Table of Contents
8.2 Legislation
Requirements and Evaluation Criteria
8.3 Expected Waste Arisings during
the Construction Phase
8.4 Expected Waste Arisings during
the Operation Phase
8.6 Residual
Environmental Impacts
8.7 Environmental
Monitoring and Audit
This
Section identifies the potential
waste arisings from the construction and operation of
the Project and the potential environmental impacts associated with the
storage, handling, transportation and disposal of the wastes. The assessment was undertaken in accordance
with the criteria set out in Annexes 7 and
15 of the EIAO-TM.
The
following legislation covers the handling, treatment and disposal of wastes in
·
Waste
Disposal Ordinance (WDO) (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 (DASO) (Cap. 466).
The
WDO prohibits the unauthorised
disposal of wastes, with waste defined as any substance or article which is
abandoned. Under the WDO, wastes can only be disposed of at
licensed waste disposal site. A breach
of these regulations can lead to the imposition of a fine and/or a prison
sentence. The WDO also provides for the issuing of licences
for the collection and transport of wastes.
Licences for the collection and transport of
construction waste or trade waste, however, are not issued currently.
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, but
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 came into operation on 1 December 2005. Processing of account applications by the EPD
started on the same day. A contractor
who undertakes construction work with value of HK$1 million or above is
required to open a billing account solely for the contract. Charging for the disposal of construction
waste started on 20 January 2006.
Depending
on the percentage of inert materials in the material, construction waste can be
disposed of at public fill reception facilities, landfills and outlying islands
transfer facilities, where differing disposal costs would be applied. This scheme encourages waste reduction and
hence minimise the costs of the Contractor or Project
Proponent. Table 8.1 summarises the Government waste disposal facilities for
construction waste and various charge levels.
Table 8.1 Government
Waste Disposal Facilities for Construction Waste
|
Government Waste
Disposal Facilities |
Type of
Construction Waste Accepted |
Charge per Tonne # |
|
Public fill reception facilities |
Consisting entirely of inert construction waste ++ |
HK$27 |
|
Sorting facilities |
Containing more than 50% by weight of inert
construction waste ++ |
HK$100 |
|
Landfills @ |
Containing not more than 50% by weight of inert
construction waste ++ |
HK$125 |
|
Outlying Islands Transfer Facilities @ |
Containing any percentage of inert construction
waste ++ |
HK$125 |
Notes:
# Except for
the Outlying Islands Transfer Facilities, the minimum charge load is 1 tonne, i.e. if a load of waste weighs 1 tonne
or less, it will be charged as 1 tonne. A load of
waste weighing more than 1 tonne will be charged at
0.1 tonne increment. For Outlying Islands Transfer
Facilities, the charge is $12.5 per 0.1 tonne and the
minimum charge load is 0.1 tonne.
++ Inert
construction waste means rock, rubble, boulder, earth, soil, sand, concrete,
asphalt, brick, tile, masonry or used bentonite.
@ If a load
of waste contains construction waste and other waste, that load will be
regarded as consisting entirely of construction waste for the purpose of
calculating the applicable charge.
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 such a 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.
Chemical waste producers shall register with
the EPD. Any person who contravenes this
requirement commits an offence and is liable to a fine and imprisonment. Producers of chemical wastes must treat their
wastes, utilising on-site plants licensed by the EPD
or have a licensed collector take the wastes to a licensed facility. For each consignment of wastes, the waste
producer, collector and disposer of the wastes must sign all relevant parts of
a computerised trip ticket. The system is designed to allow the transfer
of wastes to be traced from cradle-to-grave.
The
Regulation prescribes the storage
facilities to be provided on site including labelling and warning signs. To minimise the
risks of pollution and danger to human health or life, the waste producer is
required to prepare and make available written procedures to be observed in the
case of emergencies due to spillage, leakage or accidents arising from the storage
of chemical wastes. He/she must also
provide employees with training in such procedures.
The inert portion of construction waste ([1])
(also called public fill) may be taken to public fill reception
facilities. Public fill reception
facilities are operated by the Civil Engineering and Development Department
(CEDD). 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 the CEDD under delegated authority from the Director of Lands.
Under the licence
conditions, public fill reception facilities will only accept inert earth,
soil, sand, rock, boulder, rubble, brick, tile, concrete, asphalt, masonry or
used bentonite. In addition, in
accordance with paragraph 11 of Development
Bureau (DevB) Technical Circular (Works) (DevB TC(W)) No. 6/2010), the Public Fill Committee will
advise on the acceptance criteria (eg no mixing of
construction waste, nominal size of the materials less than 250mm, etc). The material
should, 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.
This
Regulation provides further control on
the illegal dumping of wastes on unauthorised
(unlicensed) sites. The illegal dumping
of wastes can lead to a fine and/or imprisonment.
Under
the DASO, a permit from the Director of Environmental Protection is required if
anyone intends to dispose and dump from vessels in the sea. The permit is valid for specific periods of
time and stipulates the (1) type and quantity of substances to be dumped; (2)
location of the disposal grounds; (3) requirement of equipment for monitoring
the disposal operations; and (4) environmental monitoring requirements.
