1. Home
  2. Programs
  3. Environmental Analysis
  4. Standard Environmental Reference (SER)
  5. Volume 1: Guidance for Compliance
  6. Chapter 31 - Environmental Assessment (EA)/Finding of No Significant Impact (FONSI)

Chapter 31 - Environmental Assessment (EA)/Finding of No Significant Impact (FONSI)

Note: If You Are Preparing A Joint CEQA/NEPA Document - See Chapter 37

What Does This Topic Include?

This chapter discusses the preparation and processing of a NEPA Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) and may be most applicable to Local Assistance projects subject to NEPA but for which CEQA compliance is done separately. For guidance on joint CEQA/NEPA Documents refer to Chapter 37. For guidance on CEQA Initial Studies and Negative Declarations, refer to Chapter 35.

Environmental Assessment Decision Tree

View the NEPA Process Overview for FHWA or Caltrans Actions (PDF)

Laws, Regulations and Guidance

See the SER Chapter 1–Federal Requirements for the complete list of Federal requirements

Policy Memos

Revisions to the Council on Environmental Quality Regulations

On July 16th, 2020, the Council on Environmental Quality (CEQ) published in the Federal Register the Final Rule to update its regulations for the implementation of the National Environmental Policy Act (NEPA). The updates are effective for all NEPA reviews begun after September 14, 2020. For reviews that began prior to September 14, 2020, agencies may decide to apply the revised regulations or proceed under the 1978 regulations. An EIS or EA should clearly indicate which procedures will be applied for each proposed action.

The regulations require that each federal agency develop or revise, as necessary, its proposed procedures to implement CEQ’s updated NEPA regulations. As such, it is anticipated that the Federal Highway Administration (FHWA) will be issuing revisions to its implementing NEPA regulations found in Title 23, Code of Federal Regulations, Part 771 (23 CFR 771). This update will be subject to the federal rulemaking process. FHWA’s current NEPA regulations will remain in effect until that time. In the event that there is a conflict between CEQ’s NEPA regulations and the existing FHWA regulations, the CEQ regulations shall apply, unless there is a clear and fundamental conflict with the requirements of another statute.

23 USC 139 Efficient Environmental Review Process

The "Efficient Environmental Review process" established by SAFETEA-LU in 2005 (and codified at 23 USC 139) and retained and revised by MAP-21 in 2012 and the FAST Act in 2015, applies to EISs but, at the discretion of the Caltrans Deputy District Director for environmental, may be applied to EAs on a case-by-case basis. The 23 USC 139 procedures are described in Chapter 32 and involve additional public and agency participation.

Definition and Purpose of an Environmental Assessment

Federal Highway Administration (FHWA) NEPA regulations distinguishes three classes of actions which prescribe the level of documentation that is required in the NEPA process (23 CFR 771.115). Class I actions are actions that significantly affect the environment and normally require the preparation of an EIS (see Chapter 32). Class II actions are those that do not individually or cumulatively have a significant effect and are categorically excluded from NEPA (see Chapter 30). Class III actions are those in which the significance of the environmental impacts is not clearly established. All actions in this class require the preparation of an Environmental Assessment (EA).

The purpose of an EA is to determine if a project will cause significant effects necessitating the preparation of an Environmental Impact Statement (EIS). If the assessment concludes that an EIS is required, the information contained in the EA facilitates its preparation. If an EIS is then initiated, refer to Chapter 32. If the EA concludes that no significant impacts will occur, a Finding of No Significant Impact (FONSI) is prepared. The EA supports Caltrans’ conclusions when adopting a FONSI and documents NEPA compliance. The revised CEQ regulations also specifically allow for the preparation of an EA when a project is not likely to have significant effects but is not categorically excluded (40 CFR 1501.5).

Under Caltrans’ implementation of 23 USC 327, EAs have been divided into two categories: complex EAs and routine EAs. Complex EAs are defined as those EAs that have complex issues or impacts in that they may include multiple location alternatives, debate related to purpose and need, strong public controversy, issues related to logical termini or independent utility, individual Section 4(f) determinations, complex Endangered Species Act issues, numerous cumulative impacts or high mitigation costs. Routine EAs are prepared, reviewed and approved entirely within the district/region. Complex EAs undergo a more stringent review process identical in virtually every way to the EIS review. The decision regarding whether the action call for a complex EA or a routine EA is made in consultation with Caltrans as outlined in the SER, Volume 1, Chapter 38, NEPA Assignment—Class of Action Determination. Obtaining the concurrence of the HQ District Environmental Coordinator can be done via an e-mail stating the project description, proposed class of action, and rationale.

