6 WASTE MANAGEMENT.. 1
6.1 Introduction. 1
6.2 Environmental
Legislation, Policies, Plans, Standards and Criteria. 1
6.3 Assessment
Methodology. 2
6.4 Identification of
Potential Sources of Impact 2
6.5 Prediction and
Evaluation of Environmental Impacts. 2
6.6 Mitigation Measures. 2
6.7 Evaluation of
Residual Impacts. 2
6.8 Environmental Audit 2
6.9 Conclusion. 2
6
WASTE management
6.1.1
This
section identifies the types of solid wastes that are likely to be generated
during the construction and operation phases of the CWB including its road
tunnel and slip roads (DP1) and evaluates the potential environmental impacts
that may result from these wastes.
The main solid waste issues would be related to construction and
demolition (C&D) material generated from demolition and excavation works. Mitigation measures and good site
practices, including measures for waste handling, storage and disposal, are
recommended with reference to the applicable waste legislation and
guidelines.
6.2.1
The
criteria and guidelines for assessing waste management implications are set out
in Annex 7 and Annex 15 of the Technical Memorandum on Environmental Impact
Assessment Ordinance (EIAO-TM), respectively.
6.2.2
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
Waste Management
6.2.3
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.
6.2.4
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.
6.2.5
The
Public Cleansing and Prevention of Nuisances Regulation provides control on
illegal tipping of wastes on unauthorised (unlicensed) sites
Chemical Waste
6.2.6
Under
the Waste Disposal (Chemical Waste) (General) Regulations, all producers of
chemical waste must register with EPD and treat their wastes, either utilising
on-site plant licensed by EPD, or arranging for a licensed collector to
transport the wastes to a licensed facility. The regulation also prescribes the
storage facilities to be provided on site, including labelling and warning
signs, and requires the preparation of written procedures and training to deal
with emergencies such as spillages, leakages or accidents arising from the
storage of chemical wastes.
Construction and Demolition (C&D) Materials
6.2.7
The
current policy related to the disposal 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.
6.2.8
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.
6.2.9
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; (ii) vetting of the C&DMMP prior to upgrading of the
project to Category A in the Public Works Programme; and (iii) providing the
contractor with information from the C&DMMP in order to facilitate 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 50,000m3 or
importing fill material less than 50,000m3 are exempt from the
C&DMMP. The new 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.
General
6.3.1
The
criteria for assessing waste management implications are outlined in Annex 7 of
the EIAO-TM. The methods for
assessing potential waste management impacts during the construction phase
follow those presented in Annex 15 of the EIAO-TM and include the following:
·
Estimation of the types and
quantities of the wastes generated.
·
Assessment of potential
impacts from the management of solid waste with respect to potential hazards,
air and odour emissions, noise, wastewater discharge and transport.
·
Assessment of impacts on the
capacity of waste collection, transfer and disposal facilities.
6.4.1
The
construction activities to be carried out for the CWB 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:
·
C&D material
·
Chemical waste
·
General refuse
6.4.2
Another
identified waste type within the project area is floating refuse. It should be noted that floating refuse
in Victoria Harbour is an existing waste and the
Project itself is not designed to generate floating refuse. Since the project
area is in the vicinity or within Victoria
Harbour, some refuse and
debris may be unintentionally brought from the site into the harbour during
heavy rains or typhoons. Nevertheless, it is considered that the quantity of
floating refuse generated from this situation would be limited.
6.4.3
Waste
arising from the operation of the Project would include waste grease from the
ventilation system of the Trunk road, and filtration cake from cleaning process
of the electrostatic precipitation system at the East Ventilation
Building. During the
operation of the ventilation system, the bearings of the ventilation fans
adopted in the ventilation system would be required to be lubricated by grease
periodically, probably once a year and hence only minimum amount of waste
grease would be generated. For the electrostatic precipitation system, less
than 10 kg per day filtration cake would be generated from the regular cleaning process. The filtration cake would be disposed of
as industrial waste.
6.4.4
Each
type of waste arising is described below, together with an evaluation of the potential
environmental impacts associated with the generation, handling, storage and
transport of the waste.
Construction and
Demolition Materials
6.5.1
Demolition
material will be generated from the removal of the IEC west-bound and
east-bound connections, with an estimated volume of approximately 0.02 Mm3
and 0.03 Mm3, respectively.
6.5.2
The
amount of C&D material expected to be generated will be quantified in the
site Waste Management Plan to be prepared by the Contractor. Since the construction activities will
be located near the waterfront, improper management of C&D materials or
spillage of slurry / grouting mixes may introduce debris and pollutants to the
harbour waters, and mitigation measures will be required (refer to Section
6.6).