Other
relevant guidance documents, which detail how the Project Proponent or
Contractor should comply with the local regulations, are as follows:
·
Waste Disposal Plan for Hong Kong (December 1989), Planning, Environment and
Lands Branch Government Secretariat, Hong Kong SAR Government;
·
Code of Practice on the Packaging, Labelling
and Storage of Chemical Wastes
(1992), EPD, Hong Kong SAR Government;
·
Hong Kong Planning Standards and Guidelines
Planning (2014), Planning Department, Hong Kong SAR
Government;
·
WBTC No. 2/93 - Public Dumps, Works Branch, Hong Kong SAR Government;
·
WBTC No. 2/93B - Public Filling Facilities, Works Branch, Hong Kong SAR Government;
·
WBTC No. 16/96 - Wet Soil in Public Dumps,
Works Branch, Hong Kong SAR Government;
·
Waste Reduction Framework Plan, 1998 to 2007, Planning, Environment and Lands Bureau,
Government Secretariat, 5 November 1998;
·
WBTC No. 4/98 and 4/98A - Use of Public Fill
in Reclamation and Earth Filling Projects, Works Bureau, Hong Kong SAR Government;
·
WBTC No. 25/99, 25/99A and 25/99C -
Incorporation of Information on Construction and Demolition Material Management
in Public Works Subcommittee Papers, Works Bureau, Hong Kong SAR Government;
·
WBTC No. 12/2000 - Fill Management, Works Bureau, Hong Kong SAR Government;
·
WBTC No. 19/2001 - Metallic Site Hoardings
and Signboards; Works
Bureau, Hong Kong SAR Government;
·
WBTC No. 11/2002 - Control of Site Crushers, Works Bureau, Hong Kong SAR Government;
· WBTC No. 12/2002 - Specifications
Facilitating the Use of Recycled Aggregates, Works
Bureau, Hong Kong SAR Government;
·
ETWB TC(W) No. 33/2002 - Management of
Construction and Demolition Material Including Rock, Environment,
Transport and Works Bureau, Hong Kong SAR Government;
·
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 Sites, Environment, Transport and Works Bureau,
Hong Kong SAR Government;
·
DevB TC(W) No. 6/2010 - Trip Ticket System for
Disposal of Construction & Demolition Materials, Development Bureau, Hong Kong SAR
Government; and
·
Practice Note for Authorized Persons and
Registered Structural Engineers No. 252 - Management Framework for Disposal of
Dredged/Excavated Sediment, Buildings
Department, Hong Kong SAR Government.
During the construction phase, the main
activities on land, which include site clearance, civil and building
construction works, and marine dredging, will potentially result in the
generation of waste. The typical waste types
associated with these activities include:
·
Waste from site clearance;
·
Excavated
materials (soil, rock and marine sediments) from the construction of seawater
intake and outfall, foundation/ basement of desalination plant and water mains
of the trunk feed system ([2]);
·
Dredged marine sediments from the construction of
seawater intake and outfall and desalination plant;
·
Construction and demolition (C&D) materials from
construction of new buildings and civil structures;
·
Chemical waste from maintenance of construction plant and
equipment; and
·
General refuse from construction workforce.
The natural
slope overlooking the northeast boundary of the new desalination plant at TKO
Area 137 has a history of minor landslides and contains some potentially
unstable boulders. Landslide and boulder
hazard mitigation works including mainly passive debris barriers and boulder
traps along the toe of the natural slope, some soil nailing at local steep
spots on the slope, stabilization of individual boulders by buttressing and
dowelling may be required to protect the new desalination plant for the
landslide and boulder hazards from this slope.
Slope mitigation works which involve minor excavation will be conducted
and therefore considered to be insignificant.
The CEDD is currently operating a temporary
fill bank at TKO Area 137, which is stockpiled or filled with inert C&D
materials with access roads between various parts of the site. The site will be occupied by the temporary
fill bank until end of 2018. CEDD has
agreed to hand over the 10 ha site cleared of stockpile for this Project by
late 2015. Thus the quantity of site
clearance waste (eg vegetation) is expected to be
small. This will be transferred to the
SENT Landfill or North East New Territories (NENT) Landfill for disposal.
With reference to the preliminary
construction programme, it is estimated that the quantities of excavated
materials to be generated from the construction of the seawater intake and
outfall, desalination plant and the mains laying are approximately
785 m3, 402 m3, 183,720 m3 and 42,733 m3,
respectively. The construction of
desalination plant shall involve slope mitigation works, which will also
generate about 56 m3 of excavated materials. With
reference to “ETWB TC(W)
No. 33/2002 Management of Construction and Demolition Material Including Rock”,
a C&D Material Management Plan (C&DMMP) has to be submitted with the
EIA Report to the Public Fill Committee (PFC) for approval in the event that
the Project generates more than 50,000 m3 of C&D material. The
C&DMMP for the Project has been included in Annex 8A of this EIA Report
and it will be submitted to PFC for approval.
It is assumed that half of the excavation
works will be completed in 2017 and 2018, respectively, and all the excavation
works will be completed by 2018. With reference to the C&DMMP and “Geological Profile along the proposed
alignment of Intake in Site Investigation Report (8901/B&V/0034)”, Table 8.2a below
presents the estimation of excavated materials to be generated and fill
materials to be required during the construction of the seawater intake and
outfall, desalination plant and mains laying.
Table 8.2a Cut and Fill Requirements of the Seawater
Intake & Outfall, Desalination Plant and Mains Laying
|
Locations |
Excavated
Materials Generated from Construction Works |
Filled
Materials Reused on Site (m3) |
Surplus
Excavated Materials (which are Inert C&D Material) Disposed of at Fill Bank
as Public Fill (m3) |
Surplus
Excavated Materials (which are Non-inert C&D Material) Disposed of at
Landfill as Construction Waste (m3) |
Surplus
Excavated Materials Disposed of as Marine Sediments (m3)
(d) |
|
Seawater Intake |
785 |
550 |
79 (a) |
0 |
157 (b) |
|
Seawater Outfall |
402 |
402 |
0 |
0 |
0 |
|
Desalination Plant (including slope mitigation
works) |
183,776 (c) |
0 |
180,173 |
2,744 |
859 |
|
Mains Laying |
42,733 |
25,961 |
16,404 |
368 |
- |
|
Total |
227,696 |
26,913 |
196,656 |
3,112 |
1,016 |
|
Notes (a) Assuming 10% of the total excavated materials
generated from the construction of seawater intake are Grade IV and V low
quality rock unsuitable for on-site filling.
The Surplus Excavated Materials Disposed of at Fill Bank as Public Fill
= 785 m3 X 10% = 79 m3. (b) Assuming 20% of the total excavated materials
generated from the construction of seawater intake are marine sediments. The Surplus Excavated Materials Disposed of
as Marine Sediments = 785 m3 X 20% = 157 m3. (c) 145,751 m3 of the total
excavated materials are generated from the construction of foundation/
basement of the desalination plant whilst 37,110 m3 of the total
excavated materials are generated from pilling works. The remaining 859 m3 of the
total excavated materials are marine sediments generated during the
excavation. The Excavated Materials
Generated from Construction Works = 145,751 m3 + 37,110 m3
+ 859 m3 = 183,720 m3.
