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Risk assessment of atmospheric emissions from gold mine tailings on the Witwatersrand

  • Authors: Ojelede, Matthew Ehigiator
  • Date: 2012-08-15
  • Subjects: Risk assessment , Air pollution , Mine drainage - Environmental aspects , Slimes (Mining) - Environmental aspects , Tailing dams - Environmental aspects , Witwatersrand (South Africa)
  • Type: Thesis
  • Identifier: uj:9362 , http://hdl.handle.net/10210/5800
  • Description: D.Phil. , Over a century gold exploration and extraction on the central Witwatersrand has left a legacy of mine residue deposits. Although there have been numerous complaints and claims of health effects associated with dust from these residue deposits, mostly these have been dismissed as mere nuisance. This study hypothesized that gold mine tailings on the Witwatersrand pose significant health risks to the nearby communities due to respirable airborne tailings material. Preliminary review of information on the tailings led to the insight that tailings source material and atmospheric properties at receptor sites are poorly characterized from the point of view of particle size-mass distributions. For years, routine monitoring of emissions from tailings storage facilities has been limited to sampling of dust fallout (settlable particles ≥ 30 μm). A suite of fifty four source samples (thirty-six slime, six newer slime and twelve sand) were collected from tailings storage facilities along the mining corridor covering deposits in the Carltonville area through to Springs. Size class characterization of source material was performed in the diameter range 0.05 μm to 900 μm using a Malvern® MS-14 Particle Analyser with 64 channels, from which the respirable (dp< 5 μm) and thoracic (dp < 10 μm) components were measured. Secondly, source materials were sieved (using a sieving cloth) in dp < 5 and < 10 μm fractions and the data derived was used in validating the size class results from the Malvern® MS-14 Particle Analyser before subjecting the samples to chemical analyses (elemental, mineralogical and radioactivity). Two years of continuous dust fall samples were collected in two different residential areas close to selected tailings storage facilities and subjected to similar size class characterization with the Malvern® MS-14 Particle Analyser. Further, continuous size-mass characterization of airborne aerosols was conducted in two different locations in the vicinity of tailings storage facilities with the Grimm® aerosol particle counter, in the diameter range 0.25 μm to 32 μm. The Grimm® aerosol particle counter was collocated with the MicroVol® PM10 filter sampler ambient monitor. The risk zones around selected tailings storage facilities were established by conducting dispersion modeling with American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD). The spatial evolution of tailings storage facilities and built-up areas is assessed using multiple aerial photographic images, covering four periods from 1952 to 2008. Overall, detailed spatial analysis was conducted and human inhabitants are now at greater risk than before. We have quantified the number of inhabitants living within the high-risk zone surrounding selected tailings storage facilities. The combined areas occupied by tailings storage facilities have increased from ~4 km2 (1952) to 10 km2 (2002); and residential areas ~4 km2 (1952) to 27 km2 (2002) within a buffer of 2 km. Population grew between 1952 and 2002 by a factor x29 at Crown Gold Recoveries; x43 at Durban Roodepoort Deep (from 1976); and x25 at East Rand Proprietary Mines.
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An application of risk based design in open pit mine planning

  • Authors: Brits, Leilani
  • Date: 2014-05-26
  • Subjects: Strip mining - Planning , Strip mining - Design and construction , Mining engineering , Risk assessment
  • Type: Thesis
  • Identifier: http://ujcontent.uj.ac.za8080/10210/388561 , uj:11216 , http://hdl.handle.net/10210/10809
  • Description: M.Ing. (Engineering Management) , The design of the optimum open pit slope angle is one of the major challenges during open pit mine planning, as it implies attaining the ideal balance between utilizing the maximum slope angle whilst achieving acceptable stability and safety standards as indicated by the mine. The aim of open pit mines should thus be to seek the steepest possible slope angle without compromising the safety of the personnel, equipment or ore reserves, utilizing both stability analyses as well as risk assessments. The typical open pit mine plan aims to achieve an acceptable balance between operational risks and geotechnical design considerations by analysing factors such as the slope stability design, the rock mass properties and existing structural geological conditions. These factors are used as inputs towards an optimum slope angle design which will be used in the final pit design and aims to provide maximum economic viability to the mine. The risk analysis methodology aims to improve traditional slope design methods and is used to evaluate risks and failure consequences in terms of economic impacts. The economic impact analysis is a useful method in comparing the performance of various mine plans and slope designs. The risk analysis methodology thus provides a valuable indication of optimum slope design configurations and as such can be a great asset to the mine design process. This research paper aims to identify the key risks used as input to an open-pit mine plan in a feasibility stage and to define an approach to minimize these risks in order to achieve maximum economic benefit. The effectiveness of this approach will be evaluated by means of a case study which will attempt to achieve an optimum balance between value and risk, and to compare the magnitude of the economic impact of an individual risk with the probability of occurrence of said risk. The case study will utilise a risk map in order to define years with higher economic impacts as well as defining critical pit areas causing these risks, so as to identify areas requiring further investigation which will assist the mine in evaluating mitigation strategies in order to reduce overall risk.
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Saamgestelde portefeuljes : 'n kritiese risikometings- en evalueringsmodel

