8.1
Introduction
8.1.1
This waste assessment examines the quantity, quality and
timing of potential sources of solid wastes that will arise from the proposed drainage
tunnel. It identifies potential environmental impacts associated with their
handling and disposal. Options for reuse, minimization, recycling, treatment,
storage, collection, transport and disposal of such wastes are examined.
8.1.2
Where unacceptable impacts are identified, appropriate
mitigation measures and good site practice are recommended. Disposal options
will be outlined for each type of waste, and the responsibilities for disposal
or recycling discussed.
8.1.3
Types of solid wastes that arise during construction
phase include chemically inert excavated material, a relatively small quantity
of demolished material such as pipes and broken concrete, municipal waste
generated by site staff during the construction phase, and a small quantity of
chemical waste such as detergents, lubricants and engine oil for equipment
maintenance.
8.2
Environmental Legislation, Policies, Plans,
Standards and Criteria
8.2.1
The following legislation relates to the handling,
treatment and disposal of wastes in the Hong Kong SAR and will be used in
assessing potential impacts:
·
Environmental Impact Assessment Ordinance (Cap 499)
·
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
·
Dumping at Sea Ordinance (Cap 466)
8.2.2
The
following documents, circulars and guidelines which relate to waste management
and disposal in Hong Kong SAR will also be referred to during this study:
·
Technical
Memorandum on Environmental Impact Assessment Process, Annex 15 - Guidelines
for Assessment of Waste Management Implications, and Annex 7 - Criteria for
Evaluating Waste Management Implications
·
Hong
Kong Planning Standards and Guidelines (HKPSG), Chapter 9 – Environment
·
New
Disposal Arrangements for Construction Waste,
·
Code
of Practice on the Packaging, Labelling and Storage of Chemical Wastes,
·
WBTC
No. 2/93 - Public Dumps
·
WBTC
No. 2/93B - Public Filling Facilities
·
Practice
Note for Professional Persons - Construction Site Drainage (ProPECC
PN 1/94), Professional Persons Consultative Committee (1994)
·
WBTC
No. 16/96 - Wet Soil in Public Dumps
·
Waste
Reduction Framework Plan, 1998 - 2007, Planning Environment and Lands Branch,
Government Secretariat (5 November 1998)
·
WBTC
No. 4/98 - Use of Public Fill in Reclamation and Earth Filling Projects
·
WBTC
No. 4/98A - Use of Public Fill in Reclamation and Earth Filling Projects
·
WBTC
No. 25/99 - Incorporation of Information on Construction and Demolition
Material Management in Public Works Subcommittee Papers
·
WBTC
No. 25/99A - Incorporation of Information on Construction and Demolition
Material Management in Public Works Subcommittee Papers (Amendment 1)
·
WBTC
No. 25/99C - Incorporation of Information on Construction and Demolition
Material Management in Public Works Subcommittee Papers
·
WBTC
No. 19/2001 - Metallic Site Hoardings and Signboards
·
WBTC
No. 12/2000 - Fill Management
·
WBTC
No. 12/2002 - Specifications Facilitating the Use of Recycled Aggregates
·
ETWB TCW
No. 33/2002 - Management of Construction and Demolition Material including Rock.
·
ETWB
TCW No. 34/2002 - Management of Dredged/Excavated Sediment
·
ETWB
TCW No. 15/2003 - Waste Management on Construction Sites
·
ETWB
TCW No. 31/2004 - Trip-ticket System for Disposal of Construction and
Demolition Material
8.3
Assessment Methodology
8.3.1
The
methodology follows the criteria laid out in the Technical Memorandum on EIA
Process (Annexes 7 and 15). The principal legislation regulating waste is
the Waste Disposal Ordinance.
8.3.2
The
main objectives of the waste assessment are to:
(i)
identify the sources, volumes, quality and timing of
wastes arising from the construction activities;
(ii)
recommend construction waste management requirements in
terms of minimisation through project design, construction method, and site
location, identification of re-use and recycling opportunities and the
responsible party for each step of the waste management process;
(iii)
recommend disposal sites and
routes for different types of wastes unsuitable for re-use or recycling.
