The case for maintaining a disinfectant residual

North American water suppliers should continue to maintain a disinfectant residual until limitation of bacterial regrowth and control of distribution system contamination are better understood. Maintenance of a disinfectant residual in drinking water systems has been the cornerstone of sanitary engineering for nearly a century. The author argues that eliminating the disinfectant residual in North American systems is ill advised until issues related to controlling bacterial regrowth and distribution system contamination are better understood. In the meantime, the water supply industry should direct its efforts toward making disinfection practices compatible with other water quality and aesthetic goals.