TABLE OF CONTENTS
Page
12 Waste Management ImplicationS. 12-2
12.1 Introduction. 12-2
12.2 Environmental Legislation, Standards and Criteria. 12-2
12.3 Assessment Methodology. 12-4
12.4 Identification of Potential Waste
Sources. 12-4
12.5 Prediction & Evaluation of Environmental Impacts. 12-5
12.6 Mitigation of Adverse Environmental Impacts. 12-11
12.7 Evaluation of Residual Impacts. 12-19
12.8 Environmental Monitoring and Audit 12-19
12.9 Conclusion. 12-19
LIST OF TABLES
Table 12.1 Summary of Inert and Non-Inert
C&D Material Volumes Generated from Work Areas. 12-6
Table
12.2 Anticipated
Timing of Wastes Arising / Generation from Construction Activities and Disposal 12-6
Table
12.3 Summary
on Disposal and Reuse of Inert C&D Materials Generated. 12-8
Table
12.4 Tentative
Transportation Routings for Waste Disposal 12-14
Table
12.5 Summary
of Waste Arising, Waste Handling Procedures and Disposal Routes. 12-17
LIST OF FIGURES
60334056/EIA/12.01 Potential
Stockpile Area – Area 73
LIST OF APPENDICES
Appendix 12.01 Sludge Estimation at Relocated
Sha Tin STW in Caverns
12.1.1.1
This section identifies the
types of waste which are likely to be generated during the construction and
operation phases of the Project and related activities, and evaluates the
potential environmental impacts that may result from the waste generation.
12.1.1.2
Mitigation measures and good
site practices, including waste handling, storage and disposal, have been
recommended with reference to relevant waste legislation and management
guidelines.
12.2.1.1
The criteria and guidelines for
assessing waste management implications are outlined in Annex 7 and Annex 15 of
the EIAO-TM, respectively.
12.2.1.2
The following legislation also
covers the handling, treatment and disposal of waste in Hong Kong:
·
Waste Disposal Ordinance (WDO)(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 (Cap. 132) - Public Cleansing and Prevention of Nuisances
Regulation.
12.2.2.1
WDO prohibits any unauthorised
disposal of waste. Construction waste, defined under Cap. 354N of the WDO,
refers to a substance, matter or thing which is generated from construction
works. It includes all abandoned
materials, whether processed or stockpiled or not, before being abandoned, but
does not include sludge, screenings or matter removed or generated from
desludging, desilting or dredging works.
Under the WDO, waste can be disposed of only at designated waste
disposal facilities licensed by EPD.
12.2.3.1
Under the WDO, the Chemical
Waste (General) Regulation provides regulations for chemical waste control,
and administers the possession, storage, collection, transport and disposal of
chemical waste. EPD has also issued
the Code of Practice on the Packaging, Labelling and Storage of Chemical
Wastes (1992), which details how the chemical waste producers should comply
with the regulations on chemical waste.
12.2.4.1
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 Facilities (PFRF) for disposal must consist
entirely of inert material.
12.2.5.1
The inert portion of
Construction and Demolition (C&D) materials (including rocks, soil, broken
concrete, building debris, etc.) may be taken to public filling facilities including
public filling area, public filling barging points and stockpiling areas. These facilities usually form part of
land reclamation schemes and are operated by CEDD. The Land (Miscellaneous Provisions)
Ordinance requires that individuals or companies who deliver public fill to
the public filling facilities are required to obtain Dumping Licences. The licences are issued by CEDD under
delegated authority from the Director of Lands.
12.2.6.1
The Public Cleansing and
Prevention of Nuisances Regulation prohibits dumping of litter in public
places.
12.2.7.1
Measures have been introduced
under ETWB TCW No. 33/2002, “Management of Construction and Demolition Material
Including Rock” to enhance the management of construction and demolition
material, and to minimise its generation at source. The enhancement measures
include: (i) drawing up a Construction and Demolition Material Management Plan
(C&DMMP) at the feasibility study or preliminary design stage to minimise
C&D material generation and encourage proper management of such material;
and (ii) providing the contractor with information from the C&DMMP in order
to facilitate them in the preparation of the Waste Management Plan (WMP) and to
minimise C&D material generation during construction. Projects generating
less than 50,000 m3 of C&D material or importing less than
50,000 m3 of fill material are exempt from the C&DMMP. Further,
the C&DMMP should be prepared and submitted to Public Fill Committee (PFC)
for approval prior to commencement of the detailed design in accordance with
the ETWB TCW No. 33/2002. The C&DMMP should be vetted and endorsed by the
departmental Vetting Committee before submitting it to PFC for approval. The
ETWB TCW No. 19/2005 “Environmental Management on Construction Sites” includes
procedures on waste management requiring contractors to reduce the C&D
material to be disposed of during the course of construction. Under ETWB TCW No. 19/2005, the
contractor is required to prepare and implement an Environmental Management
Plan (EMP) and the WMP becomes part of the EMP.
