Annex H. Quantitative Risk Assessment Specialist Report

Transcription

1 Annex H Quantitative Risk Assessment Specialist Report

2 Burgan Oil Cape Terminal Major Hazard Installation Risk Assessment for EIA v4.0 Ref: MHI 0012

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4 EXECUTIVE SUMMARY Burgan Oil Cape Terminal wishes to construct a fuel receiving, storage and distribution terminal (hereafter referred to as the facility or the site ) on the Eastern Mole Berth in Cape Town Harbour. It is understood that Burgan Oil will operate the terminal on behalf of major oil companies. The site is intended to store petrol and diesel of various grades as well as additives such as ethanol and Bio Fame to supplement the petrol and diesel supply. The site will receive fuel from ships and ethanol and Bio Fame from road tankers. The site will then fill road tankers. Burgan Oil Cape Terminal identified this proposed bulk storage and handling of flammable liquids as having the potential to affect the health and safety of employees as well as members of the public in the event of a major incident. Hence there is a need to manage the risks and ensure compliance with the MHI Regulations promulgated under the Occupational Health and Safety Act No. 85 of 1993 which were revised in The current Major Hazard Installations Regulations are attached in ANNEX B. The proposed Burgan Oil Cape Terminal site is intended to be located on Portside Road on the Eastern Mole Berth in the Cape Town Harbour, Western Cape (GPS coordinates in decimal degrees: , ). The site is intended to have two primary, separate operating areas. A storage area will be located to the north western end of the mole while the road tanker loading gantry is located further to the south east. A bulk heavy oil storage terminal belonging to FFS Refiners (Pty) Ltd is located between the two proposed Burgan Oil site areas. The two areas are linked by aboveground product pipelines. The land-use surrounding the site can be summarised as follows: Both Berth 1 and Berth 2 are located on the south western side of the mole and therefore south west of both the storage tanks and the gantry loading facility. At the end of the mole, between Berth 1 and the proposed storage tanks in Bund B, the winch cable storage building is located. Also located on the mole is the FFS Refiners (Pty) Ltd site which is situated between the proposed Burgan Oil storage site and road loading gantry bays. FFS Refiners (Pty) Ltd is located on the south west side of the mole with part of the FFS Refiners (Pty) Ltd storage located between the proposed gantry bay and Berth 2. In addition the site intends to install an import pipeline to receive product from the Chevron Refinery via the Chevron Refinery white oils pipeline. The Burgan Oil pipeline will either terminate at Tanker Berth 2 or at the Chevron Refinery import manifold at the Chevron Joint Bunkering Services (JBS) fuel terminal. Due to the nature of the harbour and mole design, other industrial sites within the harbour are located outside the largest consequence distance and are therefore judged to be not affected in the event of a major incident at the Burgan Oil Cape Terminal site. i

5 Important Surrounding sites: FFS Refiners (Pty) Ltd located adjacent to the site, separated by a service corridor Chevron Joint Bunkering Services (JBS) Fuel Terminal Major transport routes in close proximity to the site: Portside Road is the primary access road to the Eastern Mole Berth. The following Major Hazard Installations have been identified to be near the site: FFS Refiners (Pty) Ltd located adjacent to the site, separated by a service corridor Chevron Joint Bunkering Services (JBS) Fuel Terminal The aim of the project was to undertake a Quantified Major Hazard Installation (MHI) Risk Assessment of the Cape Town Harbour site, with the objective to assess the risk to people off site via the Land Use Planning (LUP) and Fatality approaches. ERM have assumed that the proposed development will comply with world class standards of design, construction and operation. We would also recommend that the site considers implementing all of the recommendations which arose from the incident at the Buncefield Terminal in the United Kingdom in 2005 contained in the UK HSE Process Safety Leadership Group Final Report entitled Safety and Environmental Standards for Fuel Storage Sites. LOCATION SPECIFIC INDIVIDUAL RISK Figure 1 represents the location specific individual risks (LSIR) for hypothetical persons located outdoors (including Buncefield scenarios). Beyond the 1 cpm contour risks are considered broadly acceptable. Between the 1 cpm contour and the 10 cpm contour, the risks to the public are considered tolerable, so long as they can be demonstrated by Burgan Oil Cape Terminal to be as low as reasonably practicable (ALARP). The 100 cpm contour extends off site to a maximum of 10 m but does not envelope any of the surrounding sites. The risk to the workers in the adjacent facilities does not exceed 100 cpm. Therefore the risks are not considered intolerable according to the assessment criteria of Section There is a 1,000 cpm contour at the loading gantry. According to the assessment criteria in Section this would be deemed intolerable, however the actual individual risk experienced by workers in this area will be less as these workers are not on site 100% of the time. A typical gantry operator is understood to work for 40 hours per week and 48 weeks per year. This leads to an occupancy factor of 21.9%. The maximum risk within the gantry area is ii

6 1800 cpm. Therefore the actual individual risk experienced by operators is approximately cpm. This level of individual risk is therefore below 1000 cpm and can be deemed to not be intolerable according to the assessment criteria. Figure 2, represents the LSIR for persons located indoors (including Buncefield scenarios). Beyond the 1 cpm contour risks are considered broadly acceptable. Between the 1 cpm contour and the 10 cpm contour, the risks to the public are considered tolerable, so long as they can be demonstrated by Burgan Oil Cape Terminal to be as low as reasonably practicable (ALARP). The 100 cpm contour extends off site to a maximum of 10 m but does not envelope any of the surrounding sites. The risk to the workers in the adjacent facilities does not exceed 100 cpm. Therefore the risks are not considered intolerable according to the assessment criteria of Section The 1000 cpm contour is only reached in the vicinity of the loading gantry. As no structures exist in this area the assessment criteria in Section are not applicable. Additional Pipeline options were included and found not to alter the individual risk contours shown in Figure 1 and Figure 2. iii

