4.1 This section
evaluates the potential water quality impacts that are likely to be generated
during the construction and operation phases of the proposed Project.
Appropriate mitigation measures were identified, where necessary, to mitigate
the potential water quality impacts to acceptable levels.
Environmental Impact Assessment Ordinance (EIAO),
Cap.499, S.16
4.2 The Technical Memorandum on Environmental
Impact Assessment Process (EIAO-TM) is issued by the EPD under Section 16
of the EIAO. It specifies the
assessment method and criteria that need to be followed in this Study. Reference sections in the EIAO-TM provide
the details of the assessment criteria and guidelines that are relevant to the
water quality impact assessment, including:
·
Annex 6 Criteria for Evaluating Water Pollution
·
Annex 14 Guidelines for Assessment of Water Pollution
Marine Water Quality Objectives
4.3 The Water Pollution Control Ordinance
(WPCO) Cap.358 provides Water Control Zones (WCZ). Corresponding statements of Water Quality Objectives (WQO) are
stipulated for different water regimes (marine waters, inland waters, bathing
beaches subzones, secondary contact recreation subzones and fish culture
subzones) in the WCZ based on their beneficial uses. A summary of WQOs for
Victoria Harbour WCZ is given in Table
5.1Table
5.1Table 5.1Table 5.1Table 5.1Table 5.154.1.
Table 5.1Table 45.1 Summary of Water Quality Objectives for
Victoria Harbour WCZ
|
Parameters
|
Objectives
|
Sub-Zone
|
|
Offensive Odour, Tints
|
Not to be present
|
Whole zone
|
|
Visible
foam, oil scum, litter
|
Not to
be present
|
Whole zone
|
|
Dissolved
Oxygen (DO) within 2 m of the seabed
|
Not less
than 2.0 mg/L for 90% of samples
|
Marine
waters
|
|
Depth-averaged
DO
|
Not less
than 4.0 mg/L for 90% of samples
|
Marine
waters
|
|
pH
|
To be in
the range of 6.5 - 8.5, change due to human activity not to exceed 0.2
|
Marine
waters
|
|
Salinity
|
Change
due to human activity not to exceed 10% of ambient
|
Whole
zone
|
|
Temperature
|
Change
due to human activity not to exceed 2 oC
|
Whole
zone
|
|
Suspended
solids (SS)
|
Not to
raise the ambient level by 30% caused by human activity
|
Marine
waters
|
|
Unionised
Ammonia (UIA)
|
Annual
mean not to exceed 0.021 mg/L as unionised form
|
Whole
zone
|
|
Nutrients
|
Shall
not cause excessive algal growth
|
Marine
waters
|
|
Total
Inorganic Nitrogen (TIN)
|
Annual
mean depth-averaged inorganic nitrogen not to exceed 0.4 mg/L
|
Marine
waters
|
|
Toxic
substances
|
Should
not attain such levels as to produce significant toxic, carcinogenic,
mutagenic or teratogenic effects in humans, fish or any other aquatic
organisms.
|
Whole
zone
|
|
Human
activity should not cause a risk to any beneficial use of the aquatic
environment.
|
Whole
zone
|
Source: Statement
of Water Quality Objectives (Victoria Harbour (Phases One, Two and Three) Water
Control Zone).
Hong Kong Planning Standards and Guidelines (HKPSG)
4.4 The HKPSG, Chapter 9 (Environment),
provides additional information on regulatory guidelines against water
pollution for sensitive uses such as aquaculture and fisheries zones, bathing
waters and other contact recreational waters.
Water Supplies Department Water Quality Objectives
4.5 Besides the WQO set under the WPCO, the
Water Supplies Department (WSD) has also specified a set of seawater quality
objectives for water quality at seawater intakes. The list is shown in Table 5.2Table 5.2Table 5.2Table 5.2Table 5.254.2. The relevant criteria for suspended solids
(SS) are the target limit of 10 mg/L.
