9.1
Introduction
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 are:
·
Management
of dredged materials;
·
Handling
and disposal of contaminated sediments;
·
Handling
and disposal of construction and demolition (C&D) materials arising from the
river modification, excavation and construction works; and
·
Management
of chemical waste and general refuse.
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.
9.2
Legislation
Requirements and Evaluation Criteria
The following discussion on legislative requirements
and evaluation criteria applies to both the construction and operational 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);
·
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).
9.2.1
Waste Disposal Ordinance (Cap 354)
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 not directly defined in
the WDO but is considered to fall
within the category of ‘trade waste’.
Trade waste is defined as waste from any trade, manufacturer or business
or any wasted building, or civil engineering materials, but does not include
animal waste.
Under the WDO,
wastes can only be disposed of at a licensed site. The WDO
provides for the issuing of licences for the collection and transport of
wastes. Licences are not, however,
currently issued for the collection and transport of construction waste or
trade waste.
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.
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$1 million or above is
required to open a billing account solely for the contract for waste
disposal. Application shall be made
within 21 days after the contract is awarded.
Depending on the percentage of inert materials in the
construction waste, inert construction waste can be disposed of at public fill
reception facilities. However mixed
construction waste can be disposed of at construction waste sorting facilities,
landfills and Outlying Islands Transfer Facilities which have different
disposal costs. The scheme encourages
reducing, reusing and sorting of construction waste such that the waste
producer can reduce their disposal fee. Table 9.1 summarises the government
construction waste disposal facilities, types of waste accepted and disposal
cost.
Table 9.1 Government Facilities for Disposal of C&D Materials
|
Government
Waste Disposal Facilities
|
Type of
Construction Waste Accepted
|
Charge
(HK$/Tonne)
|
|
Public fill reception facilities
|
Consisting entirely of inert construction waste
|
$27
|
|
Sorting facilities
|
Containing more than 50% by weight of inert construction
waste
|
$100
|
|
Landfills
|
Containing not more than 50% by weight of inert
construction waste
|
$125
|
|
Outlying Islands Transfer
Facilities
|
Containing any percentage of inert construction waste
|
$125
|
9.2.2
Waste Disposal (Chemical Waste) (General)
Regulation (Cap 354C)
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.
A person should not produce, or cause to be produced,
chemical wastes without registration with the 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.
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.
9.2.3
Land (Miscellaneous Provisions) Ordinance
(Cap 28)
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.
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 ETWB TCW No. 31/2004 “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.
9.2.4
Public Health and Municipal Services
Ordinance (Cap 132) - Public Cleansing and Prevention of Nuisances Regulation
This Regulation
provides a further control on the illegal dumping of wastes on unauthorised
(unlicensed) sites.
9.2.5
Dumping at Sea Ordinance (Cap 466)
This Ordinance came
into operation in April 1995 and empowers the Director of Environmental
Protection (DEP) to control the disposal and incineration of substances and
articles at sea for the protection of the marine environment. Under the Ordinance,
a permit from the DEP is required for the disposal of regulated substances
within and outside the waters of the Hong Kong SAR. The permit contains terms and conditions that
includes the following specifications:
·
Type
and quantity of substances permitted to be dumped;
·
Location
of the disposal grounds;
·
Requirement
of equipment for monitoring the disposal operations; and
·
Environmental
monitoring requirements.
Management of Dredged/Excavated Sediments for Marine Disposal
Marine disposal of any dredged/excavated sediment is
subject to control under the Dumping at
Sea Ordinance 1995. Dredged/excavated
sediment destined for marine disposal is classified based on its contaminant
levels with reference to the Chemical Exceedance Levels (CEL), as stipulated in ETWB TC(W) No.
34/2002: Management of
Dredged/Excavated Sediment. This
Technical Circular includes a set of sediment quality criteria, as presented in
Table 9.2, which includes heavy
metals and metalloids, organic pollutants and a class of contamination level
for highly contaminated sediment not suitable for marine disposal.
Table 9.2 Dredged/Excavated
Sediment Quality Criteria for the Classification under the ETWB TC(W) No. 34/2002
|
Contaminants
|
Lower Chemical Exceedance Level (LCEL)
|
Upper Chemical Exceedance Level (UCEL)
|
|
Metals (mg kg-1 dry weight)
|
|
Cd
|
1.5
|
4
|
|
Cr
|
80
|
160
|
|
Cu
|
65
|
110
|
|
Hg
|
0.5
|
1
|
|
Ni (a)
|
40
|
40
|
|
Pb
|
75
|
110
|
|
Silver (Ag)
|
1
|
2
|
|
Zinc (Zn)
|
200
|
270
|
|
Metalloid
(mg kg-1 dry weight)
|
|
Arsenic (As)
|
12
|
42
|
|
Organic-PAHs (mg
kg-1 dry weight)
|
|
Low Molecular Weight (LMW) PAHs
|
550
|
3,160
|
|
High Molecular Weight (HMW) PAHs
|
1,700
|
9,600
|
|
Organic-non-PAHs
(mg
kg-1 dry weight)
|
|
Total PCBs
|
23
|
180
|
|
Organometallics
(mgTBT l-1 in interstitial water)
|
|
Tributyl-tin (a)
|
0.15
|
0.15
|
|
Note:
(a)
The
contaminant level is considered to have exceeded the UCEL if it is greater
than the value shown.
|
In accordance with ETWB TC(W)
No. 34/2002, the sediment is classified into three categories based on its
contamination levels:
Category L : Sediment with all contaminant levels not
exceeding the LCEL. The material must be
dredged, transported and disposed of in a manner which reduces the loss of
contaminants either into solution or by re-suspension.
