Figures
Not used
With
reference to Chapter 2, there are three different Reprovisioning Options for the undertaking of the proposed
Project works, namely Option A, Option B, and Option C, that are being
considered for the Project. An
assessment of potential waste management implication of the three Reprovisioning Options will be discussed in this Section.
Wastes
arising from the Project are mainly from activities in the site clearance and
ground decontamination process. The options for waste minimisation, recycling,
treatment, storage, collection, transport and disposal of waste have been
examined. Environmental mitigation measures and good site practices are
recommended with reference to the applicable waste legislations and guidelines.
The following legislation which relates to the
handling, treatment and disposal of wastes in the Hong Kong SAR are applied in
the assessment of waste management implication:
ˇ Waste Disposal
Ordinance (Cap. 354)
ˇ Waste Disposal (Chemical Waste) (General)
Regulation (Cap. 354)
ˇ Waste Disposal (Charges for Disposal of
Construction Waste) Regulation (Cap. 354)
ˇ Public Health and Municipal Services Ordinance
(Cap. 132) – Public Cleansing and Prevention of Nuisances Regulation
ˇ Land (Miscellaneous Provisions) Ordinance (Cap.
28)
ˇ Dumping at Sea Ordinance (Cap. 466)
The
Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal of wastes.
Construction waste is defined as any substance, matter or thing that is
generated from construction work and abandoned, whether or not it has been
processed or stockpiled before abandoned, but does not include any sludge,
screenings or matter removed in or generated from any desludging,
desilting or dredging works. Under the WDO, wastes
can be disposed of only at designated waste disposal facilities.
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 wastes. The Environmental Protection
Department (EPD) has also issued a ‘guideline’ document, the Code of Practice
on the Packaging, Labelling and Storage of Chemical Wastes (1992), which details
how the Contractor should comply with the regulations on chemical wastes.
The
Public Cleansing and Prevention of Nuisances Regulation provides
regulatory control for illegal tipping of wastes on unauthorised (unlicensed)
sites.
The current policy related to dumping of
Construction and Demolition (C&D) material is documented in the Works
Branch Technical Circular No. 2/93, ‘Public Dumps’. C&D materials that are wholly inert,
i.e. public fill, should not be disposed of to landfill, but taken to public
filling areas, which usually form part of reclamation schemes. The Land (Miscellaneous Provisions) Ordinance
requires that dumping licenses be obtained by individuals or companies who
deliver public fill to public filling areas. The Civil Engineering and
Development Department (CEDD) issues the licences under delegated powers from
the Director of Lands.
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 C&D material.
Construction waste delivered to a sorting facility for disposal must contain
more than 50% by weight of inert C&D material, and construction waste
delivered to a public fill reception facility for disposal must consist
entirely of inert material.
Measures
have been introduced under Environment, Transport and Works Bureau (ETWB) TCW
No. 33/2002, “Management of Construction and Demolition
Material Including Rock” to enhance the management of construction and
demolition material, and to minimise its generation at source. The enhancement
measures include: (i) drawing up a Construction and
Demolition Material Management Plan (C&DMMP) at the feasibility study or
preliminary design stage to minimise C&D material generation and encourage
proper management of such material; and (ii) providing the contractor with
information from the C&DMMP in order to facilitate him in the preparation
of the Waste Management Plan (WMP) and to minimise C&D material generation
during construction. Projects generating C&D material less than 50,000 m3
or importing fill material less than 50,000 m3 are exempt from the
C&DMMP. The ETWB TCW No. 19/2005
“Environmental Management on Construction Sites” includes procedures on waste
management requiring contractors to reduce the C&D material to be disposed
of during the course of construction. Under ETWB TCW No. 19/2005, the
contractor is required to prepare and implement an Environmental Management
Plan (EMP) and the WMP becomes part of the EMP.
In
accordance with Section 3.4.6.1 of the EIA Study Brief, the criteria for
evaluating and assessing the waste management implications follows Annexes 7
and 15 of the EIAO-TM and the assessment covers the scope outlined in Appendix
D1 of the EIA Study Brief which includes the following:
ˇ Identify the quantity, quality and timing of
waste arising as a result of the land decontamination activities of the
Project, and based on the sequence and duration of these activities to evaluate
the potential environmental impacts that may results from these wastes.
ˇ Adopt appropriate decontamination methods to
ensure no contaminated wastes from the Project would be disposed of prior to
proper decontamination.
ˇ Prior to considering the disposal options for
various types of wastes, opportunities for reducing waste generation, on-site
or off-site re-use and recycling shall be fully evaluated.
