO, the Chemical Waste (General) Regulation provides regulations for chemical waste control, and administers the possession, storage, collection, transport and disposal of chemical waste. EPD has also issued the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992), which details how the chemical waste producers should comply with the regulations on chemical waste.
Public Health and Municipal Services Ordinance (Cap.
132)
10.7 The Public Cleansing and Prevention of Nuisances Regulation provides control on illegal tipping of waste on unauthorised (unlicensed) sites.
Land (Miscellaneous Provisions) Ordinance (Cap 28)
10.8 The inert portion of Construction and Demolition (C&D) materials (including rocks, soil, broken concrete, building debris, etc.) may be taken to public fill reception facilities. Public Fill Reception Facilities (PFRFs) usually form part of land reclamation schemes and are operated by the Civil Engineering and Development Department (CEDD) and others. The Land (Miscellaneous Provisions) Ordinance requires that individuals or companies who deliver public fill to the public fill reception facilities are required to obtain Dumping Licences. The licences are issued by CEDD under delegated authority from the Director of Lands.
10.9
Individual licences and
windscreen stickers are issued for each vehicle involved. Under the licence conditions, PFRFs will only
accept soil, sand, rubble, brick, tile, rock, boulder, concrete, bitumen,
masonry or used bentonite. In addition,
in accordance with paragraph 11 of the Environment, Transport and Works Bureau
(ETWB) Technical Circular (Works) (TC(W)) No. 31/2004, Public Fill
Committee will advise on the acceptance criteria. The material will, however, be free from
marine mud, household refuse, plastic, metal, industrial and chemical wastes,
animal and vegetable matter and any other materials considered unsuitable by
the supervisor of the PFRFs.
Waste Disposal (Charges for Disposal of Construction
Waste) Regulation (Cap. 354N)
10.10 Under the Waste Disposal (Charges for Disposal of Construction Waste) Regulation enacted in January 2006, construction waste delivered to a landfill for disposal must not contain more than 50% by weight of inert material. Construction waste delivered to a sorting facility for disposal must contain more than 50% by weight of inert material, and construction waste delivered to a PFRF for disposal must consist entirely of inert material.
Dumping at Sea Ordinance (Cap 466) (DASO)
10.11
This Ordinance came into operation
in April 1995 and empowers the Director of Environmental Protection (DEP) to
control the disposal and incineration of substances and particles at sea for
the protection of the marine environment.
Under the Ordinance, a dumping permit from the DEP is required for the
disposal of regulated substances within and outside the waters of
§
Type
and quantity of substances permitted to be dumped;
§
Location
of the disposal grounds;
§
Requirement
of equipment for monitoring the disposal operations; and
§
Environmental
monitoring requirements.
10.12 Marine disposal of any dredged/excavated sediment is subject to control under the Dumping at Sea Ordinance. Dredged/excavated sediment destined for marine disposal is classified based on its contaminant levels with reference to the Chemical Exceedance Levels (CEL), as stipulated in Practice Note for Authorised Persons and Registered Structural Engineers 252 Management Framework for Disposal of Dredged/ Excavated Sediment (PNAP 252). This Practice Note includes a set of sediment quality criteria, including heavy metals and metalloids, organic pollutants and a class of contamination level for highly contaminated sediment not suitable for marine disposal.
10.13 Other guidelines which detail how the Contractor should comply with are as follow:
§
A Guide to the Registration of Chemical
Waste Producers, Environmental Protection Department,
§
A Guide to the Chemical Waste
Control Scheme, Environmental Protection Department,
§
Code of Practice on Package,
Labelling and Storage of Chemical Wastes (1992), Environmental Protection
Department,
§
Works
Branch Technical Circular (WBTC) No. 2/93, Public Dumps;
§
Works Branch Technical Circular No. 2/93B, Public Filling
Facilities;
§
PNAP
252, Management Framework for Disposal of Dredged/ Excavated Sediment;
§
ETWB TC(W) No. 33/2002, Management of
Construction/Demolition Materials including Rocks;
§
ETWB TC(W) No. 31/2004, Trip-ticket System for Disposal
of Construction and Demolition Materials; and
§
ETWB TC(W) No. 19/2005, Environmental Management on
Construction Sites.
10.14 Current policy related to the disposal of C&D materials is documented in the WBTC No. 2/93, ‘Public Dumps’. C&D materials that are wholly inert, namely public fill, should not be disposed of at landfill, but be taken to PFRFs, which usually form part of reclamation schemes. The Land (Miscellaneous Provisions) Ordinance requires the dumping licenses to be obtained by individuals or companies who deliver public fill to PFRFs. The CEDD issues the licenses under delegated powers from the Director of Lands.
10.15 In accordance with the ETWB TC(W) No. 31/2004 ‘Trip Ticket System for Disposal of Construction and Demolition Materials’, all contracts that are expected to generate inert C&D materials (e.g. soil, broken rock, broken concrete and building debris, etc) requiring disposal from site, the project office shall write to the Public Fill Committee (PFC) through Secretary of the PFC to request a designated disposal ground for incorporation into the tender documents. For contracts where the estimated amount of non-inert C&D materials requiring disposal at landfill facilities equal or exceed 50 m3, the project office shall seek confirmation from the DEP in terms of the availability of landfill facilities for disposal of such materials. The DEP will designate landfill facilities, if available, for the contract. Where the estimated amount of non-inert C&D materials to be generated from the contract is less than 50 m3, the project office is not required to apply to DEP for designated landfill facilities. However, the project office should still specify in the tender documents of the appropriate landfill facilities (e.g. SENT Landfill at Tseung Kwan O, NENT Landfill at Ta Kwu Ling and WENT Landfill at Nim Wan) for disposal.
10.16 Further measures are introduced under ETWB TC(W) No. 33/2002, that management of C&D materials, including rocks are strengthened and their generation at sources are minimised. The enhancement measures include: (i) drafting of a Construction and Demolition Material Management Plan (C&DMMP) at an early design stage to minimise C&D materials generation and encourage proper management of such materials; (ii) vetting of the C&DMMP prior to upgrading of the project to Category A in the Public Works Programme; and (iii) providing the contractor with information from the C&DMMP in order to facilitate the preparation of the Waste Management Plan (WMP) and to minimise C&D materials generation during construction. Projects generating C&D materials or importing fill material less than 50,000 m3 are exempted from the C&DMMP.
10.17 The PNAP 252 Management Framework for Disposal of Dredged/Excavated Sediment sets out the procedure for seeking approval to dredge/ excavate sediment and the management framework for marine disposal of dredged/ excavated sediment for all private projects. This Practice Note outlines the requirements to be followed in assessing sediment quality and classifying the sediment and explains the marine disposal arrangement for the classified material. The sediment quality criteria for the classification of sediment with reference to Lower Chemical Exceedance Level (LCEL) and Upper Chemical Exceedance Level (UCEL) are presented in Appendix A of PNAP 252.
10.18 In accordance with PNAP 252, sediment is categorised with reference to the LCEL and UCEL, as follows:
§
Category L - Sediment with all contaminant levels not
exceeding the LCEL. The material must be dredged, transported and disposed of
in a manner that minimises the loss of contaminants either into solution or by
resuspension.
§
Category M - Sediment
with any one or more contaminant levels exceeding LCEL and none exceeding
UCEL. The material must be dredged and
transported with care, and must be effectively isolated from the environment
upon final disposal unless appropriate biological tests demonstrate that the
material will not adversely affect the marine environment.
§
Category H - Sediment with
any one or more contaminant levels exceeding the UCEL. The material must be dredged and transported
with great care, and must be effectively isolated from the environment upon
final disposal.
10.19 In case of Category M and Category H (with level exceeding 10 times LCEL) contamination, Tier III screening (biological screening) should be conducted to identify the most appropriate disposal option for Category M and certain Category H sediments. A test proposal should be submitted for approval to DEP and copy to the Secretary of Marine Fill Committee (MFC).
10.20
Procedures as stipulated under
PNAP 252 should be followed if marine disposal of dredged/ excavated sediments
is involved. The final determination of appropriate disposal options, routing
and the allocation of a permit to dispose of material at a designated site will
be made by EPD and the MFC in accordance with
Assessment Approach and Methodology
10.21 The criteria for assessing waste management implications are outlined in Annex 7 of the EIAO-TM. The methods for assessing potential waste management impacts during the construction and operation phases of the Project follow those presented in Annex 15 of the EIAO-TM and including the following:
§
Estimation of types and quantities of the waste generated;
§
Assessment of potential impacts from the management of the
waste with respect to potential hazards, air and odour emissions, noise,
wastewater discharge and public transport; and
§
Impacts on the capacity of waste collection, transfer and
disposal facilities
10.22 Opportunities for waste reduction have been assessed based upon the following:
§
Avoidance and minimisation of waste generation throughout
the design stage;
§
Segregation of waste materials would be promoted and considered
as the best management practices;
§
Reuse and recycling on site or on other projects; and
§
Material diversion to public fills and landfills, which are
the last resorts of waste management.
10.23 Types and quantity of waste generated has been estimated and the disposal options have been identified according to the relevant legislations and guidelines. Environmental implications on handling, collection and disposal of waste materials have also been considered.
