Microbes and Water Quality in Developed Countries

Abstract

Safe drinking water has been a concern for mankind throughout the world for centuries. In the developed world, governments consider access to safe and clean drinking water to be a basic human right. Government regulations generally address the quality of the source water, adequacy of treatment, regular monitoring, and public notification of contamination. Pathogenic microorganisms in drinking water can include bacteria, viruses, and protozoa. Some human pathogens occur naturally in source waters, whereas others are the result of fecal contamination. Some bacterial pathogens are capable of growing within biofilm communities attached to pipe walls in distribution systems. Pathogens can enter a drinking water distribution system via inadequately treated source waters. Most drinking water contamination events occur, however, because of either intrusion of untreated waters into water pipes during periods of low or negative pressure or cross connections with other nonpotable water pipes. Treatment technologies used to remove or inactivate pathogenic microorganisms include coagulation, flocculation, filtration, and disinfection. The presence of a disinfectant residual in the distribution system is critical in maintaining a safe drinking water supply.