Baseline study in environmental risk assessment: Escalating need for computer models to be whole-system approach

Abstract

Despite landfills having the potential to pollute the environment both during their operation and long after they have ceased to receive waste, they remain a dominant waste management option, particularly in the UK. In order to combat the environmental pollution caused by landfills, risk analysis is increasingly being employed through computer models. However, for a risk analysis process to be successful, its foundation has to be well established through a baseline study. This paper aims to identify knowledge gaps in software packages regarding environmental risk assessments in general, and especially those that have been developed specifically for landfills and landfill leachate. The research establishes that there is no holistic computer model for the baseline study of landfills, which risk assessors can use to conduct risk analyses specifically for landfill leachate. This paper also describes a number of factors and features that should be added to the baseline study system in order to render it more integrated -thereby enhancing quantitative risk analysis, and subsequently environmental risk management.Keywords: baseline study; preliminary investigation; computer models; software packages; landfill leachate; risk analysis; risk assessment; waste disposal sites. BACKGROUNDThe advent of the industrial revolution led to the expansion of human populations and urban living, which in turn drove increasing economic growth at national and global levels. Unfortunately, this increasing prosperity resulted in ever-greater quantities of waste being generated. There is a link between economic growth and waste and this link is still evident today as industrial, commercial, and domestic waste streams. Waste is the inescapable outcome of the activities which 3 characterise human society; indeed in one sense it is an indicator of the health of modern economy (Tromans and Stiles, 2004). A most recent evidence of strong and directly proportional relationship between economic growth and waste generation is the deceleration impact of the current economic downturn on the amount of waste. Statistics in the USA alone indicate that waste generation had always been escalating until 2007, when the downturn struck. In the years following 2007 the generation of waste has reduced (EPA, 2010). The same has been the case in the UK in various sectors (MBD Ltd., 2011).There are two main issues regarding waste. One is the amount of waste that is generated, and the second is how it is dealt with or managed -where landfilling still is the most predominant waste management option (among others that include re-use, recycling, composting, and incineration). Regardless of the economic downturn impact, due to increasing environmental legislation and socio-environmental pressures, overall reduction has been noticed on both fronts of waste -that is, in the generation of waste as well as in the amount of waste that is landfilled in various regions, states and countries. However, this is not the case everywhere around the world.Furthermore, the ...

Development & application of Conceptual Framework Model (CFM) for environmental risk assessment of contaminated lands

“…The data from this module will be helpful in the “exposure assessment stage” of a “risk assessment” in relation to identify pathways that lead from hazards to receptors. This hydrogeological information also establishes the direction of leachate flow ( Butt et al, 2017a , Butt et al, 2017b ). Regarding topography of MBODS, ( Mahmood et al, 2016 ) also illustrated that residential area exists at South of site and population will be at risk from contaminated land.…”

“…The data regarding geology aspect can contribute to the follow-on stages of “risk assessment” in several manners. For example, geological data may illustrate the length of “unsaturated zone” of the pathway that leads from the landfill to a given “environmental receptor” ( Butt et al, 2017a , Butt et al, 2017b ). Geological data can also explicate “chemical reactions” that may take place between “leachate contents” and “geological materials”, etc.…”

“…Dumping sites are more common in developing world due to a lack of resources and management expertise ( Ferronato and Torretta, 2019 ). These sites are considered as a pollutant source that may have the ability to contaminate all the four main spheres of the environment i.e., lithosphere, hydrosphere, atmosphere, and biosphere ( Butt et al, 2017a , Butt et al, 2017b ).…”

“…It is also found that all the above-mentioned models are very expensive. The closest possible match of holistic model was proposed by Butt et al, 2017a , Butt et al, 2017b but that model has several knowledge gaps like that model is still a conceptual model, not ready-to-use; its practical application was not illustrated to a real-world landfill and it only covers landfill leachate.…”