12.2 Environmental Legislation and Standards
12.4 Construction Phase Waste Management Assessment
12.5 Operational Phase Waste Management Assessment
12.7 Waste Disposal Recommendations
12.9 Monitoring and Audit Requirements
12.1.1.1 This section identifies potential wastes that may arise from the construction and operation of the TM-CLKL project and assesses potential environmental impacts associated with their handling and disposal. Options of reuse, minimization, recycling, treatment, storage, collection, transport and disposal of such wastes have been examined. Where appropriate, procedures for waste reduction and management have been considered, with environmental control measures to avoid or minimise impacts recommended.
12.2 Environmental Legislation and Standards
12.2.1 Background
12.2.1.1 The following legislation is relevant to the handling, treatment and disposal of waste in HKSAR, and will be considered in assessing potential impacts and their avoidance or mitigation:
· Waste Disposal (Amendment) Ordinance (Cap 354);
· Dumping at Sea Ordinance (Cap 466);
· Land (Miscellaneous Provisions) Ordinance (Cap 28); and
· Public Health and Municipal Service Ordinance (Cap 132) – Public Cleansing and Prevention of Nuisances By-laws.
12.2.1.2 Under the Waste Disposal (Amendment) Ordinance, some of the regulations are relevant to this EIA, including:
· Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap 354); and
· Waste Disposal (Chemical Waste) (General) Regulation (Cap 354).
12.2.2 Waste Disposal (Amendment) Ordinance and the Waste Disposal (Charges for Disposal of Construction Waste) Regulation
12.2.2.1 The Waste Disposal (Amendment) Ordinance (WDO) prohibits unauthorised disposal of wastes. Schedule 5 of the Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Charging Regulation) also defines that the inert construction waste includes rock, rubble, boulder, earth, soil, sand, concrete, brick, tile, masonry or used bentonite.
12.2.2.2 Under the WDO and the charging regulation, wastes can only be disposed of at designated waste disposal facilities licensed by the EPD. For construction work with a value of more than HK$1 million, the main contractor is required to establish a billing account at the EPD before transporting the construction waste to the designated waste disposal facilities (for example, landfill and public fill). The vessels for delivering construction waste to the public fill reception facilities require prior approval from the Public Fill Committee (PFC). Any breach of these regulations may lead to a fine and/or imprisonment.
12.2.3 Waste Disposal (Chemical Waste) (General) Regulation
12.2.3.1 Chemical waste includes any scrap materials or unwanted substances specified under Schedule 1 of this Regulation if such a substance or chemical occurs in such a form, quantity or concentration that causes pollution or constitutes a danger to health or risk of pollution to the environment.
12.2.3.2 A person shall not produce, or cause to be produced, any chemical wastes unless he/she is registered with the EPD, otherwise, it will be an offence and is liable to a fine and/or imprisonment. Chemical wastes must be treated using on-site plant as licensed by the EPD or with engaging a licensed collector to transport the wastes to a licensed facility. For each consignment of wastes, the waste producer, collector and disposer of the wastes must sign all relevant parts of a computerised trip ticket so as to trace wastes from production to disposal.
12.2.3.3 This regulation also prescribes the storage facilities to be provided on-site including the labeling and warning signs. In order to minimise the risks of pollution and danger to human health and life, waste producers are required to prepare and make available written emergency procedures for any spillage, leakage or accidents arising from storage of chemical wastes, and waste producers must also provide employees with training for such procedures.
12.2.4 Dumping at Sea Ordinance
12.2.4.1 The relevant legislation and guidelines for the disposal of contaminated sediment at marine disposal sites are listed below.
· Dumping at Sea Ordinance (Cap.466);
· Environment, Transport and Works Bureau Technical Circular (Works) No.34/2002 Management of Dredged /Excavated Sediment; and
· Works Bureau Technical Circular (WBTC) No. 12/2000 Fill Management.
12.2.4.2
The Dumping at Sea
Ordinance (DASO) is the major statutory legislation to control dumping of
sediment at sea and safeguards the water quality and ecology of the
12.2.4.3 The ETWB TC(W) No.34/2002 was adopted in August 2002 to supersede Work Bureau Technical Circular (WBTC) 3/2000 which was promulgated for the purpose of assessing the disposal requirements for dredged sediment. The ETWB TC(W) No.34/2002 sets out the procedures for seeking approval from the EPD to dredge/excavate sediment and the management framework for marine disposal of such sediment. It covers the approval of the dredging/excavation proposals and marine disposal of the dredged/excavated sediment. It does not cover the use of dredged/excavated sediment to form land, but such dredging and reclamation works must satisfy the requirements of the EIAO. Application for the approval of dredging/excavation proposals and allocation of the marine disposal space shall be made to the Secretary of Marine Fill Committee (MFC). The allocation of sediment disposal sites would not be considered until the need for removal of such sediment has been satisfactorily demonstrated. The rationale for sediment removal should, therefore, be provided to the Secretary of MFC for agreement.
12.2.4.4 The ETWB TC(W) No. 34/2002 also establishes guidelines for the classification of sediment based on their contaminant levels, including:
· Metals (cadmium, chromium, copper, mercury, nickel, lead, silver and zinc);
· Metalloid (arsenic); and
· Organic micro-pollutants (polycyclic aromatic hydrocarbons, Polychlorinated biphenyls, and tributyltin).
12.2.4.5 Currently there are two sets of chemical criteria for assessing the contamination levels of sediment:
· Lower Chemical Exceedance Level (LCEL); and
· Upper Chemical Exceedance Level (UCEL).
12.2.4.6 The LCEL is intended to represent levels below which adverse biological effects (or ecotoxicity) are considered to be unlikely. The UCEL, on the other hand, is intended to represent a level beyond which adverse biological effects are considered likely to occur. These criteria therefore represent a convenient means to broadly characterise sediment quality and identify potentially polluted sediments that might be of concern if they are disturbed in the course of the Project. The LCEL and UCEL for the contaminants of interest are presented in Table 6.4 below.
Table 6.4 Sediment Quality Criteria for Classification of Sediment under ETWB TC(W) No.34/2002
Contaminants |
Lower Chemical Exceedance Level (LCEL) |
Upper Chemical Exceedance Level (UCEL) |
Metals (mg/kg dry wt.) |
||
Cadmium (Cd) Chromium (Cr) Copper (Cu) Mercury (Hg) Nickel (Ni)* Lead (Pb) Silver (Ag) Zinc (Zn) |
1.5 80 65 0.5 40 75 1 200 |
4 160 110 1 40 110 2 270 |
Metalloid (mg/kg dry wt.) |
||
Arsenic (As) |
12 |
42 |
Organic-PAHs (μg/kg dry wt.) |
||
Low Molecular Weight PAHs High Molecular Weight PAHs |
550 1700 |
3160 9600 |
Organic-non-PAHs (μg/kg dry wt.) |
||
Total PCBs |
23 |
180 |
Organometallics (μg TBT/l in Interstitial water) |
||
Tributyltin* |
0.15 |
0.15 |
* Contaminant level is considered to exceed UCEL if it is greater than the value shown.