The excavated material generated from the slope mitigation works is
also included into this section and is about 56 m3. Therefore the total excavated material is
183,720 m3 + 56 m3 = 183,776 m3 (d) Marine sediment
generated from land-based construction works. |
|||||
The excavated materials generated
from the construction works will be temporarily stockpiled on-site for
subsequent reuse at other parts of the Site.
About 12% of the excavated materials will be reused on-site as fill
materials for general filling. Table
8.2b below summarises the
estimated quantities of various kinds of excavated materials (excluding marine
sediments) generated during the construction works.
Table 8.2b Estimated
Quantities of Excavated Materials (Excluding Marine Sediments) Generated during
Construction Works
|
Material |
Quantity of Each Type
of Materials (m3) |
Quantity of Filled
Materials Reused on Site (m3) |
Quantity of Each
Type of Materials to be Disposed of
at Fill Bank as Public Fill (m3) |
Quantity of Each
Type of Materials to be Disposed of
at Landfill as Construction Waste (m3) |
|
Inert C&D Material (soft public fill) |
211,232 |
26,912 |
184,320 |
0 |
|
Grade I/II Granitic Rock |
9,146 |
0 |
9,146 |
0 |
|
Rock other than Grade I/II Granite |
3,190 |
0 |
3,190 |
0 |
|
Broken Concrete |
0 |
0 |
0 |
0 |
|
Non-inert Construction Waste |
3,112 |
0 |
0 |
3,112 |
|
Total
Volume (m3) |
226,680 |
26,912 |
196,656 |
3,112 |
|
Total
Weight (tonnage)* |
459,528 |
53,824 |
399,480 |
6,224 |
|
Note * - Converted by figures
from WSD Vetting Committee on C&DMM’s
memo (Ref. (3) In WSD 1421/58/02 Pt. 17 TJ (1) dated 9 December
2010. In-situ densities of rock and
soil to be 2.5 tonnes/m3 and 2.0 tonnes/m3 respectively |
||||
The excavation materials from surplus Inert C&D Material, Grade
I/II Granitic Rock and Rock other than Grade I/II Granite (about 196,656 m3 in volume or 399,480 tonnes in weight) will be disposed of at the TKO Area 137
Fill Bank (if it is still in operation) or other public fill reception
facilities. The average number of truck
trips associated with off-site disposal of surplus excavated materials at the
TKO Area 137 Fill Bank will be about 66 trucks per day ([3]). The TKO Area 137 Fill Bank is adjacent to the
site and thus no impact on the traffic in the vicinity of the site is
expected. The remaining excavated
materials which are construction waste (about 3,112 m3 in volume or
6,224 tonnes in weight) will be disposed of as
construction waste at SENT Landfill or its extension (if implemented) or NENT
Landfill. The number of truck trips for
off-site disposal of construction waste is about 1 truck trip per day, and no
adverse impact to the operation of these facilities is expected.
To
minimise the generation of excavated marine sediments,
various construction approaches and reuse options have been considered and
discussed, including trenchless method for submarine pipeline installation (see
Section 2). The present proposed work scheme represents a
concerted effort to reduce and manage dredged material generation. With the current optimal design, the
quantities of dredged marine sediments to be generated from dredging during the
construction of seawater intake and outfall are approximately 1,740 m3
and 4,590 m3, respectively.
Taking account of the excavated marine sediments generated during the
construction of seawater intake and piling of the desalination plant as
mentioned in Table 8.2a, the total quantity of marine sediments generated
will be approximately 7,346 m3 with a maximum of dredging rate at
3,500 m3 per day.
A
review of available baseline information on sediment quality was conducted and
a summary is provided below.
The closest EPD sediment monitoring station
in the vicinity of the proposed dredging location is station ES1 in the Eastern
Buffer Water Control Zone. The results
of seabed sediment testing conducted between 2010 and 2013 are presented in Table
8.2c. Based on EPD’s sediment
quality data collected at ES1, the levels of all contaminants are well below
the Lower Chemical Exceedance Level (LCEL).
Thus, the sediment in the vicinity of the submarine intake and outfall
are anticipated to be Category L sediment as defined under ETWB TC(W) No. 34/2002 Management Framework for Disposal of
Dredged/Excavated Sediment.
