6
waste management implication
6.1.1.1
This section identifies the types of wastes that
are likely to be generated from the construction activities of the Project and
evaluates the potential environmental impacts that may result from waste
generated. It is unlikely for the operation of the Project to generate
considerable amount of waste, adverse environmental
impacts are thus not anticipated.
6.1.1.2
Mitigation measures and good site practices regarding
waste handling, storage, collection and disposal are recommended
in accordance with relevant waste legislation and guidelines. Handling and disposal
of sediments are also discussed in this section.
6.2.1
General
6.2.1.1
The criteria and guidelines for assessing waste management
implications are outlined in Annexes 7 and 15 respectively in the Technical Memorandum on Environmental Impact
Assessment (EIAO-TM).
6.2.1.2
The following legislation relates to the handling, treatment and disposal of wastes in the Hong Kong Special Administrative
Region (SAR):
·
Waste Disposal Ordinance (Cap. 354);
·
Waste Disposal (Chemical Waste)
(General) Regulation (Cap. 354C);
·
Waste Disposal (Charges for Disposal
of Construction Waste) Regulation (Cap. 354N);
·
Land (Miscellaneous Provisions)
Ordinance (Cap. 28); and
·
Public Health and Municipal Services
Ordinance Public Cleansing and Prevention Nuisances Regulation (Cap. 132BK).
Waste Disposal Ordinance
(Cap. 354)
6.2.1.3
The Waste Disposal
Ordinance (WDO) prohibits the unauthorised disposal of wastes. Construction waste is defined
under Cap. 354N of the WDO as any substance, matter or thing that is generated and
abandoned from construction works regardless if it has
been processed or stockpiled before being abandoned, excluding sludge, screenings
or any matter removed or generated from desludging, desilting or dredging works.
Under WDO, waste can be disposed of only at designated waste disposal facilities
licensed by the Environmental Protection Department (EPD).
Waste Disposal (Chemical
Waste) (General) Regulation (Cap. 354C)
6.2.1.4
Issued under the WDO, the Chemical Waste (General)
Regulation administers the possession, storage, collection, transport and disposal of chemical wastes. EPD has also issued
three guidelines detailing how the Contractor should comply with the regulations
on chemical wastes, namely A Guide to the
Chemical Waste Control Scheme (2016), A Guide to the Registration of Chemical Waste Producers (2016) and Code
of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992).
Waste Disposal (Charges for
Disposal of Construction Waste) Regulation (Cap. 354N)
6.2.1.5
Under the Waste
Disposal (Charges for Disposal of Construction Waste) Regulation, 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 (PFRF) for disposal must consist entirely of
inert material.
Land (Miscellaneous Provisions)
Ordinance (Cap. 28)
6.2.1.6
The inert portion of Construction and Demolition (C&D)
materials (including rocks, soil, broken concrete, building debris etc.) may be
taken to Public Fill Reception Facilities (PFRFs) operated by the Civil
Engineering and Development Department (CEDD). PFRFs usually form part of land reclamation
schemes. The Land (Miscellaneous Provisions)
Ordinance requires that individuals or companies who deliver public fill to
the PFRFs are required to obtain Dumping Licences. The
licences are issued by CEDD under delegated authority
from the Director of Lands.
Public Health and Municipal
Services Ordinance Public Cleansing and Prevention of Nuisances Regulation (Cap.
132BK)
6.2.1.7
The Public Cleansing
and Prevention of Nuisances Regulation provides control on illegal dumping of
wastes on unauthorised / unlicensed sites.
The illegal dumping of wastes can lead to a fine and/or imprisonment.
6.2.2
Other Relevant Environmental Guidelines
6.2.2.1
Other environmental relevant circulars/guidelines applicable
to waste management practices for this Project include:
·
Works Branch Technical Circular
(WBTC) No. 2/93 Public Dumps;
·
WBTC No. 2/93B Public Filling Facilities;
·
WBTC No. 12/2000 Fill Management;
·
ETWB TCW No. 34/2002 Management
of Dredged/Excavated Sediment;
·
ETWB TCW No. 19/2005 Environmental
Management on Construction Sites;
·
Development Bureau Technical Circular
(Works) (DevB TCW) No. 06/2010 Trip-ticket System for
Disposal of Construction and Demolition Material;
·
DevB TCW No. 08/2010 Enhanced Specification for Site Cleanliness and Tidiness;
·
DevB TCW No. 09/2011 Enhanced Control measures for Management of Public Fill;
·
Hong Kong Planning Standards and
Guidelines, 2021 (PlanD)
·
Code of Practice on the Packaging,
Labelling and Storage of Chemical Wastes (EPD);
·
A Guide to the Chemical Waste Control
Scheme (EPD); and
·
Section 4.1.3 of Chapter 4 of
the Project Administration Handbook (PAH) for Civil Engineering Works.