  • Authors: Goosen, Eugene
  • Date: 2012-08-28
  • Subjects: Risk assessment , Pricing , Portfolio management
  • Type: Thesis
  • Identifier: uj:3352 , http://hdl.handle.net/10210/6752
  • Description: M.Comm. , ffntroduction Measuring and evaluating risks are essential in a dynamic derivative market to minimize risks. The management of risks in the derivative market is complex due to the non-linear properties of option pricing Method of study The a first step of the study analyzed the "greek" derivatives of a single option contract (e.g. delta, gamma, vega, theta). The next step was to combine and analyze the derivatives of various option contracts. The study pointed out that the risk profile can be amended by combining option contracts. A risk measurement and evaluation model was constructed by creating a table that will simulate option prices at different time horizons and at different market prices. The model will also simulate all the derivatives of options in a table form at different time horizons and at different market prices. The model finally used the tables to reflect the results graphically. Findings The last section of the study was devoted to scenario simulation to identify risks. Firstly the management of the delta was analyzed, and the use of the gamma to identify delta sensitivity was illustrated. The management of the vega was addressed next. The study showed that a combination of options can minimize the risk of vega. The effect of theta or the time value of a option was illustrated and linked to both gamma and vega. The study demonstrated that the results of volatile movements in the market can be simulated by combining the derivatives of options (e.g. add the deltas of options together), and to stress test the strategy. "What if' scenarios can be simulated to illustrate the effect on a current position combined with some amendments.
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A review of research on lightning protection for photovoltaic systems

An investigation into business continuity risks and related business continuity plan

  • Authors: Nel, Izette
  • Date: 2012-06-07
  • Subjects: Risk , Risk management , Risk assessment , Crisis management , Business planning
  • Type: Mini-Dissertation
  • Identifier: uj:8715 , http://hdl.handle.net/10210/5067
  • Description: M.Comm. , To prevent the interruption of an organization’s daily operations in the event of a catastrophe, organizations must reconsider the importance of creating awareness and being prepared for the unexpected. The importance of business continuity for the survival of any organization during a crisis or disaster has become a prominent factor within the modern organization. Organizations must fully understand the importance of this factor and the impact it could have on the organization. Adequate and effective actions and procedures should be in place to address the organization’s business continuity risks. The study investigated the different business continuity risks that an organization faces in its internal and external environment and the concept and principles of an effective business continuity plan to address and manage these risks. This was done by way of a comprehensive literature study on business continuity factors as well as an empirical study of established business continuity practices at the audit clients of the four largest audit firms. The study found that there are various categories of business continuity risks that are applicable to the modern organization, but although the majority of organizations are aware of the risks that they are faced with not all organizations fully understand the impact of these risks on the organization and therefore not all organizations have effective and adequate business continuity plans in place to address and manage these risks. Organizations are not placing focus on the establishment of a business continuity culture within the organization that supports its business continuity philosophy and the success of its business continuity actions and procedures. It was evident that there is still room for improvement in the way organizations currently address their business continuity risks.
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Controlling risk in a town house development : a case study

