6 WASTE
management.. 2
6.1 Introduction. 2
6.2 Environmental Legislation, Policies,
Plans, Standards and Criteria. 2
6.3 Assessment Methodology. 3
6.4 Baseline Conditions. 3
6.5 Identification of Potential Sources
of Impact 3
6.6 Prediction and Evaluation of
Environmental Impacts. 3
6.7 Mitigation Measures. 3
6.8 Evaluation of Residual Impacts. 3
6.9 Environmental Audit 3
6.10 Conclusion. 3
6
WASTE management
6.1.1
This
section identifies the types of solid wastes that are likely to be generated
from the temporary typhoon shelter (DP4) and evaluates the potential
environmental impacts that may result from these wastes. Mitigation measures and good site
practices, including measures for waste handling, storage and disposal, are
recommended with reference to the applicable waste legislation and
guidelines.
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:
·
Waste Disposal Ordinance
(Cap. 354)
·
Waste Disposal (Chemical
Waste) (General) Regulation (Cap. 354)
·
Land (Miscellaneous
Provisions) Ordinance (Cap. 28)
·
Public Health and Municipal
Services Ordinance (Cap. 132) - Public Cleansing and Prevention of Nuisances
Regulation
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 &
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.
6.2.11
Measures have been introduced
under Environment, Transport and Works Bureau (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.
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 follow
those presented in Annex 15 of the EIAO-TM and include the following:
·
Estimation of the types and
quantities of the wastes generated.
·
Assessment of potential
impacts from the management of solid waste with respect to potential hazards,
air and odour emissions, noise, wastewater discharge and transport.
·
Assessment of impacts on the
capacity of waste collection, transfer and disposal facilities.
Dredged Marine Sediment
6.3.1
The
Phase I marine site investigation works of WDII commenced on 25 August 2006 and
were completed on 14 September 2006 and included laboratory testing of
contaminants to determine the level of contamination in the marine sediments at
the proposed reclamation. The works
included vibrocoring in the HKCEC sea channel, the Causeway Bay
typhoon shelter, North Point waterfront and the proposed temporary typhoon
shelter to obtain sediment samples for chemical testing (Figure 6.1). The Phase II marine site investigation
works commenced on 27 September 2006 and were completed on 10 October 2006 and
included sampling locations to the west and east of the HKCEC and in the
Wanchai Public Cargo Working Area (PCWA) basin (Figure 6.1). Permission to sample in the WSD
prohibition zone and MTR protection zone in the area to the west of HKCEC was
not obtained from WSD and MTRC for the Phase II marine site investigation. In addition, MTRC advised that anchoring
is not permitted within 20m of their protection zone and hence it was not
possible to carry out sampling at the proposed locations.
Chemical Testing
6.3.2
Each
sub-sample recovered from the Phase I and II vibrocoring 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)
6.3.3
Grab
samples collected from the vibrocoring locations were tested for tributyltin
(TBT) in interstitial water. Grab
samples were used in view of the difficulty to extract sufficient interstitial
water for the TBT analysis in the vibrocore samples to achieve the required
detection limit, as was encountered in the EIA study for Wan Chai Development
Phase II Comprehensive Feasibility Study.[1]
6.3.4
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.
6.3.5
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 Sediment Quality
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
6.3.6
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.
6.3.7
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
6.3.8
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
(iii)
a 48‑96 hour larvae
(bivalve) toxicity test.
6.3.9
Sediment
classified as Category H with one or more contaminant levels exceeding 10 times
the LCEL were also subjected to the above three biological tests but in a
diluted manner (dilution test).
6.3.10
The
species used for each type of biological test and the test conditions are
listed in Table 6.2 below.
Table 6.2 Test Species 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 (U.S. Environmental Protection Agency)
1994. Methods for assessing the
toxicity of sediment-associated contaminants with estuarine and marine
amphipods. Office of Research and
Development. U.S.
Environmental Protection Agency, Cincinnati,
OH. EPA/600/R94/025.
(ii)
PSEP (Puget
Sound Estuary Program) 1995. Recommended guidelines for conducting
laboratory bioassays on Puget Sound sediments.
6.3.11
Sediment
samples were characterized by the testing laboratory for ancillary testing
parameters such as porewater 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 Test Endpoints 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
The
results of the marine sediment quality analysis from the Phase I and Phase II marine
site investigation works, as compared with the sediment quality criteria for
the classification of sediment, are presented in Appendix 6.1. All
testing results of TBT in interstitial water were below the reporting limit of
0.015 µg/L. The practical limitation of being unable
to carry out the TBT interstitial water test is therefore not considered to
have any significant effect.
