A total of twenty (20) vertical electrical sounding locations were occupied using the Schlumberger electrode configuration in the Billiri and its environs. The study was aimed at evaluating the aquifer characteristics and groundwater potential as well as assessing its potential risk to contaminant seepage in terms of the aquifer hydraulic properties and protective capacity of the overburden rock materials using Dar zarouk parameters. The results show a lithology that is dominated by sands of various grades with no significant delineable intercalating clay/shale impermeable bed. The study area is characterized by low values of the Protective capacities Pc, of the overburden rock materials and high aquifer porosities and transmissivities. The low value of the protective capacities makes the aquifer system in the area highly vulnerable to surface contamination. High porosity and transmissivity value of the aquifer materials implies highly permeable aquifers with significant storagetivity, which enhances the migration and circulation of contaminants within the groundwater system over large areas. These revelations are indications that the groundwater quality may have been impaired in the area and borehole water samples should be randomly sampled for contaminant loads based on this analysis.