Third Runway

How will the new runway be paid for?

Financing for the runway is coming from landing fees paid by the airlines, passenger facility charges (a fee paid on each ticket purchased), bonds issued by the Port and federal grants. No general tax dollars will be used.

What was involved in building the new runway?

The project consisted of five main parts. They are:

• Property acquisition - In order to clear the third runway site on the west side of the airport, the Port purchased and removed more than 400 houses, some apartments and a few commercial buildings in the construction area. We took steps to make this process fair and compassionate for property owners and renters.
• Embankment - Fill material brought the third runway site up to the airfield elevation. We built special temporary highway on-off ramps to help minimize truck traffic impacts in the area. Environmental protection measures include a variety of best management practices, monitoring and stringent stormwater management measures to help protect nearby creeks from runoff during wet weather.
• Airfield - A new parallel taxiway, connecting taxiways, aircraft exits, and utilities are part of the new airfield construction. These features will serve the new runway, which is 8,500 feet long and 17 inches thick, built atop the new fill area.
• FAA facilities & navigational aids - Relocated FAA ground radar for use during bad weather, the airspace radar that tracks flights for regional air traffic control, weather reporting equipment, and communication antennas will serve all three runways. A sophisticated air navigation system for operations in bad weather, weather-reporting equipment, and new approach lights have been installed for the third runway.
• Environmental mitigation - During construction of the runway, we affected about 20 acres of wetlands on the west side of the airport and other areas. To compensate for filling these areas, we took major steps to protect and restore wetlands and creeks in the project area, and furnish replacement wetlands near the Green River in Auburn. The mitigation plan included 113 acres in the airport area and 65 acres in Auburn. We also built stormwater facilities to contain runoff, remove pollutants and protect water quality in the project area.

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Mitigation Plan Highlights

Project area

Our mitigation restored important wetland and stream ecological functions and helped protect the project area from future human impacts. At the same time, we repaired the effects of more than 100 years of human activity such as the channelizing and straightening of Miller Creek, the excavation of channels to drain wetlands and improve farmland, and the removal of native trees and bushes that once shaded the water and provided food sources for fish. In addition to the relocation and restoration of Miller Creek, we also enhanced Des Moines Creek.

Miller Creek before mitigation

Restored Miller Creek

• Relocated 1,000 linear feet of channelized creek to create a sinuous stream channel
• Restored 6,500 linear feet of creek
• Removed riprap; restored natural stream banks, gravel bars and floodplain
• Improved creeks by removing manmade structures
• Converted cropland to wetland and enhanced streams with habitat features and 168,000 native plants
• Installed more than 200 pieces of large woody debris
• Awarded $300,000 in grants for creek restoration projects by community groups
• Will monitor mitigation site for 15 years.

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Off-site replacement wetlands

The replacement wetlands that will restore lost wildlife functions are located away from the airport in compliance with federal advisories that limit creation of water bodies near airports. Water bodies and wetlands attract birds, which can threaten the safety of aircraft. The wetlands filled during construction of the third runway were replaced by about twice as many wetlands at the Auburn site (photo at right), where the Port:

• Converted former pasture into wetlands that provide flood storage and habitat functions, especially for waterfowl
• Planted 182,000 native trees and plants
• Installed 250 pieces of large woody debris and other habitat features
• Will monitor the site for 15 years.

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Restoring and Protecting Water Quality

To improve water quality in Miller Creek, we removed the following sources of contamination:

• Nearly 400 septic tanks;
• Drainage ditches;
• More than 180 underground storage containers, mostly home heating oil tanks;
• Trash, debris, household waste;
• Lawns containing chemical contaminants;
• Streets and driveways in the project area that contributed grease, oil and heavy metals to untreated runoff.

Debris was removed from the area.

Construction Stormwater Management

To protect area creeks from flooding, contamination and sediment we:

Samples of stormwater before and after treatment

• Treated runoff to prevent sediment and pollutants from reaching the creeks. The runoff was stored in seven construction stormwater ponds and four treatment centers. Treatment is with a crabshell coagulant called chitosan and sand filters, which turns cloudy water to clear.
• Mitigated low-water flow in the creeks during the dry season each year
• Provided planted areas that serve as natural filters for stormwater runoff to pass through before going to the creeks
• Infiltrated runoff into the ground using gravel-lined trenches that will drain storm water slowly into surrounding soil and subsequently to the creeks.

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Other Mitigation Measures

Wetlands are protected by a retaining wall.

During construction we also:

• Contained embankment with retaining walls to reduce the amount of wetland filling, and allow buffers on Miller Creek;
• Followed erosion protection guidelines such as silt fences, sedimentation ponds and chemical treatment (as appropriate) to remove suspended fine material from runoff;
• Had a biologist and erosion control engineer on site to monitor construction activities;
• Maintained fencing around wetland and buffer areas during construction;
• Provided spill prevention/cleanup;
• Tested fill material for contaminants prior to use.

Threatened and Endangered Species

A Biological Assessment evaluated impacts of the project on listed species, including Chinook salmon, bull trout, marbled murrelet, and bald eagles. Results of that Biological Assessment showed that the third runway will not have an adverse effect on federally protected fish in streams adjacent to the airport. Regulatory agencies concurred with these findings.

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