Potential seismic impacts of wastewater treatment plants on soil or water pollution, due to internal vulnerabilities

The paper examines the seismic vulnerability of Greek Wastewater Treatment Plants, addressing a critical gap in the literature on this seismically active country. The proposed methodology aims to determine vulnerability indices based on findings from previous empirical studies, which are analysed visually and represented into GIS to identify the most potentially vulnerable units and areas. These are integrated with the Seismic Hazard Map as well as regional data to provide a comprehensive assessment, revealing regional vulnerabilities, and soil or water pollution at different post-seismic periods. Ιnternal vulnerabilities and potential soil or water contamination are visualized. The spatial distribution of seismic vulnerability and potential pollution in the surrounding area is based on extreme values of indices of vulnerabilities as well as the estimated post-seismic soil or water pollution, at times 0 h, 12 h, and 24 h. The results depict that the spatial distribution is 0–80% for all the seismic vulnerabilities, while that is 20–40% according the indices, per region. Additionally, maps were developed to depict potential post-seismic soil contamination at time intervals of 0 h, 12 h and 24 h, creating a “cloud” near every infrastructure. For soil pollution, 20.5% of the units should experience an increase, while 69.2% should remain constant. Similarly, 35.9% of the units should see increased water pollution, while 59% should remain unchanged. The study highlights that water pollution poses a greater risk than soil pollution. It enables more targeted research and provides valuable information for stakeholders, supporting mitigation strategies, enhanced controls, and preservation efforts focused on the most vulnerable units.