Identification of Waste Sources
10.24 The construction works would commence in December 2009 and the overall project completion is anticipated to be in 2015. The types of waste generated and their respective sources during the construction phase and operation phase are tabulated in Table 10.1.
|
Waste
Types |
Sources
of Waste Identified |
Examples |
|
Construction Phase |
||
|
Construction and Demolition
(C&D) Materials |
Ÿ Excavated materials, generated
from TBM, Drill & Blast (D&B) methods and Cut-and-Cover (C & C)
Method Ÿ Materials from site
formation and demolition works |
Ÿ Inert C&D materials (i)
Hard materials - Rocks (granites &
volcanics) - AHM (such as broken concrete, bitumen and steel) (ii)
Soft materials -
Soft inert materials (fill etc.) (iii) Wet Spoil Ÿ Non – inert C&D materials |
|
Sediments |
Ÿ Dredging and Excavation
Works at (i)
C & C works area for West Kowloon Terminus and
associated structures (ii)
C & C works area for Mong Kong West Ventilation Building
and C & C tunnel alignment section from Chainage 140+380 to 140+900 (iii)
C & C works area for Hoi Ting Road Construction Shaft (iv)
C & C works areas for (v)
C & C works area for Mei Lai Road Construction Shaft (vi)
River training and culverting works in stream in Shek Kong (vii)
C & C works area for Tai Kong Po Emergency Access
Point (viii)
C & C works area for (ix) Dredging area near
barging point at Lung Kwu Sheung Tan |
Ÿ Marine deposits (i)
Category L sediment (ii)
Category M sediment (iii) Category H sediment |
|
Chemical waste |
Ÿ Plant Operations and
Maintenance Ÿ Operation
of TBM machinery Ÿ Maintenance
of mechanical equipments |
Ÿ Oil and grease; scrap batteries;
used paint and cleaners etc. |
|
General refuse |
Ÿ Construction works and
site-based staff and workers |
Ÿ Food waste, containers,
cans and waste papers etc. |
|
Sewage |
Ÿ Site-based staff and
workers |
Ÿ Sludge
and night soil |
|
Operation Phase |
||
|
Chemical waste |
Ÿ Maintenance
of facilities and equipments Ÿ Renovation
work |
Ÿ Used paint, lubricants
and used batteries etc. |
|
General refuse |
Ÿ Staff and passengers |
Ÿ Food waste, containers,
cans and waste papers etc. |
|
Industrial waste |
Ÿ Maintenance activities
of ventilation buildings, SSS and WKT. |
Ÿ Scrap materials like
metals etc. |
Evaluation of Waste Impacts for Construction
Phase
10.25 The types of waste that would be generated have been shown in the following and their impacts caused would be evaluated.
§
C&D materials, including
excavated materials, materials from site formation and demolition works
§
Sediments;
§
Chemical waste;
§
General refuse; and
§
Sewage.
Construction and Demolition Materials
Excavated Materials
10.26 In the Project, excavated materials would be generated from excavation of WKT, tunnels, adits and shafts/ventilation buildings which constitute the largest proportion of the total volume of C&D materials. The types of materials include rocks, which include Grade I/II granites and rock other than grade I/II granites (grade III/IV granites and volcanics); soft materials, such as fill; and wet spoil, which is the soft materials generated from TBM excavation, diaphragm wall, bored piles installations and pre-bored H installations.
10.27 Based on the most updated C&DMMP prepared by MTRC and presented to CEDD at the meeting on 28 April 2009, Appendix 10.1 is tabulated as the breakdown of C&D materials generation based on the excavation works. According to the appendix, total volume of excavated materials generated is approximately 9,666,300 m3, including rocks, soft inert materials and wet spoil. Approximate 2,776,500 m3 of total excavated materials is rock, including grade I/II granites and rock other than grade I/II granites, which would be encountered in most of the works areas except Tai Kong Po Works Area. An estimated volume of 5,378,800 m3 is soft materials such as fill while 1,511,000 m3 would be wet spoil.
10.28
Each type of waste should be
properly sorted on-site to enhance the reusable volume. The C&D materials generated should then
be reused as far as practicable on site.
At this stage, an estimated volume of 619,900 m3 of soft
materials could be reused as backfill with possible outlets for backfilling
include Mai Po Ventilation Shaft (133,000 m3), Tai Kong Po
Construction Shaft (37,900 m3),
10.29 The surplus volume of excavated materials would require disposal. The identified disposal outlets include transportation to Taishan and PFRFs managed by CEDD. Discussion on disposal programme and routes of the materials would be presented in Section 10.57 – 10.66 below.
Materials from Site Formation and Demolition Works
10.30 Materials generated from site formation and demolition works constitute the remaining part of the C&D materials in the Project. The following materials could be generated:
§
Timber from formwork;
§
Demolition waste, such as concrete, steel etc. from the
identified structures;
§
Materials generated during site formation such as low grade
trees; and
§
Unusable/surplus concrete or grouting mixture.
10.31 A total of 18 buildings/structures will be demolished for the construction work of the Project. Apart from these buildings/structures, external walls of Kowloon Station Development and Austin Station will also need to be removed for the new subways and footbridges from the WKT.
10.32 Referring to Appendix 10.1, an estimated total of about 89,600 m3 of Artificial Hard Materials (AHM) from demolition work, such as broken concrete and bitumen, would be generated in the works areas as shown in Table 10.2. Materials recovered should be recycled or reused as far as possible. Metals, which have re-sale value, should be separated from inert C&D materials in this regard. Broken concrete with size smaller than 250mm would be disposed of at PFRFs while bitumen and broken concrete with size larger than 250mm would be crushed and then stockpiled on-site for future reuse in the Project. The possible outlet of reusing these materials would be discussed in Section 10.41 - 10.42.
10.33 Site formation works have to be carried out in preparation of the construction sites. The possible non-inert C&D materials generated from these works include trees, timbers, plastics and papers etc with an amount of approximately 29,900 m3 referring to Appendix 10.1, which would be disposed of in landfills. It is the Contractor responsibility to separate the inert and non-inert C&D materials on site. A summary on the quantity of C&D materials generated annually is tabulated in Table 10.2 below.
Table
10.2 Summary on Quantity of
C&D Materials Generated Annually
|
C&D Materials |
Approximate Quantity Generated Annually (X 1,000 m3) |
||||||
|
2010 |
2011 |
2012 |
2013 |
2014 |
Total |
||
|
Soft Inert Materials |
- |
276.6 |
3730.8 |
953.0 |
418.4 |
- |
5378.8 |
|
Rock |
Grade
I/II granites |
58.5 |
732.7 |
481.2 |
- |
- |
1272.4 |
|
Rock
other than grade I/II granites (1) |
14.1 |
148.4 |
760.6 |
581.0 |
- |
1504.1 |
|
|
Wet Spoil |
- |
358.0 |
127.3 |
834.2 |
191.5 |
- |
1511.0 |
|
Materials from Demolition Works |
Artificial
Hard Material – Bitumen |
14.0 |
1.6 |
- |
- |
- |
15.6 |
|
Artificial
Hard Material – Broken Concrete |
35.2 |
23.8 |
15 |
- |
- |
74 |
|
|
Materials from Site Formation |
Non-inert
C&D materials |
8.4 |
4.0 |
4.0 |
4.0 |
9.4 |
29.9 |
|
Sub-total |
764.8 |
4768.6 |
3048.1 |
1194.9 |
9.4 |
9785.9 |
|
Notes:
1.
Include grade III/IV
granites and volcanics of Appendix 10.1
Minimisation of C&D Materials in the Project
10.34 Owing to the combined effects from urban setting and nature of engineering constraints, the available schemes for construction of railway facilities and tunnels are limited, hindering the minimisation of waste generation. Despite of the constraints, alternative methods for construction and measures to minimise generation of C&D materials at the preliminary design stage have been investigated and adopted. These include the following:
Stations
and Approach Tunnels
10.35 The constructions of stations and approach tunnels have been carefully investigated and designed so as to reduce unnecessary excavation. It is estimated that approximately 428,000 – 447,000 m3 of spoil could be reduced with the implementation of the designs below.
§
Optimising the formation levels of the station such as WKT
to reduce excavation;
§
Active
adoption of ground filling to form the required level of the stabling sidings
which could reduce 160,000 m3 of materials;
§
Control the length of overrun tunnels by reducing from 87 to
65 for Long Haul trains, which requires close liaison with the China section of
XRL, reducing generation of 210,000 m3; and
§
Continuous coordination with
Buildings Department (BD) to reduce the number of piles by 15 – 20% which could
reduce 58,000 – 77,000 m3 of spoil.
Tunnels
§
TBM
and D&B methods would be actively employed throughout the entire length of
the tunnels to north of
Ventilation
Buildings (VBs)
10.37 Ventilation buildings serve as the role of air ventilation, emergency access by rescuers and exit for fire escape. The volume generated has been reduced by adoption of the measures below:
§
Construction
of the VBs could use the fire engineering approach in which the required size
of the VBs or the proposed Emergency Access Points (EAPs) could be minimised;
§
Access
shafts are combined with the VBs, wherever it is proved to be feasible, to
reduce the number of buildings to be constructed; and
§
Design
on the configuration of the VBs and access shafts have been critically
reviewed.
10.38 With adoption of the above measures, the total estimated volume of C&D materials arising from the construction of Project would be approximately 9,785,900 m3 as shown in Table 10.2 above. Majority of the spoil would be generated from the works at WKT and SSS.
Maximisation of Reusing C&D Materials On-site
10.39 It is of paramount importance to reuse the identified C&D materials and other wastes as far as possible to reduce total amount to be disposed of off-site. In order to maximise reuse, it is considered that the inert portion, such as fill, would be suitable as structural fill, while hard materials could be reused as general rock filling materials. Granites could be reused for concrete batching subject to tested alkalinity levels. Disposal of material to PFRFs should be considered as follow up measures and to Taishan as the last resort when the preferred approach for beneficial use of C&D materials within the Project or in other projects still cannot handle the C&D materials generated from this Project. For the non-inert portion, the materials should be recycled as far as practicable before disposal at landfills.
Recycling
Materials Generated
§
Broken concrete – generated from demolition of buildings or
structures, with the provision of on-site segregation as mentioned in Section 10.54 – 10.56, materials with particle size smaller than 250mm
could be delivered to Tseung Kwan O Area 137 for beneficial uses. Broken concrete with size larger than 250mm
should be crushed before further usage.
The processed material could then be reused for the sub-base or pipe
bedding materials, hard core or backfilling materials on-site. This material may also be reused for
production of general grade concrete as the aggregates. It is predicted that all broken concrete
generated could be reused on-site, which has a volume of approximately 74,000 m3
as refer to Table 10.4; and
§
Bitumen – generated from the demolition of structures such
as roads. As bitumen would not be
accepted by CEDD or Taishan, all the generated materials, with a volume of
estimated 15,600 m3 as refer to Table
10.5, would be stockpiled on-site for future reuse within the Project.
10.42 Other opportunities of reusing the inert C&D materials on-site have been explored; however, due to timing mismatch in the construction programme and the limited need of the Project, the volume of reuse within the Project is found to be limited. Nonetheless, possibility of reusing the spoil within the Project will be continuously investigated in the detailed design and construction stages.
