On the effectiveness of reusing treated wastewaters by infiltration ponds in coastal farmlands. Preliminary investigation on insights from the Korba site, Tunisia Habib Chaieb 1* , Lobna Triki 1 , Nabiha Ouerfelli 2 , Mario Laghi 3,4 , Luca Magagnini 3,4 , Omar Tosatto 3,5 , Andrea De Angelis 6 , Flavia Sollazzo 6 , Pietro Teatini 3,7§ 1 DGRE - Direction generale des ressources en eau, Ministere de l’agricolture et de l’environment - Tunis (Tunisie) 2 ONAS - National Office of Sanitation - Tunis (Tunisie) 3 CURSA - University Consortium for Socioeconomic and Environmental Research - Campobasso (Italy) 4 MED Ingegneria SRL – Ravenna (Italy) 5 M 3 E SRL - Mathematical method and models for engineering - Padua (Italy) 6 IMELS – Italian Ministry for the Environment, Land and Sea - Rome (Italy) 7 Dept. DICEA - Department of Civil, Environmental and Architectural Engineering - University of Padua (Italy) Corresponding Authors: * chai_hab@yahoo.fr , § pietro.teatini@unipd.it Abstract: Treated wastewater (TWW) reuse has increasingly been integrated in the planning and development of water resources in Tunisia. Specifically, the recharge of Korba aquifer (Cap Bon) by treated wastewater (TWW) via infiltration basin is monitored since 2008 for the changes occurring in groundwater quality. The aim of the present paper, elaborated in the framework of the EU funded IMPROWARE Project (Innovative Means to Protect Water Resources in the Mediterranean Coastal Areas through Re-Injection of Treated Water) is to review the available data and investigate the impact of recharging a deteriorate aquifer by treated wastewater through infiltration ponds. Key words: Aquifer recharge, Treated wastewater, Infiltration, Water reuse, Mitigation of saltwater contamination, Korba. 1. INTRODUCTION In the last twenty years, saltwater intrusion in coastal aquifers has become an important environmental problem worldwide. The problem is particularly serious in the southern part of the Mediterranean basin, where water demand is rapidly increasing with population and water resources are limited. Tunisia is located in an arid/semi-arid region of the southern shore of the Mediterranean Sea. With per capita renewable water availability of 450 m 3 /yr, Tunisia is among the countries with less water resources in the Mediterranean area (1,200 m 3 /yr per capita is the average for the MENA region), and current trends of consumption and population growth show that it will decline to 350 m 3 /yr by 2030. This is the reason why an important component of the country log-term management strategies to ensure a sustainable balance between water needs and water resources has been detected in nonconventional resources, such as treated wastewater reuse in agriculture, desalination of brackish and sea water and artificial groundwater recharge by both conventional and treated water. The reuse of treated wastewater (TWW) has been applied in the last few decades in Tunisia to direct irrigation of authorized crops like green spaces and golf courses. The interest is now focused on the reuse of TWW to recharge the aquifers, meanwhile solving several health, environmental, agricultural, and socio-economic issues (Lecca et al., 1999). The aim of the present paper, elaborated in the framework of the EU funded IMPROWARE Project (Innovative Means to Protect Water Resources in the Mediterranean Coastal Areas through Re-Injection of Treated Water) is to review the available data on the recharge site at Korba, Cap Bon. The analyses allow for a preliminary evaluation of the effectiveness of reusing treated wastewater by infiltration ponds on this aquifer. The final aim of the study is to suggest adequate solutions to water scarcity, preserving natural regional aquifers, and solving the problem of TWW safe reuse.