6.1.1
Waste
management issues associated with the dredging works for the proposed cruise
terminal would be related to dredged marine sediment generated from dredging of
the seabed to provide the manoeuvring basin of adequate draught for the cruise
vessels and construction and demolition (C&D) material generated from
dredging of the existing seawall at the southern tip of the former Kai Tak
Airport runway for construction of the quay deck structure. Potential environmental impacts that may
result from these identified wastes arisings are evaluated, and mitigation
measures on the handling, transportation and disposal of these wastes are
recommended with reference to the applicable waste legislation and guidelines.
6.2
Environmental Legislation, Policies, Plans, Standards and Criteria
6.2.1
The
criteria and guidelines for assessing waste management implications are set out
in Annex 7 and Annex 15 of the Technical Memorandum on Environmental Impact
Assessment Ordinance (EIAO-TM), respectively.
6.2.2
The following legislation relates to the handling, treatment and
disposal of wastes in the Hong Kong SAR and has been used in assessing
potential impacts:
l
Waste Disposal Ordinance (Cap. 354C)
l
Waste Disposal (Chemical Waste) (General)
Regulation (Cap. 354C)
l
Land (Miscellaneous Provisions) Ordinance (Cap.
28)
l
Public Health and Municipal Services Ordinance
(Cap. 132) - Public Cleansing and Prevention of Nuisances Regulation
l
Waste Disposal (Charges for Disposal of
Construction Waste) Regulation (Cap. 354N)
Waste
Management
6.2.3
The Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal
of wastes. 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. Under the WDO, wastes can be disposed of
only at designated waste disposal facilities.
6.2.4
Under
the WDO, the Chemical Waste (General) Regulation 1992 provides regulations for
chemical waste control, and administers the possession, storage, collection,
transport and disposal of chemical wastes.
The Environmental Protection Department (EPD) has also issued a
guideline document, the Code of Practice on the Packaging, Labelling and
Storage of Chemical Wastes (1992), which details how the Contractor should
comply with the regulations on chemical wastes.
6.2.5
The
Public Cleansing and Prevention of Nuisances Regulation provides control on
illegal tipping of wastes on unauthorised (unlicensed) sites.
Dredged
Marine Sediment
6.2.6
The
ETWB TCW No. 34/2002 sets out the procedure for seeking approval to dredge /
excavate sediment and the management framework for marine disposal of dredged /
excavated sediment. This Technical
Circular outlines the requirements to be followed in assessing and classifying
the sediment and explains the marine disposal arrangement for the classified
material. The sediment quality
criteria for the classification of sediment are presented in Table 6.1.
6.2.7
Dumping
permits from EPD are required for marine disposal of dredged materials.
Chemical
Waste
6.2.8
Under
the Waste Disposal (Chemical Waste) (General) Regulations, all producers of
chemical waste must register with EPD and treat their wastes, either utilising
on-site plant licensed by EPD, or arranging for a licensed collector to
transport the wastes to a licensed facility. The regulation also prescribes the
storage facilities to be provided on site, including labelling and warning
signs, and requires the preparation of written procedures and training to deal
with emergencies such as spillages, leakages or accidents arising from the
storage of chemical wastes.
Construction
and Demolition (C&D) Materials
6.2.9
The current policy related to the disposal of C&D material is
documented in the Works Branch Technical Circular No. 2/93, ‘Public
Dumps’. Construction and demolition
materials that are wholly inert, namely public fill, should not be disposed of
to landfill, but taken to public filling areas, which usually form part of
reclamation schemes. The Land
(Miscellaneous Provisions) Ordinance requires that dumping licences be obtained
by individuals or companies who deliver public fill to public filling
areas. The Civil Engineering and
Development Department (CEDD) issues the licences under delegated powers from
the Director of Lands.
6.2.10
Under the Waste Disposal (Charges for Disposal of Construction Waste)
Regulation, enacted in January 2006, construction waste delivered to a landfill
for disposal must not contain more than 50% by weight of inert material. Construction waste delivered to a
sorting facility for disposal must contain more than 50% by weight of inert
material, and construction waste delivered to a public fill reception facility
for disposal must consist entirely of inert material. The Environment,
Transport and Works Bureau (ETWB) TCW No. 31/2004, “Trip Ticket System for
Disposal of Construction & Demolition Materials” provides measures to track
the disposal of C&D materials.
Details of the ETWB TCW No. 31/2004 are given in Appendix 6.1a.
6.2.11
Measures
have been introduced under ETWB TCW No. 33/2002, “Management of Construction
and Demolition Material Including Rock” to enhance the management of
construction and demolition material, and to minimize its generation at source. The enhancement measures include: (i)
drawing up a Construction and Demolition Material Management Plan (C&DMMP)
at the feasibility study or preliminary design stage to minimize C&D
material generation and encourage proper management of such material; (ii)
vetting of the C&DMMP prior to upgrading of the project to Category A in
the Public Works Programme; and (iii) providing the contractor with information
from the C&DMMP in order to facilitate him in the preparation of the Waste
Management Plan (WMP) and to minimize C&D material generation during
construction. Projects generating
C&D material less than 50,000m3 or importing fill material less
than 50,000m3 are exempt from the C&DMMP. The new
ETWB TCW No. 19/2005 “Environmental Management on Construction Sites” includes
procedures on waste management requiring contractors to reduce the C&D
material to be disposed of during the course of construction. Under ETWB TCW No. 19/2005, the
contractor is required to prepare and implement an Environmental Management
Plan (EMP) and the WMP becomes part of the EMP. Reference should also be made
to the ETWB TCW No. 31/2004 “Trip Ticket System for Disposal of Construction
and Demolition Materials” as attached in Appendix 6.1a.
General
6.3.1
The
criteria for assessing waste management implications are outlined in Annex 7 of
the EIAO-TM. The methods for
assessing potential waste management impacts during the construction phase of
the Project follow those presented in Annex 15 of the EIAO-TM and include the
following:
l
Estimation of the types and quantities of the
wastes generated.
l
Assessment of potential impacts from the
management of solid waste with respect to potential hazards, air and odour
emissions, noise, wastewater discharge and transport.
l
Assessment of impacts on the capacity of waste
collection, transfer and disposal facilities.
Dredged
Marine Sediment
6.3.2
A
Sediment Sampling Proposal (SSP) was originally prepared by “Meinhardt
Infrastructure and Environmental Limited” in accordance with the technical
circular Management of Dredge / Excavated Sediment (ETWB TCW No. 34/2002) and
it is intended that the sampling and the testing results will be needed for
supporting future dumping permit application for the dredged spoil for the
proposed Cruise Terminal at Kai Tak.