12.2.4.7 Based on these criteria, the sediment is classified into Category L (low contamination level), Category M (medium contamination level) or Category H (high contamination level). The ETWB TC(W) No.34/2002, also, stipulates a three-tiered screening for sediment assessment for determining the disposal options as shown in Figure 6.3.
· Category L: Sediment with all contaminant levels not exceeding the LCEL. The material must be dredged, transported and disposed of in a manner which minimises the loss of contaminants either into solution or by resuspension.
· Category M: Sediment with any one or more contaminant levels exceeding the LCEL and none exceeding the UCEL. The material must be dredged and transported with care, and must be effectively isolated from the environment upon the 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 the final disposal.
12.2.4.8 The detailed description of the 3-tier approach is described as follows:
· Tier I screening is a desktop screening process to review the available information and determine whether the sediment of concern belongs to Category L material suitable for open sea disposal. If there is insufficient information to arrive at such conclusion, Tier II chemical screening shall proceed directly.
· Tier II screening is a chemical screening process to categorise sediment based on its chemical contaminant levels and to determine whether the sediment is suitable for open sea disposal without further testing. Upon Type II screening, the sediment shall be classified as Category L, M or H material. There are three types of disposal options: Types 1, 2 and 3 disposal represent open sea disposal, confined marine disposal and special treatment/disposal respectively. Category L material is suitable for open sea disposal, but Categories M and H will require Tier III screening to further determine the disposal option.
· Tier III screening is a biological screening process to identify the most appropriate disposal option for Category M (either Type 1 or 2) and certain Category H sediment (either Type 2 or 3). Sediment classified as Category M shall be subjected to the following three toxicity tests: (i) 10-day burrowing amphipod toxicity test; (ii) 20-day burrowing polychaete toxicity test; and (iii) 48-96 hour larvae (bivalve or echinoderm) toxicity test.
12.2.4.9 The WBTC No. 12/2000 defines the responsibilities of the MFC and Public Fill Committee (PFC). It also sets out the terms of reference and membership of the two committees and provides explanation on the management of fill resources, construction and demolition material, and dredged/excavated sediment disposal.
12.2.5 Public Cleansing and Prevention of Nuisances Regulation
12.2.5.1 This regulation provides further control on the illegal dumping of litter or waste in streets and public places (including water courses, streams, channels etc). Any offence of this regulation would result in a fine and/or to imprisonment.
12.2.6 Other Relevant Guidelines
12.2.6.1 The following guidelines also relate to waste management and disposal:
· Technical Memorandum on Environmental Impact Assessment Process (TM-EIAO), Annex 15 – Guidelines for Assessment of Waste Management Implications, and Annex 7 – Criteria for Evaluating Waste Management Implications;
· Waste Reduction Framework Plan, 1998-2007, Planning Environment and Lands Branch, Government Secretariat (1998);
· Waste Disposal Plan for Hong Kong (1989);
· Hong Kong Planning Standards and Guidelines (HKPSG), Chapter 9 – Environment;
· Code of Practice on the Packaging, Labeling and Storage of Chemical Wastes, EPD (1992);
· New Disposal Arrangement for Construction Waste (1992), Environmental Protection Department & Civil Engineering Department;
· Practice Note for Professional Persons – Construction Site Drainage (ProPECC PN 1/94), Professional Persons Consultative Committee (1994);
· Works Branch Technical Circular (WBTC) No. 32/92, The Use of Tropical Hard Wood on Construction Site;
· WBTC No. 2/93, Public Dumps;
· WBTC No. 2/93B, Public Filling Facilities;
· WBTC Nos.25/99, 25/99A and 25/99C, Incorporation of Information on Construction and Demolition Material Management in Public Works Sub-committee Papers;
· WBTC No. 19/2001, Metallic Site Hoardings and Signboards;
· WBTC No. 12/2000, Fill Management, Hong Kong SAR Government;
· WBTC Nos. 6/2002 and 6/2002A, Enhanced Specification for Site Cleanliness and Tidiness. Works Bureau, Hong Kong SAR Government;
· WBTC No. 12/2002, Specification Facilitating the Use of Recycled Aggregates. Works Bureau, Hong Kong SAR Government;
· ETWB TC(W) No. 33/2002 Management of Construction and Demolition Material Including Rock;
· ETWB TC(W) No. 34/2002 Management of Dredged/ Excavated Sediment;
· 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.
12.2.6.2 According to ETWB TC(W) No. 33/2002, for Designated Projects, a Construction and Demolition Material Management Plan (C&DMMP) should be submitted, together with the Environmental Impact Assessment (EIA) Report to the Public Fill Committee (PFC) for approval in case C&D materials exceed 50,000m³.
12.2.6.3 The ETWB TC(W) No. 19/2005 also sets out the policy and procedures requiring contractors to prepare and implement an environmental management plan to encourage on-site sorting of C&D materials and to reduce C&D waste generation during construction.
12.2.6.4 ETWB TC(W) No. 34/2002 stipulates the procedures for seeking approval to dredged sediment and the management framework for marine disposal of such sediment (see Section 6 of this EIA report for further details). Applications for approval of dredging proposals and allocations of marine disposal shall be made to the Secretary of Marine Fill Committee (MFC). Marine Dumping Permits as stipulated under the Dumping at Sea Ordinance are required from the EPD for the disposal of dredged sediment. Details of the assessment methodology have been provided in Section 12.2.4 above.
12.3.1.1 The assessment of the environmental impacts from the handling, storage, collection, transportation and disposal of waste material generated by the project has been undertaken in accordance with Annex 7 and Annex 15 of the TM-EIAO.
12.3.1.2 The waste management hierarchy has been applied in the assessment and development of mitigation measures for waste. The waste management hierarchy is a concept which shows the desirability of various waste management methods and comprises the following in order of preference:
· avoidance;
· minimisation;
· recycling/reuse;
· treatment; and
· disposal.
12.3.1.3 All opportunities for reducing waste generation have been assessed based upon the following factors:
· avoiding or minimising waste generation through changes in the design;
· adopting better management practices to promote segregation of waste materials;
· reuse and recycling; and
· diverting waste to public dumps or other construction sites.
12.3.1.4 The types and quantities of waste have been estimated and disposal options for each category of waste identified, taking into account the existing or future spare capacities of the waste disposal facilities and the environmental implications of the handling, collection and disposal of waste material. The potential environmental impacts associated with the handling, transportation and disposal of waste arising from the construction works will be assessed with reference to the following approach:
· estimation of the types, timing and quantities of the wastes to be generated and fill to be imported; and
· assessment of the potential environmental impacts on the capacity of waste collection, transfer and disposal facilities.