12.2.8.1
The following guidelines are
also relevant to waste management in Hong Kong:
·
Code of Practice on the
Packaging, Labelling and Storage of Chemical Wastes (1992), EPD ;
·
Works Branch Technical Circular
(WBTC) No. 32/92, The Use of Tropical Hard Wood on Construction Site;
·
WBTC No. 2/93, Public Dumps;
·
WBTC No. 2/93B, Public Filling
Facilities;
·
WBTC No. 16/96, Wet Soil in
Public Dumps;
·
WBTC Nos. 25/99, 25/99A and
25/99C, Incorporation of Information on Construction and Demolition Material
Management in Public Works Subcommittee Papers;
·
WBTC No. 12/2000, Fill
Management;
·
WBTC Nos. 6/2002 and 6/2002A,
Enhanced Specification for Site Cleanliness and Tidiness;
·
WBTC No. 11/2002, Control of
Site Crusher;
·
WBTC No. 12/2002, Specification
Facilitating the Use of Recycled Aggregates;
·
DEVB TC(W) No. 6/2010, Trip Ticket System for
Disposal of Construction & Demolition Materials, Development Bureau;
·
DEVB TC(W) No. 2/2011,
Encouraging the Use of Recycled and other Green Materials in Public Works
Projects;
·
DEVB TC(W) No. 9/2011, Enhanced Control Measures for Management
of Public Fill; and
·
CEDD TC No. 03/2015, Management
of C&D Materials.
12.3
Assessment Methodology
12.3.1.1
The methodology for assessing
potential waste management impacts during the construction and operation phases
of the Project including decommissioning of existing STSTW and temporary
explosives magazine and related activities included the following tasks:
·
Estimation of types and
quantities of the wastes generated;
·
Identification of disposal
options for each type of waste;
·
Assessment of potential impacts
from the management of the waste with respect to potential hazards, air and
odour emissions, noise, wastewater discharge, ecology and public transport;
·
Evaluation of the opportunities
for reducing waste generation; and
·
Assessment of the impacts
caused by handling, collection, transportation and re-use / disposal of wastes.
12.4
Identification of Potential
Waste Sources
12.4.1.1
The construction of the Project
is tentatively scheduled to commence in early 2018 for completion in 2028. The construction activities to be
carried out for the Project include the following:
·
Construction of the caverns,
portals, tunnels, adits and ventilation shafts and associated facilities for
relocated STSTW;
·
Construction of sewage and
sludge treatment facilities and associated facilities including pipeworks and
utilities, odour control and deodorization systems, laboratories, transformer
and switchgear houses, workshops, storage, etc.;
·
Construction of water
reclamation facilities;
·
Modifications of the THEES
system in relation to effluent discharge from the relocated STSTW;
·
Construction of ancillary
facilities and temporary explosive magazine site;
·
Rehabilitation, modification
and improvement of the existing emergency submarine outfall;
·
Associated slope stabilization,
natural terrain hazard mitigation and geotechnical works;
·
Landscaping and architectural
works and amenity areas; and
·
Decommissioning and demolition
of existing STSTW and temporary explosives magazine.
12.4.1.2
The above construction
activities 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 are:
·
C&D material;
·
Chemical waste; and
·
General refuse.
12.4.1.3
Most of the C&D material
generated is hard granite, which is a valuable natural resource for
construction use. The rock produced under this project would become a local
source to support local construction industry.
12.4.1.4
There will be no dredging
/excavation of sediment for this Project.
12.4.1.5
During the operation phase of
relocated STSTW, the main waste arising would be dewatered sludge which will be
transported to the STF in Tuen Mun for treatment and disposal. A limited amount of screenings, grit,
chemical waste and general refuse would also be generated.
12.4.1.6
The rejected concentrate from
the water reclamation facilities will be collected and diverted to the drain
sump in Sludge Transfer Pumping Station.
No other waste from the plant during the operational phase of the
effluent reuse system is anticipated
12.4.1.7
During the demolition of the
existing STSTW, the public fill (mainly consisting of Artificial Hard Material
(AHM)) will be generated from the demolition of the sedimentation tanks, sludge
holding tank, sludge storage tank, sludge dewatering house, and foundation and
sub-structures of the buildings within the existing STSTW. During the demolition of the temporary
explosives magazine, public fill would be generated and they would be disposed of at the PFRF.