Table 5.2Table 54.2 WSD Standards at Sea Water Intakes
|
Parameter (in mg/L unless otherwise stated)
|
WSD Target Limit
|
|
Colour (HU)
|
< 20
|
|
Turbidity (NTU)
|
< 10
|
|
Threshold Odour Number (odour unit)
|
< 100
|
|
Ammoniacal Nitrogen
|
< 1
|
|
Suspended Solids
|
< 10
|
|
Dissolved Oxygen
|
> 2
|
|
Biochemical Oxygen Demand
|
< 10
|
|
Synthetic Detergents
|
< 5
|
|
E. coli (no. / 100 ml)
|
<
20,000
|
Cooling Water Intake Standards
4.6 Based on the information provided by the
individual cooling water intake operators, no specific requirement on seawater
quality at the cooling water abstraction points was identified.
Technical Memorandum
4.7 Besides setting the WQOs, the WPCO
controls effluent discharges into any WCZ through a licensing system. The Technical Memorandum on Standards for Effluents Discharged
into Drainage and Sewerage Systems, Inland and Coastal Waters (TM-DSS), issued under
Section 21 of the WPCO, gives guidance on permissible effluent discharges based
on the type of receiving waters (foul sewers, storm water drains, inland and
coastal waters). The limits control the physical, chemical and microbial
quality of effluent. Any sewage from
the proposed construction activities should comply with the standards for
effluent discharged into the foul sewers, inshore waters or marine waters of
the Victoria Harbour WCZ, shown in Table 1, Table 9a and Table 9b,
respectively, of the TM-DSS.
Practice Note
4.8 A practice note for professional persons
has been issued by the EPD to provide guidelines for handling and disposal of
construction site discharges. The ProPECC PN 1/94 “Construction Site Drainage”
provides good practice guidelines for dealing with ten types of discharge from
a construction site. These include
surface runoff, groundwater, boring and drilling water, bentonite slurry, water
for testing and sterilisation of water retaining structures and water pipes,
wastewater from building construction, acid cleaning, etching and pickling
wastewater, and wastewater from site facilities. Practices given in the ProPECC PN 1/94 should be followed as far
as possible during construction to minimise the water quality impact due to
construction site drainage. For
operational stage effluent handling, treatment and disposal, reference should
be made to ProPECC PN 5/93.
Assessment Criterion for Coral Impact
4.9 According to Pastorok and Bilyard and Hawker and Connell , a sedimentation rate
higher than 0.1 kg/m2/day would introduce moderate to severe impact
upon corals. This criterion has been
adopted in recently approved EIA studies such as Eastern Waters MBA Study , West Po Toi MBA Study and Tai Po Gas Pipeline
Study [5].
4.10 The marine water quality monitoring data
routinely collected by EPD were used to establish the baseline condition. The EPD monitoring stations in Victoria
Harbour include VM1, VM2, VM4, VM5, VM6 and VM7 (Figure 54.1).
A summary of EPD monitoring data collected in 2002 and 2003 is presented
in Table
5.3Table
5.3Table 5.3Table 5.3Table 5.354.3 and Table 54.4 respectively for
VM5, VM6 and VM7 which are the closest monitoring stations to the Macau Ferry
Terminal (MFT). As the Harbour Area
Treatment Scheme (HATS) Stage I was commissioned in late 2001, the data shown
in Table 5.3Table
5.3Table 5.3Table 5.3Table 5.354.3 and Table 54.4 represent the situation
after the commissioning of HATS Stage 1.
