The goal of this project is to provide an assessment of the cost benefits of point-of-use (POU) water treatment at the tap in terms of protection from contaminants in drinking water. While POU water treatment benefits have been demonstrated, the cost benefit relationship has not been characterized previously. This study is novel in that a holistic approach was used to document individual and population benefits of single and multiple contaminant removal. Both chemical and microbial contaminants were considered. Contamination risks exist in all water supplies no matter how well they are treated. This is because of treatment failures, post-treatment intrusion of microbes and chemicals, and regrowth of pathogenic organisms in the distribution system. The inability of treatment plants to remove all contaminants all of the time, require the use of a final POU treatment barrier to minimize exposure risks.