12.5.1
Construction Phase and Demolition of the Existing STSTW and Temporary Explosives Magazine
Construction and Demolition
(C&D) Material
12.5.1.1
C&D materials will be
generated from excavation of rock caverns (at the relocated STSTW site and the
potential explosive magazine site), tunnels, adits, ventilation/shafts
buildings, site formation works and the demolition of the existing STSTW. These C&D materials will comprise
both inert and non-inert components, such as soil, AHM, rocks, wood and
metals. Based on the latest layout,
the volume of surplus C&D materials is estimated to be approximately
6,000,000 m3 of inert material and 124,000 m3 of
non-inert material (i.e. C&D waste).
About 3,740,000 m3 of total excavated materials is rock,
which would be generated from the cavern constructions at Nui Po Shan. An estimated volume of 595,000 m3
is soft materials while 1,669,000 m3 would be AHM (i.e. concrete).
12.5.1.2
Based on the project specific
ground investigation, superficial materials mantled the cavern site are mainly
colluviums, corestone and Grade VI residual soil. The hard material in the vicinity of
cavern site is predominantly medium grained Granite. Detailed breakdown of inert &
non-inert C&D materials generated during construction phase is shown in Table 12.1.
The anticipated timing of wastes arising / generation from the construction
activities is shown in Table 12.2.
Table 12.1 Summary
of Inert and Non-Inert C&D Material Volumes Generated from Work Areas
|
Works Area
|
Volume of C&D waste (non-inert) (m3)
|
Volume of Inert C&D Material / Weights of
Inert C&D Material (Bulk Volume, m3)
|
|
|
|
Inert C&D Materials (soft public fill)
|
Inert C&D Materials (AHM)
|
Granite
|
|
|
Grade II or above
|
Grade III
|
|
|
Main Portal
|
94,072
|
204,852
|
316,406
|
-
|
50,633
|
|
|
Secondary Portal
|
28,504
|
35,156
|
-
|
4,833
|
|
|
Access Road
|
85,305
|
-
|
-
|
8,594
|
|
|
Main Access Tunnel & Secondary Access Tunnel
|
112,046
|
-
|
165,339
|
138,814
|
|
|
Caverns
|
-
|
-
|
3,317,367
|
-
|
|
|
Ventilation Adit & Ventilation Shaft
|
1,331
|
-
|
53,359
|
781
|
|
|
Emergency Outfall and Temporary
Explosives Magazine
|
61,700
|
2,297
|
-
|
-
|
|
|
Other Works at Existing STSTW
|
29,958
|
101,640
|
1,315,000
|
-
|
-
|
|
|
Total
|
124,030
|
595,378
|
1,668,859
|
3,536,065
|
203,655
|
|
Table 12.2 Anticipated
Timing of Wastes Arising / Generation from Construction Activities and Disposal
|
Works
Area
|
Proposed
Works
|
Anticipated
Timing
|
|
Main Portal
|
Site formation
|
Apr 2018 to Mar 2021
|
|
Secondary Portal
|
Site formation
|
Apr 2018 to Jul 2020
|
|
Access Road
|
Site formation
|
Apr 2018 to Mar 2020
|
|
Main Access Tunnel & Secondary Access Tunnel
|
Mechanical Excavation, Drill & Blast
|
Jul 2019 to Dec 2022
|
|
Caverns
|
Drill & Blast
|
Feb 2020 to Jan 2023
|
|
Ventilation Adit & Ventilation Shaft
|
Mechanical Excavation, Drill & Blast
|
Jun 2020 to Aug 2022
|
|
Emergency Outfall and temporary explosives magazine
|
Demolition & Pipe Jacking
|
Nov 2022 to Apr 2025
|
|
Other Works at Existing STSTW
|
Demolition
|
Jul 2027 to Jan 2029
|
12.5.1.3
There are four main sources of
works which will generate C&D materials. (1) Site formation works for
tunnel portals at A Kung Kok Street and Mui Tsz Lam Road; (2) Site formation
works for access road to the proposed surface Magazine in A Kung Kok Shan; (3)
Tunnel/Cavern construction; and (4) other works at existing STSTW.
12.5.1.4
Substantial site formation
works are required for the construction of Main Access Tunnel Portal at A Kung
Kok Street and Secondary Access Tunnel Portal at Mui Tsz Lam Road.
Predominantly soft C&D materials will be generated during the works. The inert C&D materials could be
sorted and reused as filling material within the portal area and along the
construction of access road. The surplus inert C&D material shall be
transported to Tuen Mun Area 38 Fill Bank for reuse by other projects.
