6.1
This section identifies the
types of solid wastes that are likely to be generated during the construction
and operation phases of the Project and evaluates the potential environmental
impacts that may result from these wastes.
The main solid waste would be construction and demolition (C&D)
material generated from excavation works for the construction of TM54SPS. Mitigation measures and good site
practices, including waste handling, storage and disposal, are recommended with
reference to the applicable waste legislation and guidelines.
6.2
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.
6.3
The
following legislation relates to the handling, treatment and disposal of wastes
in the Hong Kong SAR and has been used in assessing potential impacts:
•
Waste Disposal Ordinance (Cap. 354)
•
Waste Disposal (Chemical Waste) (General) Regulation (Cap.
354)
•
Land (Miscellaneous Provisions) Ordinance (Cap. 28)
•
Public Health and Municipal Services Ordinance (Cap. 132) -
Public Cleansing and Prevention of Nuisances Regulation
6.4
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
being 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.
6.5
Under
the WDO, the Chemical Waste (General) Regulation 1992 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.
6.6
The
Public Cleansing and Prevention of Nuisances Regulation provides control on illegal
tipping of wastes on unauthorised (unlicensed) sites.
6.7
The
current policy related to the dumping of C&D material is documented in the
Works Branch Technical Circular No. 2/93, ‘Public Dumps’. Construction and demolition materials
that are wholly inert, namely 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 licences be obtained
by individuals or companies who deliver public fill to public filling
areas. The Civil Engineering &
Development Department (CEDD) issues the licences under delegated powers from
the Director of Lands.
6.8
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 public fill reception facility
for disposal must consist entirely of inert material.
6.9
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
minimize 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 minimize 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 minimize C&D material generation during
construction. Projects generating
C&D material less than
6.10
The
methodology for assessing potential waste management impacts during the
construction and operation phases of the Project included the following tasks:
•
Estimation of the types and quantities of the wastes to be
generated.
•
Assessment of potential impacts from the management of solid
waste with respect to potential hazards, air and odour emissions, noise and wastewater
discharges.
•
Identification of disposal options for each type of waste.
•
Assessment of impacts on the capacity of waste collection,
transfer and disposal facilities.
6.11
The
construction activities 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:
•
Construction and demolition (C&D) materials
•
General refuse
•
Chemical waste
6.12
Each
type of waste arising is described below, together with an evaluation of the
potential environmental impacts associated with generation, handling, storage
and transport of the waste.
6.13
Construction
and demolition (C&D) materials contain a mixture of inert and non-inert
materials. The inert C&D
material would be generated from excavation works for the foundation of TM54SPS,
it would comprise mostly soil and rock.
It is estimated that approximately 18,200m3 of materials will
be excavated. Non-inert C&D
material, i.e. C&D waste, would be generated from site formation which
would involve clearance of vegetation and wooden waste may be generated during
dismantling of formwork. The
proposed TM54SPS will consist of a superstructure and a substructure. Most of the E&M equipment will be
housed within the superstructure.
The best means to estimate the generate rate of C&D materials will
be to base the estimate on the gross floor area (GFA), approximately
6.14
The
inert C&D material should be re-used on-site as far as possible to minimize
the net amount of inert C&D material generated from the Project. However, as there would be more cut than
fill due to the excavation required for the foundation of TM54SPS, off-site
disposal of inert C&D material (approximately 18,300m3) would be
required.
6.15
Since
the construction activities would be located near the Tsing Lun Nullah,
improper management of C&D materials may introduce debris and pollutants to
the nullah, and mitigation measures including adoption of good site practices
would be required for control of impacts.
6.16
The
construction workforce would generate refuse comprising food scraps, waste
paper, empty containers, etc. Such
refuse should be properly managed so intentional or accidental release to the
surrounding environment does not occur.
Disposal of refuse at sites other than approved waste transfer or
disposal facilities shall be prohibited.
Effective collection of site wastes would be required to prevent waste
materials being blown around by wind, flushed or leached into the Tsing Lun
Nullah, or creating an odour nuisance or pest and vermin problem. Waste storage areas should be well
maintained and cleaned regularly.
With the implementation of good waste management practices at the site,
adverse environmental impacts are not expected to arise from the storage,
handling and transportation of workforce wastes.
6.17
The
maintenance and servicing of construction plant and equipment may generate some
chemical wastes such as cleaning fluids, solvents, lubrication oil and fuel. Maintenance of vehicles may also involve
the use of a variety of chemicals, oil and lubricants. It is difficult to quantify the amount
of chemical waste that will arise from the construction 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, would be small and in the order of
a few cubic metres per month. The
amount of chemical waste to be generated will be quantified in the site Waste
Management Plan to be prepared by the Contractor.
