This study investigated the effect of refinery effluents on different sources of potable water supply in two areas of Niger Delta contiguous host and impacted on communities of Delta State, Nigeria (surface water, shallow well water and borehole water) in Ekpan, its adjoining communities and creeks. Since open and underground water bodies are regarded as final recipient of most environmental pollutant, we sought through the study to provide data on pollutant load of potable water supply of the study area. Cadmium, chromium, lead and manganese were determined using Atomic Absorption spectrophotometry; physico-chemical parameters such as nitrate,nitrite, pH, Biological oxygen demand BOD, Total hardness TH, salinity and electrical conductivity EC were all determined using their standard methods. Surface water of Aja-Etan and Ijala had highest levels of cadmium (1.45±0.01 and 1.20 ± 0.0(mg/l), that of ifie-kporo and Ekpan had highest lead (1.00 ± 0.01mg/l). Ekpan borehole water is more acidic (4.79± 0.01) than others. Agigba and Ajamimogha surface water had highest level of manganese (2.40 ± 0.03 and 2.20 ± 0.03mg/l). With the exception of Ekpan shallow well, BOD and hardness were in highest concentration in surface water. Some of the parameter were above WHO standards and USEPA maximum contaminant level MCL.