12.5.1.5
Site formation works for the
access road to the proposed surface magazine is expected to be carried out
concurrently. It includes site formation works at the end of A Kung Kok Shan
Road, slope cuts, stabilization works and road work towards the hilltop along
the alignment. Part of the generated C&D materials is expected to be reused
as filling material throughout the construction of the access road. The potential stockpile area will be
located within the temporary works area Area 73 shown in Figure No. 60334056/EIA/12.01. The surplus inert C&D materials
shall be transported to Tuen Mun Area 38 Fill Bank for reuse by other
projects. An alternative disposal
site as primary outlet would be Tseung Kwan O Area 137, subject to the availability
and handling capacity of Tuen Mun Area 38 Fill Bank.
12.5.1.6
Excavation of caverns and
access tunnels will contribute to the major portion of inert C&D materials
generation. Based on the existing
Ground Investigation information obtained during the feasibility study stage,
approximately 200m of the Main Access Tunnel and 50m of Secondary Access Tunnel
will be constructed in soft ground. Inert materials (i.e soil and fracture
rock) are likely to be generated in these portions of tunnels. Excavation for the
remained portion of the tunnels and the caverns will likely generate Grade II
or better Granite which are suitable to be delivered to Lam Tei Quarry for
further processing as concrete aggregate.
Other recycling measures include process on site through crushing
facilities, recycled as backfilling material, and reuse as drainage layer and
disposal to China. There are also
some upcoming projects that may need import material. However, it is preliminarily revealed
that the peak C&D generation period of STSTW do not meet the tentative
construction programme of the upcoming projects. Nevertheless, other potential projects /
disposal outlets will continue to be explored throughout the project to
maximise the quantity of the recycled C&D materials. Exportation to China will be the last
resort should all other alternatives for C&D materials reuse in Hong Kong
becomes impractical. Detailed
breakdown on disposal and reuse of inert C&D materials generated is shown
in Table 12.3.
Table 12.3 Summary
on Disposal and Reuse of Inert C&D Materials Generated
|
Works Area
|
Off Site Disposal
|
Reuse
|
|
|
|
Soft Material (Fill, etc.)
|
AHM
|
Granite
|
Soft Material (Fill, etc.)
|
AHM
|
Granite
|
|
|
|
Grade II or above
|
Grade III
|
Grade II or above
|
Grade III
|
|
|
Volume (m3)
|
|
|
Main Portal & Pilot Adit
|
204,852
|
316,406
|
-
|
50,633
|
1,000
|
-
|
-
|
-
|
|
|
Secondary Portal
|
28,504
|
35,156
|
-
|
4,833
|
-
|
-
|
-
|
-
|
|
|
Access Road
|
66,090
|
-
|
-
|
8,594
|
18,215
|
-
|
-
|
-
|
|
|
Main Access Tunnel & Secondary Access Tunnel
|
112,046
|
-
|
165,339
|
130,619
|
-
|
-
|
-
|
8,195
|
|
|
Caverns
|
-
|
-
|
3,254,887
|
-
|
-
|
-
|
62,480
|
-
|
|
|
Ventilation Adit & Ventilation Shaft
|
1,331
|
-
|
49,086
|
781
|
-
|
-
|
4,273
|
-
|
|
|
Emergency Outfall and temporary
explosives magazine
|
32,688
|
2,297
|
-
|
-
|
29,012
|
-
|
-
|
-
|
|
|
Other Works at Existing STSTW
|
12,100
|
1,315,000
|
-
|
-
|
89,540
|
-
|
-
|
-
|
|
|
Total
|
457,611
|
1,668,859
|
3,469,312
|
195,460
|
137,767
|
0
|
66,753
|
8,195
|
|
12.5.1.7
Non-inert C&D materials
generated from the site formation works will be
recycled as far as possible before disposed to landfill.
12.5.1.8
AHM will mainly be generated
from demolition of existing STSTW.
In the cavern site, the main contributor of AHM are the demolition of
the Evangelical Lutheran Church of Hong Kong, pavement in Area 73 and cycle track,
modification works on access road to THEES portal etc.
12.5.1.9
Other works at the existing
STSTW are expected to generate AHM (such as concrete and metals) and non-inert
material. Onsite sorting shall be carried out to separate the inert and non-inert
material and transported to Tuen Mun Area 38 Fill Bank for reuse by other
projects and landfill for disposal respectively.
12.5.1.10 The potential environmental impacts arising from the handling and
disposal of the C&D material, such as air and odour emissions, noise,
wastewater discharge, ecology, potential hazard and public transport, would be
negligible. Appropriate measures
should be taken to minimise potential adverse impacts from dust during the
transportation of C&D material.
