http://seattletimes.nwsource.com/html/localnews/2001929044_webrunway14.h tml =20 =20 The Washington State Supreme Court today cleared one of the last major legal hurdles in the more than decade-long fight to build a third runway at Seattle-Tacoma International Airport, removing several environmental requirements that threatened to halt the $1.2 billion project.=20 The court issued the unanimous 40-page decision this morning and Sea-Tac officials were poring over the document's details, but the airport prevailed over opponents on all of the key points.=20 "The initial reading of the ruling is favorable," said airport spokesman Bob Parker.=20 The Airport Communities Coalition (ACC), which has led the legal fight against the runway, was not immediately available for comment.=20 The decision clears the way for Sea-Tac to move forward with building a major portion of the runway this summer. The project, originally slated to open in 2001, is now scheduled to be finished in 2008.=20 The case stemmed from a certificate issued by the state's Department of Ecology that allows the airport to bury nearby wetlands under more than 20 million cubic yards of dirt to make room for the additional runway.=20 The ACC challenged the certificate to the state's Pollution Control Hearings Board, which added 16 conditions it said were necessary to protect a nearby stream and to make up for the loss of the environmentally sensitive area.=20 The Port of Seattle, which runs Sea-Tac, appealed some of the added conditions, including one that required stringent testing of the fill dirt that officials said was impossible to meet.=20 The ruling doesn't end the legal battle over the runway, which airport officials say is needed to prevent growing delays at Sea-Tac during bad weather, when low cloud cover effectively prevents the use of its two closely-spaced runways at the same time.=20 The ACC has appealed a separate federal permit issued by the Army Corps of Engineers to the 9th Circuit Court of Appeals in San Francisco. It is uncertain when that case will be decided. But airport officials say they can continue the next phase of construction regardless of the outcome in that case.=20 The ACC, a coalition of neighboring cities and the Highline School District, have fought the runway expansion since it was first approved, charging the project was unnecessary and would harm the area's environment.=20 Sea-Tac blames legal delays and new environmental regulations, including listing of the Chinook salmon as an endangered species, for doubling the runway's estimated costs from $587 million in 1997 to $1.2 billion today.=20 =20