7 Figure 1 Location Specific Individual Risks of Fatality Contours for Persons Located Outdoors (Including Buncefield Scenarios) 4

8 Figure 2 Location Specific Individual Risks of Fatality Contours for Persons Located Indoors (Including Buncefield Scenarios) 5

9 Societal Risk The calculated societal risk results for off-site populations (i.e. excluding known Burgan Oil on site population) as a result of risks posed by the site (including Buncefield) scenarios are shown in Figure 3. Figure 3 Societal Risk for the Burgan Oil Off Site Populations Including Buncefield Scenarios Burgan Oil Intolerable Broably Acceptable 100 F (cpm) N As illustrated by Figure 3 in the sites current proposal the societal risk F-N curve lies below the Broadly Acceptable indicator line and therefore also below the intolerable line with Buncefield Scenarios included. vi

10 Land Use Planning Location specific Individual Risk Figure 4 represents the location specific individual risks (LSIR) of dangerous dose for hypothetical persons located outdoors (including Buncefield scenarios) for Land Use Planning (LUP). As shown in Figure 4, the risk consultation distance (i.e. the 0.3 cpm contour), as referred to in Section 6.3.1, measured from the site boundary extends off-site to the west partly enveloping the winch cable store and to the south east of the storage area partly enveloping the FFS Refiners (Pty) Ltd site as well as over the edge of the mole to the north. The middle zone (1 cpm contour) follows the same trend as the 0.3 cpm contour to the north but does not extend so extensively over the FFS Refiners (Pty) Ltdsite and Berth 2. The 10 cpm (inner zone) contour extends off site and follows similar trend to the 1 cpm contour but a reduced amount towards the north and the area surrounding the road loading gantry. Using the criteria outlined in Section it has been shown that the Burgan Oil site falls within the Don t Advise Against DAA category for all 3 probability of dangerous dose zones as the only other sites enveloped by any of the contours are industrial sites. Restrictions on future development around the site should be enforced based on the LUP criteria explained within the report. Risk contours shown in Figure 4 should be compared against the criteria to deem if any proposed future development falls into the Advise Against AA or Don t Advise Against DAA category. If the development falls within the Advise Against AA category the proposed development cannot be continued. The inclusion of pipeline Option A extends the risk consultation distance (i.e. the 0.3 cpm contour) around the proposed pipeline layout as shown in Figure 5. The inclusion of pipeline Option A extends the risk consultation distance (i.e. the 0.3 cpm contour) around the proposed pipeline layout as shown in Figure 6. Both proposed pipelines do not affect the conclusion of the Land Use Planning assessment and the site still falls within the Don t Advise Against DAA category for all 3 probability of dangerous dose zones. Restrictions on future development around the site should be enforced based on the LUP criteria explained within the report. Risk contours shown in Figure 5 and Figure 6 should be compared against the criteria to deem if any proposed future development falls into the Advise Against AA or Don t Advise Against DAA category. If the development falls within the Advise Against AA category the proposed development cannot be continued. vii

11 Figure 4 Location Specific Individual Risks of Dangerous Dose Contours Land Use Planning

12 Figure 5 Location Specific Individual Risks of Dangerous Dose Contours with Pipeline Option A Land Use Planning

13 Figure 6 Location Specific Individual Risks of Dangerous Dose Contours with Pipeline Option B Land Use Planning

14 CONCLUSIONS The societal risk posed by the site is concluded to be broadly acceptable. The individual risk of fatality was found to not be intolerable but only tolerable if proved to be ALARP. In accordance with Section (5)(a) of the MHI Regulations shown in Annex B it is the opinion of ERM as an AIA that Burgan Oil have shown a commitment to the reduction of tank overfill events which could potentially result in a Buncefield type incident. This is highlighted in their Operating and Control Philosophy as shown in Annex F and their letter of commitment to this philosophy as shown in Annex G. Further, it is the opinion of ERM that the measures proposed in the Operating and Control Philosophy show a reasonable degree of risk reduction for this stage of the Burgan Oil fuel terminal design process as specific overfill prevention technologies have been accounted for. As such the individual risk of fatality posed by the proposed site can be considered as low as reasonably practicable (ALARP) for this stage of the design process and therefore tolerable as stated in the criteria in Section To verify this view, following completion of the Burgan Oil final design, an update of the current MHI risk assessment taking into account the final design overfill prevention measures must be carried out. Considering the surrounding land uses and using the criteria outlined in Section it has been shown that the proposed Burgan Oil site falls within the Don t Advise Against DAA category for all 3 probability of dangerous dose zones as the only other sites enveloped by any of the land use planning contours are industrial sites. Restrictions on future development around the site should be enforced based on the LUP criteria explained within the report. Environmental Resources Management Southern Africa (Pty) Ltd would declare the proposed Burgan Oil Cape Terminal which will be located at Portside Road, Eastern Mole Berth, Western Cape (GPS coordinates in decimal degrees: : , ) will be a Major Hazard Installation (MHI) as outlined in the current legislation. As a result of being declared a MHI, the Requirements of the MHI Regulations must be followed completely to ensure the proposed Burgan Oil Cape Terminal is legally compliant. Copies of this risk assessment must be submitted to the Local Provincial Director of the Department of Labour, the Chief Inspector of the Department of Labour Head Office in Pretoria and the Local Authorities. xi