These recommendations
will be carried out in accordance with the current legal and administrative
requirements for waste management.
8.4
Identification of Environmental Impacts
8.4.1
Activities
during the construction phase of the proposed tunnel will result in the
generation of a variety of wastes that can be separated into 3 distinct
categories based on their nature and the options of disposal:
·
Construction
and demolition material (including excavated material)
·
Chemical
Waste
·
General
refuse
8.4.2
Handling
and disposal of these wastes may cause environmental impacts and nuisance
during the construction phase if potential impacts are not properly managed and
mitigated.
8.4.3
No
wastes are anticipated to be generated during operation except for minor
quantities of material collected during maintenance inspections.
8.5
Prediction and Evaluation of Environmental
Impacts
Introduction
8.5.1
The
main works will involve tunnelling 10.5 km length of drainage tunnel and intake
shafts formation. The main construction work and demolition will involve:
•
Site clearance and
Site formation;
•
Excavation of drainage tunnel, adits and intake shafts using tunnel boring and raise
boring machines; and
•
Construction of
tunnel portals and intake structures on top of the intake shafts.
Sources and Types of Wastes arising from this Project
8.5.2
Types
of construction and demolition material generated from the activities will be:
·
Broken
concrete and soil during site formation.
·
Granite,
volcanic rock, and soil from TBM tunnel, adits and intake
shafts during excavation.
·
Concrete
tailings, scrap steel and wooden formwork from portals and intake shaft
construction.
·
Engine
oil, lubricants, paint and detergent from construction plant maintenance.
·
Municipal
waste from construction site staff activities.
·
Slurry
produced during the construction of intakes.
Construction and
Demolition (C&D) Material
Excavated material from
tunnel
8.5.3
The
majority of excavated material will arise from constructing the drainage
tunnel, adits and intake shafts using a tunnel boring
machine (TBM) and raise boring machines (RBM). The excavated material is
largely composed of granite and volcanic rocks from both drainage tunnel
portals, with limited amount of soil.
8.5.4
The
excavation of the vertical intake shafts will mainly be carried out from the
tunnel upwards (raise boring method) and therefore, those excavated spoil will
be transported (drop down) via the intake shafts and then to either ends of
drainage tunnel. Approximate negligible amount of excavated material (1,000 m³)
will require transport on the ground surface from six (W8, W5, RR1, THR(2), WO and HR1) intake shafts only and disposed by
trucks. Estimated total quantity of spoil generated during construction at both
portals will be approximately 522,040 m³ for granite and volcanic rock
(including 1,491 m³ for soil).
8.5.5
As
most the majority of excavated material will be comprised of rocks, it is not required
for re-use on-site and will require off-site disposal either at suitable public
fill areas or designated landfills or for re-use on other construction projects
where good quality fill material is required. Estimated quantity will be 185,073
m³ at Eastern portal (Table 8.1a) which will be transported by trucks and 336,967
m³ at Western portal (Table 8.1b) which will be transported by barge respectively.