6.2.2.2
The WBTC No. 2/93 Public Dumps
documents the current policy related to the disposal of C&D materials.
C&D materials that are wholly inert, i.e. public fill,
should be taken to PFRFs for reuse instead of being disposed of at landfill.
6.2.2.3
Under DevB TCW No. 6/2010 Trip
Ticket System for Disposal of Construction and Demolition Materials, for all
contracts that are expected to generate inert C&D materials requiring disposal
from site, the project office shall write to the Public Fill Committee (PFC) through
Secretary of the PFC to request a designated disposal ground for incorporation into
the tender documents. For contracts where the estimated amount of non-inert C&D
materials requiring disposal at landfill facilities equals to or exceeds 50 m3,
the project office shall seek confirmation from the DEP in terms of the availability
of landfill facilities for disposal of such materials and the DEP will designate
landfill facilities, if available, for the contracts. For contracts where the estimated
amount of non-inert C&D materials to be generated from the contract is less
than 50 m3, the project office is not required to apply to DEP for designated
landfill facilities but it should still specify in the
tender documents of the appropriate landfill facilities for disposal.
6.2.2.4
Further measures have been introduced under Paragraph
4.1.3 of Chapter 4 of the PAH for Civil Engineering
Works to enhance the management of C&D materials, and to minimize its generation
at source. The enhancement measures include:
·
Drawing up a Construction and Demolition
Materials Management Plan (C&DMMP) at the feasibility study or preliminary
design stage which generates more than 50,000m3 of C&D materials
including rock or which requires imported fill in excess of 50,000m3
in order an early design stage to minimize C&D materials generation and to encourage
proper management of such materials;
·
Vetting of the C&DMMP prior
to upgrading of the project to Category A in the Public Works Programme; and
·
Providing the contractor with information
from the C&DMMP in order to facilitate the preparation
of Waste Management Plan (WMP) and to minimize C&D materials generation during
construction.
6.2.2.5
The ETWB TCW No.
19/2005 Environmental Management on Construction Sites introduces additional
measures to enhance waste management on construction sites. The circular sets out
the policies and procedures that require the contractors to prepare and implement
an Environmental Management Plan (EMP), which includes the WMP to encourage on-site
sorting of C&D materials and to minimize generation of C&D materials during the course of construction.
6.2.2.6
The ETWB TCW No. 34/2002 Management of Dredged/Excavated Sediment sets out the
procedure for seeking approval to and the management framework for marine
disposal of dredged/excavated sediment. This Practice Note outlines the
requirements to be followed in assessing and classifying the sediment and
explains the marine disposal arrangement for the classified material. The
sediment quality criteria for the classification of sediment were referred as
the Lower Chemical Exceedance Level (LCEL) and Upper Chemical Exceedance Level
(UCEL). The LCEL and UCEL are presented in Appendix A of ETWB TCW No. 34/2002.
Subject to the results of the chemical screening, biological screening may be
required to determine the disposal requirement of the sediment. There are three
types of disposal options for dredged / excavated sediments stipulated in the
ETWB TCW No. 34/2002:
·
Type 1 Open Sea Disposal or Open Sea Disposal in
Dedicated Sites;
·
Type 2 Confined Marine Disposal; and
·
Type 3 Special Treatment / Disposal.
6.2.2.7
For Type 3 disposal, the Project Proponent shall be
responsible for identifying and agreeing with the DEP the most appropriate
treatment and/or disposal arrangement.
6.3
Description of the
Environment
6.3.1.1
The
Project covers Tsuen Wan and Kwai Chung areas. The northern boundaries of the Project
are near the Tsuen Wan West Promenade while the southern boundaries of the Project
are near Kwai Tsing Interchange/Container
Port Road. The alignment comprises of elevated and at-grade
sections and is adjacent to residential, industries, schools, closed landfill
(Gin Drinkers Bay Landfill), etc.