ˇ Estimate the types and quantities of the wastes
required to be disposed of.
ˇ Identify the disposal methods / options for
each type of waste.
ˇ Identify the transportation routings and the
frequency of the trucks involved.
ˇ Identify the stockpiling areas and the disposal
outlets for the wastes.
ˇ Assess the potential impacts from the
management of solid waste with respect to potential hazards, air and odour
emissions, noise, wastewater discharges, ecology and public transport.
ˇ Identify and quantify excavation, fill
extraction, filling, sediment / mud transportation and disposal activities and
requirements.
ˇ Identify potential fill source and dumping
ground to be involved.
ˇ Identify and evaluate the best practicable
excavation methods, treatment methods, reuse / recycling options and work
programme to minimise excavation and dumping requirements and demand for fill
sources.
The ground decontamination works to be carried out for the Project would generate a variety of wastes that can be divided into distinct categories based on their composition and ultimate method of disposal. The identified waste types include:
ˇ C&D materials
ˇ Chemical waste
ˇ General refuse
The Project will not involve any excavation or dredging of marine sediment.
Each type of waste arising is described below, together with an evaluation of the potential environmental impacts associated with the handling, storage and transport of the waste. This Section assesses the waste management impact that may arise from the Project under the three different Reprovisioning Options. It is anticipated that the total amount of waste generated from the Project under the three Reprovisioning Options will be the same.
Demolition materials (Artificial Hard Material (AHM)), such as broken concrete and building debris if any, are to be generated from the site clearance works within the site area, including the concrete slab. A total of about 18,367 m3 of AHM would be generated during these works. To maximise reuse of C&D materials, on-site sorting to recover inert C&D materials would be performed as far as practicable before offsite disposal. Non-inert C&D materials would be separated from AHM, after which non-inert C&D materials would be disposed of at landfill while AHM would be disposed of at the Government Public Fill Reception Facilities (PFRFs) at Tseung Kwan O (TKO) Area 137.
The following non-inert C&D materials would also be generated during the site clearance works:
ˇ Trees and Vegetation within the site area
ˇ Steel reinforcement from site clearance of
existing features and pavement
ˇ Papers and plastics
About 58 m3 of non-inert C&D materials would be generated and 196 trees would be felled. The trees and vegetative materials are regarded as non-inert C&D waste and are considered not suitable to be transplanted as they grow in contaminated soil (Details of the landscape impact assessment will be presented in Section 10). However, other suitable materials such as the steel reinforcement which separates from the broken AHM will be recycled as far as possible, and the amount would be estimated in the WMP to be prepared by the Contractor. The remaining will be disposed of at the South East New Territories (SENT) landfill as the last resort.
The strategy for handling and disposal of the substantial amount of C&D material off-site from the works area is essential as it would impose road traffic impact and environmental impacts along the haul route to the nearby community and even affect the programme of the construction works.
No AHM will be generated during the decontamination works. As a major part of the Project, all the contaminated soil within the site area should be treated on-site. The ground decontamination method for excavated soil is proposed in the Contamination Assessment Report / Remediation Action Plan (see Appendix 7.2). About 65,479 m3 of soil not requiring decontamination would be generated during excavation works of which the Contractor should maximise the re-use during the decontamination works. Surplus soil not requiring decontamination should be designated for off-site disposal at the PFRFs and should meet the most stringent Risk-Based Remediation Goals (RBRGs) (i.e. Rural Residential / Urban Residential). It is estimated that about a maximum of 14,000 m3 soil not requiring decontamination may need to be disposed of at the PFRFs.
The operation, maintenance and servicing of plant and equipment may generate some chemical wastes such as cleansing fluids, solvents, lubrication oil, fuel, used carbon filters, and silt removed from surface runoff by desiltation. It is difficult to quantify the amount of chemical waste that will arise from the decontamination activities since it will be dependent 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, and used activated carbon filters would be small and in the order of few cubic meters per month. The amount of chemical waste to be generated will be quantified in the WMP to be prepared by the Contractor.
Chemical waste arising during the decommissioning works may pose environmental, health and safety hazards if not stored and disposed of in an appropriate manner as stipulated in the Waste Disposal (Chemical Waste) (General) Regulations. The potential hazards include:
ˇ Toxic effects to workers
ˇ Adverse impact on water quality from spills
ˇ Fire hazards
Materials classified as chemical waste will require special handling and storage arrangements before removal for appropriate treatment at the Chemical Waste Treatment Facility (CWTF) or other licensed facility. Wherever possible, opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for chemical waste are detailed in Section 6.6.4. Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements, adverse environmental impacts are not expected.