Table 8.1a Estimated Spoil Generated Breakdown from
Eastern Portal
for 24 hours TBM operation
resume
|
Eastern Portal |
Construction Period & Duration |
Total volume, m³ |
m³/month |
m³ / day by truck |
|
Bored tunnel
(Tai Hang Road to Aberdeen Tunnel) |
June 2008 to July 2010 (26 months) |
167,707 |
6,450 |
215 |
|
Adits (Granite & Volcanic Rock) |
September 2008 to April
2011 (31.5 months) |
13,741 |
436 |
15 |
|
Adits (Soil) |
- |
- |
- |
|
|
Intake Shafts
& Ventilation Pipes (Granite & Volcanic Rock) |
August 2008 to May 2011 (33.5 months) |
3,165 |
95 |
3 |
|
Intake Shafts
& Ventilation Pipes (Soils) |
460 |
14 |
0.5 |
|
|
Total |
|
185,073 |
6,995 |
233.5 |
Table 8.1b Estimated Spoil Generated Breakdown from
Western Portal
for 24 hours TBM operation resume
|
Eastern Portal |
Construction Period & Duration |
Total volume, m³ |
m³/month |
m³ / day by barge |
|
Bored tunnel
(Aberdeen Tunnel to Pok Fu Lam) |
June 2008 to August 2010 (26.5 months) |
308,674 |
11,648 |
388 |
|
Adits (Granite & Volcanic Rock) |
September 2008 to April 2011 (31 months) |
17,636 |
569 |
19 |
|
Adits (Soil) |
- |
- |
- |
|
|
Intake Shafts
& Ventilation Pipes (Granite & Volcanic Rock) |
August 2008 to June 2011 (34 months) |
9,625 |
283 |
10 |
|
Intake Shafts
& Ventilation Pipes (Soils) |
1,032 |
30 |
1 |
|
|
Total |
|
336,967 |
12,530 |
418 |
8.5.6
The contractor
should be responsible to ensure the waste is collected when appropriate by
approved licensed waste collectors and that appropriate measures are taken to
minimise adverse impacts such as dust generation. The contractor must ensure that
all necessary waste disposal permits are obtained.
8.5.7
No
potential hazard is associated with handling and disposal of excavated spoil. The
excavated spoil will be temporarily stored in stockpiles on site before final disposal.
Mitigation measures such as dampening with fine water spray and covering with
tarpaulin should be implemented. Transportation by barge will be adopted at the
western portal in part to minimise the dust, emission and noise impacts from
road transportation.
Site clearance and formation
work
8.5.8
Site
clearance works will be required, thus generating unwanted material during
construction. Construction and Demolition (C&D) material may include:
·
Topsoil;
·
Rock;
·
Waste
pipe works;
·
Wood
from formwork;
·
Material
and equipment wrappings;
·
Unusable
cement / grouting mixes; and
·
Damaged
or contaminated construction material.
8.5.9
As few
intake shafts are located on roads, little asphalt is expected. Waste of this
category is of very small quantity and mostly inert, except that the waste pipe
works could be made of metal or plastics.
8.5.10
Wood
will be used to form the concrete structure at the portals and intakes but not
inside the tunnel where the concrete panels will be made of pre-cast units. The
wood used for formwork can be reused on-site for a limited number of times
before being discarded as wastes. The reusability and quantity of final waste
depends on the shape and quality of boards. Timber which cannot be reused
should be sorted and stored separately from all inert waste before being
disposed of to landfill.
8.5.11
Reusable
steel shutters should be used as preferred alternative to formwork and falsework where possible.
8.5.12
Site
fencing may be necessary to separate the construction works from the public and
to reduce construction nuisance such as noise to nearby sensitive receivers. In
this case metal fencing or building panels to provide site fencing should be
used. Specification of the material used for noise barrier is discussed in
Noise Chapter. Timber hoarding is prohibited.
8.5.13
Sorting
is important to recover waste for reuse and recycle. The Contractor shall be
required to sort the waste materials and provide temporary storage containers
for those sorted materials such as metals, concrete, timer, plastics, glass,
excavated spoils, bricks and tiles. If area is limited, all construction wastes
should be sorted on site into inert and non-inert component. Non-inert
materials is classified as C&D waste (bamboo, timber, vegetation, packaging
waste and other organic materials) should be recycled and reused wherever
possible and disposed of to landfill only as a last resort, whilst inert
materials (debris is mainly composed of rubble (which includes concrete, cinder
block, stone, clay brick, and soil) and asphalt which are suitable for land
reclamation and site formation) should be separated and disposed of at public
filling areas operated by CEDD. Steel and other metals should be recovered from
demolition waste and recycled as far as practically possible.
8.5.14
The
total quantity of C&D material generated during the construction phase will
be dependent on the construction methods and site practices adopted, and hence
it is difficult to quantity at this stage. The amount of C&D material
expected to be generated will be quantified in the Waste Management Plan to be
prepared by contractor.