Table
8.2c EPD Sediment Monitoring data between
2010 and 2013 at ES1 of Eastern Buffer Water Control Zone
|
Contaminants |
Mean
Concentration in 2010 - 2013 |
LCEL
(1) |
UCEL
(2) |
|
Metals (mg/kg dry weight) |
|||
|
Cadmium
(Cd) |
<
0.1 |
1.5 |
4 |
|
Chromium
(Cr) |
23.6 |
80 |
160 |
|
Copper
(Cu) |
27.5 |
65 |
110 |
|
Mercury
(Hg) |
0.1 |
0.5 |
1 |
|
Nickel
(Ni) |
14.4 |
40 |
40 |
|
Lead
(Pb) |
28.3 |
75 |
110 |
|
Silver
(Ag) |
0.8 |
1 |
2 |
|
Zinc
(Zn) |
69.9 |
200 |
270 |
|
Metalloid (mg/kg dry
weight) |
|||
|
Arsenic
(As) |
5.7 |
12 |
42 |
|
Organic PAHs (3)
(ug/kg dry weight) |
|||
|
Low
MW PAHs |
28.9 |
550 |
3160 |
|
High
MW PAHs |
24.4 |
1700 |
9600 |
|
Organic-non-PAHs (ug/kg dry weight) |
|||
|
Total
PCBs (4) |
18.0 |
23 |
180 |
|
Notes: |
|
|
|
|
(1) Low Chemical Exceedance
Level |
|||
|
(2) High Chemical Exceedance
Level |
|||
|
(3) Polycyclic aromatic
hydrocarbons |
|||
|
(4) Polychlorinated biphenyls |
|||
Table
8.2d Results of testing of sediment samples
collected in 2013 during ground investigation of the submarine facilities of
the proposed desalination plant
|
Contaminants |
Station |
LCEL (1) |
UCEL (2) |
||||||||
|
GS1 (5) |
GS2(5) |
GS3 |
GS4 |
D1/SD1 |
D2/SD2 (5) |
D3/SD3 |
D4/SD4 (6) |
||||
|
Sampling Depth |
Seabed level |
Seabed level, 0.9m,
1.9m, 2.9m, and thereafter every 3m to the bottom of the marine deposit |
- |
- |
|||||||
|
Metals (mg/kg dry weight) |
|||||||||||
|
Cadmium (Cd) |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
1.5 |
4 |
|
|
Chromium (Cr) |
32 |
23 |
26 |
25 |
13 |
32 - 49 |
28 |
11 - 24 |
80 |
160 |
|
|
Copper (Cu) |
24 |
17 |
18 |
18 |
13 |
7 - 30 |
18 |
3 - 8 |
65 |
110 |
|
|
Mercury (Hg) |
0.1 |
0.08 |
0.06 |
0.07 |
0.12 |
<0.05 - 0.19 |
0.11 |
< 0.05 |
0.5 |
1 |
|
|
Nickel (Ni) |
17 |
12 |
14 |
13 |
4 |
22 - 33 |
14 |
5 - 15 |
40 |
40 |
|
|
Lead (Pb) |
35 |
28 |
25 |
22 |
37 |
15 - 38 |
24 |
7 - 19 |
75 |
110 |
|
|
Silver (Ag) |
0.4 |
0.2 |
0.2 |
0.3 |
0.2 |
<0.1 - 0.6 |
0.2 |
<0.1 |
1 |
2 |
|
|
Zinc (Zn) |
102 |
79 |
74 |
68 |
81 |
69 - 113 |
65 |
21 - 54 |
200 |
270 |
|
|
Metalloid (mg/kg dry weight) |
|||||||||||
|
Arsenic (As) |
8 |
5 |
4 |
3 |
7 |
3 - 14 |
5 |
<1 - 3 |
12 |
42 |
|
|
Organic PAHs (3) (ug/kg dry
weight) |
|||||||||||
|
Low MW PAHs |
<550 |
<550 |
<550 |
<550 |
<550 |
<550 |
<550 |
<550 |
550 |
3160 |
|
|
High MW PAHs |
<1,700 |
<1,700 |
<1,700 |
<1,700 |
<1,700 |
<1,700 |
<1,700 |
<1,700 |
1700 |
9600 |
|
|
Organic-non-PAHs (ug/kg dry weight) |
|||||||||||
|
Total PCBs (4) |
<18 |
<18 |
<18 |
<18 |
<18 |
<18 |
<18 |
<18 |
23 |
180 |
|
|
Organometallics (ug/ TBTL in
interstitial water) |
|||||||||||
|
Tributyltin (TBT) |
<0.015 |
<0.015 |
<0.015 |
<0.015 |
<0.015 |
<0.015 |
<0.015 |
<0.015 |
0.15 |
0.15 |
|
|
Notes: |
|||||||||||
|
(1)
Low Chemical Exceedance Level |
|||||||||||
|
(2)
High Chemical Exceedance Level |
|||||||||||
|
(3)
Polycyclic aromatic hydrocarbons |
|||||||||||
|
(4) Polychlorinated
biphenyls (5) In the close proximity of the dredging
extent but outside the direct footprint of the submarine intake structure |
|||||||||||
|
(6) Within the dredging extent of the
submarine outfall structure |
|||||||||||
Overall, the
collected sediment samples in the vicinity of proposed submarine intake and
outfall reported contaminant levels not exceeding the LCEL (Category L), except
for the sediment collected from SD2 at a depth of 10.90 – 11.90 m below seabed
which is determined as Category M due to the level of Arsenic exceeded the LCEL
but below the UCEL. It should be noted
that the dredging depth for the proposed submarine intake and outfall is about
4-6m below seabed and SD2 is not located within the direct footprint of the
proposed submarine intake. As such,
marine dredged sediments arising from the Project are likely to be Category
L.
For the
excavated marine sediments arising from piling of the desalination plant (Table 8.2a refers), desktop data from
the Engineering Feasibility Study of Development of Tseung
Kwan O Area 137 ([5])
reported that the sediments within Junk Bay were contaminated due to historical
industrial practices and the influence of contaminants from Victoria Harbour. Among the
measured parameters in the sediment collected beneath Area 137, only the level
of lead in middle and bottom layers of the sediments exceeded the LCEL but below
the UCEL (Table 8.2e). Thus the
excavated marine sediment arising from piling of desalination plant at Area 137
is expected to be Category M.
Table 8.2e Sediment sampling and testing data of Tseung Kwan O Area 137 Prior to Reclamation
|
Contaminants |
Concentration range |
LCEL (1) |
UCEL (2) |
||
|
Sampling Depth |
Top |
Middle |
Bottom |
- |
- |
|
Metals (mg/kg dry weight) |
|||||
|
Cadmium (Cd) |
< 0.06 - <0.13 |
< 0.06 - < 0.17 |
< 0.06 - <0.15 |
1.5 |
4 |
|
Chromium (Cr) |
17 - 29 |
24 - 30 |
31 - 45 |
80 |
160 |
|
Copper (Cu) |
4.4 - 14 |
4.3 - 10 |
8.1 - 19 |
65 |
110 |
|
Mercury (Hg) |
0.01 - 0.11 |
0.01 - < 0.04 |
0.03 |
0.5 |
1 |
|
Nickel (Ni) |
11 - 21 |
15 - 26 |
25 - 30 |
40 |
40 |
|
Lead (Pb) |
17 - 57 |
18 -
78 |
28 -
78 |
75 |
110 |
|
Silver (Ag) |
n/a (5) |
n/a |
n/a |
1 |
2 |
|
Zinc (Zn) |
50 - 74 |
60 - 69 |
70 - 89 |
200 |
270 |
|
Notes: |
|
|
|
|
|
|
(1)
Low Chemical Exceedance Level |
|||||
|
(2)
High Chemical Exceedance Level |
|||||
|
(3) Polycyclic
aromatic hydrocarbons |
|||||
|
(4)
Polychlorinated biphenyls |
|||||
|
(5)
Not available |
|||||
Table
8.2f Proposed Disposal Options for Different
Types of Marine Dredged Sediments Arising from the Project
|
Sediment
Type |
In
sit Volume (m3) |
Bulk
Volume (m3) (1) |
Proposed
Disposal Option |
|
Category L |
6,330 |
8,229 |
Type I Open Sea Disposal to the areas
approved by MFC/ CEDD |
|
Category M (2) (Mpass
and/or Mfail) |
1,016 |
1,321 |
Type I Open Sea Disposal at dedicated
site if sediment samples passed the biological screening, or Type 2 Confined
Marine Disposal if sediment samples failed the biological screening, as
approved by MFC/ CEDD |
|
Total |
7,346 |
9,550 |
- |
|
Note: (1) Bulk volume with bulking
factor of 1.3 (2) In
case cement stabilization is not a practical treatment for the excavated
marine sediments, the sediments may be disposed according to ETWB TC(W) No. 34/2002. |
|||
No
demolition works will be required for the Project. C&D materials (consisting of concrete,
brick, wood, packing materials, plastics, metal and steel) will be generated
from the construction of the civil structures and buildings. The inert portion of the C&D materials is
referred to as public fill and the non-inert portion is referred to as
construction waste. Public fill will be
disposed of at TKO Area 137 Fill Bank (if it is still in operation), or other
public fill reception facilities. The
construction waste will be disposed of to the SENT Landfill or its extension (if implemented)
or NENT Landfill.