Table 5.3Table 54.3 Summary Statistics of 2002 Marine Water
Quality in the Vicinity of the Macau Ferry Terminal
|
Parameter
|
|
EPD Monitoring Station
|
WPCO
WQOs (in marine waters)
|
|
VM5
|
VM6
|
VM7
|
|
Temperature (oC)
|
|
23.1
(16.3 - 27.4)
|
23.1
(16.3 - 27.4)
|
23.2
(16.4 - 27.5)
|
Not more than 2 oC in daily
temperature range
|
|
Salinity (ppt)
|
|
31.8
(29.1 - 33.3)
|
31.8
(28.7 - 33.2)
|
31.7
(28.7 - 33.2)
|
Not to cause more than 10% change
|
|
Dissolved Oxygen (DO)
(% saturation)
|
|
81.0
(65 – 104)
|
77.0
(67.0 – 92.0)
|
79.0
(68.0 – 103.0)
|
-
|
|
Bottom
|
73.0
(34 – 103)
|
69.0
(20.0 – 89.0)
|
71.0
(47.0 – 85.0)
|
-
|
|
DO (mg/L)
|
|
5.7
(4.6 – 6.9)
|
5.5
(4.7 – 6.3)
|
5.6
(4.6 – 7.0)
|
Not
below 4 mg/L for 90% of the samples
|
|
Bottom
|
5.2
(2.4 – 6.8)
|
4.9
(1.4 – 6.3)
|
5.1
(3.3 – 6.4)
|
Not
below 2 mg/L for 90% of the samples
|
|
pH value
|
|
8.0
(7.6 – 8.2)
|
7.9
(7.7 – 8.2)
|
7.9
(7.6 – 8.3)
|
6.5 -
8.5 (± 0.2 from natural range)
|
|
Secchi
disc (m)
|
|
2.0
(1.0 – 3.0)
|
1.9
(1.0 – 2.5)
|
1.7
(1.0 – 3.0)
|
-
|
|
Turbidity
(NTU)
|
|
10
(7.0 - 14.3)
|
10.4
(7.0 – 14.6)
|
10.2
(7.3 – 15.6)
|
-
|
|
Suspended
Solids (SS) (mg/L)
|
|
6.0
(3.2 – 13.3)
|
7.0
(3.4 – 17.0)
|
6.0
(3.9 – 10.1)
|
Not more
than 30% increase
|
|
Silica
(as SiO2)
(mg/L)
|
|
0.7
(0.1 – 1.4)
|
0.7
(0.2 – 1.4)
|
0.7
(0.3 – 1.3)
|
-
|
|
5-day
Biochemical Oxygen Demand (BOD5) (mg/L)
|
|
1.2
(0.5 – 2.4)
|
1.2
(0.7 – 2.3)
|
1.3
(0.5 – 3.1)
|
-
|
|
Nitrite
Nitrogen (NO2-N) (mg/L)
|
|
0.03
(0.01 – 0.05)
|
0.03
(0.01 – 0.05)
|
0.03
(0.01 – 0.05)
|
-
|
|
Nitrate
Nitrogen (NO3-N) (mg/L)
|
|
0.10
(0.04 – 0.17)
|
0.10
(0.04 – 0.21)
|
0.11
(0.06 – 0.21)
|
-
|
|
Ammonia
Nitrogen (NH3-N) (mg/L)
|
|
0.19
(0.05 – 0.42)
|
0.20
(0.06 – 0.42)
|
0.21
(0.06 – 0.41)
|
-
|
|
Unionised
Ammonia (UIA) (mg/L)
|
|
0.006
(0.003 – 0.010)
|
0.006
(0.003 – 0.010)
|
0.007
(0.003 – 0.011)
|
Not more
than annual average of 0.021 mg/L
|
|
Total
Inorganic Nitrogen (TIN) (mg/L)
|
|
0.31
(0.13 – 0.64)
|
0.33
(0.20 – 0.65)
|
0.34
(0.20 – 0.66)
|
Not more
than annual water column average of
0.4 mg/L
|
|
Total
Nitrogen (Total-N) (mg/L)
|
|
0.52
(0.30 – 0.90)
|
0.53
(0.36 – 0.84)
|
0.54
(0.46 – 0.87)
|
-
|
|
Ortho-Phosphate
(Ortho-P) (mg/L)
|
|
0.022
(0.007 – 0.040)
|
0.023
(0.009 – 0.040)
|
0.023
(0.009 – 0.038)
|
-
|
|
Total
Phosphorus (Total-P) (mg/L)
|
|
0.05
(0.03 – 0.08)
|
0.05
(0.03 – 0.07)
|
0.05
(0.04 – 0.07)
|
-
|
|
Chlorophyll-a
(µg/L)
|
|
4.8
(0.6 – 18.9)
|
4.2
(0.4 – 16.2)
|
4.2
(0.7 – 19.8)
|
-
|
|
E. coli
(cfu/100
mL)
|
|
4,500
(630 – 42,000)
|
5,000
(600 – 19,000)
|
4,600
(1,500 – 60,000)
|
-
|
|
Faecal
Coliform
(cfu/100
mL)
|
|
11,000
(1,400 – 70,000)
|
13,000
(2,000 – 70,000)
|
12,000
(4,100–180,000)
|
-
|
Note: 1. Except as specified, data presented are
depth-averaged values calculated by taking the means of three depths: Surface,
mid-depth, bottom.