The SSP was submitted and agreed with the Marine Dumpling Section of the
EPD on 14 September 2006 on the scope of works and testing requirements with
respect to ETWB TCW No. 34/2002.
6.3.3
In
order to fulfil the requirements of EIA Study Brief for the feasibility study
of Kai Tak Development, the scope of the sampling and testing services was
expanded and the Revised Sediment Sampling Proposal (RSSP) was submitted. The Revised Sediment Sampling Proposal
(RSSP Rev 2) was endorsed by EPD as partially fulfilled the requirements
stipulated in Sections 3.4.7.6(k) and 3.4.9.2(iii) of the EIA Study Brief for
the feasibility study of Kai Tak Development on 28 December 2006. The endorsed RSSP Rev 2 is included in Appendix 6.1 of this report.
6.3.4
Marine
site investigation (SI) to determine the contamination level of the seabed to
be dredged for the manoeuvring basin of the cruise terminal has been conducted
by CEDD under Agreement No. KDO 01/2006 in two phases for Sub-area A and
Sub-area B respectively (i.e. Phase A and Phase B respectively as stated in the
Sediment Quality Report (SQR) attached in Appendix 6.2). The first phase of the marine SI (for
Sub-area A) commenced on 15 January 2007 and was completed on 23 January 2007
and comprised 30 sampling stations (stations A01-A30) (refer to Figure 6.1). The second phase of the marine SI (for
Sub-area B) commenced on 23 February 2007 and was completed on 10 March 2007
and comprised 43 sampling stations (stations B01-B43) (refer to Figure 6.1). The marine SI comprised grab sampling
and vibrocoring to obtain sediment samples for chemical testing.
6.3.5
In
January 2007, Maunsell Consultants Asia Limited (MCAL) was commissioned by CEDD
to undertake Agreement No. CE35/2006 (CE) – Kai Tak Development Engineering
Study cum Design and Construction of Advance Works – Investigation, Design and
Construction. The dredging extent for the proposed Cruise Terminal has been
revised and is shown in Figure 2.4a. The RSSP Rev 2 has been reviewed in
relation to the revised dredging extent and it is consider that the sediment
sampling locations of RSSP Rev 2 are applicable and adequate for the revised
dredging extent. The RSSP Rev 2 was
accepted by EPD as partially fulfilled the requirements stipulated in Sections
3.4.7.6(k) and 3.4.9.2 (iii) of EIA Study Brief for the feasibility study of
Kai Tak Development and Sections 3.4.7.5(viii) and 3.4.8.2(iii)(a) of EIA Study
Brief No. ESB-159/2006 (for Dredging Works for Proposed Cruise Terminal at Kai
Tak) for the revised dredging extent on 12 June 2007.
Chemical
Testing
6.3.6
Each
sub-sample recovered from the marine SI was tested in the laboratory for the
following parameters:
(i)
Metal
and metalloid concentrations including chromium (Cr), copper (Cu), mercury
(Hg), lead (Pb), cadmium (Cd), nickel (Ni), zinc (Zn), silver (Ag) and arsenic
(As);
(ii)
Concentrations
of organic compounds including total polychlorinated biphenyls (PCBs),
polyaromatic hydrocarbons (PAHs); and
(iii)
Concentration
of tributyltin (TBT) in interstitial water.
6.3.7
Elutriate
tests were conducted to assess the likelihood of release of contaminants from
sediment to the water, when the seabed is disturbed during dredging. If the contaminant levels are higher in
the elutriates in comparison with the sample of marine water from the same
site, it can be concluded that the contaminants are likely to be released into
the open waters during dredging activities. The potential water quality impacts
associated with the dredging of sediment are discussed in Section 5 of
this Report.
6.3.8
Under
the management and classification system, dredged sediments destined for marine
disposal are classified according to their level of contamination by 13
contaminants (Table 6.1).
Table 6.1 SedimentQuality
Criteria for the Classification of Sediment
|
Contaminants |
LCEL |
UCEL |
|
Heavy Metal (mg/kg dry weight) |
||
|
Cadmium (Cd) |
1.5 |
4 |
|
Chromium (Cr) |
80 |
160 |
|
Copper (Cu) |
65 |
110 |
|
Mercury (Hg) |
0.5 |
1 |
|
Nickel (Ni) |
40 |
40 |
|
Lead (Pb) |
75 |
110 |
|
Silver (Ag) |
1 |
2 |
|
Zinc (Zn) |
200 |
270 |
|
Metalloid (mg/kg dry weight) |
||
|
Arsenic |
12 |
42 |
|
Organic-PAHs (µg/kg dry weight) |
||
|
PAHs (Low Molecular Weight) |
550 |
3160 |
|
PAHs (High Molecular Weight) |
1700 |
9600 |
|
Organic-non-PAHs (µg/kg dry weight) |
||
|
Total PCBs |
23 |
180 |
|
Organometallics (µg-TBT L-1 in
interstitial water) |
||
|
Tributyltin |
0.15 |
0.15 |
Source: Appendix A of ETWB TCW No. 34/2002
Management of Dredged / Excavated Sediment
Note: LCEL – Lower
Chemical Exceedance Level
UCEL – Upper Chemical
Exceedance Level
6.3.9
Sediments
are categorised with reference to the LCEL and UCEL, as follows:
Category L Sediment
with all contaminant levels not exceeding the LCEL. The material must be dredged,
transported and disposed of in a manner that minimises the loss of contaminants
either into solution or by suspension.
Category M Sediment
with any one or more contaminant levels exceeding the LCEL and 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 Sediment
with any one or more contaminant levels exceeding the UCEL. The material must be dredged and
transported with great care, and must be effectively isolated from the
environment upon final disposal.
6.3.10
In
the case of Category M and Category H contamination, the final determination of
appropriate disposal options, routing and the allocation of a permit to dispose
of material at a designated site will be made by EPD and the Marine Fill
Committee (MFC) in accordance with the ETWB TCW No. 34/2002.
Biological
Testing
6.3.11
For
Category M sediment, Tier III biological screening was carried out to determine
the appropriate disposal methods in accordance with the requirements of ETWB
TCW No. 34/2002:
(i)
a
10‑day burrowing amphipod toxicity test;
(ii)
a
20‑day burrowing polychaete toxicity test; and
(iii)
a
48‑96 hour larvae (bivalve) toxicity test.
