AWWA JAW64269

Red water in drinking water systems is a primary target of consumer water quality complaints, yet no existing model of iron release in distribution systems has adequately addressed the complexities of iron sources and release mechanisms, influences of various physicochemical and biological factors, pipe age and material, and the mix of corrosion products released. In this research, experiments designed to investigate the flux constant were conducted on hybrid and single-material pipelines. Red water in the distribution system was found to be a function of water chemistry and hydraulic conditions and not controlled by corrosion and dissolution processes. The mathematical and pilot-scale zero-order flux model introduced here can be used to calculate and predict iron concentration under any given pipe system, water chemistry, and hydraulic condition. It also can help utilities identify areas of a distribution system that are likely to be problematic as well as those conditions that are conducive to the production of red water. Includes 25 references, tables, figures.