Maximisation of Reusing C&D Materials Off-site
10.43 Possibilities of reusing the generated materials off-site have also been investigated vigorously , the possible outlets may include the following:
Concrete
Batching Plant
10.44
With the supply of suitable aggregates,
a concrete batching plant (CBP) would be set up at
10.45 It is anticipated that the CBP may induce dust and construction noise impacts to the surroundings during its operation and these potential impacts have been discussed in relevant sections of this report. With recommended mitigation measures in place, the impacts arising from the operation of the facilities are insignificant. As the operation of the concrete batching plant is classified as Specified Processes (SP) under the APCO, the future operation of the plant would be governed by a license.
10.46
There will be several major
infrastructures projects to be developed in
10.47 According to the latest available information, HZMB would require approximately 10,951,100 m3 of general fill (i.e. soft materials) and 2,823,000 m3 of rock fill from 2011 to 2015 on a preliminary estimation. Approximately 1,615,600 m3 and 1,647,000 m3 of soft materials and rock generated from the Project could be reused by HZMB. Due to insecure construction programme of the projects and grading of rock to be supplied by the Project will require further testing after excavation to justify the suitability of filling materials for HZMB, the estimated quantities of material in which the Project supplies would be revised with further liaison and arrangements changes.
Table
10.3 Quantity of Fill Materials
Supplied by the Project and Required by HZMB
|
Filling Materials |
Approximate Quantity (X 1,000m3) |
|||||||
|
2010 |
2011 |
2012 |
2013 |
2014 |
2015 |
Total |
||
|
Public Fill
– soft materials |
Generated
from the Project |
276.6 |
3730.8 |
953.0 |
418.4 |
- |
- |
5378.8 |
|
Amount
required by HZMB |
- |
244.6 |
7907.6 |
2445.7 |
353.3 |
- |
10951.1 |
|
|
Max. supply
to HZMB from the Project (1) |
- |
244.6 |
953.0 |
418.4 |
- |
- |
1615.6(3) |
|
|
Public Fill
– Rock |
Generated
from the Project (2) |
72.6 |
881.1 |
1241.8 |
581.0 |
- |
- |
2776.5 |
|
Amount
Required by HZMB |
- |
2056.6 |
766.0 |
- |
- |
- |
2822.6 |
|
|
Estimated supply to HZMB from the Project (1) |
- |
881 |
766.0 |
- |
- |
- |
1647.03) |
|
Notes:
1.
Preliminary estimation of
reuse in HZMB
2.
Included Grade I/II
Granites and Rock Other than Grade I/II Granites
3.
Construction programme of the
HZMB and the Project would be continuously updated and grading of rock to be
supplied by the Project would also require further testing after excavation to
justify the suitability of filling materials for HZMB, thus the estimated
quantities of material in which the Project supplies would be revised with
further liaison and arrangements changes.
Other
Potential Outlets Considered
10.50
Other possibilities of reusing
the C&D materials in concurrent projects or outlets in
§
Kai Tak development and site formation work for the Cruise
Terminal development – possibilities of provision of stockpiling area in the
area for supplying excavated materials to development projects in Kai Tak
area. Materials from the Project may be
received upon liaison with relevant government departments;
§
Lam Tei Quarry – as the Project would generate Grade III granites
which are suitable as concrete batching aggregates, one of the possibilities to
reuse the granites is delivery to the quarries for further beneficial use. This
option was considered negative because of its limited capacity.
§
Other quarries – in search of the possible outlets for
acceptance of the excavated rocks for temporary storage and permanent
rehabilitation, other quarries in
10.51 As liaison with the relevant parties as mentioned above is still on-going, the possibility of reusing the excavated materials including soil and rocks from the Project is yet to be confirmed subject to the agreement or approval from the relevant parties.
10.53
If the possible outlets in
Table
10.4 Summary on Approximate
Quantity of C&D Materials Generated, Reused and Disposed of
|
|
Soft Inert Materials |
Rocks |
Wet Spoil (2) |
Artificial Hard Material (3) |
Non-inert C&D Materials |
C&D Material (Total) |
Material Reused On-site |
Remaining Materials |
||
|
Grade I/II Granites |
Rock Other than Grade I/II Granites (1) |
Bitumen |
Broken Concrete |
|||||||
|
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X 1,000 m3 |
X
1,000 m3 |
|
|
Tunnel
between Huanggang and Ngau Tam Mei |
187.0 |
- |
- |
348.9 |
0.1 |
2.0 |
3.0 |
541.0 |
135.1 |
405.9 |
|
Tunnel
between Ngau Tam Mei and Tai Kong Po |
37.9 |
- |
389.5 (4) |
2.3 |
1.1 |
2.0 |
2.0 |
434.8 |
41.0 |
393.8 |
|
Tunnel
between Tai Kong Po and Tse |
1190.0 |
- |
- |
306.9 |
0.9 |
4.0 |
6.1 |
1507.8 |
4.9 |
1502.9 |
|
Tunnel
between Tse |
23.2 |
613.5 |
773.4 (4) |
5.4 |
0.7 |
2.0 |
2.0 |
1420.2 |
2.7 |
1417.5 |
|
Tunnel
between Shek Yam and |
- |
658.9 |
- |
- |
3.1 |
2.0 |
2.0 |
666.0 |
5.1 |
660.9 |
|
Tunnel
between |
225.0 |
- |
42.1 |
491.6 |
5.1 |
20.0 |
6.0 |
789.8 |
165.1 |
624.7 |
|
Tunnel
between Mong Kok West and |
750.0 |
- |
23.2 |
63.3 |
0.8 |
20.0 |
3.0 |
860.3 |
329.8 |
530.5 |
|
Works
at |
2965.7 |
- |
275.9 |
292.6 |
3.8 |
22.0 |
5.9 |
3565.9 |
25.8 |
3540.1 |
|
Total |
5378.8 |
1272.4 |
1504.1 |
1511.0 |
15.6 |
74.0 |
29.9 |
9785.9 (5) |
709.5 |
9076.3 |
|
Total Quantity of C&D Materials Disposed of (with materials reused in other projects and facilities) |
5813.7 (6) |
|||||||||
|
Total Quantity of C&D Materials Disposed of if all reuse
outlets exhausted |
9076.3 (7) |
|||||||||
Notes:
1. Includes Grade III/IV
granites and volcanics
2.
Generated from TBM
excavation and foundation work
3.
Generated from demolition
works
4.
Volcanics generated
5.
Total volume of C&D Materials
generated is approximately 9,785,900 m3 as shown in Appendix 10.1.
6.
It is estimated that
3,262,600 m3 materials could be reused off-site in HZMB.
These figures are subject to further confirmation with the relevant
parties and would be revised due to updated construction programme and volume
of suitable C&D materials.
1,320,000m3 of granites for reuse as concrete aggregate is
not included in disposal programme.
7.
If all reuse outlets of C&D
materials are exhausted during the construction phase, the C&D Materials
would be disposed of at Taishan as a last resort and the total volume is
approximately 9,076,300 m3 as shown in Appendix 10.2.
8.
Figures may not add up to
total due to rounding off.
On-site Sorting of C&D Materials
10.55 It is recommended that specific areas should be provided by the Contractors for on-site sorting and to provide temporary storage areas for the sorted materials. The materials could be segregated according to the categories as shown below:
§
Excavated materials suitable for
reuse on-site;
§
Excavated materials suitable for
reuse for the construction of HZMB;
§
Excavated materials for delivery to
PFRFs;
§
Excavated materials for delivery to
Taishan; and
§
Non-inert C&D materials for
delivery to landfills.
Disposal Programme for Surplus C&D Materials in Construction Phase
Table
10.5 Summary of Annual Disposal
Quantity and Quality of C&D Materials
|
Disposal Outlets |
Waste Types |
Approximate Annual Disposal Quantity(3) (X
1,000 m3) |
|||||
|
2010 |
2011 |
2012 |
2013 |
2014 |
Total |
||
|
HZMB
(1) |
Ÿ Soft
inert materials |
- |
244.6 |
953.0 |
418.4 |
- |
1615.6 |
|
Ÿ Rocks |
- |
881 |
766.0 |
- |
- |
1647 |
|
|
Taishan
(2) |
Ÿ Soft
inert materials |
276.6 |
3486.2 |
- |
- |
- |
3762.8 |
|
|
Ÿ Rocks |
72.8 |
- |
475.8 |
581.0 |
- |
1129.6 |
|
|
Ÿ
Wet Spoil |
13.9 |
11.3 |
805 |
182 |
- |
1012.1 |
|
PFRFs |
Ÿ Wet
Spoil |
344.1 |
116 |
29.6 |
9.1 |
- |
498.9 |
|
Ÿ
AHM |
49.2 |
25.4 |
15.0 |
- |
- |
89.4 |
|
|
Landfill |
Ÿ Materials
from site formation |
8.4 |
4.0 |
4.0 |
4.0 |
9.4 |
29.9 |
Notes:
1.
It is estimated that
3,262,600 m3 materials could be reused off-site in HZMB.
These figures are subject to further confirmation with the relevant
parties and would be revised due to updated construction programme and volume
of suitable C&D materials. 709,500 m3
of materials and 1,320,000 m3 of granites for possible reuse are not
included in the disposal programme.
2.
Disposal to Taishan as a
last resort if the possible outlets identified are not available during
construction.
3.
Figure may not add up to
total due to rounding off.
10.60 It should be noted that before disposal, a possible quantity of 3,262,600 m3 of materials may be reused in HZMB while 1,320,000 m3 may be reused as concrete aggregates in the concrete batching plant. Disposal should always be considered as the follow up approaches after exploration of reuse outlets. For all possible reuse outlets on-site and off-site exhausted, the remaining materials could be transported back to Taishan for beneficial use with the above stated capacity. In the latest discussion on the disposal option of materials to Taishan, with the considerations of “Reduce, Reuse and Recycle” (3Rs), Railway Development Office (RDO) of Highway Department (HyD) and CEDD has reached a consensus on the acceptance of materials to be disposed of at Taishan, owing to the lack of suitable outlets for storage of materials in Hong Kong.
10.61 After investigation of possible reuse outlet of the materials generated from site formation works i.e. non-inert C&D materials, it is estimated that all the generated volume of approximately 29,900 m3 as refer to Table 10.4 would be disposed off to designated landfills, due to the limited outlets explored. Concerning the landfill for the reception of non-inert C&D materials from the Project, EPD has agreed[1] (letter attached in Appendix 10.3) and advised that the Northeast New Territories (NENT) Landfill would be designated as the disposal outlet which could receive source separated materials with the elimination of the inert portion.