Category M : Any one or more contaminants in the sediment
exceeding the LCEL with none exceeding the UCEL. The material must be dredged and transported
with care, and must be effectively isolated from the environment upon final
disposal unless appropriate biological tests demonstrate that the material will
not adversely affect the marine environment.
Category H : Any one or more contaminants in the sediment
exceeding the UCEL. The material must be
dredged and transported with great care, and must be effectively isolated from
the environment upon final disposal.
Figure
9.1 summarises the
sediment classification and disposal arrangements. EPD will use the sediment and biological test
results to determine the most appropriate disposal site (e.g. open sea or
confined marine disposal site).
Figure 9.1 Management
Framework for Dredged/Excavated Sediment
|
|
Notes:
1.
Most
open sea disposal sites are multi-user facilities and as a consequence their
management involves a flexibility to accommodate varying and unpredictable
circumstances. Contract documents will include provisions to allow the same
degree of flexibility to divert from one disposal site to another during the
construction period of a contract.
2.
Dedicated
Sites will be monitored to confirm that there is no adverse impact.
3.
For
sediment requiring Type 2 or Type 3 disposal, contract documents will state the
allocation conditions of Marine Fill Committee (MFC) and DEP. At present, East Sha Chau Mud Pits are designated
for confined marine disposal.
4.
If
any sediment suitable for Type 3 disposal (Category H sediment failing the
biological dilution test) is identified, it is the responsibility of the
project proponent, in consultation with DEP, to identify and agree,
the most appropriate treatment and/or disposal arrangement. Such a proposal is
likely to be very site and project specific and therefore cannot be prescribed.
This does not preclude treatment of this sediment to render it suitable for
confined marine disposal.
5.
The
allocation of disposal space may carry a requirement for the project proponent to
arrange for chemical analysis of the sediment sampled from 5% of the vessels
en-route to the disposal site. For Category M and certain Category H sediment,
the chemical tests will be augmented by biological tests. Vessel sampling will
normally entail mixing five samples to form a composite sample from the vessel
and undertaking laboratory tests on this composite sample. All marine disposal
sites will be monitored under the general direction of the CEDD. However,
exceptionally large allocations might require some additional disposal site
monitoring. These will be stipulated at the time of allocation.
6.
Trailer
suction hopper dredgers disposing of sediment at the East Sha
Chau Mud Pits must use a down-a-pipe disposal method,
the design of which must be approved in advance by Director of the CEDD. The
dredging contractor must provide equipment for such disposal.
Source: Appendix C, ETWBTC(W) 34/2002
In addition, in accordance with Building Ordinance
Office Practice Note for Authorised Persons and Registered Structural Engineers
No. 252, any proposal to remove more than 500,000 m3 of clean mud or
any quantity of contaminated mud must be justified on both cost and
environmental grounds. The rationale for
such removal will also be provided to enable an allocation for disposal to be
considered. Therefore it is desirable to
demonstrate that any proposed mud dredging has been reduced as far as
reasonably and safely practicable and to obtain, in-principle, an agreement
from the Secretary of the Marine Fill Committee (MFC) of the CEDD at an early
stage.
9.2.6
Other Relevant Guidelines
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;
·
ETWBTC(G) No. 2/93B, Public Filling
Facilities, Works Branch,
Hong Kong Government;
·
Waste Reduction Framework Plan, 1998 to
2007, Planning,
Environment and Lands Bureau, Government Secretariat, 5 November 1998;
·
ETWB TC(W) 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;
·
ETWB TC(W) No. 12/2000, Fill Management; Works Bureau, Hong Kong SAR Government;
·
ETWB TC(W) Nos.
6/2002 and 6/2002A,
Enhanced Specification for Site Cleanliness and Tidiness. Works Bureau, Hong Kong SAR Government; and
·
ETWB TC(W) No.
34/2002, Management of Dredged/Excavated Sediment; Environment, Transport and Works Bureau, Hong Kong SAR Government.
·
ETWB
TC(W) No. 19/2005
Environmental Management on Construction Site; Environment,
Transport and Works Bureau, Hong Kong SAR
Government.
