10.1.1
This
Section of the report presents the findings of a hazard assessment for the
Draft RODP developed in the NLDFS in accordance with Study Brief Clause 6.2 (c)
(xii). No risk comment is required for
construction or operation of CKWLR.
10.1.2
The
findings on Hazard to Life contained in this section are based on previous
hazard assessment studies since the proposed developments do not contribute to
any significant increase in population in the vicinity of existing and proposed
hazardous installations.
10.2.1
The EIA
Ordinance requires that the risks associated with developments in the vicinity
of potential sources of hazard to population (e.g. Dangerous Goods storage
facilities) comply with the Risk Guidelines in Annex 4 of the EIAO TM. This is demonstrated through the undertaking
of a risk assessment.
10.2.2
Section 4 of Chapter 11 of the Hong
Kong Planning Standards and TMGuidelines requires that any new development
within the consultation zone of a Potentially Hazardous Installation must
comply with the Risk Guidelines
10.3.1
Within the
NLDFS Study Area, there are various potential sources of hazard which may pose
a constraint on future development of the area. These are listed below:
·
Siu Ho Wan Water Treatment Works (WTW), which is
classified as a Potentially Hazardous Installation (PHI);
·
the chlorine unloading jetty associated with the
WTW (near the North Lantau Refuse Transfer Station);
·
the planned Tang Lung Chau Dangerous Goods
Anchorage (DGA);
·
Dangerous Goods (DG) marine traffic through the
Kap Shui Mun Fairway;
·
the Towngas high pressure gas pipeline which has
a landfall at the Luk Keng headland and runs along the North Lantau coast to
Tai Ho; and
·
the development of the Theme Park at Penny’s Bay
which will store and use fireworks and sodium hypochlorite. This includes the
loading /unloading quay for the fireworks and the sodium hypochlorite.
10.3.2
The impacts
from the above hazard sources on the proposed Draft RODP for NLDFS are
discussed in the following paragraphs.
siu ho wan wtw
10.4.1
Siu Ho Wan
WTW is classified as a Potentially Hazardous Installation (PHI) on account of
storage of hazardous chemical chlorine in one tonne drums. The Consultation
Zone for WTWs classified as PHIs is 1km. Any new development with sizeable
population increase within the Consultation Zone requires a Hazard Assessment
to demonstrate that the risks due to the new development are acceptable in
accordance with the Risk Guidelines.
10.4.2
A Hazard
Assessment of Siu Ho Wan WTW (including the chlorine unloading jetty) was
carried out in 1992(). This assessment considered both existing and
planned population in the vicinity of the WTW and the jetty.
10.4.3
The
proposed NLDFS developments within the Consultation Zone do not contribute to
any significant increase in population from that assumed in the 1992 Hazard
Assessment Study. The draft RODP does not propose any residential or sensitive
uses within the consultation zone of the WTW.
10.4.4
The only
new development with increase in population will be the promenade linking an
Eco-Park about 2 km north-east of Siu Ho Wan WTW to Tai Ho new town. The
promenade passes by the chlorine unloading jetty and, at its closest point of
approach, lies about 400 m from Siu Ho Wan WTW. The promenade may include cycle ways.
10.4.5
The
population()
on the promenade will however, be transient population and the total number is
expected to be less than 500.
10.4.6
Considering
the above, the additional risks due to the NLDFS developments within the
Consultation Zone of Siu Ho Wan WTW are not considered to be significant.
10.4.7
It is noted
that, since completion of the 1992 Hazard Assessment, WSD are considering
uprating Siu Ho Wan WTW, which may involve additional chlorine storage and
usage. The Project Profile submitted to EPD suggests an increase in storage and
usage of chlorine from the current amount of 73 tonnes to 84 tonnes(). The upgrading of the Siu Ho Wan WTW would
require a separate EIAO application and if the upgrading works require an
increase in chlorine storage, a separate hazard assessment will also be
required.
Potential
Tang Lung Chau Dangerous Goods Anchorage
10.4.8
The
potential Tang Lung Chau DGA is proposed to be located approximately 200 m to
the south-east of Ma Wan and will be approximately 1 km by 600 m in overall
dimension, as shown on Figure 2.4e. The DGA will be protected by breakwaters
with two entry/exit points into the Ma Wan Fairway. The DGA is proposed to have 72 moorings and is proposed to be
open 24 hours a day for use by DG vessels, whether laden or empty.
10.4.9
The
potential Tang Lung Chau DGA will replace the existing Tsuen Wan DGA. A Hazard Assessment for the new DGA was
carried out in 1995(),
which assessed the risks posed by the proposed DGA to nearby population,
including future development. The
populations considered were principally those associated with the nearby
shipping channels and the island of Ma Wan.