6.3.12
The
species used for each type of biological test and the test conditions are
listed in Table 6.2 below.
Table 6.2 TestSpecies
for Biological Testing
|
Test Types |
Species |
Reference Test Conditions* |
|
10‑day burrowing amphipod toxicity test |
Leptocheirus plumulosus |
U.S.EPA (1994) |
|
20‑day burrowing polychaete toxicity test |
Neanthes arenaceodentata |
PSEP (1995) |
|
48‑96 hour
bivalve larvae toxicity test |
Mytilus spp. or
Crassostrea gigas |
PSEP (1995) |
Notes:*
(i)
U.S.EPA (
(ii)
PSEP (
6.3.13
Sediment
samples were characterized by the testing laboratory for ancillary testing
parameters such as pore water salinity, ammonia, TOC, grain size and moisture
content. This provided necessary
information on the general characteristics of the sediment. The test endpoints and decision criteria
are summarized in Table 6.3.
The sediment was deemed to have failed the biological testing if it
failed in any one of the three toxicity tests.
Table 6.3 TestEndpoints and Decision Criteria for Biological
Testing
|
Toxicity test |
Endpoints
measured |
Failure
criteria |
|
10-day amphipod |
Survival |
Mean survival
in test sediment is significantly different (p £ 0.05)1
from mean survival in reference sediment and mean survival in test sediment < 80% of mean
survival in reference sediment. |
|
20-day polychaete |
Dry Weight2 |
Mean dry
weight in test sediment is significantly different (p £ 0.05)1
from mean dry weight in reference sediment and mean dry weight in test sediment < 90% of mean dry weight
in reference sediment. |
|
48-96 hour bivalve larvae |
Normality Survival3 |
Mean normality
survival in test sediment is significantly different (p £ 0.05)1
from mean normality survival in reference sediment and mean normality survival in test
sediment < 80% of mean normality survival in reference sediment. |
1 Statistically significant differences should be determined using
appropriate two-sample comparisons (e.g.,
t-tests) at a probability of p £ 0.05.
2 Dry
weight means total dry weight after deducting dead and missing worms.
3 Normality
survival integrates the normality and survival end points, and measures
survival of only the normal larvae relative to the starting number.
Existing Sediment Characteristics
6.4.1
A
review of the sediment testing results for the samples collected from Sub-area A
during the first phase of the marine SI (i.e. Phase A as stated in the SQR)
indicates that Category H sediment was found at sampling stations A01 to A05,
A10 and A26 due to high contaminant levels of Cu, Ni, Hg and Ag that exceeded
the UCEL of these four metals.
Category M sediment was found at sampling stations A04, A07 to A9, A11,
A15 and A25 due to the contaminants of Hg and PCBs. Out of a total of ninety-eight samples
collected from Sub-area A, seven samples were classified as Category M and
seven samples were classified as Category H, indicating that the sediment
samples were mostly classified as Category L. The results of the sediment quality
analysis, as compared with the sediment quality criteria for the classification
of sediment, are presented in Table 6.4 for those samples with
contaminant levels exceeding the LCEL or UCEL. Please refer to Appendix B of the
Sediment Quality Report as attached in Appendix 6.2 of this EIA report
for a complete and comprehensive summary of sediment chemical screening/
results.
6.4.2
A
review of the sediment testing results for the samples collected from Sub-area
B during the second phase of the marine SI (i.e. Phase B as stated in the SQR)
indicates that Category H sediment was found at sampling stations B02, B03, B21
and B33 due to high contaminant levels of Ag that exceeded the UCEL of this
metal. Category M sediment was
found at sampling stations B01, B23, B26, B31, B37 and B39 due to the
contaminants of Cu, Hg, Ag and PCBs.
Out of a total of sixty-nine samples collected from Sub-area B, six
samples were classified as Category M and five samples were classified as
Category H, indicating that the sediment samples were mostly classified as
Category L. The results of the sediment
quality analysis, as compared with the sediment quality criteria for the
classification of sediment, are presented in Table 6.5 for those samples
with contaminant levels exceeding the LCEL or UCEL. Details of the marine site investigation
and laboratory testing results are provided in Appendix 6.2.
6.4.3
Based on the results of chemical screening under
Agreement No. KDO 01/2006, approximately 15% of the sediment samples were
classified as Category M or H.
Table 6.4 SedimentChemistry
