Major construction is now complete on enhancements to the Portland International Airport deicing system. Following construction, the Port went through a seven-month start-up testing process to ensure the system operated as designed. That process was completed in April 2012 and the system is now fully operational.
The Port designed the enhanced system in partnership with PDX air carriers and regulatory agencies to better protect water quality in the Columbia Slough. The enhanced system:
- Expands the existing system to capture stormwater runoff containing deicing materials from the western airfield
- Increases storage capacities for concentrated and dilute runoff
- Adds an on-site anaerobic treatment facility
- Includes a Columbia River outfall, which was completed in January 2010
- Will treat concentrated runoff prior to discharge to the Columbia River in compliance with permit requirements
An environmental review of the project was completed in September 2009. This process included an approved National Pollution Discharge Elimination System permit from the Oregon Department of Environmental Quality and a Biological Opinion from the National Marine Fisheries Service. The Biological Opinion determined that there would be no significant impacts from project construction and operation to endangered salmon in the Columbia or Lower Willamette rivers.
The entire project is part of an agreement with DEQ to ensure the Port meets environmental regulations for deicing operations while maintaining safe airport operations. The Port was required to have a fully operational expanded system by April 30, 2012. With completion of this milestone, the Port will shift to the National Pollutant Discharge Elimination System permit managed by DEQ. Under this permit, during the deicing season, more runoff will likely be sent to the Columbia River, instead of the Columbia Slough, which has lower flows and volume.
The Port's original deicing stormwater runoff collection system became operational in November 2003, after extensive collaboration with citizens, airlines, the DEQ, the Columbia Slough Watershed Council and other stakeholders. The $31 million system took three years to construct. It protects the Columbia Slough through the monitoring, collection, treatment and controlled release of deicing stormwater runoff to the slough and City of Portland sanitary system.
DEQ regulates the discharge of deicing stormwater runoff to the slough through a deicing permit issued to the Port of Portland and co-permittees. Deicing runoff can temporarily reduce dissolved oxygen in water as it biodegrades. The reduced dissolved oxygen can be unhealthy to aquatic life.
During the winter seasons of 2003-2004, 2004-2005 and 2005-2006, low water flows in the slough contributed to exceedances of the deicing permit. Although the deicing system worked well, the low rate of water flow in the slough limited the discharge of deicing stormwater runoff. In response to the exceedances, the Port and co-permittees constructed a number of system modifications beginning in 2003, at a cost over $4 million, to further improve the system's effectiveness. In 2006, the Port and air carriers began work on a larger project to enhance the original system. Port Commissioners approved a conceptual design of more significant enhancements to the deicing system in May 2007. The project team completed schematic design in June 2008 and final design in June 2009, and the resulting work was completed in time for the 2011-2012 winter season.