*Article* **A Proposed Theoretical Approach for the Estimation of Seismic Structural Vulnerability of Wastewater Treatment Plants**

**Ploutarchos N. Kerpelis 1,2,\* , Spyridon K. Golfinopoulos <sup>2</sup> and Dimitrios E. Alexakis <sup>1</sup>**


**\*** Correspondence: kerpelis@uniwa.gr; Tel.: +30-2105381364

**Abstract:** The assessment of seismic vulnerability is critical for lifelines such as wastewater treatment plants (WTPs) because failures may result in environmental degradation, deterioration of water quality and human diseases development. The main scope of this research is the testing and application of a rapid, simple methodology for assessing the seismic structural vulnerability (SSV) of WTPs (according to the qualitative method Rapid Visual Screening), using structural variables as indices of these infrastructures. An original new method involving the assessment of the SSV of thirteen steps (four for a sample set of WTPs and nine for an individual one) is introduced following systematic literature retrieval. The analysis highlights twenty one factors that may determine the SSV of WTPs: three factors involving general characteristics, five factors involving seismicity and geotechnical data, six factors involving technical data (including structural data) and seven additional factors about WTPs' materials (concrete and the steel reinforcement of concrete frames). The structural data is analyzed to six additional factors. The implementation of the proposed methodology constitutes a simple, rapid methodological approach for assessing the SSV of WTPs using unique factors that were pinpointed and identified for the first time in this study.

**Keywords:** structural vulnerability; seismicity; Wastewater Treatment Plants; sustainability