12.4 Construction Phase Waste Management Assessment
12.4.1 Wastes Types
12.4.1.1 The construction of the TM-CLKL will involve a number of activities which will generate wastes which can broadly be classified into distinct categories based on their nature and the options for their disposal. These include:
· Marine dredged sediment, including material from the seawall, reclamation and marine and land viaduct and building foundation construction;
· Excavated construction and demolition (C&D) materials suitable for public fill, including the alluvium from the tunnel construction;
· Construction and demolition waste, including cleared vegetation, which is not suitable for public fill;
· Chemical waste;
· Sewage; and
· General refuse.
12.4.1.2 In accordance with the ETWB TC(W) No.33/2002A, a C&DMMP has, also, been prepared. The preliminary quantities and nature of the wastes predicted to be generated by the project have been estimated in the C&DMMP, which has been endorsed by the Public Fill Committee.
12.4.2 Details of Works Activities
12.4.2.1 As described in Section 3, the TM-CLKL project comprises mostly marine works with reclamations, a tunnel and a marine viaduct proposed to be constructed in the marine environment. The construction of northern and southern landfall reclamations is required to provide protection to the tunnel structure and landing area for construction of the launching shaft for the TBM. Details of the construction are also provided in Section 3 and summarised here. For the seawalls construction, a fully dredged method for the seawall foundations is proposed. Both landfalls are elongated in shape and have been subdivided into three portions to accommodate the TBM tunnel and shaft, cut-and-cover tunnel and the open ramp and connecting road at ground level. It is proposed that the end sections (tips) of the reclamations are constructed using the fully dredging method as these areas will be required to house the TBM tunnel shafts and the deeper portion of the cut-and-cover tunnel sections.
12.4.2.2 For the inner portions of the reclamations, where the cut-and-cover sections and open ramps will be constructed above the marine deposit, non-dredged reclamation is proposed in order to minimise the sediment dredging and disposal quantities. As such, marine deposits underneath the cut-and-cover tunnel and ramp will be left in place and band drains and a sand blanket will be installed. The marine sediments would all require disposal to a suitable marine disposal location either in Hong Kong or in the Mainland.
12.4.2.3 Public fill will be used for the reclamation of the northern landfall. For the southern landfall reclamation, public fill will be used above +2.5 mPD, while a maximum of 30% public fill (the rest being sand fill) will be used below the water mark. Backfilling of the trench for constructing the seawall will, also, use 50% public fill and 50% rock fill for northern landfall, and 50% sand fill and 50% rock fill for southern landfall. A sensible balance has been struck between maximizing the use of public fill and the need to reduce water quality impact as well as to control settlement for the new reclamations. In respect of the latter, only sand fill could be effectively compacted below water, therefore is preferred to be used below the mean high water level of +2.5 mPD. Public fill will create a larger water quality impact owing to the higher fines content. Furthermore, the reclamation for the southern landfall will be constructed together with the reclamation for HKBCF under the same construction contract. Therefore the reclamation methodology and assumptions for the southern landfall shall tally with those of the HKBCF project.
12.4.2.4 Surcharge to a height of 3.0 – 7.5m will be placed on the newly reclaimed land at both the northern and southern landfalls to control the residual settlement of the reclamation and such material will be imported. As the reclamation works would require fill materials, the handling and disposal of such materials and wastes will require proper management in order to minimise any environmental impacts and nuisances arising.
12.4.2.5 The tunnel will be constructed using TBM and will be at a depth of approximately - 49mPD at its deepest point and -42mMPD at the tunnel axis. As such, the material to be removed will not be marine mud but largely comprise alluvium material and some Completely Decomposed Granite (CDG) and this material would be suitable for use as public fill, if treated and dewatered first. Construction of the marine viaduct would also generate some sediment and also some small quantities of alluvium and CDG material.
12.4.2.6 Notwithstanding the marine works, the TM-CLKL project, also, comprises the construction of land based elements including the toll plaza at Tuen Mun Area 46 including a short tunnel underpass and works for the land based viaducts, slope works and utilities. The proposed toll plaza area is proposed to be located on land that is already generally formed and as such while significant excavation is not required, with the exception of the short underpass tunnel and peripheral slopes, fill material will be needed to form the toll plaza layout. While no buildings will be demolished as a result of the project, excavation for the viaduct piers, removal of road surfacing, utility installation and diversions and slope upgrading will generate some construction and demolition material, although the amounts should be relatively small.
12.4.2.7 The nature and preliminary quantities of the various waste and fill materials generated and required for the projects are discussed below.
12.4.3 Marine Dredged Sediment
12.4.3.1 It should be noted that both non-dredged and fully dredged methods for the construction of the southern and northern tunnel landfall reclamations have been considered taking into account various aspects including environmental, engineering practicability and proven technology. Details of this are summarised above and provided in Section 2 of this report. It has been concluded that the dredging for the seawall foundations and the end sections of both reclamations, where the TBM launching area will be constructed, will be inevitable, but that a non-dredged method comprising the use of band drains can be adopted for the remaining reclamation areas in order to minimise the amount of marine dredged sediment generated and requiring disposal. The proposed dredging rationale has received no objection from the Marine Fill Committee (MFC).
12.4.3.2 In order to determine the nature of the sediment to be excavated, a marine ground investigation (GI) including sediment sampling and laboratory testing has been undertaken, in accordance with the requirements in ETWB TC(W) No.34/2002. A summary of the results are provided in Appendix D1 and discussed below.
12.4.3.3 A total of 23 sub-samples at 10 vibrocore locations had been collected (Figure 6.7). Chemical and biological tests were undertaken in accordance with the requirements as set out in the ETWB TC(W) No.34/2002. With reference to the chemical tests under the ETWB TC(W) No.34/2002, 18 samples exhibited compliance with the LCEL, but 5 samples showed exceedance of LCEL, which required biological tests to confirm their disposal options. The chemical exceedance included metal (Pb), metalloid (As) and micro-organic pollutants (high molecular weight PAHs) concentrations. All of the 4 samples with exceedance of LCEL passed the biological test. In summary, two classifications of sediment material where identified, comprising Category L and Category M, that passes the biological testing (Mp). As noted in Section 12.2.6.6, the material is suitable for disposal in Type 1 open sea and Type 1 Open Sea (Dedicated) disposal. Figure 12.1 shows the interpretation of the demarcation of contaminated sediment.
12.4.3.4 Table 12.1 below summarises the estimated quantities of each of these classifications of the marine sediment that are anticipated to arise during the TM-CLKL project construction period. In addition, Table 12.2 summarises the proposed disposal options for the sediment based upon its contamination classification. In estimating the volumes of material, a bulking factor of 30% has been assumed.
