CONTENTS
6. WASTE MANAGEMENT AND LAND CONTAMINATION 6-2
6.1 Introduction 6-2
6.2 Relevant
Legislation, Policies, Standards and Criteria 6-2
6.3 Assessment
Methodology 6-6
6.4 Expected
Waste Sources 6-6
6.5 Waste Management
Assessment 6-7
6.6 Mitigation
Measures 6-13
6.7 Land
Contamination 6-18
6.8 Residual
Environmental Impacts 6-21
6.9 Environmental
Monitoring and Audit Requirements 6-21
6.10 Conclusion 6-22
6.1.1
This Section
identifies the potential waste arising from the construction and operation of
the Project and assesses the potential environmental impacts associated with
waste handling and disposal. The main
issues include the following:
·
Handling and disposal of construction and demolition
(C&D) materials arising from nullah revitalisation, excavation and
construction works; and
·
Management of chemical waste, general refuse and floating
refuse.
6.1.2
Waste avoidance, minimisation,
reuse and recycling, storage, collection, transport and disposal schemes have
been examined and appropriate measures for waste reduction and management have
been proposed.
6.1.3
This Section also
identifies and assesses any potential land contamination issues arising from
the Project and to propose remediation measures if necessary.
6.2.1
The following discussion on legislative requirements and
evaluation criteria applies to both the construction and operation phases of
the Project. The criteria and guidelines
for evaluating potential waste management implications are laid out in Annexes
7 and 15 of the EIAO-TM under the EIAO (Cap 499). The following legislation covers, or has some
bearing upon the handling, treatment and disposal of the wastes generated from
the construction and operation of the Project.
·
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);
·
Public Health and
Municipal Services Ordinance (Cap.132) – Public Cleansing and Prevention of
Nuisances Regulation; and
·
Dumping at Sea
Ordinance (Cap 466).
Waste Disposal Ordinance (Cap 354)
6.2.2
The Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal of wastes, with waste defined as any
substance or article, which is abandoned. Construction waste is defined as any
substance, matter or thing that is generated from construction work and
abandoned, whether or not it has been processed or stockpiled before being
abandoned, but does not include any sludge, screenings or matter removed in or
generated from any desludging, desilting or dredging works.
6.2.3
Under the WDO, wastes can only be disposed of at a licensed
site. It should be noted that under the WDO, the authority may by license
permit any person to provide services for the collection or removal of chemical
waste or clinical waste but not for general refuse. In addition, the Land
(Miscellaneous Provisions) Ordinance (Cap 28) requires that individuals or
company who deliver public fill to the public fill reception facilities to
obtain Dumping Licenses. For general waste there is no charge and this will
need to be disposed of in a licensed facility.
Waste Disposal (Chemical Waste) (General) Regulation (Cap
354C)
6.2.4
Chemical waste as defined under the Waste Disposal
(Chemical Waste) (General) Regulation includes any substance being scrap
material, or unwanted substances specified under Schedule 1 of the Regulation,
if the specified substance or chemical occurs in such a form, quantity or
concentration so as to cause pollution or constitute a danger to health or risk
of pollution to the environment.
6.2.5
A person should not produce, or cause to be produced,
chemical wastes without registration with the Environmental Protection
Department (EPD). Chemical wastes must
either be treated using on-site facility licensed by EPD or be collected by a
licensed collector for off-site treatment at a licensed facility. Under EPD Regulation, the waste producer,
collector and disposal facility must sign all relevant parts of a computerised trip ticket for each consignment of
waste. The computerized system is
designed to allow the transfer of wastes to be traced from cradle-to-grave.
6.2.6
The EPD Regulation prescribes storage facilities to be
provided on-site which include labelling and warning signs. To reduce the risks of pollution and danger
to human health or life, the waste producer is required to prepare and make
available written emergency procedures for spillage, leakage or accidents
arising from the storage of chemical wastes.
They must also provide their employees with training on such procedures.
Waste Disposal (Charges for Disposal of Construction Waste)
Regulation (Cap 354N)
6.2.7
The Waste Disposal (Charges for Disposal of Construction
Waste) Regulation defined construction waste as any substance, matters or
things that is generated from construction work and abandoned, whether or not
it has been processed or stockpiled before being abandoned. It does not include any sludge, screening or
matter removed in or generated from any desludging, desilting or dredging
works.
6.2.8
The Construction Waste Disposal Charging Scheme entered
into operation on 1 December 2005.
Starting from 1 December 2005, the main contractor who undertakes
construction work under a contract with value of HK$1 million or above is
required to open a billing account solely for the contract for waste
disposal. Application shall be made
within 21 days after the contract is awarded.
6.2.9
Depending on the percentage of inert materials in the
construction waste, inert construction waste can be disposed of at public fill
reception facilities. However, mixed
construction waste can be disposed of at construction waste sorting facilities,
landfills and Outlying Islands Transfer Facilities which have different
disposal costs. The scheme encourages
reducing, reusing and sorting of construction waste such that the waste
producer can reduce their disposal fee. Table
6.1
summarises the government construction waste disposal
facilities, types of waste accepted and disposal cost.
Table 6.1 Government Facilities for Disposal of
C&D Materials
|
Government Waste Disposal Facilities
|
Type
of Construction Waste Accepted
|
Charge
(HK$/Tonne)
|
|
Public fill reception facilities
|
Consisting entirely of
inert construction waste++
|
$71
|
|
Sorting facilities
|
Containing more than 50% by weight of
inert construction waste++
|
$175
|
|
Landfills@
|
Containing not more than 50% by weight
of inert construction waste++
|
$200
|
|
Transfer Facilities@
|
Containing any percentage of
inert construction waste++
|
$200
|
|
# Except for the Outlying Islands
Transfer Facilities, the minimum charge load is 1 tonne, i.e. if a load of
waste weighs 1 tonne or less, it will be charged as 1 tonne. A load of waste
weighing more than 1 tonne will be charged at 0.1 tonne increment. For
Outlying Islands Transfer Facilities, the charge is $20 per 0.1 tonne and the
minimum charge load is 0.1 tonne.
++ Inert construction waste means rock,
rubble, boulder, earth, soil, sand, concrete, asphalt, brick, tile, masonry
or used bentonite.