  • Authors: Gordon-Watt, Matthew
  • Date: 2011-12-06
  • Subjects: Loss control , Risk management , Risk assessment , Project management , Housing development , Real estate development
  • Type: Thesis
  • Identifier: uj:1857 , http://hdl.handle.net/10210/4214
  • Description: M.Ing. , As the title of the dissertation implies, 'control' and 'risk' are the core issues regarding the dissertation. The approach by which a property development company manages these two issues are the focal points. The primary research objective was to draw conclusions from feedback obtained via a property developer and compare the findings to its literature counterpart. Expanding on the primary objective one aimed to determine commonalties and differences (case study and literature) and derive logical explanations for those differences. The second research objective was a by-product from the first. That being if the property developer is controlling his risk in the best manner possible given the inherent restrictions, in other words is the system efficient. It was evident that control measures and ways to identify and manage risk were put in place by the developer. Most of the literature theory corresponds with that of the property developer. Elements of risk were noted via analysis of the results. One way of increasing the efficiency of the system would be to increase the focus/resources in the evaluation/planning phase. In turn by improving the control mechanisms it may be possible to improve the systems efficiency. Risk can not be eliminated in its entirety - it is part and parcel of any business, particularly that of property development. Risk and control are therefore critical elements in any business. Understanding the core issues surrounding those elements can only prove beneficial to a company's success. Furthermore, the dissertation raised important issues that may be addressed in future research. Issues that may be followed up on in future research include and are not limited to the following: • Analysis of control and risk management' methods on a broader scale, in terms of a larger survey population. • Investigate and analyze the efficiency of a property development company/companies. • Expand on various risk issues: - return on investment, the market, project site, the project, the process, the organization and contingency. • Expand on various control measures: - tools (charts, schedules etc.), communication.
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Risk management approach for the life cycle of a lined tailings dam

  • Authors: Otto, Hendrik Johannes Hertzog
  • Date: 2012-06-04
  • Subjects: Tailings dams , Risk management , Risk assessment , Fault trees , Industrial safety , Mine safety
  • Type: Thesis
  • Identifier: uj:2357 , http://hdl.handle.net/10210/4812
  • Description: M. Ing. , Managing the risks to life and limb and to the environment due to potential accidents and structural failures during the lifecycle phases of a TD is a complex, intricate and dynamic process, because of the sheer number of hazards that are involved. Fault and event trees enable one to systematically identify these hazards within the context of their intricate relationships. An internationally accepted qualitative scale enables one to assign probabilities in terms of engineering judgement to the sub-causes in the fault trees and the probabilities of the top faults to be calculated. Mine and industry accident statistics enable one to assign relevant frequencies to the subtended event trees and to determine the resulting probabilities of fatal injury or environmental damage. An internationally accepted relationship between lifetime probability of failure causing death and the potential number of fatalities enables one to determine whether the resulting probability of fatal injury is acceptable. If such resulting probability of fatal injury is not acceptable, the biggest contributing subcauses in the underlying fault tree can be identified and mitigating measures considered on an optimal cost benefit basis. The fault trees for the different life cycle phases of the TD also enable one to take cognisance of the dynamic changes in the frequencies of the sub-causes in the various phases and how the risk management focus may change over the life of a TD although the overall threat may not necessarily vary very much. During investigation of the causative modes for personal injury due to mine accidents/hazards at or on the TD it was found that the probabilities associated with fatal injury during the life cycle phases considered were acceptable. The sensitivity of the factors was however investigated further to provide confidence, and event and consequence trees were developed for TD road accidents which were identified as having the highest probabilities of occurrence. The most efficient risk management intervention measure evaluated was found to be increasing compliance with the mine’s road traffic safety regulations. Investigation of the causative modes for personal injury due to structural failure of the TD determined that the probabilities associated with fatal injury were acceptable and no risk mitigation measures were thus required. The causative modes for environmental damage due to mine accidents/hazards were examined next and the probabilities associated with environmental damage were found to be unacceptably high for the life cycle phases considered. Risk management intervention 57 measures were thus required to lower the associated risks to acceptable levels based on relevant and realistic environmental protection guidelines. No mitigation measures were developed as part of the study. Causative modes for environmental damage due to structural failure of the TD were investigated last. The probabilities associated with environmental damage during the life cycle phases considered were also found to be unacceptably high. Risk mitigation measures were thus required but none were developed as part of the study. Fault and event tree methodology as employed in this study can thus be used as valuable supporting instruments for investigating the causative failure modes of a complex system, the identification of potential risk mitigation measures, and for evaluation of the effectiveness of the proposed risk management measures.
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The quantification of information security risk using fuzzy logic and Monte Carlo simulation.

