AWWA REUSE52117

Irvine Ranch Water District (IRWD) was one of the first water suppliers to pioneer the installation of the dual plumbing systems in high rise office buildings located in south Orange County, California. Currently, the recycled water blend from the District's water reclamation plant and open storage reservoirs is used in the high rise buildings for toilet flushing. Most of the high rise buildings are equipped with pleated cartridge filtration systems sensitive to fluctuations of the influent water quality. However, these systems are prone to plugging, breakdowns and high maintenance costs. The objective of this project was to find suitable filtration systems with lower maintenance costs for high rise buildings. Initially, IRWD identified two technologies for excess turbidity removal in high rise buildings. One was a bag filter technology utilizing multilayer polypropylene or polyester and nylon, high loading capacity, double length bag filter elements arranged in fiberglass or steel cylinder housings. The other was a self-cleaning automated filter process, utilizing a drum with backwashable cassettes and a sophisticated high pressure rinse system. This paper presents the results of pilot testing which determined that bag filtration might be the most efficient and feasible system for the high rise building applications. Includes 4 references, tables, figures.