Table 12.1 Summary of Marine Sediment Disposal Programme
Sediment Quantity |
Volume in Million Cubic Metres (Mm3) (bulk volume with 30% bulk factor) |
Total |
||||||
2010 |
2011 |
2012 |
2013 |
2014 |
2015 |
2016 |
Mm3 |
|
Type 1 Disposal - Open Sea (Class L) within Hong Kong* |
- |
0.64 |
0.69 |
0.04 |
0.05 |
0.04 |
- |
1.46 |
Type 1 Disposal - Open Sea (Class L) to Mainland China* |
- |
0.94 |
1.51 |
0.56 |
0.03 |
0.01 |
- |
3.05 |
Type 1 Disposal - Open Sea Dedicated Site (Class Mp) to Mainland China* # |
- |
- |
0.36 |
0.37 |
- |
- |
- |
0.73 |
Total: |
|
|
|
|
|
|
|
5.24 |
Notes: * Classification of sediment material in accordance with ETWB TC(W) No.34/2002. Mp = Cat M materials passing the biological screening; Mf = Cat M materials failing the biological screening.
# All Category Mp material is derived from the southern landfall and along the southern viaduct alignment
Table 12.2 Summary of Marine Sediment for Disposal
Source/Activity |
Disposal Method |
Category* |
Disposal Quantity in Mainland China |
Disposal Quantity within Hong Kong |
Total Disposal Quantity |
Mm3 (bulk volume with 30% bulk factor) |
|||||
A) Dredged material for Seawall |
Type 1 Disposal - Open Sea |
L |
3.05 |
1.36
|
4.41 |
Type 1 Disposal - Open Sea Dedicated Site |
Mp |
0.73 |
0 |
0.73 |
|
Type 2 Disposal - Confined Marine Disposal |
Mf |
0 |
0 |
0 |
|
B) Marine Bridge Foundation # |
Type 1 Disposal - Open Sea |
L |
0 |
0.1 |
0.1 |
Type 1 Disposal - Open Sea Dedicated Site |
Mp |
0 |
0 |
0 |
|
Type 2 Disposal - Confined Marine Disposal |
Mf |
0 |
0 |
0 |
|
C) Tunnelling |
Type 1 Disposal - Open Sea |
L |
0 |
0 |
0 |
Type 1 Disposal - Open Sea Dedicated Site |
Mp |
0 |
0 |
0 |
|
Type 2 Disposal - Confined Marine Disposal |
Mf |
0 |
0 |
0 |
|
Total |
Type 1 Disposal - Open Sea |
L |
3.05 |
1.46 |
4.51 |
Type 1 Disposal - Open Sea Dedicated Site |
Mp |
0.73 |
0 |
0.73 |
|
Type 2 Disposal - Confined Marine Disposal |
Mf |
0 |
0 |
0 |
|
|
Grand Total: |
|
3.78 |
1.46 |
5.24 |
Notes: * Classification of sediment material in accordance with ETWB TC(W) No.34/2002. Mp = Cat M materials passing the biological screening; Mf = Cat M materials failing the biological screening.
# The disposal quantity under this category of source/activity includes marine sediment during the foundation works in land-based activities (i.e., land bridges / viaducts / slip roads, administration building, other tunnel ancillary buildings, etc. The quantities for those activities are anticipated to be insignificant.
12.4.3.5 While the sediment has been shown to be overall uncontaminated in nature, the dredging operations, handling and disposal of the sediment may cause impacts to the marine environment and ecology if proper management measures are not implemented. Dispersion of suspended solids and release of contaminants from the dredging operation and dredged sediment into the water column may cause significant consequences, e.g. adverse effects to marine organisms and food chain. A quantitative assessment of potential impacts relating to the water quality from the disturbance to the sediment during dredging activities has been undertaken and reported in the Section 6 of this report. Agreement is being sought between the Mainland government and the Hong Kong government to accept the total disposal quantity for the two projects.
12.4.3.6 Based upon the above tables, individual quantities of sediment for open sea disposal and confined marine disposal have been estimated based on the chemical and biological tests results. It is proposed to dispose of all the Category Mp (0.73Mm3) and about 68% of the Category L material (3.05Mm3) to China, with the remaining Category L (1.46Mm3) being proposed to be disposed of in a Type I Open Sea Disposal site in Hong Kong. The quantity of Category L material proposed to be disposed to China arises from the southern reclamation, which is anticipated to form a combined construction contract with the HKBCF. Owing to the huge volume of dredged sediment involved in HKBCF, it is their intention to dispose this material to China. The marine sediment disposal arrangement and dredging methodology for the project of HKBCF, HKLR and TM-CLKL were discussed with MFC on 4 March, 25 March and 10 June 2009. In the proposed methodology, best endeavour has been made to minimize dredging and thus the amount of mud generation. MFC had no further comments. On the basis of these discussions, the project proponent submitted an application on 3 April 2009 to the South China Sea Branch of the State Oceanic Administration for the cross-border disposal of marine sediments, and the remainder of marine sediments will be disposed within Hong Kong.
12.4.3.7 Disposal of sediment in Hong Kong waters will be controlled under the DASO. It should be noted that in accordance with the DASO, the requirements as stipulated in the ETWB TC(W) No.34/2002 should be strictly followed prior to the dredging and disposal of sediment. Preliminary testing for the marine sediments have been carried out and the results are attached at Appendix D1. The Sediment Quality Report will be prepared in due course, in accordance with ETWB TC(W) No. 34/2002.
12.4.3.8 Type I Open Sea Disposal areas in Hong Kong are located at South of Cheung Chau, South of Tsing Yi, East of Ninepins and East of Tung Lung Chau, although it should be noted that the South of Tsing Yi and East of Tung Lung Chau are not currently in operation and the East of Ninepins would only be operated from mid March to end September each year. On-going monitoring of these pits has shown that disposal of Category L material in these locations should not result in any unacceptable impacts to the water quality or ecological receivers in the area. With proper preventive and mitigation measures in place for handling, transport and disposal as per the requirements given in the ETWB(W) No.34/2002, no insurmountable environmental impacts would be anticipated.
12.4.4 Construction and Demolition Materials
12.4.4.1 Construction and demolition (C&D) materials generated during construction will comprise materials that are suitable for reuse on site or as public fill and a portion of waste material that will require disposal to a licensed landfill facility. For the purposes of this assessment, these two fractions are denoted C&D material and C&D waste and are discussed below.
C&D Materials Generated
12.4.4.2 The Construction and Demolition (C&D) materials generated from the TM-CLKL project will comprise the following:
· Alluvium and CDG from the submarine tunnel and foundations of the marine viaduct bridge piers and administration and other tunnel ancillary buildings;
· Excavation of reclamation materials for cut and cover tunnel, portal and ventilation building;
· Surplus surcharge from the reclamation works;
· Excavation materials from the land viaduct construction, slope cutting, utility diversions, site formation of the toll plaza and administration buildings formation; and
· Road and pavement demolition waste from the modification of the existing roads for new roads connections.