Disposal Routes for Surplus C&D Materials in Construction Phase
10.63 To transport the spoil from the works areas to barging points (BP), a conveyor system is proposed for Nam Cheong Works Area. For other works areas, spoil generated will be transported to the respective BPs by trucks. As for Tai Kong Po Works Area, SSS/ERS and Pat Heung Works Area, alternative haul roads have been considered to lessen the off-site traffic impact. For the wet spoil generated, it is expected that approximately 250 trucks per day would be needed for the transportation of the materials generated from sites to the Tuen Mun Area 38/ Tseung Kwan O Area 137 Fill Bank.
10.64
Six barging points (BP) are
designated for the Project at
Table 10.6 Summary of the Disposal Routes of the Works Areas
|
Works Area |
Waste Types |
Disposal Routes |
|
Mai Po |
Ÿ
Excavated
Materials Ÿ
Materials
from demolition works |
For excavated
materials: Segregation from other C&D materials during
stockpiling and transportation to enhance the reusable volume. The surplus
rocks, after testing for suitability, granites could be reused as concrete
aggregate while the other would be delivered to Taishan/HZMB (1)
by barges. Soft inert materials would be delivered to Taishan/HZMB (1)
by barges. Wet spoil, after pre-treatment, would be delivered to Tuen Mun
Area 38/Tseung Kwan O Area 137 Fill Bank and Taishan(1). For materials from demolition works: Materials recovered should be recycled or reused
as far as practicable. The remaining broken concrete would be delivered to
Tseung Kwan O Area 137 for beneficial use while bitumen would be stockpiled
on-site as future backfilling materials |
|
Ngau Tam Mei |
||
|
Tai Kong Po |
||
|
Tse |
||
|
Pat Heung |
||
|
Shek Yam ( |
||
|
Kwai Chung ( |
||
|
|
||
|
|
||
|
Mong Kok West |
||
|
Shek Kong |
Ÿ Excavated Materials |
For excavated
materials: Segregation from other C&D materials during
stockpiling and transportation to enhance the reusable volume. The surplus
rocks, after testing for suitability, granites could be reused as concrete
aggregate while the other would be delivered to Taishan/HZMB(1) by
barges. Soft inert materials would be delivered to Taishan/HZMB(1)
by barges. Wet spoil, after pre-treatment, would be delivered to Tuen Mun
Area 38/Tseung Kwan O Area 137 Fill Bank and Taishan(1). |
|
Shing Mun |
||
|
|
Ÿ
Excavated
materials Ÿ
Materials
from site formation and demolition works |
For excavated
materials: Segregation from other C&D materials during stockpiling
and transportation to enhance the reusable volume. The surplus rocks, after
testing for suitability, granites could be reused as concrete aggregate while
the other would be delivered to Taishan/HZMB(1) by barges. Soft
inert materials would be delivered to Taishan/HZMB(1) by barges.
Wet spoil, after pre-treatment, would be delivered to Tuen Mun Area 38/Tseung
Kwan O Area 137 Fill Bank and Taishan(1). For materials from demolition works: Materials recovered should be recycled or reused as
far as practicable. The remaining broken concrete would be delivered to
Tseung Kwan O Area 137 for beneficial use while bitumen would be stockpiled
on-site as future backfilling materials. For materials from site formation: Materials would be disposed of at NENT landfill. |
Notes:
1.
The disposal of C&D
materials at Taishan is considered as the last resort after exhausting all the
reuse outlets of the C&D materials generated from the Project.
10.65 The maximum number of ramps used will be limited for different BPs, depending on the volume of materials generated and the condition of seafront. Different types would be disposed at each BPs. A summary of materials disposed of and ramps used in the BPs is provided in Table 10.7 below.
Table 10.7 Summary of
Materials Disposed of and Ramps
Used in the Works Areas
|
Barging Points |
Materials Disposed |
Total Number of Ramps |
Serving Works Area |
|
|
Ÿ
Fill Ÿ
Rock Ÿ
Sediments |
5 |
WKT |
|
|
Ÿ
Fill Ÿ
Rock Ÿ
Sediments |
1 |
WKT |
|
2 |
Mong Kok West |
||
|
Rambler Channel |
Ÿ
Fill Ÿ
Sediments |
1 |
Kwai Chung |
|
1 |
Shek Yam Shing Mun |
||
|
Tsing Chau Tsai |
Ÿ
Rock |
2 |
Pak Heung Shek Yam |
|
Siu Lam |
Ÿ
Fill Ÿ
Sediments |
3 |
SSS/ERS |
|
Pillar Point |
Ÿ
Fill |
1 |
Tse Pat Heung |
|
Lung Kwu Sheung Tan |
Ÿ
Fill Ÿ
Rock |
1 |
Ngau Tam Mei Tai Kong Po |
|
1 |
Mai Po |
10.66 The surplus excavated materials would be transported by barges to Taishan. A summary of the estimated average and maximum barge loading of spoil removal for the Project and the proposed frequency of barge movements and the transporting routes, are shown Table 10.8.
Table 10.8 Summary of
Handling Rate and Frequency of Barge Movements
|
Barging Point |
Period |
Handling
Rate |
Barge Movements |
|
|
Around early 2010 to late 2013 |
Max. 19,000 ton/day |
About 10-13 barges per day travelling to Taishan/Public Fill/Reuse
Outlets |
|
|
Around mid 2010 to late 2013 |
Max. 13,500 ton/day |
About 7 barges per day travelling to Taishan/Public
Fill/Reuse Outlets |
|
Rambler Channel |
Around late 2010 to mid 2012 |
Max. 11,100 ton/day |
About 6 barges per day travelling to Taishan/Public
Fill/Reuse Outlets |
|
Tsing Chau Tsai |
Around late 2010 to early 2014 |
Max. 9,000 ton/day |
About 5 barges per day travelling to Taishan/Public
Fill/Reuse Outlets |
|
Siu Lam |
Around late 2010 to late 2013 |
Max. 3,000 ton/day |
About 2 barges per day travelling to Taishan/Public Fill/Reuse
Outlets |
|
Pillar Point |
Around early 2010 to mid 2011 |
Max. 3,000 ton/day |
About 2 barges per day travelling to Taishan/Public
Fill/Reuse Outlets |
|
Lung Kwu Sheung Tan |
Around late 2010 to late
2013 |
Max. 3,000 ton/day |
About 2 barges per day travelling to Taishan/Public
Fill/Reuse Outlets |
Notes:
1.
The disposal of C&D
materials at Taishan is the last resort after exhausting al the reuse outlets
of the C&D materials generated from the Project.
Imported
Fill Materials
10.67 It is anticipated that the filling materials would be stockpiled on-site, whenever possible and suitable, which could supply the required volume. Hence, no filling material is required for the Project.
Sediments
10.68 As stated in Table 10.1, sediments would be encountered at:
§
Cut-and-cover
tunnel alignment section from Chainage 140+380 to 140+900 and works areas for
Hoi Ting Road Construction Shaft,
§
Cut-and-cover
works areas for
§
Cut-and-cover
works area for Mei Lai Road Construction Shaft;
§
Stream
in Shek Kong and cut-and-cover works area for Tai Kong Po Emergency Access
Point;
§
Cut-and-cover
works area for
§
Dredging
area in Lung Kwu Sheung Tan.
10.69 In order to assess the sediment quality, a Sediment Sampling and Testing Plan (SSTP) was prepared, making reference to the guidelines in PNAP 252, to present a sampling and testing proposal as part of this EIA Study. The SSTP (Appendix 10.4) was submitted to EPD for agreement on the scope of works and testing requirements as required in Study Brief No. ESB-197/2008 Clause 3.4.5.2 and agreed by EPD on 19 May 2009. In view of prolonged application procedure for the excavation permits for sediment sampling and the tight programme of the Project, the site investigation (SI) works to determine the contamination level has been commenced from May 2008. The investigation was undertaken by Geotechnics & Concrete Engineering (HK) Ltd. (GCE). This comprises of 45 sampling locations at abovementioned works areas as shown in the SSTP. Samples were collected either by grab sampler, vibrocore or drillhole for Tier II chemical testing. The proposed sampling locations and corresponding methods can be referred to the SSTP in Appendix 10.4.
10.70 Each sample recovered from the SI was tested in the HOKLAS accredited laboratory for the following parameters as listed in PNAP 252:
(i) Metal and metalloid concentrations including chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), cadmium (Cd), nickel (Ni), zinc (Zn), silver (Ag) and arsenic (As);
(ii) Concentrations of organic compounds including total polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs); and
(iii) Concentration of Organometallics (TBT) in interstitial water.
10.71 After the chemical testing, the laboratory results were compared with the sediment quality criteria listed in Appendix A in PNAP 252 to categorise the sediments. If the result indicated that the sediment was a Category M sediment, Tier III biological screening was then carried out to determine the appropriate disposal methods in accordance with the requirements of PNAP 252:
(i) a 10-day burrowing amphipod toxicity test;
(ii) a 20-day burrowing polychaete toxicity test; and
(iii) a 48-96 hour larvae (bivalve or echinoderm) toxicity test.
10.73 The species used for each type of biological test and the test conditions are listed in Appendix B in PNAP 252. Sediment samples, which require biological screening, were also characterised by the testing laboratory for ancillary testing parameters such as porewater salinity, ammonia, TOC, grain size and moisture content. This provides necessary information on the general characteristics of the sediment.
Results of Chemical and
Biological Screening
10.75 A total of 53 samples had been collected from 22 sampling locations and tested while no sediment was encountered in 13 sampling locations. As the proposed dredging area in Lung Kwu Sheung Tan has been revised after the submission of SSTP, only two out of twelve proposed sampling locations (i.e. 2108/XRL/EDH-50 and 2108/XRL/EDH-51) were fallen within the new dredging area. A summary of the chemical screening results is presented in Table 10.9.