Results Showing Exceedances (from Sub-area A of Marine SI)
|
Station |
Sample
Depth (m) |
Cd mg/kg |
Cr mg/kg |
Cu mg/kg |
Ni Mg/kg |
Pb mg/kg |
Zn mg/kg |
Hg mg/kg |
As mg/kg |
Ag mg/kg |
TBT µgTBT/L |
LPAH µg/kg |
HPAH µg/kg |
PCBs µg/kg |
Category |
Disposal Option |
|
|
From |
To |
||||||||||||||||
|
|
|
UCEL |
4 |
160 |
110 |
40 |
110 |
270 |
1 |
42 |
2 |
0.15 |
3160 |
9600 |
180 |
- |
- |
|
|
|
LCEL |
1.5 |
80 |
65 |
40 |
75 |
200 |
0.5 |
12 |
1 |
0.15 |
550 |
1700 |
23 |
- |
- |
|
A05 |
0.0 |
0.9 |
<0.2 |
26 |
29 |
20 |
110 |
120 |
2.6 |
7.8 |
0.27 |
<0.015 |
110 |
790 |
<3.0 |
H |
Type 2 |
|
A01 |
4.9 |
5.9 |
0.23 |
72 |
22 |
52 |
84 |
160 |
0.28 |
20 |
0.1 |
<0.015 |
<55 |
<170 |
<3.0 |
H |
Type 2 |
|
A03 |
0.0 |
0.9 |
0.5 |
48 |
160 |
18 |
63 |
130 |
0.78 |
6.9 |
2.4 |
<0.015 |
140 |
1400 |
6.8 |
H |
Type 2 |
|
A04 |
0.0 |
0.9 |
0.4 |
48 |
140 |
20 |
54 |
150 |
0.58 |
7.4 |
2.8 |
<0.015 |
90 |
630 |
110 |
H |
Type 2 |
|
A04 |
0.9 |
1.9 |
<0.2 |
25 |
16 |
18 |
74 |
82 |
1.0 |
7.4 |
0.16 |
<0.015 |
81 |
450 |
<3.0 |
M |
* |
|
A08 |
0.0 |
0.9 |
0.23 |
28 |
62 |
14 |
61 |
80 |
0.89 |
6.6 |
0.61 |
<0.015 |
<55 |
<170 |
6 |
M |
* |
|
A07 |
0.0 |
0.9 |
<0.2 |
18 |
18 |
11 |
54 |
63 |
0.74 |
5.7 |
0.21 |
<0.015 |
<55 |
360 |
20 |
M |
* |
|
A11 |
0.0 |
0.9 |
0.36 |
37 |
110 |
17 |
52 |
93 |
0.47 |
6.3 |
1.0 |
<0.015 |
99 |
640 |
89 |
M |
* |
|
A02 |
0.0 |
0.9 |
<0.2 |
24 |
34 |
18 |
88 |
130 |
1.7 |
7.8 |
0.32 |
<0.015 |
<55 |
260 |
<3.0 |
H |
Type 2 |
|
A26 |
0.9 |
1.9 |
<0.2 |
21 |
<7.0 |
43 |
15 |
39 |
<0.05 |
3.9 |
<0.1 |
<0.015 |
<55 |
<170 |
<3.0 |
H |
Type 2 |
|
A10 |
0.0 |
0.9 |
0.94 |
54 |
270 |
23 |
50 |
140 |
0.68 |
6.9 |
2.5 |
<0.015 |
<55 |
640 |
7.5 |
H |
Type 2 |
|
A09 |
0.0 |
0.9 |
<0.2 |
24 |
34 |
14 |
55 |
78 |
0.68 |
7 |
0.34 |
<0.015 |
120 |
1300 |
9.4 |
M |
* |
|
A15 |
0.0 |
0.9 |
<0.2 |
14 |
13 |
10 |
50 |
53 |
0.59 |
5.9 |
<0.1 |
<0.015 |
<55 |
290 |
<3.0 |
M |
* |
|
A25 |
0.0 |
0.9 |
<0.2 |
16 |
21 |
8.6 |
37 |
62 |
0.62 |
4.4 |
0.24 |
<0.015 |
69 |
760 |
3.6 |
M |
* |
Notes:
Shaded Cell = Value exceeded
UCEL; Underlined Cell = Value exceeded LCEL; “<” = below reporting limit
“*”
= to be determined upon completion of biological screening
Category and disposal option follows ETWB TCW No.
34/2002 (Annex B)
Table 6.5 SedimentChemistry
Results Showing Exceedances (fromSub-area B of Marine SI)
|
Station |
Sample
Depth (m) |
Cd mg/kg |
Cr mg/kg |
Cu mg/kg |
Ni Mg/kg |
Pb mg/kg |
Zn mg/kg |
Hg mg/kg |
As mg/kg |
Ag mg/kg |
TBT µgTBT/L |
LPAH µg/kg |
HPAH µg/kg |
PCBs µg/kg |
Category |
Disposal Option |
|
|
From |
To |
||||||||||||||||
|
|
|
UCEL |
4 |
160 |
110 |
40 |
110 |
270 |
1 |
42 |
2 |
0.15 |
3160 |
9600 |
180 |
- |
- |
|
|
|
LCEL |
1.5 |
80 |
65 |
40 |
75 |
200 |
0.5 |
12 |
1 |
0.15 |
550 |
1700 |
23 |
- |
- |
|
B01 |
0.0 |
0.9 |
<0.2 |
21 |
30 |
12 |
66 |
71 |
1.0 |
6.3 |
0.28 |
<0.015 |
140 |
840 |
6.8 |
M |
* |
|
B02 |
0.0 |
0.7 |
0.26 |
40 |
100 |
14 |
65 |
110 |
0.78 |
6.4 |
2.2 |
<0.015 |
<55 |
470 |
120 |
H |
Type 2 |
|
B03 |
0.0 |
0.5 |
0.25 |
39 |
99 |
13 |
37 |
110 |
0.42 |
6.4 |
2.1 |
<0.015 |
100 |
960 |
21 |
H |
Type 2 |
|
B21 |
0.9 |
1.9 |
<0.2 |
21 |
<7 |
14 |
17 |
43 |
<0.05 |
3.4 |
4.6 |
<0.015 |
<55 |
<170 |
<3 |
H |
Type 2 |
|
B23 |
0.0 |
0.9 |
<0.2 |
22 |
51 |
8.4 |
27 |
72 |
0.19 |
3.9 |
1.6 |
<0.015 |
<55 |
<170 |
32 |
M |
* |
|
B26 |
0.0 |
0.4 |
<0.2 |
22 |
64 |
8.6 |
26 |
63 |
0.26 |
3.4 |
1.2 |
<0.015 |
<55 |
<170 |
<3 |
M |
* |
|
B31 |
0.9 |
1.9 |
<0.2 |
12 |
<7 |
7.7 |
16 |
24 |
0.05 |
4.2 |
2.0 |
<0.015 |
<55 |
<170 |
<3 |
M |
* |
|
B33 |
0.0 |
0.9 |
<0.2 |
15 |
<7 |
9.6 |
15 |
30 |
0.10 |
3.5 |
2.2 |
<0.015 |
<55 |
<170 |
<3 |
H |
Type 2 |
|
B33 |
0.9 |
1.9 |
<0.2 |
15 |
<7 |
9.5 |
16 |
27 |
<0.05 |
3.4 |
2.6 |
<0.015 |
<55 |
<170 |
<3 |
H |
Type 2 |
|
B37 |
0.0 |
0.3 |
<0.2 |
26 |
66 |
11 |
32 |
75 |
0.21 |
6.9 |
1.7 |
<0.015 |
<55 |
<170 |
<3 |
M |
|
|
B39 |
0.0 |
0.3 |
<0.2 |
10 |
31 |
4.1 |
37 |
43 |
0.71 |
2.3 |
0.65 |
<0.015 |
<55 |
<170 |
<3 |
M |
* |
Notes:
Shaded Cell = Value exceeded
UCEL; Underlined Cell = Value exceeded LCEL; “<” = below reporting limit
“*”
= to be determined upon completion of biological screening
Category and disposal option follows ETWB TCW No.
34/2002 (Annex B)
6.4.4
Tier
III biological screening was conducted for the Category M sediment samples as
described above. The results of the
biological screening are summarized in Table 6.6 below. A composite test sample was
prepared from samples A08 and A11 since these two samples are continuous in
horizontal profile and of similar depth.
