US regulations on residual disinfection

Most community water systems in the United States disinfect their water. Ho wever, only surface water systems are currently required to provide a disin fectant residual in the distribution system. This article reviews existing regulations, including the surface Water Treatment Rule and the Total Colif orm Rule, for maintaining a disinfectant residual and outlines their requir ements. It also discusses forthcoming and long-term regulations and how the y may affect water treatment and distribution system water quality, operati ons, and maintenance.