Chemical Waste
12.5.1.11 The maintenance and servicing of construction plant, equipment and
vehicles involve the use of a variety of chemicals and generate chemical
wastes. The possible chemical waste
that would be generated during the course of construction works includes:
·
Oil and grease associated with
plant maintenance;
·
Hydraulic fluid from plant
machinery;
·
Scrap batteries from vehicle
maintenance; and
·
Used paint, cleaners, solvents
used in maintaining mechanical equipment.
12.5.1.12 It is difficult to quantify the amount of chemical waste that would
arise from the construction activities since it would depend 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 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.
12.5.1.13 Building demolition may possibly generate asbestos waste as the
existing building insulation materials likely contain asbestos. Asbestos waste is categorised as
chemical waste under the Waste Disposal (Chemical Waste) Regulation. The Project Proponent should conduct an
asbestos investigation by a registered asbestos consultant prior to demolition
of existing building structure. The investigation should reveal the presence,
quantity and location of Asbestos Containing Materials (ACM). Asbestos waste
will be handled in accordance with the Code of Practice on the Handling,
Transportation and Disposal of Asbestos Waste issued by EPD. Should there be any ACM found in the
existing building structure, any demolition works of these building structures
should engage Registered Asbestos Contractors and the asbestos waste should be
collected and transported by the licensed waste collector to designated
landfill site for secure burial in accordance with the “Code of Practice on the
Handling, Transport and Disposal of Asbestos Waste” issued by the EPD. The latest designated landfill site is
West New Territories (WENT) landfill in Nim Wan, Tuen Mun to receive asbestos
waste.
12.5.1.14 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 on the workforce;
·
Adverse impacts on water
quality and aquatic biota from spills; and
·
Fire hazards.
12.5.1.15 Materials classified as chemical wastes will require special
handling and storage arrangements before removal for appropriate treatment at
the Chemical Waste Treatment Centre (CWTC) at Tsing Yi. Wherever possible opportunities should
be taken to reuse and recycle materials.
Mitigation and control requirements for chemical wastes are detailed Section 12.6.7.
Provided that the handling, storage and disposal of chemical wastes are
in accordance with these requirements and the Code of Practice on Packaging,
Labelling and Storage of Chemical Wastes published by EPD, adverse
environmental impacts are not expected to result.
General Refuse
12.5.1.16 Throughout construction, the workforce would generate refuse
comprising food scraps, waste paper, empty containers, etc. Escape of such refuse from the site
should not be allowed to occur.
12.5.1.17 The number of construction workers to be working on the Project at
any one time is estimated to be about 1000. Based on a generation rate of
0.65kg per workers per day, approximately 650 kg of general refuse will be
generated daily during the construction period. It is estimated that 1 truck per day
would be required to transport the general refuse for disposal.
12.5.1.18 Effective collection and removal of site wastes will be required to
prevent waste materials being blown around by wind, flushed or leached into the
aquatic environment, and to prevent odour nuisance. The work sites may also attract pests
and vermin if the waste storage area is not well maintained and cleaned regularly. Disposal of refuse must be at approved
waste transfer or disposal facilities.
With the implementation of good waste management practices at the site,
adverse environmental impacts would not be expected to arise from the storage,
handling and transportation of refuse.
Screenings and Grits
12.5.2.1
The screenings and grits would
be generated at the inlet works of the relocated STSTW. Screening would be compacted first and
the compacted screenings and grits will be properly stored in a covered
container and disposed of daily to WENT or North East New Territories (NENT)
landfills. The estimated volume of
screenings and grits to be generated is up to 510 m3 per month and
150 m3 per month, respectively.
It is estimated that around 51 and 15 containers per month would be
required to transport the screenings and grits separately for disposal. The
transportation and disposal of the screenings and grits are managed and
controlled by a reputable waste collector employed by the operators to reduce
the potential pest, odour and litter impacts.
Sludge
12.5.2.2
The raw sludge collected at the
sewage treatment processes of the relocated STSTW will be dewatered at the
relocated STSTW to dry solid content of 30% before disposal to EPD’s STF at
Tuen Mun. The density of sewage
sludge is subject to sludge characteristics, which may vary due to sewage
characteristic variation. Based on the typical density of primary sludge and
biological sludge, as well as the assumed primary to biological sludge ratio of
2:1, the estimated combined sludge density is 1,100 kg/m3 at 30% dry
solid content. Unlike the existing
STSTW, the sludge of the relocated STSTW will not undergo anaerobic digestions
before disposal of as the Fire Services Department has expressed that housing
of biogas production facilities inside caverns is not acceptable. In case of extreme weather condition
(e.g. typhoons), dewatered sludge will be temporary stored in cavern.