The gross floor area (GFA) of the buildings to be constructed are summarised in Table 8.3.
Table 8.3 Summary of GFA of Buildings to be
Constructed at the Site
|
Civil
Structures and Buildings |
Gross Floor
Area |
|
Desalination
Plant |
|
|
Incoming Switchgear Room |
400 |
|
132kV Substation |
972 |
|
Sludge Filter Press Building |
3,290 |
|
Sludge Thickener (I) |
741 |
|
Chlorine Storage (I) & (II) |
5,576 |
|
Underground Clear Water Storage Tank (I) |
500 |
|
Chlorine Contact Tank (I) |
850 |
|
Post Treatment (I) |
2,030 |
|
Chemical Building |
7,020 |
|
Maintenance Workshop |
442 |
|
Reverse Osmosis Building (I) + Secondary Stage Media
Filter (I) |
11,396 |
|
DAF (I) |
8,624 |
|
First Stage Media Filters (I) |
6,720 |
|
Administrative Building and Laboratory |
3,132 |
|
Intake Pumping Station |
3,036 |
|
Standby Generator & Switchgear Room |
154 |
|
Treated Water Pump Station + Switchroom
(III) |
1,586 |
|
Sodium Hypochlorite Storage Tanks and Dosing Station |
484 |
|
Total |
56,953 |
With the assumption of 0.1 m3 of
C&D materials generated per m2 of GFA constructed ([6]),
approximately 5,695 m3 of C&D materials will be generated from the
construction of civil structures and buildings at the project site. To reduce the volume of construction waste to
be disposed of at landfill, the C&D materials will be sorted into public
fill and construction waste on-site.
Assuming the ratio of inert waste to non-inert waste is 8:2 ([7]),
the volumes of public fill and construction waste are estimated to be 4,556 m3
and 1,139 m3, respectively.
In accordance with the preliminary construction programme, the duration
of the building works will be about 12 months.
Thus the estimated average public fill and construction waste to be
disposed off-site will be about 15.2 m3/day and 3.80 m3/day
([8]),
respectively. The public fill will be
disposed of at the TKO Area 137 Fill Bank (if it is still in operation), or
other public fill facilities, and construction waste will be disposal of at
SENT Landfill or its extension (if implemented) or NENT Landfill. Recyclable materials segregated from the
construction waste (eg paper, scrap metal, scrap
plastic, etc.) will be delivered to recyclers for recycling.
The numbers of truck trips associated with off-site disposal of public fill and construction waste will be about 2 and 1 truck trips per day, respectively. With respect to the anticipated small numbers of truck trip to be generated, the potential traffic impact will be negligible. It is not anticipated that the disposal of the small amount of public fill and construction waste to public filling facilities and landfill, respectively will have adverse impact to the operation of these facilities.
Chemical
waste, as defined under the Waste
Disposal (Chemical Waste) (General) Regulation, includes any unwanted
substances specified under Schedule 1 of
the Regulation. Substances likely to be generated from the
construction and modification works of the Project will include:
·
Used paint, 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 will 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.
It
is difficult to quantify the exact amount of chemical waste that will arise from
the construction activities since it will be highly dependent on the
contractor’s on-site maintenance activities and the quantity and/ or types of
plant and equipment utilised. With respect to the scale of the construction
activities, it is anticipated that the quantity of chemical waste to be
generated will be relatively small. The
chemical waste will be collected by licensed chemical waste collectors and
delivered to the licensed chemical waste treatment facilities for disposal (eg Chemical Waste Treatment Centre (CWTC) in Tsing Yi).
With
the incorporation of suitable arrangements for the storage, handling,
transportation and disposal of chemical wastes under the requirements stated in
the Waste Disposal (Chemical Waste)
(General) Regulation and the Code of
Practice on the Packaging, Labelling and Storage of Chemical Wastes, no
adverse environmental (including air and odour
emissions, noise and wastewater discharge) and health impacts, and hazards will
result from the handling, transportation and disposal of chemical waste arising
from the Project.
The presence of a construction site with
workers and associated site office will result in the generation of general
refuse (mainly consists of food waste, aluminium cans,
plastic bottles, waste paper and glass bottles) which requires off-site
disposal. The storage of general refuse
has the potential to give rise to adverse environmental impacts, if not
properly managed. These include odour if the waste is not collected frequently, windblown
litter and visual impact.
It
is conservatively estimated that a maximum of about 160 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
maximum amount of general refuse to be generated will be about 104 kg per
day.
To
reduce the quantity of general refuse to be disposed of at landfill, recyclable
materials (i.e. paper, plastic bottles, aluminium
cans and glass bottles) will be segregated on-site for off-site recycling, as
far as practicable. Adequate number of
enclosed waste containers and recycling bins will be provided to avoid
over-spillage of waste and/ or recyclable materials.
