Microbial quality assessment of Beni Aamir and Beni Moussa groundwater (Tadla plain-Morocco)

The groundwaters from the deep aquifers of the Tadla are mainly used for agriculture, industry, and drinking water. To assess the state of microbial contamination of the groundwater in the irrigated area, a study has been carried out over a 1 y period from March 2017 to May 2018. A total of 43 wells are selected and the water has been analyzed every 3 months to quantify the coliforms (TC), fecal coliforms (FC), and fecal streptococci (FS) using the membrane filter (MF) method, and also to perform a spatial -temporal mapping in order to clarify the concentration of pollution using the Surfer software. The result has revealed significant groundwater contamination by microbial agents. The analyzes of TC, FC, and FS indicated that 95.34%, 86.04%, and 55.81% of the wells tested to exceed 1,000 CFU/100 mL respectively, for each TC, FC, and FS group, where 100% of the wells have positive results, that is, having more than one colony-forming unit (CFU). However, spatial variation maps show concentrations of the microbial indicators, which are varied according to wells location, and due to the different sources of contamination. Fluctuations in microbial concentrations are probably influenced by the sampling season in both dry and rainy periods and also by anthropogenic activity. The study appoints a serious risk that threatens the environment and human life.