Groundwater plays a critical role as the primary source of domestic water supply in Jimeta, Yola North, and across many developing regions. However, improper refuse disposal practices continue to threaten its safety. This research assesses the impact of the Jimeta open waste dumpsite on surrounding groundwater quality by analyzing twenty water samples from hand dug wells (five samples) and boreholes (fifteen samples). Portable instruments were employed to obtain pH values, total dissolved solids (TDS), electrical conductivity (EC) and temperature readings in the field. The titrimetric method was also employed to analyze total hardness, chloride, and dissolved oxygen. Sodium (Na) and potassium (K) were analyzed using atomic flame emission photometry, cations and heavy metals were analyzed using the spectrophotometric method. The results showed EC, TDS, nitrate, chloride, calcium, magnesium, cadmium, and lead higher than World Health Organization (WHO) indicating significant contamination. Water Quality Index results reveal that 90% of samples fall within poor, very poor, or unsuitable categories for drinking. This study indicates that the interaction of rainwater with open dumpsites dissolved soluble harmful substances which infiltrate the subsurface and pollute the groundwater in the study area. Urgent interventions; including engineered landfills, regulated waste disposal, and routine groundwater monitoring are required to mitigate health risks.