12.4.4.3 In accordance with the waste hierarchy presented in Section 12.3, it is necessary to consider all ways to avoid the generation of material and also reuse within the project. The following methods have been adopted:
Minimising Generation of C&D Materials
· Optimisation of the tunnel profile: The tunnel profile has been minimized whilst maintaining adequate space for the structural gauge, ventilation spatial requirement and permanent support envelope; and
· Optimisation of slope angle: Slope angles for site formation and slope works have been maximised in order to reduce the amount of spoil and to minimize the footprint of the works.
Maximising Use of C&D Materials
· A large extent of site formation works needs to be carried out in the toll plaza area. Inert C&D materials from the project are proposed to be reused at this location for construction of the raised platform for the toll plaza; and
· The C&D materials generated by construction of cut slopes along the hill side of the NLH at North Lantau and that adjacent to the proposed toll plaza at Tuen Mun will be absorbed by the site formation of the toll plaza.
12.4.4.4 However, according to the latest programme, the reclamation of northern and southern landfalls will commence and be completed at similar time and, therefore, most of the surcharge for the reclamation cannot to be reused for the permanent works. Notwithstanding, the reclamation works have been programmed to reuse a small proportion of the surplus surcharge, and the remaining will have to be removed back to the fill banks to be reused in other construction works.
12.4.4.5 A summary of the C&D materials anticipated to arise from the TM-CLKL project given in Table 12.3. The majority of the soft C&D material and the surcharge material given in Table 12.3 will not be reused on site and as such will be surplus and removed off-site to the fill banks, as discussed further below. However, it is proposed that the small amounts of the materials for the cut slopes and the excavated materials from road pavement demolition, will be reused. Table 12.4, however, provides a tentative disposal programme of the surplus material only.
Table 12.3 Summary of C&D Materials Arising from the Project
Material Type |
Volume (M m3) |
Remarks |
C&D soft materials |
||
Bridge and building foundations |
0.59 |
Deep marine viaduct foundations and portal and ventilation buildings at the landfalls |
Material from TBM |
1.48 |
Mainly alluvium materials generated from TBM tunnel, |
Material from cut and cover tunnel sections |
0.62 |
Cut and cover sections of tunnel at the landfalls |
Cut slopes |
0.56 |
Removal of material for cut slopes in Lantau and for the toll plaza |
Sub-Total |
3.25 |
|
Others |
||
Surplus surcharge |
1.32 |
Materials generated from removal of surcharge at landfalls |
Excavation materials |
0.03 |
Demolition of road pavement and utility diversions |
Sub-Total: |
1.35 |
|
TOTAL |
4.60 |
|
Remark: All figure exclude marine sediment generated by tunneling and foundation works
Table 12.4 Summary of Surplus C&D Materials Disposal Programme
Material Type |
Volume (M m3) |
Total (M m3) |
||||||
2010 |
2011 |
2012 |
2013 |
2014 |
2015 |
2016 |
||
Surplus C&D soft materials# |
- |
- |
- |
0.85 |
0.90 |
0.69 |
0.25 |
2.69
|
Surplus surcharge @ |
- |
- |
- |
- |
1.17 |
- |
- |
1.17 |
Remark: All figure exclude marine sediment generated by tunneling and foundation works
Note # Excludes material generated by cut slopes and road pavement demolition of 0.56Mm3 and 0.03 Mm3 respectively which shall be reused in project.
@ Excludes 0.15Mm3 to be reused in project.
12.4.4.6 As noted above, the majority of the soft C&D material (2.69Mm3) will be suitable for public fill after treatment and will be transferred to the Tuen Mun Area 38 fill bank by barge or by truck. The alluvium and small amounts of CDG material generated by the TBM tunnelling, portion of the cut and cover tunnel excavation as well as deeper sections of the marine viaduct piles will need to be treated at a Slurry Treatment Plant located on the northern landfall. However, because of programming reasons, the inert C&D material of alluvium in nature is suggested to be delivered to fill bank for further processing before using as public fill materials. The material will likely be transferred to the fill bank by barge or by truck but as the fill bank is in the vicinity of the works area, significant impacts from the additional marine traffic are not expected.. While for the surcharge mound, it is suggested to be delivered to the Hong Kong-Zhuhai-Macao Bridge - Hong Kong Boundary Crossing Facilities and SENT Landfill Extension subject to further coordination.
12.4.4.7 The purpose of the slurry treatment plant (STP) is to recycle the slurry to be re-used but not to lower the moisture content of the spoil. In the TM-CLKL case, two types of spoil, which is slurry mixed alluvium, are expected to be generated from the excavation in soil/soft ground by the slurry TBM. The return slurry will be recycled in the slurry treatment plant. When excavating in ground with high sand and gravel contents, the return slurry is recycled with coarser particles such as gravel and cobbles being separated by a shaker while the sands and fines are separated by hydrocyclones. The coarser sandy material (typically comprising 80% of the material) will come out from the de-sander units while the slurry (remaining 20%) is recycled to be re-used and pumped back to holding tanks. This type of spoil with high sand content tends to be relatively drier, and can be disposed to public fill after the slurry treatment.
12.4.4.8 When excavating in ground with high silt and clay contents, the return slurry is mainly recycled by centrifuges. It is more difficult to completely separate the slurry from the silts and, as a result, the material is eventually dumped into the spoil basin. The process will produce finer silty and clayey spoil material with a higher moisture content coming out from the centrifuges. Where required, the material shall be scarified to ensure it is "suitably" dried before they can be disposed of to the fill bank. The first phase of reclamation has been planned to provide sufficient space for housing the tunnel launching shaft and to accommodate the STP as well as the spoil basin for the drying of material before disposal. This principle of disposal has been agreed at the PFC meeting in March 2009 when the C&D materials disposal proposal for the project was discussed.
12.4.4.9 The surplus surcharge material from both the southern and northern landing reclamations will, also, be transferred to the Tuen Mun Area 38 fill bank by barge or by truck.
12.4.4.10 Some of the C&D material generated by the project will be reused on site. A quantity of 0.44Mm3 out of the 0.56Mm3 of the C&D materials predicted to be generated during the construction of the cut slopes in Tuen Mun Area 46 is expected to be reused in the site formation of the toll plaza at Tuen Mun. As the material will only be reused locally, impacts from transportation are not expected. The balance of the excavated quantity of 0.12Mm3 is proposed to be used in northern reclamation works. The material will be transferred by lorry over a 12 month period between July 2012 and June 2013 (see the overall construction programme in Section 3) to the northern reclamation for use. Given the relatively small quantities involved and an average truck capacity of 7.5m3 a total of 16,000 would be needed over this period. Based upon the material being exported on a regular basis for the majority of the 12 month period, say 8 months, this would equate to around 77 trips per day, assuming a 6 day working week. The material would be transported via Lung Mun Road and Lung Fu Road which are already heavily utilised and, as such, this additional traffic is not expected to cause any additional impacts to sensitive receivers along this route. However, the material will need to be carefully stockpiled if it cannot be reused directly to avoid dust and other nuisance impacts
12.4.4.11 Similarly, 0.16Mm3 of C&D materials generated from the cut slopes at NLH is proposed to be reused in the northern reclamation works. Transport of the material will be by barge and environmental impacts are expected to be minimal.