The
maximum number of workers to be employed is estimated to be 100. Based on a
generation rate of 0.65 kg per worker per day, the maximum daily arising of
general refuse during the construction period would be approximately 65 kg and
this waste can be effectively controlled by normal measures.
Opportunities to minimise C&D material
generation and maximise use of material generated as mentioned under Appendix D
(2)(i) of EIA Study Brief were considered and
reviewed during decontamination works are presented in the Sections 6.5.1 and 6.5.2 below.
Ways to minimise the
generation of C&D material
ˇ Carefully planned programme to avoid generation of additional C&D material
ˇ Provision of good practice training and adoption of site management to minimise waste generation
Ways to maximise the reuse of C&D
materials on site
ˇ Use of steel or aluminium formworks and falseworks for temporary works
ˇ Adoption of repetitive design to
maximise the reuse of formwork for temporary works
Ways to maximise the use of recycled inert C&D materials
ˇ Use of recycled inert C&D material or products with recycled aggregates for temporary or permanent works, such as concrete paving blocks, where appropriate.
Ways to maximise the
recovery rate of
materials
ˇ Provision and utilisation of on-site sorting facilities as far as practicable to maximise the recovery of inert C&D material, which can then be delivered to the PFRFs for beneficial use by other projects
ˇ Provision and utilising of
on-site sorting facilities as far as practicable to maximise the recovery of
recyclable materials (such as, steel), which can then be collected by recyclers
for recycling.
Ways to minimise the
generation of C&D material
ˇ Adoption
of most adequate decontamination method to maximise the treatment efficiency,
thus quantity of contaminated soil
can be minimised.
Ways to maximise the
reuse of treated inert C&D material on site
ˇ Maximise
the use of treated inert C&D materials for backfilling after the completion
of decontamination process.
Ways to maximise the
reuse of C&D material and/or rock on site
ˇ Use of
steel or aluminium formworks and falseworks for temporary works
ˇ Adoption of repetitive design to allow the reuse of formwork for temporary works
Ways to maximise the
recovery rate
Provision and utilisation of on-site sorting
facilities as far as practicable to maximise the recovery of recyclable
materials (such as, steel), which can then be collected by recyclers for
recycling.
The Contractor
will be required under the Contract to minimise the generation and maximise the
reuse of C&D material. Some of the requirements are summarised below:
(a) to
plan for minimising
the generation of C&D material in any temporary design, contractor’s
design, decontamination sequence and methodologies;
(b) to
submit and implement an EMP in accordance with Environment Transport and Works
Bureau Technical Circular (ETWBTC) No. 19/2005 or any succeeding circular(s),
and establish a mechanism to record the quantities of C&D materials
generated and required each month and estimate the quantities of C&D
materials that will be generated and required each year, and report to the
Project Office;
(c) to
establish a Trip-Ticket System as stipulated in DEVB TC(W) No. 6/2010 or any
superseding circular(s), for proper disposal of C&D waste to the designated
outlets;
(d) to
properly sort C&D materials into
inert C&D materials, metals, timber and other non-inert C&D waste in
the workplace to prevent cross-contamination.
Under the Waste
Disposal (Charges for Disposal of Construction Waste) Regulation, construction
waste delivered to landfill for disposal must not contain more than 50% by
weight of inert construction waste and construction waste delivered to a public
fill reception facility for disposal must consist entirely of inert
construction waste.
Adverse
impacts related to waste management such as potential hazard, air, odour, noise
wastewater discharge, ecology and public transport as mentioned in Appendix D
(2)(iv) of the Study Brief are not expected to arise, provided that good site
practices are strictly followed.
Recommendations for good site practices during the decommissioning works
include:
ˇ Nomination of an approved person, such as a
site manager, to be responsible for good site practices, arrangements for
collection and effective disposal to an appropriate facility, of all wastes
generated at the site;
ˇ Training of site personnel in proper waste
management and chemical waste handling procedures;
ˇ Provision of sufficient waste disposal points
and regular collection for disposal;
ˇ Dust suppression measures as required under the
Air Pollution Control (Construction Dust) Regulation should be followed as far
as practicable. Appropriate measures to minimise windblown litter and dust /
odour during transportation of waste by covering trucks or in enclosed containers;
ˇ Regular cleaning and maintenance programme for
drainage systems, sumps and oil interceptors;
ˇ Separation of
chemical wastes for special handling and appropriate treatment;
ˇ A recording system for amount of wastes
generated, recycled and disposed of (including the disposal sites);
ˇ General refuse shall be removed as soon as possible. As such, odour is not anticipated to be an issue to distant
sensitive receivers;
ˇ Provision of wheel washing facilities before the
trucks leaving the works area so as to minimise dust introduction from public
road;
ˇ Covers
and water spraying system should be provided for the stockpiled
C&D material to prevent
dust impact;
ˇ Provision of cover for the stockpile material, sand
bag or earth bund as barrier to prevent material from washing away and entering
the drains;
ˇ Designate
different locations for
storage of C&D material to
enhance reuse;
ˇ A well-planned programme for
transportation of C&D material should be implemented to lessen the off-site
traffic impact; and
ˇ A well-planned
delivery programme for offsite disposal and imported filling material such that
adverse noise impact from transporting of C&D material is not anticipated.
