​SEPA Review and Commenting Guidance

When a proposal is under environmental review, the public, community and business groups, local and tribal governments, state agencies, and other entities with expertise can review and comment on SEPA documents. 

Guide to commenting on SEPA documents

Under the State Environmental Policy Act (SEPA), reviewers have the opportunity to examine the environmental analysis done for a proposal and weigh in before agencies make any final permitting decisions.

During the review period, the general focus will be determining whether the SEPA documents address the following questions:

  • Are the SEPA documents complete and accurate?
  • Do they provide enough information to analyze likely environmental impacts?
  • Do they identify mitigation measures to avoid adverse impacts?
  • Is the evaluation and Determination of Significance supported by findings and conclusions?
  • Are there alternatives that address the proposal’s purpose and need?

General tips

  • Be respectful
  • Make your comments easy to read
  • Include the lead agency’s file number for the proposal
  • Start with general comments, followed by specific, page-by-page comments
  • If your comments are extensive, include a summary at the beginning of your letter
  • Use headings and / or topic sentences
  • Suggest specific language changes or additions
  • Make declaratory statements supported with facts
  • Identify the things you support
  • Provide specific examples illustrating your concerns
  • Offer helpful solutions
  • Provide information about how and where to locate more information or guidance
  • Provide your contact information at the end of your comments
  • Avoid or limit asking questions and use “if-then” statements instead, such as:
    • Do say: “If this project will include the use of generators, then . . .
    • Don’t say: “It is unclear whether the proposal will include the use of generators.

Critical importance of commenting on SEPA documents 

It is more effective to comment during SEPA review than waiting until the permitting process starts. This will help the applicant and lead SEPA agency develop a more environmentally-sound project. Reviewing and commenting on SEPA documents provides the opportunity to:

  • Identify and resolve concerns early in the review process.
  • Identify required permits, applicable regulations, and permit conditions likely to be required.

Failure to comment during the SEPA process can limit future comments as well as an agency's ability to appeal a proposal, or use SEPA supplemental authority to condition or deny a permit based environmental impacts. 
Although some lead agencies consider late comments, most will not. Every effort should be made to submit comments while the comment period is open to help:

  • Identify and provide missing or incomplete information
  • Raise concerns about an environmental analysis and / or methods used to develop the analysis
  • Create a record
  • Identify possible solutions, including mitigation measures
  • Identify needed permits or other approvals
When reviewers identify missing information or studies needed to help agencies analyze a project, it is important this be conveyed to the lead SEPA agency before a threshold determination is made. It helps to send copies of comment letters to the applicant, other agencies with jurisdiction, and others interested in a proposal. 

Commenting on nonproject actions

Nonproject actions often include plans for future on-the-ground projects   including needed regulations. Reviewing a nonproject SEPA document provides an opportunity to:
  • Affect many future projects
  • Address cumulative impacts
  • Identify possible mitigation for future projects to reduce or eliminate environmental impacts
  • Ensure an adequate alternatives analysis meeting the objectives of the proposal is completed
Since a nonproject action will regulate future activities, it is important to consider the types of allowable projects and their likely impacts. Identifying concerns or possible mitigation measures at the nonproject stage allows them to be considered before a policy, plan, or regulation is adopted. Some aspects, however, such as land-use designations and residential development density, may not be reconsidered when a proposed project meets a lead agency's planning or zoning requirements.

Commenting on Environmental Impact Statements

The scoping notice allows early involvement during the environmental analysis of a proposal. Concerns identified during during the scoping process can be further evaluated when a draft Environmental Impact Statement (EIS) is being prepared. It's usually easier and more effective to comment during the scoping process than wait until  the analysis of a draft EIS. Consider:


  • Is the proposal clearly described? 
  • Is a purpose and need statement included?
  • Is the proposal properly defined, including its related or interdependent parts?

EIS elements

  • Does the scoping notice identify all the environmental elements that will be significantly impacted and addressed in the EIS?


  • Is a range of alternatives included? 
  • Are there other alternatives that meet the proposal’s objective that should be considered?

Environmental impacts

  • Are there specific issues needing to be addressed?
  • Have they been identified in the scoping notice?
Your letter should provide as much possible information to help the lead agency define the “scope” of the EIS. The more detailed your comments, the more likely that the issues will be adequately evaluated in the draft EIS including:
  • Environmental elements be evaluated
  • Any needed studies and analyses
  • Alternatives to be considered
A draft EIS should include an impartial discussion about the total proposal, alternatives, significant impacts, and mitigation measures. A draft EIS without comment effectively concurs a lead agency's analysis is correct. 

When a permit issue has been raised and the lead SEPA agency fails to respond to comments in the draft EIS, reviewers can prepare a supplemental EIS to evaluate probable environmental impacts that have not been adequately addressed. Questions to consider:
  • Is the proposal properly defined, including any related or interdependent parts?
  • Have probable, significant adverse environmental impacts been identified and evaluated?
  • Does the EIS evaluate a range of reasonable alternatives?
  • Are possible mitigation measures identified? 
  • Are there other mitigation measures that should be considered?
  • Does the EIS identify any significant adverse environmental impacts that cannot avoided or reasonably offset through mitigation?