12.4.4.12 Material from artificial hard standing and the slopes on Tuen Mun is, also, proposed to be reuse for the site formation of the toll plaza at Tuen Mun and new pavement areas. As the material will only be reused locally, impacts from transportation are not expected. However, the material will need to be carefully stockpiled if it cannot be reused directly to avoid dust and other nuisance impacts.
Fill Materials Required
12.4.4.13 The TM-CLKL project requires fill materials for both permanent (for example, toll plaza platform) and temporary (reclamation surcharge) uses and the materials are proposed to obtained from both reuse of the material generated by the project as described above and newly imported material.
12.4.4.14 Areas where generated material will be reused include:
· raised platform for the toll plaza;
· some rock armour from the existing seawall will be reused on the new sloping seawall as far as possible; and
· new pavement.
12.4.4.15 A total of 0.74Mm3 will be reused, which not only negates the need for off-site disposal but also, minimises the amount required to be imported.
12.4.4.16 Imported materials, however, will be needed for the construction of seawalls, reclamation and landscaping works. Though the rock armour from the existing seawall will be reused on the new sloping seawall as far as possible, additional rock armour will be required due to the increased extent of the new sloping seawall. A summary of the fill materials anticipated to be required for the TM-CLKL project is given in Table 12.5. On-going coordination with MTR Corporation is undergoing to use some of the C&D materials generated from their concurrent projects, including Hong Kong Section of Guangzhou-Shenzhen-Hong Kong Express Rail Link, South Island Line (East), Shatin to Central Link, and Kwun Tong Line Extension, where these are suitable for use as fill and surcharge materials for this project. Table 12.5A shows a tentative programme of when these materials are expected to be available from other project sources, which is subject to final allocation of PFC.
Table 12.5 Summary of Required Fill Materials
Material Type |
Quantity (Mm3) |
||
Total |
Imported |
Reused from Project |
|
Rock (excluding armour rock) for seawall |
2.59 |
2.45 |
0.14 from toll plaza and NLH cut slopes (rock) |
Rock armour for seawalls |
0.35 |
0.35 |
- |
Sandfill for southern reclamation |
3.20 |
3.20 |
- |
Public fill for southern reclamation |
3.27 |
3.27 |
- |
Public fill for northern reclamation |
2.04 |
1.88 |
0.15 from surcharge and 0.01 from road pavement demolition |
Public fill for Surcharge |
1.32 |
1.32 |
- |
Public fill for toll plaza formation |
0.44 |
- |
0.44 from toll plaza and NLH cut slopes |
Total (Mm3) |
13.21 |
12.47 |
0.74 |
Table 12.5A Tentative Programme of Fill Materials Required and Sources of Materials
|
Imported Quantity (Mm3) |
Total |
||
Material Type |
2011 |
2012 |
2013 |
Mm3 |
Rock (excluding armour rock) for seawall |
0.65 |
1.80 |
|
2.45 |
Sources: |
XRL |
SCL, XRL |
|
|
Rock Armour for seawall |
|
0.32 |
0.03 |
0.35 |
Sources: |
|
Contractor’s own source |
|
|
Sandfill for reclamation |
|
1.77 |
1.43 |
3.2 |
Sources: |
|
Contractor’s own source |
|
|
Public fill for reclamation |
|
2.17 |
2.98 |
5.15 |
Sources: |
|
XRL |
SIL(E), SCL, KTE, XRL, CKR |
|
Public fill for surcharge |
|
0.34 |
0.98 |
1.32 |
Sources: |
|
XRL |
SIL(E), SCL, KTE, XRL, CKR |
|
Notations:
(1) SIL(E): MTR’s South Island Line (East)
(2) SCL: MTR’s Shatin to Central Link
(3) KTE: MTR’s Kwun Tong Line Extension
(4) XRL: MTR’s Express Rail Link
(5) CKR: HyD’s Central Kowloon Route
12.4.4.17 Based upon the predicted total quantities of C&D material to be ultimately disposed of off-site of about 4.0Mm3, as compared to the material to be newly imported, the balance is about 8.5Mm3 required to be imported. All measures have been employed for minimisation and reuse and as detailed above, the disposal of the surplus material will be to the Tuen Mun fill bank for ultimate reuse and as such will not affect the capacity of Hong Kong’s landfills. Transportation of the material is not expected to yield unacceptable impacts.
C&D Waste
12.4.4.18 In addition to the C&D materials that will be generated by the project and will be suitable for reuse as public fill, some C&D waste will be generated during the construction phase. These materials will include:
· Cleared vegetation;
· Wood from formwork;
· Unusable cement mixes; and
· Damaged or contaminated construction materials.
12.4.4.19 The volume of C&D waste generated by the project will be dependant on specific operating procedures and site practices and, is expected to be small at about 0.15Mm3. The use of steel falsework instead of wood has been a cost-effective practice in the industry. As steel falsework is a proprietary system, it will be reused throughout the project and subsequent projects. The use of steel will substantially reduce the amount of waste wood that the project will generate. In addition, as the TM-CLKL project will be largely constructed either in the marine environment or on already developed or reclaimed land, the amount of C&D waste generated from site clearance comprising a mixture of topsoil and vegetative matter is expected to be small.
12.4.4.20 The other types of C&D waste are, also, expected to be limited, with only small quantities of maintenance and packaging waste being generated. Given that the material will be generated will be of in small quantities, significant impacts associated with its handling and disposal are not expected.
12.4.4.21 Measures to minimise the generation of waste shall be implemented and demolition waste shall be sorted to avoid contamination of the materials suitable for public fill but significant impacts are not predicted from the handling, storage or disposal of this material.
12.4.5.1 Chemical wastes likely to arise from the construction activities for the TM-CLKL and the associated facilities would include:
· Scrap batteries or acid/alkali from maintenance activities;
· Used paints, engine oils, hydraulic fluids and waste fuel;
· Spent mineral oils/cleansing fluids from machineries; and
· Spent solvents/solutions, some of which may be halogenated, from equipment cleansing activities.
12.4.5.2 Chemical wastes may pose environmental, health and safety hazards if not stored and disposed of appropriately as outlined in the Waste Disposal (Chemical Waste) (General) Regulation and the Code of Practice on the Packing, Labeling and Storage of Chemical Waste. These hazards may include:
· Toxic effects to workers;
· Adverse effects on air quality, water quality and land contamination due to spillage;
· Hazards of fire; and
· Disruption of sewage treatment works should the chemical waste enter the sewerage system.
12.4.5.3 It is difficult to quantify the amount of chemical waste as it would be highly dependent on the Contractor’s on-site maintenance practices and the number of mechanical plant and vehicles utilised on-site. However, it is anticipated that the quantity of chemical waste arising during the construction of this project would be relatively small and if handled, stored, transported and disposed of in an appropriate manner, no impacts are predicted.