6.4
Identification of Waste Management Implications
6.4.1
Construction Phase
6.4.1.1
Potential
waste mainly generated from the construction works of the Project. The
construction activities to be carried out for the Project include site
clearance, slope work, demolition /removal of existing facilities, excavation,
piling works, backfilling, foundation works, installation of new facilities,
road works and pavement etc. The types of waste associated with these
activities include:
·
C&D materials;
·
Excavated sediments;
·
Chemical wastes; and
·
General refuse.
6.4.2
Operation Phase
6.4.2.1
No waste is expected to be generated during the
operation of the Project.
6.5.1.1
The assessment of the potential waste management implications
during the construction phase of the Project has been conducted in accordance
with Annexes 7 and 15 of the EIAO-TM, including the following tasks:
·
Estimation of the types and quantities
of the wastes generated;
·
Evaluation of opportunities for
waste reduction and re-use;
·
Identification of disposal options
for each type of waste;
·
Assessment of potential environmental
impacts arising from waste management with respect of potential hazards, air and
odour emissions, noise, wastewater discharge, and public transport; and
·
Assessment of the impacts caused
by handling, collection, transportation and re-use
/disposal of wastes.
6.5.1.2
Prior to considering the disposal
options for various types of waste, opportunities for reducing waste generation,
on-site or off-site reuse and recycling have been evaluated. Measures which can
be taken in the construction phases for maximizing waste reduction have been separately
considered. Practices to promote segregation of waste materials
are additionally considered for advancing the waste management efficiency.
6.5.1.3
After considering all the opportunities
for reducing waste generation and maximizing reuse, the types and quantities of
the waste required to be disposed of have been estimated and the disposal options
for each type of waste have been described. The disposal method recommended for
each type of waste has taken into account the result of
the assessment. The impacts caused by handling (including stockpiling, labelling,
packaging and storage), collection and reuse / disposal
of waste have been addressed and appropriate mitigation measures have been proposed.
6.6.1
Construction Phase
Construction
and demolition (C&D) materials
6.6.1.1
C&D materials would be generated from
construction works of the Project such as site clearance, excavation/foundation
works, piling works, piercap/pier/abutment construction and slope works. The C&D materials would
comprise both inert C&D materials (i.e. public
fill including soil, rock, concrete & etc.) and non-inert C&D materials
(i.e. C&D waste including vegetation, timber, paper, plastic etc.). During
general layout design, devising construction method described in Section 2 and planning of construction programme,
considerations have been given to minimize the generation of inert C&D
materials and maximize the use of generated inert C&D materials for other
construction works.
It is confirmed that dredging works of marine sediment
would not be carried out, no dredged/ excavated sediment/mud would be generated during the
construction phase.
6.6.1.2
Based on the latest layout, it was estimated that the
total quantity of C&D materials generated would be 18,760 m3 (900 m3 of non-inert materials and 17,860 m3 of
inert materials) which will be generated during construction phase of the
Project (anticipated to commence in 2028 and be completed by 2036). However, it
should be noted that these quantities are initial estimates only and would need
to be further reviewed and updated as the design progresses.
6.6.1.3
The inert C&D materials should be reused on-site
as far practicable subject to the review at detailed design stage before
exported off site or delivered to PFRF (Tuen Mun Area
38 Fill Bank) for beneficial use in other projects with potential fill demand. The
amount of inert materials generated during the construction phase is expected to
be around 17,860 m3 and approximately 10,000m3 is
expected to be reused on-site as backfill material.
6.6.1.4
For non-inert C&D materials, upon
exhaustion of reuse/ recycling effort, they would be disposed of at landfill. The amount of non-inert materials generated during
the construction phase is expected to be around 900 m3 and
approximately 800m3 expected to be reused on-site. It is the Contractors responsibility to separate the inert and
non-inert C&D materials on site. A stockpiling area should be assigned to
facilitate the sorting of inert and non-inert C&D materials and store the
inert C&D materials for subsequent backfilling. Limited spatial area is
available within the site boundary and subject to actual on-site conditions,
land required for stockpile area would be minimized as far as possible.
6.6.1.5
A summary of the estimated quantities of C&D
materials generated from the site clearance, excavation/foundation works, slope
works and other Project construction activities together with the estimated
volumes of C&D material to be disposed to public filling area designated by
CEDD and to landfill during construction phase are presented in Table 6.1.