2.
Data presented are annual
arithmetic means of depth-averaged results except for E. coli and faecal coliforms that are annual geometric means.
3.
Data in brackets indicate the
ranges.
Table 5.4Table 45.4 Summary Statistics of 2003 Marine Water
Quality in the Vicinity of the Macau Ferry Terminal
|
Parameter
|
|
EPD
Monitoring Station
|
WPCO WQOs (in marine waters)
|
|
VM5
|
VM6
|
VM7
|
|
Temperature
(oC)
|
|
23.4
(171 -
27.5)
|
23.5
(17.3 -
27.6)
|
23.5
(17.2 -
27.8)
|
Not more
than 2 oC in daily temperature range
|
|
Salinity (ppt)
|
|
32.1
(29.4 - 33.4)
|
32.0
(29.8 - 33.3)
|
31.0
(21.7 - 33.3)
|
Not to cause more than 10% change
|
|
Dissolved Oxygen (DO)
(% saturation)
|
|
75
(61 – 88)
|
74
(58 – 85)
|
76
(61 – 91)
|
-
|
|
Bottom
|
71
(53 – 88)
|
69
(44 – 85)
|
72
(55 – 91)
|
-
|
|
DO (mg/L)
|
|
5.3
(4.1 – 6.9)
|
5.3
(3.9 – 6.7)
|
5.4
(4.1 – 6.9)
|
Not
below 4 mg/L for 90% of the samples
|
|
Bottom
|
5.0
(3.7 – 6.9)
|
4.9
(3.1 – 6.7)
|
5.1
(3.8 – 6.8)
|
Not
below 2 mg/L for 90% of the samples
|
|
pH value
|
|
8.1
(8.0 – 8.2)
|
8.0
(7.9 – 8.2)
|
8.1
(7.9 – 8.2)
|
6.5 -
8.5 (± 0.2 from natural range)
|
|
Secchi
disc (m)
|
|
2.3
(1.5 – 4.1)
|
2.3
(1.5 – 4.0)
|
2.1
(1.3 – 3.2)
|
-
|
|
Turbidity
(NTU)
|
|
8.6
(5.4 - 11.0)
|
8.8
(5.4 – 12.2)
|
8.9
(4.7 – 14.2)
|
-
|
|
Suspended
Solids (SS) (mg/L)
|
|
4.7
(5.7 - 7.5)
|
5.1
(2.4 – 9.8)
|
5.8
(2.8 – 13.3)
|
Not more
than 30% increase
|
|
Silica
(as SiO2)
(mg/L)
|
|
0.8
(0.3 – 1.4)
|
0.9
(0.2 – 1.4)
|
1.0
(0.5 – 3.2)
|
-
|
|
5-day
Biochemical Oxygen Demand (BOD5) (mg/L)
|
|
1.4
(0.7 – 2.2)
|
1.1
(0.5 – 2.0)
|
1.2
(0.6 – 2.4)
|
-
|
|
Nitrite
Nitrogen (NO2-N) (mg/L)
|
|
0.03
(0.01 – 0.05)
|
0.03
(0.01 – 0.05)
|
0.04
(0.01 – 0.14)
|
-
|
|
Nitrate
Nitrogen (NO3-N) (mg/L)
|
|
0.11
(0.04 – 0.21)
|
0.11
(0.04 – 0.19)
|
0.16
(0.05 – 0.58)
|
-
|
|
Ammonia
Nitrogen (NH3-N) (mg/L)
|
|
0.20
(0.07 – 0.34)
|
0.20
(0.09 – 0.34)
|
0.21
(0.11 – 0.31)
|
-
|
|
Unionised
Ammonia (UIA) (mg/L)
|
|
0.009
(0.005 – 0.014)
|
0.009
(0.005 – 0.015)
|
0.009
(0.005 – 0.016)
|
Not more
than annual average of 0.021 mg/L
|
|
Total
Inorganic Nitrogen (TIN) (mg/L)
|
|
0.33
(0.22 – 0.50)
|
0.34
(0.25 – 0.50)
|
0.40
(0.28 – 0.93)
|
Not more
than annual water column average of 0.4 mg/L
|
|
Total