The other Category M samples collected from Sub-area A during the first
phase of marine SI were tested individually. As the Category M samples collected from
Sub-area B during the second phase of marine SI are discrete (i.e. not being
continuous in either horizontal or vertical profile), no composing was arranged
and each sample was tested individually.
Table 6.6 Resultsof
Biological Screening of Category M Samples
|
Vibrocore No. /
Depth |
Amphipod
Test |
Polychaete
Test |
Bivalve
Test |
Result of Biological Screening |
|
A04 0.9
– 1.9m |
Ö |
Ö |
Ö |
Pass |
|
A07 0 –
0.9m |
Ö |
Ö |
Ö |
Pass |
|
A08
& A11 0 –
0.9m |
Ö |
Ö |
Ö |
Pass |
|
A09 0 –
0.9m |
Ö |
Ö |
X |
Fail |
|
A15 0 –
0.9m |
Ö |
X |
X |
Fail |
|
A25 0 –
0.9m |
Ö |
Ö |
Ö |
Pass |
|
B01 0 –
0.9m |
Ö |
X |
X |
Fail |
|
B23 0 -
0.9m |
Ö |
Ö |
X |
Fail
|
|
B26 0 -
0.4m |
Ö |
Ö |
X |
Fail |
|
B31 0.9
- 1.9m |
Ö |
Ö |
Ö |
Pass |
|
B37 0 -
0.3m |
Ö |
Ö |
Ö |
Pass |
|
B39 0 -
0.3m |
Ö |
Ö |
X |
Fail |
Notes:
X =
fail biological test
Ö =
pass biological test
6.5
Identification of Potential Sources of Environmental
Impact
6.5.1
The
construction phase activities to be carried out for the proposed Project would
generate a variety of wastes that can be divided into distinct categories based
on their composition and ultimate method of disposal. The identified waste types include:
l
Marine dredged sediment
l
C&D material
l
Chemical waste
l
General refuse
6.5.2
Each type of waste arising is described below, together with an
evaluation of the potential environmental impacts associated with the
generation, handling, storage and transport of the waste.
6.6
Prediction and Evaluation of Environmental Impacts
Dredged Marine Sediment
Capital
Dredging During Construction Phase
6.6.1
The
initial capital dredging for the manoeuvring basin for operation of the Phase I
Berth and the Phase II Berth of the proposed cruise terminal should allow for
dredging to -12mCD. The existing
seabed levels within the dredging area are based on the bathymetric survey
carried out under Agreement No. KDO 01/2006 “Site Investigation and Contaminated
Assessment at Remaining Area of
6.6.2
The
chemical and biological screening results presented in Section 6.4 above
identified the locations and the corresponding depths of the contaminated
sediment. The disposal options for
the identified contaminated sediment as determined in accordance with ETWB TCW
No. 34/2002 are summarised in Table 6.7 below.
Table 6.7 DisposalOptions
for the Identified Contaminated Sediment
|
Type 1 – |
||||
|
Type 1 – |
||||
|
Type 1 – |
||||
|
Type 1 – |
||||
|
Type 1 – |
||||
|
0.7 |
||||
|
Type 1 – |
||||
|
Type 1 – |
||||
6.6.3
The
volume of contaminated sediment within the dredging area for the manoeuvring
basin of the Phase I Berth and the Phase II Berth is estimated based on the
sediment testing results summarized above in Table 6.7. The locations of contaminated sediment
are represented by grab or vibrocore sampling stations. The estimation is undertaken to
determine the volume of contaminated sediment to be dredged taking into account
the proposed dredging area and the dredging depth profile.
6.6.4
The
potential extent of the identified contaminated sediment are shown in Figure 6.1. The volume of sediment requiring
different disposal options in accordance ETWB TCW No. 34/2002 are summarised in
Table 6.8 below.
Table 6.8 Volumeof
Sediment Requiring Different Disposal
Options (in m3)
|
Type 1 – |
||
|
Type 1 – |
||
Note: All
materials to be generated from the removal of the existing seawall for berth
construction are expected to be C&D material (i.e. no sediment would be
generated from the removal of the existing seawall).
Maintenance
Dredging During Operational Phase of the Proposed Cruise Terminal
6.6.5
It
is assumed that the siltation rate will be in the order of 100mm per year
(refer to Section 2.7). As such up
to 500mm of sediment will need to be dredged every 5 to 10 years. Given that the area needed for
manoeuvring of vessels is approximately 700,000 m2, then this represents a dredged
volume of approximately 350,000 m3 every 5 to 10 years.
6.6.6
As discussed in Section 2.7, there would be a long
term improvement in the sediment quality of the manoeuvring area. In any case, maintenance dredging would
require sediment sampling and testing in accordance with the requirements of
the ETWB TCW No. 34/2002 for proper disposal of the uncontaminated and
contaminated dredged sediment. Marine Fill Committee (MFC) would
determine the most appropriate open sea or confined marine disposal site on the
basis of the chemical and biological test results and formally allocate marine
disposal space in accordance with the ETWB TCW No. 34/2002. Therefore, no
adverse waste impact from maintenance dredging would be expected.
Dredging,
Transportation and Disposal
6.6.7
To
minimise any potential adverse impacts arising from the dredged marine
sediment, the sediment should be dredged, transported and disposed of in a
manner that would minimise the loss of contaminants either into solution or by
resuspension.
6.6.8
As
discussed in Section 3, the dredging activities are marine based activities and
negligible dust impacts on nearby air sensitive receivers would be
expected. Besides, it is expected
that the potential odour emissions from the sediments within the dredging area
of the proposed cruise terminal would be minimal and adverse odour impact from
the capital and maintenance dredging activities and the associated
transportation and disposal would not be anticipated.
6.6.9
The
findings of the noise impact assessment presented in Section 4 of this report
indicated that adverse noise impact would not be expected during the course of
the capital and maintenance dredging activities.
6.6.10
Mitigation
measures to minimise potential environmental impacts are recommended in Section
6.7. With the implementation of the
recommended mitigation measures, no unacceptable impacts would be expected from
the dredging, transportation and disposal of the dredged sediment.
Construction and Demolition Material
6.6.11
C&D
material would be generated from the removal of a section of the existing
seawall by dredging at the southern tip of the former
6.6.12
It is assumed all the C&D material generated from
the Project would require off-site disposal. Seawall construction relies very heavily on the grading of materials.