9.3
Expected Waste Sources
9.3.1
Construction Phase
During the construction phase, the main activities,
which will result in the generation of waste, include dredging of river sediment,
soil excavation, embankment construction, sewage diversion works, landscaping
works (collectively referred as “river modification and associated works”), and
boundary patrol road and boundary fence re-provisioning (referred as “advanced
works”). The typical waste types
associated with these activities include:
·
Dredged
river sediment;
·
C&D
materials;
·
Chemical
waste; and
·
General
refuse.
9.3.2
Operation Phase
Maintenance
dredging of sediment may be required at the flood retardation pond. As the flood retardation pond is about 2.2
ha, the scale and volume of the dredging required will be significantly smaller
than that during the capital work construction.
9.4
Assessment
Methodology
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 the 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.
9.5
Waste Management
Assessment
9.5.1
Construction Phase
Dredged River Sediment
Sediment Sampling and Testing under the Feasibility
Study
The construction of the Project will
require excavation and disposal of river sediments. Under the Planning
and Feasibility Study for Training of Upstream Section of Shenzhen River,
twenty (20) river sediment samples were collected at five (5) locations within
the Study Area and tested in accordance with the requirements stipulated in the
ETWB TC(W) No.
34/2002 for an initial assessment of the nature of contaminated materials
in the river sediment and the locations of the contaminated sediments. Sediment samples were collected along the vertical
profile of the proposed dredging layers (ie the top
of the sediment layer, 0.9 m, 1.9m, 2.9 m below the seabed, and at the maximum
excavation depth, upon refusal or when rock head is encountered) at each
location.
Sediment Sampling and Testing under this EIA
A sediment sampling programme has been
undertaken as part of this EIA Study to delineate the locations of the contaminated
sediment and enable subsequent estimation of different types of sediments (ie contaminated and uncontaminated sediments) to be
disposed of for the purpose of the EIA.
A Sediment Sampling and Testing Plan has been prepared and submitted to
the EPD (see Annex E1). River bed sediment samples have been
collected at eight (8) locations (Figure
9.2). The proposed dredging
activity for the Project is anticipated to be limited to approximately 1 m
along the river course and up to around 5 m in the future flood retardation
pond area. Grab sampling method has been
used to collect surface sediment for locations where dredging will be limited
to 1 m or less. Where excavation is
expected to go down to 5 m (ie sampling location
SR4), sediment samples were collected along the vertical profile of the
proposed dredging layers (ie the top of the sediment
layer, 0.9 m, 1.9m, 2.9 m below the seabed, and at the maximum excavation
depth, upon refusal or when rock head is encountered). The sediments samples were then tested in
accordance with the requirements stipulated in the ETWB TC(W) No. 34/2002.
Sediment Analytical Results
The sediment analytical results are
presented in Table 9.3. The full laboratory analytical results are
contained in Annex E2. Sediment from 21 of the 33 samples tested were found
with all contaminant levels not exceeding the LCEL and thus classified as
Category L materials. The heavy metals
concentrations in 6 samples were found between the LCEL and UCEL and thus
classified as Category M contaminated materials. The concentrations in 6 samples were found
exceeded the UCEL and thus classified as Category H contaminated
materials.
Tier III biological screening was conducted to
identify the most appropriate disposal option for the Category M contaminated
materials in accordance with the ETWB TC(W) No. 34/2002.
Results of the biological screening indicated that of the 6 sediment
samples tested, two samples (ie SD5 2.9m & SR8)
passed all three toxicity tests while sediment from the rest 4 samples failed
in at least one of the three toxicity tests.
The latest design information
of the Project shows that about 95,000 m3 (in situ volume) of sediments would be dredged during the
construction phase of the Project. Based on the
sediment testing results, it is estimated that about 27,000 m3 (in situ volume) would be Category L
sediment. About 4,000 m3 (in situ volume) would be Category M
contaminated sediments (passed biological screening), whereas about 64,000 m3
(in situ volume) would be Category M
contaminated (failed biological screening) sediments or Category H contaminated
sediment. The detailed breakdown of
estimated quantities of different types of river sediments to be dredged from
this Project is summarised in Table 9.4.
Table 9.4 Estimated
Quantities of Different Sediments to be Dredged
|
Works Area
|
Period
|
Category L Sediment (m3)
|
Category M - (passed biological
screening) (m3)
|
Category M (failed biological
screening) and Category H (m3)
|
Total (m3)
|
|
I
|
2013 Q4 – 2014 Q1
|
-
|
4,000
|
11,600
|
15,600
|
|
II
|
2013 Q4 – 2014 Q1
|
4,000
|
-
|
18,000
|
22,000
|
|
III
|
2014 Q4 – 2015 Q1
|
-
|
-
|
21,600
|
21,600
|
|
IV
|
2014 Q4 – 2015 Q1
|
23,000
|
-
|
12,800
|
35,800
|
|
Total
|
|
27,000
|
4,000
|
64,000
|
95,000
|
Due to the space limitation, onsite disposal of sediment along
the riverside within the Project Site is considered not practical. In addition, potential environmental impacts,
such as leachate, odour,
air and noise impacts etc, may occur if sediments are
not properly disposed. Therefore all
sediments will be disposed offsite.