  • Authors: Vorster, Anita
  • Date: 2008-06-04T11:27:02Z
  • Subjects: Risk assessment , Monte Carlo method , Fuzzy logic , Computer security , Information technology risk assessment
  • Type: Thesis
  • Identifier: uj:8851 , http://hdl.handle.net/10210/527
  • Description: The quantification of information security risks is currently highly subjective. Values for information such as impact and probability, which are estimated during risk analysis, are mostly estimated by people or experts internal or external to the organization. Because the estimation of these values is done by people, all with different backgrounds and personalities, the values are exposed to subjectivity. The chance of any two people estimating the same value for risk analysis information is rare. There will always be a degree of uncertainty and imprecision in the values estimated. It is therefore during the data-gathering phase of risk analysis that the problem of subjectivity lies. To address the problem of subjectivity, techniques that mathematically deal with and present uncertainty and imprecision are used to estimate values for probability and impact. During this research a model for the objective estimation of probability was developed. The model uses mostly input values that are entirely objective, but also a small number of subjective input values. It is in these subjective input values that fuzzy logic and Monte Carlo simulation come into play. Fuzzy logic takes a qualitative subjective value and gives it an objective value, and Monte Carlo simulation complements fuzzy logic by giving a cumulative distribution function to the uncertain, imprecise input variable. In this way subjectivity is dealt with and the result of the model is a probability value that is estimated objectively. The same model that was used for the objective estimation of probability was used to estimate impact objectively. The end result of the research is the combination of the models to use the objective impact and probability values in a formula that calculates risk. The risk factors are then calculated objectively. A prototype was developed as proof that the process of objective information security risk quantification can be implemented in practice. , Prof. L. Labuschagne
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Developing a framework for secure use of portable storage devices in a corporate environment

  • Authors: Molotsi, Kegomoditswe Noreen
  • Date: 2015
  • Subjects: Mobile computing - Security measures , Smartphones - Security measures , Operating systems (Computers) - Security measures , Wireless communication systems - Security measures , Risk assessment
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/58790 , uj:16491
  • Description: Abstract: Portable Storage Devices (PSDs), also referred to as USB Mass Storage (UMS) devices in this study, are affordable, convenient, practical, and have the ability to interface easily with a number of operating systems and various hardware systems. UMS devices are found among virtually any person in the workplace today. However, UMS devices hold significant security risks, which are often overlooked. These risks arise mainly due to their compact size, storage capacity or the fact that UMS technology is integrated into smartphones, cameras, music players, to name the most significant ones. Considering that UMS technology is incorporated into devices that employees need daily to perform their work, such as smartphones, it is not a feasible option to ban UMS technology from the workplace. Nonetheless, without a guiding framework, UMS devices pose security risks to both organisations and individual users. This study reports on research conducted at a research institution in South Africa to evaluate an employee’s understanding of the security risks to the organisation and to them in person. From the results derived from the research conducted, a conceptual framework model was developed to address the security concerns associated with UMS devices. , M.Sc. (Informatics)
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A proposed sector wide risk model based on enterprise wide risk management