Chemical Waste
8.5.15
Where
the construction processes produce chemical waste, the contractor must register
with
·
Scrap
batteries or spent acid/alkali from their maintenance;
·
Used
engine oils, hydraulic fluids and waste fuel;
·
Spent
mineral oils/cleaning fluids from mechanical machinery; and
·
Spent solvents/solutions
from equipment cleaning activities.
8.5.16
Chemical
wastes pose serious environmental and health and safety hazards if not stored
and disposed of in an appropriate manner as outlined in the Chemical Waste
Regulations. These hazards include:
·
Toxic
effects to works;
·
Adverse
effects on water quality from spills; and
·
Fire
hazards.
8.5.17
The amount of (spent solvents, lubrication oil,
fuel and oil spill) wastes cannot be accurately predicted at this stage since
it largely depends on the contractor’s housekeeping measure. The amount is
anticipated to be small and it is recommended that the contractors should
implement good housekeeping measures to minimise the amount of waste generated.
8.5.18
The
registered chemical waste producer has to arrange for the chemical waste to be
collected by licensed collectors. Types of chemical waste likely to arise
include engine oil, lubricants, paint and some detergent from the maintenance
of construction equipment. A licensed collector shall regularly take chemical
waste to the waste treatment facility such as Chemical Waste Treatment Centre
in Tsing Yi. The quantity of this waste is limited.
These wastes cannot be reused or recycled at this or other construction site.
General Refuse
8.5.19
Solid and liquid wastes will be generated by the
construction workers during the clearance/construction period. The quantity of
municipal waste generated is estimated to be 1.39 kg/employee/day (
8.5.20
The storage of general refuse has the potential
give rise to a variety of adverse environmental impacts. These include odour if
waste is not collected frequently, windblown litter, water quality impacts if
water enters water bodies and visual impact. The refuse may attract pests and
vermin if the storage areas are not well maintained and cleaned regularly. In
addition, disposal of waste at sites other than approved waste transfer or
disposal facilities can also lead to environmental impacts.
8.5.21
Handling and disposal of general refuse should
cope with the presence of peak workforce during the construction period. Provided
that the refuse is stored and transported in accordance with proper practices
and disposed at licensed landfills, the potential environmental would be
minimal.
8.5.22
A summary of the types of solid waste expected
to arise from this Project and the proposed management strategy for each type
of waste is presented in Table 8.2.
Table 8.2 Construction Wastes
Generated by the Proposed Works
|
Area |
Major Activities |
Waste Type |
Disposal |
|
Temporary
works area at both portals and intake shafts |
Site
clearance |
Vegetation Topsoil Concrete |
Landfill Used for
landscaping Used for
landscaping |
|
Tunnel,
intake shafts, drop shafts |
Excavation |
Spoil |
Public
Filling Area or re-use as construction material |
|
Eastern
and Western Portals |
Construction
of structures |
Concrete
tailings Scrap
metal Wooden
and other non-inert waste |
Public
Filling Area Recycle Landfill |
|
All |
General
site activities |
Sewage
wastes Municipal
wastes Chemical
waste Waste Oil |
Treatment Landfill Chemical
waste treatment facilities Licensed
Contractor |
8.6
Recycling, Treatment, Storage and Disposal
Options
Construction and
Demolition Material
8.6.1
A number of measures can be introduced during
the construction period relating to a high standard of design and management
that will minimise the generation of C&D material.
8.6.2
Reusable steel or concrete panel shutters,
fencing and hoarding and signboard shall be used as a preferred alternative to
items made of wood, to minimise wastage of wood.
8.6.3
Recycling reduces the collection, transportation
and disposal of construction waste. Recycling construction on-site also assist
in reduction of import additional materials requirement.
8.6.4
Good planning and site management practice could
be employed to minimise the over ordering or mixing of concrete, mortars and
cement grouts. Proper storage and site practices will minimise the damage or
contamination of construction materials. Used bentonite
slurries should be reconditioned and reused on-site as far as possible. The
residual bentonite slurry should be mixed with dry
excavated material for disposal at the designated public filling facilities.