Nitrogen (Total-N) (mg/L)
|
|
0.52
(0.33 – 0.65)
|
0.52
(0.35 – 0.64)
|
0.58
(0.44 – 1.15)
|
-
|
|
Ortho-Phosphate
(Ortho-P) (mg/L)
|
|
0.036
(0.02 – 0.050)
|
0.037
(0.02 – 0.050)
|
0.037
(0.02 – 0.050)
|
-
|
|
Total
Phosphorus (Total-P) (mg/L)
|
|
0.06
(0.03 – 0.08)
|
0.06
(0.0 4 – 0.07)
|
0.06
(0.04 – 0.08)
|
-
|
|
Chlorophyll-a
(µg/L)
|
|
4.0
(0.3 – 22.7)
|
3.5
(0.4 – 16.7)
|
3.3
(0.3 – 15.6)
|
-
|
|
E. coli
(cfu/100
mL)
|
|
5,200
(640 – 42,000)
|
3,000
(250 – 14,000)
|
5,900
(500 – 22,000)
|
-
|
|
Faecal
Coliform
(cfu/100
mL)
|
|
12,000
(2,500 – 100,000)
|
7,000
(1,100 – 26,000)
|
14,000
(1,200–60,000)
|
-
|
Note: 1. Except as specified, data presented are
depth-averaged values calculated by taking the means of three depths: Surface,
mid-depth, bottom.
2.
Data presented are annual
arithmetic means of depth-averaged results except for E. coli and faecal coliforms that are annual geometric means.
3.
Data in brackets indicate the
ranges.
4.11 Full compliance with the WQO for
depth-averaged and bottom dissolved oxygen (DO), depth-averaged total inorganic
nitrogen (TIN) and unionised ammonia (UIA) was achieved at VM5, VM6 and VM7 in
2002.
4.12 In 2003, full compliance with the WQO for
depth-averaged and bottom DO, depth-averaged UIA was achieved at VM5, VM6 and
VM7. The compliance for depth-averaged
TIN was achieved at VM5 and VM6 only.
At VM7, the annual mean of depth averaged TIN marginally exceeded the
WQO (reference: EPD Publication “Marine
Water Quality in Hong Kong 2003”).
4.13 Figure 54.2 shows the existing
marine sensitive sites that may be affected by the Project. Key marine
sensitive sites include:
·
Saltwater intakes and cooling water intakes along the
seafront of Victoria Harbour
·
Coral and bird nesting sites at Green Island and
Little Green Island
·
Egretry site at Stonecutters Island
·
Various typhoon shelters and Public Cargo Working
Areas (PCWA)
4.14 Construction Phase
The potential impacts
from construction activities for the proposed expansion of the existing helipad
have been reviewed and assessed in Sections 45.17 15 to 45.1917. Water pollution control measures are
recommended in Sections 45.1825 to 45.32 24 to ensure that any
effluent discharged from the Project site would comply with the criteria of
WPCO.