Table 6.1 Estimated Quantities of C&D Materials during
Construction Phase
|
Material
Type
|
Estimated Amount of C&D
Materials to be Generated (m3)
|
Total C&D Materials (m3)
|
|
Inert C&D Materials
|
Non-inert C&D Materials
|
|
C&D Materials
|
17,860
|
900
|
18,760
|
|
Reuse on Site
|
10,000
|
800
|
10,800
|
|
Deliver to Public Fills
|
7,860
|
-
|
7,860
|
|
Disposal of at Landfills
|
0
|
100
|
100
|
Note:
1. All in-situ volume
6.6.1.6
The non-inert C&D materials would be
disposed of at the West New Territories (WENT) Landfill while surplus inert C&D materials (general fill) proposed
to be transported to Tuen Mun Area 38 Fill Bank or other construction sites with potential
fill demand via the tentative transportation routing presented in Table 6.2 (disposal site of inert C&D materials is subject to the designation
by the Public Fill Committee according to DEVB TC(W) No. 6/2010). HyD shall enquire with the EPD on the availability of
landfill and acceptability of the waste. The Contractor should liaise with CEDD
on the arrangement of and obtain all necessary permits on disposal at the fill
bank. The disposal of
C&D materials would require maximum 10 trucks per day for transporting C&D materials. With the implementation of measures
recommended in Section 6.7, no adverse environmental impacts (including potential hazard, air and
odour emissions, noise and wastewater discharge and
ecology) and public transport impact caused by handling, collection, transportation and reuse/disposal of C&D materials are
expected.
Excavated
Sediments
Land
Based Sediments
6.6.1.7
Based on the existing ground investigation
(GI) information, land-based sediment is anticipated at the northern and
southern portions of the proposed widened TWR alignment. Under the Project,
there would be construction of new bridge piers for the modification of
existing TWR viaduct and new supporting columns for proposed noise enclosures
using bored pile method at these areas. Thus, it is inevitable that land-based
sediment will be involved during the piled foundation construction. The
quantities of land-based sediment to be excavated is expected to be
approximately 2,100m3. The areas with potential excavated land-based
sediment are shown in Figure 6.1, Figure 6.2, Figure 6.3 and
Figure 6.4.
6.6.1.8
In order to minimize off-site disposal, the
excavated land-based sediment is proposed to be reused on site under the
Project (e.g. as backfilling materials). The
land-based sediment would be treated using stabilization / solidification (S/S)
technique prior to reuse by mixing with cement (e.g.
Portland cement). The sediment will be provided with the necessary strength and
any contaminants in the sediment will be immobilised
in the cement/sediment mix after the S/S process. The treated materials will be
tested for the Toxicity Characteristic Leaching Procedure (TCLP) and Unconfined
Compressive Strength (UCS) and should meet the Universal Treatment Standards
(UTS) with reference to EPDs Practice Guide for Investigation and Remediation
of Contaminated Land and the UCS standard prior to reuse. If the
treated materials did not meet the UTS and UCS standards, the materials will be
re-treated and re-tested. Pilot-scale trial should be carried out before the
commencement of treatment to determine the cement/sediment ratio that could
achieve the treatment standards. Off-site sediment disposal should only be
considered as the last resort in case sediment treatment / reuse is not
possible and should follow the procedures in ETWC TCW No. 34/2002.
6.6.1.9
The estimated quantities of land-based
sediment and the proposed handling methods are summarized in Table 6.3. Sediments that meet the treatment standards are considered as
suitable for reuse on site. The recommended mitigation measures are presented
in Section
6.7. No adverse waste management implications are
anticipated with the proper implementation of the recommended mitigation
measures.
Marine-Based
Sediment
6.6.1.10
Since the Project does not involve any
construction works within the marine area, no dredged/excavated marine-based
sediment/mud would be generated during construction phase of the Project.
Chemical Waste
6.6.1.11
The maintenance and servicing
of construction plant and vehicles during construction phase of the Project
(anticipated to commence in 2028 and be completed by 2036) may generate a negligibly
small amount of chemical waste such as:
·
Used paint, engine oils, hydraulic fluids and
waste fuel from plant operation;
·
Spent mineral oils/ cleaning fluids from plant
maintenance; and
·
Spent solvents/ solutions from equipment
maintenance.