6.5.3
C&D
material generated from the demolition works will be sorted on-site into public
fill (which should be re-used on-site as far as possible) and C&D waste
(which will require disposal to landfill).
Demolition material will arise from the site clearance of the highway
structures as mentioned in section 6.5.1 and will comprise primarily
concrete. It is assumed that
approximately 95% of the C&D material will be public fill and the other
will be C&D waste. It is
recommended that C&D material should be transported from the site by barge
wherever possible to reduce impacts from road transportation. The disposal of surplus public fill by
dump trunks would be considered as the last resort. It is estimated that 0.048 Mm3
from demolition of IEC will require off-site disposal to public fill reception
facilities and 0.002 Mm3 of C&D waste will require off-site
disposal to landfill. It should be noted that since the existing IEC structure that can only
be demolished at the very late stage of the Project when all of the reclamation
works have been completed, the C&D material generated from this demolition
activities could not be reused on site.
6.5.4
Excavated
materials will mainly arise from the excavation works for the CWB tunnel that
will take place upon completion of the diaphragm walls of the tunnel. The excavated material will comprise
reclamation fill material and will not contain marine sediment and could be
reused on-site as fill material for other areas of the WDII reclamation, except
those materials, including the residual bentonite slurries, arising from the
later stages of excavation works which would require off-site disposal. Considering the inert nature of the fill
material, reuse on-site would not result in any unacceptable environmental
impact. The
amount of residual used bentonite slurry requiring disposal is estimated to be
about 0.12 Mm3.
6.5.5
The
excavated material from the excavation for the tunnel box on reclaimed land
would be mainly sand fill from permanent reclamation area, of about 0.6 Mm3,
and fill material from temporary reclamation (quality CDG), of about 0.5 Mm3. Since a section of the tunnel would also
be constructed through existing land, approximately 1.27 Mm3 of
existing ground material and around 0.085 Mm3 of rock material would
also be excavated. Out of 0.6 Mm3
of sand fill excavated from permanent reclamation, around 0.2 Mm3
can be reused. Out of 0.5 Mm3
of fill material excavated from temporary reclamation, around 0.23 Mm3
can be reused. Out of 1.27 Mm3
of existing ground material, around 0.57 Mm3 can be reused. All the rock material excavated i.e.
0.085 Mm3 can also be reused.
The estimated volume of surplus excavated material likely to require
off-site disposal is approximately 1.37 Mm3. This volume arises due to excavation of
the sections of the CWB tunnel during the later stages of the project, when
filling has been completed in all the reclamation areas. There will therefore be little scope for
reuse of this excavated material on-site.
Some of this excavated material could be used in the later stages of the
Project in road abutments and landscaped areas and, depending on the detailed
construction programming, however, these quantities would be relatively small
in relation to the off-site disposal requirement noted above.
6.5.6
As
described above, the use of excavated/demolished material is maximized and the
required import of marine fill is minimized in light of the proposed
construction sequence. It should be noted that the construction sequence is
dictated by the reprovisioning arrangement for the existing waterfront
facilities along the waterfront, such as the ferry piers, cooling water
systems, salt water pumping stations, cooling water systems, salt water pumping
stations, sewage outfall, and cross habour watermains, etc. The proposed programme sequencing has
taken into account these constraints and to meet the critical project
implementation dates.
Chemical Waste
6.5.7
The maintenance and servicing
of construction plant and equipment may generate some chemical wastes such as
cleaning fluids, solvents, lubrication oil and fuel. 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.
6.5.8
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
6.5.9
Materials
classified as chemical wastes 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 wastes are detailed in
Section 6.6. Provided that the
handling, storage and disposal of chemical wastes are in accordance with these
requirements, adverse environmental impacts would not be expected to result.
General Refuse
6.5.10
The
construction workforce would generate general refuse comprising food scraps,
waste paper, empty containers, etc.
As the introduction of these wastes is likely to
have detrimental effects on water quality in the area, 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 marine environment, or creating an odour
nuisance. The waste storage area should be well maintained and cleaned
regularly so as to prevent from attracting pests and vermin to the work
sites.
6.5.11
The
maximum number of construction workers to be employed is estimated to be about
450 workers. 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 293 kg. With the implementation of waste
management practices at the site (as recommended in Section 6.6), adverse
environmental impacts would not be expected from the storage, handling and
transportation of refuse.