If the materials are not graded properly then there is the risk that the
reclamation will wash out through the seawall and the seawall will collapse.
Whilst the as-built drawings of the existing runway seawalls and reclamations
have been obtained they do not give any information as to the grading of the
existing materials. As such it is not possible with the information available
to make any accurate assessment as to which materials may be suitable for
reuse. As such a conservative estimate has been made for the purpose of the
EIA.
6.6.13
Nevertheless,
the contractor for capital dredging should investigate the potential for
reusing the C&D materials on site. If practical, the C&D material
generated from the Project should be sorted and any unsuitable material removed
to achieve the correct grading for seawall construction. In other words, it may
be possible that the existing material could be blended with other new material
to achieve the required grading for seawall construction.
6.6.14
The C&D material to be disposed off-site
should be transported and handled in a manner that would minimise the
disturbance to the environment.
Mitigation measures to minimise potential environmental impacts are
recommended in Section 6.7. With
the implementation of the recommended mitigation measures, no unacceptable
impacts would be expected from the transportation and disposal of the C&D
material.
6.6.15
With regard to the material to be
generated from the removal of the abandoned Kai Tak Runway submarine outfall,
much of the material will be removed by grab dredger, using marine plant, with
no clear view of what is being picked up the grab underwater. As such the
material being loaded into the barge will be a mixture of rubble and marine
mud. It is not practical to assume that these materials can be separated during
the dredging process. Dredging works for removal of the abandoned Kai Tak
Runway submarine outfall will be incorporated into the Stage 1 dredging works
and all material generated from the outfall removal would be disposed off-site
as marine sediments.
Chemical Waste
6.6.16
The
maintenance and servicing of construction plant and equipment may generate some
chemical wastes such as cleaning fluids, solvents, lubrication oil and
fuel. It is difficult to quantify
the amount of chemical waste that will arise from the construction activities
since it will be dependent on the contractor’s maintenance requirements and the
amount of plant utilised. However,
it is anticipated that the quantity of chemical waste, such as lubricating oil
and solvent produced from plant maintenance, would be small and in the order of
a few cubic metres per month during both capital and maintenance dredging. The amount of chemical waste to be
generated will be quantified in the site Waste Management Plan to be prepared
by the contractor.
6.6.17
Chemical
wastes arising during the construction phase may pose environmental, health and
safety hazards if not stored and disposed of in an appropriate manner as
stipulated in the Waste Disposal (Chemical Waste) (General) Regulations. The potential hazards include:
l
Toxic effects to workers
l
Adverse impacts on water quality from spills
l
Fire hazards
6.6.18
Materials
classified as chemical wastes will require special handling and storage
arrangements before removal for appropriate treatment at the Chemical Waste
Treatment Facility (CWTF) or other licensed facility. Wherever possible, opportunities should
be taken to reuse and recycle materials.
Mitigation and control requirements for chemical wastes are detailed in
Section 6.7. Provided that the
handling, storage and disposal of chemical wastes are in accordance with these
requirements, adverse environmental impacts would not be expected to result.
General Refuse
6.6.19
The
workforce to be involved in the capital and maintenance dredging would generate
general refuse comprising food scraps, waste paper, empty containers, etc. Release of general refuse into the
marine water or surface channel should not be permitted as introduction of
these wastes is likely to have detrimental effects on water quality in the
area. Rapid and effective
collection of site wastes would be required to prevent waste materials being
blown around by wind, flushed or leached into the aquatic environment, and
odour nuisance. The work sites may
also attract pests and vermin if the waste storage area is not well maintained
and cleaned regularly. Disposal of
refuse at sites other than approved waste transfer or disposal facilities can
also result in similar impacts.
6.6.20
With
the implementation of the recommended waste management practices at the site, adverse
environmental impacts are not expected to arise from the storage, handling and
transportation of refuse.
6.7
Mitigation of Environmental Impacts
Good Site Practices
Ÿ
Nomination of an approved person, such as a site
manager, to be responsible for good site practices, arrangements for collection
and effective disposal to an appropriate facility, of all wastes generated at
the site.
Ÿ
Training of site personnel in proper waste management
and chemical waste handling procedures.
Ÿ
Provision of sufficient waste disposal points and
regular collection for disposal.
Ÿ
Appropriate measures to minimise windblown litter and
dust during transportation of waste by either covering trucks or by
transporting wastes in enclosed containers.
Ÿ
A recording system for the amount of wastes generated,
recycled and disposed of (including the disposal sites).
Waste Reduction Measures
6.7.2
As discussed in Section 2.6 of this EIA report, the
proposed location for the cruise terminal at the runway tip has the deepest
seabed along the former runway and larger manoeuvring space for receiving mega
cruise vessels. The access from and
to the main fairway is also a very direct one. The proposed location for the cruise
terminal has thus minimised the extent seabed dredging and hence reduce the
volume of dredge sediment generated from the Project.
6.7.3
Besides, the proposed size and configuration of the
manoeuvring areas for the cruise terminal was reviewed using real time vessel
simulations to be the
minimum essential to provide space needed for safe manoeuvring of cruise vessels
clear of the fairway and cruise berth.
6.7.4
With regards to the berth structure, also discussed in
Section 2.6, amongst the three feasible options namely Option 1 (Piled Quay
Deck), Option 2 (Precast Reinforced Concrete Caisson) and Option 3 (Precast
Concrete Blockwork Seawall), the piled quay deck (Option 1) would require the
least amount of dredging at the existing seawall during construction. In environmental terms the main difference
between Options 1, 2, and 3 is the volume of dredging from the existing seawall. It should be noted that the volume of
dredging from the existing seawall is comparatively less in the case of Option
1, therefore the allowance for Options 2 and 3 in this EIA represents a worst
case assumption (refer to Table 2.2).
6.7.5
On dredging method, closed grab dredgers are
considered as the most suitable dredgers for relatively small volumes and
contaminated mud. It is feasible to
use small trailer suction dredgers but these will give less control over
handling of contaminated mud and produce more marine sediment by volume (due to
high water content) when compared with grab dredging. Whilst larger equipment has been adopted
for major reclamation projects such as the Penny’s Bay reclamation and Container
Terminals in Kwai Chung, in this case, given that dredging is not on the
critical programme path, it is assumed that the most cost effective
construction method with the least environmental impact including the
production of least dredge sediment will be adopted for the cruise terminal
i.e. closed grab dredgers.
