Three Innovative Stormwater Treatment Approaches for Three Linked Ports of Tacoma Industrial Sites

The Port of Tacoma operates the 23-hectare (56-acre) Olympic Container Terminal, 5-hectare (12-acre) North Intermodal Yard, and 9-hectare (22-acre) South Intermodal Yard located in Tacoma, Washington. All three facilities are completely paved and subject to extremely heavy operational loads to accommodate loading, unloading, storage, and transfer of shipping containers to and from ship, rail, and trucks. Stormwater discharges from all three facilities are covered under the Washington State Department of Ecology Industrial Stormwater General Permit and each facility was required to install stormwater runoff treatment by the end of 2014, primarily due to zinc concentrations exceeding permit-defined pollutant benchmarks. Three different proprietary gravity-based treatment solutions were designed to meet each location’s unique stormwater characteristics and operational needs while meeting Washington’s stringent industrial stormwater treatment performance requirements.