@ If a load of waste contains construction
waste and other waste, that load will be regarded as consisting entirely of
construction waste for the purpose of calculating the applicable charge.
|
Land (Miscellaneous Provisions) Ordinance (Cap 28)
6.2.10
The inert portion of C&D materials (also called public
fill) may be taken to public fill reception facilities. Public fill reception facilities usually form
part of land reclamation schemes and are operated by the Civil Engineering and
Development Department (CEDD) and others.
The Land (Miscellaneous Provisions) Ordinance requires that individuals
or companies who deliver public fill to the public fill reception facilities to
obtain Dumping Licences. The licences are
issued by CEDD under delegated authority from the Director of Lands.
6.2.11
Individual licences and
windscreen stickers are issued for each vehicle involved. Under the licence
conditions, public fill reception facilities will only accept earth, soil,
sand, rubble, brick, tile, rock, boulder, concrete, asphalt, masonry or used
bentonite. In addition, in accordance
with paragraph 11 of DEVB TC(W) No. 6/2010 “Trip Ticket System for
Disposal of Construction and Demolition Materials”, the Public Fill Committee
will advise on the acceptance criteria (e.g. no mixing of construction waste,
nominal size of the materials less than 250mm, etc). The material will, however, be free from
marine mud, household refuse, plastic, metal, industrial and chemical wastes,
animal and vegetable matter and any other materials considered unsuitable by
the public fill reception facility supervisor.
Public Health and Municipal Services Ordinance (Cap 132) –
Public Cleansing and Prevention of Nuisances Regulation
6.2.12
This Regulation provides a further control on the illegal
dumping of wastes on unauthorised (unlicensed) sites.
Dumping at Sea Ordinance (Cap 466)
6.2.13
The Dumping at Sea Ordinance (DASO) is to control the
disposal of substances and articles at sea and the dumping of substances and
articles in the sea and under the sea-bed, and for connected purposes. All
these operations would require a permit to be issued by the Director of
Environmental Protection (DEP) as the Authority under the DASO. Before an application of a marine dumping
permit is made, requirements stipulated in ETWB TC(W) No. 34/2002 regarding the
sampling, testing and disposal arrangement of dredged/excavated sediments must
be fulfilled.
Other Relevant Guidance
6.2.14
Other guideline documents which detail how the Contractor
will comply with the WDO and its associated regulations include:
·
Waste Disposal Plan
for Hong Kong (December 1989), Planning, Environment and Lands Branch
Government Secretariat, Hong Kong Government;
·
Chapter 9 -
Environment (1999), Hong Kong Planning Standards and Guidelines, Hong Kong
Government;
·
New Disposal
Arrangements for Construction Waste (1992), EPD & CED, Hong Kong SAR
Government;
·
Code of Practice on
the Packaging, Labelling and Storage of Chemical Wastes (1992), EPD, Hong Kong
Government;
·
Works Branch Technical
Circular (WBTC) No. 32/92, The Use of Tropical Hard Wood on Construction Site,
Works Branch, Hong Kong Government;
·
WBTC No. 2/93,
Public Dumps, Works Branch, Hong Kong Government;
·
WBTC No. 2/93B,
Public Filling Facilities, Works Branch, Hong Kong Government;
·
WBTC No. 16/96, Wet
Soil in Public Dumps, Works Branch, Hong Kong Government;
·
WBTC Nos. 4/98 and
4/98A, Use of Public Fill in Reclamation and Earth Filling Projects, Works
Bureau, Hong Kong SAR Government;
·
WBTC Nos. 25/99,
25/99A and 25/99C, Incorporation of Information on Construction and Demolition
Material Management in Public Works Sub-committee Papers; Works Bureau, Hong
Kong SAR Government;
·
WBTC No. 12/2000,
Fill Management; Works Bureau, Hong Kong SAR Government;
·
WBTC No. 19/2001,
Metallic Site Hoardings and Signboards, Works Bureau, Hong Kong SAR Government;
·
WBTC No. 11/2002,
Control of Site Crusher, Works Bureau, Hong Kong SAR Government;
·
WBTC No. 12/2002,
Specification Facilitating the Use of Recycled Aggregates. Works Bureau, Hong
Kong SAR Government;
·
ETWB TC(W) No.
34/2002, Management of Dredged/Excavated Sediment;
·
ETWB TC(W) No.
19/2005 Environmental Management on Construction Site; Environment, Transport
and Works Bureau, Hong Kong SAR Government.
·
DEVB TC(W) No.
6/2010, Trip Ticket for Disposal of Construction and Demolition Materials;
·
DEVB TC(W) No.
8/2010, Enhanced Specification for Site Cleanliness and Tidiness;
·
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
·
Hong Kong Blueprint
for Sustainable Use of Resources 2013-2022, Environment Bureau, May 2013;
6.3.1
The potential environmental impacts associated with the
handling and disposal of waste arising from the construction and operation of
the Project were assessed in accordance with the criteria presented in Annexes
7 and 15 of EIAO-TM and summarised as follows:
·
Estimation of the types and quantities of the wastes to be
generated based on information provided by the Engineering Design Team and the
relevant research and studies on waste arisings;
·
Assessment of the secondary environmental impacts due to
the management of waste with respect to potential hazards, air and odour emissions, noise, wastewater discharges and traffic;
and
·
Assessment of the potential impacts on the capacity of
waste collection, transfer and disposal facilities.
Construction Phase
6.4.1
The proposed works include the following construction
activities:
·
Construction of tidal
barrier;
·
Construction of pumping
stations;
·
Refinements to the
existing intersection of YLN and Yuen Long Bypass Floodway (YLBF);
·
Excavation at the
downstream of YLN; and
·
Construction and
modification of flood walls
6.4.2
Construction activities will result in the generation of a
variety of C&D materials. The
C&D materials are usually mixed consisting of inert components (public
fill) such as soil, rock, concrete, brick, and asphalt etc. and non-inert
components (C&D waste) comprising metal, timber, paper, plastic and general
refuse. Sediment accumulated on the
concrete lined section of YLN will need to be removed to facilitate channel
widening and deepening works. Chemical waste may also arise as a result of
construction activities. Floating refuse
may arise from litter at upstream and floating refuse from Shan Pui River
through tidal water during heavy rain. The likely waste generated from the
proposed construction works can be classified into the following categories:
·
C&D materials;
·
Excavated sediments;
·
Chemical waste;
·
General refuse; and
·
Floating refuse
6.4.3
The construction and modification of flood walls involves minor
works at the existing parapet wall. The generation of C&D materials for
such works would be minimal.