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:
ˇ Sorting of debris from
site clearance to recover reusable/ recyclable portions (i.e. soil, broken
concrete, metals etc.);
ˇ
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;
ˇ
Encourage collection of aluminium cans, PET bottles and paper by
providing separate labelled bins to enable these wastes to be segregated from
other general refuse generated by the workforce;
ˇ
Any unused chemicals or those with remaining functional capacity shall
be recycled;
ˇ
Proper storage and site practices to minimise the potential for damage
or contamination of materials;
ˇ
Plan and stock materials carefully to minimise amount of waste generated
and avoid unnecessary generation of waste; and
ˇ
Training shall be provided to workers about the concepts of site
cleanliness and appropriate waste management procedures, including waste
reduction, reuse and recycle.
In addition to the above measures, specific mitigation measures are recommended below for the identified waste arising to minimise environmental impacts during handling, transportation and disposal of these wastes.
The C&D material should be sorted on-site into inert C&D material (that is, public fill) and C&D waste. The surplus inert C&D material (e.g. surplus excavated soil not requiring decontamination as assessed in CAR/RAP in Appendix 7.2) would require disposal at the Government PFRFs in TKO Area 137 and should meet the most stringent RBRGs (i.e. Rural Residential / Urban Residential).
The C&D waste, such as steel and other
metals should be reused or recycled and, as a last resort, disposed of to
landfill. It is recommended that a suitable
area
be designated on-site
to facilitate the sorting process and a temporary stockpiling area will
be required for the separated materials.
As
discussed in Section 6.4.1.2 of
this report, the ground decontamination methods to be adopted will be proposed
in the Contamination Assessment Report / Remediation Action Plan in Section
7. It is
proposed that all treated soil be backfilled or re-used on-site.
In order to monitor the disposal of public
fill and C&D waste at PFRFs and landfills, respectively, and to control fly
tipping, a trip-ticket system as promulgated under DEVB TC(W) No. 6/2010 should be included as one of the contractual
requirements and implemented by an Environmental Team undertaking the
Environmental Monitoring and Audit work.
An Independent Environmental Checker should be responsible for auditing
the results of the system.
If chemical wastes are produced at the site, the
Contractor will be required to register with the EPD as a chemical waste
producer and to follow the guidelines stated in the Code of Practice on the
Packaging, Labelling and Storage of Chemical Wastes. Good quality containers compatible with the
chemical wastes should be used, and incompatible chemicals should be stored
separately. Appropriate labels should be securely attached on each chemical
waste container indicating the corresponding chemical characteristics of the
chemical waste, such as explosive, flammable, oxidizing, irritant, toxic,
harmful, corrosive, etc. The Contractor shall use a licensed collector to
transport and dispose of the chemical wastes, to the licensed Chemical Waste Treatment
Centre, or other licensed facilities, in accordance with the Waste Disposal
(Chemical Waste) (General) Regulation.
General
refuse should be stored in enclosed bins or compaction units separate from
C&D material. A licensed waste collector
should be employed by the contractor to remove general refuse from the site
separately. Effective collection and
storage methods (including enclosed and covered area) of site wastes should be
provided to reduce the occurrence of wind-blown light material.
With
careful planning for handling, collection and disposal of the C&D materials and with implementation of good waste
management practices, recommended mitigation measures as stated in
Section 6.6 and recommended handling and disposal
methods as
described in Table 6.1, potential hazard, air and odour emission,
noise, wastewater discharge and ecological impacts caused by handling,
collection and disposal of waste is expected to be minimal.
