Physicochemical and Bacteriological Quality Assessment of Water Downstream of the Kaddoussa Dam in Boudnib, Morocco

Abstract

This study addresses the pressing need to evaluate the quality of water resources in the Oued Guir watershed, highlighting the importance of monitoring both surface water and groundwater in the context of environmental and public health. It focuses on the evaluation of physicochemical and bacteriological water quality downstream of the Kaddoussa Dam, as well as the characterization of wastewater from the Boudnib treatment plant discharged into Oued Guir. The goal is to assess the health of aquatic ecosystems and understand the impact of anthropogenic activities on these sensitive environments. A comprehensive analysis was conducted at 15 selected stations during a sampling campaign in November 2023. Groundwater and surface water were assessed using 10 physicochemical parameters, while bacteriological quality was evaluated based on fecal coliforms and Escherichia coli. In addition, 38 parameters were studied to characterize the wastewater discharge. All analyses followed standard procedures and the results were compared to Moroccan and World Health Organization (WHO) standards. The study revealed that surface water and groundwater in the study area exhibited strong mineralization, with Electrical Conductivity (EC) exceeding 1400 µS/cm at all stations. Nitrogen quality, in terms of Nitrates (NO3-), was moderate across stations, while Ammonium (NH4+) quality was consistently excellent. Physicochemical parameters of surface waters indicated overall excellent quality. Bacteriological analysis showed minimal contamination by fecal coliforms and Escherichia coli, with levels deemed negligible. However, wastewater from the Boudnib treatment plant exceeded Moroccan standards for organic load, presenting a potential environmental risk.