6.4.2
At
the proposed temporary typhoon shelter, the sediment testing results indicate
that Category H sediment was found at all but three of the eight vibrocoring
locations due to high contaminant levels of Cu, Hg and Ag. At V06-44, Category H sediment with the
contaminant level of Hg exceeding the LCEL by 10 times was reported. Category L
and M sediment was found at V06-41, V06-42 and V06-46.
6.4.3
Tier
III biological screening was conducted for the Category M sediment samples
(found at V06-41, V06-42 and V06-44), and the Category H sediment samples
(found at V06-44) with the reported contaminant levels exceeding the LCEL by 10
times i.e. >10xLCEL, as described above. The results of the biological screening
are summarized in Table 6.4 below.
Table 6.4 Results
of Biological Screening of Category M and Category H (>10xLCEL) Samples
Vibrocore No. /
Depth
|
Location
|
Amphipod Test
|
Polychaete Test
|
Bivalve Test
|
Result of
Biological Screening
|
Classification
|
V06-41 0-0.9m
|
Temporary breakwater
|
Ö
|
Ö
|
Ö
|
Pass
|
Category M
|
V06-42 0-0.9m
|
Temporary breakwater
|
Ö
|
Ö
|
Ö
|
Pass
|
Category M
|
V06-44 0-0.9m
|
Temporary breakwater
|
Ö
|
Ö
|
X
|
Pass *
|
Category H
|
V06-44 0.9-2.9m
|
Temporary breakwater
|
Ö
|
Ö
|
Ö
|
Pass
|
Category M
|
Notes:
1.
X = fail biological test
2.
Ö = pass biological
test
3.
* = high levels of unionized ammonia in overlying
water of 0.21 mg/L reported at test termination of the bivalve test. The laboratory test report stated
“results could be qualified as possible false positive when ammonia (unionized)
is greater than 0.13 mg/L”. This
sample is therefore not classified as failing the biological screening.
4.
** = sample failed biological screening and therefore
would require Type 3 special disposal.
6.5.1
The
construction activities to be carried out for the proposed temporary typhoon
shelter 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:
·
Marine dredged sediment
·
C&D material
·
Chemical waste
·
General refuse
6.5.2
Another
identified waste type within the project area is floating refuse. It should be noted that floating refuse
in Victoria Harbour is an existing waste and the
project itself is not designed to generate floating refuse. Since the project
area is in the vicinity or within Victoria
Harbour, some refuse and
debris may be unintentionally brought from the site into the harbour during
heavy rains or typhoons. Nevertheless, it is considered that the quantity of
floating refuse generated from this situation would be limited.
6.5.3
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.
Dredged Marine Sediment
6.6.1
The
seabed would be dredged for the temporary breakwater construction. The total volume of dredged sediment for
the temporary breakwater is estimated to be approximately 0.118Mm3. Based on the results of the chemical and
biological screening, the estimated volume of contaminated dredged sediment
(Category M and H) requiring Type 2 confined marine disposal is approximately
0.07 Mm3, and the estimated volume of Category L sediment
suitable for open sea disposal is approximately 0.048 Mm3. 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.
6.6.2
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. Mitigation measures
to minimise potential environmental impacts are recommended in Section
6.7. Since the dredging activities
are marine based activities and negligible dust impacts on nearby air sensitive
receivers would be expected. 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 dredging activities.
6.6.3
Mitigation
measures to minimise potential environmental impacts are recommended in Section
6.7. With the implementation of mitigation measures, no unacceptable impacts
would be expected from the transportation and disposal of the dredged sediment.
Construction and Demolition Materials
6.6.4
Demolition
material will be generated from the removal of the temporary breakwater formed
for the temporary typhoon shelter.
Based on the preliminary construction programme, the removal of the
temporary typhoon shelter breakwater is scheduled to take place in late
2015. The estimated volume of
demolition material from removal of the temporary typhoon shelter breakwater is
approximately 0.156 Mm3.
6.6.5
The
amount of C&D material expected to be generated will be quantified in the
site Waste Management Plan to be prepared by the Contractor. Since the construction activities will
be located near the waterfront, improper management of C&D materials may
introduce debris and pollutants to the harbour waters, and mitigation measures
will be required (refer to Section 6.7).
