AGENCY: Port of Portland, Ore.
GENERAL CONTRACTOR: JE Dunn Construction
ENGINEERING AND DESIGN: Gresham, Smith & Partners
SCOPE: Adding several large storage tanks, pump stations, and a 12,000-square-foot anaerobic treatment facility
COST: $74 million
TIMELINE: 2009 – 2011
Like any organization that releases effluent directly into U.S. waters, airports must meet certain discharge requirements. The U.S. EPA has asked the air transportation industry to voluntarily control pollutants from deicing operations. These federal water quality standards, plus Oregon Department of Environmental Quality effluent limitations , prompted Portland International Airport (PDX) managers to upgrade their deicing runoff system.
Owned by the Port of Portland, PDX was one of the nation's first airports to build and implement a system to capture and process stormwater runoff containing dilute concentrations of deicing materials from both aircraft and pavement. Activated for the 2011–2012 winter season, the system is comprised of several large storage tanks, pump stations, and an onsite, 12,000-square-foot anaerobic treatment facility. The result: an effluent discharge treatment process that protects the nearby Columbia Slough and Columbia River.
Such a major infrastructure expansion at a high-traffic airport posed many challenges.
“For construction to be efficient and yet allow the airport to operate, the solutions we provided had to be innovative,” says Bruce Van Hine, project manager for general contractor JE Dunn. “Not only were our efforts successful, they were fun to be a part of.”Complying with discharge standards
Before 2003, the airport's primary runoff controls were best management practices to capture, collect, and ship off to appropriate facilities that could handle the overflow. Previously, discharge was metered out to the Columbia Slough when the flow in the slough was active. When the slough was low or had no flow, or when the discharge amount was greater than the Port's permit would allow, the effluent went into the municipal sanitary sewer system or occasionally exceeded the permit limits. Although the airport effectively collected runoff, it couldn't meet state requirements 100% of the time.
The new system doubles the Port's existing treatment capacity. More than 200 new inlets collect ramp and runway runoff. The contaminated runoff is conveyed to storage tanks and reservoirs, then goes through through an anaerobic treatment process.
“A state-of-the-art, onsite anaerobic processing facility in the new treatment building is at the heart of the project,” says Susan Aha, Port of Portland deicing program manager. “It is the largest of its kind in the United States, and one of three in the world to use this specific treatment technology.”