13.
Hazard to Life
13.1
Introduction
13.1.1.1 This section of the EIA presents the analysis and findings of the Hazard to Life Assessment undertaken for the Project.
13.1.1.2 In accordance with Section 3.4.14 of the EIA Study Brief (ESB-360/2023), a hazard to life assessment should be conducted to evaluate the risks from dangerous goods (DG) due to the existing and/or planned hazardous facilities, including but not limited to the planned desalination plant at TKO 137, town gas pipeline, synthetic natural gas production plant, LPG filling stations, explosive off-loading pier, and potential biogas production and storage at the proposed effluent polishing plant, during both construction and operation phases of the Project.
13.1.1.3 In addition, a review of the risks from the use, transport and overnight storage of explosives (if any) during construction and operation of the Project should be conducted, and assess if risk to life is a key issue with respect to Risk Guidelines given in Annex 4 of the TM. QRA for the use, transport and overnight storage of explosives for the Project shall be conducted if, and only if, risk to life is a key issue with respect to Risk Guidelines following the requirements in Section 12.1 of the TM.
13.1.1.4
The
locations of hazardous facilities that were assessed with respect to the
Project Site are shown in Plate 13‑1. Furthermore, it is confirmed that all the proposed facilities
in TKO 132 have been reviewed and no risks from dangerous goods due to existing
and/ or planned hazardous facilities in TKO 132 are identified.
Plate 13‑1 Locations of Hazardous Facilities and Project Layout
13.2
Environmental
Legislation, Standards and Guidelines
13.2.1.1 As set out in Annex 4 of the EIAO-TM, the criterion for hazard to life specifies the Individual and Societal Risk Guidelines. The Hong Kong Government Risk Guidelines (HKRG) per the EIAO TM Annex 4 states that the individual risk is the predicted increase in the chance of fatality per year to an individual due to a potential hazard. The individual risk guidelines require that the maximum level of off-site individual risk should not exceed 1 in 100,000 per year i.e. 1×10-5 per year. Societal risk expresses the risks to the whole population. It is expressed in terms of lines plotting the cumulative frequency (F) of N or more deaths in the population from incidents at the installation. Two F-N risk lines are used in the HKRG that demark “Acceptable” or “Unacceptable” societal risks. To avoid major disasters, there is a vertical cut-off line at the 1,000 fatality level extending down to a frequency of 1 in a billion years. The intermediate region indicates the acceptability of societal risk is borderline and should be reduced to a level which is “as low as reasonably practicable” (ALARP). It seeks to ensure that all practicable and cost-effective measures that can reduce risk are considered. The HKRG is presented graphically in Plate 13‑2.
Plate 13‑2 Societal Risk Guidelines
13.3
Study Objectives and
Methodology
13.3.1.1 The Hazard to Life Assessment requirements for the hazardous facilities and explosives as detailed in Appendix L of the EIA Study Brief are shown below:
(a)
Identify hazardous scenarios and then determine a
set of relevant scenarios to be included in a Quantitative Risk Assessment
(QRA);
i.
For hazardous facilities: Hazard scenarios
associated with the manufacture, on-site transport, storage and use of
dangerous goods in the hazardous facilities;
ii.
For Explosives: Hazardous scenarios associated with
the use, transport and overnight storage of the explosives.
(b)
Execute a QRA of the set of hazardous scenarios
determined in (a), expressing population risks in both individual and societal
terms;
(c)
Compare individual and societal risks with the
criteria for evaluating hazard to life as stipulated in Annex 4 of the TM; and
(d)
Identify and assess practicable and cost-effective
risk mitigation measures to demonstrate the compliance
with the Risk Guidelines.
13.3.1.2 This assessment consists of the following six main tasks:
(a)
Data / Information Collection and Update: collect relevant data / information that is
essential for the hazard assessment;
(b)
Hazard Identification: identify credible set of hazardous
scenarios associated with the operation of the hazardous facilities /
explosives;
(c)
Frequency Estimation: estimate the frequencies of the identified
hazardous scenarios by using Fault Tree and Event Tree Analysis;
(d)
Consequence Analysis: analyse the consequences of the identified
hazardous scenarios by using the well-established and widely accepted model,
e.g. SAFETI, ESTC;
(e)
Risk Assessment and Evaluation: evaluate the risks associated with the
identified hazardous scenarios. The evaluated risks will be compared with HKRG
to determine their acceptability. Where necessary, risk mitigation measures
will be identified and assessed to comply with the ALARP principle used in the
HKRG; and
(f)
Identification of Mitigation Measures: review the recommended risk mitigation
measures from previous studies, practicable and cost-effective risk mitigation
measures will be identified and assessed as necessary. The risk outcomes of the
mitigated case will then be reassessed to determine the level of risk
reduction.