15 CONTENTS 1 INTRODUCTION GENERAL INTRODUCTION REQUIREMENTS OF THE MHI REGULATIONS 3 2 RISK ASSESSMENT & MANAGEMENT METHODOLOGY DEFINITIONS PROCESS OF RISK MANAGEMENT HAZARD IDENTIFICATION CONSEQUENCE ANALYSIS Harm Criteria for Consequence Analysis Consequence Modelling FREQUENCY OF MAJOR ACCIDENT HAZARDS RISK CALCULATION RISK ASSESSMENT 9 3 ENVIRONMENTAL SITE SETTINGS SITE LOCATION METEOROLOGY REQUIREMENTS OF OTHER ENVIRONMENTAL LEGISLATION 15 4 DESCRIPTION OF FACILITIES DESCRIPTION OF SITE OPERATIONS Bulk Storage Facilities Ship Offloading Facilities Road Tanker Off-loading Facilities Road Tanker Loading Facilities MANAGEMENT OF STORAGE TANKS ADDITIONAL IMPORT PIPELINE DESCRIPTION OF PRODUCTS STORED ON SITE DESCRIPTION OF FIRE FIGHTING FACILITIES POPULATION DATA 24 5 POTENTIAL MAJOR HAZARDS INTRODUCTION POOL FIRES TANK FIRES FLASH FIRES VAPOUR CLOUD EXPLOSIONS 28 6 APPROACH TO THE ASSESSMENT TERMINOLOGY HARM CRITERIA 29

16 6.2.1 Thermal Radiation Buncefield Criteria Flash Fire Flammability Limit Fatality Probabilities ASSESSMENT CRITERIA Land Use Planning Around Major Hazard Installations Risk Tolerability Criteria Individual Risk of Fatality Criteria Societal Risk Criteria METHODOLOGY 40 7 RISK ASSESSMENT OF LIQUID FUELS HAZARD IDENTIFICATION Bulk Storage tank Scenarios Buncefield Scenarios Pipework and Pipeline Scenarios Road Tanker Offloading Scenarios Road Tanker Loading Scenarios ESTIMATION OF CONSEQUENCES Pool Fires Buncefield Scenarios ESTIMATION OF INCIDENTS Pool Fire Frequency Calculations Overfill Frequency Calculations Explosion and Flash Fire Frequency Calculations 57 8 RISK ANALYSIS RESULTS FATALITY RISK CALCULATION Location Specific Individual Risk for the site Societal Risk Rate of Harm (Contributors to the Risk) ESCALATION EFFECTS LUP RISK CALCULATION 70 9 RISK ANALYSIS RESULTS FOR ADDITIONAL PIPELINES FATALITY RISK CALCULATION Location Specific Individual Risk for the site Societal Risk Rate of Harm (Contributors to the Risk) ESCALATION EFFECTS OF THE ADDITION OF PIPELINE OPTIONS A AND B LUP RISK CALCULATION NEIGHBOURING MAJOR HAZARDOUS INSTALLATIONS EMERGENCY PLANNING MHI REGULATIONS, SECTION 6 - ON SITE EMERGENCY PLAN 89

17 12 CONCLUSIONS & RECOMMENDATIONS CONCLUSIONS RECOMMENDATIONS 92 ANNEX A ANNEX B ANNEX C ANNEX D ANNEX E ANNEX F ANNEX G ERM CERTIFICATES OF ACCREDITATION MHI REGULATIONS MATERIAL SAFETY SHEETS CONSEQUENCE AND FREQUENCY ANALYSIS EMERGENCY RESPONSE PLAN BURGAN OIL OPERATING AND CONTROL PHILOSOPHY BURGAN OIL COMMITMENT O OPERATING AND CONTROL PHILOSOPHY

