GIS-based investigation of historic landfill sites in the coastal zones of Wales (UK)

This paper presents a GIS-based investigation of historic landfill sites (closed) located within the coastal zones of Wales, UK. These sites may pose a potential environmental challenge in future due to rising sea levels and coastal erosion. There are 78 historic landfill sites in Wales, most of which are located in coastal zones. These sites were operational between 1920 and 1999 but under the Environmental Protection Act 1990, the Environment Agency UK is not required to monitor these historic landfill sites. There is potential for exposure of the buried household, industrial, commercial or mixed waste types from some of these sites due to coastal erosion of undefended shorelines by wind and waves. Historic landfill sites were ranked on the basis of potential for exposure due to coastal erosion. A GIS-based landfill site ranking was carried out using the estimated coastal erosion for the next 20, 50 and 100 years and the proximity to the coastline. The results showed that 6 out of these 78 sites may be exposed and become a potential source of pollution as a result of coastal erosion at the current erosion rate, provided no artificial defence line is constructed. This study recommends that waste samples be taken from the identified landfill sites for laboratory analysis. On the basis of the buried waste type, future actions can be proposed such as the construction of artificial coastal defence lines.