Framing Uncertainty in Pipeline Geohazard Assessment for Integrity Management and Iterative Risk Assessment

Author(s):  
Rodney Read ◽  
John Erick Malpartida Moya ◽  
Giancarlo Massucco de la Sota

Pipeline geohazard assessment is becoming recognized by operators and regulators as an increasingly important constituent of overall integrity management and iterative risk assessment of pipelines. An ongoing challenge in assessing the threat posed to a pipeline by various geohazard mechanisms within the B31.8S category of Weather-related and Outside Force is the degree of uncertainty associated with estimates of frequency of occurrence, vulnerability, and loss of containment for individual and cospatial geohazard mechanisms. When combined with threats of other types, such as corrosion and third party damage, estimates of geohazard occurrence frequency and their associated frequency (or probability) of loss of containment may seem imprecise and uncertain. This paper discusses a framework for assessing geohazard susceptibility and the associated uncertainty, and means of incorporating and communicating uncertainty in hazard and risk assessments. Examples are provided from a case study in Perú.

Author(s):  
Moness Rizkalla ◽  
R. S. (Rod) Read

Undertaking a systematic pipeline geohazard assessment may be driven by the design and regulatory permitting needs for proposed new pipelines or as an input to the integrity management of operating pipeline assets. Yet the leading international pipeline codes do not provide explicit direction on undertaking such assessments, rather providing considerable latitude in the guidance to do so which in turn provides several options. The methods for identifying and assessing the potential likelihood and severity of geohazards vary significantly, from purely expert judgment-based approaches relying largely on visual observations of geomorphology to analytically-intensive methods incorporating phenomenological and/or mechanistic models and route, pipeline properties and, where applicable, operational monitoring data. Each of these methods can be used to assess hazard and risk associated with specific geohazards in terms of qualitative, semi-quantitative or quantitative approaches provided that associated underlying assumptions are clearly understood. Some of these methods are better suited to provide a continuous contiguous geohazard risk assessment for a pipeline system while others are better suited for localized site-specific risk assessments. Following a brief review of pipeline codes, this paper provides an overview of the range of pipeline geohazard assessment approaches and explores the “fitness for purpose” strategy that allows for continuing improvement during design stages and into operations.


2017 ◽  
Vol 14 (1) ◽  
Author(s):  
Mariana Campos Fontenelle ◽  
Alexandre de Sousa Fontenelle ◽  
Yago Machado Pereira de Matos ◽  
Fernando Feitosa Monteiro

RESUMO: O presente trabalho tem a proposta de avaliar a eficácia de duas metodologias de avaliação de risco de uma barragem no Nordeste Brasileiro no intervalo de 10 anos, baseando-se na inspeção e no nível de ameaça. Utiliza-se a metodologia Nível de Perigo da Barragem (NPB) para cálculo do nível de ameaça (Fontenelle, 2007) e para o cálculo do risco as metodologias da Companhia de Gestão dos Recursos Hídricos do Ceará (COGERH) e do Conselho Nacional de Recursos Hídricos (CNRH). Observa-se que o crescente número de barragens soma-se a preocupação com a segurança destas. Face a isto, utiliza-se a avaliação de risco como forma de priorizar ações de manutenção e recuperação. O estudo de caso ocorreu na Barragem Malcozinhado, localizada no município de Cascavel, no estado do Ceará. Com base na inspeção, calcula-se o nível de ameaça e o risco, compara-se estes com os resultados de 2006. Assim, observou-se o aumento no nível de ameaça, no entanto, o risco permaneceu, em geral, baixo, semelhante aos resultados de 2006. Este resultado se deve ao fato de que o número de anomalias aumentou, porém trata-se de uma barragem jovem, de pequeno porte e inspecionada regularmente.ABSTRACT: The present study has the proposal of evaluating the effectiveness of two methodologies of risk Assessment of a Brazilian Northeast dam in a range of 10 years, based on the inspection and the level of hazard. The methodology used for calculating the hazard level is the Dam Hazard Level (NPB). In addiction, in order to evaluate the risk is used the methodology of the Water Resources Management Company of Ceará (COGERH) and the methodology of National Resources Council Water (CNRH). The number of dams is increasing with to the concern for their safety. In view of this, risk assessment is used as a tool to prioritizing maintenance and recovery actions. The case study occurred in the Malcozinhado Dam, located in the municipality of Cascavel, in the state of Ceará. Based on the inspection, the level of hazard and risk is calculated, compared to the results for 2006. Thus, the increase in the level of hazard was observed, but the risk remained generally low, similar to 2006 result. This result is due to the fact that the number of anomalies has increased, but it is a young, small and regularly inspected dam.