18 1 INTRODUCTION 1.1 GENERAL INTRODUCTION A series of major accidents at fuel storage, handling and production facilities have focused worldwide attention on the need to control the design and management of facilities where potential for major accidents exists. In South Africa, the Major Hazard Installation (MHI) Regulations were promulgated on the 16 th January 1998 under Section 43 of the Occupational Health and Safety Act No. 85 of 1993 as amended, to control and manage such activities. The MHI Regulations were revised on 30 th July 2001 and they apply to employers, self-employed persons and users, who have on their premises, either permanently, or temporarily, a major hazard installation or a quantity of a substance which may pose a risk, that could affect the health and safety of employees and the public. A requirement of the MHI Regulations is that a risk assessment needs to be undertaken by an Approved Inspection Authority (AIA), and reviewed at intervals not exceeding five years thereafter. A risk assessment is also required prior to the proposed construction of any major hazard installation. Normally these risk assessments take the form of Quantified Risk Assessments (QRAs). In addition, if there is an incident at an existing site, the facility is also required to revise the MHI Risk Assessment. The MHI Risk Assessment report must be submitted to the Department of Labour and the Local Authorities for review and if necessary, for registration. Environmental Resources Management Southern Africa (Pty) Ltd (hereafter referred to as ERM ) is accredited by SANAS (certificate no. MHI-0012) and is a Department of Labour Approved Inspection Authority (AIA), No. MHI 0008 for Major Hazard Installation Regulations risk assessments. The certification documents are shown in Annex A. As per the accreditation requirements, this report has been reviewed by an ERM Southern Africa Technical Signatory, namely Tim Price. Burgan Oil wishes to construct a fuel receiving, storage and distribution terminal (hereafter referred to as the facility or the site ) on the Eastern Mole Berth in Cape Town Harbour. It is understood that Burgan Oil will operate the terminal on behalf of major oil companies. The site is intended to store petrol and diesel of various grades as well as additives such as ethanol and Bio Fame to supplement the petrol and diesel supply. The site will receive fuel from ships and ethanol and Bio Fame from road tankers. The site will then fill road tankers. In addition the site intends to install an import pipeline to receive product from the Chevron Refinery. This pipeline will either terminate at Tanker Berth 2 or at the Chevron Refinery import manifold at the Chevron Joint Bunkering Services (JBS) fuel terminal. Burgan Oil Cape Terminal identified the proposed terminal as having the potential to affect the health and safety of employees, as well as members of the public beyond the site boundaries, in the event of a major incident. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 1

19 The aim of the project was to undertake a Quantified Major Hazard Installation (MHI) Risk Assessment of the proposed Burgan Oil Cape Town Harbour terminal, with the objective to assess the risk to people off-site via the Land Use Planning (LUP) and Fatality approaches. For this report, ERM have used the current proposed design submitted for the Environmental Impact Assessment (EIA). Any changes to the design of the site will require a new revision to this MHI risk assessment. ERM have assumed that all equipment on the proposed Burgan Oil site will be designed, constructed, operated and maintained to world class standards and will comply with all relevant South African legislation. The latest approaches and some of the lessons arising from the major accident at Buncefield, UK in December 2005 were considered in the assessment. Until the Buncefield explosion of December 2005, significant vapour cloud explosions involving motor spirit were generally not considered credible unless they occurred in heavily congested areas. At Buncefield, a large cloud of vapour was generated when a storage tank was over-filled with petrol over a period of about half an hour. This vapour cloud was ignited and a powerful explosion occurred causing widespread damage and initiating fires in many adjacent tanks. Research is underway to investigate the Buncefield explosion and there is no currently validated simulation tool that is available to predict overpressures in a similar event. Some UK Health and Safety Executive guidance has been published (1) that gives a method for demonstrating the impact of a Buncefield type event. Using the HSE guidance, this Buncefield method has been used within this study. ERM have assumed that the proposed development will comply with world class standards of design, construction and operation. We would also recommend that the site considers implementing all of the recommendations which arose from the incident at the Buncefield Terminal in the United Kingdom in 2005 contained in the UK HSE Process Safety Leadership Group Final Report entitled Safety and Environmental Standards for Fuel Storage Sites. Technical specifications for Burgan Oil Cape Terminal, Cape Town Harbour were gathered during a site visit undertaken by Tim Price of ERM on 21 st November 2013 as well as conversations with Stijn Willem van Zelst. It should be noted that this site investigation was undertaken only for the purpose of gathering information for this quantified risk assessment and not for the purpose of judging the adequacy of the design, operation or maintenance of the site. (1) HSE Annex 17 - Predictive Assessment Line to take for VCE at Bulk HFL Storage Depots, Hazardous Installations Directorate. SPC/Permissioning/11 ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 2

20 1.2 REQUIREMENTS OF THE MHI REGULATIONS The specific requirements for undertaking the QRA are set out in Section 5 of the MHI Regulations and are summarised in Table 1.1 (including the relevant section of this report where the requirement has been satisfied). The current Major Hazard Installations Regulations are attached in Annex B. Table 1.1 MHI Risk Assessment Requirements Requirement Corresponding ERM Report Section (i) a general process description of the major hazard installation Section 4 (ii) a description of the major incidents associated with that type of Sections 5, 7.1 and 7.2. installation and the consequences of such incidents, which shall include potential incidents (iii) an estimation of the probability of a major incident Section 7.3 (iv) a copy of the site emergency plan Annex E (v) an estimation of the total result in case of an explosion or fire Section 7.1 (vi) in the case of toxic release, an estimation of concentration N/A effects of such release (vii) the potential effect of an incident on a major hazard Section 9 installation or part thereof on an adjacent major hazard installation or part thereof (viii) the potential effect of a major incident on any other Section 8 installation, members of the public and residential areas (ix) meteorological tendencies Section 3.2 (x) the suitability of existing emergency procedures for risks Section 11 identified (xi) any requirements laid down in terms of the Environment Section 3.3 Conservation Act 1989 (xii) any organizational measures that may be required N/A ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 3