A site search in Shenzhen and Hong
Kong has been carried out to identify the potential disposal sites
for sediments. The Huangmao
Dao in Zhuhai is one of the major marine disposal
sites in the South China Sea which only
accepts uncontaminated spoils. And
currently there is no facility available for disposal of contaminated sediment
in Shenzhen. In Hong
Kong, the Marine Fill Committee (MFC) of CEDD has maintained
various marine disposal areas within the HKSAR for disposing of sediment at different
level of contamination in accordance with the ETWB TC(W) No. 34/2002.
After reviewing the site disposal options, it is
proposed that Category L sediments are to be disposed of at Huangmao
Dao. Category M (passed biological
screening) sediments are to be disposed of at Type 1 Open Sea / Type 1 Open Sea
(Dedicated Sites) disposal areas in HKSAR.
These facilities are designated by the State or Hong Kong SAR Government
and therefore the associated environmental impacts are considered to be
negligible.
Type 2 confined marine disposal site in Hong Kong is the only designated disposal site available
for contaminated sediment for the Project.
As the Project Site located at the boundary of the HKSAR and the Shenzhen Municipality and the works area covered both
municipalities,
the origin of contaminated sediment cannot be clearly distinguished. Disposal of all Category M contaminated
(failed biological screening) sediments or Category H contaminated sediment at
the Type 2 confined marine disposal site in Hong Kong is therefore considered
as the only appropriate option.
The proposed disposal options for the respective
categories of river sediment arising from the Project are provided in Table 9.5.
Table 9.5 Proposed
Disposal Options for River Sediments
|
Types of Sediment
|
In-situ Volume (m3)
|
Proposed Disposal Location
|
|
Category L
|
27,000
|
Huangmao Dao in Zhuhai
|
|
Category M (passed
biological screening)
|
4,000
|
Type 1 Open Sea Disposal (Dedicated
Sites) to the areas managed by the CEDD in the HKSAR
|
|
Category M (failed
biological screening) and Category H
|
64,000
|
Type 2 Confined Marine
Disposal to the facilities managed by the CEDD in the HKSAR (a)
|
|
Total
|
95,000
|
-
|
|
Note:
(a) The existing facility in Hong Kong receiving Type 2 sediment is East Sha Chau Contaminated Mud
Pit. It is understood that the
anticipated closure year of this facility is around 2014 and a new
contaminated mud receiving facilities in South of Brothers is under planning
by CEDD.
|
The testing results and the disposal options presented
in this Report are for EIA purposes only.
To confirm the sediment disposal quantity and location, a separate
Sediment Sampling and Testing Plan (SSTP) and Sediment Quality Report (SQR)
will be prepared in accordance with the requirement stated in ETWB TC(W) No.
34/2002 for EPD approval as required under the Dumping at Sea Ordinance.
The final disposal site will be determined by the MFC of CEDD and a dumping licence will be
obtained from EPD prior to the commencement of the dredging works.
The
Shenzhen River Regulation Office and the DSD will obtain confirmation from the
MFC in Hong Kong and the Shenzhen Marine
Management Office (深圳海洋管理處) for the proposed disposal arrangement before the
commencement of the construction works.
Dredging work will only be proceeded after all issues on management of
dredged sediments have been resolved and all relevant arrangements have been endorsed
by the relevant authorities, including EPD, MFC and the Shenzhen Marine
Management Office.
Potential Environmental Impacts Associated with the
Disposal of Dredged Sediment
The dredged sediments and the excavated spoils will
be temporary stored at separate stockpiling areas within the Project Site. In order to avoid secondary pollution during
transportation, the dredged sediment will be dewatered at the stockpiling areas
before disposal. The filtrates resulted
from dewatering will be sent to the on-site sedimentation tanks before
discharge back into the river.
The dewatered sediment will then be loaded onto trucks
and transported to Shekou Pier via
Yan Fang Road
(on the Shenzhen side) for further transporting to designated disposal areas depending on their level of
contamination. It is estimated that a
maximum of 71 truck trips per day will be required to dispose sediment
offsite (). In fact, it is very likely that the number of
truck trips will be lower given that the volume the dredged sediment will be
reduced after dewatering.
The potential dust, gaseous emissions and odour
impact associated with the transportation of sediment / surplus C&D
materials have been discussed in the Section
4 Air Quality Impact Assessment. With the implementation of good site
practices and proper mitigation measures, no adverse air and odour impact is
anticipated.
The disposal of dewatered dredged sediment will be
conducted during day-time and given the number of truck trips generated per
day, noise nuisance is not anticipated.
The transportation routes will be located within the Shenzhen Bay and is far away from the Mai Po
Marsh. Potential impact on birds in Mai
Po Marsh is therefore not anticipated.
C&D Materials
Advanced Works
It is estimated that about 15,000m3
of C&D materials will be generated from site clearance, fence installation
and checkpoint removal and construction activities during the Project’s
advanced works. The inert C&D
materials are mainly broken concrete from demolition of existing structures and
fence footings, broken bituminous materials from demolition of existing
boundary patrol road and steel from demolition of existing boundary fence. These materials are not suitable for reuse on
site and will therefore be disposed off site.
