NEPA & SEPA guidance

Use the guidance on this page to appropriately disclose potential project impacts through the NEPA and SEPA (National and State Environmental Policy Acts) processes for Washington State Department of Transportation (WSDOT) environmental documents. Documents prepared under Local Programs (LP) should visit the LP Environmental Services webpage.

Read Environmental Manual Chapter 400: Environmental Review and Transportation Decision Making (PDF 592KB) to learn more about our NEPA and SEPA processes as shown in the graphic below.

View this graphic for an overview of the NEPA process (PDF 505KB).

Documenting environmental impacts through NEPA

The level and type of analysis required for a project varies by discipline and depends on the significance, complexity and contextual setting of the actions being taken. Although most of the agency’s projects fit categories of exclusion, the complexity of the EA/EIS processes requires more guidance.

Before you begin documenting project impacts, read these documents to understand the Washington State Department of Transportation’s (WSDOT) role in the environmental documentation and review process of a federal project:

The FHWA Stewardship and Oversight Agreement with WSDOT (PDF 1MB) documents roles and responsibilities related to project approvals and methods of oversight to deliver the Federal-aid Highway Program in accordance with Federal requirements.

The Federal Nexus Requirements (PDF 736KB) table can help you understand which regulations your project must comply with based on your federal nexus.

Projects not likely to cause significant adverse environmental impacts are classified as NEPA CEs (National Environmental Policy Act Categorical Exclusions). Use this page to determine your project type and to understand the process for documenting project impacts for NEPA CE approval.

Follow directions on this page to complete your Environmental Assessment (EA) and Environmental Impact Statement (EIS) for NEPA (National Environmental Policy Act) documentation for a state transportation project.

This page guides project teams in the preparation of environmental impact statements (EISs) and environmental assessments (EAs), but many of the tips also apply to categorical exclusions (CEs). This page also provides resources for authors and reviewers to ensure NEPA/SEPA (National/State Environmental Policy Act) documents are of high quality and readable to the general public.

Our SEPA (State Environmental Policy Act) actions include documenting environmental impacts for our actions and commenting on other agency actions.

14 fish passage projects were completed in 2020

improving access to 54.2 miles of upstream habitat.

11,959 incidents responded to

by WSDOT’s incident Response teams during second quarter of 2021, 15% more than same quarter in 2020.

41 Pre-existing Funds Projects Advertised

during the eighth quarter of the 2019-2021 biennium.