Operation Phase
6.4.4
During operation period, only a small amount of silt
material and debris will be generated from the routine maintenance of the revitalised YLN. Similarly, small amount of screenings and
chemical waste will be generated from the routine operation and maintenance of
the pumping stations and tidal barrier.
6.4.5
Despite the small amount of wastes expected, handling and
disposal of the above-mentioned wastes may cause environmental impacts and
nuisance if it is not properly managed.
Construction Phase
C&D Materials
6.5.1
The majority of C&D materials generated from the
Project will arise during the construction of the pumping stations, tidal
barrier and revitalisation of YLN. It is
expected that most of this material will be broken pieces of concrete, soil and
rock from ground breaking and excavation works.
A preliminary estimate of the C&D materials and other wastes
generated, reused and disposed during construction is shown in Table
6.2.
6.5.2
Most of the C&D materials are inert and approximately
5.7% of the materials can potentially be reused on-site. For example, the generated soil can be
stockpiled for later reuse for backfilling.
6.5.3
However, there is limited potential to reuse the excavated
concrete. Nevertheless, the project team would explore
reusing the inert C&D materials in other concurrent projects at later
stage. For those inert C&D materials that cannot be reused, it is proposed
to dispose the materials at Tuen Mun Area 38 Fill
Bank via Yuen Long Highway, Tuen Mun Road, Wong Chu
Road, Lung Fu Road and Lung Mun Road or other approved public fill reception
facility. It is estimated that an
average of about 12 truck trips per day will be required to dispose these
materials off-site ([1]). In addition, it is
estimated that approximately 5,360 m3 of C&D wastes will be
generated and disposed of at WENT Landfill via Yuen Long Highway, Tuen Mun Road, Wong Chu Road, Lung Fu Road, Lung Mun Road
and Nim Wan Road. An average of about one truck trip
every other day will be required to dispose the C&D wastes to landfill.
6.5.4
With proper implementation of good site practices and
mitigation measures, no unacceptable environmental impacts are anticipated from
management of the C&D materials generated.
Table 6.2 Estimated Quantities of C&D Materials and
Other Wastes during Construction
Scope of Works
|
C&D Material Arisings (m3)
|
Reuse On-site (m3) (see Note 1)
|
Surplus C&D Materials (m3)
for Off-site Disposal
|
C&D Waste (m3)
(see Note 5)
|
Chemical Wastes
|
General Refuse
|
Floating Refuse
|
|
Tidal
Barrier
|
2,449
|
0
|
2,449
|
50
|
50 litres per month
(See Note 2)
|
32.5 kg per day (See Note 3)
|
(See Note 4)
|
|
Pumping
Stations
|
34,719
|
0
|
34,719
|
1,500
|
|
Deepened
Pump Sump
|
10,961
|
0
|
10,961
|
500
|
|
E&M
Control
|
4,564
|
0
|
4,564
|
200
|
|
Channel Widening (Inlet)
|
2,126
|
0
|
2,126
|
50
|
|
Channel Widening (Outlet)
|
3,624
|
0
|
3,624
|
60
|
|
Revitalisation of YLN
|
77,438
|
7,744
|
69,694
|
3,000
|
|
Total
|
135,881
|
7,744
|
128,137
|
5,360
|
|
Notes:
1
Suitable
rock should be reused as backfilling materials.
2
The amount
of chemical waste will be dependent on the contractor’s on-site maintenance
programme and the number of equipment and vehicles used on-site. Chemical
waste should be collected by licensed contractor and properly disposed of at
approved chemical waste treatment facilities.
Chemical waste will be generated throughout the construction period.
3
The
amount of general refuse will dependent on the contractor’s operating
procedures and housekeeping practices as well as the size of the workforce
on-site. All such wastes should be sorted, reused and recycled before
disposal at designated outlets. General refuse will be generated throughout
the construction period.
4
With proper waste management and education,
floating refuse arising from the construction activities is not anticipated.
For floating refuse not generated from the Project (i.e. litter at upstream
and floating refuse from Shan Pui River through tidal water), the quantity is
not estimated under this EIA. However, any floating refuse trapped within the
Project Area will be collected by contractor and disposed to landfill.
5
All
C&D waste should be sorted, reused and recycled as far as possible before
disposal at designated landfill.
|
Excavated Sediments
6.5.5
YLN was constructed in the 1960s into a concrete lined
channel. An inflatable dam was constructed to prevent tidal water of Deep Bay
from entering into Yuen Long Town. Over the years, a thin layer of sediment has
accumulated on the YLN bed section from the inflatable dam to the confluence of
old Kam Tin River. To facilitate the widening and deepening works of the
Barrage, the sediment above the concrete section of YLN will need to be
excavated for marine disposal according to prevailing guidelines. No marine
disposal is proposed for the excavated materials generated from other works
under the Project.
6.5.6
Based on site observation and preliminary estimation, the
sediment is expected to be generally about 0.5 m in depth. Since the length and
width of the YLN section requiring sediment excavation is about 500 m and 70 m,
the volume of sediment is conservatively estimated at approximately 17,500 m3.
Reusing the sediment as fill material within the Project will be further
considered in the detailed design stage subject to the sediment quality and
engineering design. The feasibility of reusing the sediment in other projects
would be limited. If on-site reuse of sediment is not feasible, then marine
disposal of sediment in accordance with ETWB TC(W) No. 34/2002 should be
followed.