Table 10.9 Summary of Chemical Screening Results
|
Location |
Category |
No. of Samples |
Remarks |
|
Cut-and-cover
tunnel alignment section from Chainage 140+380 to 140+900 and works areas for
Hoi Ting Road Construction Shaft, |
L |
19 |
-- |
|
M |
3 |
Exceedance
of LCEL in heavy metals and PAHs |
|
|
H |
14 |
Exceedance
of UCEL in heavy metals and PAHs, 10 times exceedance of LCEL found in one
sample |
|
|
Cut-and-Cover
Works Areas for |
L |
4 |
-- |
|
H |
1 |
Exceedance
of UCEL in Zinc |
|
|
Cut-and-Cover
Works Area for |
** |
** |
** |
|
Stream
in Shek Kong and Cut-and-Cover Works Area for Tai Kong Po Emergency Access
Point |
L |
1 |
-- |
|
M |
3 |
Exceedance
of LCEL in heavy metals |
|
|
H |
3 |
Exceedance
of UCEL in heavy metals |
|
|
Cut-and-Cover
Works Area for |
H |
1 |
Exceedance
of UCEL in Arsenic |
|
Dredging
Area in Lung Kwu Sheung Tan |
L |
1 |
-- |
|
M |
3 |
Exceedance
of LCEL in heavy metals |
Notes:
** Drill log
indicated no sediment.
10.76 Tier III biological screening was also conducted for the Category M sediment samples and Category H sediment samples which exceed 10 times of LCEL as described in Section 10.72. As most of the samples requiring biological screening were distributed discretely, the biological screening was conducted on individual samples. The detailed results of the chemical and biological screening are presented in Appendix 10.5.
10.77 Based on the chemical and biological screening results, the disposal options for the identified contaminated sediment were determined in accordance with Appendix C of PNAP 252. As all the Category M samples failed the biological screening, together with the Category H samples (which do not exceed 10 times of LCEL), these sediments should be disposed at Type 2 confined marine disposal site. For Category H sample which exceeded 10 times of LCEL and failed the biological screening, these sediments are subject for Type 3 special treatment/ disposal. The rest of sediment (Category L) should be disposed at Type 1 open sea disposal site.
Estimated Quantities of
Sediment
10.78 Based on the construction profiles, depths and qualities of sediment, the quantities of sediment of different disposal options were estimated in different sections of the proposed tunnel, works areas and dredging areas. The estimation takes into account the corresponding depths of sediment from the geological logging information and the surface areas for proposed excavation/ dredging.
Tunnel
Alignment Section from Chainage 140+380 to 140+900 and Cut-and-Cover Works
Areas for
10.79
The construction of alignment
from Chainage approx. 140+380 to 140+900, Hoi Ting Road Construction Shaft,
Table 10.10 Estimated
Quantity of Different Types of Sediment to be Excavated and Handled in Tunnel
Alignment Section from Chainage 140+380 to 140+900 and Cut-and-Cover Works
Areas for Hoi Ting Road Construction Shaft, Mong Kok West Ventilation Building
and West Kowloon Terminus
|
Disposal
Options |
Estimated
Volume (X 1000 m3) |
% |
|
Type 1 |
99.1 |
41.6% |
|
Type 2 Confined Marine Disposal |
136.8 |
57.4% |
|
Type 3 Special Treatment/ Disposal |
2.6 |
1.0% |
|
Sub-Total |
238.5 |
100% |
Cut-and-Cover
Works Areas for
10.80
Open-cut excavation would be employed for the proposed C & C
works areas for
Table 10.11 Estimated
Quantity of Different Types of Sediment to be Excavated and Handled in
Cut-and-Cover Works Areas for
|
Disposal
Options |
Estimated
Volume (X 1000 m3) |
% |
|
Type 1 |
17.6 |
76.9% |
|
Type 2 Confined Marine Disposal |
5.3 |
23.1% |
|
Type 3 Special Treatment/ Disposal |
0 |
0% |
|
Sub-Total |
22.9 |
100% |
Cut-and-Cover
Works Area for
10.81 No sediment was found in sampling location 2108/XRL/D308. Therefore, sediment is unlikely to be excavated out during the open-cut excavation at the proposed C & C works area for Mei Lai Road Construction Shaft.
Stream
in Shek Kong and Cut-and-Cover Work Area for Tai Kong Po Emergency Access Point
10.82 The river training works in Shek Kong would involve excavation of 1 m down from the existing stream bed levels. Open-cut excavation would also be employed for the proposed C & C works area for Tai Kong Po Emergency Access Point to a depth of -22 mPD. Based on the drill log, no sediment was found in sampling location 2108/XRL/D434, thus sediment is unlikely to be encountered in the proposed C & C works area for Tai Kong Po Emergency Access Point. The quantities of sediment in Stream in Shek Kong are estimated by multiplying the surface area of the stream by the depth of excavation. The estimated quantities of sediment to be excavated out are summarised in Table 10.12.
Table 10.12 Estimated
Quantity of Different Types of Sediment to be Excavated and Handled at Stream
in Shek Kong and Cut-and-Cover Work Area for Tai Kong Po Emergency Access Point
|
Disposal
Options |
Estimated
Volume (X 1000 m3) |
% |
|
Type 1 |
4.1 |
14.4% |
|
Type 2 Confined Marine Disposal |
24.3 |
85.6% |
|
Type 3 Special Treatment/ Disposal |
0 |
0% |
|
Sub-Total |
28.4 |
100% |
Cut-and-Cover
Works Area for
10.83
Open-cut excavation would be
employed for the proposed C & C works area for
Table 10.13 Estimated
Quantity of Different Types of Sediment to be Excavated and Handled in
Cut-and-Cover Works Area for
|
Disposal
Options |
Estimated
Volume (X 1000 m3) |
% |
|
Type 1 |
0 |
0% |
|
Type 2 Confined Marine Disposal |
5.4 |
100% |
|
Type 3 Special Treatment/ Disposal |
0 |
0% |
|
Sub-Total |
5.4 |
100% |
Dredging
Area in Lung Kwu Sheung Tan
10.84 The seabed in Lung Kwu Sheung Tan would be dredged to 2 m deep from the existing seabed level with estimated area of 6,500 m2 for barges at approach channel and berthing area. The quantities of sediment are then estimated by multiplying the surface area required dredging by the depth of dredging. The estimated quantities of sediment to be dredged out are summarised in Table 10.14.
Table 10.14 Estimated
Quantity of Different Types of Sediment to be Dredged and Handled at Dredging
Area in Lung Kwu Sheung Tan
|
Disposal
Options |
Estimated
Volume (X 1000 m3) |
% |
|
Type 1 |
0 |
0% |
|
Type 2 Confined Marine Disposal |
13.0 |
100% |
|
Type 3 Special Treatment/ Disposal |
0 |
0% |
|
Sub-Total |
13.0 |
100% |
10.85 Current total estimation of the volume of sediments generated is approximately 308,200 m3. The estimated volume of contaminated sediments (Category M which failed the biological screening and H which were <10 x LCEL) requiring Type 2 confined marine disposal is approximately 184,800 m3, and the estimated volume of Category L sediment suitable for Type 1 open sea disposal is approximately 120,800 m3. The volume of Category H (>10 x LCEL) sediment requiring Type 3 special treatment/ disposal is estimated to be approximately 2,600 m3.
10.86 To minimise any potential adverse impacts arisings from the dredged/ excavated sediment, the sediment should be dredged/ excavated, transported and disposed of in a manner that would minimise the loss of contaminants either into air and surrounding water bodies, or by resuspension. Mitigation measures to minimise potential environmental impacts are recommended in Section” Mitigation Measures for Construction Phase”.
Chemical Waste
10.87 The maintenance and servicing of construction plant and equipment and the maintenance of vehicles involve the use of a variety of chemicals and generate chemical wastes. The possible chemical waste that would be generated during the course of construction works includes
§
Oil
and grease associated with plant and TBM maintenance;
§
Hydraulic
fluid from plant and TBM machinery;
§
Scrap
batteries from vehicle maintenance;
§
Used
paint, cleaners, solvents used in maintaining mechanical equipments; and
§
Used
solvents used in fixing tunnel segment gaskets.
10.88 It is difficult to quantify the amount of chemical waste that would arise from the construction activities since it would depend on the Contractor’s on-site maintenance requirements and the amount of plant utilised. However, it is anticipated that the quantity of chemical waste, such as lubricating oil and solvent produced from plant maintenance, would be small and in the order of a few hundred litres per month per construction site. The amount of chemical waste to be generated would be quantified in the WMP to be prepared by the Contractors.
10.89 As stipulated in the Waste Disposal (Chemical Waste) (General) Regulations, chemical wastes arisen during the construction phase may pose environmental, health and safety hazards if not stored and disposed of appropriately. These hazards may include:
§
Toxic
effects to workers;
§
Adverse
impacts on water quality from spills; and
§
Fire
hazard.
10.90 Chemical waste will be collected by licensed collectors and disposed of at the Chemical Waste Treatment Centre (CWTC) at Tsing Yi. Wherever possible opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for chemical wastes are detailed in Sections 10.136 - 10.139.
10.91 The handling, storage and disposal of chemical waste would follow the Code of Practice on Packaging, Labelling and Storage of Chemical Wastes published by EPD and the anticipated adverse environmental impacts would be negligible.
General Refuse
10.92 During the construction period, the workforce would generate refuse comprising food scraps, waste paper, empty containers, etc. Accidental or intentional release of these refuse to the surrounding environment is not permitted and may cause negative environmental impacts. Storage of general refuse at site will generate adverse environmental impacts like water contamination, odour nuisance and visual impact if they are not managed in a proper manner. The site may also attract vermin and pests if the waste containers are not cleaned or maintained properly and frequently.
10.93
The maximum number of
construction workers to be employed on the Project is estimated to be about 5,500
workers. Based on a generation rate of
10.95 With proper implementation of waste management practices, it is anticipated that the secondary environmental impacts from collection and handling of general refuse would be minimal.
Sewage
10.96 Sewage will arise from amenity facilities used by the construction workers and site office’s sanitary facilities. Night soil from chemical toilets will also be generated. The sludge generated needs to be properly managed to minimise the adverse impact of odour and potential health risks to the workers by attracting pests and other disease vectors.
10.97 It is anticipated that no adverse environmental impact would arise if the chemical toilets are properly maintained and licensed collectors are employed for the collection and disposal of sewage on a regular basis.
Evaluation of Environmental Impacts for
Operation Phase
§
Chemical
waste;
§
General
refuse; and
§
Industrial waste.
