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Environmental Assessment Process

EA NEPA process flow chart - thumb nail 
NEPA Process Flow Chart - click image to enlarge.

An Environmental Assessment (EA) is prepared when the impact of a proposed project on the environment is not clearly understood.  The EA describes the extent and level of environmental impact.  The document will either support a Finding of No Significant Impact (FONSI) or indicate that an Environmental Impact Statement (EIS) is warranted.

The information on this page is designed for a technical audience.

Chapter 400 of the Environmental Manual (EM) describes policies that must be considered when completing an EA.

Pre-Scoping

Document Impacts 

Document Review and Inviting Comments

Adopting NEPA Documents Under SEPA Rules

As a matter of practice, Project Teams should complete the NEPA and SEPA environmental review process simultaneously in a single document. When a NEPA document is completed without considering SEPA, that NEPA EA/EIS can be adopted using the form found in WAC 197-11-965 . The form/determination notice is signed according to agency SEPA delegations: the ESO Director signs an EIS/EA, the Region/Mode Environmental Manager signs a DNS.

Document Basics

EA Resources

  • NEPA/SEPA documentation GIS layer available on WSDOT Environmental Workbench - useful for identifying if any larger environmental documents were previously completed in your project area.  The information primarily includes only EA and EIS documents.  For access contact your Region Environmental Coordinator.
  • FHWA Technical Advisory TA 6640.8a .  Section II includes an outline and description of recommended content for each section of the document.
  • WSDOT Limited English Proficiency  web page.