Human beings especially in developing countries depend on different water sources for domestic purposes. Water sources found near agricultural areas and mining activities, may end up contaminated and hence not suitable for human consumption. This study aimed at determination of the economic activities carried out near the water sources of Busia district; investigation of the presence and concentration of selected heavy metals in the water sources; and investigation of the likely health effects brought about by the consumption of water polluted with heavy metals to the population in Busia district. Water samples from twenty-nine point water sources were collected during wet and dry seasons, and analyzed for the presence of some selected heavy metals using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP – OES). Information concerning health issues of the respondents were collected using the questionnaires. The concentrations (mg/l) as expressed in terms of mean ± standard deviation in domestic water sources including streams, ponds, protected springs, shallow wells and boreholes were within the acceptable range for copper, lead and mercury while arsenic values were above the acceptable limits according to WHO and EAC standard limits. Abdominal pains and diarrhea were the most reported common diseases that affected the population who consumed water polluted with heavy metals. The study recommended that Government officials especially from the Ministry of Health should carry out awareness about safe water uptake to avoid diseases that result from consuming contaminated water. In addition, there should be constant monitoring about the concentration levels of heavy metals in domestic water sources in order to avoid or scale down the spread of diseases due to consumption of water contaminated with heavy metals. The residents should be encouraged to use water from tap and shallow wells for domestic purposes since they contain small traces of heavy metals as compared to other water sources.