The
non-recyclable refuse will be placed in bags and stored in enclosed containers,
and disposed of on a daily basis to the West Kowloon Transfer Station/ Sha Tin
Transfer Station. Given that the
quantity of general refuse to be disposed of at landfill is small, no adverse
impact on the operation of the refuse transfer station is anticipated.
With
the implementation of the mitigation measures recommended in Section 8.5, no adverse environmental
impacts (including potential hazard, dust emissions, noise and wastewater
discharge) caused by storage, handling, transport and disposal of general refuse
are expected.
During the operation
of the desalination plant, the major waste types to be generated include:
·
Dewatered sludge from the pre-treatment system and filter
backwash;
·
Chemical waste from maintenance of the plant and
equipment; and
·
General Refuse from operators.
The
desalination plant is designed with an initial capacity of 50 million tpa, expandable to an ultimate capacity of 90 million tpa in the future.
With respect to the preliminary design, seawater will be drawn from the
seawater intake system to the pre-treatment system for pre-treatment by
clarification followed by filtration prior to the Seawater Reverse Osmosis
(SWRO) process. Coagulant/ polymer will
be added to feed water for coagulation and flocculation. The chemicals to be used in various treatment
processes are summarised in Table 8.4 below.
Table 8.4 Summary of Chemicals to be Used in
Various Treatment Processes
|
Chemicals |
Treatment Processes and Purpose |
|
Sodium Hypochlorite |
Pretreatment - Bio growth control |
|
Ferric Chloride or Alum |
Pretreatment - Coagulation |
|
Sulphuric Acid |
Pretreatment - pH Adjustment |
|
Polymer |
Pretreatment - Flocculation |
|
Sodium meta Bisulphite |
Pretreatment - Dechlorination |
|
Antiscalant |
RO membranes - Scaling control |
|
Sodium Hydroxide |
RO membranes - pH adjustment (if required) |
|
Carbon Dioxide |
Post Treatment - pH adjustment and remineralisation |
|
Hydrated Lime |
Post Treatment - pH adjustment and remineralisation |
|
Sodium Silicofluoride |
Post Treatment – Fluoridation for teeth protection |
|
Liquid Chlorine |
Post Treatment - Final disinfection |
|
Polymer |
Sludge Conditioning - Sludge Thickening/Dewatering |
The amount of grit/screenings to
be generated from the preliminary screening process before the seawater
entering the intake sump is considered to be negligible. The
sludge generated from clarification and filter backwash will be thickened and
dewatered to 30% dry solids content by weight.
The estimated generation rates of dewatered sludge from the plant are
approximately 27 tpd and 55 tpd
with the treatment capacity of 135 million liter per day (MLD) and 270 MLD,
respectively. The dewatered
sludge will be transported by trucks/ barges for disposal at the landfill.
The
maximum number of truck trips associated with off-site disposal of the
dewatered sludge will be about 6 truck trips per day. With respect to the anticipated small number
of truck trip to be generated, the potential traffic impact will be
negligible. It is not anticipated that
the disposal of the small amount of dewatered sludge to NENT or West New
Territories (WENT) Landfills will have adverse impact to the operation of the
landfill.
Limited chemical waste (mainly waste lube
oil, spent solvents, waste paint from maintenance of mechanical and electrical
equipment and waste chemicals containers for various treatment processes) will
arise from the operation activities of the plant. In addition, following chemical reactions
between the chemicals listed in Table 8.4
and the water or sludge, the chemicals will be converted to other physical and
chemical forms and will become part of the water and/ or sludge. It is anticipated that the quantity of
chemical waste to be generated during the operation phase will be small
depending on the maintenance schedule.
With the
incorporation of suitable arrangements for storage, handling, transportation and
disposal of chemical wastes in accordance with the requirements stated in the Waste Disposal (Chemical Waste) (General)
Regulation and the Code of Practice
on the Packaging, Labelling and Storage of Chemical Wastes, no adverse
environmental (including air and odour emissions, and
water quality) and health impacts, and hazards will result from the handling,
transportation and disposal of chemical waste arising from the operation of the
Project.
General
refuse will arise from the operators and visitors during the operation
phase. General refuse may consist of
food waste, plastic, glass bottles, aluminium cans
and waste paper. It is estimated up to
about 40 operators will be working on-site and 60 visitors will be visiting the
plant each day. With an estimated
general refuse disposal rate of 0.65 kg per capita per day, the amount of
general refuse to be disposed of by the operators will be about 65 kg per day
while the amount of general refuse generated by visitors is considered to be
negligible. With the provision of
recycling bins at the plant and promotion of the waste mininisation
and recycling initiatives, it is anticipated that the recycling rate will be
high and that the total general refuse to be disposed of is likely to be
lower. Source separation will be
conducted throughout the plant.
Recyclable materials (i.e. paper, plastic bottles, aluminium
cans and glass bottles) will be separated for recycling, in order to reduce the
amount of general refuse to be disposed of at landfill.
The
non-recyclable waste will be delivered to the West Kowloon Transfer Station/
Sha Tin Transfer Station on a daily basis.
With respect to the small quantity of general refuse to be disposed of
at the transfer station, no adverse impact on the operation of the transfer
station is anticipated. With the
implementation of the mitigation measures recommended in Section 8.5.2, no adverse environmental impacts (including
potential hazard, air and odour emissions, noise and
wastewater discharge) caused by the storage, handling, transport and disposal
of general refuse are expected.
The assessment indicates that with the
implementation of the proposed waste management practices at the work site, no
adverse environmental impacts are envisaged for the handling, collection and
disposal of waste arising during the construction phase of the Project.
This
Section further describes the good
construction site practices to avoid or further reduce the potential
environmental impacts associated with the handling, collection and disposal of
construction and chemical wastes arising from the construction.
The
contractor(s) must ensure that all the necessary waste disposal and marine
dumping permits or licences are obtained prior to the
commencement of the construction works.
The
contractor(s) will open a billing account with the EPD in accordance with the Waste Disposal (Charges for Disposal of
Construction Waste) Regulation.
