Research School for Socio-Economic and
Natural Sciences of the Environment
Research School for Socio-Economic and
Natural Sciences of the Environment

Iosif Marios Scoullos

Date: 13 May 2020
Location: Delft

Dissertation title: 

Laboratory-based assessment of the prevalence of water-borne indicator organisms resulting from the surcharging of combined sewer systems

Environmental Engineering and Water Technology, IHE Delft
Promotor: Prof. Dr. Damir Brdjanovic
Supervisor: Dr. Carlos Lopez Vazquez and Dr. Jack van de Vossenberg


In the last decade, flooding has affected over 697 million people and this number is expected to increase. Floods can cause infections due to the release of water-borne pathogenic microorganisms from surcharged combined sewers and other sources of fecal contamination. This research aims, through laboratory experiments in simulated environmental conditions, to give a better understanding of how the occurrence of indicator organisms Escherichia coli, Bacillus subtilis spores, and bacteriophages MS2 in contaminated shallow water bodies and on different urban and recreational surfaces, such as concrete, asphalt, pavement blocks, sand, gravel, playground rubber tiles and grass, can be sampled and estimated given the sunlight conditions, the concentration of indicator organisms, TSS and the type of flooded surfaces. The observations and results presented can be useful in developing policy-making tools for rapid implementation of appropriate measures to mitigate public health risks after flooding.