21 2 RISK ASSESSMENT & MANAGEMENT METHODOLOGY 2.1 DEFINITIONS A hazard is defined by the UK Institution of Chemical Engineers (1) (IChemE) as a physical situation with a potential for human injury, damage to property, damage to the environment or some combination of these. A major hazard is described as an imprecise term for a large scale chemical hazard, especially one which may be realised through an acute event. A major hazard installation is described in the South African Major Hazard Installation Regulations (2) as an installation where any substance is produced, processed, used, handled or stored in such a form and quantity that it has the potential to cause a major incident. A major incident is defined (2) as an occurrence of catastrophic proportions, resulting from the use of plant and machinery, or from activities at a workplace. The process of hazard identification is described by the IChemE (1) as the identification of undesired events followed by an analysis of the mechanisms by which undesired events could occur. Risk assessment is described (2) as a process of collecting, organising, analysing, interpreting, communicating and implementing information in order to identify the probable frequency, magnitude and nature of any major incident which could occur at a major hazard installation and the measures needed to be taken to remove, reduce or control potential causes of such incidents. 2.2 PROCESS OF RISK MANAGEMENT Risk management has become widely used as a technique to aid decisionmaking. Five specific elements are involved: 1. Hazard Identification: to determine the incident scenarios, hazards and hazardous events, their causes and mechanisms. 2. Consequence Analysis: to determine the extent of the consequences of identified hazardous events. 3. Frequency Estimation: to determine the frequency of occurrence of identified hazardous events and the various consequences. 4. Risk Summation: to determine the risk levels. 5. Risk Assessment: to identify if the risk is tolerable/intolerable and to identify risk reduction or mitigation measures and prioritise these using techniques such as risk ranking and cost-benefit analysis. (1) IChemE (1985). Nomenclature for Hazard and Risk Assessment in the Process Industries. (2) Regulation R.692 Occupational Health and Safety Act (85/1993): Major Hazard Installation Regulations. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 4

22 These elements are shown in the flow diagram in Figure 2.1. The elements of the procedure are used both to generate information and as an aid to decisionmaking in managing the risk. For decision-making, the procedure is only taken as far as is necessary to generate the information required or to make the decision. The extent of application of the various elements and degree of quantification employed therefore varies significantly from one situation to another. Figure 2.1 Risk Assessment Process ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 5

23 2.3 HAZARD IDENTIFICATION The first stage in any MHI risk assessment is to identify the potential incidents that could lead to the release of a hazardous material from its normal containment and result in a major accident. This is achieved by a systematic review of the facilities to determine where a release of a hazardous material could occur from various parts of the installation. The major hazards are generally one of three types: flammable, reactive and or toxic. In this study, only flammable hazards are relevant involving loss of containment of diesel, petrol, ethanol and bio Fame. Flammable hazards may manifest as high thermal radiation from fires and overpressures following explosions that may cause direct damage, building collapse, etc. Flammable hazards are present throughout the facility and associated pipelines. Fires may occur if flammable materials are released to the atmosphere and ignition takes place. The possibility of explosions in the instance of over-filling (Buncefield-type incident) has been considered. This study is only concerned with major incident hazards as defined by the scope of the South African Major Hazard Installation Regulations (1). These regulations are concerned only with incidents which involve dangerous substances that give rise to off-site risk as far as the general public and other industries are concerned. 2.4 CONSEQUENCE ANALYSIS Harm Criteria for Consequence Analysis During the analysis it is necessary to define harm criteria (or end points ) for use with the consequence models. In the case of this study, these harm criteria are levels of thermal radiation intensity and where relevant, overpressure (in the case of vapour cloud explosions). The derivation of the harm criteria used in this study is described in Section Consequence Modelling Factors Affecting Consequences There are several factors which affect the consequences of materials released into the environment. These include (but are not limited to): Release quantity or release rate Duration of release (1) Regulation R.692 Occupational Health and Safety Act (85/1993): Major Hazard Installation Regulations. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 6

24 Initial density of the release Source geometry Source elevation Prevailing atmospheric conditions Surrounding terrain Physical and chemical properties of the material released. Such factors will affect the consequence zones for the specific hazardous materials, e.g. the distance at which the level of thermal radiation from a fire or overpressure from an explosion has reduced sufficiently so that it is no longer dangerous. Factors Affecting Fire Hazards When considering large open hydrocarbon fires, the principal hazard is from thermal radiation. The primary concerns are safety of people and potential damage to nearby facilities or equipment. Determination of thermal radiation hazard zones involves the following three steps: Geometric characterisation of the fire, that is, the determination of the burning rate and the physical dimensions of the fire; Characterisation of the radiative properties of the fire, that is, the determination of the average radiative heat flux from the flame surface; and Calculation of radiant intensity at a given location. These, in turn, depend upon the nature of the flammable material, size and type of fire, prevailing atmospheric conditions and the location and orientation of the target/receptor. Consequence Models The hazards described above can be modelled analytically by standard models used for consequence analysis. Many of these models are performed by computer software and ERM has access to a range of such models. The modelling of event consequences is described in Section FREQUENCY OF MAJOR ACCIDENT HAZARDS For each hazard identified, the frequency is assessed. A simple way of defining the frequency of major accident events within a QRA is to use a top down approach. This provides frequencies of the events of interest (fires, explosions, etc.) by reference to historical accident data sources, without considering the causes or development of these events in detail. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 7

