Assessing groundwater quality is a crucial issue for sustainable water resource management in arid regions, where groundwater is the main source of water supply and increasing demand is raising both qualitative and quantitative concerns. The present study aims to assess the physicochemical and microbiological quality of groundwater in the Sidi Rached Plain through monthly monitoring carried out over six sampling campaigns. A total of 156 samples were taken from 12 wells located in the watershed. Obtained results revealed unsatisfactory chemical quality in all 12 wells, mainly due to high levels of mineralization (electrical conductivity, magnesium, and bicarbonate) with respective mean concentrations of 1684 +/- 294 mu S/cm, 54.45 +/- 16.91 mg/l, and 380.54 +/- 43.15 mg/l. In addition, the results indicate nitrate pollution, particularly affecting the municipalities of Ahmer El Ain and Bourkika. The bacteriological quality of the water was unsatisfactory due to the presence of bacteria indicative of fecal contamination, such as fecal coliforms and fecal streptococci, although no pathogenic microorganisms were detected. This nitrate and bacterial pollution represents a major risk to human health and the environment. To guarantee the potability of drinking water, it is essential to carry out regular assessments of borehole quality. Authorities must also encourage groundwater treatment before exploitation.