The $419,000,000 Port of Seattle consolidated rental car facility is the Aviation Division’s first sustainable demonstration and sustainable asset management pilot project. It is being designed, built, and operated in as economically and environmentally advanced manner as possible and is seeking LEED certification. During peak periods, the garage will hold between 12,000 and 14,000 cars. WaterTectonics was hired to provide technical consulting services around options to treat the full flow stormwater runoff during a 100 year storm event with consideration given to a high water table and limited detention availability. WaterTectonics collaborated with project engineers to reconfigure the site and ultimately provide redundant 300gpm mobile treatment systems for site stormwater treatment. In addition, WaterTectonics also provided a small batch treatment that allowed for filtration and reuse of up to 85% of truck wash water.