Washington State Department of Ecology

Sea-Tac Third Runway Water Quality Certification

NEW: On June 7, 2004, Ecology issued an amended 401 Water Quality Certification (1996-4-02325, Amended 2) which incorporates the changes required by the Washington Supreme Court in its May 14, 2004 decision upholding the original certification issued by the Department of Ecology. View Certification document - (pdf, 3.4 mb)

Ecology originally issued a 401 certification for this project on August 10, 2001. Ecology later decided to amend that certification. Ecology rescinded Order Number 1996-4-02325 and replaced it in its entirety with Order Number 1996-4-02325 (Amended-1).

The amended 401 certification was appealed to the Pollution Control Hearings Board, which added 16 conditions. A further appeal was then taken to the Washington Supreme Court. In an unanimous decision dated May 14, 2004, the Washington Supreme Court affirmed some of the Pollution Control Hearings Board’s conditions, overturned others, and modified certain provisions of the amended 401 certification. (View table with more information on the issues.)

For more information, contact Alice Kelly, 425-649-7128.

Background:

The Pollution Control Hearings Board affirmed Ecology's 401 water quality certification with conditions which can be found on pages 135-138 of the Board’s decision. They also lifted the stay on the 401. See the decision for more details.

On Sept. 21, 2001, the Department of Ecology reissued its Section 401 Clean Water Act certification for the proposed third runway at Seattle-Tacoma International Airport. The new certification incorporates language from a settlement agreement reached between Ecology and the Port of Seattle. The Port asked Ecology to clarify language in nine of 149 conditions contained in the permit issued on Aug. 10, 2001.

At the direction of the state Pollution Control Hearings Board, Ecology withdrew its original certification and issued this amended version. The modifications give the Port more clarity regarding Ecology requirements without weakening the permit.

Key changes include:

Changes to clarify the scope and duration of the permit such as:

Wetland mitigation and low flow mitigation requirements apply in perpetuity.
Wetland monitoring is required for 15 years (no change from original permit).
Other monitoring conditions will remain in place for a minimum of eight years.
Clarified when the 401 Certification applies versus the 402 National Pollutant Discharge Elimination System permit.

Other changes were made to clarify specific conditions. For example:

The Port is required to immediately begin twice-monthly hydrologic monitoring that will continue for three years.
The specific wetland monitoring condition for mineral soils mistakenly used 16 inches to surface instead of 10.
The fill acceptance criteria will apply only to those projects which directly impact wetlands or waters of the state, such as the third runway embankment. It also applies to projects that have the potential to directly affect surface or ground water quality, such as relocating the sewer line adjacent to Miller Creek.
Instead of requiring written pre-approval from Ecology before any fill material can be placed on site, the Port will submit supporting documentation. Ecology retains the right to disapprove the fill if review shows fill doesn't meet the criteria.
When fill doesn't meet initial screening criteria, Ecology will allow the Port to conduct additional screening to demonstrate the fill won't cause any environmental harm.
Ecology is requiring monthly instead of quarterly reports for fill placement.
Clarified language regarding the water effects ratio study to allow use of similar tests and to use data from the existing runways as a surrogate for third runway data.

Sea-Tac Third Runway Water Quality Certification

Background:

Key changes include:

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