Environmental Review

What is SEPA?

SEPA stands for the State Environmental Policy Act. The SEPA review process identifies likely environmental impacts that may result from construction and operation of a proposed project. Information gathered during the review process helps agency decision-makers and the public understand how a proposal will affect the environment. The information can be used to change a proposal, to reduce likely impacts, or to condition or deny a proposal when adverse environmental impacts are identified. Public and agency input is an important part of the SEPA process.

What is an EIS?

An Environmental Impact Statement (EIS) documents the evaluation and analysis of alternatives, potential environmental impacts, and measures to reduce or eliminate those impacts.

Why did we prepare an EIS?

In March 2015, a team of technical analysts hired by the Port of Seattle completed an environmental review for the proposed rehabilitation of Terminal 5’s wharf and deepening of the adjacent berth area, which resulted in a determination of non-significance (DNS) under SEPA.

Following that determination, the Port of Seattle obtained additional information characterizing potential changes in Terminal 5 cargo operations. Based on this information and interest from neighboring communities, the Port decided an EIS should be prepared for the project. The DNS was withdrawn and a Determination of Significance (DS) was issued with a Notice of Scoping.

An EIS for the Terminal 5 Cargo Wharf Rehabilitation, Berth Deepening and Improvements Project (Terminal 5 Improvements Project) was prepared because the proposed project had the potential to result in significant adverse environmental impacts. An “impact” is something that changes, for positive or negative, as a result of an action. An EIS provides an objective analysis of the likely significant environmental impacts, feasible alternatives, and measures that would avoid or minimize adverse environmental impacts.

Final EIS

The Port of Seattle completed the environmental analysis of the Terminal 5 Cargo Wharf Rehabilitation, Berth Deepening and Improvements Project and issued the Final EIS in October 2016. The Port of Seattle, acting as lead agency for environmental review of the project under SEPA, determined that the Final EIS is adequate and complies with the requirements of SEPA, Chapter 43.21C RCW, Chapter 197-11 WAC, and the Port SEPA Resolution 3650, as amended.

The Final EIS was used by the Port and regulatory agencies for decision-making regarding permits for the proposed project.


Reasonable mitigation measures are identified in the Final EIS to reduce the severity or seriousness of the impacts of construction and operations at Terminal 5. Mitigation regarding air, noise, and transportation were areas of particular interest to the community based on comments submitted during the public scoping period and during the Draft EIS comment period. See below for a summary of the mitigation for the Preferred Alternative.

A process timeline showing Scoping occurred in fall 2015, the Draft EIS was issued in spring 2016, and the Final EIS was issued in late summer 2016.
The Final EIS was issued in late summer 2016.