25 Alternatively, if more detail is required, a bottom up approach may be used, where the frequency of individual release scenarios is considered. The different outcomes that may result from these releases and the associated frequencies are then developed using techniques such as event tree analysis. A release of hazardous material may be considered for a range of hole sizes, which will depend on the various causes considered. For example, a leak from a pipeline due to corrosion will tend to be small, whereas external impact, say, by a mechanical digger, is likely to produce a much larger hole. ERM has obtained a copy of the Planning Case Assessment Guide (PCAG) developed by the UK Health and Safety Executive (HSE). This enables an estimate of the likelihood of potential hazards following the failure of tanks, vessels, process piping, valves, flanges, etc. to be made. The frequency of the various outcomes (accident scenarios) is then estimated by multiplying the frequency of the release by the probability of the various outcomes. In this study, for flammable releases these outcomes are principally pool fires and flammable vapour clouds of various sizes. 2.6 RISK CALCULATION The individual risk for a specified level of harm is calculated taking the following variables into consideration: The frequency of the hazardous outcome (consequence), e.g. pool fire event The probability that the hazardous outcome (consequence) will reach the location specified (This includes variation of wind direction with consequent change to flame tilt; both downwind and crosswind distances need to be taken into account) Probability of an individual being at the location Probability of escape into shelter by an individual The probability that, given exposure to the hazardous outcome, the person suffers a defined level of harm. The frequency of harm (f h) being present from each hazardous outcome (consequence) event must be calculated and summed to give the maximum individual risk (IR) from all events at one location. IR (max) = f h for all consequences As individual risk is location specific, the above process needs to be repeated for each location considered. The individual risk from other facilities can be summed to give the overall individual risk level from several major hazards. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 8

26 Calculation can be avoided if it is obvious that the event would not be able to affect a location e.g. the specified location is too far away. The frequency of harm will be different for differing weather categories and needs to be calculated for each weather category used. The frequency of harm for a given consequence and weather category is expressed as follows: f h = f e x P w x P d x P exp x P harm Where: f e = frequency of the hazardous outcome (consequence) P w = probability of that weather category P d = probability of the wind blowing in the required direction for event to affect the individual (P d = 0 if event cannot reach a particular location) P exp = probability of exposure P harm = probability that defined level of harm results given that exposure has occurred The probability of the wind blowing in the required direction depends on the angle of entrapment, or the circular sector where a particular hazardous outcome encompasses the specified location. This is a function of the distance from the source, the size, and shape of the hazard footprint. The size and shape of the footprint is determined from the results of the consequence analysis, but gives a complex shape and is correspondingly difficult to calculate the angle of entrapment. These complex shapes are often simplified to regular shapes in order to calculate the angle of entrapment. The frequency of harm for a specific event is the sum of the frequencies of harm for the different weather conditions: f h = f h,weather i all weathers The stability category and wind speed combinations used in the study are discussed in Section 3.2. ERM s proprietary ViewRisk computer software has been used to calculate isorisk contours, which show the geographical distribution of individual risk of harm to people. 2.7 RISK ASSESSMENT The final and most significant step in the process is the assessment of the meaning and significance of the calculated risk levels. Risk assessment is a process by which the results of a risk evaluation are used to make judgements, either through relative risk ranking of risk reduction strategies or through comparison with established risk targets (criteria). Where off-site risk criteria relevant to QRA have been issued (in this case based on criteria used in the UK), it is possible to assess the calculated risk ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 9

27 levels against these criteria. This determines whether the risks are tolerable, broadly acceptable, or if risk reduction/mitigation measures are required to reduce the risk to levels which can be considered to be as low as reasonably practicable (ALARP). The risk events can then be ranked to determine the relative contribution of each to the overall risk level. In general the higher risk events should be examined for possible areas of reduction or mitigation as a first step. Measures that prevent the potential incident from occurring should be considered first, followed by measures that reduce the probability (e.g. reduction in flanges), then measures that may limit the amount released (e.g. remotely operated valves, ROVs) and finally measures that may reduce the potential consequences (e.g. water sprays). The risk assessment will thus enable decisions to be made on whether an investment should be made on particular mitigation measures so that the risk is effectively managed. The residual risk will then be managed by appropriate safety management systems to ensure safe operations, maintenance, good practice, etc. The risk criteria used in this study are presented in Section 6.3. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 10

28 3 ENVIRONMENTAL SITE SETTINGS 3.1 SITE LOCATION The proposed site is intended to be located on Portside Road on the Eastern Mole Berth in the Cape Town Harbour, Western Cape (GPS coordinates in decimal degrees: , ). The site is intended to have two primary, separate operating areas. A storage area is located to the north western end of the berth while the road tanker loading gantry is located further to the south east. A bulk heavy oil storage terminal belonging to Fuel Firing Services is located between the two Burgan Oil site areas. The two areas are linked by aboveground product pipelines The land-use surrounding the site can be summarised as follows: Both Berth 1 and Berth 2 are located on the south western side of the mole and therefore south west of both the storage tanks and the gantry loading facility. At the end of the mole, between Berth 1 and the proposed storage tanks in Bund B, the winch cable storage building is located. Also located on the mole is the FFS Refiners (Pty) Ltd site which is situated between the proposed Burgan Oil storage site and road loading gantry bays. FFS is located on the south west side of the mole with part of the FFS Refiners (Pty) Ltdstorage located between the proposed gantry bay and Berth 2. In addition the site intends to install an import pipeline to receive product from the Chevron Refinery via the Chevron Refinery white oils pipeline. The Burgan Oil pipeline will either terminate at Tanker Berth 2 or at the Chevron Refinery import manifold at the Chevron Joint Bunkering Services (JBS) fuel terminal. Due to the nature of the harbour and mole design, other industrial sites within the harbour are located outside the largest consequence distance and are therefore judged to be not affected in the event of a major incident at the Burgan Oil site. Important surrounding sites: FFS Refiners (Pty) Ltd located adjacent to the site, separated by a service corridor Chevron Joint Bunkering Services (JBS) Fuel Terminal Major transport routes in close proximity to the site: Portside Road is the primary access road to the Eastern Mole Berth. The land-use around the site is shown in Figure 3.1. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 11

