ORIGINAL ARTICLE Impacts of wastewater irrigation in arid and semi arid regions: case of Sidi Abid region, Tunisia Salem Bouri Æ Habib Abida Æ Hafedh Khanfir Received: 12 December 2006 / Accepted: 2 April 2007 / Published online: 24 April 2007 Ó Springer-Verlag 2007 Abstract Impacts of irrigation with treated wastewater effluents on soils and groundwater aquifer in the vicinity of Sidi Abid Region (Tunisia) are evaluated. The groundwater aquifer was monitored by several piezometers, where monthly water levels were registered and groundwater salinity was evaluated. This resulted in characterizing the spatial and temporal evolution of the hydrochemical and hydrodynamic properties of the aquifer, showing thereby the impact of artificial recharge. Piezometric maps for pre- recharge and post-recharge situations were developed and a comparison study of both piezometric situations was con- sidered. The piezometric evolution map showed a gener- alized rise of the piezometric level in the vicinity of the irrigation zone. The extent of recharge was shown to in- crease with time as the groundwater level increase, which was localized in the vicinity of the irrigation area, reached more extended zones. Several groundwater samples were withdrawn from wells and piezometers and analyzed. Examining the corresponding physical and chemical parameters showed an increase in the concentrations of nutrients (28 mg/l for NO 3 and 3.97 mg/l for NH 4 ) in the groundwater aquifer below the irrigation zone, which confirms again the infiltration of treated wastewater efflu- ents. The evolution of soil salinity was examined through chemical analysis of soil samples. Electric conductivities of soils were generally shown to be less than 4 mS/cm while the irrigation water has an electric conductivity that may reach 6.63 mS/cm. This might be explained by the phenomenon of dilution and the capacity of soils to evac- uate salts downward. Keywords Wastewater Á Aquifer Á Piezometer Á Water resources Á Pollution Á Tunisia Introduction The shortage of water resources of good quality is becoming an important issue in arid and semi-arid regions. Therefore, water resources of marginal quality, such as drainage water, saline groundwater, and treated wastewater are considered. Irrigation with wastewater has been prac- ticed for centuries in arid and semi-arid regions. Irrigation with reclaimed wastewater has been used in Israel (Shelef 1991), Cyprus (Hadjivassilis 1991), Morocco (Niedrum et al. 1991), Kuwait, Saudi Arabia, Libya, Egypt, and Tunisia (Arar 1991). Almost all wastewater reuse in developing countries is for agricultural purposes (Crook 1991). Existing guidelines and regulations for wastewater reuse practice in the Mediterranean Basin and the possi- bility of developing uniform wastewater reuse standards presented (Angelakis et al. 1999). Hamoda (2004) rev- iewed strategies of water reuse in the south Mediterranean countries and concluded that it has a great potential in the region. However, appropriate technologies of wastewater treatment and irrigation systems must be developed and implemented in order to promote wide use of treated wastewater in irrigation in the Arab region. Water resources in Tunisia are very limited as a result of naturally arid and semi-arid conditions. Water resources available were approximately 450 m 3 /year per capita in S. Bouri (&) Lab. 3E, E.N.I. Sfax, BP W 3038, Sfax, Tunisia e-mail: salem_bouri@yahoo.fr H. Abida Fac. Sc. SFax, Rte Soukra, Sfax 3038, Tunisia H. Khanfir ARE, CRDA, Sfax, Tunisia 123 Environ Geol (2008) 53:1421–1432 DOI 10.1007/s00254-007-0751-5