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Left: Construction of a third runway at Seattle's busy Sea-Tac Airport—for which trucks will haul in 17 million cubic yards of dirt fill—will help alleviate the nearly $100 million additional operating costs incurred yearly due to delays. Photo: Port of Seattle. Above: Stormwater runoff systems throughout the third-runway construction area include sand-filter tanks and an 8×10-foot monitoring station. Photo: Hach Co.
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Miller Creek, a natural stream in the construction area, has been enhanced with poles and wires, which hold shade cloth during warmer months to keep the creek cool until native plants can provide natural shade. Photo: Port of Seattle
The Art of Cooperation

The tough permits involved in the third-runway project are defended staunchly by the Washington State Department of Ecology. Yet Hellwig was quick to acknowledge the cooperation of the Port of Seattle, which agreed to fund a consultant working directly with the state as well as a full-time oversight inspector with an office onsite.

“These third parties support public disclosure requests and assure concerned persons that permits are being met,” he said. “It's the first time the department has been involved with this level of cost recovery, and it demonstrates the good-actor role of the Port of Seattle.”

John Rothnie, airfield program manager for the Port of Seattle, said, “The public affairs groups involved are to be commended for not only communicating with the governor's office and facilitating interface among project technical managers but also enacting outreach with area city jurisdictions and community relations departments. Communication is vital with a project of this size and complexity.”

“There have been minimal public complaints and violations considering the massive size of the project,” said Abbasi. “It truly has been a remarkable effort.”

The embankment and most of the retaining walls are expected to be completed by the end of 2006, with runway completion expected by the end of 2008.

Schlegel is a freelance writer/editor in Fort Collins, Colo.

Stormwater runoff system components

The portable water quality monitoring system that stands between stormwater runoff and steelhead trout streams at the third-runway project at Seattle-Tacoma International Airport in Washington comprises a wide range of equipment and technology, many from Hach Co. Its components include:

  • A Power Prime pump from Bakersfield, Calif. - based Rain For Rent, which delivers settled water for treatment
  • A filtration module consisting of four 48-inch sand-media filter tanks accommodating up to 1000 gallons per minute and can be electrically or solar powered
  • Internal piping, flocculent storage, injection pumps, thermostatically controlled heating elements, and 110-V power outlets
  • pHD differential-method pH sensors
  • SOLITAXsc turbidity and suspended solids sensors, with self-cleaning wiper, immunity to color interference, and measurement range up to 4000 NTU or 150 mg/L suspended solids
  • Two sc100 controllers that each receive measurements from a set of pH and turbidity sensors that automatically control the output diversion valve and log all measurement data.
  • Visual and audible alarms provide an extra degree of control and protection. In case of a power failure, the system automatically diverts all stormwater back to the source to maintain compliance until power is restored.

    With its industrial-strength monitoring instrumentation and automated design, the system has met the needs of the third-runway project. Rain for Rent, which designed the system, has modified similar stormwater systems with different sensors and filtration techniques for managing water-discharge mitigation in micro-tunneling projects.

    “We now see construction projects working in wet weather, even storm conditions, because this type of onsite monitoring and treatment technology allows them to maintain compliant discharges,” said Ray Hellwig, director of the Northwest Region of the Washington State Department of Ecology.