12.4.5.4 Notwithstanding, the future Contractor should register to the EPD as a Chemical Waste Producer pursuant to the Regulation and the chemical waste should be collected by licensed collectors for subsequent disposal at licensed waste disposal facilities, for example the Chemical Waste Treatment Centre in Tsing Yi.
12.4.6.1 Sewage will arise from the amenity facilities used by the construction workforce and site office’s sanitary facilities. Night soil from chemical toilets would also be generated. The sewage sludge, therefore, will need to be properly managed in order to minimise any nuisance of odour and potential health risks to the workforce by attracting pests and disease vectors.
12.4.6.2 The number of construction workers to be employed on-site is not available at this stage, but it would be anticipated to be around 430 staff (300 nos. at Tuen Mun; 100 nos. at North Lantau and 30 nos. for tunnel) in the peak period. As the workers would be scattered over various construction sites, the most cost-effective solution would be to provide adequate number of portable toilets on-site to ensure that the sewage would be properly collected for disposal. Depending on site conditions, land availability and site activities, locations and number of portable toilets would be set out in the Environmental Management Plan (EMP) in accordance with the ETWB TC(W) No.19/2005 Environmental Management on Construction Sites. No adverse waste impact would be envisaged if regular maintenance is undertaken by licensed contractors.
12.4.7.1 The presence of construction sites with workers and site offices would generate a variety of general refuse which needs disposal, which would mainly consist of food waste, aluminum cans, waste paper, etc.
12.4.7.2 The storage of general refuse has the potential to cause adverse environmental impacts, e.g. odour nuisance if the waste is not collected frequently, windblown litter, water quality impacts if the waste enters water bodies, visual impacts, etc. Construction sites may also attract pests, vermin and other disease vectors if the waste storage areas were not well maintained. Disposal of wastes at areas other than approved refuse transfer stations and landfills can also lead to similar adverse impacts.
12.4.7.3 The number of workforce (clerical and workers) to be employed for the future TM-CLKL construction project is currently not available at this stage, but it is anticipated to be about 430 staff. On this basis, the total refuse generated per day would be about 280kg/day, assuming the refuse generated rate is 0.65kg/head/day. Provided that mitigation measures are adopted, potential environmental impacts caused by the storage, handling, transport and disposal of general refuse would be expected to be insignificant. It is recommended that the general refuse should be collected on a daily basis and transferred to the closest refuse transfer stations at NWNT or north Lantau. Given the relatively small quantities of general refuse expected, adverse impacts to the operation of the refuse transfer stations and landfills would not be expected.
12.5 Operational Phase Waste Management Assessment
12.5.1.1 The operational phase of the TM-CLKL project is not be expected to generate any significant quantities of waste.
12.5.1.2 The quantities of general refuse arising from the project at this stage will be low and mainly arise from office activities and plant maintenance workshops associated with the toll plaza and ventilation buildings. Quantities of waste and chemical waste such as sediment/sludge removed from silt raps, lubrication oils, used batteries, paints and solvents are likely to be generated but the quantities will be small and insignificant. Standard good operating practice requirements should be followed in the storing, handling and transporting of any chemical wastes.
12.5.1.3 Operational sewage will be generated but, again, in relatively small quantities as summarised in Table 12.6 below, based upon the staffing estimates required for the TM-CLKL project.
Table 12.6 Estimated Sewage Generation
Location |
Staff |
Average Dry Weather Flow (m3/day) |
Southern Landfall |
10 |
3.5 m3/day |
Northern Landfall |
400 |
140 m3/day |
Toll Plaza |
110 |
38.5 m3/day |
12.5.1.4 In Tuen Mun, the sewage (Average Dry Weather Flow (ADWF)) from the toll plaza and northern ventilation building is estimated to be about 178m3 per day and with about 510 personnel on site in total. The sewage will be discharged to the existing sewerage system and it and it is expected that that adequate capacity in the local system to accommodate this amount is available
12.5.1.5 For the southern landfall ventilation building, the estimated sewage generation is very small at 3.5m3 per day (ADWF). As the quantity is so small, the sewage will be collected and pumped to the on-site HKBCF sewage treatment works located in the south-east corner of the HKBCF reclamation. The sewage treatment works will have a daily capacity of 1300m3 and an estimated throughput from the HKBCF of 700m3/day ADWF As such, it has been confirmed that there is adequate spare capacity for the limited amount of sewage generated by the TM-CLKL to be treated at this plant. The HKBCF sewage treatment plant will treat the sewage to a tertiary level before discharge via a box culvert into the marine environment.
12.5.1.6 Based upon the above, no significant waste implications during the operational phase are predicted.
12.6.1.1 Mitigation measures are required to ensure the proper handling, storage, transportation and disposal of waste is carried out. Also measures to ensure that the generation of waste is avoided and minimised and that waste materials are recycled and treated as far as practicable. The recommended mitigation measures for all categories of waste are as follows.
(i) The requirements as stipulated in the ETWB TC(W) No.19/2005 Environmental Management on Construction Sites and the other relevant guidelines should be included in the Particular Specification for the Contractor as appropriate.
(ii) The TM-CLKL Contractor should be requested to submit an outline Waste Management Plan (WMP) prior to the commencement of construction work, in accordance with the ETWB TC(W) No.19/2005 so as to provide an overall framework of waste management and reduction. The WMP should include:
- Waste management policy;
- Record of generated waste;
- Waste reduction target;
- Waste reduction programme;
- Role and responsibility of waste management team;
- Benefit of waste management;
- Analysis of waste materials;
- Reuse, recycling and disposal plans;
- Transportation process of waste products; and
- Monitoring and action plan.
(iii) The waste management hierarchy below should be strictly followed. This hierarchy should be adopted to evaluate the waste management options in order to maximise the extent of waste reduction and cost reduction. The records of quantities of waste generated, recycled and disposed (locations) should be properly documented.
(iv) A trip-ticket system should be established in accordance with ETWB(W) 31/2004 and Waste Disposal (Charges for Disposal of Construction Waste) Regulation to monitor the disposal of public fill and solid wastes at public filling facilities and landfills, and to control fly-tipping. A trip-ticket system would be included as one of the contractual requirements for the Contractor to strictly implement. The Engineer would also regularly audit the effectiveness of the system.
(v) A recording system for the amount of waste generated, recycled and disposed (locations) should be established. The future Contractor should also provide proper training to workers regarding the appropriate concepts of site cleanliness and waste management procedures, e.g. waste reduction, reuse and recycling all the time.
(vi) The CEDD should be timely notified of the estimated spoil volumes to be generated and the Public Fill Committee should be notified and agreement sort on the disposal of surplus inert C&D materials e.g. good quality rock during detailed design of the TM-CLKL project. Wherever practicable, C&D materials should be segregated from other wastes to avoid contamination and to ensure acceptability at public filling areas or reclamation sites.