6.5.7
Pursuant to Appendix G, 3(i) of
ESB-307/2018, a Sediment Sampling and Testing Plan (SSTP) with reference to
ETWB TC(W) No. 34/2002 was prepared and submitted to EPD for approval. This
Plan details the ranges of parameters to be analysed;
the number, type and methods of sampling; sample preservation; chemical and
biological laboratory test methods to be used. A total of twenty-two (22)
sampling locations were proposed. EPD expressed no further comment on 11 June
2020. MFC/CEDD expressed no comment in principle on the rationale for sediment
removal on 30 October 2020. Copy of the relevant correspondences and SSTP are
enclosed in Appendix
6.1a and Appendix 6.1b. The sampling location plan is shown in Figure 6.1.
6.5.8
Sediment sampling was undertaken on 7 September 2020 in the
excavation area in accordance with the agreed SSTP. Sampling and laboratory
testing were conducted by Wellab Limited (HOKLAS
Registration No. 083). As the depth of the sediment is only about 0.5 m,
surface grab sample was taken using Van Veen Grab Sampler lowered from a boat.
A total of eleven (11) surface grab samples were collected at locations S10,
S11, S14 to S22. Sediment samples were not collected at locations S01 to S09,
S12 and S13 after several attempts including relocations within the sampling
grid. It was considered that no sediment is deposited at these locations.
Results of chemical test are presented in Appendix
6.2. From the chemical testing results, Category H sediment was
identified. No further biological screening is required for the collected
sediment samples as the samples are classified as Category H with no contaminant
levels exceeding 10 times Lower Chemical Exceedance Level (LCEL). In accordance
with ETWB TC(W) No. 34/2002, Type 2 – Confined Marine Disposal should be
adopted for Category H sediment with no contaminant levels exceeding 10 times
LCEL.
6.5.9
The SSTP, testing results and disposal option presented
above are only to fulfill the EIA Study under the EIAO. A separate
SSTP/Sediment Quality Report in accordance with ETWB TC(W) No. 34/2002 would be
prepared when applying for the dumping permit under DASO. Additional SI
works, based on the SSTP, should then be carried out by the contractor in order
to confirm the disposal arrangements of the excavated
sediment. Sediment Quality Report (SQR), reporting the chemical and
biological screening results and the estimated quantities of sediment under
different disposal options, should then be submitted to EPD for agreement under
DASO.
Sediment Disposal Options and Quantities
6.5.10
Based on the screening results, the disposal options for
each of the sediment samples were determined in accordance with the ETWB TC(W)
No. 34/2002. Referring to the construction programme, the proposed works of the
Project comprises 3 primary construction phases. At phase 1, excavation works
will be carried out at the sections of YLN for channel deepening and widening
works, tidal barrier and pumping stations. At phase 2, excavation works will be
conducted underground for piling works and other related woks. As the sediment
in YLN is above +0.2 mPD, no sediment will be generated from this phase.
At phase 3, no excavation works will be carried out. Therefore, excavated
sediment will only be generated in phase 1. Estimated quantities of sediment
under the disposal option is presented in Table 6.3.
Table 6.3 Estimated
Quantities of Sediment under Disposal Option
|
Disposal
Option+
|
Corresponding Category
|
Estimated In-situ Quantity* (m3)
|
|
Phase 1
|
Phase 2
|
Phase 3
|
Total
(Phase 1, 2 & 3)
|
|
Confined
Marine Disposal at disposal site(s) allocated by MFC
|
Category
H Sediment
|
17,500
|
0
|
0
|
17,500
|
|
Total:
|
17,500
|
0
|
0
|
17,500
|
Notes:
* The quantities shown in the table are estimates only and will be subject to
further review during the detailed design and construction stage.
+ The
disposal option is proposed base on the sediment sampling and testing results
under this EIA study and is for this EIA study purpose only. The final disposal
option should be subject to the results of separate SSTP and SQR submitted
under the DASO and allocated by relevant authority.
6.5.11
The Project would seek to minimise the quantity of sediment
to be excavated and explore the opportunity to reuse the excavated sediment during
the detailed design stage. Sediment to be disposed at designated marine
disposal areas would be carried out in accordance with ETWB TC(W) No. 34/2002
and the disposal options for the excavated sediment shall follow the procedures
in ETWB TC(W) No. 34/2002. The recommended mitigation measures for marine
disposal are discussed in Section 6.6 below. No adverse
waste management implications are anticipated if the recommended mitigation
measures are implemented.
Chemical Waste
6.5.12
Wastes classified as chemical waste are listed in the Waste
Disposal (Chemical Waste) (General) Regulation.
Where the construction processes produce chemical waste, the contractor
must register with EPD as a chemical
waste producer. Chemical waste should be
collected by licensed contractor and properly disposed of at approved chemical
waste treatment facilities.
6.5.13
Variety of chemicals would be used for carrying out
construction activities. These chemicals
may include paints, petroleum products, spent lubricants, grease, mineral oil,
solvent and other chemicals used during construction activities. Accidental spillages of chemicals in the
works area may contaminate the top soils on exposed ground/earth. The contaminated soil particles may be washed
away by construction site runoff causes water pollution.
6.5.14
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 Regulation.
These hazards include:
·
Toxic effects to workers;
·
Adverse effects on water quality from spills; and
·
Fire hazards.
6.5.15
The amount of chemical waste cannot be accurately predicted
at this stage since it largely depends on the contractor’s housekeeping
measure. The amount is anticipated to be small (about 50 litres
per month) and it is recommended that good housekeeping measures should be
implemented to reduce the amount of chemical waste generated. The chemical
wastes will be collected by licensed collector for the disposal of at licensed
treatment facilities (e.g. Chemical Waste Treatment Centre (CWTC) at Tsing Yi)
in accordance with relevant regulation and guideline.
6.5.16
With the incorporation of suitable arrangements for the
storage, handling, transportation and disposal of chemical wastes under the
requirements stated in the Code of Practice on the Packaging, Labelling and
Storage of Chemical Waste, no unacceptable environmental impacts and hazards
will result from the handling, transportation and disposal of chemical waste
arising from the Project.
General Refuse
6.5.17
The presence of a construction site with workers and
associated site office will result in the generation of general refuse (mainly
consist of food waste, aluminium cans and waste
paper) which requires off-site disposal.
The storage of general refuse has the potential to give rise to adverse
environmental impacts. These include odour if the waste is not collected frequently, windblown
litter, water quality impacts if waste enters water bodies, and visual
impact.