6.6.6
Demolition
material will arise from the removal of the temporary breakwater formed for the
temporary typhoon shelter and will comprise primarily concrete. It is assumed that approximately 95% of
the C&D material will be public fill and the other will be C&D
waste. Suitable (inert) material
should be broken down to 250 mm
in size for reuse as public fill in the WDII reclamation (for filling from +2.5
mPD to the formation level and use as surcharge). By reducing the quantity of C&D
material requiring off-site disposal, the potential for environmental impacts
from the transportation of material by road will also be reduced (such as noise
impacts, possible congestion due to increased traffic flows, and dust and
exhaust emissions from the haul vehicles).
It is recommended that C&D material should be transported from the
site by barge wherever possible to reduce impacts from road
transportation. The disposal of surplus
public fill by dump trunks would be considered as the last resort. The estimated volume of C&D material
generated from the removal of the temporary breakwater is around 0.156 Mm3 of rock material
that will require off-site disposal to public fill reception facilities. It
should be noted that since the removal of the temporary breakwater can only be
demolished at the very late stage of the Project when all of the reclamation
works have been completed, the C&D material generated from this demolition activities
could not be reused on site.
Chemical Waste
6.6.7
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 on-site 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. The
amount of chemical waste to be generated will be quantified in the site Waste
Management Plan to be prepared by the Contractor.
6.6.8
Chemical
wastes arising during the construction phase may pose environmental, health and
safety hazards if not stored and disposed of in an appropriate manner as
stipulated in the Waste Disposal (Chemical Waste) (General) Regulations. The potential hazards include:
·
Toxic effects to workers
·
Adverse impacts on water
quality from spills
·
Fire hazards
6.6.9
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
6.6.10
The
construction workforce would generate general refuse comprising food scraps,
waste paper, empty containers, etc.
As the introduction of these wastes is likely to
have detrimental effects on water quality in the area, such refuse should be
properly managed so intentional or accidental release to the surrounding
environment does not occur.
Disposal of refuse at sites other than approved waste transfer or
disposal facilities shall be prohibited.
Effective collection of site wastes would be required to prevent waste
materials being blown around by wind, flushed or leached into the marine
environment, or creating an odour nuisance. The waste storage area should be
well maintained and cleaned regularly so as to prevent from attracting pests
and vermin to the work sites.
6.6.11
The
maximum number of construction workers to be employed is estimated to be about
40 workers. Based on a generation
rate of 0.65 kg per worker per day, the maximum daily arising of general refuse
during the construction period would be approximately 26 kg. With the implementation of waste
management practices at the site (as recommended in Section 6.7), adverse
environmental impacts would not be expected from the storage, handling and
transportation of refuse.
Floating Refuse
6.6.12 Floating
refuse in Victoria
Harbour is an existing
waste. The record of floating refuse collected by
Marine Department’s contractor within the project area is shown in Table 6.5 below. The data indicates a decreasing trend in
the quantity of floating refuse collected.
During the reporting period, approximately 31% to 42% of the refuse
within the project area was collected within the Causeway Bay Typhoon
Shelter. The quantity of floating
refuse collected was higher in the summer months which may be attributed to the
heavy rains and typhoons bringing more refuse into the harbour. In the summer, the
wind direction is from the south-west which also brings more refuse into the
harbour.
6.6.13
Floating
refuse, if not collected, may drift along the waterfront, which may create
aesthetic impact. In view of the project design, the Project itself is not
designed to generate floating refuse. Considering that the project area is in
the vicinity or within Victoria
Harbour, some refuse and
debris may be unintentionally brought from the site into the harbour during
heavy rains or typhoons. However, it is expected that the quantity of floating
refuse generated from this situation would be limited. Given that the proposed
reclamation is designed with streamlined shoreline, the potential floating
refuse problem would be minimized.
Furthermore, with the implementation of the control measures in Section
6.7, the accumulation of floating refuse during construction phase would be
avoided/minimized. Since the Project would not worsen the shoreline
configuration and the implementation of appropriate control measures during
construction phase, it is considered that the future quantity of refuse to be
found along the shoreline would be similar if not better than the existing
situation.
6.6.14 Specialised refuse collection
vessels currently operate in Victoria
Harbour to provide a
refuse scavenging and collection service under the responsibility of the
Pollution Control Unit of Marine Department (MD). During the construction phase, the
project proponent’s contractor will be responsible for the collection of any
refuse within their works area. With the implementation of the refuse
collection system properly within the project area, no insurmountable
environmental impact with regard to floating refuse would be anticipated during
the construction phase.