Every construction waste or public fill load to be transferred to
Government waste disposal facilities (eg public fill
reception facilities, sorting facilities and landfills) will be provided with 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 also be established
in accordance with DevB TC(W) No. 6/2010 to monitor the
disposal of construction waste at landfill and to control fly-tipping. The trip-ticket system will be included as
one of the contractual requirements and implemented by the contractor(s).
A
waste management plan (WMP) as stated in the “ETWB TC(W) No. 19/2005, Environmental
Management on Construction Sites” for the amount of waste generated, recycled
and disposed of (including the disposal sites) will be established and
implemented during the construction phase as part of the Environmental
Management Plan (EMP). The Contractor
will be required to prepare the EMP and submit it to the Architect/ Engineer
under the Contract for approval prior to implementation.
The management of dredged/ excavated sediment
management requirement from ETWB TC(W)
No. 34/2002 will be incorporated in the Specification of the Contract
Documents.
Most
of the excavated materials are expected to be reused on site as fill materials
for general filling. A surplus of about
200,784 m3 of excavated materials will require off-site disposal, of
which 196,656 m3 of inert C&D materials will be disposed
off-site to the public fill reception facilities; 3,112 m3 of
non-inert C&D materials will be disposed of at SENT Landfill or its
extension (if implemented) or NENT Landfill; and the remaining 1,016 m3
of the excavated materials will be reused as fill materials on-site after
cement stabilization or will be disposed with the dredged marine sediments in
case cement stabilization is not a practical treatment. The C&DMMP for the Project has been
prepared in accordance with the ETWB
TC(W) No. 33/2002 and included in Annex
8A of this EIA Report. The
C&DMMP will facilitate the contractor(s) in the preparation of WMP and to
manage the surplus excavated materials and minimise
C&D materials during construction phase.
C&D
materials will be segregated on-site into public fill and construction waste
and stored in different containers or skips to facilitate reuse of the public
fill and proper disposal of the construction waste. Specific areas of the Site will be designated
for such segregation and storage if immediate use is not practicable. Prefabrication will be adopted as far as
practicable to reduce the construction waste arisings.
The
contractor(s) will register as a chemical waste producer with the EPD. Chemical waste will be handled in accordance
with the Code of Practice on the
Packaging, Handling and Storage of Chemical Wastes as listed below.
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 L 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.
General
refuse will be stored in enclosed bins separately from construction and
chemical wastes. The general refuse will
be delivered to the West Kowloon Transfer Station/ Sha Tin Transfer Station,
separately from construction and chemical wastes, on a daily basis to reduce odour, pest and litter impacts.
Recycling
bins will be provided at strategic locations within the Site to facilitate
recovery of recyclable materials (including aluminium
can, waste paper, glass bottles and plastic bottles) from the Site. Materials recovered will be sold for
recycling.
In
addition, to avoid any odour and litter impact,
accurate number of portable toilets will be provided for workers on-site.
At
the commencement of the construction works, training will be provided to
workers on the concepts of site cleanliness and on appropriate waste management
procedures, including waste reduction, reuse and recycling.
Thickened and dewatered sludge from the plant will
be transported to the landfill by
trucks. The requirement on the minimum
dry solid content (30%) in the dewatered sludge to be disposed of at landfills
as stipulated in the WDO will be incorporated in the Specification of the
Contract Documents.
The measures for management of chemical waste
during operation phase are similar to those outlined in Section 8.5.1.
Management
approach of general refuse arises from the on-site operators and visitors to
the plant during operation phase will be similar to that in construction
phase. General refuse and
non-recyclables will be stored in enclosed bins and transferred to the West
Kowloon Transfer Station/ Sha Tin Transfer Station on a daily basis for
avoidance of pest and ordour nuisance. Recycling bins for recyclable materials
(including aluminium can, waste paper, glass bottles and plastic
bottles) will be placed at the visitor/ admin/ lab building and transported
off-site for recycling on a regular basis.
No
residual waste management impact is envisaged during the construction and
operation phases of the Project.
It
is recommended that weekly audits of the waste management practices be carried
out during the construction phase to determine if wastes are being managed in
accordance with the recommended good site practices, WMP and C&DMMP. The audits will investigate all aspects of
waste management including waste generation, storage, handling, recycling,
transportation and disposal.
No
EM&A requirements will be required for the operation phase.
The
estimated waste arisings and recommend waste management
arrangements during the construction and operation phases of the Project are summarised in Table 8.5.
Table 8.5 Summary
of Estimated Waste Arisings and Recommended Waste
Management Arrangements
|
Types of Waste |
Quantity |
Treatment Options/
Disposal Locations |
|
Construction Phase |
|
|
|
Site Clearance Waste |
Small |
SENT Landfill or NENT Landfill |
|
Excavated Materials generated from the Construction of the
Seawater Intake and Outfall, Desalination Plant and Mains Laying (Except
excavated marine sediments) |
227,696 m3 (of
which 26,913 m3 is reused
onsite as filled materials, 196,656 m3 is inert C&D material
and 3,112 m3 is non-inert C&D material) |
Excavated materials will be
reused on-site as fill materials as far as practicable. 196,656 m3 of
surplus excavated materials (which
are inert C&D materials) will be disposed of at TKO
Area 137 Fill Bank (if it is still in operation) or other public fill
reception facilities; 3,112 m3
of the surplus excavated materials (which are non-inert C&D waste)
will be disposed of at SENT Landfill or its extension (if implemented) or
NENT Landfill; and 1,016 m3 of the surplus excavated materials
will be reused as fill materials on-site after cement stabilization or will
be disposed with the dredged marine sediments in case cement stabilization is not a practical
treatment. |
|
Marine Sediments |
7,346 m3 (in situ
volume): Intake: 1,740 m3 Outfall: 4,590 m3 |
To be disposed of at
specific area as
instructed by MFC/ CEDD under the ETWB
TC(W) No. 34/2002 for Category ‘L’ and Category ‘M’ sediments. The
project proponent will implement the project in accordance with the DASO and
the requirements as stipulated in ETWB
TC(W) No. 34/2002, prior to the application and allocation of space for
dredging and disposal of sediment arising from the project. |
|
Excavated marine sediments from piling of desalination plant: 1,016 m3 |
To be reused as fill material on-site after cement stabilization. In case cement stabilization is not a
practical treatment for the excavated marine sediments, the sediments may be
disposed according to ETWB TC(W) No.