8.6.5
Effective
from 1 February 2005, the contractor must comply with the trip-ticket system
for the disposal of Construction and Demolition (C&D) material at public
filling facilities or landfills in order to minimise the incidence of illegal
dumping (ETWB TCW No. 31/2004).
8.6.6
Confirmation
has to be sought from Public Fill Committee (PFC) and
Chemical Wastes
8.6.7
Chemical
wastes will arise principally as a result of maintenance activities. Quantity depends
mainly on the contractor’s on-site maintenance requirement and number of plant
and vehicles utilised.
8.6.8
If the
chemical do arise from construction works, contractor should contact an
approved operator to collect the wastes for disposal such as Chemical Waste
Treatment Centre in Tsing Yi, or other facility. Chemical
Waste Regulations governing the storage and disposal of chemical wastes.
8.6.9
Suitable
containers should be used for specific types of chemical wastes, containers
should be properly label (English and Chinese in accordance with instructions
prescribed in Schedule 2 of the Regulations), resistance to corrosion, stored
safely and closely secure. Stored volume should keep not more than 450 litres
unless the specification has been approved by the
General Refuse
8.6.10
General refuse generated on-site should be
stored and collected separately from other construction and chemical wastes.
The removal of waste from the site should be arranged on a daily or at least on
every second day by the contractor to minimise any potential odour impacts,
minimise the presence of pests, vermin and other scavengers and prevent
unsightly accumulation of waste.
8.6.11
General refuse should be stored in enclosed bins
or compaction units (not suitable relatively small volumes of waste). The
recyclable component of the municipal waste generated by the activities of site
staff, such as aluminium cans, paper and cleansed plastic containers should be
separated from other municipal waste. Collection points shall be set up for
these materials and the contractor shall be responsible for arranging recycling
companies to collect these materials.
Disposal Options
8.6.12
For
this Project, there is little opportunity for reuse and recycling of excavated
rock or soil on site (estimated total quantity is around 100m³ for the
maintenance access road at both portals), since this is a tunnelling project
that requires very little fill material (mainly for construction of small
road/pavement for maintenance).
8.6.13
Excavated
material which cannot be re-used on site requires disposal to public filling
areas, reclamation or site formation projects if available and required. Disposal
excavated spoil is expected during the construction period of proposed tunnel
at 2007 to 2011. With insufficient reclamation projects in Hong Kong by the end
of 2002 to accommodate public fill, it has to temporarily stockpile the public
fill in the two fill banks for later reuse. The public filing facilities
include reclamation, barging points as transfer stations and stockpiling areas.
Existing public filling facilities available to the public are as follows:
·
Quarry
Bay and Sai Ying Pun Public Filling Barging Point
(for reclamation in Tuen Mun
Area 38)
·
Mui Wo Public Fill Stockpiling Area
·
Kai Tak Public Filling Barging Point (to fill bank in Tseung Kwan O)
·
Tseung Kwan O Area 137 Fill Bank
·
Tuen Mun Area 38 Fill Bank
8.6.14
Dumping
licences are issued by PFC to lorry owners for delivering public fill to public
filling facilities. The licences are valid to the date as specified on the
dumping licences and the licensees need to apply a new licence.
8.6.15
Any
scrap metal and plastic components of the demolition wastes shall be separated
from other wastes. The contractor shall be required to arrange for recycling
firms to collect the material. The material should only be disposed to landfill
if its quality is unsuitable for recycling. For this project, there is no
opportunity for reusing the scrap metal and plastic on site.
8.6.16
A variety of wastes which will be generated
during the construction of the proposed project, the establishment of an
efficient collection system is required to achieve environmental objectives. Table
8.3 shows the potential for re-use/ recycling and disposal option.
