Environmental risk assessment of groundwater quality and treated wastewater reuse on aquifer recharge: a case study in Korba, Tunisia

Water resources associated with the Mediterranean arid to semiarid environment in Tunisia are at risk of degradation in terms of quantity and quality, especially due to groundwater overexploitation. Therefore, the reuse of treated wastewater (TWW) for the artificial recharge of groundwater has been implemented as an alternative, particularly in Korba coastal area of Tunisia. The aim of the current study was to assess the environmental risk of the groundwater quality as well as the reuse of TWW for Korba local aquifer recharge. On one hand, results showed high levels of chloride, ammonia, and sodium adsorption ratio (SAR) in the TWW and high electrical conductivity, nitrate, chloride concentrations, and SAR in groundwater. Heavy metal concentrations were commonly under the detection limit. On the other hand, groundwater was contaminated with pesticides. Environmental risk monitoring of TWW is fundamental to assess its safety reuse on the aquifer recharge and in presenting a coastal barrier against seawater intrusion. Also, it will allow for more effective allocation of resources in future monitoring programs and it can contribute to the environmental management of the treatment plant.