The materials will be properly sorted on site before delivered to the
designated public fill reception facility.
A small quantity of 3,750 m3 of construction waste will be
disposal of at the NENT Landfill.
River Modification and the Associated Works
It is estimated that about 586,000 m3
of inert C&D materials (excavated materials such as soils and rocks) will
be generated from river widening, embankment construction, sewage diversion and
landscaping works. All inert C&D
materials will be properly sorted on site and stored separately. It is estimated that about 114,800 of inert
C&D materials will be reused on-site for backfilling or embankment
construction and the surplus C&D materials (about 471,200 m3)
will be sent to Huangmao Dao (黃茅島) in Zhuhai. The estimated quantities of C&D materials
to be generated and reused at different works areas are summarised in Table 9.6.
Table 9.6 Quantities
of Excavated Materials at Each Works Area
|
Works Area
|
C&D Material (Excavated Materials) Arisings
(m3)
|
Reuse On-site (m3)
|
Surplus C&D Materials (m3) for Off-site Disposal
|
|
I
|
124,360
|
20,840
|
103,520
|
|
II
|
136,400
|
8,800
|
127,600
|
|
III
|
245,580
|
32,000
|
213,580
|
|
IV
|
79,660
|
53,160
|
26,500
|
|
Total
|
586,000
|
114,800
|
471,200
|
About 9,200 m3 of construction
waste, such as superficial soil with vegetations, timber and general refuse
will be generated from site clearance.
These non-inert materials will be sent to landfills in Shenzhen for
disposal.
The Shenzhen
River Regulation Office and the DSD shall obtain confirmation from the Public
Fill Committee (PFC) in Hong Kong and the
Shenzhen Marine Management Office (深圳海洋管理處) for the proposed disposal arrangement before the
commencement of the construction works.
Construction work will only be proceeded after
all issues on management of C&D material have been resolved and all
relevant arrangements have been endorsed by the relevant authorities, including
EPD, PFC and the Shenzhen Marine Management Office.
Potential Environmental Impacts Associated with the
Disposal of C&D Materials
The surplus inert C&D materials (public fill) and
construction waste generated from the advanced works will be disposed of at
public fill reception facilities and landfill in Hong Kong,
respectively. It is estimated that a
total of 8 truck trips per days (about 6 truck trips per day for public fill
and 2 truck trips per days for construction waste) will be required to dispose
the materials/waste off-site respectively ()
. In view of the small quantity of C&D
materials generated and with proper implementation of good site practices and
mitigation measures recommended in Sections
4.6, potential water quality, dust and noise impacts associated with
on-site handling and transportation of the public fill and construction waste
to disposal sites are not expected.
The surplus inert C&D materials generated from
river modification works will be sent to Shekou Pier by land transport on the Shenzhen side for
further transporting to Huangmao Dao in Zhuhai. It is
estimated that about 148 truck trips per day will be required to dispose inert
C&D materials during peak construction period ()
. It is also estimated that a maximum of 5
truck trips per day will be required to dispose the non-inert materials to
landfills in Shenzhen. With proper implementation of
good site practices and mitigation measures, no adverse environmental impact is anticipated.
Chemical Wastes
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. A complete list of such substances is
provided under the Regulation; however, substances likely to be generated from
the construction of the advanced works and river modification works under this
Project will, for the most part, arise from the maintenance of construction
plant and equipment. These may include,
but not limited to the following:
·
Scrap
batteries or spent acid/alkali from their maintenance;
·
Used
engine oils, hydraulic fluids and waste fuel;
·
Spent
mineral oils/cleaning fluids from mechanical machinery; and
·
Spent
solvents/solutions from equipment cleaning activities.
Chemical wastes may pose environmental, health and
safety hazards if not stored and disposed of in an appropriate manner as
outlined in the Waste Disposal (Chemical
Waste) (General) Regulation and the Code
of Practice on the Packaging, Labelling and Storage of Chemical Wastes. These hazards may include:
·
Toxic
effects to workers;
·
Adverse
effects on air, water and land from spills; and
·
Fire
hazards.
The amount of chemical waste that will arise from the
construction activities will be highly dependent on the Contractor’s on-site maintenance
activities and the quantity of plant and equipment utilized. With respect to the nature of construction
works and the number of equipment to be used on site, it is estimated that
about a few hundred litres of used lubricant oil will be generated per month
during the construction period. It is
anticipated that the quantities of waste solvent will be minimal.
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
adverse environmental and health impacts, and hazards will result from the
handling, transportation and disposal of chemical waste arising from the
Project.
General Refuse
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.
Assuming up to 1,350 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 ()
, the amount of general
refuse to be generated will be about 878 kg per day. Assuming that the split of workers would be
1,050 workers for the River Modification and Associated Works and 300 workers
for the Advanced Works, the amount of general refuse generated per day would be
682.5 kg and 195 kg for the respective contract.