Operational Phase
The locations of the existing marine refuelling
facilities and proposed new helicopter refuelling facilities are shown in
Figure 4.1. Background
information including description and operational details of the refuelling
facilities are provided in Chapter 2 as well as Sections 4.6 to 4.13. The physical and chemical properties
of jet fuel are described in Sections 4.15 to 4.16 and Section 5.21. Identification of hazardous
scenarios during operational phase covers storage, transfer and transhipment of
fuel within the MFT site. The
possible fuel spillage events, spill quantities and occurring frequency have
been identified in Table 4.6. Two possible
spill locations at the MFT have been identified in the hazard assessment, which
are the fuel unloading point and the fuel storage tank as shown in Figure 4.3. 5454. coastal developmentlikely likely Risks of
fuel spillage will be minimised through design and operational practice. Mitigation measures are recommended in
Section 4.7 to prevent and contain spillages from the Project. Potential water quality
impacts in case of fuel spillage will be managed through the emergency
contingency plan derived under this Project as well as the Maritime Oil Spill Response Plan (MOSRP) developed by the
Marine Department (MD). Identification and
Evaluation of Water Quality Impacts
Construction
Phase Water Quality Impact
Construction Activities
4.15 The proposed structural reinforcement for
the new landing pad on the roof-top of the Inner Pier of the MFT would be
carried out using existing pile caps on site and new piles supported by the
pier level. Marine piling works would
not be required and no dredging of marine sediment would be carried out for the
Project. The aluminium design for the
proposed new landing/take-off pad would be built on the existing rooftop of the
MFT Inner Pier. The aluminium trusses
would be built offsite and then transported to the MFT Pier by barge. The aluminium trusses would then be fixed on
site and connected to the existing pile cap.
There would not be any demolition of existing structures for the expansion
works. Excavation works would not be
required. It is also expected that the
installation of aluminium trusses at the existing pile cap would not impose any
water quality concern during construction and operational stages. The effects
on water quality from the possible provision of segregation facilities and
measures to accommodate domestic helicopter services and the possible expansion
of the existing helipad would be expected to be minimal with the implementation
of proper site drainage and good site practices.
Sewage from Workers
4.16 Based on the Sewerage Manual, Part I,
1995 of the Drainage Services Department (DSD), the sewage production rate for
construction workers is estimated at 0.35 m3 per worker per day.
For every 10 construction workers working simultaneously at the construction
site, about 3.5 m3 of sewage would be generated per day. The sewage should not be allowed to
discharge directly into the surrounding water body without treatment. Existing toilets within the MFT site could
be made available for use as necessary.
Sufficient chemical toilets should be provided for workers as
necessary.
Construction Runoff and Drainage
4.17 It is important that proper site practice
and good site management be followed to prevent contaminated run-off
from entering the surrounding waters.
With the implementation of appropriate measures to control
run-off and drainage from the construction site, disturbance of water bodies
would be avoided and deterioration in water quality would be minimal. Thus,
unacceptable impacts on the water quality are not expected, provided that the recommended
measures described in Sections 4.1825 to 4.32 24 are properly implemented.
Operational
Phase Impact due to Fuel Spillage
During the operational
phase, the likelihood of major spill events occurring would be very low. The water quality impact due to fuel spillage is considered to be adequately addressed
by the established MOSRP. Risks of
fuel spillage will be minimised through design and operational practice as
discussed in Section 4.7.
keroseneskerosene The properties of helicopter
fuel are given in Table 5.5. In the remote case that spillage occurs, the
associated water quality impact is considered minor and would be transient
only. Helicopter fuel, which
consists of light oil, is non-persistent and would not result in marine
pollution . The fuel would evaporate to the atmosphere in less
than 24 hours under typical temperate climate in Hong Kong .
Table 5.5 Properties
and Characteristics of Helicopter Fuel 6
|
Oil Type
|
Specific Gravity
|
Persistence
|
|
Light to medium distillate
|
|
Non-persistent
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Figure 5.1 shows the
locations of existing marine sensitive sites.
Two possible spill locations at the MFT have been
identified in the hazard assessment, which are the fuel unloading point and the
fuel storage tank as shown in Figure 4.3. The hazard assessment also considered spillage during marine
transport within 500m from the MFT site.
The distance between the fuel transportation route
and coastal development would likely be maximized to reduce any potential
hazard impact. Thus, within 500m from
the MFT site, a fuel delivery barge would likely approach the MFT from the
north.
Key marine sensitive receivers would be the
saltwater and cooling water intakes along the seafront of the Victoria Harbour,
in particular the WSD saltwater intakes at Sheung Wan and Central Water Front
that are closest to the possible spill locations. These
intakes are however well below the sea surface level and therefore would not be
easily damaged by the surface oil slick.