Table 6.1 provides a summary of the various waste
types likely to be generated during the Project together with the recommended
handling and disposal methods. On-site stockpiling area will be provided
throughout the project, and the location of the stockpiling area may be varying
within the site at different stages of land decontamination works. In case where wastes are arranged for
disposal by trucks, the trucks will be running through the major trunk roads in
Route 4 from Kennedy Town to Quarry Bay, followed by the Eastern Harbour
Crossing, Tseung Kwan O Road and Wan Po Road before
reaching the PFRFs, sorting facilities or SENT landfill located in Tseung Kwan O Area 137 for disposal. No barging point or
conveyor system will be used in the Project. The frequency of trucks for waste
disposal will not be more than 8 trucks per hour.
With
the implementation of the recommend mitigation measures for the handling,
transportation and disposal of the identified waste arising, residual impacts
are not expected for land decontamination works.
It
will be the contractor’s responsibility to ensure that all waste produced
during site clearance and decontamination works are handled, stored and
disposed of in accordance with good waste management practices and EPD’s
regulations and requirements. The
recommended mitigation measures should form the basis of the WMP to be
developed by the Contractor throughout the Project period. The WMP shall be
prepared and implemented in accordance with ETWB TC (W) No. 19/2005
Environmental Management on Construction Site.
Throughout
the project period, regular site inspection as part of the EM&A procedures
should be carried out to determine if wastes are being managed in accordance
with approved procedures and the WMP. Different aspects of waste management
including waste generation, storage, recycling, treatment, transport and
disposal would be included in the programme.
Wastes generated by the Project are likely to
include C&D material from site clearance within the Project boundary,
chemical waste from the maintenance of plant and equipment and from the
decontamination process, as well as general refuse from the workforce. Provided
that these identified waste arisings are handled,
transported and disposed of using approved methods, and that the recommended
good site practices are strictly followed, significant adverse environmental
impacts would not be expected during the Project works.
Table 6.1: Summary of Waste Handling Procedures & Disposal Routes
Waste Material Type |
Generated from Works Item |
Timing to be Generated for Each Reprovisioning Option (Approximate) |
Quantity Generated |
Quantity Reused On-site |
Quantity Disposed Off-site |
Handling |
Disposal |
||
|
|
|
A |
B |
C |
|
|
|
|
|
|
C&D material produced (Artificial Hard Materials) |
Site clearance works and Excavation works, including the concrete slab |
From 2015 to 2022, and from 2024 to 2028 |
From 2015 to 2022 |
From 2015 to 2019 |
18,367m3 |
- |
18,367m3 |
Temporary stockpile on a designated area before disposal |
To be disposed of at PFRFs for beneficial uses as last resort |
|
C&D material produced (excavated soil not requiring treatment) |
Excavation works |
From 2015 to 2022, and from 2024 to 2028 |
From 2015 to 2022 |
From 2015 to 2019 |
65,479m3 |
51,479m3 (Estimated volume only, subject to review by Contractor’s WMP) |
14,000m3 (Estimated volume only, subject to review by Contractor’s WMP) |
Temporary stockpile on a designated area on-site before backfilling. |
All excavated soil to be reused on-site as far as possible. (see Note below) Any surplus soil to be disposed of at PFRFs as last resort and should meet the most stringent RBRGs (i.e. Rural Residential / Urban Residential) |
|
Non-inert C&D waste produced |
Site clearance works |
From 2015 to 2022, and from 2024 to 2028 |
From 2015 to 2022 |
From 2015 to 2019 |
58 m3 and 196 trees |
- |
58 m3 and 196 trees |
Temporary stockpile on a designated area before disposal |
To be disposed of at a licensed landfill. |
|
Chemical waste |
Lubrication oil, fuel etc. from operation, maintenance and servicing plant and equipment |
From 2015 to 2022, and from 2024 to 2028 |
From 2015 to 2022 |
From 2015 to 2019 |
A few litres / month (preliminary estimate) |
- |
A few litres / month (preliminary estimate) |
Recycle on-site or by licensed companies. Stored on-site within suitably designed containers |
Chemical
Waste Treatment |
|
General refuse |
Waste paper, food scraps, discarded containers, etc. generated from workforce |
From 2015 to 2022, and from 2024 to 2028 |
From 2015 to 2022 |
From 2015 to 2019 |
65kg / day (preliminary estimate based on maximum workforce of 100) |
- |
65kg / day (preliminary estimate based on maximum workforce of 100) |
Provide on-site refuse collection points |
Refuse Transfer Station for compaction and containerisation to landfill |
Note: Excavated soil not requiring decontamination
from the area designated for “Public Parks/ Industrial” should only be
backfilled at the area designated for “Public Parks/ Industrial” within the
Project site.