12.5.2.3
The estimated quantities of
sewage sludge to be produced by the relocated STSTW at ultimate stage is around
340 tonnes per day based on the sludge production rate of one tonne per 1,000 m3
of treated sewage and dry solid content of 30%. The estimation of sludge production is
shown in Appendix
12.01. The dewatered sludge
will be discharged into a retractable loading chute which is coupled to a
totally enclosed container to minimise odour emission. The sludge container will be hauled away
by truck when filled up and delivered to the STF for disposal. It is estimated that around 25
containers per day would be required to transport the dewatered sludge for
disposal.
12.5.2.4
Mitigation and control
requirements to minimise potential H2S / odour and water quality
impacts from sludge handling are detailed in Section 12.6.6. Provided that these mitigation measures
are properly implemented, adverse environmental impacts are not expected.
Chemical Waste
12.5.2.5
Chemical wastes such as paints,
lubricants and used batteries may be generated during maintenance
activities. This waste may pose
environmental, health and safety hazards.
Measures as stipulated in the Waste Disposal (Chemical Waste)
(General) Regulation and the Code of Practice on the Packaging,
Labelling and Storage of Chemical Wastes would be strictly followed for the
handling and disposal of chemical waste.
12.5.2.6
Should any chemical waste be
generated, the operator must register with EPD as a chemical waste
producer. The chemical waste would
be readily accepted for disposal of at the CWTC at Tsing Yi. This chemical waste should be collected
periodically in drum-type containers by licensed chemical waste collectors. With proper storage, handling and
disposal of this waste, no adverse environmental impact is anticipated.
General Refuse
12.5.2.7
During the operation phase,
general refuse would be generated by staff and office activities. This waste
includes food waste, paper, wood, plastic, office wastes etc. Plastics, papers and other recyclable wastes
should be separated from general refuse and recycled as far as possible. The remaining refuse would be collected
by licensed collectors and disposed of at landfills.
12.5.2.8
The anticipated potential
environmental impacts arisen from the handling, storage and disposal of waste
in operation phase would be insignificant provided that the mitigation measures
stated in Section 12.6.8 are strictly
followed. Therefore, it is
estimated that 1 truck per day would be required to transport the general
refuse for disposal.
12.6.1.1
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 followings 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.
12.6.1.2
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 minimisation of waste
generation in the hierarchy. EMP
and trip-ticket system are recommended for monitoring management of waste.
12.6.1.3
Different options for the
relocated STSTW have been considered and evaluated in Section 2. The options
that generate less disposal materials are considered more desirable for
minimising the potential environment impacts from waste handling and disposal.
12.6.2.1
Appropriate waste handling,
transportation and disposal methods for all waste arising generated during the
construction works for the Project should be implemented to ensure that
construction wastes do not enter the nearby streams or drainage channel.
12.6.2.2
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
activities 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
·
A WMP should be prepared and
should be submitted to the Engineer for approval. One may make reference to ETWB TCW No.
19/2005 for details.
12.6.2.3
In order to monitor the
disposal of C&D material at landfills and public filling areas, as
appropriate, and to control fly tipping, a trip-ticket system should be
included as one of the contractual requirements to be implemented by an
Environmental Team undertaking the EM&A work. One may make reference to DEVB TCW
No.6/2010 for details.
12.6.3.1
Good management and control of
construction site activities / processes can minimise 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 aluminum cans from other general refuse
generated by the work force, and to encourage collection by individual
collectors;
·
Any unused chemicals or those
with remaining functional capacity shall be recycled;
·
Maximising the use of reusable
steel formwork to reduce the amount of C&D material;
·
Prior to disposal of C&D
waste, it is recommended that wood, steel and other metals shall be separated
for re-use and / or recycling to minimise the quantity of waste to be disposed
of to landfill;
·
On-site crushing and sorting
facilities are being considered to reduce the rock size to fulfill the size
requirements from relevant waste collection / transfer / disposal facilities;
·
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 minimise 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.
12.6.3.2
In addition to the above
measures, other specific mitigation measures are recommended below to minimise
environmental impacts during handling, transportation and disposal of wastes.
12.6.4.1
Storage of materials on site
may induce adverse environmental impacts if not properly managed,
recommendations to minimise the impacts include:
·
Waste, such as soil, should be
handled and stored well to ensure secure containment, thus minimising the
potential of pollution;
·
Maintain and clean storage
areas routinely;
·
Stockpiling area should be
provided with covers as much as practicable and water spraying system to
prevent materials from wind-blown or being washed away; and
·
Different locations should be
designated to stockpile each material to enhance reuse.