Table
8.3
Construction
Waste Types and Potential for Re-Use / Recycling and Disposal Options
|
Waste Type |
Works Generating Waste |
Volumes Lost as Waste |
Potential Re-Use or Recycling |
Disposal Options |
|
Spoil (Granite, Volcanic Rock and
soil) |
Tunnel and intake shafts excavation |
Most of material cannot be reused on
site |
Low quantity will be re-used for
access road. |
Majority of tunnel spoil to public
filling area or re-use on other construction sites |
|
Wood Formwork, Fencing |
Construction |
Most of the material will be degraded
after reusing for a few times |
Can be reused on site for a few times. |
Non reusable material to refuse collection
points or landfill. |
|
Reinforcing steel |
Construction of both portals and intake shafts |
Small amounts |
Most material can be reused- after cleaning Reinforcement off cuts to be scrapped/recycled. |
|
|
Chemical Waste |
Lubricants and oil from cleaning/ maintenance of
site machinery |
Small amounts |
Recycling/disposal firms will collect chemicals or
waste oil, or refill oil containers |
Chemical waste, including paints disposed of to |
|
Oil Waste |
|
|
|
Oil can be removed from recycling or soaked up by
sand for disposal to landfill. |
|
Grease trap waste |
|
|
|
Grease trap waste
collected and disposed by licensed contractor. |
|
Municipal Waste |
General site activities |
Putrecible
waste, wet paper, fabrics |
Aluminium cans, dry paper, plastic containers and
bottles |
Arrange for recycling companies to collect
recyclable material (aluminium, paper and plastics). Non recyclable material
to refuse collection points or landfill. |
Responsibilities for Construction Waste
Management
8.6.17
Upon
appointment, the main contractor of each construction contract shall be
required to submit a Waste Management Plan (WMP) which shall describe the
arrangements for avoidance, reuse, recovery and recycling, storage, collection,
treatment and disposal of different categories of waste to be generated from
the construction activities and shall take into account the recommended
mitigation measures in the EIA report. Such a management plan shall incorporate
site specific factors, such as the designation of areas for segregation and
temporary storage of reusable and recyclable materials. The WMP should be
submitted to the Engineer for approval. The contractor shall refer to the
Construction and Demolition Material Management Plan (C&DMMP) in the
Appendix F when preparing the WMP.
8.6.18
Where
waste generation is unavoidable, the potential for recycling or reuse should be
explored and opportunities taken. If wastes cannot be recycled, disposal routes
described in the WMP should be followed.
8.6.19
Training
and instruction of construction staff shall be undertaken by the contractor in
order to increase awareness of waste management issues. Requirements for staff
training should be included in the contractor’s site Waste Management Plan.
8.6.20
Training
shall be provided to workers on the concepts of the site cleanliness and
appropriate waste management procedure, including waste reduction, reuse and
recycling.
8.7
Mitigation of Adverse Environmental Impacts
Construction Phase
8.7.1
It is
proposed that the following mitigation measures be implemented during the
construction phase to minimise the potential environmental impact resulting
from the handling and disposal of construction waste:
General
8.7.2
A
proper waste management plan should be implemented to promote waste
minimisation at source. Where waste generation is unavoidable then the
potential for recycling or reuse should be explored and opportunities taken. If
wastes cannot be recycled then the recommended disposal routes should be
followed.
8.7.3
All
waste materials shall be segregated into categories covering:
·
Excavated
material or construction waste suitable for reuse on-site
·
Excavated
material or construction waste suitable for public filling areas
·
Remaining
C&D waste for landfill
·
Chemical
waste, and
·
General
refuse
8.7.4
Proper
segregation and disposal of construction waste should be implemented. Separate
containers for inert and non-inert wastes should be provided. The inert waste should
be taken to public filling area and the non-inert waste should be transported
to strategic landfills.
8.7.5
A trip-ticket
system on the solid waste transfer/disposal operations should be included as
one of the contractual requirements (ETWB TCW No. 31/2004). The Independent
Environmental Checker (IEC) will be responsible for auditing this system.
8.7.6
IEC
should also responsible for auditing the well-documented record system which
includes: (i) quantity of waste generation; (ii)
quantity of recycled; (iii) quantity of disposed; (iv)
disposal methods; and (v) sites should be implemented during
construction phase.
