Risk Assessment of Modern Landfill Structures in Finland

摘要

The purpose of this thesis was to investigate environmental permits of landfillswith respect to the appropriateness of risk assessments focusing on contaminantmigration, structures capable to protect the environment, waste and leachatemanagement and existing environmental impacts of landfills. According to therequirements, a risk assessment is always required to demonstrate compliancewith environmental protection requirements if the environmental permit decisiondeviates from the set requirements. However, there is a reason to doubt that allrelevant risk factors are identified in current risk assessment practices in order toprotect people end environment.In this dissertation, risk factors were recognized in 12 randomly selectedlandfills. Based on this analysis, a structural risk assessment method was created.The method was verified with two case examples.Several development needs were found in the risk assessments of theenvironmental permit decisions. The risk analysis equations used in the decisionsdid not adequately take into account all the determining factors like wasteprospects, total risk quantification or human delineated factors. Instead of focusing on crucial factors, the landfill environmental protection capability issimply expressed via technical factors like hydraulic conductivity.In this thesis, it could be shown, that using adequate risk assessmentapproaches the most essential environmental impacts can be taken into account byconsideration of contaminant transport mechanisms, leachate effects, and artificiallandfill structures. The developed structural risk analysing (SRA) method shows,that landfills structures could be designed in a more cost-efficient way takingadvantage of recycled or by-products. Additionally, the research resultsdemonstrate that the environmental protection requirements of landfills should beupdated to correspond to the capability to protect the environment instead of thecurrent simplified requirements related to advective transport only.