  • Authors: Buhr, Richard Otto
  • Date: 2012-06-04
  • Subjects: Risk management , Risk assessment , Crisis management
  • Type: Thesis
  • Identifier: uj:2331 , http://hdl.handle.net/10210/4789
  • Description: D.Ing. , For executive management to guide an enterprise, strategic planning is essential. Using Enterprise Wide Risk Management (EWRM) as an input to Scenario Analysis (SA) for Strategic Planning (SP) allows for improved accuracy over conventional methods. This would allow for greater realism from the executive management perspective of possible outcomes in scenario modelling by providing a solid quantitative base founded on real operational information. Emerging regulatory legislation for corporates also require quantitative risk management in the enterprise for reporting and rating purposes, providing a wealth of information for scenario modelling purposes. From the outset this research focuses on the industrial sectors in South Africa, though the model could be applied to any industry sector internationally. The core of any industrial enterprise is made up of the Operational Support Systems (OSS) that provide the hardware and software infrastructure to operate the business. The smooth operation and efficient handling of any unforeseen events in the OSS impacts the very survival of the en- terprise in a highly competitive environment. The development of an OSS risk management (RM) strategy to provide an efficient and effective way to recognise, classify and mitigate the risks involved in OSS is thus crucial to any enterprise that seeks to remain competitive. To implement this RM strategy and provide information regarding likely loss events, a quantitative risk model is required to simulate different scenarios. This research investigates the development of a Sector Wide Risk Model (SWRM) to simulate stress events in an industry sector and their impact on sector members.
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Risk evaluation in project management implementation : the case of infrastructural development projects in Transnet

  • Authors: Dludhlu, Nokuthula Isabella
  • Date: 2016
  • Subjects: Project management , Risk assessment , Transnet (Firm : South Africa)
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/225278 , uj:22750
  • Description: Abstract: The project management environment is exposed to risk. When an organization identifies a gap or opportunity it will decide to embark on an endeavor to address the need. A project has specific objectives to fulfil. In the process of implementing a project, there may be events that should they occur will threaten the successful completion the project. These events are what pose a risk to a project and if realized, will have an impact on a project. A project management process should enable the identification of potential risks to the project so that actions to minimize the risk impact and/or to mitigate can be developed. Once identified, the probability that the risk event will occur can be determined, and subsequently the extent of its impact can be assessed. A risk management process enables the organization to be aware of its exposure to risk. It also allows the organization to deal with the anticipated risk proactively. The risk management process evaluates the potential risks that could be realized in a project. Risk management should be built into the organization’s process of project implementation. Project success is somewhat dependent on the ability of the project management process practiced by the organization. A project management process should be able to focus on all aspects contributing to the achievement of project objectives. The elements often used by organizations to measure project performance are cost, time, and quality. The project management body of knowledge (PMBOK) gives definitions of these elements. The cost element refers to the completion of the project within the set budget. The project cost involves determining and allocating of funds towards acquisition of the resources required for the execution of the project. The time element refers to the timely completion of the project. The project duration is determined by defining the activities required to complete the project scope. The quality element refers to delivering the project to meet the specified performance requirements. Quality compliance is ensured through identifying the specifications that apply to the project, and constantly evaluating the performance of the completed work within a project. A risk management process identified in literature is described by Farias et. al. 2003, is divided into the evaluate process and control process. Three factors which potentially impact on risks that could be anticipated in infrastructural development projects that are a focus of this research are human, organizational and technological. The objective of the study is to identify the risk factors impacting infrastructural development projects and to propose the mitigating factors to reduce these risks. Chapter 1 gives the background information of the study and also describes the problem statement, research objectives and the research questions. Chapter 2 provides the literature review studied in order to understand the broad subject matter relevant to the study. Chapter 3 presents risk management models identified in literature and a deduced integrated framework. Chapter 4 describes the research methodology undertaken to carry out the study, whereby a survey was used to gather information and data that pertains to infrastructural development projects. Chapter 5 presents the research findings. A statistical analysis of the findings will produce conclusions and recommendations presented in Chapter 6. , M.Ing. (Engineering Management)
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Risk assessment in infrastructural projects