Impacts on the egretry at Stonecutters Island, coral and bird nesting
sites at Green Island, which are more than 2 km away from the Site, would be
considered insignificant. As under the influence of strong currents in Victoria
Harbour, any residual fuel patch remaining after the necessary oil response and
clean up operations under the MOSRP would likely have dissipated before
reaching these distant receivers.
In case of
any fuel spillage, the WSD saltwater intakes at Sheung
Wan and Central Water Front should be given priority
for protection. In any case, it is
important to predict the movement of the spill in order to decide which
sensitive receivers should be protected during the spill event. Surface
currents would dominate the movement of the spill unless the winds are
extremely strong. The wind will cause
the slick to move at approximately 3% of the wind speed, in the direction of
the wind 6. The surface flow patterns of
marine water in the Study Area in summer and winter under typical tidal
conditions are illustrated in Appendix 5.1. As shown in Appendix
5.1, the water within the Study Area would in general
flow either to the east or to the west depending on the tide condition. Priority
should be given to protect the sensitive sites downstream of the spill
location.
Construction Phase
Construction Site Runoff and General
Construction Activities
4.18 The practices outlined in ProPECC PN 1/94
Construction Site Drainage should be adopted where applicable, to minimise the
potential water quality impacts from construction site runoff and various
construction activities.
4.19 There is a need to apply to EPD for a
discharge licence for discharging effluent from the construction site, if any.
The discharge quality is required to meet the requirements specified in the
discharge licence. Any wastewater generated from the works areas should be
treated so that it satisfies all the standards listed in the TM-DSS. It is anticipated that the wastewater
generated from the works areas, if any, would be of small quantity.
4.20 Good site practices should be adopted to
collect the rubbish and litter on the construction sites so as to prevent the
rubbish and litter from spreading from the site area. It is recommended to clean the construction site on a regular
basis. Scavenging service for
collecting any materials/waste loss form the site into the sea should be
provided on a need basis.
Sewage from Workforce
4.21 The presence of construction workers
generates sewage. The construction
workers can make use of the existing toilet facilities within the MFT, as
necessary. If required, sufficient portable chemical toilets should be provided
in the works areas, and a licensed collector should be deployed for appropriate
disposal and maintenance of the toilets on a regular basis.
4.22 Notices should be posted at conspicuous
locations to remind the workers not to discharge any sewage or wastewater into
the nearby environment during the construction phase of the Project. Regular environmental audit on the
construction site can provide an effective control of any malpractices and can
achieve continual improvement of environmental performance on site. It is anticipated that sewage generation
during the construction phase of the Project would not cause water pollution
problem after undertaking all required measures.
Accidental Spillage of Chemicals
The
contractor must register as a chemical waste producer if chemical wastes would
be produced from the construction activities. The Waste Disposal Ordinance (Cap
354) and its subsidiary regulations, in particular the Waste Disposal (Chemical
Waste) (General) Regulation, should be observed and complied with for control
of chemical wastes.
4.23 Any service shop and maintenance
facilities should be located within a bunded area, and sumps and oil
interceptors should be provided. Maintenance of equipment involving activities
with potential for leakage and spillage should only be undertaken within the
areas appropriately equipped to control these discharges.
Disposal
of chemical wastes should be carried out in compliance with the Waste Disposal
Ordinance. The Code of Practice on the Packaging, Labelling and
Storage of Chemical Wastes
published under the Waste Disposal Ordinance details the requirements to deal
with chemical wastes. General requirements are given as follows:
·Suitable
containers should be used to hold the chemical wastes to avoid leakage or
spillage during storage, handling and transport.
·Chemical
waste containers should be suitably labelled, to notify and warn the personnel
who are handling the wastes, to avoid accidents.
·Storage
area should be selected at a safe location on site and adequate space should be
allocated to the storage area.
Operational Phase
Handling of Site Drainage and
Effluent
4.24 For handling, treatment and disposal of
operational stage effluent, the practices outlined in ProPECC PN 5/93 should be
adopted where applicable. The following
relevant recommendations should be followed:
·
Drainage
outlets provided in open areas and areas subjected to a substantial amount of
wind-blown rain should be connected to storm drains.
·
Drainage
outlets provided in covered areas, including covered podiums and other roofed
areas, should be discharged to foul sewers.