6.6.1.12
It is difficult to quantify
the amount of chemical waste that would arise from the construction activities as
it would be highly dependent on the Contractors on-site maintenance activities
and the quantity of plant and equipment utilized. It is anticipated that the quantity
of chemical waste, such as lubrication oil and solvent produced from plant maintenance,
would be small and in the order of a few cubic meters per month. The amount of chemical
waste to be generated would be quantified in the WMP to be prepared by the Contractors.
The disposal of chemical waste by licensed collector is expected to require maximum
2 trucks per month for transporting the chemical waste. With the implementation
of measures recommended in Section 6.7, no adverse environmental
impacts and public transport impact associated with handling, collection, transportation and disposal of chemical waste is expected.
6.6.1.13
Materials classified as chemical
waste shall require special handling and storage arrangements by the Contractor.
All chemical waste shall be collected by a licensed collector and be disposed at
a licensed chemical waste treatment and disposal facility such as Chemical Waste
Treatment Centre (CWTC) at Tsing Yi via the tentative
transportation routing presented in Table 6.2. Unused chemical or those with remaining functional capacity would be reused
and recycled on site or by licensed companies whenever possible. Mitigation and
control requirements for chemical wastes are detailed in Section 6.7. Provided that the handling, storage and disposal
of chemical wastes are in accordance with these requirements and that
stipulated in the Waste Disposal (Chemical Waste) (General) Regulations and the Code of Practice on Packaging, Labelling and Storage of Chemical
Wastes published by EPD, adverse environmental impacts (including potential
hazard, air and odour emissions, noise, wastewater discharge
and ecology) and public transport impact will be negligible.
General
Refuse
6.6.1.14
General refuse comprising general
site waste, such as packaging and container waste from materials and equipment used
on the site, food scraps, waste paper, empty containers
etc. would be generated by workforce during the construction phase of the
Project (anticipated to commence in 2028 and be completed by 2036). Improper collection
and removal of general refuse would give rise to hygiene problems and adverse environmental
impacts to local residents, e.g. odour
impacts, and contamination of the nearby watercourses.
6.6.1.15
The maximum number of construction
workers to be working on site at any one time was estimated to be about 100. Based
on a generation rate of 0.65kg per workers per day, approximately 65 kg of general
refuse would be generated daily during the construction period. It is expected that
the general refuse from construction sites would be disposed with the non-inert
C&D materials at WENT landfill via the tentative
transportation routing presented in Table 6.2. Given the small quantity of general refuse to be disposed of at landfill,
no adverse impact on the operation of landfill would be anticipated. The
disposal of general refuse is expected to require maximum 1 truck per day for
transporting the general refuse. With the implementation of measures
recommended in Section 6.7, no adverse environmental
impacts and public transport impact associated with handling, collection, transportation and disposal of general refuse is expected.
6.6.1.16
In order to minimize the final disposal quantities of general refuse, provision of
sufficient number of recycling bins for the collection of different types of
recyclable waste (including food waste, paper, aluminium
cans, plastic and glass bottles) and sufficient number of general refuse bins
for the collection of non-recyclable waste is recommended. The Contractor
should implement an education programme for worker
relating to avoiding, reducing, reusing and recycling
of general refuse.
6.6.1.17
The general refuse will be collected
on-site on a regular basis, separately from C&D materials by an appropriate
waste collector to be employed by the Contractor. Prior to disposal off-site, such
refuse will be temporarily put in suitably covered storage areas / bins where they
will have to be regularly cleaned and maintained to avoid attracting vermin and
pests. With proper on-site handling and storage as well as regular disposal of the
wastes, no unacceptable environmental impact would be anticipated. Recommendations
of mitigation measures for managing general refuse are presented in Section 6.7.
Transportation
Arrangement for Waste Disposal during Construction Phase
6.6.1.18
Land
transport should be used to deliver and dispose of the waste generated from the
Project area to the designated disposal outlets. Referring to Section 6.6.1.6,
it is expected there will be maximum 11 trucks per day for transporting waste
during the construction phase of the Project.
The tentative transportation routings for the disposal of various types
of wastes generated during the construction phase of the Project are presented
in Table 6.2. The transportation routings may change
subject to the actual traffic conditions of the roads. Nevertheless, with the implementation of
appropriate mitigation measures (e.g. using water-tight
containers and covered trucks), no adverse environmental impacts are expected
due to the transportation of waste.