6.7.6
Apart from the planning and design measures on waste
reduction described above, good management and control can also prevent the
generation of a significant amount of waste. Waste reduction is best achieved at the
planning and design stage, as well as by ensuring the implementation of good
site practices. Recommendations to
achieve waste reduction include:
Ÿ
Segregation and storage of different types of waste in
different containers, skips or stockpiles to enhance reuse or recycling of
materials and their proper disposal.
Ÿ
Encourage collection of aluminium cans, PET bottles
and paper by providing separate labelled bins to enable these wastes to be
segregated from other general refuse generated by the work force.
Ÿ
Any unused chemicals or those with remaining
functional capacity shall be recycled.
6.7.7
In addition to the above measures, specific mitigation
measures are recommended below for the identified waste arisings to minimise
environmental impacts during handling, transportation and disposal of these
wastes.
Dredged Marine Sediment
6.7.8
The
basic requirements and procedures for dredged mud disposal are specified under
the ETWB TCW No. 34/2002. The
management of the dredging, use and disposal of marine mud is monitored by the
MFC, while the licensing of marine dumping is required under the Dumping at Sea
Ordinance and is the responsibility of the Director of Environmental Protection
(DEP).
6.7.9
The
dredged marine sediments would be loaded onto barges and transported to the
designated disposal sites allocated by the MFC depending on their level of
contamination. Sediment classified
as Category L would be suitable for Type 1 - Open Sea Disposal. Contaminated sediment would require
either Type 1 – Open Sea Disposal (Dedicated Sites) or Type 2 - Confined Marine
Disposal and must be dredged and transported with great care in accordance with
ETWB TCW No. 34/2002.
Subject to the final allocation of the disposal sites by MFC, the
dredged contaminated sediment must be effectively isolated from the environment
upon final disposal and shall be disposed of at the East Sha Chau Contaminated
Mud Pits that are designated for the disposal of contaminated mud in
6.7.10
It
will be the responsibility of the contractor to satisfy the appropriate
authorities that the contamination levels of the marine sediment to be dredged
have been analysed and recorded.
According to the ETWB TCW No. 34/2002, this will involve the submission
of a formal Sediment Quality Report to the DEP, prior to the dredging contract
being tendered. The contractor for the dredging works shall
apply for allocation
of marine disposal sites and all necessary permits from relevant authorities
for the disposal of dredged sediment.During transportation and disposal of the dredged marine sediments
requiring Type 1 and Type 2 disposal, the following measures should be taken to
minimise potential impacts on water quality:
l
Bottom opening of barges shall be fitted with
tight fitting seals to prevent leakage of material. Excess material shall be cleaned from
the decks and exposed fittings of barges and hopper dredgers before the vessel
is moved.
l
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 required
under the Dumping at Sea Ordinance and as specified by the DEP.
l
Barges or hopper barges shall not be filled to a
level that would cause the overflow of materials or sediment laden water during
loading or transportation.
6.7.11
Negligible
dust impacts would be expected from dredging activities. In order to further ensure compliance
with the Air Quality Objectives at the air sensitive receivers, requirements of
the Air Pollution Control (Construction Dust) Regulation, where relevant, shall
be adhered to during the construction period of the Project. The dredged sediment placed on barge
should be properly covered as far as practicable to minimise the potential
odour emissions during the dredging operation and transportation of the dredged
sediment.
6.7.12
In order to further ameliorate the noise impacts
associated with the capital and maintenance dredging activities, good site
practices listed below should be adopted by all the contractors as far as
practicable:
l
Only
well-maintained plant should be operated on-site and plant should be serviced
regularly during the construction program.
l
Mobile
plant, if any, should be sited as far away from nearby noise sensitive
receivers as possible.
l
Machines
and plant (such as trucks) that may be in intermittent use should be shut down
between works periods or should be throttled down to a minimum.
l
Plant
known to emit noise strongly in one direction should, wherever possible, be
orientated so that the noise is directed away from nearby noise sensitive
receivers.
l
Material
stockpiles and other structures should be effectively utilised, wherever
practicable, in screening noise from on-site construction activities.
Construction and Demolition Material
6.7.13
It
is recommended that the extent of dredging of the existing seawall should be
kept to a minimum in the detailed design of the new cruise terminal to minimize
generation of C&D material.
Mitigation measures and good site practices should be incorporated in
the contract document to control potential environmental impact from handling
and transportation of C&D material.
The mitigation measures include:
Ÿ
Where
it is unavoidable to have transient stockpiles of C&D material within the
Project work site pending collection for disposal, the transient stockpiles
shall be located away from waterfront or storm drains as far as possible.
Ÿ
Open stockpiles of construction materials or
construction wastes on-site should be covered with tarpaulin or similar fabric.
Ÿ
Skip hoist for material transport should be totally
enclosed by impervious sheeting.
Ÿ
Every vehicle should be washed to remove any dusty
materials from its body and wheels before leaving a construction site.
Ÿ
The area where vehicle washing takes place and the
section of the road between the washing facilities and the exit point should be
paved with concrete, bituminous materials or hardcores.
Ÿ
The load of dusty materials carried by vehicle leaving
a construction site should be covered entirely by clean impervious sheeting to
ensure dust materials do not leak from the vehicle.
Ÿ
All dusty materials should be sprayed with water prior
to any loading, unloading or transfer operation so as to maintain the dusty
materials wet.
Ÿ
The height from which excavated materials are dropped
should be controlled to a minimum practical height to limit fugitive dust
generation from unloading.
6.7.14
When
delivering inert C&D material to public fill reception facilities, the
material shall consist entirely of inert construction waste and of size less
than 250mm or other sizes as agreed with the Secretary of the Public Fill
Committee. In order to monitor the
disposal of the surplus C&D material at the designed public fill reception
facility and to control fly tipping, a trip-ticket system as stipulated in the
ETWB TCW No. 31/2004 “Trip Ticket System for Disposal of Construction and
Demolition Materials” should be included as one of the contractual requirements
and implemented by an Environmental Team undertaking the Environmental
Monitoring and Audit work. An
Independent Environmental Checker should be responsible for auditing the
results of the system.
Chemical Waste
6.7.15
After
use, chemical wastes (for example, cleaning fluids, solvents, lubrication oil
and fuel) should be handled according to the Code of Practice on the
Packaging, Labelling and Storage of Chemical Wastes. Spent chemicals should be collected by a
licensed collector for disposal at the CWTF or other licensed facility, in
accordance with the Waste Disposal (Chemical Waste) (General) Regulation.