  • Authors: Marowa, Y.N. , Muyengwa, G.
  • Date: 2015-06-08
  • Subjects: Infrastructural projects , Risk assessment
  • Type: Article
  • Identifier: uj:5105 , ISBN 978-1-77592-111-0 , http://hdl.handle.net/10210/13926
  • Description: Infrastructural projects presents opportunities of economic growth and social development. These type of projects are normally undertaken by governments and include projects like building major roads, dams, power stations, railway lines, ports and airports. These projects, when completed supports varied economic activities including much needed employment creation. The life cycle of infrastructural projects is characterized by the involvement of various stakeholders who participate at different stages of the project. Projects of this magnitude are associated with diverse risks that include under management, under-financing, cost-overruns, delays, failed procurement, poor scheduling, inadequate designs, human risks, organizational risks and technological risks. The purpose of this research paper is to assess risks that were faced by Company A that is involved with power generation infrastructural projects. In this paper we report on the findings of risks that impacted negatively on the timeously delivery of an infrastructural project. This paper focusses on assessing risks that are found in infrastructural projects. A case study was carried out on Company A. The case study involved a survey, were 35 valid responses were received and six senior project managers were interviewed. The research found that planning, execution and delivery of infrastructural projects is very complex. Some of the risks that were noticed in Company A were poor designs, lack of skilled manpower and poorly defined roles between contractors and operators. Undercapitalization was found to be the major risk. To enhance the successful offering of projects companies must have a proactive approach. This paper builds up on the body of knowledge of risks found in infrastructural projects. To project practitioners the paper highlights the importance of project budgeting, scope creep, and soft issues on human factors such as cohesion among team members.
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Regional scale risk assessment methodology using the relative risk model as a management tool for aquatic ecosystems in South Africa

  • Authors: O’Brien, Gordon Craig
  • Date: 2012-11-05
  • Subjects: Risk assessment , Risk management , Ecological risk assessment , Aquatic ecology , Ecosystem management
  • Type: Thesis
  • Identifier: uj:7348 , http://hdl.handle.net/10210/8096
  • Description: Ph.D. (Zoology) , Due to the excessive utilisation of the ecological services of surface aquatic ecosystems in South Africa, the integrity state of these systems continues to decline resulting in the loss of key ecosystem services. This trend suggests that the national requirements to maintain a sustainable balance between the use and protection of these systems are not being met. In an attempt to address this status quo, all stakeholders of these systems need to become more closely engaged in the social and institutional decision making processes to manage these systems. Management plans need to be integrated and take a wide range of conservation and use objectives for specific ecosystems into account. Furthermore, approaches need to allow for the assessment of multiple stressors that have synergistic effects, while the unique characteristics of the ecosystem taken into consideration. Risk assessments entail assigning magnitudes and probabilities to hazards or anthropogenic activities or natural catastrophes that have adverse effects m ecosystems. In these assessments the existence of a hazard and the related uncertainty of its effects results in the formulation of risk. An Ecological Risk Assessment is a structured approach that describes, explains and organises scientific facts, laws and relationships, thereby providing a sound basis to develop sufficient protection measures for the environment, which facilitates the development of utilisation strategies for the environment. A Regional Scale Risk assessment using the Relative Risk Model (RRM) is a form of Ecological Risk Assessment that is carried out on a spatial scale where considerations of multiple sources of multiple stressors affecting multiple endpoints are allowed. The use of the RRM also allows for the characteristics of the landscape that may affect the risk estimate to be considered. This study is based on a research hypothesis that the RRM is a suitable water resources management tool that can address the risk assessment of multiple stressors in South African freshwater environments. To test this hypothesis this study aims to contextualise the RRM methodology within the current water resources management practices in South Africa and demonstrate the applicability of RRM within the South African water resources management framework. The applicability of the RRM will be tested using two case study regions. The case studies are the Elands River and its associated ecosystems in the upper Crocodile River catchment in Mpumalanga and the entire catchment of the Umvoti River in KwaZulu-Natal
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Risks associated with South African energy pipelines

  • Authors: Van den Berg, Hugo
  • Date: 2012-06-06
  • Subjects: Energy pipelines , Pipelines , Business logistics , Supply chain management , Risk assessment
  • Type: Thesis
  • Identifier: uj:2488 , http://hdl.handle.net/10210/4942
  • Description: M.Comm. , The demand for products which are distributed through pipelines has increased worldwide over the last decade. These increases in demand have irrevocably impacted upon top management’s perceptions of risks associated with energy pipeline supply chains. Even in South Africa, the increase in demand for products such as diesel, jet fuel and petrol, which are supplied through the energy pipeline supply chains have increased the risks associated with energy pipeline supply chains. This study explores the different risks associated with South African energy pipelines, and investigates whether these risks can have an influence on the business as well as the physical environment of the energy pipeline supply chains. A literature study was conducted and three energy pipeline supply organisations surveyed to determine what their specific viewpoints were regarding the risks faced by the South African energy pipeline supply chains.
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