12.6.4.2
Licensed waste haulers should
be employed for the collection and transportation of waste generated. The following measures should be
enforced to minimise the potential adverse impacts:
·
Remove waste in timely manner;
·
Waste collectors should only
collect wastes prescribed by their permits;
·
Impacts during transportation,
such as dust and odour, should be mitigated by the use of covered trucks or in
enclosed containers;
·
Obtain relevant waste disposal
permits from the appropriate authorities, in accordance with the WDO (Cap.
354), Waste Disposal (Charges for Disposal of Construction Waste) Regulation
(Cap. 345) and the Land (Miscellaneous Provisions) Ordinance (Cap. 28);
·
Waste should be disposed of at
licensed waste disposal facilities; and
·
Maintain records of quantities
of waste generated, recycled and disposed.
12.6.4.3
Land transport will be used for
transportation of excavated and stockpile materials. It is expected there will be 1260
vehicles per day for transporting waste during peak construction phase. The tentative transportation routings
for the disposal of various types of wastes are shown in Table
12.4. The transportation
routing may be changed subject to the traffic conditions. Nevertheless, it is anticipated that
there is no adverse impact from the waste during transportation with the
implementation of appropriated measures (e.g. using water-tight containers and
covered trucks).
Table 12.4 Tentative
Transportation Routings for Waste Disposal
|
Disposal
Outlet
|
Type
of Waste
|
Tentative
Transportation Routing
|
|
NENT Landfill
|
Non-inert C&D Materials, Screenings and Grits
and General Refuse
|
Via Tolo Highway, Fanling Highway, Man Kam To
Road and Lin Ma Hang Road
|
|
WENT Landfill
|
Non-inert C&D Materials, Screenings and Grits
and General Refuse
|
Via Tai Po Road (Sha Tin), Shing Mun Tunnel Road
(Shing Mun Tunnel), Tuen Mun Road, Lung Fu Road, Lung Mun Road and Lung Kwu
Tan Road
|
|
STF
|
Sludge
|
|
Lam Tei Rock Quarry
|
Hard Inert C&D Materials (Grade I & II
granitic rock)
|
Via Tai Po Road (Sha Tin), Shing Mun Tunnel Road
(Shing Mun Tunnel) and Tuen Mun Road
|
|
Tuen Mun Area 38 Fill Bank
|
Surplus Soft Inert C&D Materials, AHM and
Hard Inert C&D Materials (Grade III granitic rock)
|
Via Tai Po Road (Sha Tin), Shing Mun Tunnel Road
(Shing Mun Tunnel), Tuen Mun Road, Lung Fu Road and Lung Mun Road
|
|
CWTC
|
Chemical Waste
|
Via Tai Po Road (Sha Tin), Tsing Sha Highway
(Eagle’s Nest Tunnel and Stonecutters Bridge) and Tsing Yi Road
|
12.6.4.4
Alternative other than land
transport has been explored, i.e. the option of using the conveyor belt and
marine transport for transportation of excavated materials. However, this option is deemed not
preferable. First of all, the main
consideration of using the conveyor belt is to reduce the impact of land
transport on road networks, therefore the conveyor belt should be linked
directly to the pier/docking area in order to make use of marine transport
instead of land transport for the delivery of excavated materials. The nearest
pier/docking area which is suitable for loading operation is the pier in the
existing STSTW, which is quite far away from the cavern site. The route of the conveyor belt has to
span Shing Mun River Channel, which is approximately 200m wide. Extensive structural works across the
Shing Mun River Channel would be expected.
Moreover, the marine traffic route from the existing STSTW pier to Lam
Tei Quarry is long in distance and the barge have to sail across the high wind
area near Tseung Kwan O, which is not suitable for marine transport especially
during typhoon season.
12.6.4.5
In order to monitor the
disposal of C&D materials at PFRFs and landfills and to control
fly-tipping, a trip-ticket system should be established in accordance with DEVB
TCW No. 6/2010. A recording system
for the amount of waste generated, recycled and disposed, including the
disposal sites, should also be set up. Warning
signs should be put up to remind the designated disposal sites. CCTV should be installed at the vehicular entrance and exit of the site as additional measures to prevent fly-tipping.
12.6.4.6
In addition to the above
general measures, other specific mitigation measures on handling the C&D
materials and materials generated from site formation and demolition work are
recommended below, which should form the basis of the WMP to be prepared by the
Contractor in construction phase.
