Ecology Department approves permit for new airport runway

Department of Ecology News Release - August 10, 2001

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Ecology Department approves permit for new airport runway

BELLEVUE - The state Department of Ecology (Ecology) has approved the Port of Seattle's environmental permit to construct a third runway and related projects at Seattle-Tacoma International Airport.

The water-quality permit is the final state permit needed to build the project. The port must now pursue a federal permit from the U.S. Army Corps of Engineers.

"This is one of the largest public-works projects ever attempted in the state of Washington," said Ecology Director Tom Fitzsimmons. "The potential effects on water quality and the natural environment are enormous, but the port agreed up front that the project should meet the highest environmental standards."

"The challenge has been to design the project to meet this test," he said. "We are confident that the port's proposal satisfies all local, state and federal environmental protection regulations."

This is the third time the port has sought water-quality certification from Ecology under the federal Clean Water Act. In 1998, the agency issued a permit for the runway proposal, but the port had Ecology rescind the permit because the proposal at that time had identified only about half the wetlands affected by the project. In September 2000, the port withdrew a second permit application because it needed more time to finish key components of the proposal.

The third runway will be located west of the airport's two existing runways. More than 17 million cubic yards of fill will be used to construct the massive, 8,500-foot-long project - the equivalent of 34 football fields, each stacked 300 feet high with material.

Three salmon-bearing creeks - Des Moines, Miller and Walker - are contiguous to the planned runway site. In addition, nearly 20 acres of wetlands will be filled, but the port will replace or enhance wetland functions in each creek basin and create a new 60-acre wetland next to the Green River in Auburn.

"Some people have said the permit process took too long. But given the unprecedented size, scope and complexity of the project, it's a remarkable accomplishment to put together a plan within two years that meets the high environmental standards we all agreed to," said Ray Hellwig, the regional director for Ecology.

"I am proud of the job we've done," he said. "Our review has been thorough, and we have reached a decision that is scientifically sound, technically feasible and legally defensible."

From the beginning, there were three primary environmental concerns that the port needed to address during and after construction. The final plan submitted by the port last week calls for:

Managing storm water to avoid polluting Des Moines, Miller and Walker creeks. The port will construct 15 stormwater ponds and vault facilities. One of the underground vaults will detain up to 88 acre-feet of storm water, equal to nearly 30 Olympic-sized swimming pools. Several other ponds will hold as much as 20 to 40 acre-feet. The port will retrofit its existing stormwater facilities to bring the entire airport property into compliance with state stormwater regulations.
Protecting and restoring wetland habitat. The port will create or enhance 201 acres of wetlands and aquatic habitat, including creating a new 60-acre wetland near the Green River in Auburn. In addition, nearly 6,500 linear feet of Miller Creek will be enhanced to provide better wildlife habitat, leaving the creek in better condition than it was. Nearly 300 septic tanks and tons of garbage also are being removed from the creeks and surrounding areas.
Mitigating low flows in the three creeks, especially during dryer months. The port will capture and store storm water during wet months, then return the water to the creeks to maintain adequate flows during dry months.

Fitzsimmons said that when port officials delivered their final, revised runway plans to Ecology last week, the package was nearly complete. "We plugged in only a few minor adjustments to make the environmental protections complete."

Those conditions include requiring the port to:

Screen the 17 million cubic yards of fill needed to construct the runway to make sure surface and ground waters will not be contaminated.
Route storm water to Walker Creek detention facilities.
Provide two additional acres of wetland buffers in the Miller Creek basin and widen other buffers around one of the port's gravel pits.
Increase water quality monitoring during runway construction and operation.

In addition, the port has agreed to pay for three to five Ecology staff positions to oversee how the port complies with the terms of its permit. Hellwig also said it is possible the permit may need to be amended in the future based on new information or further evaluation of the construction plan.

Contact: Curt Hart, Public Information Manager, 425-649-7009; pager 206-663-1785