(vii) The extent of cutting operation should be optimised where possible. Earth retaining structures and bored pile walls should be proposed to minimise the extent of cutting.
(viii) Inert C&D materials from slopes and road pavement will be reused for construction of the raised platform for the toll plaza where possible.
(ix) C&D materials generated by construction of cut slopes along NLH at North Lantau shall be reused in reclamation works where possible.
(x) The surplus surcharge should be transferred to a fill bank.
(xi) TMB generated alluvium and CDG material should be treated at a slurry treatment plant prior to transfer to a fill bank.
(xii) Rock armour from the existing seawall should be reused on the new sloping seawall as far as possible.
(xiii) The site and surroundings shall be kept tidy and litter free.
(xiv) No waste shall be burnt on site.
(xv) Make provisions in contract documents to allow and promote the use of recycled aggregates where appropriate.
(xvi) Prohibit the Contractor to dispose of C&D materials at any sensitive locations e.g. natural habitat, etc. The Contractor should propose the final disposal sites in the EMP and WMP for approval before implementation.
(xvii) Stockpiled material shall be covered by tarpaulin and /or watered as appropriate to prevent windblown dust and surface run off.
(xviii) Excavated material in trucks shall be covered by tarpaulins to reduce the potential for spillage and dust generation.
(xix) Wheel washing facilities shall be used by all trucks leaving the site to prevent transfer of mud onto public roads.
(xx) Dredged marine mud shall be disposed of in a gazetted marine disposal ground under the requirements of the Dumping at Seas Ordinance.
(xxi) Standard formwork or pre-fabrication should be used as far as practicable so as to minimise the C&D materials arising. The use of more durable formwork or plastic facing for construction works should also be considered. The use of wooden hoardings should be avoided and metal hoarding should be used to facilitate recycling. Purchasing of construction materials should be carefully planned in order to avoid over-ordering and wastage.
(xxii) The Contractor should recycle as many C&D materials (this is a waste section) as possible on-site. The public fill and C&D waste should be segregated and stored in separate containers or skips to facilitate the reuse or recycling of materials and proper disposal. Where practicable, the concrete and masonry should be crushed and used as fill materials. Steel reinforcement bar should be collected for use by scrap steel mills. Different areas of the sites should be considered for segregation and storage activities.
(xxiii) All falsework will be steel instead of wood.
(xxiv) Chemical waste producers should register with the EPD. Chemical waste should be handled in accordance with the Code of Practice on the Packaging, Handling and Storage of Chemical Wastes as follows:
- suitable for the substance to be held, resistant to corrosion, maintained in good conditions and securely closed;
- Having a capacity of <450L unless the specifications have been approved by the EPD; and
- Displaying a label in English and Chinese according to the instructions prescribed in Schedule 2 of the Regulations.
- Clearly labelled and used solely for the storage of chemical wastes;
- Enclosed with at least 3 sides;
- Impermeable floor and bund with capacity to accommodate 110% of the volume of the largest container or 20% by volume of the chemical waste stored in the area, whichever is greatest;
- Adequate ventilation;
- Sufficiently covered to prevent rainfall entering (water collected within the bund must be tested and disposed of as chemical waste, if necessary); and
- Incompatible materials are adequately separated.
(xxv) Waste oils, chemicals or solvents shall not be disposed of to drain.
(xxvi) Adequate numbers of portable toilets should be provided for on-site workers. Portable toilets should be maintained in reasonable states, which will not deter the workers from utilising them. Night soil should be regularly collected by licensed collectors.
(xxvii) General refuse arising on-site should be stored in enclosed bins or compaction units separately from C&D and chemical wastes. Sufficient dustbins shall be provided for storage of waste as required under the Public Cleansing and Prevention of Nuisances By-laws. In addition, general refuse shall be cleared daily and shall be disposed of to the nearest licensed landfill or refuse transfer station. Burning of refuse on construction sites is prohibited.
(xxviii) All waste containers shall be in a secure area on hardstanding;
(xxix) Aluminium cans are usually collected and recovered from the waste stream by individual collectors if they are segregated and easily accessible. Separately labelled bins for their deposition should be provided as far as practicable.
(xxx) Office wastes can be reduced by recycling of paper if such volume is sufficiently large to warrant collection. Participation in a local collection scheme by the Contractor should be advocated. Waste separation facilities for paper, aluminium cans, plastic bottles, etc should be provided on-site.
(xxxi) Training shall be provided to workers about the concepts of site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling.
12.7 Waste Disposal Recommendations
12.7.1.1 Based upon the estimated quantities and types of waste to be generated by the project, disposal options have been proposed, as detailed in Table 12.7 below. In terms of C&D waste and general refuse, both the NWNT and North Lantau refuse transfer stations have been recommended. As the project extends across both the Lantau and Tuen Mun areas, it would be preferable to remove the waste to the closest facility. The North Lantau facility has a large capacity of 900 tonnes per day permitted throughput and the NWNT transfer station is a relatively new facility, with a daily permitted throughput of 1,200 tonnes per day. As such, both facilities are considered to have sufficient spare capacity.
12.7.1.2 In terms of the waste suitable for public fill, the public fill stockpile in Tuen Mun Area 38 would represent the closest facility to the works.
Table 12.7 Recommended Waste Disposal Sites
Type of Waste |
Disposal Site |
Marine Dredged Mud |
All Category Mp and a portion of Category L material to Open Sea or Open Seas Dedicated sites in Mainland China.
Remaining Category L materials to Ninepins or South of Cheung Chau(1) |
C&D materials |
Tuen Mun Areas 38 public fill bank |
C&D waste (plastics, glass, wood, including cleared vegetation etc.) |
North Lantau Refuse Transfer Station; or NWNT Refuse Transfer Station |
Chemical waste (as defined under Schedule 1 of the Waste Disposal (Chemical Waste) Regulation) |
Chemical Treatment Facility at Tsing Yi: or Other approved facility |
General refuse |
North Lantau Refuse Transfer Station; or NWNT Refuse Transfer Station |
Note (1) Subject to DASO application
12.8 Residual Impacts
12.8.1.1 Assuming all the mitigation measures are implemented, no residual adverse impacts from the handling, storage, transportation or disposal of the waste generated by the project are predicted.
12.9 Monitoring and Audit Requirements
12.9.1.1 The assessment has concluded that the handling, transportation and disposal of waste materials during construction will not give rise to significant impacts if appropriate mitigation measures are implemented. However, it is recommended that during construction phase, regular site inspections and supervision of the waste management procedures shall be undertaken as part of the EM&A procedures, to ensure proper control, all waste is removed from site areas as appropriate and illegal disposal of waste is not being undertaken. Waste EM&A during the operational stage is not required. Further details of the specific construction phase EM&A requirements are detailed in Section 15 of this report and in the EM&A Manual.