29 The following Major Hazard Installations have been identified to be near the site: FFS Refiners (Pty) Ltd located adjacent to the site, separated by a service corridor Chevron Joint Bunkering Services (JBS) Fuel Terminal ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 12

30 Figure 3.1 Aerial Map for Burgan Oil Cape Terminal, Cape Town Harbour, Western Cape

31 3.2 METEOROLOGY Typically, quantitative risk assessments (QRAs) require information about the wind speed, wind direction and stability class. Atmospheric stability is difficult to measure and often varies dramatically over relatively short distances. Atmospheric stability classes need to be defined in the dispersion modelling to facilitate estimates of lateral and vertical dispersion parameters. The preferred stability classification scheme for use in air quality modelling applications is the scheme proposed by Pasquill (1961). The Pasquill Stability Classes are defined by the letters A to F and are described as follows: A. Extremely unstable conditions B. Moderately unstable conditions C. Slightly unstable conditions D. Neutral conditions E. Slightly stable conditions F. Moderately stable conditions. Neutral conditions correspond to a vertical temperature gradient of approximately 1 C per 100 m. The meteorological conditions defining Pasquill stability classes are given in Table 3.1: Table 3.1: Pasquill Stability Classes Surface Wind Day-time Insulation Night-time Insulation Speed (m/s) Strong Moderate Slight >4/8 low cloud 4/8 cloud <2 A A - B B 2 3 A B B C E F 3 5 B B - C C D E 5 6 C C - D D D D >6 C D D D D It is understood that to date no weather stations in South Africa measure both wind speed and stability categories. Since no site-specific weather data were available, meteorological data (i.e. wind and stability data) from the closest weather station, namely Cape Town Airport was sourced from the research report Stability Wind Roses for Southern Africa (1). The average ambient temperature and humidity for Cape Town Harbour were obtained from South African Weather Services. A summary of the data is as follows: (1) Tyson, P.D. et al,'stability Wind Roses for Southern Africa', Department of Geography and Environmental Studies, University of Witwatersrand, ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 14

32 Average ambient temperature is 17 C and average relative humidity 75.5%. ERM selected the following stability classes and wind speed scenarios for modelling purposes: B3 meaning a stability class of B (moderately unstable conditions) where the wind speed is greater than 3 m/s. C8 - meaning a stability class of D (neutral conditions) where the wind speed is greater than 8 m/s. The above weather scenarios give a conservative daytime weather condition. F2 meaning a stability class of F (moderately stable) where the wind speed is less than or equal to 2 m/s. This class is often used by the US Environmental Protection Agency for determining worse case scenarios for vapour cloud dispersion consequence analysis. F2 gives a conservative night time weather condition. Selecting the above categories gives an average and a worst case condition for the risk assessment study. 3.3 REQUIREMENTS OF OTHER ENVIRONMENTAL LEGISLATION EIA Regulations (GNR 543, 544 and 546 of 18th June 2010) promulgated under the National Environmental Management Act No. 107 of 1998, as amended An Environmental impact assessment on the proposed Burgan Oil development is currently being undertaken by ERM. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 15

33 4 DESCRIPTION OF FACILITIES 4.1 DESCRIPTION OF SITE OPERATIONS The proposed Burgan Oil Fuel Terminal is intended to receive AGO (diesel) and ULP (petrol) from transport tanker ships and by pipeline from the Chevron Milnerton refinery. Fuel will be offloaded by two Hard Arms on Eastern Mole Berth 2. Ethanol and Bio Fame are intended to supplement the ULP and AGO at the terminal and are added to the fuels in a set ratio. Ethanol and Bio Fame are delivered to the site by road tanker. Fuel is received from the Chevron refinery by a connection to the current white oils pipeline. The Burgan Oil pipeline connection will be discussed in Section 4.3. The products are pumped from the site storage area through aboveground pipework to the site road tanker loading gantry. Road tankers are then loaded in any of the six loading bays. Road tanker loading occurs during the day and at night. For this MHI report, ERM have assumed that all equipment on the Burgan Oil site will be designed, constructed, operated and maintained to world class standards and will comply with all relevant South African legislation. Burgan Oil is yet to complete detailed designs on the terminal however the site proposed design philosophy is included in Annex F. Burgan Oil has committed to implementing all design features in the aforementioned design philosophy and a letter indicating this intent is shown in Annex G Bulk Storage Facilities The various aboveground storage tanks, along with their products, volumes, height and diameter are shown n in Table 4.1. Table 4.1 Site Storage Tank Details Tank Name Client Name for Product Max Liquid Level (m) Fill rate (m 3 /s) Working Volume (m 3 ) Comments/ References Maximum Volume (m 3 ) Diameter (m) Tank 1 ULP ,000 HH, 9, Tank 2 AGO ,000 HH 9, Tank 3 ULP ,000 HH 9, Tank 4 AGO ,000 HH 9, Tank 5 ULP ,000 HH 9, Tank 6 AGO ,000 HH 9, Tank 7 AGO ,000 HH 14, Tank 8 AGO ,000 HH 14, Tank 9 AGO ,000 HH 14, Tank 10 AGO ,000 HH 14, Tank 11 Ethanol ,700 HH 1, Tank 12 Bio Fame ,700 HH 1, ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 16