6.6.1.19
No barging points or
conveyor systems would be established in the Project area. The C&D materials will be reused or
recycled on-site as much as practicable and any
surplus would be timely transported out of construction work area. As presented
in Section 6.6.1.4, subject to actual on-site condition, limited spatial
area is available within the Project site boundary, land required for stockpile
area would be minimized as far as possible. Details will be reviewed in design
stage, in case stockpiling areas are found required, they would be implemented
with mitigation measures such as covering the materials during heavy rainfall.
Table 6.2 Tentative Transportation Routings for Waste Disposal During Construction
Phase
|
Disposal Outlet
|
Type of Waste
|
Tentative Transportation
Routing
|
|
West New Territories Landfill
|
Non-inert C&D Materials
|
Via
Tsuen Wan Road, Tuen Mun Road, New Territories
Circular Road, Wong Chu Road, Lung Fu Road, Lung Mun Road, Lung Kwu Tan Road,
Nim Wan Road
|
|
Tuen Mun Area 38 Fill Bank
|
Surplus Inert C&D
Materials
|
Via
Tsuen Wan Road, Tuen Mun Road, New Territories
Circular Road, Wong Chu Road, Lung Fu Road, Lung Mun Road
|
|
Chemical Waste Treatment
Centre
|
Chemical Waste
|
Via
Tsuen Wan Road, Kwai Tsing Road, Tsing Yi Road
|
|
West New Territories
Landfill
|
General Refuse
|
Via
Tsuen Wan Road, Tuen Mun Road, New Territories
Circular Road, Wong Chu Road, Lung Fu Road, Lung Mun Road, Lung Kwu Tan Road,
Nim Wan Road
|
6.6.2
Operation Phase
6.6.2.1
It is expected that no
waste will be generated during the operation phase of the Project. As such it
is considered that there would be no adverse environmental impacts.
Waste
Management Hierarchy
6.7.1.1
The waste management hierarchy has been applied in the
assessment and development of mitigation measures for waste which aims at evaluating
the desirability of waste management methods and includes the following in descending
preference:
·
Avoidance and reduction of waste
generation;
·
Reuse of materials as far as practicable;
·
Recovery and recycling of residual
materials where possible; and
·
Treatment and disposal according
to relevant laws, guidelines and good practices.
6.7.1.2
Based on the waste management
hierarchy, waste reduction measures are recommended as follows to reduce impacts
and costs arisen from the Project. Recommendations of good site practices and waste
reduction measures would be stated in order to achieve
avoidance and minimization of waste generation in the hierarchy. EMP and trip-ticket
system are recommended for monitoring management of waste.
Good
Site Practices
6.7.1.3
It is anticipated that adverse impacts would not arise
on the construction site, provided that good site practices are strictly followed.
Recommendations for good site practices during the construction phase include:
·
Nomination of approved personnel,
such as a site manager, to be responsible for good site practices, and making arrangements
for collection of all wastes generated at the site and effective disposal to an
appropriate facility;
·
Training of site personnel in proper
waste management and chemical waste handling procedures;
·
Provision of sufficient waste reception/
disposal points, of a suitable vermin-proof design that minimises windblown litter;
·
Arrangement for regular collection
of waste for transport off-site and final 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 (including
the disposal sites) should be proposed; and
·
Preparation of a WMP as a part
of the EMP in accordance with ETWB TCW No. 19/2005 Environmental Management
on Construction Sites and submit to the Engineer / Architect for approval.
6.7.1.4
In order to avoid illegal dumping/fly tipping and landfilling, monitoring the disposal
of C&D material at landfills and public filling areas, as appropriate, a trip-ticket
system should be included as one of the contractual requirements to be implemented
by the Environmental Team undertaking the monitoring and auditing work. Warning signs should also be displayed to remind the designated
disposal sites. CCTV should be installed at the vehicular entrance and exit of
the site as additional measures to prevent illegal dumping/fly-tipping. One may refer to DEVB TCW No.6/2010 Trip Ticket System for
Disposal of Construction & Demolition Materials for details. Additionally, all dump trucks should be equipped with GPS
or equivalent system for the monitoring of their travel routings and parking
locations to prohibit illegal dumping and landfilling of C&D materials. A
recording system for the amount of waste generated,
recycled and disposed (including disposal sites) as well as travel routings and
parking locations should be proposed.
