Literature review of baseline study for risk analysis - the landfill leachate case

There is growing awareness and public concern about environmental impacts of waste management and disposal. Environmental policy instruments have been strengthened and associated governmental programmes have increased in recent years, resulting in high level strategies for waste management. Risk assessment is now an essential tool in the prioritisation of environmental and human health protection. However, regulators need to compare the full range of risks on a sound and consistent basis. Comparing risks from such diverse sources poses a significant challenge, and traditional hazard and risk assessments are no longer sufficient. Consideration now needs to be given to a much wider range of factors if risk assessment is to be used as an aid to more integrated decision-making process. For this purpose, baseline study - the foundation of risk assessment - can play a crucial role. To date limited research has been conducted on the need, parameters, requirements, and constituents of baseline study particularly in the context of how, why, and what information is to be collated in order to render risk assessments more appropriately integrated and complete. To establish the 'state-of-the-art' of baseline study, this paper comprehensively reviews the literature regarding environmental risk assessment in general terms, and then proceeds to review work that is specifically related to landfills and landfill leachate, thereby identifying knowledge gaps and shortfall areas. This review concludes that a holistic baseline study procedure for waste disposal sites, which risk assessors could use for carrying out risk analyses specifically for landfill leachate, does not as yet exist.

A systematic review of risk assessment tools for contaminated sites - Current perspectives and future prospects

Health and safety hazards associated with the redevelopment of contaminated sites can be complex and pose considerable risks. A systematic literature review was conducted on risk assessment tools for contaminated sites. These tools have been identified from searching through leading academic databases and other professional sources. For each of the identified tools the relevant risk assessment stages, harm type, hazard category, receptor type and pathways are reported. Findings reveal that despite growing interest in the development of risk assessment tools, there are persistent knowledge gaps identified in this study, which serve as a basis for future research direction to where more advanced practical tools could be invented. For instance, it is evidenced there is a shortfall in practical tools available to contaminated site assessors conducting investigations at the preliminary risk assessment stage. Addressing this opening can benefit the planning process, coordinated between relevant stakeholders and, moreover, reduce uncertainty in the decision-making of contaminated site developers.

A holistic approach to Concentration Assessment of hazards in the risk assessment of landfill leachate

Risk assessment is a new research area. The risk assessment research area deals with a wide range of issues other than landfills. Examples of these issues are Radiation, Food Industry, Ecology, Epidemiology, etc. The authors have found that there are generic elements in risk assessment and these elements are independent of the subject areas mentioned above. An important example of these generic elements is the Concentration Assessment of hazards and is equally important from the perspective of landfill risk assessment. Furthermore, in the literature review of landfill risk assessment approaches, no evidence has been discovered of a holistic risk assessment methodology for landfill gas, leachate, or degraded landfill waste. A range of knowledge deficiencies has been found in the literature reviewed to date. One of these deficiencies in knowledge is the lack of a holistic procedure for carrying out Concentration Assessment. From the perspective of landfill leachate, this paper discusses the extent to which the Concentration Assessment of hazards is absent in landfill risk assessment approaches described in the literature reviewed to date, and the elements that should be added to the procedure of the Concentration Assessment in order to enhance the process of risk assessment. The paper also briefly outlines a holistic procedure for the Concentration Assessment and a corresponding computer model for the risk assessment of landfill leachate.

Baseline study and risk analysis of landfill leachate - Current state-of-the-science of computer aided approaches

For the successful completion of a risk analysis process, its foundation (i.e. a baseline study) has to be well established. For this purpose, a baseline study needs to be more integrated than ever, particularly when environmental legislation is increasingly becoming stringent and integrated. This research investigates and concludes that no clear evidence of computer models for baseline study has been found in a whole-system and integrated format, which risk assessors could readily and effectively use to underpin risk analyses holistically and yet specifically for landfill leachate. This is established on the basis of investigation of software packages that are particularly closely related to landfills. Holistic baseline study is also defined along with its implications and in the context of risk assessment of landfill leachate. The study also indicates a number of factors and features that need to be added to baseline study in order to render it more integrated thereby enhancing risk analyses for landfill leachate.

