Domestic water supply to residential buildings through hand-dug wells has been widely accepted as a reliable substitute to government owned municipal water supply system in Nigeria. This Paper investigates the effectiveness of Ultraviolet (UV) Water Sterilizers as a suitable replacement of chlorine disinfection in the removal of microbiological contaminants in domestic water supply. Water from an established contaminated well in Ogbomoso, Nigeria, were subjected, simultaneously and in parallel, to chlorine dosing and contact with UV light, over a period of seven (7) days without pre-filtration, and additional seven (7) days with pre-filtration. Pre-filtration was accomplished by the use of a calibrated pressure filter. Effluent water samples were taken daily for the two (2) scenarios to the laboratory for physical, chemical and biological analyses. The results indicated that UV water purification method was more effective only when pre-filtration of raw water was introduced. With monitored prefiltration prior to ultraviolet purification, the colony count, MPN Coliform Organisms and MPN E. Coli Organisms recorded seven day-average values of 1, 0 and 0, respectively. In both scenarios, it was confirmed that UV method produced no bi-products and did not alter the taste, pH or other properties of water, in contradistinction to chlorine disinfection method.