Sources-pathways-receptors

One can identify two major categories of uncertainty in EIA data (scientific) uncertainty inherited in input data (e.g., incomplete or irrelevant baseline information, project characteristics, the misidentification of sources of impacts, as well as secondary, and cumulative impacts) and in impact prediction based on these data (lack of scientific evidence on the nature of affected objects and impacts, the misidentification of source-pathway-receptor relationships, model errors, misuse of proxy data from the analogous contexts) and decision (societal) uncertainty resulting from, e.g., inadequate scoping of impacts, imperfection of impact evaluation (e.g., insufficient provisions for public participation), human factor in formal decision-making (e.g., subjectivity, bias, any kind of pressure on a decision-maker), lack of strategic plans and policies and possible implications of nearby developments (Demidova, 2002). 

The conceptual model uses the Source -Pathway - Receptor Paradigm. The paradigm requires that each of the parameters within the model are documented, estimated, measured or recorded. The model identifies the source of any contamination identifies who or what is affected (the receptor) and identifies how the source may reach the receptor (pathway). The collection of field data, observations and estimates confirms whether a linkage exists between the source and receptor. 

Source Watts, R.J., Hazardous Wastes Sources, Pathways, Receptors, John Wiley Sons, New York, 1997. With permission. 

Watts RJ (1997) Hazardous wastes sources, pathways, receptors. Wiley, New York, NY... 

R. J. Watts, Hazardous Wastes, Sources, Pathways, Receptors, Wiley, New York, 1996, p. 168. 

Many countries, including the UK, have adopted a risk-based approach to contaminated land management and use the familiar source-pathway-receptor approach to risk analysis (see chapter by Quint). Here, we highlight some of the recent contributions towards development of the risk assessment for contaminated land management. 

The objective of this phase is to develop a conceptual model for the site, which describes the important source-pathway-receptor linkages for the site and makes a preliminary assessment of their importance. 

Information that has been assembled on potential sources is analysed to identify the types and locations of possible contamination on the site. These are then mapped on to the physical description of the site and an initial identification is made of receptors that might be at risk. Consideration of the possible pathways between potential sources and receptors leads to a preliminary conceptual model for the site, in terms of candidate source-pathway-receptor linkages. The preliminary conceptual model is then tested and refined by observation, during a site reconnaissance. 

New information gathered from additional desk studies and any site investigation is then collated and used to provide more complete descriptions of the candidate source-pathway-receptor pollutant linkages identified in the Phase la report. Each linkage is considered separately and estimates are made of the extent and strength of the contaminant source, its connectivity to the receptor and the level of hazard that is presented to the receptor. Finally, a preliminary assessment is made of the potential harm that hazards may pose to the receptors. From this analysis it is likely that one or more pollutant linkages will be recognised as the... 

Overview. The starting point for risk assessment is knowledge of which source-pathway-receptor linkages are plausible for the site that is being assessed. At this stage, the conceptual model for the site should be completed and agreed with key parties, such as regulators. 

Figure 3 shows a flow diagram for a Phase 2 risk assessment. The first stage of Phase 2 assessment is risk estimation this estimates the potential harm to all receptors within identified source-pathway-receptor linkages. The second stage is risk evaluation this considers the acceptability of potential harm to receptors, and identifies and assesses preliminary options to deal with unacceptable risks. 

With reference to the source-pathway-receptor model described briefly in C3iapter 2, the previous section on control of leachate migration has dealt with the "pathway" element, and more specifically how the leachate may be prevented from entering the pathway (the environment surrounding the landfill). From the... 

This chapter deals with flood risk analysis and assessment. The conceptual model source pathway receptor consequence for flood risk analysis is presented and its components are analyzed. The methodology to extract the predicted probability of coastal flooding from risk sources and pathways, as well as the expected damages from risk receptors axe introduced and examined. Reliability analysis of a coastal system is also briefly discussed. Quantitative methods to define acceptable flooding probabilities on the level of the protected area are presented. Tools such as cost-benefit analysis, utihty models, and the life quality index are introduced to define the tolerable risk of flooding. 

These source-pathway-receptor (SPR) linkages are commonly referred to as pollutant linkages. Guidance on the development of a CSM is contained in a variety of documents for example. Model Procedures for the Management of Land Contamination (Reference 14.29). 

Once the source-pathway-receptor scenarios have been identified the risks associated with each one can be assessed qualitatively (i.e. descriptively). Guidance on assigning the likelihood and consequences to the scenarios is given in Tables 6.1-6.3. 

The first step in any assessment of a site affected by ground gas or vapours is to construct a conceptual model. The desk study and site investigation data should be used to develop this. The first part of the gas risk assessment is to use the model to identify any source pathway and receptor linkages from the conceptual model. If there is no linkage then there is no risk. Once the source-pathway-receptor scenarios have been identified the risks associated with each one can be assessed qualitatively (i.e. descriptively). 

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