Table 6.5 Record of Floating
Refuse Collected within the Project Area
Area
|
Jul 05
|
Aug 05
|
Sep 05
|
Oct 05
|
Nov 05
|
Dec 05
|
Jan 06
|
Feb 06
|
Mar 06
|
Apr 06
|
May 06
|
Jun 06
|
Jul 06
|
Aug 06
|
Sep 06
|
Oct 06
|
Project Area excluding
Causeway Bay T/S
|
45.9
|
31.1
|
30.5
|
26.1
|
23.6
|
26.6
|
25.9
|
23.9
|
25.3
|
24.4
|
25.0
|
26.9
|
32.0
|
31.8
|
24.3
|
24.2
|
Causeway Bay T/S
|
27.4
|
21.8
|
14.8
|
19.0
|
12.8
|
15.5
|
12.3
|
11.0
|
14.8
|
12.3
|
11.4
|
15.8
|
18.5
|
15.6
|
17.4
|
14.6
|
TOTAL
|
73.3
|
52.9
|
45.3
|
45.1
|
36.4
|
42.1
|
38.2
|
34.9
|
40.1
|
36.7
|
36.4
|
42.7
|
50.5
|
47.4
|
41.7
|
38.8
|
Notes:
1.
Project
Area: Starts from the shoreline immediately to the west of the HKCEC and
extends in an easterly direction along the shoreline to the North Point
waterfront.
2.
The
above quantity represents the floating refuse collection by MD’s contractor Kai
Fat Harbour Cleaning Services Ltd.
3.
The
above quantity is on a monthly basis and in units of tonnes.
4.
T/S =
Typhoon Shelter
Dredged Marine Sediments
6.7.1
The
basic requirements and procedures for dredged mud disposal are specified under
the ETWB TCW No. 34/2002. The MFC
is responsible for the provision and management of disposal capacity for
dredged/excavated sediment, and DEP is responsible for the issue of permits for
marine disposal under the provisions of the Dumping at Sea Ordinance (Cap.
466).
6.7.2
The
dredged marine sediments would be loaded onto barges, transported to and
disposed of at the designated disposal sites at South of Cheung Chau, East of
Ninepin, East of Tung Lung Chau, South of Tsing Yi and East of Sha Chau to be
allocated by the MFC depending on their level of contamination or at other
disposal sites after consultation with the MFC and EPD. Based on the chemical screening results,
the majority of the marine sediment to be dredged was classified as contaminated
and would require Type 2 confined marine disposal. In accordance with the ETWB TCW No. 34/2002, the contaminated material must be dredged and transported with
great care, and the mitigation measures recommended in Section 5 of this Report
should be strictly followed.
Furthermore, the dredged contaminated sediment must be effectively
isolated from the environment upon final disposal and the project proponent
will consult the MFC about the disposal requirement.
6.7.3
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, at least 3 months prior to the
dredging contract being tendered.
6.7.4
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:
·
Bottom opening of barges
shall be fitted with tight fitting seals to prevent leakage of material.
·
Monitoring of the barge
loading shall be conducted to ensure that loss of material does not take place
during transportation. Transport
barges or vessels shall be equipped with automatic self-monitoring devices as
specified by the DEP.
·
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.
Good Site Practices
6.7.5
Adverse
impacts related to waste management are not expected to arise, provided that
good site practices are strictly followed.
Recommendations for good site practices during the construction
activities include:
·
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.
·
Training of site personnel
in proper waste management and chemical waste handling procedures.
·
Provision of sufficient
waste disposal points and regular collection for disposal.
·
Appropriate measures to
minimise windblown litter and dust during transportation of waste by either
covering trucks or by transporting wastes in enclosed containers.
·
Regular cleaning and
maintenance programme for drainage systems, sumps and oil interceptors.
·
A recording system for the
amount of wastes generated, recycled and disposed of (including the disposal
sites).
Waste Reduction Measures
6.7.6
Good
management and control can 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:
·
Sort C&D waste from
demolition of the existing structures to recover recyclable portions such as
metals.
·
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.
·
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.
·
Any unused chemicals or those
with remaining functional capacity shall be recycled.
·
Use of reusable non-timber
formwork to reduce the amount of C&D material.
·
Proper storage and site
practices to minimise the potential for damage or contamination of construction
materials.
·
Plan and stock construction
materials carefully to minimise amount of waste generated and avoid unnecessary
generation of waste.
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.
General Refuse
6.7.8
General
refuse should be stored in enclosed bins or compaction units separate from
C&D material. A licensed waste
collector should be employed by the contractor to remove general refuse from
the site, separately from C&D material. Preferably an enclosed and covered area
should be provided to reduce the occurrence of 'wind blown' light material.
