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DAHP SEPA Review Group

The State Environmental Policy Act (SEPA) provides a way to identify possible environmental impacts that may result from governmental decisions. These decisions may be related to issuing permits for private projects, constructing public facilities, or adopting regulations, policies or plans.

Information provided during the SEPA review process helps agency decision-makers, applicants, and the public understand how a proposal will affect the environment.  This 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.

Who does SEPA review?

Archaeological InvestigationsSEPA applies to decisions made by every state agency, local government, port, and special district (such as a school or water district). One agency is usually identified as the "lead agency" for a specific proposal. The lead agency for most private projects will be the city or county where the project is located. For public projects, the lead agency will be the agency proposing the project. The lead agency is responsible for identifying and evaluating the potential adverse environmental impacts of a proposal. This evaluation is documented and, in most cases, sent to other agencies and the public for their review and comment.

What is the SEPA review process?

SEPA environmental review usually starts when:

  • Someone submits an application to an agency for a license or permit to construct a private project, such as an office building, a grocery store, or an apartment building;
  • An agency is considering construction of a public project, such as a new school, a highway, or a water pipeline; or
  • An agency is developing a regulation, policy, or plan, such as a county or city comprehensive plan, a critical area ordinance, or a state water quality regulation.

Some minor projects do not require environmental review, so the lead agency will first decide if environmental review is needed. If the proposed project is the type of project that has been "categorically exempt" from SEPA review, no further environmental review is needed.

Tiger Store, near Ione - 1912If the proposed project is not exempt, the applicant will usually be asked to fill out an "environmental checklist". This checklist asks questions about the proposal and its potential impacts on a variety of subjects including impacts to historic and cultural resources. "Question 13" on the SEPA checklist relates to archaeological, historical and cultural resources.  The Department of Archaeology & Historic Preservation is considered the agency with expertise in this area.

Under SEPA, resources on the subject or adjacent property, should be evaluated for their eligibility at the local, state and/or national register level.  Typically such evaluations for the built environment will be done at the at the reconnaissance level. FYI..... Note that DAHP will only review eligibility determination for State and National Register listing. Eligibility for local listing is done through a city or county preservation program.  For questions about eligibility, contact Michael Houser, State Architectural Historian (360) 890-2634 or

After the checklist has been completed, the lead agency will review the checklist and other information about the proposal.  If the lead agency needs additional information to evaluate the proposal, they may ask the applicant to conduct studies, such as a traffic study, or a study to determine if there are wetlands on the project site, etc. The lead agency and applicant may also work together to change the proposal to reduce likely impacts.

If the lead agency has enough information to determine that the proposal is unlikely to have a significant adverse environmental impact, the agency will issue a determination of non-significance (DNS). If the information indicates the proposal is likely to have a significant adverse environmental impact, the lead agency will require the preparation of an environmental impact statement (EIS). The EIS will include an evaluation of alternatives to the proposal and measures that would eliminate or reduce the likely environmental impacts of the proposal.

How is SEPA used in decision making?

The DNS or EIS prepared by the lead agency will provide information to all agencies that must approve the proposal. The environmental information will be considered along with technical, economic, and other information about the proposal by agency decision-makers as they decide whether or not to issue a license for the proposal. 

SEPA gives agencies authority to condition a proposal when specific adverse environmental impacts are identified in the DNS or EIS. For example, if an EIS indicates the proposal will damage a wetland, the agency decision-maker may require the applicant to change his proposal so that no construction will be done within one hundred feet of the wetland.

In rare cases, an agency may deny a proposal when an EIS shows that the proposal is likely to have significance adverse environmental impacts that cannot be reduced to an acceptable level.

For Additional Information:

For general SEPA Assistance contact:

Environmental Coordination Section
Department of Ecology
PO Box 47703
Olympia WA 98504-7703
Phone: (360) 407-6922
Fax: (360) 407-6904