Assessment of water quality using physicochemical and bacteriological parameters in Oued Mchera (Bouregreg Basin, Morocco)

This study examines changes in physicochemical and bacteriological parameters in Oued Mchera water from the Bouregreg Basin to determine their pollution level and the factors responsible for it. Our investigation, conducted in 2021, focused on five specific stations within Oued Mchera. Nine physicochemical parameters were assessed on a spatio- temporal basis to calculate the water quality index (WQI). Furthermore, the levels of faecal coliforms (FC), Escherichia coli, and total coliforms (TC) were evaluated at these specific stations. The findings indicate that the pH average values vary between 7.59 and 8.78, the electrical conductivity average values range from 923 to 8300 μS∙cm−1, and the dissolved oxygen (DO) levels range from 3.13 to 3.06 mg∙dm−3. It should be noted that the high levels of conductivity, sodium, and temperature have a detrimental impact on the growth of bacteria. Furthermore, elevated salinity hinders the proliferation of FC, E. coli, and TC. The presence of E. coli is inversely related to the levels of DO and NO3−. This research’s WQI demonstrated notable temporal differentiation, clearly indicating differences in various seasons and stations both upstream and downstream. In addition, the WQI indicates that the water from all stations is not suitable for drinking throughout the dry and wet periods. The findings underscore the immediate need for coordinated efforts to mitigate the detrimental impacts of pollution on the water quality of Oued Mchera. Urgent implementation of stringent regulatory actions will be needed to curb the release of home and agricultural wastewater into the study area.