10.4.10The Draft RODP shows that the nearest
development (the proposed Tsing Chau Tsai reclamation on the north-east coast
of North Lantau) lies 500 m from the proposed DGA. The maximum effect distance for incidents arising at the DGA was
assessed in the 1995 study to be 152 m (distance to 3% probability of fatality
for a fireball due to an incident involving a DG category 5 material coming
into contact with a red hot hull following an explosion). Therefore the presence of the DGA poses no
constraint to the Tsiing Chau Tsai reclamation as
envisaged.
Dangerous
Goods Marine Traffic
10.4.11The Kap Shui Mun Fairway passes between
the proposed Tang Lung Chau DGA and the proposed Tsing Chau Tsai reclamation on
the north-east coast of North Lantau.
The Ma Wan Fairway/Kap Shui Mun Fairway serve as routes for a number of
DG marine traffic to destinations in the Mainland, as well as to the Aviation
Fuel Receiving Facility at Sha Chau.
10.4.12A small portion of the proposed Tsing
Chau Tsai reclamation in the north-east comes within 350m of the Kap Shui Mun
Fairway. The remaining part of the reclamation is further away. Also, the number of vessel movements in the
Kap Shui Mun Fairway is low as most of the DG vessels to and from the proposed
Tang Lung Chau DGA and mainland China would use the Ma Wan Fairway
10.4.13Hence, the marine DG traffic through the
Kap Shui Mun Fairway is not expected to pose any significant risks to the
development on the shoreline of the proposed Tsing Chau Tsai reclamation.
Towngas
High Pressure Gas Pipeline
10.4.14The Towngas high pressure gas pipeline
has a landfall on the eastern side of the Luk Keng headland, where there is a
offtake and pigging station. The
pipeline then runs along the North Lantau coast to Tai Ho, where there is
another offtake and pigging station.
The pipeline contains Towngas (a mixture of 48% hydrogen, 29% methane,
20% carbon dioxide and 3% carbon monoxide) at a pressure of up to 35 barg.
10.4.15Based on the previous Hazard Assessment
Study()
for high pressure gas pipelines the distance over which restrictions may apply
may be taken as 60 m corresponding to the fireball radius following ignition of
a release from full-bore rupture of the pipeline. Any high density development, e.g. high rise residential or
commercial development, if proposed to be located within this zone should be
subject to a hazard assessment study.
10.4.16The proposed NLDFS Draft RODP has no high
rise residential nor commercial location within 60 m from the pipeline, and,
therefore, the existing pipeline poses no constraint to the Draft RODP
developments.
Proposed Risk to Life from the Theme Park
and Associated Developments at Penny’s Bay
10.4.17The proposed Theme Park in Penny’s Bay
comprises an EIAO Designated Project and will involve storage, transport and
use of fireworks and sodium hypochlorite.
A Risk to Life Assessment on this has been carried out as part of the
Schedule 2 Theme Park EIA and associated developments and is summarised below.
10.4.18The assessment includes the
loading/unloading quay for dangerous goods (fireworks and sodium hypochlorite),
storage and use on site and the hazards posed by them. The fireworks and sodium
hypochlorite will be stored in “back of house” area restricted to public
access. The fireworks and sodium hypochlorite deliveries will be made in the
night when the Theme Park will be closed to the public.
10.4.19High safety standards and operating
practices will be adopted by the Theme Park operator. These are presented in
the Theme Park EIA.
10.4.20The risk to life due to fireworks and
sodium hypochlorite storage, transport and use were found to be in the
‘acceptable’ region of the Hong Kong Risk Guidelines.
10.5.1
Based on
the identification of hazard sources within the NLDFS Study Area, the proximity
of the proposed NLDFS developments to these hazard sources and the additional
population due to the proposed NLDFS developments, it is found that the proposed
developments considered in the Draft RODP do not contribute to any significant
increase in overall risks from the hazard sources. The impact summary is
included in Table 10.5a.
10.5.2
It is,
therefore, concluded that the Draft RODP are compatible with Hong Kong Risk
Guidelines and are feasible from hazard to life considerations.
Table10.5a - Impact Summary Table
|
Issue
|
Operational Impact
|
|
Assessment
Points
|
Population
within the NLDFS Study Area
|
|
Relevant
Criteria
|
Societal
and Individual Risk Guidelines in Annex 4 of EIAO TM
|
|
Potential
Impacts
|
See
Hazard Assessment of Theme Park EIA
|
|
Mitigation
Measures
|
See
Hazard Assessment of Theme Park EIA
|
|
Residual
Impacts
|
Acceptable
|
|
Environmental
Acceptability
|
Acceptable
|