General Refuse
6.7.16
General refuse should be stored in enclosed bins or
compaction units separate from C&D material. A reputable waste collector should be
employed by the contractor to remove general refuse from the site, separately
from C&D material. An enclosed
and covered area is preferred to reduce the occurrence of 'wind blown' light
material.
6.7.17
Table 6.9 provides
a summary of the various waste types likely to be generated during the
construction phase, together with the recommended handling and disposal
methods.
Table
6.9 Summaryof
Waste Handling Procedures and Disposal Routes
|
Waste Type |
Generated from Works Item |
Total Quantity Generated |
Quantity to be disposed off-site / re-used |
Handling |
Disposal |
|
Capital Dredging |
|||||
|
C&D Material |
Removal of existing seawall by dredging |
322,300 m3 rock fill / rock armour / general fill |
322,300 m3 of C&D material to be
disposed off-site C&D material should be reused as far as
practicable |
Dust and water quality mitigation measures (Sections 6.7.14 – 6.7.15) |
Inert C&D material to be disposed off-site
to the designated public fill reception facility C&D material should be reused as far as
practicable |
|
Dredged Sediment |
Dredging of seabed in the proposed manoeuvring
basin (Category H and Category M sediment) |
430,000 m3 Stage 1: 210,000 m3 & Stage 2: 220,000m3 |
430,000 m3 (Stage 1: 210,000m3 & Stage 2:
220,000m3) |
Dust, odour, noise , water quality mitigation
measures (Sections 6.7.8 – 6.7.13) |
Type 1 – |
|
Dredging of seabed in the proposed manoeuvring
basin (Category L sediment) |
950,000 m3 Stage 1: 490,000m3 (including 20,000m3 from removal of
the Kai Tak Runway submarine outfall) & Stage 2: 460,000m3 |
950,000 m3 (Stage 1: 490,000m3 & Stage 2:
460,000m3) |
Type 1 - Open Sea Disposal - gazetted marine
disposal ground allocated by MFC |
||
|
Removal of existing seawall by dredging |
None |
None |
- |
- |
|
|
Chemical Wastes |
Cleansing fluids, solvent, lubrication oil and
fuel from construction plant and equipment |
Few cubic metres per month (preliminary
estimate) |
Few cubic metres per month (preliminary
estimate) |
Recycle by licensed companies Stored on-site within suitably designed
containers (Section 6.7.16) |
Chemical Waste Treatment Facility or other
licensed facility |
|
General Refuse |
Waste paper, discarded containers, etc.
generated from workforce |
Approx. 13 kg per day (preliminary estimate
based on workforce of 20) |
Approx. 13 kg per day |
Provide on-site refuse collection points
(Section 6.7.17) |
Refuse station for compaction and
containerisation and then to landfill |
|
Maintenance Dredging |
|||||
|
Dredged Sediment |
Sediment quality to be determined by sediment sampling and testing
under the requirements of the ETWB TCW No. 34/2002 |
Approx. 350,000 m3 every 5 to 10 years |
Approx. 350,000 m3 every 5 to 10 years |
Dust, odour, noise , water quality mitigation
measures (Sections 6.7.8 – 6.7.13) |
MFC would formally allocate marine disposal space in accordance with
ETWB TCW No. 34/2002. |
|
Chemical Wastes |
Cleansing fluids, solvent, lubrication oil and
fuel from construction plant and equipment |
Few cubic metres per month (preliminary
estimate) |
Few cubic metres per month (preliminary
estimate) |
Recycle by licensed companies Stored on-site within suitably designed
containers (Section 6.7.16) |
Chemical Waste Treatment Facility or other
licensed facility |
|
General Refuse |
Waste paper, discarded containers, etc.
generated from workforce |
Approx. 13 kg per day (preliminary estimate
based on workforce of 20) |
Approx. 13 kg per day |
Provide on-site refuse collection points
(Section 6.7.17) |
Refuse station for compaction and
containerisation and then to landfill |
6.8
Evaluation of Residual Environmental Impacts
6.8.1
With
the implementation of the recommended mitigation measures for the handling,
transportation and disposal of the identified waste arisings, no residual
impact is expected to arise during the proposed capital dredging during
construction stage and maintenance dredging during operational stage of the
proposed cruise terminal.
6.9.1
Waste
management will be the contractor’s responsibility to ensure that all wastes
produced during the dredging operation are handled and disposed of in
accordance with the recommended mitigation measures and EPD’s regulations and
requirements. The mitigation
measures recommended in Section 6.7 above should form the basis of the site
Waste Management Plan to be developed by the contractor in the construction and
operational stages of the propose cruise terminal.
6.10.1
The
total volume of dredged sediment generated from the dredging of the seabed to
provide the manoeuvring basin for the cruise terminal is estimated to be
approximately 1.38 Mm3 during construction phase. Based on the results of the chemical and
biological screening, approximately 430,000 m3 was classified as
contaminated dredged sediment (Category M and H) requiring Type 1 – Open Sea
Disposal (Dedicated Sites) or Type 2 - Confined Marine Disposal, and
approximately 950,000 m3 was classified as Category L sediment
suitable for Type 1 - Open Sea Disposal in accordance with ETWB TCW
No. 34/2002.
6.10.2
The
total volume of dredged sediment generated from maintenance dredging during
operational phase is estimated to be approximately 350,000 m3 every 5 to 10 years. Prior to any maintenance dredging,
sediment sampling and testing will be carried out in accordance with the ETWB
TCW No. 34/2002 to determine the contamination level of the dredged
sediment. The most appropriate open sea or confined marine disposal site will
be allocated for proper disposal of the dredged sediment on the basis of the
chemical and biological test results in accordance with the ETWB TCW No.
34/2002.
6.10.3
The
total volume of C&D material generated from the removal of the existing
seawall by dredging for the berth construction is estimated to be approximately
322,300 m3 during construction phase. No C&D material would be generated
from maintenance dredging during operational stage of the proposed cruise
terminal. Other wastes generated from
the capital and maintenance dredging are likely to include chemical waste from
the maintenance of construction plant and equipment and general refuse from the
construction workforce.
6.10.4 Mitigation measures are recommended in this EIA to minimise potential environmental impacts associated with handling and disposal of different wastes arising from the Project. Provided that the recommended mitigation measures are properly followed, adverse environmental impacts would not be expected from the capital and maintenance dredging.