6.5.18
Assuming up to 50 construction workers will be working on
site at any one time, with a general refuse generation rate of 0.65 kg per
worker per day ([2]), the amount of general
refuse to be generated will be about 32.5 kg per day. An adequate number of waste containers will
be provided to avoid spillage of waste.
6.5.19
Recyclable materials such as paper and aluminium
cans will be separated and delivered to the local recyclers. An adequate number of waste containers will
be provided to avoid spillage of waste.
The non-recyclable waste will be collected and disposed of at the
landfill on a regular basis. With
respect to the small quantity of general refuse to be transferred, it is not
anticipated that it will cause unacceptable operational impacts to these
facilities.
Floating Refuse
6.5.20
The litter from the upstream may come down along the nullah
to the Project Area. During heavy rain, the inflatable rubber dam may be
deflated and floating refuse in Shan Pui River may be subsequently washed up
onto the Project Area through tidal water. During construction phase, the
construction workforce may also generate floating refuse (e.g. waste paper and
empty containers) while working along the nullah. With proper waste management
and training to workers, floating refuse arising from the construction activities
is not anticipated. Any floating refuse trapped within the Project Area will be
collected by contractor and disposed of to landfill.
Operational Phase
6.5.21
During the operation phase, trash and sediment from the
upstream of YLN will be stored behind the tidal barrier. Therefore, maintenance
works will be carried out to remove trash and sediment regularly. Such waste
will be removed by manual means and disposed of to landfill after the clearance
works. No unacceptable environmental
impacts are thus anticipated.
6.5.22
Mechanical screens will be installed at the inlet chamber
of the pumping stations. Small amount of screenings will be generated. The
screenings will be properly packed and handled within the pumping station
structure to avoid odour and hygiene nuisance. The
screenings will then be transported to landfill for disposal. If the operation
of the pumping stations would produce chemical waste, the operator / authority
will register with EPD as a chemical waste producer. Routine maintenance of the
pumping stations will generate a very small amount of chemical waste. The
chemical wastes will be collected by licensed collector for the disposal of at
licensed treatment facilities (e.g. Chemical Waste Treatment Centre (CWTC) at
Tsing Yi) in accordance with relevant regulation and guideline. No unacceptable
environmental impacts are thus anticipated.
Construction Phase
C&D Materials
6.6.1
The HKSAR Government's construction and demolition waste
management policy follows the same hierarchy as for other wastes i.e. in order
of desirability: avoidance, minimisation, recycling,
treatment and safe disposal of waste. As the Project will generate more than 50,000 m3 of C&D materials,
a Construction and Demolition Material Management Plan (C&DMMP) should be
prepared and submit to the Public Fill Committee of CEDD in accordance with the
Project Administration Handbook for Civil Engineering Works."
6.6.2
Training of construction staff should be undertaken by the
contractor about the concept of site cleanliness and appropriate waste
management procedures. The contractor
should develop and provide toolbox talk for on-site sorting of C&D
materials to enhance workers’ awareness in handling, sorting, reuse and
recycling of C&D materials.
Requirements for staff training should be included in the contractor’s
Environmental Management Plan (EMP).
6.6.3
Good planning and site management practice should be
employed to eliminate over ordering or mixing of construction materials to
reduce wastage. Proper storage and site
practices will minimise the damage or contamination of construction materials.
6.6.4
Where waste generation is unavoidable, the potential for
recycling or reuse should be rigorously explored. If waste cannot be recycled, disposal routes
described in the EMP should be followed.
A recording system for the amount of wastes generated, recycled and
disposed (including the disposal sites) should be implemented. In order to monitor the disposal of C&D
material and solid wastes at public filling facilities and landfills and to
control fly-tipping, a trip-ticket system should be included. One may make reference to DEVB TC(W) No.
6/2010 for details.
6.6.5
Regular cleaning and maintenance of the waste storage area
should be provided.
6.6.6
Control measures for temporary stockpiles on-site should be
taken in order to minimize the noise, generation of dust, pollution of water
and visual impact. These measures include:
·
Surface of stockpiled soil should be regularly wetted with
water especially during dry season;
·
Disturbance of stockpiled soil should be minimized;
·
Stockpiled soil should be properly covered with tarpaulin
especially when heavy rain storms are predicted;
·
Stockpiling areas should be enclosed where space is
available;
·
Stockpiling areas should be located away from the water
bodies; and
·
An independent surface water drainage system equipped with
silt traps should be installed at the stockpiling area.
6.6.7
The identification of final disposal sites for C&D
materials generated by the construction works will be considered during the
detailed design stage of the Project when the volume and types of C&D
materials can be more accurately estimated.
The Public Fill Committee of CEDD should be consulted on designated
outlets (e.g. public filling area) for public fill, whilst EPD should be consulted on landfills for C&D
waste. Disposal of C&D waste to
landfill must not have more than 50% (by weight) inert material. The C&D waste delivered for landfill
disposal should contain no free water and the liquid content should not exceed
70% by weight.
6.6.8
In order to avoid dust or odour
impacts, any vehicle leaving a works area carrying C&D waste or public fill
should have their load covered up before leaving the construction site.
6.6.9
C&D materials should be disposed of at designated
public fill reception facilities or landfills.
Disposal of these materials for the use at other construction projects
is subject to the approval of the Engineer and/or other relevant reception
authorities. Furthermore, unauthorized
disposal of C&D materials in particular on private agricultural land is
prohibited and may be subject to relevant enforcement and regulating
actions. The disposal of public fill and
C&D waste will be controlled through trip-ticket system in accordance with
DEVB TC(W) No. 6/2010.
Concrete Waste
6.6.10
Dry concrete waste (considered as public fill) should be
sorted out from the other wastes and recycled for reuse or sorted out for disposal
at designated public filling facilities.
Wooden Materials
6.6.11
All wooden materials used on-site should be kept separately
from other wastes to avoid damage and to facilitate reuse. Timber which cannot be reused should be
sorted out from other wastes and stored separately from all inert wastes before
being disposed of to landfill.
6.6.12
Reusable steel or concrete panel shutters, fencing and
hoarding and signboard should be used as a preferred alternative to items made
of wood, to minimise wastage of wood.
