Design Considerations for Tertiary Membrane Filtration: Pilot Unit Operation at a Trickling Filter Facility

Lake Arrowhead Community Services District (LACSD) is overcoming challenges related to the water scarcity and growth under the constraints and operational patterns that put further strain on their ability to implement conventional solutions. The challenges include physical location of the community, cold weather, extreme flow peaking, mountainous terrain and protected species limiting plant site modifications. Recycled water treatment using advanced technologies with small footprints provides added value for communities like Lake Arrowhead. Given the best available technologies for water management, an evaluation of the technology alternatives was completed and a comprehensive pilot testing program was undertaken by LACSD. The goal was reliable design and operations planning for the new recycled water facilities. The membrane pilot unit was operated for a 9-month period at this trickling filter facility. The findings showed that a closer look at the system parameters, water quality and biofouling potential is needed at similar facilities, and a conservative design approach can be one of the solutions to meet production capacities.