The revised CEQ regulations also strengthened the existing page limits for an EA by requiring the written approval of a senior agency official in order to exceed 75 pages and established a one-year time limit for the completion of an EA unless a longer time period is approved in writing by a senior agency official.  The one-year time limit is measured from the date of the agency decision to prepare an EA to the publication of an EA or FONSI.

State Compliance Considerations

The majority of Caltrans projects involve compliance with both NEPA and CEQA and other federal and state environmental laws. When both NEPA and CEQA apply, it is generally preferable to prepare a joint NEPA/CEQA document that satisfies both requirements (See Chapter 37). Even when circumstances dictate the preparation of separate federal and state environmental documents, it is good practice to take both processes into consideration when consulting with the relevant federal and state agencies, providing for public participation and determining the need for special studies and permits. Planning and coordination that considers both federal and state requirements avoids duplication of effort and unnecessary delay and cost.

Early Consultation

There is no formal scoping requirement for an EA. However, the Council on Environmental Quality (CEQ) regulations mandate that federal agencies involve the public, state, tribal, and local governments, relevant agencies, and any applicants, to the extent practicable in the EA process [40 CFR 1501.5]. Informal consultation is important in defining purpose and need, environmental impacts, determining alternatives and mitigation, establishing permit requirements and anticipating issues or concerns to both state and federal agencies which may affect the project design, cost and scheduling.

The identification of cooperating agencies begins at the Programming Stage. Background research and preliminary site survey establishes potential environmental constraints and identifies various governmental agencies with interest or expertise relevant to the project. This information is included in the Preliminary Environmental Assessment Report (PEAR), or for Local Assistance projects, the Preliminary Environmental Study (PES) form. At the beginning of the environmental process, technical study requirements are refined and formal consultation with state and federal agencies is undertaken.

To implement coordination at the start of the environmental process cooperating agencies are sent letters inviting them to participate in the development of the environmental document. Cooperating agencies, such as U.S. Army Corps of Engineers, or U.S. Fish and Wildlife Service, are invited in writing to participate in early meetings to discuss issues and permits that may be involved in the project. Tribal governments should also be involved in early coordination and can be cooperating agencies. Copies of early coordination letters are included in the appendices of the EA. Meetings and substantive contacts with agencies are also documented. For more information on coordination in the early project development phases see Chapter 5 "Preliminary Scoping." For projects off the State Highway System additional information on coordination with resource and regulatory agencies is discussed in the Local Assistance Procedures Manual (LAPM), Chapter 6.

Public Participation

NEPA encourages public participation. However, because there is no formal scoping requirement for an EA, the degree of public participation and the means of soliciting public input are determined on a case specific basis, taking into consideration the results of public participation efforts at the planning and programming stages and the degree of public interest or controversy [23 CFR 771.119(b)]. Where there is potential for public controversy informal environmental scoping may be of value in defining environmental impacts, alternatives, and issues of concern to the community. Executive Order 11990 section 2(b) specifically requires opportunity for early public review of an EA where the proposed action involves new construction in a wetland and Executive Order 11988 similarly requires public review of EAs for plans or actions in floodplains. Additionally, Section 106 of the National Historic Preservation Act requires public participation in the identification and evaluation of historic resources, even if no historic properties are found within the Area of Potential Effect (APE). For additional information on public participation requirements of Section 106 and the Caltrans Section 106 Programmatic Agreement (PA), see the SER, Volume 2, Cultural Resources.

For further discussion of the public participation process under NEPA see Chapter 3. Guidance regarding public notice requirements and carrying out public involvement is found in Project Development Procedures Manual, Chapter 11. See also the joint FHWA/FTA publication Public Involvement Techniques for Transportation Decision-Making (June 2015).

Preparing an Environmental Assessment

The CEQ NEPA guidance encourages conciseness in EA documents (Forty Most Asked Questions Concerning CEQ's NEPA Regulations). An EA need only address those issues that Caltrans has determined have a potential for significant impact. The EA should briefly discuss the purpose and need for the proposed project, the alternatives considered, the environmental effects of the proposed project and alternatives, and include a list of agencies and persons consulted (40 CFR 1501.5). Technical information and studies developed to analyze impacts are summarized in the document and/or incorporated by reference. Technical studies that support the EA are a part of the environmental compliance record and are public documents. For more information on alternatives development for an EA, please see the Alternatives Analysis Frequently Asked Questions.