12.6.5.1
In order to minimise the impact
resulting from collection and transportation of C&D materials for off-site
disposal, the excavated material arising from site formation and foundation
works should be reused on-site as backfilling material and for landscaping
works as far as practicable. Other mitigation requirements are listed below:
·
A WMP, which becomes part of
the EMP, should be prepared in accordance with ETWB TCW No.19/2005;
·
A recording system for the
amount of wastes generated, recycled and disposed (including the disposal
sites) should be adopted for easy tracking; and
·
In order to monitor the
disposal of C&D materials at public filling facilities and landfills and to
control fly-tipping, a trip-ticket system should be adopted (refer to DEVB TCW
06/2010).
12.6.5.2
It is recommended that specific
areas should be provided by the Contractors for sorting and to provide temporary
storage areas (if required) for the sorted materials.
12.6.5.3
The Contactor should prepare
and implement an EMP in accordance with ETWB TCW No.19/2005, which describes
the arrangements for avoidance, reuse, recovery, recycling, storage,
collection, treatment and disposal of different categories of waste to be
generated from construction activities.
Such a management plan should incorporate site specific factors, such as
the designation of areas for segregation and temporary storage of reusable and
recyclable materials. The EMP
should be submitted to the Engineer for approval. The Contractor should implement waste
management practices in the EMP throughout the construction stage of the
Project. The EMP should be reviewed
regularly and updated by the Contractor, preferably on a monthly basis.
12.6.5.4
All surplus C&D materials
arising from or in connection with construction works should become the
property of the Contractor when it is removed unless otherwise stated. The Contractor would be responsible for
devising a system to work for on-site sorting of C&D materials and promptly
removing all sorted and process materials arising from the construction
activities to minimise temporary stockpiling on-site. The system should be
included in the EMP identifying the source of generation, estimated quantity,
arrangement for on-site sorting, collection, temporary storage areas and
frequency of collection by recycling Contractors or frequency of removal
off-site.
12.6.6.1
Through relocation of the STSTW
to caverns, the odour issue is expected to be largely reduced. Nevertheless,
the practices of good housekeeping for the relocated STSTW listed below should
be followed to further ameliorate any odour impact from handling, collection,
transportation and disposal of sludge:
·
Screens should be cleaned
regularly to remove any accumulated organic debris;
·
Grit and screening transfer
systems should be flushed regularly with water to remove organic debris and
grit;
·
Grit and screened materials
should be transferred to closed containers;
·
Scum and grease collection
wells and troughs should be emptied and flushed regularly to prevent
putrefaction of accumulated organics;
·
Skim and remove floating solids
and grease from primary clarifiers regularly;
·
Frequent sludge withdrawal from
tanks is necessary to prevent the production of gases ;
·
Sludge
should be transported to the STF by water-tight containers to avoid H2S/odour
emission and ingress of water into the containers which would lower the sludge
dryness during transportation;
·
Sludge cake should be
transferred to closed containers ;
·
Sludge containers should be
flushed with water regularly; and
·
Sludge
trucks and containers should be washed thoroughly before leaving the STSTW to
avoid any odour nuisance during transportation.
12.6.6.2
In addition, all wastewater
generated from the sludge dewatering process and all contaminated water from
the cleaning operations recommended for odour control will be diverted to the
relocated STSTW for proper treatment.
12.6.7.1
If chemical wastes are produced
at the construction site or during operation, the Contractor during
construction or the operator during operation will be required to register with
the EPD as a chemical waste producer and to follow the guidelines stated in the
Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes.
Good quality containers compatible with the chemical wastes should be used, and
incompatible chemicals should be stored separately. Appropriate labels should
be securely attached on each chemical waste container indicating the
corresponding chemical characteristics of the chemical waste, such as
explosive, flammable, oxidizing, irritant, toxic, harmful, corrosive, etc. The
Contractor shall use a licensed collector to transport and dispose of the
chemical wastes, to the licensed CWTC, or other licensed facilities, in
accordance with the Waste Disposal (Chemical Waste) (General) Regulation.
12.6.8.1
Recycling of waste paper,
aluminum cans and plastic bottles should be encouraged, it is recommended to
place clearly labelled recycling bins at designated locations which could be
accessed conveniently. Other
general refuse should be separated from chemical and industrial waste by
providing separated bins for storage to maximise the recyclable volume.
12.6.8.2
A reputable licensed waste
collector should be employed to remove general refuse on a daily basis to
minimise odour, pest and litter impacts.
12.6.8.3
Table 12.5
provides a summary of the various waste types likely to be generated during
the construction and operation phase for the Project, together with the
recommended handling and disposal methods.