Attention should be paid to WBTC No. 19/2001 - Metallic Site Hoardings
and Signboards to reduce the amount of timber used on construction sites. Metallic alternatives to timber are readily
available and should be used rather than new timber. Precast concrete units should be adopted
wherever feasible to minimize the use of timber formwork.
6.6.13
Only waste material is needed to be taken to a
landfill. It should be separated from
recyclable wood and steel materials. As
for all waste types, these materials should be reused on-site or other approved
sites before disposal is considered as an option. Disposal to landfill should only be
considered as a final option.
Contractors are responsible for storage of re-useable materials on-site.
On-site Sorting, Reuse and Recycling
6.6.14
All waste materials should be segregated into categories
covering:
·
Inert C&D materials suitable for reuse on-site;
·
Inert C&D materials suitable for public fill reception
facilities;
·
Recyclable C&D waste for recycling;
·
Remaining C&D waste for landfill;
·
Chemical waste; and
·
General refuse for landfill.
6.6.15
Proper segregation and disposal of construction waste should
be implemented. Separate containers should be provided for inert and non-inert
wastes.
6.6.16
Sorting is important to recover materials for reuse and
recycling. Specific area should be
allocated for on-site sorting of C&D materials and to provide a temporary
storage area for those sorted materials.
If area is limited, all C&D materials should at least be sorted
on-site into inert and non-inert components. Non-inert materials (C&D
waste) such as bamboo, timber, vegetation, packaging waste and other organic
materials should be reused and recycled wherever possible and disposed of to
the designated landfill only as a last resort.
Inert materials (public fill) such as concrete, stone, clay, brick,
soil, asphalt and the like should be separated and reused in this or other
projects (subject to approval by the relevant parties in accordance with the
DEVB TC(W) No. 6/2010) before disposed of at a public filling facility operated
by CEDD. Steel and other metals should
be recovered from demolition waste stream and recycled.
6.6.17
The reuse of inert materials such as soil, rock and broken
concrete should be maximised. Waste should be separated into fine, soft and
hard materials. With the use of a
crusher, coarse materials can be crushed to make it suitable for use as fill
materials where fill is required in the works.
This minimises the use of imported materials
and maximizes the use of the C&D materials produced.
Excavated Sediments
6.6.18
The sediment should be excavated, handled, transported and
disposed of in a manner that would minimize adverse environmental
impacts.
6.6.19
Requirements of the Air Pollution Control (Construction
Dust) Regulation, where relevant, shall be adhered to during excavation, transportation
and disposal of the sediment.
6.6.20
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.
6.6.21
For off-site disposal, the basic requirements and
procedures specified under ETWB TC(W) No. 34/2002 shall be followed. Marine
Fill Committee (MFC) of CEDD is managing the disposal facilities in Hong Kong
for the excavated sediment, while EPD is the authority of issuing marine
dumping permit under the Dumping at Sea Ordinance (DASO).
6.6.22
To ensure disposal space is allocated for the Project, the
Project Proponent should be responsible for obtaining agreement from MFC on the
rationale for sediment removal and the allocation of the disposal site. The
contractor(s), on the other hand, should be responsible for the application of
the marine dumping permit under DASO from EPD for the sediment disposal.
6.6.23
The excavated sediments are expected to be loaded onto the
barge at public barging point of which the exact location will be determined by
the contractor(s) and agreed by EPD/CEDD and transported to the designated
disposal sites allocated by MFC. The excavated sediment would be
disposed of according to its determined disposal options and ETWB TC(W) No.
34/2002.
6.6.24
Stockpiling of contaminated sediments should be avoided as
far as possible. If temporary stockpiling of contaminated sediments
is necessary, the excavated sediment should be covered by tarpaulin and the
area should be placed within earth bunds or sand bags to prevent leachate from
entering the ground, nearby drains and surrounding water bodies. The
stockpiling areas for contaminated sediments should be paved with impermeable
linings 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).
6.6.25
In order 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 shall be controlled to avoid splashing and
overflowing of the sediment slurry to the surrounding water.
6.6.26
The barge transporting the sediments to the designated
disposal sites shall be equipped with tight fitting seals to prevent leakage
and shall not be filled to a level that would cause overflow of materials or
laden water during loading or transportation. In addition,
monitoring of the barge loading shall be conducted to ensure that loss of
material does not take place during transportation. Transport barges or vessels
shall be equipped with automatic self-monitoring devices as specified by the
DEP.
Chemical Waste
6.6.27
Where the construction processes produce chemical waste,
the contractor must register with EPD as a chemical waste producer. Wastes classified as chemical wastes are
listed in the Waste Disposal (Chemical Waste) (General) Regulation. These
wastes are subject to stringent disposal routes. EPD requires information on the particulars
of the waste generation processes including the types of waste produced, their
location, quantities and generation rates.
A nominated contact person must be registered with EPD. An updated list of licensed chemical waste
collector can be obtained from EPD.
6.6.28
Storage, handling, transport and disposal of chemical waste
should be arranged in accordance with the Code of Practice on the Packaging,
Labelling and Storage of Chemical Wastes published by EPD, and should be
collected by a licensed chemical waste collector.
6.6.29
Chemical waste should be stored away from channels or water
bodies.
6.6.30
Suitable containers should be used for specific types of
chemical wastes. The containers should be properly labelled (in English and
Chinese in accordance with instructions prescribed in Schedule 2 of the
Regulations), resistance to corrosion, stored safely and closely secured. Stored volume should not be kept more than
450 liters unless the specification has been approved by the EPD. Storage
area should be enclosed by three sides by a wall, partition of fence that is at
least 2 m height or height of tallest container with adequate ventilation and
space.
6.6.31
Hard standing, impermeable surfaces draining via oil
interceptors should be provided in works area compounds. Interceptors should be regularly emptied to
prevent release of oils and grease into the surface water drainage system after
accidental spillages. The interceptor
should have a bypass to prevent flushing during periods of heavy rain. Oil and fuel bunkers should be bunded and/or
enclosed on three sides to prevent discharge due to accidental spillages or
breaches of tanks. Bunding should be of
sufficient capacity to accommodate 110% of the volume of the largest container
or 20% of the total volume of waste, whichever is largest. Waste collected from any grease traps should
be collected and disposed of by a licensed contractor.
