AWWA MTC61196

The City of Bonita Springs is located in southwest Florida on the Gulf coast in one of the most rapidly growing areas of the country. Bonita Springs Utilities, Inc. (BSU) is a member-owned not-for-profit utility established to supply potable water and wastewater service within its defined service/franchise area. The franchise area is approximately 60 square miles in size, and includes all of the City of Bonita Springs, Florida and an additional area of unincorporated Lee County. The utility's West Water Reclamation Facility (WWRF) has a permitted capacity of 7.0 million gallons per day (mgd). All of the effluent from the WWRF is sold to an irrigation utility for reuse. To meet the growth in wastewater flows, BSU began planning for a new 4 mgd East Water Reclamation Facility (EWRF) that, like the WWRF, would also be designed for 100 percent reuse of the plant effluent. Membrane bioreactor technology was selected for that facility, in part, because of the high quality effluent that the process produces for reuse customers. This paper discusses the effluent reuse quality requirements, the design of the MBR facility, and in particular the innovative universal design approach that would uniquely allow multiple hollow fiber membrane equipment vendors to compete for the equipment procurement contract. As part of the design process, a "universal design" concept was developed. The idea was to produce a single design that could accommodate two manufacturers of immersed hollow fiber membrane systems to allow flexibility in manufacturer selection for the current project and to allow flexibility in future facility expansion or equipment replacement at the end of its useful life, and for future equipment replacement if one manufacturer's membranes provided a technological advantage over another manufacturer. Preliminary designs were prepared to determine feasibility and estimate what additional capital cost would be required to implement the concept. It was determined that the additional design cost required for the equipment selection phase was warranted; however, the additional capital cost required for construction of the universal design was not justified, in part because of the likely evolution of membrane equipment configurations within the foreseeable future. The system was ultimately designed around the configuration of one equipment supplier. The reason for that design, the benefits of maintaining a universal design prior to procurement, and the method used to develop the universal design concept are discussed in the paper. Includes tables, figures.