Sea-Tac International Airport's third runway opens on November 20, 2008.

  • By Kit Oldham
  • Posted 11/29/2008
  • Essay 8855
See Additional Media

On November 20, 2008, the new third runway at Seattle-Tacoma (Sea-Tac) International Airport opens to scheduled air traffic when an Alaska Airlines flight takes off for Denver following a dedication ceremony. The 8,500-foot-long runway is the culmination of more than 20 years of planning, construction, and controversy. Planners at the Port of Seattle, which owns and operates Sea-Tac, first recognized the need for a third runway in 1988. Construction began in 1997. Half a million truckloads of fill dirt were hauled to the site to create an artificial plateau level with the existing runways. Crews poured 130,000 cubic yards of concrete and 35,000 tons of asphalt to build the 150-foot-wide, 17-inch-deep runway. Originally estimated to cost $217 million, the new runway ends up costing just over $1 billion.

Exceeding Capacity

Sea-Tac opened with one runway in 1944 and became fully operational in 1949. A second runway was built 800 feet to the west in 1970. The narrow separation between runways prevented simultaneous use of the two runways during fog and low clouds, or about 44 percent of the time, and capped the airport's efficient capacity at about 380,000 operations (landings and takeoffs) per year. As air travel continued to grow, Port of Seattle planners projected in 1988 that by 2000 Sea-Tac operations would exceed that capacity, resulting in significant flight delays during times of limited visibility.

Eight years of further planning, studies, public comment, and controversy followed before the Puget Sound Regional Council, the Federal Aviation Administration (FAA), and the Port concluded that a third "dependent" runway (for bad-weather operations) at Sea-Tac was required to meet the region's future air capacity needs. Planners also spent considerable time and effort looking for a major supplemental airport site in the Puget Sound area before abandoning that effort, at least temporarily (even as Sea-Tac's third runway finally opened in 2008, many officials were again calling for a fourth runway at a supplemental airport, with some identifying Paine Field in Snohomish County near Everett as the logical location.)

Vocal Opposition

Many who lived near Sea-Tac vociferously opposed a third runway, and the day after the Port made the decision to expand official in 1996, the Airport Communities Coalition, which included the cities of Burien, Des Moines, Federal Way, Normandy Park, Tukwila, and the Highline School District, filed the first of numerous appeals of the project. The litigation lasted another eight years and went all the way to the state Supreme Court before the coalition ended its legal challenges in 2004. Although they failed to stop the project, opponents noted they had won major environmental benefits, including improved quality of fill dirt, state-of-the-art stormwater treatment, relocation of a salmon-spawning stream, and creation or enhancement of wetlands.

When the runway opened, Des Moines Mayor Bob Sheckler recognized that, "to their credit, the port has kept up with their environmental commitments" that he called "hard won" through the litigation (Young, "Third Runway Opponents..."). The compliance was not perfect. During the course of construction the state Department of Ecology fined the Port a total of $145,000 for water quality violations resulting from releasing untreated or contaminated stormwater into area creeks. Nevertheless a Department spokesperson indicated that the project's stormwater treatment was ahead of most cities and other airports.

Construction work began in 1997 after the FAA approved the runway, but stopped several times as the result of the ongoing litigation. As a result, it was 2006 before a stream of large trucks, at times running 20 hours a day, six days a week, finished hauling 500,000 truckloads of fill dirt to Sea-Tac. The fill was used to build up a plateau, level with the two existing runways, on which the new runway would be built. The plateau was held in place by a 1,430-foot-long, 130-foot-high retaining wall described as the largest of its kind in North America.

Costs Climb

As runway costs mounted, due in part to litigation delays and additional spending on environmental measures, airlines, whose fees pay some of Sea-Tac's capital expenditures, voiced concern. A 2003 projection pegged the total cost for the runway at $1.2 billion, more than five times the 1992 estimate of $217 million. In 2005 Southwest Airlines cited rising costs at Sea-Tac (some of them attributable to improvements other than the new runway) when it proposed moving its operations to Boeing Field. Alaska Airlines also considered moving to the King County-owned field before County Executive Ron Sims (b. 1948) vetoed the plan.

As it turned out, when the runway opened the final cost of $1.013 billion was somewhat lower than the 2003 estimate. Airline executives still criticized the billion dollar price tag, but Port officials countered that the runway would save four times that amount -- $4.76 billion over 25 years -- in delay costs that would be avoided. The projected savings, which include fuel and crew time, helped persuade the federal government to kick in more than one-third of the new runway's cost. Port officials also imposed fees ($4.50 a ticket) directly on passengers to help pay the runway debt without further burdening the airlines.