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 landfills
in Shenzhen (during the river modification and associated works) or the NENT
Landfill in HKSAR (during the advanced works) on a regular basis. With respect to the small quantity of general
refuse to be transferred, it is not anticipated that it will cause adverse
operational impact to these facilities.
9.5.2
Operation Phase
Dredged River Sediment from Maintenance Dredging
The frequency and scale of the maintenance dredging
required along the river channel and the flood retardation pond is anticipated
to be very small compared with the dredging works during the capital works
construction. The volume of sediment cannot be determined at this stage but is
anticipated to be significantly lower than the volume of capital work dredging
during the construction phase. The
disposal and handling of the dredged materials will follow the requirements
stipulated in the ETWB TC(W)
No. 34/2002.
9.6
Mitigation Measures
Waste Management Hierarchy
The various waste management options are categorised
in terms of preference from an environmental viewpoint. The options considered to be most preferable
have the least environmental impacts and are more sustainable in the long
term. The hierarchy is as follows:
·
Avoidance
and reduction;
·
Reuse
of materials;
·
Recovery
and recycling; and,
·
Treatment
and disposal.
The above hierarchy has been used to evaluate and
select waste management options. The aim
has been to reduce waste generation and reduce waste handling and disposal
costs.
Should waste be disposed of in the HKSAR, all
contractors will consult the EPD for the final disposal of wastes and as
appropriate implement the standard site practices and mitigation measures
recommended in this EIA and those given below.
·
Nomination
of approved personnel to be responsible for standard site practices,
arrangements for collection and effective disposal to an appropriate facility
of all wastes generated at the Project Site;
·
Training
of site personnel in proper waste management and chemical handling procedures;
·
Provision
of sufficient waste disposal points and regular collection for disposal;
·
Appropriate
measures to reduce windblown litter and dust transportation of waste by either
covering trucks or by transporting wastes in enclosed containers;
·
Separation
of chemical wastes for special handling and appropriate treatment at the
licensed hazardous waste treatment facility in Shenzhen (during the river
modification and associated works) or the Chemical Waste Treatment Centre at Tsing Yi (during the advanced works);
·
Regular
cleaning and maintenance programme for drainage systems, sumps and oil
interceptors; and
·
A
recording system for the amount of wastes generated/ recycled and disposal
sites.
Waste Reduction Measures
Good management and control can prevent generation of
significant amount of waste. Waste reduction
is best achieved at the planning and design stage, as well as by ensuring the
implementation of standard site practices.
Recommendations to achieve waste reduction include:
·
Segregation
and storage of different types of waste in different containers, skips or
stockpiles to enhance reuse or recycling of material and their proper disposal;
·
Encourage
collection of aluminium cans and waste paper by individual collectors during
construction with separate labelled bins provided to segregate these wastes
from other general refuse by the workforce;
·
Any
unused chemicals and those with remaining functional capacity will be recycled
as far as possible;
·
Use
of reusable non-timber formwork to reduce the amount of construction waste;
·
Prior
to disposal of construction waste, wood, steel and other metals will be
separated to the extent practical, for re-use and/or recycling to reduce the
quantity of waste to be disposed of to landfill;
·
Proper
storage and site practices to reduce the potential for damage or contamination
of construction materials; and
·
Plan
and stock construction materials carefully to reduce amount of waste generated
and avoid unnecessary generation of waste.
9.6.1
Dredged Sediments
To minimise any potential odour impact, the dredged sediment
will be stored in enclosed container and will be delivered to Shekou Pier by enclosed trucks.
The disposal of dredged river sediment will follow
the requirements stipulated in the ETWB TC(W)
No. 34/2002. Detailed sampling and chemical testing will
be carried out prior to the commencement of the dredging activities to confirm
the sediment disposal method. The final
disposal site will be determined by the MFC and a dumping licence will be
obtained from EPD prior to the commencement of the dredging works.
9.6.2
Excavated Materials
Management of Waste Disposal
During the advanced works, the contractor will open a
billing account with EPD in accordance with the Waste Disposal (Charges for Disposal of Construction Waste) Regulation
for the payment of disposal charges.
Every waste load transferred to Government waste disposal facilities in
HKSAR such as public fill, sorting facilities, landfills or transfer station
will require a valid “Chit” which contains the information of the account
holder to facilitate waste transaction recording and billing to the waste
producer. A trip-ticket system will be
established in accordance with ETWB TC(W) No. 31/2004 to monitor the reuse of surplus
excavated materials off-site and disposal of construction waste and general
refuse at landfills, and to control fly-tipping. The billing “chit” and trip ticket system
will be included as one of the contractual requirements and implemented by the
contractor.
Minimization of C&D Material Generation
Ways to minimise generation of C&D materials
include:
(i)
The
Contractor is required to submit the Waste Management Plan (WMP) for approval
by the Engineer with appropriate mitigation measures to deal with and allow
space for waste segregation. Different C&D materials should be sorted
into different categories for re-use/recycle. Day-to-day site operations
of the Contractor should be closely monitored to ensure compliance with the
approved WMP.