6.6.32
Lubricants, waste oils and other chemical wastes are likely
to be generated during construction.
Used lubricants should be collected and stored in individual containers
which are fully labelled in English and Chinese and stored in a designated
secure place. If possible, such waste
should be sent to oil recycling companies, and the empty oil drums collected by
appropriate companies for reuse or refill.
6.6.33
The registered chemical waste producer (i.e. the
contractor) has to arrange for the chemical waste to be collected by licensed collectors. The licensed collector should regularly take
chemical waste to a licensed chemical waste treatment facility (such as the
Chemical Waste Treatment Centre in Tsing Yi).
A trip ticket system operates to control the movement of chemical
wastes.
6.6.34
No lubricants, oils, solvents or paint products should be
allowed to discharge into water courses, either by direct discharge, or as
contaminants carried in surface water runoff from the construction site.
General Refuse
6.6.35
General refuse generated on-site should be stored in
enclosed bins or skips and collected separately from other construction and
chemical wastes and disposed of at designated landfill. A temporary refuse collection point should be
set up by the contractor to facilitate the collection of refuse by reputable
contractors. The chemical wastes will be
collected by licensed collector for the disposal of at licensed treatment
facilities (e.g. Chemical Waste Treatment Centre (CWTC) at Tsing Yi) in
accordance with relevant regulation and guideline. 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.
6.6.36
The recyclable components of the general waste generated by
the workforce, such as aluminium cans, paper and
cleansed plastic containers should be separated from other waste. Provision and collection of recycling bins
for different types of recyclable waste should be set up by the
contractor. The contractor should also
be responsible for arranging recycling companies to collect these materials.
Floating Refuse
6.6.37
Any floating refuse trapped within the Project Area should
be collected by contractor and disposed of to landfill.
Operation Phase
6.6.38
The screenings, silt materials and debris collected during
operation and maintenance should be properly packed and transported to the
designated landfill for disposal as soon as possible. All chemical waste should
be properly stored, labelled and removed by licensed waste collectors in
accordance with Waste Disposal (Chemical Waste) (General) Regulation.
Introduction
6.7.1
This Section
identifies and assesses land lots and sites within the Project boundary which,
due to their past or present land uses, are potentially contaminated sites.
Relevant Legislation, Policies,
Standards and Criteria
6.7.2
The following requirements and guidelines are relevant to
assessment of land contamination.
·
Section 3.1 of
Annex 19 of EIAO-TM under the EIAO;
·
Guidance Note for
Contaminated Land Assessment and Remediation (August 2007);
·
Guidance Manual for
Use of Risk-Based Remediation Goals for Contaminated Land Management (December
2007); and
·
Practice Guide for
Investigation and Remediation of Contaminated Land (August 2011).
Assessment Methodology
6.7.3
According to the Practice Guide, site appraisal shall
precede to determine the need for site investigation, and to provide the
information to support a contamination assessment, which the findings will
subsequently determine if site remediation is required.
6.7.4
The site appraisal consists of the following:
·
desk-top review of existing and historical survey maps;
·
interpretation of existing and historical aerial
photographs;
·
review of land use record, permitted uses of existing
private lots;
·
site walkover to verify the collected information; and
·
review the relevant government records (i.e. Dangerous
Goods storage, spillage / leakage of chemicals, chemical wastes producers) of
the Project Site.
6.7.5
The site walkover was undertaken to identify any physical
clues of contamination, such as presence of industrial related building
structures, chemical drums, chemical or oil stains, unnatural colours / odours and abandoned
piping / mechanical components.
Site Appraisal Findings
Past Land Uses
6.7.6
A review of historical aerial photos
(from 1963 – 2018) was undertaken to identify the past land uses within the
project area in Yuen Long (Appendix 6.3). Based on the
historic photos, the land use in the area was cultivation land and squatters.
The proposed works along YLN only comprise works within the nullah itself,
where adjacent private lots would not be affected. And as for the works along
Kam Tin River, there would be no land excavation as only minor modifications to
the existing parapet walls are anticipated. Thus, land contamination is not
envisaged for either Yuen Long Nullah or Kam Tin River. According to the aerial
photos, there was no presence of building structures that would indicate
possible industrial activities in the proposed works area. A summary of the
review is provided in Table 6.4.
Table 6.4 Review
of Historical Aerial Photographs
|
Aerial Photo Reference
|
Year
|
Observed Land Use
|
|
Barrage
|
|
Fig No. 6.3_1
|
1963
|
The YLN had not been constructed yet. The surrounding
was mainly cultivation land.
|
|
Fig No. 6.3_2
|
1967
|
The width of the river had been enlarged
and the flow path of the river had been straightened. The YLN had been
constructed. Some squatters were observed along the riverbank.
|
|
Fig No. 6.3_3
|
1972
|
Part of the river bed are observed,
possibly related to low water level.
|
|
Fig No. 6.3_4
|
1981
|
The cultivation land located in the
north-west direction of the site was removed and filling work are observed.
The squatters were still occupying the riverbank.
|
|
Fig No. 6.3_5
|
1987
|
The land located in the north-west
direction of the site was covered with medium dense vegetation. An area of
vegetation clearance was observed in there, possibly related to site
formation work.
|
|
Fig No. 6.3_6
|
1990
|
A car park and the Leeman Hydraulic
Technology Company Limited were constructed in the north-west direction of
the site.
|
|
Fig No. 6.3_7
|
1993
|
The Fortune Pharmacal was constructed in
the east site direction of the site. The pond in the south-east of the site
was filled and the covered by medium dense vegetation.
|
|
Fig No. 6.3_8
|
1996
|
Construction works are observed along the
riverbank and a fibre dam was constructed upstream, not far away from the
proposed location of the Barrage. The Hong Kong School of Motoring was
constructed in the east direction of the site.
|
|
Fig No. 6.3_9
|
1999
|
The construction work observed in previous
year was still in process.
|
|
Fig No. 6.3_10
|
2018
|
The land along the sides of the riverbank
were covered by light dense vegetation.