Chemical Wastes
6.7.9
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.
Construction and Demolition Material
6.7.10
The
C&D material should be sorted on-site into inert C&D material (that is,
public fill) and C&D waste.
Nevertheless, since the removal of the temporary breakwater can only be
demolished at the very late stage of the Project when all of the reclamation
works have been completed, the C&D material generated from these demolition
activities could not be reused on site.
C&D waste, such as wood, glass, plastic, steel and other metals
should be reused or recycled and, as a last resort, disposed of to
landfill. It is recommended that a
suitable area be designated to facilitate the sorting process and a temporary
stockpiling area will be required for the separated materials.
6.7.11
In
order to monitor the disposal of public fill and C&D waste at public
filling facilities and to control fly tipping, a trip-ticket system 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.
6.7.12
Table 6.6 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 6.6 Summary
of 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
|
C&D Material
|
Removal of Temporary typhoon shelter
|
0.156Mm3
|
0.156Mm3
|
Sort on-site into :
·
Inert C&D material
·
C&D waste
|
To be disposed to public fill
reception facilities for other beneficial uses (approx 0.156Mm3)
|
Dredged
Sediments
|
Category H and Category M sediment
|
0.07
Mm3
|
0.07
Mm3
|
Techniques to minimise resuspension (closed grabs,
tight seal on barges, controlled loading and transfer)
|
Type 2 confined marine disposal - contaminated mud
pit
(approx. 0.07 Mm3)
|
Category L sediment
|
0.048
Mm3
|
0.048
Mm3
|
Type 1 open sea disposal - gazetted marine disposal
ground
(approx. 0.048 Mm3)
|
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 on-site or by licensed companies
Stored on-site within suitably designed containers
|
Chemical Waste Treatment Facility or other licensed
facility
|
General
Refuse
|
Waste paper, discarded
containers, etc. generated from workforce
|
approx. 26 kg per day
(preliminary estimate based on workforce of 40)
|
approx. 26 kg per day
|
Provide on-site refuse
collection points
|
Refuse station for compaction and containerisation
and then to landfill
|
6.8.1
With
the implementation of the recommended mitigation measures for the handling,
transportation and disposal of the identified waste arisings, no adverse
residual impact is expected to arise during the construction of the proposed
Project.
6.9.1
Waste
management will be the contractor’s responsibility to ensure that all wastes
produced during the construction of the Project are handled, stored and
disposed of in accordance with good waste management practices and EPD’s
regulations and requirements. The
mitigation measures recommended in Section 6.7 should form the basis of the
site Waste Management Plan to be developed by the Contractor in the
construction stage.
6.10.1 A review of the sediment quality data
from the marine ground investigation indicated that the majority of marine
sediments to be dredged at the proposed breakwater of the temporary typhoon
shelter were classified as contaminated.
The total dredged volume was estimated as approximately 0.118 Mm3, of which 0.07 Mm3 was classified as contaminated
(Category M and H) requiring Type 2 confined marine disposal, and 0.048 Mm3 was classified as Category L and would be
suitable for Type 1 open sea disposal.
With the implementation of the recommended mitigation measures in
accordance with the requirements of ETWB TCW No. 34/2002, no adverse residual
impact was predicted. Since the dredging activities are marine based activities
and negligible dust impacts on nearby air sensitive receivers would be expected.
The findings of the noise impact assessment in Section 4 of this report
indicated that adverse noise impact would not be expected during the course of
the dredging activities.
6.10.2
Wastes
generated by the construction activities will include C&D material, general
refuse from the workforce and chemical waste from the maintenance of
construction plant and equipment. Surplus material would require disposal
to designed public filling facilities (approximately 0.156Mm3). Provided that these identified waste arisings
are handled, transported and disposed of using approved methods and that
recommended good site practice are strictly followed, adverse environmental
impacts of air and odour emissions, noise, potential hazards, wastewater
discharge and transport would not be expected during the construction phase.
6.10.3
Floating
refuse is an existing waste and the Project itself is not designed to generate
floating refuse. Owing to the project area in close proximity to or within Victoria Harbour, limited amount of refuse and
debris may be unintentionally brought from the site into the harbour during
heavy rains or typhoons. Given that the Project would not worsen the shoreline
configuration and the implementation of appropriate control measures during
construction phase, it is considered that the future quantity of refuse to be
found along the shoreline would be similar if not better than the existing
situation. With the implementation
of the refuse collection system properly within the project area, no
insurmountable environmental impact with regard to floating refuse would be
anticipated during the construction phase.