Caltrans has developed annotated outlines for joint CEQA/NEPA documents including joint IS/EAs and joint EIR/EAs and a NEPA-only EA annotated outline.  The outlines are available on the SER Forms and Templates webpage. The format contained in these outlines is mandatory for Caltrans projects and for Local Assistance projects, use of the NEPA-only annotated outlines at minimum is mandated. Local agencies are strongly encouraged to use the joint NEPA/CEQA outlines whenever possible. Use of the annotated outlines ensures a document that meets FHWA and Caltrans standards and facilitates project review and electronic publishing.

Detailed technical information and/or technical reports should be treated as appendices to the EA, but should be bound as separate documents and referenced in the EA. The appendices should include only analytical information that substantiates analysis that is important to the document (e.g., a biological assessment for threatened or endangered species). Separate technical reports need not be circulated during public review, however, they are public documents and must be available for public review at specified locations (see below).

Section 4(f) Evaluation

If the EA includes a Section 4(f) evaluation, or if such an evaluation has been prepared separately, it must be circulated to the appropriate agencies. Requirements for coordination of Section 4(f) documents is provided in 23 CFR 774. Guidance on Section 4(f) is provided in Chapter 20.

Internal Review and Administrative Approval Processing

Caltrans has an environmental quality control program under NEPA Assignment. Under Caltrans’ implementation of 23 USC 327, EAs have been divided into two categories: complex EAs and routine EAs. Complex EAs are defined as those EAs that have complex issues or impacts in that they may include multiple location alternatives, debate related to purpose and need, strong public controversy, issues related to logical termini or independent utility, Individual Section 4(f) determinations, complex Endangered Species Act issues, numerous cumulative impacts or high mitigation costs. Routine EAs are prepared, reviewed and approved entirely within the district/region. Complex EAs undergo a more stringent review process identical in virtually every way to the EIS review. The decision regarding whether the action call for a complex EA or a routine EA is made in consultation with Caltrans as outlined above and as found in the Class of Action Determination section of Chapter 38. Obtaining the concurrence of the HQ District Environmental Coordinator can be done via an e-mail stating the project description, proposed class of action, and rationale.

An important aspect of the quality control program is the NEPA Quality Control Review. The purpose of this review component is to ensure that the environmental document complies with FHWA policies and guidance and the requirements of all applicable federal laws, executive orders, and regulations. For additional information regarding, the quality control program, please see the policy memo on Changes to Environmental Document Quality Control Review Procedures and Forms and the Integrated Quality Control/Quality Assurance Review Procedures section of Chapter 38 for full details.

The Complex EA review and approval procedures to comply with NEPA Assignment requirements must be followed before the document can be signed and approved. Please see SER, Volume 1, Chapter 38 for detailed information regarding signature authority for EAs. For routine EAs, the quality control program must be followed and the Internal Quality Certification completed before the document can be signed and approved.

For additional information on the processing and internal review of EA documents for projects off the State Highway System consult the Local Assistance Procedures Manual (LAPM), Chapter 6, Section 6.8.

Public Review and Comment Draft EA

Federal regulations do not require the circulation of the draft EA for public comment. However, in practice, Caltrans circulates the draft EA to other public agencies for comments. A Notice of Availability (NOA) and copies of the draft document should be sent to all cooperating and participating agencies. If the project requires an individual Section 404 permit, a copy of the Draft EA should be provided to the Army Corps of Engineers, U.S. Fish and Wildlife Service, U.S. EPA, and NOAA Fisheries. Copies should also be sent to any groups or individuals who have requested the document. The NOA and draft EA are submitted to the State Clearinghouse, Governor’s Office of Planning and Research (OPR) along with a Notice of Completion (NOC) and OPR Summary Form via CEQA Submit. Please see the State Clearinghouse CEQA Document Submission website for full instructions, forms, and a link to the CEQA Submit Database.

The document and supporting studies also must be available for public inspection at the appropriate Caltrans district office. Technical studies are not distributed to the Clearinghouse.  Additionally, the revised CEQ regulations require 1) that agencies provide for a website or other means to make environmental documents, relevant notices, and other relevant information available to other agencies, applicants, and interested persons. Caltrans should also provide for the electronic submission of public comments on EAs.