Chemical Waste
10.99
Chemical wastes such as paints,
lubricants and used batteries may be generated during maintenance activities in
SSS, WKT and at the ventilation buildings. This waste may pose environmental, health and
safety hazards. Measures as stipulated
in the Waste Disposal (Chemical Waste)
(general) Regulation and the Code of
Practice on the Packaging, Labelling and Storage of Chemical Wastes would
be strictly followed for the handling and disposal of chemical waste..
10.100
Should any chemical waste be
generated, the operator must register with EPD as a chemical waste
producer. The chemical waste would be
readily accepted for disposal at the CWTC at Tsing Yi. This chemical waste should be collected
periodically in drum-type containers by licensed chemical waste
collectors. With proper storage,
handling and disposal of this waste, no adverse environmental impact is
anticipated.
General Refuse
10.101 During the operation phase, general refuse would be generated by staff and passengers of XRL and any commercial operators in WKT. This waste includes food waste, paper, wood, plastic, office waste etc. Plastics, papers and other recyclable wastes should be separated from general refuse and recycled as far as possible. The remaining refuse would be collected by licensed collectors and disposed of at landfills.
Industrial Waste
10.102 Maintenance activities would be conducted in WKT, SSS and ventilation buildings, which would generate industrial waste including scrap materials from rail and carriage maintenance, used fluorescent tubes, used welding rods, cleansing materials and discarded electronic equipment. Steel would be sorted out as far as possible before collection by licensed collectors.
10.103
Table 10.15 provides a summary on the
recommended disposal methods of different wastes generated from the operation
phase of the Project.
Table 10.15 Summary of Waste Disposal for Operation
Phase
|
Type of
Waste |
Proposed
Disposal Methods |
|
Chemical Waste |
Recycle by licensed facility or disposal
at CWTC |
|
General Refuse |
Reuse, recycle as much
as possible before disposal at landfill |
|
Industrial
Waste |
Sorted
and recycled before collection by licensed collector |
10.104 The anticipated potential environmental impacts arisen from the handling, storage and disposal of waste in operation phase would be insignificant provided that the mitigation measures stated in Section 10.145 – 10.150 are strictly followed.
Mitigation Measures for Construction Phase
Waste Management Hierarchy
§
Avoidance and reduction of waste generation;
§
Reuse of materials as far as practicable;
§
Recovery and recycling of residual materials where possible;
and
§
Treatment and disposal according to relevant laws,
guidelines and good practices.
10.106 Based on the waste management hierarchy, waste reduction measures are recommended as follow to reduce impacts and costs arisen from the Project. Recommendations of good site practices and waste reduction measures would be stated in order to achieve avoidance and minimisation of waste generation in the hierarchy. Waste Management Plan and trip- ticket system are recommended for monitoring management of waste. Specific measures targeting the mitigation of impacts in works areas and the transportation of spoil off-site would be provided to minimise the potential impacts to the surrounding environment together with recommendations on sediments management.
Good Site Practices
and Waste Reduction Measures
10.107 Adverse impacts related to waste management are not expected to arise, provided that good site practices are strictly followed. Recommendations for good site practices during the construction phase include:
§
Prepare
a Waste Management Plan approved by the Engineer/Supervising Officer of the
Project based on current practices on construction sites;
§
Training of site personnel in, site cleanliness, proper
waste management and chemical handling procedures;
§
Provision
of sufficient waste disposal points and regular collection of waste;
§
Appropriate
measures to minimise windblown litter and dust during transportation of waste
by either covering trucks or by transporting wastes in enclosed containers;
§
Regular cleaning and maintenance programme for drainage
systems, sumps and oil interceptors; and
§
Separation of chemical wastes for special handling and
appropriate treatment.
10.108 Good management and control can prevent the generation of a significant amount of waste. Waste reduction is best achieved at the planning and design stage, as well as by ensuring the implementation of good site practices. Recommendations to achieve waste reduction include:
§
Sorting
of demolition debris and excavated materials from demolition works to recover
reusable/ recyclable portions (i.e. soil, broken concrete, metal etc.);
§
Segregation
and storage of different types of waste in different containers, skips or
stockpiles to enhance reuse or recycling of materials and their proper
disposal;
§
Encourage
collection of aluminium cans by providing separate labelled bins to enable this
waste to be segregated from other general refuse generated by the workforce;
§
Proper
storage and site practices to minimise the potential for damage or
contamination of construction materials;
§
Plan
and stock construction materials carefully to minimise amount of waste
generated and avoid unnecessary generation of waste; and
§
Training
should be provided to workers about the concepts of site cleanliness and
appropriate waste management procedures, including waste reduction, reuse and
recycle.
10.109 The Contractor shall prepare and implement a WMP as a part of Environmental Management Plan (EMP), in accordance with ETWB TCW No. 19/2005 which describes the arrangements for avoidance, reuse, recovery, recycling, storage, collection, treatment and disposal of different categories of waste to be generated from the construction activities. Such a management plan should incorporate site specific factors, such as the designation of areas for segregation and temporary storage of reusable and recyclable materials. The WMP should be submitted to the Engineer for approval. The Contractor should implement the waste management practices in the WMP throughout the construction stage of the Project. The WMP should be reviewed regularly and updated by the Contractor, preferably in a monthly basis, to incorporate any revisions, measures or suggestions discovered during the construction periods for implementation.
10.110 In addition to the above good site practices and waste reduction measures, specific measures concerning the reduction of waste generation and maximisation of reuse of C&D materials have been discussed in Section 10.34 – 10.38 and Section 10.39 – 10.52 respectively.
10.111 Over 70% of the total volume of sediments is generated from cut-and-cover works area for West Kowloon Terminus. The current scheme for WKT is regarded as the best option to fulfil all functional requirements such as usage, floor area, location, connectivity and construction management. However, in order to minimise the volume of sediment generated from the Project, the following measures have been explored and implemented:
§
The
cut-and-cover works areas including WKT, ERS, launching shafts, ventilation
shafts, etc. required by the Project have been reviewed and optimised to the
minimum necessary to ensure the viable construction as well as safe operation
of an express railway line;
§
A
400m long tunnel section along
§
Innovative
pile removal method is to be employed to extract piles of existing property
foundations at Nam Cheong Station instead of using C & C method as proposed
in PPFS;
§
Smaller
barges will be employed for carrying spoil from Lung Kwu Sheung Tan barging point,
sediment to be dredged to maintain a navigation channel is substantially
reduced.
Storage, Collection and Transportation of Waste
§
Waste,
such as soil, should be handled and stored well to ensure secure containment,
thus minimising the potential of pollution;
§
Maintain
and clean storage areas routinely;
§
Stockpiling
area should be provided with covers and water spraying system to prevent
materials from wind-blown or being washed away; and
§
Different
locations should be designated to stockpile each material to enhance reuse.
10.113 Waste haulier with appropriate permits should be employed by the Contractor for the collection and transportation of waste from works areas to respective disposal outlets. The following suggestions should be enforced to minimise the potential adverse impacts:
§
Remove
waste in timely manner;
§
Waste
collectors should only collect wastes prescribed by their permits;
§
Impacts
during transportation, such as dust and odour, should be mitigated by the use
of covered trucks or in enclosed containers;
§
Obtain
relevant waste disposal permits from the appropriate authorities, in accordance
with the Waste Disposal Ordinance (Cap.
354), Waste Disposal (Charges for
Disposal of Construction Waste) Regulation (Cap. 345) and the Land (Miscellaneous Provisions) Ordinance
(Cap. 28);
§
Disposal
of waste should be done at licensed waste disposal facilities;
§
Maintain
records of quantities of waste generated, recycled and disposed; and
§
Present
valid ‘chit’ with the ‘Disposal Delivery Form’ to the authority for disposal at
landfills.
10.114 Implementation of trip ticket system with reference to ETWB TC(W) No.31/2004, Trip Ticket System for Disposal of Construction & Demolition Materials, to monitor disposal of waste and to control fly-tipping at PFRFs or landfills. A recording system for the amount of waste generated, recycled and disposed (including disposal sites) should be proposed.
10.115 In order to fully implement the trip-ticket system, it is recommended that warning signs should be put up at the temporary and permanent accesses of vehicle to remind the drivers of dump truck of the proper designated disposal outlet and the penalties of offence. Further, close-circuited television (CCTV) should also be installed at the access points to monitor and prevent illegal dumping, especially during night time. To prevent illegal entrance of the dumping sites at night and during public holidays, fences should be installed.
10.116 In addition to the above measures, other specific mitigation measures on handling the C&D materials, sediments and materials generated from site formation and demolition work are recommended as follow.
C&D Materials
10.117 As the end use of spoil may be different, separation of material at storage and transportation should be promoted. It is thus recommended that:
§
Several
ramps should be used for transportation of different materials as far as
practicable (at SSS/ERS site, both soft and hard materials could be generated
with the provision of three ramps, each of them can be used for single material
for primary separation). Each ramp
should be used for transportation of a single material only;
§
If
a conveyor system is used as in Nam Cheong, materials should be transported
separately on the belts, it is therefore proposed that more than one conveyor
belt should be installed if possible. If
more than one material is needed to be transported on a single belt, each
material should be stockpiled separately once they are removed from the
excavation face to the ground and the belt should operate at different times
with different materials. Enclosure
should also be provided for the conveyor belt, as far as
practicable to minimise the
generation of dust which would affect the surrounding environment; and
§
Different
locations should be designated for each material during stockpiling. Stockpiling may be needed when the conveyor
system is under constraint or when the spoil could not be transported away from
works area immediately after excavation.
Cover should be provided to dusty stockpiles to avoid the materials from
being wind-blown or flushed away by water.
It is expected that water spraying system should also be equipped to
moisten the materials.
10.118 The Contractor may decide to stockpile suitable materials on site for reuse, if provision of suitable area is possible, or off-site disposal afterwards.
10.120 Wheelwash facilities have to be provided before the trucks leave the works area. This can reduce the introduction of dust to the public road network.
10.121 For the disposal of non-inert C&D materials at NENT landfill, the Contractor should ensure the on-site separation from inert portion as mentioned in Section 10.54 - 10.56. The waste delivered to landfill should not contain any free water or have water content more than 70% by weight. Concerning the requirement on the truck load of waste to landfill, the haulier must ensure suitable amount of waste would be loaded on different types of trucks used. A one-week notice should be given to EPD with information on Contractor’s name and respective contact details.
