Port of Seattle Seaport Maintenance Facility Stormwater Compliance

(Seattle, WA)  Landau Associates has provided services to the Port of Seattle since 1990 on over 30 different contracts for airport, marine, and other land-based facilities, and has assisted the Port in complying with the requirements of the Washington Industrial Stormwater General Permit (Permit) at the Port’s Seaport Maintenance Facility (Facility). We assessed the facility’s existing stormwater best management practices (BMPs) in response to a citizens’ group lawsuit, recommended new BMPs, and assisted the Port in responding to the suit. The recommended BMPs were implemented at the facility and immediately achieved compliance with Permit benchmarks after two years of exceeding benchmarks. Following re-issuance of the Permit in 2010, which resulted in more stringent benchmarks, Landau Associates assisted the Port in implementing an innovative treatment BMP at the facility using crushed oyster shells placed inside of existing facility catch basins. Implementation included demonstrating that the source of pollutants in stormwater was aerial deposition of particulates from the adjacent Alaskan Way Viaduct and conducting an All Known Available and Reasonable Technology (AKART) evaluation of the oyster shell treatment BMP. The oyster shell treatment BMP resulted in the Port once again obtaining consistent compliance with Permit benchmarks.