6.18
Chemical
wastes arising during the construction phase 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:
•
Toxic effects to workers
•
Adverse impacts on water quality from spills
•
Fire hazards
6.19
Materials
classified as chemical wastes will require special handling and storage
arrangements before removal for appropriate treatment at the approved Chemical
Waste Treatment Facility. Wherever
possible opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for
chemical wastes are detailed in Section 6.26. Provided that the handling, storage and
disposal of chemical wastes are in accordance with these requirements, adverse
environmental impacts are not expected to result.
6.20
Majority
of the wastes generated during operation of TM54SPS would be inlet
screenings. Raked bar screen will
be installed in the screening chamber to prevent large solid materials in
sewage from entering the pumps. Maintenance
of the raked bar screen would be carried out periodically to ensure proper
functioning of TM54SPS. The small
quantity of removed screenings will require disposal off-site to landfill.
6.21
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
activities include:
•
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
•
Training of site personnel in 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.
•
Separation of chemical wastes for special handling and
appropriate treatment at the Chemical Waste Treatment Facility.
6.22
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:
•
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.
•
A recording system for the amount of wastes generated,
recycled and disposed (including disposal sites) should be proposed.
•
Training should be provided to workers about the concepts of
site cleanliness and appropriate waste management procedures, including waste
reduction, reuse and recycle.
6.23
In
addition to the above measures, specific mitigation measures are recommended
below for the identified waste arisings to minimise environmental impacts
during handling, transportation and disposal of these wastes.
6.24
General
refuse should be stored in enclosed bins or compaction units separate from
C&D material. A reputable waste
collector should be employed by the contractor
6.25
In
order to minimise impacts resulting from collection and transportation of inert
C&D material for off-site disposal, the excavated material from the
foundation construction of TM54SPS should be reused on-site as fill material as
far as possible for general filling under the Phase 2 works for the Formation,
Roads and Drains in Tuen Mun Area 54.
The surplus excavated material should be disposed of at the designated
public fill reception facility, as agreed with the Secretary of the Public Fill
Committee, for other beneficial uses.
C&D waste generated from site clearance and dismantling of formwork
would require disposal to the designated landfill site. In order to monitor the disposal of
C&D materials at the public fill reception facility and landfill and to
control fly-tipping, a trip-ticket system should be included. One may make reference to ETWB TCW No.
31/2004 for details.
6.26
If
chemical wastes are produced at the construction site, the Contractor would 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 either the approved Chemical Waste Treatment Centre,
or another licensed facility, in accordance with the Waste Disposal (Chemical
Waste) (General) Regulation.
6.27
The
removed screenings should be properly stored in a covered container. This operation should be conducted
inside TM54SPS. The screenings would
require transportation in an enclosed vehicle for disposal to the designated landfill
site.
6.28
Table 6.1 provides a summary of the various
waste types likely to be generated during the construction and operation phases
of the Project, together with the recommended handling and disposal methods.
Table 6.1 Summary
of Waste Handling Procedures and Disposal Routes
|
Waste Material Type |
Generated from works
item |
Total Quantity
Generated |
Disposal |
Handling |
|
Construction Phase |
||||
|
Inert C&D Material i.e. public fill |
Excavation works and construction of TM54SPS (works for superstructure
and substructure) |
|
To be reused on-site as fill material as far as possible Surplus to be disposed to the designated public fill reception
facility for other beneficial uses |
Segregate C&D material to avoid contamination from other wastes |
|
C&D waste |
Site clearance and dismantling of formwork |
|
To be disposed to the designated landfill site |
|
|
General Refuse |
Waste paper, discarded containers, etc. generated from workforce |
|
Refuse station for compaction and containerisation and then to
landfill |
Provide on-site refuse collection points |
|
Chemical Waste |
Cleansing fluids, solvent, lubrication oil and fuel from construction
plant and equipment |
Few cubic metres per month (preliminary estimate) |
Chemical Waste Treatment Centre |
Recycle on-site or by licensed companies. Stored on-site within suitably designed containers |
|
Operation
Phase |
||||
|
Screenings |
Removed from raked bar screen in the screening
chamber |
|
To be disposed to the designated landfill site |
Stored in covered container |
6.29
With
the implementation of the recommended mitigation measures for the handling,
transportation and disposal of the identified waste arisings, no residual
impact is expected to arise during the construction and operation of the
Project.
6.30
Waste
management would be the contractor’s responsibility to ensure that all wastes
produced during the construction of the Project are handled, stored and
disposed of in accordance with good waste management practices and EPD’s
regulations and requirements. The
recommended mitigation measures shall form the basis of the site Waste
Management Plan to be developed by the Contractor in the construction stage.
6.31
Waste
types generated by the construction activities are likely to include C&D
materials from excavation works, site formation and dismantling of formwork,
general refuse from the workforce, and chemical waste from the maintenance of
construction plant and equipment.
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.
6.32
The
only waste generated during operation of TM54SPS would be screenings removed
from the mechanical screens in the inlet chamber. The small quantity of screenings will
require disposal off-site to landfill.