|
|
Aerial Photo Reference
|
Year
|
Observed
Land Use
|
|
Modifications
to existing intersection of YLN and YLBF and Parapet Walls
|
|
Fig
No. 6.3_11
|
1963
|
The site for the proposed
modifications was cultivation land at that time. The YLN and YLBF had not been constructed
yet.
|
|
Fig
No. 6.3_12
|
1967
|
The cultivation land had
been converted into a nullah and has formed an integral part of YLN.
|
|
Fig
No. 6.3_13
|
1972
|
No significant changes are
observed.
|
|
Fig
No. 6.3_14
|
1981
|
No significant changes
are observed.
|
|
Fig
No. 6.3_15
|
1987
|
No significant changes
are observed.
|
|
Fig
No. 6.3_16
|
1990
|
No significant changes
are observed.
|
|
Fig
No. 6.3_17
|
1993
|
Construction of the Yuen
Long Highway had been started in north-east direction of the Site.
|
|
Fig
No. 6.3_18
|
1996
|
The construction of Yuen
Long Highway had been finished. No other significant changes are observed.
|
|
Fig
No. 6.3_19
|
1999
|
No significant changes
are observed.
|
|
Fig
No. 6.3_20
|
2018
|
No significant changes
are observed.
|
Present Land Uses
6.7.7
Site walkover was undertaken in March 2020 to verify existing
land uses and to identify potential sources and signs of contamination, such as
presence of industrial activities, chemicals, oil and hazardous waste handling
and storage locations, bulk storage tanks, sumps, pipelines, staining, decolouration, abnormal odours,
distressed vegetation, etc.
6.7.8
The walkover confirmed the area for constructing the
pumping stations and tidal barrier. The proposed pumping stations and tidal
barrier are currently vacant. No polluting activities / sources were observed
within the project site areas during the walkover. The proposed works will not
encroach upon any petrol filling stations, car repair / dismantling workshops,
industrial premises or other major polluting areas.
6.7.9
According to the Land Requirement Study Report, the
proposed construction works for the Project are all currently located within
Government Land. Representative photos showing the existing
site conditions are presented in Appendix 6.4.
Spillage / Leakage
Records
6.7.10
Fire Services Department (FSD) and EPD have been enquired
on any dangerous goods license and possible incident on spillage, leakage of
chemicals or dangerous goods and chemical waste producers at the Project Area.
Reply from FSD and EPD indicated that there have been no records of dangerous
goods license since Year 1990 and no records of any incidents of
spillage/leakage of chemical or dangerous goods with the Project Area in the
past 5 years. The relevant correspondences are
provided in Appendix 6.5.
6.7.11
The EPD’s Chemical Waste Producer Register was inspected in
September 2020 and no record of chemical producer was identified within the
Works Area.
Summary of Findings
6.7.12
The proposed works will be constructed on existing vacant
lands, carriageways, footpaths and the YLTN.
No signs of suspected land contamination due to past and present land
uses were identified from review of historical aerial photos and during site
walkover.
6.7.13
Based on the findings of the
land contamination appraisal, no signs of suspected land contamination due to
past and present land uses were identified from review of historical aerial
photos and during site walkover. As such, submission of a Contamination
Assessment Plan (CAP) as stated in Appendix G, 4.2 (i)
of ESB-307/2018 for further soil sampling and analysis is considered not
necessary.
6.8
Residual Environmental Impacts
6.8.1
With the implementation of the recommended mitigation
measures, no unacceptable residual impacts are anticipated from the
construction and operation of the Project.
Construction Phase
6.9.1
To facilitate monitoring and control over the contractors’ performance
on waste management, a waste monitoring and audit programme will be implemented
throughout the construction phase and a Waste Management Plan (WMP) will be
prepared and implemented by the contractor in accordance with ETWB TC(W) No.
19/2005. The aims of the monitoring and
audit programme are:
·
To review the WMP, which will form part of the EMP in
accordance with ETWB TC(W) No. 19/2005, including the quantities and types of
C&D materials generated, reused and disposed of off-site; the amount of fill
materials exported from/imported to the site and the quantity of timber used in
temporary works construction for each process/activity;
·
To monitor the implementation and achievement of the WMP on
site to assess its effectiveness; and
·
To monitor the follow-up actions on deficiencies
identified.
6.9.2
Site inspections will be undertaken each week. Particular attention will be given to the
contractor’s provision of sufficient spaces, adequacy of resources and
facilities for on-site sorting and temporary storage of C&D materials. The C&D materials to be disposed of from
the site will be visually inspected to ensure the absence of non-inert
materials (e.g. general refuse, timber, etc.).
The waste to be disposed of at landfills will as practicable contain no
observable inert or reusable/recyclable C&D materials (e.g. soil, broken
rock, metal, and paper/cardboard packaging, etc.). Any irregularities observed during the site
inspections will be raised promptly to the contractor for rectification.
6.9.3
The findings of the waste inspections will be reported in
the monthly Environmental Monitoring and Audit Report.
Operation Phase
6.9.4
No monitoring and audit are required during operation of
the Project.
6.10
Conclusion
6.10.1
Wastes generated by the construction activities are likely
to include C&D materials, excavated sediment and floating refuse from the
construction works, general refuse from the workforce and chemical waste from
any maintenance of construction plant and equipment. Provided that these identified wastes arisen
are handled, transported and disposed of using approved methods and that the
recommended good site practices are strictly followed in terms of the
avoidance-minimisation-reuse-recycling-disposal
hierarchy, unacceptable environmental impacts are not anticipated during
construction of the Project.
6.10.2
The recommended measures can be enforced by incorporating
them into the waste management requirements in the WMP as part of the EMP. Environmental site audit would be necessary
to ensure the implementation of proper waste management practices during
construction.
6.10.3
For the operation phase, trash and sediment are expected to
be produced by maintenance works of the tidal barrier. Such waste will be
removed by manual means and disposed of to landfill after the clearance
works. Small amount of screenings and
chemical waste will be generated and collected during operation and routine
maintenance of the pumping stations. No unacceptable environmental impacts are
anticipated with proper waste management practices.
6.10.4
A review of past and present land uses of the project site
was conducted. Based on desk-top review and site walkover, the presence of
contaminated land is not expected.