Mix it up

摘要

As regulations tighten, utilities striving for optimum water quality are turning their attention to the distribution system. It is in the distrubution system that even the highest quality water leaving a treatment facility can significantly deteriorate before reaching customers. Stored water can become stagnant and stratify due to factors such as underutilization, short-circuiting, pipeline distance and size, solar heating, and inlet/outlet pipe configuration. Under these conditions, especially in the thermally isolated upper layers, water ages and can completely lose its disinfectant residual, the final barrier that prevents bacterial regrowth and protects consumers from waterborne illness. Despite today's advanced treatment and disinfection technologies, water utilities are discovering that the simple process of mixing is a cost-effective way to maintain the highest possible quality water in storage facilities. Public water distribution systems store larger-than-normal volumes to provide for peak demand, pressure regulation, fire protection and other emergencies, and future growth.