2011 ◽  
Vol 69 (3) ◽  
pp. 1281-1294 ◽  
Author(s):  
H. B. Wang ◽  
S. R. Wu ◽  
J. S. Shi ◽  
B. Li

2019 ◽  
Vol 263 ◽  
pp. 105351 ◽  
Author(s):  
Chaojun Ouyang ◽  
Zhongwen Wang ◽  
Huicong An ◽  
Xingrong Liu ◽  
Dongpo Wang

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Barbara Kubickova ◽  
Carmel Ramwell ◽  
Klara Hilscherova ◽  
Miriam Naomi Jacobs

AbstractRegulatory hazard and risk assessment of endocrine-active substances currently specifies four modes of action: interference with sex hormone (oestrogen, androgen) pathways, steroidogenesis, and thyroid hormone signalling. This does not encompass the full complexity of the endocrine system and its extended interfaces with environmental pollutants that can potentially disrupt the carefully maintained balance. Here we take the retinoid signalling pathway as a European case study for both, under- and unregulated endocrine pathways and outline the different levels of interference, discuss their adversity, and indicate crosstalk to other signalling pathways. Retinoid compounds already exist in drinking water sources, occur naturally in cyanobacterial blooms and/or enter surface waters via wastewater discharge, where they pose a potential hazard to the environment and human health - a situation that can be expected to worsen due to water shortages induced by climate-change and population growth. We briefly review relevant aspects of current endocrine disruptor (ED) testing for regulatory purposes and then expand upon the needs for inclusion of disruption of retinoid signalling in (ED) regulatory safety assessment contributing to adverse health outcomes that include cognitive function and neurological disease. An overview of developmental effects of retinoid signalling disruption across species highlights critical processes and potential crosstalk with other signalling pathways. A focused weight of evidence-based evaluation of the biologically plausible associations between neurological disorders and altered retinoid signalling highlights the evidence gaps. We show that monitoring only a limited number of anthropogenic priority chemicals in water is insufficient to address the environmental risks of retinoid signalling disruption. To comprehensively assess impacts on the endpoints, processes, and pathways of the endocrine system that are most vulnerable to chemical interference we need further investigation of the true mixture composition in environmental matrices. On a weight of evidence-basis this information can then be integrated into a reliable, inclusive, quantitative approach that ultimately accommodates all the critical pathways. By focusing on the retinoid signalling pathway, we intend to improve the scope and relevance of an integrated approach for the risk assessment of endocrine disruptors.


2011 ◽  
Vol 9 (1) ◽  
pp. 10-26 ◽  
Author(s):  
Margaret Donald ◽  
Kerrie Mengersen ◽  
Simon Toze ◽  
Jatinder P.S. Sidhu ◽  
Angus Cook

Modern statistical models and computational methods can now incorporate uncertainty of the parameters used in Quantitative Microbial Risk Assessments (QMRA). Many QMRAs use Monte Carlo methods, but work from fixed estimates for means, variances and other parameters. We illustrate the ease of estimating all parameters contemporaneously with the risk assessment, incorporating all the parameter uncertainty arising from the experiments from which these parameters are estimated. A Bayesian approach is adopted, using Markov Chain Monte Carlo Gibbs sampling (MCMC) via the freely available software, WinBUGS. The method and its ease of implementation are illustrated by a case study that involves incorporating three disparate datasets into an MCMC framework. The probabilities of infection when the uncertainty associated with parameter estimation is incorporated into a QMRA are shown to be considerably more variable over various dose ranges than the analogous probabilities obtained when constants from the literature are simply ‘plugged’ in as is done in most QMRAs. Neglecting these sources of uncertainty may lead to erroneous decisions for public health and risk management.


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