8.7.7
Regular
cleaning and maintenance of the waste storage area should be conducted
throughout the construction stage.
Excavated spoil
8.7.8
Control
measures for temporary stockpiled on-site should be taken in order to minimize
the noise, generation of dust, pollution of water and visual impact. Key
impacts include:
·
Surface
of stockpiled soil should be wetted with water when necessary especially during
dry season
·
Disturbance
of stockpiled soil should be minimized
·
Stockpiled
soil should be properly covered with tarpaulins especially heavy rain storms
·
Stockpiling
areas should be enclosed if possible
·
Stockpiling
location should be away from the shoreline
·
An
independent surface water drainage system equipped with silt traps should be
installed at the stockpiling area.
Chemical wastes
8.7.9
For
those processes that generate chemical waste, it may be possible to find
alternatives which generate reduced quantities or even no chemical waste, or
less dangerous types of chemical waste.
8.7.10
Construction
processes produce chemical waste, the contractor must
register with
8.7.11
The
chemical waste generated shall be properly labelled, stored and disposed of
according to the CWR. Proper storage area shall be allocated on site for
storage of chemical waste. The chemical waste should only be collected by a
licensed collector. An updated list of licensed chemical waste collector can be
obtained from
8.7.12
In
case of spillage, spill absorbent material and emulsifiers should be available
on site. This material should be replaced on a regular basis and the
contaminated material stored in a designated, secure place.
General refuse
8.7.13
A
reputable waste collector should be employed by the contractor to remove
general refuse from the site, separate from C&DM and chemical wastes, and
on regular basis in order to minimize odour, pest and litter impacts. The
burning of refuse at site is not permitted under the Air Pollution Control Ordinance
(Cap 311).
8.7.14
Office
waste can be reduced through recycling of paper if volumes are large enough to
warrant collection.
8.7.15
Good
management practices should be implemented to ensure that refuse is properly
stored and is transported for disposal of at licensed landfills.
8.8
Operation Waste
8.8.1
Although
the tunnel system is designed with minimum maintenance, accumulation of leafs,
debris and sediments inside the tunnel system is unavoidable. The volume of
waste is expected to be minimal and general cleaning will be carried out before
the onset of rainy season in each year.
The collected waste will be disposed of at designated landfill by a
reputable waste collector. .
8.9
Evaluation of Residual Impacts
8.9.1
With
the implementation of mitigation measures for handling, transportations and
disposal of identified waste arisings, the residual
impacts are expected to be minimal during the construction phase.
8.10
Environmental Audit
8.10.1
Auditing
should be carried out periodically to determine if waste is being managed in
accordance with prescribed procedures and the Waste Management Plan. The audits
should examine all aspects of waste management including waste generation,
storage, recycling, treatment, transportation, and disposal. The general site
inspections including waste management issues will be undertaken weekly by the Environmental
Team to check all construction activities for compliance with all appropriate
environmental protection and pollution control measures, including those set up
in the WMP. Meanwhile, waste management audit will be carried out on monthly
basis by the IEC. Details of waste audit are further described in Environmental
Monitoring and Audit Manual.
8.11
Conclusion
8.11.1
Waste
types and quantities have been estimated as far as possible and mitigation
measures evaluated in terms of avoidance-minimisation-recycling-disposal hierarchy
recommended by Government.
8.11.2
A large
quantity of the C&D material to be generated from the project cannot be re-used
on site. However, it is likely to be beneficially re-used in public filling
areas, reclamation or site formation sites, reuse on other construction sites, subject
to the conclusion of discussions of CEDD.
8.11.3
The contractor
shall be required to update the WMP and report the quantity, disposal method
and responsibility for handling the surplus C&D material in their
construction progress reports.
8.11.4
The
mitigation measures recommended in this section should be incorporated into
contract specifications to ensure that environmental nuisance does not arise
from the construction of proposed project. These recommendations should form
the basis of Waste Management Plan to be developed by the contractor at the construction
stage.
8.11.5
Operation
impact on the proposed route is not expected to be a key concern and no
detailed assessment will be required.