(ii)
The
designer shall ensure that the design of levels and dimensions are reasonably
accurate to avoid unnecessary demolition, excavation and fill.
(iii)
The
Contractor shall be encouraged to use long lasting materials such as steel and
poly-fibre for formwork on site.
(iv)
The
RSS shall control the disposal of public fill and C&D waste to the
designated public filling facilities and landfills respectively through the
implementation of a trip-ticket system according to ETWB TC(W)
No. 31/2004.
Maximization of C&D material Reuse, Recovery and Recycling
Ways to maximize the use of inert C&D material
include:
(i)
The Contractor shall review the WMP quarterly to improve the site
practice and maximise the use of inert C&D
material.
(ii)
Different sections of works shall be programmed to ensure the C&D
materials generated could be re-used by the other sections of works or works
contracts.
(iii)
Temporary storage areas should be identified to resolve programming
mismatch between excavation and filling works.
(iv)
The excavated soft inert C&D materials should be reused for backfilling
the boundary patrol road, channel embankment, etc. whenever practicable.
(v)
Good quality top soil should be reused for landscaping.
Ways to maximise the
re-use/recycle of C&D material and/or rock on site include:
(i)
Recyclable materials such as wood and metal should be salvaged for reuse
and inert materials utilized as public fill.
(ii)
Segregation and storage of different types of waste in different
containers, skips or stockpiles to enhance reuse or recycling of material and
their proper disposal. Prior to disposal of C&D waste, it is
recommended that wood, steel and other metals be separated for re-use and/or
recycling and inert waste utilized as fill material to minimize the quantity of
waste to be disposed of at landfills.
Ways to maximise the use of
recycled C&D materials include:
(i)
Relevant clauses would be incorporated in the Particular Specifications
to facilitate the use of recycled aggregates as far as practicable, such as,
temporary works, general fills and road sub-base.
To reduce the potential dust impacts of the
excavation works, the C&D materials will be wetted as quickly as possible
to the extent practice after filling.
9.6.3
Chemical Waste
During the advanced works, the contractor will be
registered with the EPD.
Chemical waste, as defined by Schedule 1 of the Waste
Disposal (Chemical Waste) (General) Regulation, will be handled in
accordance with the Code of Practice on
the Packaging, Handling and Storage of Chemical Wastes as follows. Containers used for storage of chemical
wastes will:
·
Be suitable for the substance they are
holding, resistant to corrosion, maintained in a good condition, and securely
closed;
·
Have a capacity of less than 450 litres
unless the specifications have been approved by the EPD; and
·
Display a label in English and Chinese in
accordance with instructions prescribed in Schedule
2 of the Regulations.
The storage area for chemical wastes will:
·
Be clearly labelled and used solely for the
storage of chemical waste;
·
Be enclosed on at least 3 sides;
·
Have an impermeable floor and bunding, of capacity to accommodate 110% of the volume of
the largest container or 20% by volume of the chemical waste stored in that
area, whichever is the greatest;
·
Have adequate ventilation;
·
Be covered to prevent rainfall entering
(water collected within the bund must be tested and disposed of as chemical
waste, if necessary); and
·
Be arranged so that incompatible materials
are appropriately separated.
Chemical waste will be disposed of:
·
Via a licensed waste collector; and
·
To a facility licensed to receive chemical
waste, such as the Chemical Waste Treatment Facility which also offers a
chemical waste collection service and can supply the necessary storage
containers.
9.6.4
General Refuse
General refuse will be stored in enclosed bins or
compaction units separately from construction and chemical wastes. A reputable waste collector will be employed
by the Contractor to remove general refuse from the site, separately from
construction and chemical wastes, on a daily basis to reduce odour, pest and
litter impacts. The burning of refuse on
site should be prohibited.
Recycling bins will be provided at strategic
locations to facilitate recovery of aluminium can and waste paper from the
site. Materials recovered will be sold
for recycling.
9.6.5
Staff Training
Training will be provided to workers on the concepts
of site cleanliness and appropriate waste management procedures, including
waste reduction, reuse and recycling at the beginning of the construction
works.
9.7
Residual
Environmental Impacts
With the implementation of the recommended mitigation
measures, no adverse residual impacts are anticipated from the construction and
operation of the Project.
9.8
Environmental Monitoring and
Audit Requirements
9.8.1
Construction Phase
To facilitate monitoring and control over the
contractors’ performance on waste management (for both advanced works, and
river modification works and the associated works), a waste monitoring and
audit programme will be implemented throughout the construction phase and a
Waste Management Plan (WMP) will be prepared and implemented 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 Environmental Management Plan (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.
Site inspections will be undertaken each month. 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
(eg general refuse, timber, etc). Furthermore, the waste to be disposed of at
landfills will as practicable contains no observable inert or
reusable/recyclable C&D materials (eg 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.
The findings of the waste inspections will be
reported in the Environmental Monitoring and Audit Reports.