Sediments
10.122 With implementation of the measures concerning the reduction of sediment generated in Section 10.111, the estimated total volume of sediments generated is about 308,200 m3. Based on the chemical and biological screening results and guidelines in PNAP 252, the estimated volume of sediments suitable for Type 1 open sea disposal is approximately 120,800m3, and the estimated volume of sediments requiring Type 2 confined marine disposal is approximately 184,800m3. The volume of sediments requiring Type 3 special treatment/ disposal is estimated to be approximately 2,600m3. MFC has advised that subject to approval of the Sediment Quality Report and consent to dump land-based material excavated from a site to be dumped at sea given by EPD, MFC would have no probelm to allocated not more than 0.253 Mm3 and 0.468 Mm3 bulk volume for Type 1 open sea disposal and Type 2 confined marine disposal respectively for the Project.
10.123 This will generally follow the PNAP 252 in handling of dredged/excavated sediment. The dredged / excavated sediments would be loaded onto barges and transported to existing designated disposal sites allocated by the MFC according to their levels of contamination, as presented below:
§
For
Type 1 disposal, the sediments will be excavated/dredged and transport to
designated CEDD Facilities, typically at South Cheung Chau and/or East of
Ninepin.
§
For
Type 2 disposal, the sediments will be dredged/excavated and transport to
designated CEDD Facilities, typically at East Sha Chau for confined marine
disposal.
§
For
Type 3 disposal, DEP's agreement on the most appropriate treatment and disposal
arrangement will be sought .
10.124
A possible arrangement for Type
3 disposal is by geosynthetic containment. A geosynthetic containment method is
a method whereby the sediments are sealed in geosynthetic containers and, at
the disposal site, the containers would be dropped into the designated
contaminated mud pit where they would be covered by further mud disposal and
later by the mud pit capping, thereby meeting the requirements for fully
confined mud disposal. The technology is readily available for the manufacture
of the geosynthetic containers to the project-specific requirements. Similar
disposal methods have been used for projects in Europe, the
10.125 Moreover, the geosynthetic containment is proposed for Type 3 diposal in local project “Wan Chai Development Phase II and Central-Wan Chai Bypass”[3]. Field trials were also undertaken during WD II Design and Construction (D&C) Consultancy (Agreement No. CE54/2001 (CE)) using uncontaminated mud to demonstrate the feasibility of the geosynthetic containment. Report on the field trials concluded that disposal by sealing the sediments in geosynthetic containers and dropping these containers into the contaminated mud pits at East Sha Chau has been shown to be a successful and viable disposal method. The use of a geosynthetic container system for special disposal was considered to be an effective system with negligible loss of contaminants to the marine environment during disposal. However, field trials are still recommended to be undertaken during the detailed design stage to establish the optimum handling method for this approach. The details of the disposal methodology could therefore be confirmed during the detailed design stage, prior to construction.
10.126 The basic requirements and procedures for dredged / excavated sediment disposal specified under PNAP 252 shall be followed. MFC is responsible for the provision and management of disposal capacity and facilities for the dredged/ excavated sediment, while the permit of marine dumping is required under the Dumping at Sea Ordinance and is the responsibility of the DEP.
10.127 The Project Proponent will agree in advance with MFC of CEDD on the site allocation by submitting a Construction & Demolition Material Management Plan. The final disposal sites and arrangement will be determined by the MFC and a dumping permit will be obtained from the DEP prior to the commencement of the dredging and excavation works.
10.128 The contractor for the dredging/ excavation works shall apply for the site allocations of marine sediment disposal based on the prior agreement with MFC/CEDD. The contractor shall apply for all necessary permits from relevant authorities for the disposal of dredged / excavated sediment.
10.129 If temporary stockpiling of sediments is necessary, the sediment should be covered by tarpaulin and earth bunds or sand bag barriers should be provided on site to prevent leachate from entering the drains and surrounding water bodies. The stockpiling areas should be completely paved or covered by lining avoiding contaminating the soil or groundwater underneath.
10.130 The dredged / excavated sediment should be transported by covering trucks to designated barging points. The barge transporting the sediments to the designated disposal sites should be equipped with tight fitting seals to prevent leakage. Besides, the barge should not be filled to a level that would cause overflow of materials or laden water during loading or transportation.
10.131 Loading of the dredged / excavated sediment to the barge should be controlled to avoid splashing and overflowing of the sediment slurry to the surrounding water. Storage of the dredged / excavated sediment at the site should be avoided.
10.132 In order to minimise the potential odour emissions during the dredging / excavation operation and transportation of the sediment, the dredged / excavated sediment placed on barges should be properly covered as far as practicable. Requirement of the Air Pollution Ordinance (Construction Dust) Regulation, where relevant, shall be adhered to during the construction phase of the Project.
10.133 The potential water quality impacts due to the dredging and disposal of these sediments are assessed and presented in Section 11, Water Quality Impact Assessment. The assessment concludes that the dredging works can meet the relevant assessment criteria and provides the recommended mitigation measures.
10.134 In order to minimise the exposure to the contaminated sediments, the workers should wear protective gloves when carrying out the dredging / excavation works. Adequate washing and cleaning facilities should be provided on site.
Chemical Wastes
§
Be compatible with the chemical
wastes being stored, maintained in good condition and securely sealed;
§
Have a capacity of less than 450
litres unless the specifications have been approved by EPD; and
§
Display a label in English and
Chinese in accordance with instructions prescribed in Schedule 2 of the Waste
Disposal (Chemical Waste)(General) Regulation.
10.137 The Chemical storage area should:
§
Be clearly labelled to indicate corresponding
chemical characteristics of the chemical waste and used for
storage of chemical waste only;
§
Be enclosed on at least 3 sides;
§
Have an impermeable floor and bunding,
of capacity to accommodate 110% of the volume of the largest container or 20%
by volume of the chemical waste stored in that area, whichever is the greatest;
§
Have adequate ventilation;
§
Be covered to prevent rainfall from
entering; and
§
Be properly arranged so that
incompatible materials are adequately separated.
10.138 Lubricants, waste oils and other chemical wastes would be generated during the maintenance of vehicles and mechanical equipments. Used lubricants should be collected and stored in individual containers which are fully labelled in English and Chinese and stored in a designated secure place. These chemical wastes should be sent to oil recycling companies, if possible, and the empty oil drums should be collected by appropriate companies for reuse or refill. They should not be allowed to discharge into water courses, either by direct discharge, or as contaminants carried in surface water runoff from the construction site.
General Refuse
10.140 General refuse should be stored in enclosed bins or compaction units separate from C&D materials and chemical waste. A reputable waste collector should be employed by the contractor to remove general refuse from the site, separately from C&D materials and chemical wastes. Preferably, an enclosed and covered area should be provided to reduce the occurrence of wind blown light material.
10.141 The recyclable component of general refuse, such as aluminium cans, paper and cleansed plastic containers should be separated from other waste. Provision and collection of recycling bins for different types of recyclable waste should be set up by the Contractor. The Contractor should also be responsible for arranging recycling companies to collect these materials.
10.142 The Contractor should carry out an education programme or training for workers in avoiding, reducing, reusing and recycling of materials generation. Posters and leaflets advising on the use of the bins should also be provided in the sites as reminders.
Sewage
10.143 As the workers and staff are likely to be scattered along the proposed alignment and works areas, it the most effective to provide adequate portable toilets to ensure the sewage from them is properly collected. The WMP should also document the locations and number of portable toilets depending on the land availability, site conditions and activities.
Table
10.16 Summary of Waste
Generation and Recommended Disposal Methods for Construction and Demolition Works
|
Waste
Materials Type |
Generation
from work items |
Materials
Generated |
Total
approx. Quantity Generated |
Approx.