34 4.1.2 Ship Offloading Facilities The petrol and diesel storage tanks are filled via pipeline from ships moored at Berth 2): Table 4.3 below summarizes the ship off-loading facility characteristics. The ship will be moored at the berth for 32 hours during off-loading. Table 4.2 Ship Offloading Characteristics Petrol Diesel Size of fuel delivery 30,000 m 3 30,000 m 3 Hard arm size 250 mm 250 mm Line size 300 mm 300 mm Maximum Flowrate 0.26 m 3 /s 0.26 m 3 /s Frequency (Deliveries/year) Road Tanker Off-loading Facilities The ethanol and Bio Fame tanks are filled by means of road tanker off-loading (referred to as bridging ): Table 4.3 below summarizes the road tanker off-loading facilities characteristics. It is understood that a bridging road tanker can remain on site for up to 40 minutes. Table 4.3 Road Tanker Off-loading (Bridging) Characteristics Ethanol Bio Fame Road tanker capacities 30 m 3 30 m 3 Drained area 800 m m 2 Hose size 100 mm 100 mm Pumps 1 ( plus standby) 1 ( plus standby) Line size 100 mm 100 mm Maximum Flowrate m 3 /s m 3 /s Frequency (Deliveries/year) 325 1, Road Tanker Loading Facilities Table 4.4 below summarizes the road tanker loading facilities characteristics. It is assumed that the road tanker can remain on site for up to 40 minutes. ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 17

35 Table 4.4 Road tanker Loading Facility Details Characteristics Ethanol Bio Fame Tanker sizes 42 m 3 42 m 3 Compartment size 6 m 3 6 m 3 Connections per tanker 2 2 Bunded area 3900 m m 2 Hose size 100 mm 100 mm Pumps 5 5 Line size 200 mm 200 mm Average Flowrate in Pipeline to Gantry 0.1 m 3 /s 0.1 m 3 /s Frequency (Deliveries/year) 4,875 11, MANAGEMENT OF STORAGE TANKS For the storage tanks, the storage and movement of fuels at the tank farm will be managed via tank dip reading, and a combination of both manual and automatic tank gauging. All tank management, we have assumed will be undertaken to world class standards and will comply with all relevant South African legislation. Based on proposed designs, all storage tanks on site will be provided with secondary containment and will be able to contain leaks and spills. Table 4.5 shows the proposed bund sizes with the layout of the bunds shown in Figure 4.3. Table 4.5 Burgan Oil Cape Terminal, Cape Town Harbour- Bund sizes ID Containment Name Containment Type Gross Area (m 2 ) Net Area (m 2 ) Wall Height (m) Secondary Containment Bunds and Area (m 2 ) 1 Bund A1 Tank Bund 1, A2, A Bund A2 Tank Bund 1, A1, A Bund A3 Tank Bund 1, A1, A4, A Bund A4 Tank Bund 1, A2, A3, A Bund A5 Tank Bund 1, A3, A Bund A6 Tank Bund 1, A4, A Bund B1 Tank Bund 1, B2, B Bund B2 Tank Bund 1, B1, B3, B Bund B3 Tank Bund 2, B1, B2, B Bund B4 Tank Bund 2, B2, B Bund C1 Tank Bund C Bund C2 Tank Bund C Drained Gantry Drained Area / 2.8 Secondary Containment Wall Height (m) It is understood that all bunds will comply with SANS and that bund sizes and capacities will be appropriate according to the standard (1). (1) South African National Standard Storage and distribution of petroleum products in above ground bulk storage installations, edition ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 18

36 It is assumed that the Burgan Oil Cape Terminal and all equipment on the Burgan Oil site will be designed, constructed, operated and maintained to world class standards and will comply with all relevant South African legislation. ERM would also recommend that the site considers implementing all of the recommendations which arose from the incident at the Buncefield Terminal in the United Kingdom in 2005 contained in the UK HSE Process Safety Leadership Group Final Report entitled Safety and Environmental Standards for Fuel Storage Sites. 4.3 ADDITIONAL IMPORT PIPELINE It is understood that Burgan Oil intends to allow for an import pipeline connected to the main import pipeline servicing the Joint Bunkering Services (JBS) from the Chevron Refinery. The pipeline is understood to be intended to originate in one of two places on the Eastern Mole Berth. These two options will be referred to Option A and Option B and will originate at Tanker Berth 2 connected to the JBS import manifold or connected directly to the Chevron Refinery pipeline import manifold at JBS respectively. The pipeline is understood to run aboveground alongside the Eastern Mole Berth service road and enter the Burgan Oil terminal past the nearby FFS Refiners (Pty) Ltd facility, terminating at the Burgan Oil import fuel manifold. The pipeline is understood to transfer both diesel and petrol to the terminal and is expected to perform transfers not more than twice per month. The operating details of the pipeline are shown in Table 4.6. The layouts of the two additional piping options are shown in Figure 4.1 and Figure 4.2. Table 4.6 Burgan Oil Import Pipeline Operating Specifications Characteristics Diesel Petrol Line Diameter (mm) Operating Pressure (barg) Operating Flowrate (m 3 /h) Days in Use per Month 1 1 ENVIRONMENTAL RESOURCES MANAGEMENT BURGAN OIL MHI FOR EIA V4.0 19