34/2002. |
|
|
Inert C&D Material – public fill generated during the building
works |
4,556 m3 (Section 8.3.4 refers) |
Disposed of at TKO Area 137 Fill Bank (if
it is still in operation), or other pubic fill reception facilities. |
|
Non-inert C&D Material – C&D waste generated during the
building works |
1,139 m3 (Section 8.3.4
refers) |
SENT Landfill or its extension (if
implemented) or NENT Landfill |
|
Chemical Waste |
Small |
CWTC or other licensed chemical waste recycling or treatment
facilities |
|
General Refuse |
104 kg per day |
Recyclable materials: on-site sorting and off-site
recycling Non-recyclable refuse: West
Kowloon Transfer Station/ Sha Tin Transfer Station |
|
Operation Phase |
|
|
|
Dewatered
Sludge |
27 tpd (with plant treatment
capacity of 135 MLD) 55 tpd (with plant treatment
capacity of 270 MLD) |
WENT or NENT
Landfills |
|
Chemical
Waste |
Small |
CWTC or
other licensed chemical waste recycling or treatment facilities |
|
General
Refuse |
65 kg
per day |
Recyclable materials: on-site sorting and
off-site recycling. Non-recyclable
refuse: West Kowloon
Transfer Station/ Sha Tin Transfer Station |
It is estimated that a total of about 227,696
m3 of excavated materials will be generated from the construction of
the seawater intake and outfall, basement/ foundation and piling works of the
desalination plant and the mains laying works, of which 26,913 m3 of
the excavated materials will be reused on-site for general filling. A surplus of about 196,656 m3 of the excavated materials
(inert C&D) will be disposed off-site to the public fill reception
facilities; 3,112 m3 of the excavated materials (non-inert C&D)
will be disposed of at SENT Landfill or its extension (if implemented) or NENT
Landfill; and 1,016 m3 of the excavated materials will be reused
on-site as fill materials after cement stabilization far as practicable or will
be disposed as dredged marine sediments (ETWB
TC(W) No. 34/2002) in case cement stabilization is not a practical
treatment. With reference to ETWB TC(W) No. 33/2002, a C&DMMP for
the Project has been prepared and included in Annex 8A of this EIA Report.
With the inclusion of marine sediments generated from excavation (1,016
m3), it is estimated that a total of 7,346 m3 of marine
sediments will be generated from the construction of seawater intake and
outfall and desalination plant (including slope mitigation works). The marine sediments will be disposed of in
accordance with ETWB TC(W) No. 34/2002. The project proponent will implement the
project in accordance with the DASO and the requirements as stipulated in ETWB TC(W) No. 34/2002, prior to the
application and allocation of space for dredging and disposal of sediment
arising from the project.
During the construction of civil structures
and buildings within the Site, it is estimated that a total of about 4,556 m3
of public fill and 1,139 m3 of construction waste will be
generated. The public fill and the
construction waste will be disposed of at TKO Area 137 Fill Bank (if it is
still in operation), or other public fill reception facilities and landfill, respectively.
With respect to the scale of the construction
activities, it is anticipated that the quantity of chemical waste to be
generated will be small. It is also
estimated that about 104 kg of general refuse will be generated per day by the
construction workers. With the
implementation of general good construction site practices, the construction of
the Project will not cause adverse waste management, traffic or environmental
impacts (including potential hazard, air and odour
emissions, noise and water quality).
It
is estimated that about 27 tpd and 55 tpd of dewatered
sludge (with a minimum dry solid content of 30%) will be generated from the
desalination plant with the treatment capacity of 135 MLD and 270 MLD,
respectively. The dewatered sludge will
be transferred to landfill by trucks.
Similar to the construction phase, chemical
waste arises from operation activities of the plant is expected to be
small. It
is estimated that a total of approximately 65 kg of general refuse will be
generated from the operation of the plant on a daily basis. To facilitate waste avoidance and minimisation, recyclable materials will be sorted on-site
with the use of recycling bins. The
non-recyclable refuses will be delivered to West Kowloon Transfer Station/ Sha
Tin Transfer Station.
With
good site practices and proper operation and maintenance of the facilities, the
potential environmental impacts (including potential hazard, air and odour emissions, noise and water quality) associated with the
storage, handling, collection, transport and disposal of waste arising from the
operation of the Project will meet the criteria specified in the EIAO-TM and no adverse waste management
impacts are anticipated.
([1])
“Construction
waste” refers to materials arising from any land excavation or formation,
civil/building construction, road works, building renovation or demolition
activities. It includes various types of
reusable materials, building debris, rubble, earth, concrete, timber and mixed
site clearance materials. When sorted
properly, materials suitable for land reclamation and site formation (known as
public fill) should be reused at public fill reception facilities. The rock and concrete can be crushed and
processed to produce aggregates for various civil and building engineering
applications. The remaining construction
waste (comprising timber, paper, plastics, and general refuse) are to be
disposed of at landfills.
([2]) The “desalination plant” includes the pumping station and treated water storage tank of the trunk feed system; and the works related to the fresh water mains of the trunk feed system refers to “mains laying works” hereinafter.
([3]) Assuming 25 working days per month and
the total working days over the 12-month period is 300 days. 24-tonne trucks with payload of 10 tonnes are used.
([4]) Category L: Sediment with all
contaminant levels not exceeding the Lower Chemical Exceedance Level (LCEL).
The material must be dredged, transported and disposed of in a manner which
minimizes the loss of contaminants either into solution or by re-suspension.
([5]) APH Consultants (1993) Engineering
Feasibility Study of Development of Tseung Kwan O
Area 137. Territory Development
Department – South Easr New Territories Development
Office.
([6]) Cheung CM, Wong KW, Fan CN and Poon CS (1993),
Reduction of Construction Waste: Final Report, The Hong Kong Polytechnic
University and Hong Kong Construction Association.