Assessment of the Bacteriological and Physicochemical Water Quality of the Inaouene and Larbaa Rivers (Taza,Morocco)

In the region of Taza and Oued Amlil cities, an alarming environmental issue related to wastewater and solid wastes unfolds in the absence of an effective management strategy. Large quantities of wastewater from Taza (5.03 mm³) and Oued Amlil (4.2 mm³) in 2022 find their way directly into the river environment. In response to this critical situation, we conducted a bacteriological pollution survey of the waters in the Inaouene River and its tributary, Larbaa stream, to further evaluate potential damage during two distinct periods (July 2022 and January 2023). Our investigation revealed a concerning level of contamination. Mesophilic Flora at 37°C (TAMF), Total Coliforms (TC), Fecal Coliforms (FC), E. coli (E.C), Fecal Streptococci (FS), Sulfite-reducing Clostridium (ASRC), Intestinal Enterococci (IE), Pseudomonas aerugenosa (PA), Staphylococcus aureus (SA), and even Salmonella were found to be at notably high concentrations. This contamination wasn’t confined to one location; both the Inaouene River upstream and the Larbaa stream downstream were impacted. Furthermore, bacterial contamination portrays a decreasing gradient from upstream to downstream. The statistical analysis of the physicochemical and bacteriological data uncovered significant temporal variations (p-value < 0.05) for TC, FC, EC, SA, PA, T, TUR, EC, and DO. Conversely, some factors like ASRC, TAMF, FS, IE, and PH showed no statistically significant temporal variations (p-value > 0.05).