AWWA MTC57620

The Minneapolis Water Works (MWW), located in Minneapolis, Minnesota is currently in the process of developing two low-pressure membrane treatment facilities with a combined capacity of 160-MGD. MWW is employing several novel approaches to the implementation of these membrane projects. This paper presents the results of the procurement process and the associated performance testing results. The MWW process resulted in the utility receiving four proposals, and the performance testing of two systems. The importance of the operational data in evaluating the bids necessitated a unique testing schedule. It was necessary to provide the membrane vendors an opportunity to optimize their operating conditions to ascertain those that are most cost effective. However, it was also necessary to collect data over a sufficient period of time at steady operating conditions to ensure the bid specifications were met and to verify design parameters accordingly. To facilitate these two goals, three testing phases were established: Phase 1 - start up and training; Phase 2 - optimization; and, Phase 3 - verification. The virus challenge testing and compromised fiber testing was conducted on multiple occasions during the performance testing program. The virus seeding tests conducted at various stages of the program indicated that the membranes tested could reject more than 5 logs of viruses, and the integrity of the membrane systems appeared to be sound after the performance testing program. The fiber-breakage tests successfully demonstrated that both the PHT (membrane A) and the DAFT (membrane B) can effectively detect a single broken fiber on full scale membrane modules. Also, once the broken fiber is identified, it can be easily repaired, and the integrity of membranes can be fully restored. Includes tables, figures.