Assessment of groundwater vulnerability to point and non-point sources of pollution and mitigation measures for boreholes in the Guelma Plain, Northeastern Algeria

Groundwater quality in the Guelma region of northeastern Algeria has significantly deteriorated in recent years, primarily due to uncontrolled industrial discharges and excessive use of pesticides and chemical fertilizers near water catchment points. This study aims to delineate groundwater protection perimeters for five boreholes located in the Guelma alluvial plain using a combination of hydrogeological and hydrodynamic methods. Three methods; Sichardt, Kusakin, and Cylinder, were applied to define close protection perimeters, while the Infiltration and 3A2E methods were used to delineate remote protection zones. These approaches incorporated parameters such as hydraulic conductivity, transmissivity, drawdown, recharge rate, and groundwater flow direction. The Kusakin method provided the broadest and most realistic estimates for close protection zones, with radii ranging from 52.9 m to 428.1 m and corresponding areas from 0.9 ha to 57.6 ha. Remote protection zones showed radii between 818.1 m and 1293.5 m and areas between 210.2 ha and 525.6 ha, with both Infiltration and 3A2E methods yielding comparable results. The findings underscore the importance of incorporating multiple methods and hydrogeological parameters for accurate and reliable groundwater protection planning. Recommendations are made for restricting potentially contaminating activities within these zones to preserve groundwater quality and support sustainable resource management.