Bacterial Contamination Assessment of Groundwater Supplies in TADLA area (Morocco)

Abstract

The contaminated groundwater could have serious health effects, while the microbial contamination which could cause diseases and dysentery. The groundwater in TADLA aquifer is the main water source in the region, which is mainly used in agriculture, industry, and as a source of drinking water. This study was carried out in TADLA region, in Beni-Mellal-khenifra province, where the study area extends over a large surface of 3,600 km2, of the middle basin of Oum-er-Rbia. This study aims to assess the state of microbial contamination of the groundwater in the irrigated area of TADLA plain. this study has done between March 2017 and May 2018, where samples of water from forty-three wells were analyzed in every three-months to extract the rate of pollutions indicators, and precisely, total coliforms (TC), faecal coliforms (FC) and faecal streptococci (FS), using the membrane filter (MF) method and a spatial-temporal mapping in order to map the microbial concentration variation. The results show a positive testing in all wells with more than one colony-forming unit (CFU), and reveal a significant groundwater contamination caused by microbial agents. The analyzes of water samples show that 95.34% of TC, 86.04% of FC and 55.81% of FS exceed 1000 CFU/100mL in every TC, FC, and FS group. The spatial maps show a variation of microbial concentration due to the climate and anthropogenic factors, with high concentration in the Nord-Est and Nord-Ouest of TADLA aquifer. And this is the fact that makes human life in high risk in these regions.