Floating Refuse
6.5.12 Floating
refuse in Victoria
Harbour is an existing
waste. The record of floating refuse collected by
Marine Department’s contractor within the project area is shown in Table 6.5 below. The data indicates a decreasing trend in
the quantity of floating refuse collected.
During the reporting period, approximately 31% to 42% of the refuse
within the project area was collected within the Causeway Bay Typhoon
Shelter. The quantity of floating
refuse collected was higher in the summer months which may be attributed to the
heavy rains and typhoons bringing more refuse into the harbour. In the summer, the
wind direction is from the south-west which also brings more refuse into the
harbour.
6.5.13
Floating
refuse, if not collected, may drift along the waterfront, which may create
aesthetic impact. In view of the project design, the Project itself is not
designed to generate floating refuse. Considering that the project area is in
the vicinity or within Victoria
Harbour, some refuse and
debris may be unintentionally brought from the site into the harbour during
heavy rains or typhoons. However, it is expected that the quantity of floating
refuse generated from this situation would be limited. Given that the proposed
reclamation is designed with streamlined shoreline, the potential floating
refuse problem would be minimized.
Furthermore, with the implementation of the control measures in Section
6.6, the accumulation of floating refuse within the temporary embayment formed
between the HKCEC extension and the CRIII site during construction phase would
be avoided/minimized. Since the Project would not worsen the shoreline
configuration and the implementation of appropriate control measures during
construction phase, it is considered that the future quantity of refuse to be found
along the shoreline would be similar if not better than the existing situation.
6.5.14 Specialised refuse collection
vessels currently operate in Victoria
Harbour to provide a
refuse scavenging and collection service under the responsibility of the
Pollution Control Unit of Marine Department (MD). During the construction phase, the
project proponent’s contractor will be responsible for the collection of any
refuse within their works area. With the implementation of the refuse
collection system properly within the project area, no insurmountable
environmental impact with regard to floating refuse would be anticipated during
the construction phase, or after completion of the Project.
Good Site Practices
6.6.1
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 waste handling procedures.
·
Provision of sufficient
waste disposal points and regular collection for disposal.
·
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.
·
A recording system for the
amount of wastes generated, recycled and disposed of (including the disposal
sites).
Waste Reduction Measures
6.6.2
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:
·
Sort C&D waste from
demolition of the existing waterfront structures to recover recyclable portions
such as metals.
·
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, PET bottles and paper by providing separate labelled bins to enable these
wastes to be segregated from other general refuse generated by the work force.
·
Any unused chemicals or
those with remaining functional capacity shall be recycled.
·
Use of reusable non-timber
formwork, such as in casting the tunnel box sections, to reduce the amount of
C&D material.
·
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.
6.6.3
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.
General Refuse
6.6.4
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 from C&D material.
Preferably an enclosed and covered area should be provided to reduce the
occurrence of 'wind blown' light material.
Chemical Wastes
6.6.5
After
use, chemical wastes (for example, cleaning fluids, solvents, lubrication oil
and fuel) should be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical
Wastes. Spent chemicals should
be collected by a licensed collector for disposal at the CWTF or other licensed
facility, in accordance with the Waste Disposal (Chemical Waste) (General)
Regulation.
Construction and Demolition Material
6.6.6
The
C&D material should be sorted on-site into inert C&D material (that is,
public fill) and C&D waste.
Considering that a large quantity of C&D material will be generated
from the demolition works and excavation for the tunnel construction and in
order to minimise the impact resulting from collection and transportation of
material for off-site disposal, it is recommended that the inert C&D
material should be re-used on-site in the reclamation works as far as
practicable. All the suitable
(inert) material should be broken down to 250
mm in size for reuse as public fill and surcharge in the WDII
reclamation. C&D waste, such as
wood, glass, plastic, 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 to facilitate the
sorting process and a temporary stockpiling area will be required for the
separated materials.
6.6.7
In
order to monitor the disposal of public fill and C&D waste at public
filling facilities and landfills, respectively, and to control fly tipping, a
trip-ticket system 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.
6.6.8
Bentonite
slurries used in diaphragm wall and bore-pile construction should be
reconditioned and reused wherever practicable. The disposal of residual used bentonite
slurry should follow the good practice guidelines stated in ProPECC PN 1/94
“Construction Site Drainage” and listed as follows:
·
If the disposal of a certain
residual quantity cannot be avoided, the used slurry may be disposed of at the
marine spoil grounds subject to obtaining a marine dumping licence from EPD on
a case-by-case basis.
·
If the used bentonite slurry
is intended to be disposed of through the public drainage system, it should be
treated to the respective effluent standards applicable to foul sewers, storm
drains or the receiving waters as set out in the Technical Memorandum of Standards for Effluents Discharged into
Drainage and Sewerage Systems, Inland and Coastal Waters.