·
Surface
water drainage should be provided for discharging storm water from open
surfaces. Such drainage as normally
collected in open surface channels should be led to storm water drains via silt
removal facilities. Runoff in channels
of building platforms should pass through a gully pit with necessary gratings
to prevent objects from entering the storm water drains.
Emergency Contingency Plan
To provide a mechanism to
minimise the impact of fuel spill, an emergency contingency plan has been
formulated in Sections 5.535 to 5.641 below.
Communication
Facilities
Good
communications or telecommunications are vital for efficient management of the
spill response. It is important to
ensure that vessels, helicopters and site supervisors are equipped with proper
telecommunication equipment such as portable radiotelephones and cellular
telephones so that they can talk to each other for managing the responses to
the ever-changing conditions of a spill.
Communication
Paths and Reporting Procedures
The supervisor(s) of the
refuelling facility (in case of fuel spill from MFT) or operator(s) of the
relevant fuel delivery vessel (in case of fuel spill from ship) should closely
communicate with the MD and other relevant departments. A list of key personnel contacts should be
provided to the refuelling facility/vessel operator(s) for effective
communication. The list of contacts
should include the telephone numbers of responsible personnel in the MD and
other relevant parties such as the Water Services Department (WSD),
Agricultural, Fisheries and Conservation Department (AFCD), as well as the
owners or operators of the individual cooling water intakes that are
potentially affected by the Project. Close communication with WSD and
individual intake operators is
considered to be one effective means to minimize any impact on the intake
systems. Should it
appear necessary, WSD and/or individual intake
operators may consider shutting down the relevant pumping
station for a short period of time in order to minimize any adverse
impacts. If any
potential impact on the coral and bird nesting sites at Green Island or the
egretry site at Stonecutters Island is foreseen, AFCD should be informed. The telephone list should be updated at regular
intervals to incorporate any future sensitive sites.
Any spill
event should be reported to the pollution control unit of the MD at the
earliest opportunity. The refuelling
facility/vessel operator(s) should record as much of the information listed
below as possible.
Date and
time of spillage event/sighting of the fuel spill
Location
(Position in Latitude/Longitude, and/or description using recognised names)
Source of
spill
Cause of
spill
In case of
a ship spill, the name and type of vessel(s) involved, information on whether
grounding or collision has occurred should be provided.
If the
spill is released from an oil storage installation (OSI), the name and location
of the OSI should be provided.
Type and
estimated quantity of oil spilled and likelihood of further spillage
Description
of the oil slicks, including direction of movement, length, breadth and
appearance
Action,
both taken and intended, to combat pollution and to prevent further spillage
Whether
the leak or spill has been stopped at the source
Name of person
reporting the incident and how he can be
re-contacted
This
information should be provided to the MD for effective management of the spill
event under the MOSRP.
Spill
Cleanup
Any spill
event will be systematically responded through the MOSRP. The guidelines for cleaning up of oil
spills are given in Section 5.5 of the MOSRP.
The clean up operation is to be carried out by the MD with the support
from other relevant departments or organizations as described in the
MOSRP. The Project Proponent should
consider maintaining some anti-oil pollution
equipment on site, such as floating oil booms, absorbent materials and
skimmers, as supplements to MD’s equipment for efficient oil response.
The operation staff of the
Project should not be directly involved in any oil combating activity, unless
the relevant personnel are protected by appropriate safety clothing/equipment
and are fully trained with the oil combating knowledge as discussed in Section
6 of the MOSRP so as to minimize
the potential safety and health risks.
Training
It is important that
periodic training should be provided for the operation staff of the Project to
get familiar with the oil response and clean up procedures derived in the
MOSRP, as well as the communication paths and reporting procedures in the event
of fuel spill.
4.25 With the implementation of appropriate
mitigation measures recommended in Sections 4.1825 to 4.24, no
adverse residual impact would be expected during both construction phase and operational
phase.
4.26 The construction phase water quality
impact would be temporary and localised during construction. No unacceptable residual water quality
impacts would be expected from the Project, provided that all the recommended
mitigation measures are properly implemented.