Disposal Quantity |
Handling
methods/Reuse |
Destinations |
|
|
C&D
Materials |
Excavated Materials |
Construction of tunnel, adits,
ventilation buildings and the terminus |
Rocks – grade I/II granites |
1,272,400 m3 (Table 10.2) |
Ÿ If reuse outlets
available, 1,129,400 m3 (4) material require
disposal. |
Ÿ Segregation from other
C&D materials during stockpiling and transportation Ÿ Stockpile area should be
well managed with covers and water spraying system Ÿ Transportation off-site
by covered trucks or conveyor system (Nam Cheong) to respective BPs
identified in Section 10.63 |
Ÿ Taishan, Mainland(3) Ÿ Man-made
|
|
Rock other than grade I/II granites (1) |
1,504,100 m3 (Table 10.2) |
Ÿ If reuse outlets
exhausted, 2,776,500 m3 material require disposal. (Appendix
10.2) |
Ÿ Taishan, Mainland(3) Ÿ Man-made
Ÿ Concrete
batching plant (grade III/IV granites only) |
||||
|
|
|
|
Soft inert materials |
5,378,800
m3 (Table 10.2) |
Ÿ If reuse outlets
available, 3,143,300 m3 material require disposal. |
Ÿ 619,900 m3
would be reused as backfilling materials as identified in Section 10.28 |
Ÿ WKT Ÿ Ÿ Mai Po Works Area |
|
Ÿ If reuse outlets
exhausted, 4,758,900 m3 material require disposal. (Appendix
10.2) |
Ÿ Segregation from other
C&D materials during stockpiling and transportation Ÿ Stockpile area should be
well managed with covers and water spraying system Ÿ Transportation off-site
by covered trucks or conveyor system (Nam Cheong) to respective BPs
identified in Section 10.63 |
Ÿ Taishan, Mainland(3) Ÿ Man-made
|
|||||
|
Soft Materials – Wet Spoil |
1,511,000
m3 (Table 10.2) |
1,511,000 m3 (Appendix 10.2) |
Ÿ Wet spoil should be
treated before transportation to reduce water content. Ÿ Spoil from construction of
D-wall and bored piling should be treated with dry spoil while those from TBM
excavation should be treated with lime or cement in spoil mud pit |
Ÿ Tuen Mun Area 38 Fill
Bank/Tseung Kwan O 137 Fill Bank Ÿ Taishan, Mainland(3) |
|||
|
Materials from Demolition Works |
Demolition of existing structures |
Inert C&D materials – AHM - Broken Concrete |
74,000 m3 (Table 10.2) |
- |
Ÿ Reusable materials such
as metals and steel should be separated and recycle as far as practicable Ÿ Size larger than 250mm
should be crushed before further reuse on-site as sub-base or pipe bedding
materials, hard core, backfilling materials or concrete aggregates Ÿ Remainders, with size
smaller than 250mm, should be delivered to PFRFs for beneficial use in other
project (Section 10.58) |
Ÿ Reused on-site Ÿ Tseung Kwan O Area 137
Fill Bank |
|
|
Inert C&D materials – AHM - Bitumen |
15,600 m3 (Table 10.2) |
- |
Ÿ Stockpile area should be
provided on-site for on-site storage of the materials which could be reused
as backfilling materials in the future as stated in Section 10.58 |
Reuse on-site as backfilling
materials |
|||
|
Materials from Site Formation |
Site formation works |
Trees, timbers, plastics, papers etc. |
29,900 m3 (Table 10.2) |
29,900 m3 (Section 10.61) |
Ÿ Disposed off-site in designated government landfill |
NENT Landfill |
|
|
Sediment |
Construction of tunnel, ventilation
buildings, construction shafts and the terminus Dredging works in Lung Kwu Sheung
Tan and river training works at Shek Kong |
Category L Sediment |
Estimated
total of 120,800 m3 (Tables 10.10 to 10.14) |
Estimated
total of 120,800 m3 (Tables 10.10 to 10.14) |
Ÿ Type 1 – Open Sea
Disposal - gazetted marine disposal ground
allocated by MFC Ÿ Stockpile with tarpaulin
covers with earth bunds and sand bags barriers, if applicable |
South Cheung Chau/ East of Ninepin |
|
|
Category M Sediment failed the biological screening and Category H Sediment passed the
biological screening |
Estimated
total of 184,800 m3 (Tables 10.10 to 10.14) |
Estimated
total of 184,800 m3 (Tables 10.10 to 10.14) |
Ÿ Type 2 – Confined Marine Disposal - Disposal at existing
marine disposal facilities allocated by MFC Ÿ Stockpile with tarpaulin
covers with earth bunds and sand bags barriers, if applicable |
|
|||
|
Category H Sediment failed the biological screening |
Estimated
total of 2,600 m3 (Tables 10.10 to 10.14) |
Estimated
total of 2,600 m3 (Tables 10.10 to 10.14) |
Ÿ Type 3 – Special
Treatment/ Disposal - Disposal at existing marine disposal facilities
allocated by MFC with geosynthetic containment Ÿ Stockpile with tarpaulin
covers with earth bunds and sand bags barriers, if applicable |
|
|||
|
Chemical Waste |
Maintenance and Operation of
Equipments and Machineries |
Oils and grease hydraulic fluids,
paints, solvents, cleaners etc. |
Small – Few hundreds litres per
month per site (Section 10.88) |
Few hundreds litres per month per
site (Section 10.90) |
Ÿ Stored in compatible
containers in designated area on site Ÿ Collected and recycled
by licensed collectors |
Ÿ Chemical Waste Treatment
Centre at Tsing Yi |
|
|
General Refuse |
Resident Workers and staff |
Food waste, plastic, aluminium cans,
waste papers etc. |
3,575 kg/day (5,500 workers for
0.65 kg/day/person) (Section 10.93) |
3,575 kg/day (Section 10.94) |
Ÿ Provide on-site
collection points together with recycling bins Ÿ Collected by licensed
collectors |
Ÿ Landfills |
|
Note:
1.
Include grade III/IV
granites and volcanics
2.
Assume all sediment will be
accepted at CEDD Disposal Facilities.
3.
Disposal to Taishan is
considered as the last resort if all the possible reuse outlets of the C&D
materials are exhausted during construction stage.
4.
1,320,000m3 of
granites to be reused as concrete aggregate is not included in the calculation
of disposal quantity.
Mitigation Measures for Operation Phase
Chemical Waste
10.146 The requirements given in the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes would be followed in handling of chemical waste as in construction phase. A trip-ticket system would be adopted by the operator to monitor disposal of chemical waste.
10.147 Non-recyclable chemical waste should be disposed of at appropriate facility like CWTC by licensed collectors. Recyclable chemical waste should be collected and transported off-site by licensed collectors.
General Refuse
10.148 Recycling of waste paper, aluminium cans and plastic bottles should be encouraged, it is recommended to place clearly labelled recycling bins at designated locations which could be accessed conveniently. Other general refuse should be separated from chemical and industrial waste by providing separated bins for storage to maximise the recyclable volume.
10.149 A reputable licensed waste collector should be employed to remove general refuse from the WKT/SSS on a daily basis to minimise odour, pest and litter impacts.
Industrial Waste
Impacts Caused by Handling, Collection and
Disposal of Waste
10.151 The assessment should cover the following area: potential hazard, air and odour emission, noise and wastewater discharge. With the implementation of mitigation measures recommended in the Sections 10.105 – 10.144, impacts caused by handling, collection, transportation and disposal of waste regarding the above mentioned issue is expected to be minimal. The issues would be separately addressed in other relevant sections of this EIA report.
Evaluation of Residual Impacts
10.152 With the implementation of the recommended mitigation measures for the handling, transportation and disposal of the identified waste arisings, no residual impact is expected during both construction and operation phases.
Environmental
Monitoring and Audit Requirements
Construction Phase
10.153 During the construction period, it is the Contractor’s responsibility to ensure that all waste produced during the construction of the Project are handled, stored and disposed of in accordance with good waste management practices, relevant legislation and waste management guidelines.
10.154 Waste materials generated during construction activities, such as
C&D materials, are recommended to be audited at regular intervals to ensure
that proper storage, transportation and disposal practices are being
implemented. This would ensure the waste
generated would be properly disposed of.
The Contractor would be responsible for the implementation of any
mitigation measures to minimise waste or mitigate problems arisen from waste materials.
10.155 A WMP should be prepared in accordance to with ETWB TC(W) No.19/2005 and submitted to the Engineer for approval. The recommended mitigation measures should form the basis of the WMP. The monitoring and auditing requirement stated in ETWB TC(W) No.19/2005 should be followed with regard to the management of C&D materials.
Operation Phase
10.156 As it is not expected that large quantities of waste will be generated from the operation of the Project and no adverse environmental impacts will arise with the implementation of good waste management practices, waste monitoring and audit programme for the operation phase of the Project will not be required.
10.157 Waste types generated by the construction of this Project are likely to include C&D materials (from excavation of shafts and tunnels, demolitions of existing structures and site formation), sediment; chemical waste from maintenance of construction plant and equipment; general refuse and sewage from workforce. Provided that these wastes are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts are not expected during the construction phase.
10.158 Reduction measures have been recommended to minimise the amount of materials generated in the Project. It is anticipated that approximately 9,785,900 m3 of C&D materials would be generated in construction phase. These materials generated would be reused as far as practicable on-site and other possible reuse outlets as identified in the assessment before off-site disposal. An estimated 619,900 m3 of soft inert materials would be reused as backfilling materials and 89,600 m3 of AHM could be reused on-site as backfilling materials or for beneficial use in other projects.
10.159 Concerning the volume requiring disposal, opportunities in minimisation of generation and maximisation of reuse would be continuously investigated during the detailed design and construction phases in an attempt to further reduce the possible impacts from the generation. The estimated maximum quantity of material to be reused in HZMB and for concrete aggregates is approximately 3,262,600 m3, subject to further agreement and revision of programme. It is predicted that approximately 5,813,700 m3 would be disposed of to designated outlets if they are available during construction stage, however 9,076,300 m3 of materials would require disposal if no suitable outlets could receive the materials. Continuous liaison would therefore be conducted with relevant parties of other projects to maximize the reuse volume.
10.160 The total volume of dredged/ excavated sediment generated from the Project is estimated to be approximately 308,200 m3. Based on the results of the chemical and biological screening, approximately 120,800 m3 sediment is suitable for Type 1 – Open Sea Disposal at South Cheung Chau or East of Ninepin, 184,800 m3 sediment requires Type 2 – Confined Marine Disposal at East Sha Chau and 2,600 m3 sediment requires Type 3 – Special Treatment/Disposal in accordance with PNAP 252.
10.161 It is proposed that the excavated Type 3 sediments are sealed in geosynthetic containers and, at the disposal site, the containers would be dropped into the designated contaminated mud pit where they would be covered by further mud disposal and later by the mud pit capping, thereby meeting the requirements for fully confined mud disposal. Field trials are recommended to be undertaken during the detailed design stage to establish the optimum handling method. EPD’s agreement will be sought on the above arrangement. The final disposal sites and arrangement will be determined by the MFC and a dumping permit will be obtained from the DEP prior to the commencement of the dredging and excavation works.
10.162 A proposal for sampling and chemical testing of the sediment should be prepared and submitted to EPD and the results should be presented in a Sediment Quality Report (SQR) for EPD endorsement according to the Dumping at Sea Ordinance and PNAP 252 for allocation of sediment disposal site and application of marine dumping permit. The final disposal sites for the sediment will be determined by the MFC prior to the commencement of the dredging/excavation activities. With the implementation of the recommended mitigation measures detailed in Sections 10.122 - 10.135 in accordance with the requirements of PNAP 252, no adverse environment impacts would be expected.
10.163 The main waste types generated during the operation of the Project would be general refuse from the passengers, staff and any commercial operators at WKT, ventilation buildings and shafts, industrial waste from the maintenance activities and chemical waste from operational activities. The handling, collection, transportation and disposal practices of the identified waste generated should follow the current practices at other operating railway lines. It is anticipated that no adverse impacts would arise if the mitigation measures are strictly followed.
[1] EPD’s letter dated 19 May 2009 (Ref:
EP 195/01/24/1644/2009)
[2] (i) Young, H. M. et al. “The
migration of contaminants through geosynthetic fabric containers utilized in
dredging operation”. Engineering Geology, 53 (1999), 167-176;
(ii) Fleischer, P., Bowles, F.A.
“Turbidity currents generated by seafloor impact of geotextile fabric
containers”. Applied Ocean Research, 21 (1999), 215-217; and
(iii) Valent,
P. J. et al. “Engineering concepts for the placement of wastes on the abyssal
seafloor” Journal of Marine Systems, 14 (1998), 273-288.
[3] Environmental Impact Assessment Report for Wan Chai Development Phase II and Central-Wan Chai Bypass by CEDD in 2007.