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Risk assessment is increasingly becoming an effective environmental management tool. It is used widely, in a range of sectors and settings, such as the siting and operation of waste disposal sites; the identification and minimization of natural hazards; the management of chemicals in a workplace and the identification and control of diseases. The a...
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Context 1
... same approach is applied to the module on leachate quantity estimation (see Figure 4 ). This fi gure is a form for leachate quantity measurement in the H Iden_Quantity module. ...
Context 2
... are no methods available for leachate quantity estimation in the category of laboratory experimental method(s) and typical values. Therefore, each of these two has a label " None " attached to them as shown in Figure 4 . The H Iden computer tool can store results from more than one meth- od used to measure / estimate leachate quantity of a given landfi ll being assessed. ...
Context 3
... the model is also capable to store values from the same method em- ployed at different times. As shown in Figure 4 , when the button " Workout " is clicked, the model will run a programme embedded in the model to workout maximum, mean / most likely and minimum leachate quantities. These three quantities will be derived from the set of all the values fed into the model from leachate quantifi cation methods applied at various times in a given time period, for instance, around an year. ...
Citations
... They are only referred to where appropriate. This article is one of the articles which deal with other different modules of the total risk assessment methodology [32][33][34][35]. Butt and Oduyemi [33] describe a standalone methodology of concentration assessment of landfill leachate contaminants including toxicity and carcinogenicity aspects. ...
... Butt and Oduyemi [33] describe a standalone methodology of concentration assessment of landfill leachate contaminants including toxicity and carcinogenicity aspects. Butt and Oduyemi [36] presents a holistic baseline study framework for landfill risk assessment process, whereas Butt et al. [34,35] deal with hazard identification and categorization part of landfill risk assessment in which hazards are classified into quality (pollutant and property) hazards, leachate quantity hazard, process, and/or layout hazards and harms. For full details on these publications, the audience of this article is suggested to view the full versions. ...
... This total risk assessment methodology, which is quantitative, comprises a whole set of modules and submodules. These include baseline study (comprising geology, hydrogeology, topography, geography, human influences, etc.) [32]; hazard identification and categorization [34,35]; pollutants migration analysis; hazard indices and acceptable risk levels for noncarcinogens and carcinogens, respectively; exposure assessment with exposure quantifica-tion (being covered in this article); hazards' concentration assessment [33]; and risk estimation. ...
There are generic elements in environmental risk assessments, which are independent of the subject to which risk analysis is applied. Examples of these elements are as follows: baseline study, hazard identification, hazards' concentration assessment, risk quantification, etc. Another important example of such generic elements is exposure assessment, which is required in a risk analysis process for landfill leachate as it would in any other environmental risk issue. Furthermore, computer models are also being developed to assist risk analysis in different fields. However, in the literature review of risk assessment approaches in general and risk analysis regarding landfills in particular, it was discovered that a comprehensive risk assessment methodology addressing all relevant modules and submodules for landfill leachate does not exist. A range of knowledge deficiencies and models' limitations has been uncovered in the literature reviewed to date. One of which is the absence of a holistic exposure assessment framework aided with a corresponding computer model specifically for quantitative risk analysis of landfill leachate. The same is the case for landfill gas and degraded landfill waste (although both are not the focus of this article). From the perspective of landfill leachate, this article attempts to outline an integrated and holistic framework of the exposure assessment accompanied with a computer model, thereby bridging knowledge gaps. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
... In the following sections, the extent to which some important elements in H Iden are absent in risk assessment approaches and computer models is discussed. Furthermore, the elements that should be added to the H Iden rendering it more holistic in order to deliver a more effective risk analysis are also highlighted, though details are described elsewhere (Butt et al ., 2006). The term " holistic " in this study implies an overall structure or framework encompassing all aspects and factors of the H Iden for landfi ll leachate from start to end . ...
... In the H Iden all potential hazards of leachate, either pollutants (such as Mercury, Cadmium) or properties (like Chemical Oxygen Demand (COD), leachate age), are not only identifi ed but also categorized in groups for more comprehensive, effective and categorical risk assessment process. These groups include Quality Hazard (pollutant or property), Quantity Hazard, Process and / or Layout Hazard, and Harms as shown in Figures 2 and 3 and further explained elsewhere (Butt et al ., 2006). From the perspective of landfi ll risk analysis, the defi nition of hazard has been stretched beyond being a substance only. ...
... 3. Identifi cation and categorization of leachate hazards is not divided into these main groups: Leachate Quantity Hazard, Leachate Quality Hazards, Process and/or Layout Hazards, and Harms (See Figure 2 ). 4. Further identifi cation and categorization of leachate quality hazards into the following groups is absent: Pollutant or Property; Toxic, Non-toxic or Both; and Carcinogenic, Non-carcinogenic or Both (See Figure 3 ). 5. Classifi cation of measurement methods of various parameters (such as leachate quantity estimation) into appropriate groups is not employed. Details on this aspect are given elsewhere (Butt et al ., 2006). 6. ...
Risk assessment provides a proactive and logical ground for many decision-making processes. Although the approach of risk assessment nowadays is well established, it remains a relatively new research area, with increasing interest in understanding the principles that underpin the practice. In the review of computer models and literature on environmental risk assessments in general and the risk analysis of waste disposal sites in particular, the authors have determined that a comprehensive risk assessment methodology covering all modules and sub-modules for landfill leachate does not exist. The same fact holds for landfill gas and degraded landfill waste (although these are both beyond the scope of this paper). A range of knowledge deficiencies is identified in the literature. One such deficiency is the development of a strategic procedure for carrying out Hazard Identification and Categorization for risk assessment of landfill leachate, assisted with a corresponding computer model. This study, with reference to the relevant literature, discusses the extent to which the Hazard Identification and Categorization procedure is absent in landfill risk analysis approaches. The elements, which should be added to such a procedure in order to more effectively underpin landfill risk assessments, are also indicated.
The review of literature and computer models described in Part 1 of this paper led the authors to conclude that a quantitative hazard assessment methodology does not exist, in holistic terms, for landfill leachate. Although there are various reports and models addressing different aspects of the methodology, they are not integrated and show different degrees of completion. This part of the paper attempts to bridge some of these knowledge gaps by adapting and researching further the existing research studies to outline a more holistic framework for quantitative hazard assessment. This framework is more categorical, structured and sequential to render the hazard assessment more complete and effective in underpinning quantitative risk analysis. The focus of the paper is to cover the whole range of the hazard assessment in the form of a fundamental framework that draws together all relevant modules and sub-modules under one umbrella, without engaging in much in-depth detail of the modules and sub-modules themselves.
At the present time, risk analysis is an effective management tool used by environmental managers to protect the environment from inevitable anthropogenic activities. There are generic elements in environmental risk assessments, which are independent of the subject to which risk analysis is applied. Examples of these elements are: baseline study, hazard identification, hazards' concentration assessment and risk quantification. Another important example of such generic elements is exposure assessment, which is required in a risk analysis process for landfill leachate as it would in any other environmental risk issue. Furthermore, computer models are also being developed to assist risk analysis in different fields. However, in the review of current computer models and literature, particularly regarding landfills, the authors have found no evidence for the existence of a holistic exposure assessment procedure underpinned with a computational method for landfill leachate. This paper, with reference to the relevant literature and models reviewed, discusses the extent to which exposure assessment is absent in landfill risk assessment approaches. The study also indicates a number of factors and features that should be added to the exposure assessment system in order to render it more strategic, thereby enhancing the quantitative risk analysis.
