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National Environmental Policy Act (NEPA)/State Environmental Policy Act (SEPA) Support

The National Environmental Policy Act requires disclosure of potential impact to all aspects of the built and natural environment.  The level and type of analysis varies by discipline and is determined by the complexity and contextual setting of the project.  The Environmental Services Office provides support and assistance to WSDOT staff to ensure that the appropriate level of analysis is completed.   

This page contains technical information and is intended for a technical audience and provides links to subject matter experts and analysis procedures for:

Land Use and Transportation

The Practical Design process (Design Manual chapter 1100) analyzes the relationship between land use, transportation, and community values to determine land use and transportation context is and develop practical, sustainable improvement projects.  NEPA documentation should build on the contextual information used as the Basis of Design (BOD) for the project.  Contact the HQ NEPA Specialist for assistance.  Projects should be consistent with local comprehensive plans, address unusual circumstances such as wild and scenic rivers and farmland conversion.


Cumulative Effects

Federal and state environmental regulations require consideration of indirect and cumulative impacts to provide decision makers with an understanding of the relationship between short-term uses and long-term productivity of the environment.  Policy for completing the analysis is found in Chapter 412 of the Environmental Manual.  Guidance for completing the analysis is available in the Joint Guidance on Preparing Cumulative Impact Analysis.  For assistance contact the ESO Policy Branch Manager.


Social and Community Effects

WSDOT studies the effect of transportation projects on the communities they travel through. This analysis is done in addition to the Environmental Justice for EA and EIS level projects.  Focus you analysis on the issues of greatest local interest based on feedback from community outreach efforts and the Basis of Design (Design Manual chapter 1100.10).  Contact the HQ NEPA Specialist for assistance.

  • 12-Step Social and Community Effects analysis process (pdf 91 kb)
  • Defining the study area (pdf 70 kb)
  • Frequently asked questions about Social and Community effects (pdf 82 kb)
  • A variety of analysis tools are described in NCHRP Report 456: Guidebook for Assessing the Social and Economic Effects of Transportation Project.  FHWA endorses the analytical tools described in the report, but does not feel the public involvement is adequately described or incorporated.  Keep these issues in mind when using NCHRP 456 (pdf 80 kb).
  • Relocation impacts are evaluated using the process described in the WSDOT Right of Way Manual M26.01.
  • The process for evaluating a project's impacts to minority and low-income population is described on the Environmental Justice web page.


Economic Analysis 

Analysis and documentation of the economic impact of a transportation project is only done for very complex projects where:

  • A significant amount of land is converted to transportation uses.
  • Economic development is a primary purpose of the project (as stated in the project Purpose and Need).
  • The project provides access to undeveloped rural land.

The analysis should focus on the change in tax base caused by the construction of the transportation project and its effect on the economic vitality of the community.  Contact the HQ NEPA Specialist for assistance.

  • 6-Step Economic Effects Analysis process (pdf 89 kb).


Hydrology, Floodplains and Groundwater

Guidance for environmental assessment of projects that impact flood plains and groundwater is found in chapters 432 and 433 of the environmental Manual.  For technical assistance for highway and bridge design, flood control, stream bank protection, reach assessment and emergency response, contact the HQ Hydrology Program Manager.


NEPA requires disclosure of the general topographic and geologic setting, significant geologic features, soil types and their properties and known geologic hazards within the project area.  Policy guidance is provided in chapter 420 of the Environmental Manual.  Contact the HQ NEPA Specialist for assistance.


Discipline Report Guidance

Whenever possible document environmental impacts by writing directly to the environmental document (e.g. the EA or EIS).  Include supporting analysis in the appendix.  In rare cases, the subject may be so complex and the supporting analysis so lengthy that a separate discipline report is warranted.  The following documents will help you determine when and how to write quality discipline reports.   

The discipline report checklists are intended to provide general guidance for report reviewers.  The reports should be scaled to reflect the complexity of the project.  Use professional judgment to determine which elements listed are needed for your project. 

Discipline Report Checklists:

Air Quality (pdf 52 kb) Relocation (pdf 44 kb)
Cultural Resources (pdf 40 kb) Section 4(f) (pdf 57 kb)
Economic Elements(pdf 43 kb) Section 6(f) (pdf 35 kb)
Environmental Justice (pdf 42 kb) Social (pdf 51 kb)
Energy (pdf 43 kb) Traffic Noise (pdf 43 kb)
Farmland Conversion (pdf 35 kb) Transportation (pdf 43 kb)
Fisheries Resources (pdf 60 kb) Vegetation (pdf 55 kb)
Floodplain (pdf 41 kb) Visual Impacts (pdf 57 kb)
Geology and Soils (pdf 40 kb) Surface Water (pdf 56 kb)
Groundwater (pdf 40 kb) Wetlands (pdf 50 kb)
Hazardous Materials Wildlife (pdf 59 kb)
Land Use (pdf 59 kb)

Discipline Report Templates:

Economic Effects template (pdf 53 kb)  
Environmental Justice template (pdf 56 kb)  
Fisheries Resources template (pdf 421 kb)  
Social Effects template (pdf 53 kb)  
Vegetation template (pdf 47 kb)  
Wildlife template (pdf 79 kb)  
Surface Water technical guidance (pdf 98 kb)