Waste
Reduction Measures
6.7.1.5
Good management and control of construction site activities
/ processes can minimize the generation 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:
·
Segregate and store different types
of construction related waste in different containers, skips or stockpiles to enhance
reuse or recycling of materials and their proper disposal;
·
Provide separate labelled bins to
segregate recyclable waste such as aluminium cans from other general refuse generated
by the work force, and to encourage collection by individual collectors;
·
Recycle any unused chemicals or
those with remaining functional capacity;
·
Maximise the use of reusable steel
formwork to reduce the amount of C&D material;
·
Wood, steel and other metals shall
be separated for re-use and / or recycling prior to disposal of C&D waste to
minimise the quantity of waste to be disposed of to landfill;
·
Adopt proper storage and site practices
to minimise the potential for damage to, or contamination of, construction materials;
·
Plan the delivery and stock of construction
materials carefully to minimize the amount of surplus waste generated;
·
Adopt pre-cast construction method
instead of cast-in-situ method for construction of concrete structures as much as
possible; and
·
Minimise over ordering of concrete,
mortars and cement grout by doing careful check before
ordering.
6.7.1.6
In addition to the above measures,
other specific mitigation measures are recommended below to minimize environmental
impacts during handling, transportation and disposal of
wastes.
Storage,
Collection and Transportation of Waste
6.7.1.7
Storage of materials on site may induce adverse environmental
impacts if not properly managed. The following recommendations should be
implemented to minimize the impacts:
·
Waste, such as soil, should be handled
and stored well to ensure secure containment, thus minimizing the potential of pollution;
·
Storage areas should be
maintained and cleaned routinely;
·
Stockpiling area should be provided
with covers and water spraying system to prevent materials from wind-blown or being
washed away; and
·
Different locations should be designated
to stockpile each material type to enhance reuse.
6.7.1.8
Waste collectors should be employed for the collection
and transportation of waste generated. For chemical waste, licensed waste
collector for its transportation and disposal should be employed in accordance
with the Waste Disposal
(Chemical Waste) (General) Regulation. The
following recommendations should be implemented to minimize the impacts:
·
Remove waste in a timely manner;
·
Employ trucks with cover or
enclosed containers for waste transportation;
·
Obtain relevant waste disposal
permits from the appropriate authorities;
·
Dispose of waste at licensed
waste disposal facilities; and
·
Maintain records of quantities of
waste generated, recycled and disposed.
Construction and Demolition
Material
6.7.1.9
The generated
C&D materials should be sorted on-site into inert C&D materials and
non-inert C&D waste. To minimize the impact resulting from collection and
transportation of C&D materials as far as practicable, C&D waste, such
as wood, plastic, steel and other metals should be
reused or recycled and, as a last resort, disposed to landfill. Inert C&D
materials will be recycled and reused as far as practicable. With reference to Table 6.2,
inert C&D materials are expected to be disposed to Tuen
Mun Area 38 Fill Bank. Within the stockpiling areas, the following measures
should be taken to control potential environmental impacts or nuisance:
·
Proper handling and storage of waste by means of
covers and/or water spraying system to minimize the potential environmental
impact and to prevent materials from wind-blown or being washed away;
·
Covering materials during heavy rainfall;
·
Locating stockpiles to minimize potential visual
impacts;
·
Warning signs should be displayed at the
designated disposal sites. CCTV should be installed at the vehicular entrance
and exit of the site as additional measures to prevent fly-tipping;
·
Adopting GPS or equivalent system for tracking
and monitoring of all dump trucks for the Project in recording their travel
routings and parking locations to prohibit illegal dumping and landfilling of
C&D materials; and
·
Minimizing land intake of stockpile areas as far
as possible.