Framework for preliminary risk assessment of brownfield sites

The complexity of hazards, risk and environmental legislation surrounding the reuse of brownfield sites necessitates a preliminary risk assessment prior to their redevelopment. Most prevailing efforts have been targeted at indepth site investigations, which are often costly, time-consuming, and may not be required at the early stages of a site development. However, there is a collective absence of knowledge, methods and computer models that can present a complete framework to carry out a preliminary risk assessment that is simpler, quicker and sufficient, not only for risk assessor but also effectively communicative for a diverse range of stakeholders with or without risk assessment expertise. Therefore, this study aims to bridge this gap by designing and creating a framework, by not only identifying hazards but also exposing the degree of presence. Sixty-five potential hazards have been identified from a comprehensive literature review. A questionnaire survey was then shared with brownfield site experts (n = 76) that asked then to rank the priority of the potential hazards. Kendall's W test and Kruskal-Wallis H test were subsequently conducted to determine the level of agreement among the respondents. Mean weightings were calculated by using the Voting Analytic Hierarchy Process (VAHP) to prioritize the potential hazards from 'more likely' to 'least likely'. Based on this information, the framework has been developed. It is anticipated that the framework can assist professionals to conduct a preliminary assessment of brownfield sites, which enables them to gain informative and rapid guidance on any potential liabilities or risks related to a site's suitability for acquisition or redevelopment. In this context, the framework outlines a systematic structure to collect appropriate data and information in the three main categories which are sources, pathways and receptors.

Development of a conceptual framework of holistic risk assessment - Landfill as a particular type of contaminated land

Landfills can be regarded as a particular type of contaminated land that has a potential to directly and indirectly pollute all of the four main spheres of the environment which are the lithosphere, atmosphere, hydrosphere and eventually adversely impact the biosphere. Therefore, environmental risk assessment of a landfill has to be more integrated and holistic by virtue of its nature of being a multidimensional pollutant source. Despite this, although various risk assessment approaches have been adopted for landfill waste disposal sites, there are still wide-ranging knowledge gaps and limitations which need to be addressed. One important knowledge gap and limitation of current risk assessment approaches is the inability to fully identify, categorise and aggregate all individual risks from all combinations of hazards, pathways and targets/receptors (e.g. water, air, soil and biota) in connection to a certain landfill leachate and yet at any stage of the landfill cycle. So such an approach is required that could not only integrate all possible characteristics of varying scenarios but also contain the ability to establish an overall risk picture, irrespective of the lifecycle stage of the landfill (e.g. planning stage/pre-operation, in-operation or post-operation/closed). One such approach to address the wide-breadth of landfill impact risks is by developing a more holistic risk assessment methodology, whose conceptual framework is presented in this paper for landfill leachate in a whole-system format. This conceptual framework does not only draw together various constituting factors and sub-factors of risk assessment in a logical sequence and categorical order, but also indicates the "what, why, when and how" outputs of and inputs to these factors and sub-factors can be useful. The framework is designed to identify and quantify a range of risks associated with all stages of the landfill lifecycle, and yet in a more streamlined, logical, categorical and integrated format, offering a more standardised and unified whole-system approach.

Risk assessment--encapsulation of both the built and natural environments

Although various risk assessment approaches have been adopted for landfill waste disposal sites, there are still wide-ranging knowledge gaps and limitations which need addressing by developing a holistic risk assessment methodology. This paper conceptually presents only a framework of such a risk analysis methodology for landfill leachate in a holistic format, thereby attempting to bridge these knowledge gaps. The conceptual framework or structure does not only draw together various sections and sub-sections of holistic risk assessment in one place but also categorizes and arranges them in a logical sequence. The holistic structure is to assist in performing the process of a risk analysis from start to end. Also, in order to place Risk Assessment (RA) in a broader perspective of the decision-making process, relationships between Risk Management (RM), Hazard Assessment (HA), and Risk Estimation (R Esti) are also presented. Although this paper attempts to cover the whole of the risk analysis methodology in the form of a fundamental framework, the study does not engage in in-depth detail of sections and sub-sections of the methodology due to brevity.

Solar roads - a new potential renewable energy for Great Britain

Global warming has become a much more realised issue and an immediate threat, accelerating due to the anthropogenic carbon release associated with escalating energy demand. Consequently, pressures are building up to reduce anthropogenic carbon footprint by employing renewable energy resources, among which solar energy is the main. Solar roads are a new and innovative concept as they do not require land to be specifically allocated. This is because the road infrastructure already exists. Therefore, this emerging technique of embedding solar panels into pavements and roadways is becoming a more attractive proposition. However, a hurdle to its successful application is the lack of knowledge regarding its feasibility and viability. This study aims to evaluate the potential of solar roads to inform future feasibility and viability studies in varying contexts and implications. Within the scope of this study, the case of Great Britain is considered to evaluate the potential of how much energy can be generated via the solar roads technology that can be embedded in the country's road infrastructure. A mathematical exercise is performed in which calculations are executed to develop a basic numerical model of the potential. Therefore, the study is quantitative, and the factors considered include seasonal changes, average daily traffic covering roads, tree and building shades, road types and sizes, solar irradiance, solar panel types, and alike. It is estimated that solar roads may supply up to 96.42% of the UK's total electricity, which is a substantially promising potential.