Controlling contaminants in the wastewater at Sea-Tac.
Improving pollutant flow. The Industrial Wastewater System (IWS) system at Sea-Tac Airport collects, conveys, treats, and discharges stormwater runoff contaminated with deicing glycol, jet fuel, and other pollutants resulting from aircraft operations. The IWS system was not properly configured, which caused high-BOD IWS flow to be prematurely bypassed to the lagoon containing treated IWS water. This caused the Port to incur more than $1 million of additional treatment costs and discharge fees annually. Reid Middleton designed civil and structural flow-control improvements to the IWS with a knife-gate valve installed in a new concrete vault structure placed between two existing manholes. Critical to the design’s construction was the shoring analysis and constructability review of shoring options. The site was in close proximity to the end of an active runway and coordination with FAA was another important component.
