As an object lesson to those aviation advocates whose answer to airspace and airport congestion lies in the “more runways” solution, ponder the fate of Seattle-Tacoma (Sea-Tac) International’s third runway. First proposed in 1987, the 8,500-ft, $773 million runway has been held up in hearings and court challenges ever since. Last month, the Washington Department of Ecology approved the airport authority’s runway water-quality plan, requiring storm-water ponds, vaults and retrofitting of storm-water facilities serving the existing runways to reduce contamination. It will also require that the fill dirt used to build the base of the runway be screened. The port has already placed about three million cubic yards of material on land it bought for the runway, but needs 17 million more cubic yards.

As soon as this approval was received, a group called the Airport Communities Coalition, made up of five cities and a school district fighting the runway, appealed the Ecology Department’s decision to the state pollution-control hearings board. The coalition faults the way the water runoff data was collected. It also asserts that plans to build a 20-story retaining wall to hold the fill dirt used to support the runway are hazardous because of local seismic activity. If every legal obstacle to construction of Sea-Tac’s third runway were removed tomorrow, the runway would not be completed until 2006, 19 years after first being proposed. To put that in perspective, it’s as if the runway were built at a rate of 14.6 in. a day over the past 19 years.