AWWA IMTECH59637

In 2003 and 2004, Water System Master Plans were completed for the cities of Glendale, Arizona and Mesa, Arizona. Extended period simulation (EPS) water age and source trace analyses were conducted and used in conjunction with treated water quality curves of disinfection byproduct (DBP) formation potential to evaluate the water quality impacts of various alternative improvements. This paper presents the methods and results of detailed evaluations of distribution system water quality as conducted for these two systems. Both Glendale and Mesa receive treated water from two water treatment plants, with each plant having different DBP formation potential. In addition, treated water from the plants is supplemented by direct input of groundwater from wells located throughout the distribution system. In addition to water age analyses, source tracing analyses were required to evaluate the source of treated water throughout the distribution system. Effective presentation of the modeling results, in a manner that can be interpreted and readily understood, allows for effective quality control review and increased confidence in the resulting recommendations. This paper presents details on the presentation of the results of the EPS water age and source tracing analyses for Glendale and Mesa. Includes table, figures.