Increasing costs at Sea-Tac drew the attention of State Auditor Brian Sonntag, who conducted a performance audit of the Port. In December 2007, the auditor released a highly critical report that said the Port had wasted $97 million in construction contracts. The Port initially disputed the audit charges but hired former United States Attorney Mike McKay to conduct an internal investigation. McKay's report, released in December 2008 weeks after the third runway opened, found numerous instances where Port employees broke state law or Port policy, and 10 instances that he said amounted to civil fraud. When the Port instituted disciplinary proceedings based on the findings, John Rothnie, project manager for the runway, resigned. Seven other employees were suspended or reprimanded for misleading commissioners about the runway's cost. The state audit also triggered a federal criminal investigation that lasted until January 2010 but did not lead to any charges being filed.

Cleared for Takeoff

Meanwhile, work on the runway continued. In 2007, after the massive artificial plateau was in place and level, construction crews poured the concrete for the runway itself: a massive concrete slab 1.6 miles (8,500 feet) long, 150 feet wide, and 17 inches deep. A total of 130,000 cubic yards of concrete and 35,000 tons of asphalt was used to build the new runway, its shoulders, and eight taxiways connecting it to the existing runways and terminal gates. The runway was complete and ready for testing by the summer of 2008. After testing and final FAA approval, Sea-Tac's third runway opened for commercial use on November 20, 2008.

Sea-Tac was one of three U.S. airports opening new runways that day. Before arriving at Sea-Tac, U.S. Transportation Secretary Mary E. Peters attended dedication ceremonies at Dulles International Airport near Washington, D.C., and Chicago's O'Hare International Airport, whose two runways together cost several hundred million dollars less than Sea-Tac's. Peters acknowledged the greater cost but said that the Sea-Tac runway's benefits -- which she called "cutting the delays in half" -- also exceeded the combined benefits of the other two (Klass). After remarks by Peters, Governor Chris Gregoire (b. 1947), and other officials, Secretary Peters signaled air traffic controllers to clear the first takeoff on the new runway.

The first commercial flight to lift off from Sea-Tac's third runway was an Alaska Airlines flight bound for Denver. Soon after it departed, a United flight made the first commercial landing. Whether by design or coincidence, that airplane, like Secretary Peters, had begun the day at Dulles and arrived in Seattle from Chicago.


Tim Klass, "At Last -- $1B Third Runway Dedicated at Sea-Tac," Seattle Post-Intelligencer, November 20, 2008 (; Kristen Millares Young, "Third Runway About to Open, but Will It Fly?" Ibid., November 13, 2008; Young, "Third Runway Opponents See Victory in Concessions," Ibid.; Jennifer Langston and Gordy Holt, "Plan Won't Fly: Sims Kills Southwest's Boeing Field Hopes," Ibid., October 12, 2005; Langston, "Sea-Tac Makeover May Have Been Too Extreme for Southwest," Ibid., July 21, 2005; Larry Lange and Jeffrey M. Barker, "You Know That Third Runway? Sea-Tac's Really Getting It," Ibid., August 20, 2004; Bob Young, "As Third Sea-Tac Runway Opens, Some Seek a Fourth," The Seattle Times, November 20, 2008 (; "Jet to Test Sea-Tac Airport's New Third Runway," Ibid., September 24, 2008; Jim Brunner and Bob Young, "Possible Fraud at Port Focus of Criminal Probe," Ibid., January 8, 2008; Manuel Valdes, "'End Is in Sight' for Third-runway Project at Sea-Tac," Ibid., August 19, 2007; Bob Young, "Port Forces Out 2 Managers, Disciplines 7 Others," Ibid., December 10, 2008; Mike Carter, “Investigation of Port of Seattle Fraud Ends Without Indictments,” Ibid., January 22, 2010; "Sea-Tac International Airport: Third Runway Project" (by Walt Crowley with research by Daryl McClary and Paula Becker) (accessed November 28, 2008); Kristen Millares Young, "Port's Own Inquiry Finds Employee Fraud," Seattle Post-Intelligencer, December 4, 2008.
Note: This essay was updated on February 5, 2009, and again on January 30, 2010.

Licensing: This essay is licensed under a Creative Commons license that encourages reproduction with attribution. Credit should be given to both and to the author, and sources must be included with any reproduction. Click the icon for more info. Please note that this Creative Commons license applies to text only, and not to images. For more information regarding individual photos or images, please contact the source noted in the image credit.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License
Major Support for Provided By: The State of Washington | Patsy Bullitt Collins | Paul G. Allen Family Foundation | Museum Of History & Industry | 4Culture (King County Lodging Tax Revenue) | City of Seattle | City of Bellevue | City of Tacoma | King County | The Peach Foundation | Microsoft Corporation, Other Public and Private Sponsors and Visitors Like You