·
If the used bentonite slurry
is intended to be disposed to public filling reception facilities, it will be
mixed with dry soil on site before disposal.
6.6.9
Table 6.6 provides a summary of the various
waste types likely to be generated during the construction phase, together with
the recommended handling and disposal methods.
Table 6.6 Summary of Waste Handling Procedures and
Disposal Routes
|
Waste Type
|
Generated from Works Item
|
Total Quantity Generated
|
Quantity to be disposed off-site / re-used
|
Handling
|
Disposal
|
|
C&D Material
|
Modification of IEC(1)
|
0.05 Mm3
|
0.048 Mm3 of inert C&D material (public fill) to off-site
public fill reception facilities
0.002 Mm3
of C&D waste to landfill
|
Sort on-site into :
·
Inert C&D material
(public fill)
·
C&D waste
|
Suitable material broken down to 250 mm in size for reuse as public
fill .
To be disposed to public fill reception facilities for other
beneficial uses
(approx. 0.048 Mm3)
To be disposed to landfill
(approx. 0.002 Mm3)
|
|
Excavation for CWB
tunnel box on reclaimed land & existing ground
|
0.6 Mm3 sand
fill
0.5 Mm3 selected
public fill
1.27 Mm3 existing ground material
0.085 Mm3 rock material 0.12Mm3 of bentonite
slurries
|
1.37 m3 of surplus excavated material
0.12Mm3 of
residual bentonite slurries
|
Segregate to avoid
contamination from other wastes
|
Reuse on-site as far as practicable (approx. 1.085 Mm3)
Surplus fill material to be disposed off-site (approx. 1.37 Mm3)
Residual bentonite slurries (approx 0.12Mm3)
|
|
Chemical Wastes
|
Cleansing fluids, solvent,
lubrication oil and fuel from construction plant and equipment
|
Few cubic metres
per month (preliminary estimate)
|
Few cubic metres
per month (preliminary estimate)
|
Recycle on-site or
by licensed companies
Stored on-site
within suitably designed containers
|
Chemical Waste
Treatment Facility or other licensed facility
|
|
General Refuse
|
Waste paper, discarded containers, etc. generated from workforce
|
approx. 293 kg per day (preliminary estimate based on workforce of
450)
|
approx. 293 kg per day
|
Provide on-site refuse collection points
|
Refuse station for
compaction and containerisation and then to landfill
|
Note: (1) Since the existing IEC structure that can only be demolished
at the very late stage of the Project when all of the reclamation works have
been completed, the C&D material generated from this demolition activities
could not be reused on site.
6.7.1
With
the implementation of the recommended mitigation measures for the handling,
transportation and disposal of the identified waste arisings, no adverse
residual impact is expected to arise during the construction of the proposed
Project.
6.8.1
Waste
management will 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
mitigation measures recommended in Section 6.6 should form the basis of the
site Waste Management Plan to be developed by the Contractor in the
construction stage.
6.9.1
Wastes
generated by the construction activities of the Trunk Road will include C&D
material (including excavated material and demolition material), general refuse
from the workforce and chemical waste from the maintenance of construction
plant and equipment. C&D
material with suitable characteristics would be reused on-site as far as
practicable (approximately 1.085Mm3). Surplus material would require disposal
to designed public filling facilities (approximately 1.418Mm3). By reducing the
quantity of C&D material requiring off-site disposal, the potential impacts
from the transportation of material by road will be reduced (such as noise
impacts, possible congestion due to increased traffic flows, and dust and
exhaust emissions from the haul vehicles). Provided that these identified waste arisings
are handled, transported and disposed of using approved methods and that
recommended good site practice are strictly followed, adverse environmental
impacts of air and odour emissions, noise, potential hazards, wastewater
discharge and transport would not be expected during the construction phase.
6.9.2
Floating
refuse is an existing waste and the Project itself is not designed to generate
floating refuse. Owing to the project area in close proximity to or within Victoria Harbour, limited amount of refuse and
debris may be unintentionally brought from the site into the harbour during
heavy rains or typhoons. Given that the Project would not worsen the shoreline
configuration and the implementation of appropriate control measures during
construction phase, it is considered that the future quantity of refuse to be
found along the shoreline would be similar if not better than the existing
situation.
6.9.3
With
the implementation of the refuse collection system properly within the project
area, no insurmountable environmental impact with regard to floating refuse
would be anticipated during the construction phase, or after completion of the
Project.