9.8.2
Operation Phase
Waste management will be the maintenance party’s
responsibility to ensure that all wastes produced during the maintenance
dredging are handled and disposed of in accordance with the recommended
mitigation measures and EPD’s regulations and
requirements.
9.9
Conclusions
During the construction phase, the main activities, which
will result in the generation of waste, include dredging of river sediment,
soil excavation, embankment construction, sewage diversion works, landscaping
works, and patrol road and boundary fence re-provisioning. The waste types associated with these
activities include dredged river sediment, C&D materials, chemical waste,
sewage and general refuse.
It is estimated that the gross total
C&D materials generated from the Advanced Works will be about 18,750 m3. About 15,000 m3 will be inert but
are not suitable for reuse on site.
These materials will be disposed of in a public fill reception facility
in HKSAR. A small quantity of about
3,750 m3 of construction waste (non-inert C&D material) will be
disposal of at the NENT Landfill.
It is estimated that a gross total
excavated materials generated from the river modification and associated works
will be about 690,200m3, comprising 95,000 m3 of river
sediment, 586,000 m3 of inert C&D material and 9,200 m3
of non-inert C&D material (construction waste). For the 95,000 m3 river sediment,
about 27,000 m3 with all contaminants levels not exceeding the LCEL
(Category L) will be disposed of at Huangmao Dao in Zhuhai, and the remaining sediments (with Categories M and
H) of 68,000 m3 will be disposed of at the Type 1 (dedicated) and
Type 2 marine disposal facilities as appropriate within the HKSAR, to be
determined by the MFC of the CEDD. Of
the 595,200 m3 C&D materials, about 586,000 m3 are
inert in nature. About 114,800 m3 of
these inert C&D materials will be reused on site for backfilling or
embankment construction and the surplus inert C&D materials of about
471,200 m3 will be disposed of at Huangmao
Dao (黃茅島) in Zhuhai.
About 9,200 m3 of construction waste (non-inert
materials) will be generated and require disposed of at landfills in Shenzhen.
During the peak construction period, approximately
878.5 kg of general refuse will be generated (195 kg from Advanced Works and
682.5 kg from River Modification and Associated Works). General refuse will be disposed of at
landfills in Shenzhen or at NENT Landfill in the HKSAR (during the advanced
works). Provided that the general refuse
are properly collected and disposed of at regular intervals, no adverse
environmental impacts are envisaged.
Chemical waste will be handled in accordance with the
Code of Practice on the Packaging,
Handling and Storage of Chemical Wastes.
During the advanced work, the chemical waste will be collected by a
licensed chemical waste collector to the Chemical Waste Treatment Facility for
disposal. During the river modification
and the associated works, the chemical waste will be collected and disposed of
at licensed hazardous waste treatment facilities in Shenzhen.
Table 9.7 summarises the type, quantity and
disposal location of waste to be generated from the construction of this
Project.
Table 9.7 Summary
of Waste to be generated during Construction
|
Type of Waste
|
Quantity
|
Proposed Disposal
Location
|
|
Advance Work
|
|
|
|
Sediment
|
-
|
-
|
|
Surplus inert C&D materials (m3)
|
15,000
|
Public fill reception facility in HKSAR
|
|
Construction Waste (m3)
|
3,750
|
NENT Landfill
|
|
Chemical Waste
|
Few hundred litres per month
|
Chemical Waste Treatment
Centre in Tsing Yi.
|
|
General Refuse
|
195 kg per day
|
NENT Landfill in HKSAR
|
|
|
|
|
|
River Modification and
Associated Works
|
|
Sediment (m3)
|
|
|
|
Category L
|
27,000
|
Huangmao Dao in Zhuhai
|
|
Category M (passed biological screening)
|
4,000
|
Type 1 Open Sea Disposal (Dedicated Sites) to the
areas managed by the CEDD in the HKSAR
|
|
Category M (failed biological screening)
and Category H
|
64,000
|
Type 2 Confined Marine Disposal to the facilities
managed by the CEDD in the HKSAR
|
|
Surplus inert C&D materials (m3)
|
471,200
|
Huangmao Dao in Zhuhai
|
|
Construction Waste (m3)
|
9,200
|
Landfills in Shenzhen
|
|
Chemical Waste
|
Few hundred litres per month
|
To a facility licensed to
receive chemical waste in Shenzhen
|
|
General Refuse (kg per day)
|
682.5 kg per day
|
Landfills in Shenzhen
|
|
Notes:
1.
In-situ
volume
|
|
|
|
|
|
Maintenance dredging will be carried out along the
river channel and the flood retardation pond.
The volume of sediment cannot be determined at this stage but is
anticipated to be less than the volume of capital work dredging during the
construction phase. The disposal and
handling of the dredged materials will follow the requirement in the ETWB TC(W) No. 34/2002.
With the implementation of general good construction
site practices, it is not anticipated that the construction and operation of
the Project will cause adverse environmental impacts due to handling,
transportation and disposal of the wastes.