13.3.1.3 According to the latest design, it is confirmed that the use, transport and overnight storage of explosives is not required for the Project, therefore, risk assessment associated with explosives related issue is not required.
13.3.1.4 In consultation with the Hong Kong and China Gas Company Limited, medium pressure town gas pipeline will be enough for both TKO 132 and 137 development, no high pressure town gas pipeline is anticipated and thus risk assessment associated with town gas pipeline is considered to be not necessary.
13.3.1.5 With reference to Section 5 of Appendix L of the EIA Study Brief, the methodology adopted in the risk assessment associated with planned desalination plant at TKO 137 is consistent with previous studies having similar issues (e.g. EIA study of the Desalination Plant at Tseung Kwan O (EIA Register No. AEIAR-192/2015) and Detailed Design Plan for Chlorine and Carbon Dioxide Storage of Desalination Plant).
13.4
Risk Assessment
Associated with Planned Desalination Plant at TKO 137
13.4.1.1 The risk results for the planned desalination plant associated with chlorine, sulphur dioxide and liquid carbon dioxide hazards are detailed in Appendix 13.1. The maximum individual risk (IR) is found to be 1×10-7 per year, which is confined within the boundary of the desalination plant. Given the off-site individual risk does not exceed 1×10-5 per year, the level of individual risk posed by the operation of the facility to the surrounding population is considered acceptable and in compliance with the HKRG. In addition, the societal risks fall within the “Acceptable” region in both assessment years, while the potential loss of life (PLL) for the facility were found to be about 2.5×10-6 and 2.0×10-6 per year for year 2035 and 2041 respectively.
13.5
Risk Assessment
Associated with Existing Synthetic Natural Gas (SNG) Production Plant
13.5.1.1
The risk results for the existing SNG production
plant are detailed in Appendix
13.2. The 1×10-5 per year contour is
confined within the boundary of the SNG production plant. Given that there is
no off-site risk with frequency greater than 1×10-5 per year, the
level of individual risk posed by the operation of the facility to the
surrounding population is considered acceptable and in compliance with the
HKRG. In addition, the
societal risks fall within the “Acceptable” region in both assessment years,
while the potential loss of life (PLL) for the facility were found to be about
2.6×10-8 per year and 2.3×10-8 per year for year 2030 and
2041 respectively.
13.6
Risk Assessment
Associated with Explosive Off-loading Pier
13.6.1 Background
13.6.1.1
The
explosives off-loading pier (pier) is located on the southeast corner of TKO
137, it is currently operated by Mines Division of Civil Engineering and
Development Department (CEDD). The Pier is used for the explosives delivery
operation from the Government Explosives Depot at Kau Shat Wan, Lantau, to
projects throughout the HKSAR. The pier
will be relocated before the first population intake at the northern part of
TKO 137 in 2030, and there will be no manufacture,
storage or use of dangerous goods in the explosives off-loading pier
accordingly.
13.6.1.2
According
to the latest available information from CEDD, the pier may be retained
supplying explosives to support the developments within the area under other
projects, till end of 2029. The pier
will be decommissioned and relocated thereafter.
13.6.2 Evaluation of Risk Implications Associated with Operation of Explosives Off-loading Pier
13.6.2.1
The
development of the Project is divided into several phases. Details of the site phasing plan please refer
to Appendix 2.3 of Section 2. The construction activities of the Project
will be commenced in phases, starting from Phase A at the northern portion of
the development site in Q4 2025, to Phase J at the southern portion of the development
site in Q4 2031.
13.6.2.2 Under the EIA study of the Desalination Plant at Tseung Kwan O (EIA Register No. AEIAR-192/2015), a QRA was carried out to investigate the feasibility of coexistence of the pier and the proposed desalination plant. The Environment Review Report (ERR) carried out in 2017 for the Desalination Plant shows the individual risk contour plot associated with the pier down to 1E-06 per year, it also stated that the hazard distance of 1% fatality probability for the explosives unloading operation is 161m. According to Figure 11.18 of the ERR, the individual risk contour 1E-06 per year will not encroach into the boundary of this Project.
13.6.2.3
Further,
the development sites of the Project closest to the pier will be developed in
Phase J, in which any construction activities will be commenced no earlier
than December 2031 and the earliest population intake of this phase is 2035.
There will be no construction activities within the 1% fatality
probability for the explosives unloading operation (i.e. 161m from the pier) before the
decommissioning and relocation of the pier, operation of the pier will have no
risk implication on the Project during both construction and operation phases.
Plate 13‑3 Individual Risk Contours of the Pier
