Interpreting and modelling field data for wastewater dispersion into sea trough dimensional analysis

This paper deals with the mathematical and experimental characterization of a coastal urban wastewater discharge in the South Tyrrhenian Sea, namely the Golfo di Palermo, western Sicily (Italy). The stretch of water lying before the central part of the capital town receives the wastewater originating from about 200 000 inhabitants. The sewage is currently still discharged on-shore without any prior treatment by a free-surface outfall called “Porta Felice”. The Municipality is currently implementing a plan to connect the sewerage system of these areas to the main wastewater treatment plant; at the moment, however, no mitigation measure has been applied yet and the quality of the Gulf is still largely affected by wastewater discharges. Part of the plan was the characterization of the seawater in the Gulf; to this aim, in August and November, 2005, the Dipartimento di Ingegneria Idraulica ed Applicazioni Ambientali (DIIAA), Università di Palermo, carried out two survey campaigns, each two days long, in which the most important seawater quality features were investigated.