Excavated
Sediments
6.7.1.10
The
sediment should be excavated, handled, treated, transported and/or disposed of
in a manner that would minimize adverse environmental impacts. In order to
minimize off-site disposal, the excavated land-based sediment is proposed to be
reused on site under the Project (e.g. as backfilling
materials). The land-based sediment would be treated using stabilization /
solidification (S/S) technique prior to reuse by mixing with cement (e.g. Portland cement). The sediment will be provided with
the necessary strength and any contaminants in the sediment will be immobilized
in the cement/sediment mix after the S/S process. The treated materials will be
tested for the Toxicity Characteristic Leaching Procedure (TCLP) and Unconfined
Compressive Strength (UCS) and should meet the Universal Treatment Standards
(UTS) with reference to EPDs Practice Guide for Investigation and Remediation of
Contaminated Land and the
UCS standard prior to reuse. If the treated materials did not meet the UTS and
UCS standards, the materials will be re-treated and re-tested. Pilot-scale
trial should be carried out before the commencement of treatment to determine
the cement/sediment ratio that could achieve the treatment standards. Off-site
sediment disposal should only be considered as the last resort in case sediment
treatment / reuse not possible and should follow the procedures in ETWB TCW
No. 34/2002.
6.7.1.11
Requirements
of the Air Pollution Ordinance (Construction Dust) Regulation, where relevant,
shall be adhered to during excavation, treatment, transportation and/or
disposal of the sediment.
6.7.1.12
Any
treatment area for the excavated sediment should be confined for carrying out
the cement S/S process and any temporary stockpiling. The area should be
designed to prevent leachate from entering the ground. Leachate, if any, should
be collected and discharged according to the Water Pollution Control Ordinance
(WPCO).
6.7.1.13
In
order to minimize the exposure to
contaminated materials, workers shall, if necessary, wear appropriate personal
protective equipment (PPE) when handling contaminated sediments. Adequate
washing and cleaning facilities shall also be provided on site.
6.7.1.14
Stockpiling
of contaminated sediments should be avoided as far as practicable. If temporary
stockpiling of contaminated sediments is necessary, the excavated sediment
should be covered by tarpaulin and the area should be placed with earth bunds
or sand bags to prevent leachate from entering the
ground, nearby drains and surrounding water bodies. The stockpiles should be
completely paved or covered by linings in order to
avoid contamination to underlying soil or groundwater. Separate and clearly
defined areas should be provided for stockpiling of contaminated and
uncontaminated materials. Leachate, if any, should be collected and discharged
according to the Water Pollution Control Ordinance (WPCO).
6.7.1.15
To
minimize the potential odour / dust emissions during
excavation and transportation of the sediment, the excavated sediments shall be
wetted during excavation / material handling and shall be properly covered when
placed on trucks or barges. Loading of the excavated sediment to the barge (if
used) shall be controlled to avoid splashing and overflowing of the sediment
slurry to the surrounding water.
6.7.1.16
Should
marine disposal of sediment by unavoidable at later stage upon exhaustion of
reuse options, separate submissions (e.g. Sediment
Sampling and Testing Plan (SSTP) and Sediment Quality Report (SQR)) shall be
submitted to EPDs Marine Dumping Control Section / Territorial Control Office
if application of dumping permit under DASO is required. The rationale for
sediment removal/disposal will also need to be submitted to the Marine Fill
Committee (MFC)/CEDD for agreement in accordance with ETWB TC(W) No. 34/2002.
Chemical
Waste
6.7.1.17
If chemical waste is produced at the construction
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. Suitable containers compatible with the
chemical waste 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 employ a licensed
collector to transport and dispose of the chemical wastes to the licensed
Chemical Waste Treatment Centre (CWTC), or other licensed facilities, in
accordance with the Waste
Disposal (Chemical Waste) (General) Regulation.
General
Refuse
6.7.1.18
General
refuse should be stored in enclosed bins or compaction units separated from
C&D materials. A reputable waste
collector should be employed by the contractor to remove general refuse from
the site. An enclosed and covered area
is preferred to reduce the occurrence of wind-blown light materials.
6.7.1.19
The
recyclable component of general refuse, such as food waste, aluminium
cans, paper and cleansed plastic containers shall be
separated from other wastes. Provision
and collection of recycling bins for different types of recyclable waste shall
be set up by the Contractor. The Contractor
shall also be responsible for arranging recycling companies to collect these
materials.
6.7.1.20
The
Contractor shall carry out an education programme for
workers in avoiding, reducing, reusing and recycling
of materials generation. Posters and
leaflets advising on the use of the bins shall also be provided in the sites as
reminders.
6.7.1.21
Table 6.3
provides a summary of the various waste types likely to be generated during the
construction works and operation of the Project, together with the recommended
handling and disposal methods.