Public hearings are encouraged, but not required, under NEPA. However, FHWA regulations and the Project Development Procedures Manual (PDPM) require a public hearing for any projects that:

  1. Require significant right of way
  2. Require substantial changes to the layout, or to the function of connecting roadways, or facility being improved,
  3. Have a significant adverse impact on abutting real property, or
  4. Have a significant environmental, economic, social, or other effect.

A "Notice of Opportunity" for a public hearing may be used to satisfy the requirement for a hearing if the project is non-controversial and a hearing request is unlikely. This can be determined by analysis of comments received from the public or local agencies or through prior contacts and information meetings.

Note that a public hearing is required for any Interstate System project or Federal-aid highway project involving the bypassing of or, going through any city, town, village, either incorporated or unincorporated (23 USC 128).

Chapter 11, Article 7 of the PDPM includes a discussion of how to plan, prepare and conduct a public hearing.

When a public hearing is held, the EA shall be available at the public hearing and for a minimum of 15 days in advance of the public hearing. The notice of the public hearing in local newspapers must announce the availability of the EA, where it may be obtained or reviewed, as well as information on how and where to submit comments. Comments must be submitted in writing within 30 days of the availability of the EA unless Caltrans determines, for good cause, that a different period is warranted. Public hearing requirements are described in 23 CFR 771.111 and the SER, Chapter 3. See the PDPM Chapter 11 for additional information regarding types of public hearings and alternative meeting formats, such as open houses or map showings.

When a public hearing is not held, the district or the local agency must place a notice in a newspaper(s) similar to a public hearing notice and at a similar stage of development of the action, advising the public of the availability of the EA and where information concerning the action may be obtained. The notice invites comments from all interested parties. Comments must be submitted in writing within 30 days of the publication unless Caltrans determines otherwise.

If the project will affect cultural resources, the public notices announcing scoping meetings or announcing the availability of the EA must include the following statement: “The proposed work may have an effect on historic properties eligible for the National Register of Historic Places. Caltrans is evaluating alternatives to determine if the project can avoid adversely affecting the property(ies) or, if not, if adequate mitigation measures can be incorporated into the project plans.”

The filing of the notice and documents with the State Clearinghouse, the notification of cooperating and participating agencies, and the public notice published in the newspaper satisfy the requirements of Executive Order 12372 regarding intergovernmental review of federal programs.

When the EA indicates that the project has the potential to result in a significant impact, an EIS must be prepared. An EA is not required when a decision has already been made to prepare an EIS. At the conclusion of the public availability period, the EA should be finalized by being revised or an attachment provided, as appropriate, to (a) reflect changes in the proposed action or mitigation measures resulting from comments received or from the public hearing, if one was held, and (b) include any necessary findings, agreements, or determinations required for the proposal. A copy of the comments and responses should be attached to the revised EA.

If no significant impacts are identified and the EA is routine, the FONSI is prepared and sent to the appropriate Caltrans authority for signature. If the document is a complex EA, the FONSI is prepared and sent to the HQ District Environmental Coordinator for concurrence and then to the appropriate district/region authority for signature (see the Step-by-Step Procedures in Chapter 38 for detailed instructions).

As a courtesy, provide a copy of the "draft" EA (routine and complex) to the Headquarters NEPA Assignment Office.

For additional information, see the Quick Guide to Public Noticing and Filing Requirements under CEQA and NEPA.

Final EA and FONSI:

A FONSI is a public decision document that briefly describes why the project will not have any significant environmental effect and will not require the preparation of an EIS.

The FONSI must document the reasons for deciding that the action will not have a significant effect on the environment. If relevant it must show which factors were weighted most heavily in the determination. It should also incorporate by reference any other environmental documents used to support the assessment. The FONSI must also state the authority for any mitigation that Caltrans has adopted and any monitoring or enforcement provisions. If Caltrans finds no significant impacts based on mitigation, the FONSI must state any enforceable mitigation requirements or commitments that will be undertaken to avoid significant impacts (40 CFR 1501.6). The FONSI is usually a one-page document to which the EA is attached or referenced. A sample FONSI can be found on the SER Forms and Templates page.

Public Review FONSI and Final EA

Formal distribution of a FONSI is not required. However, an EA, at a legal minimum, must be made available for public review upon request for at least 30 days before making a final determination. FHWA regulations require that a Notice of Availability (NOA) of the FONSI be sent to the affected units of federal, state, and local government and to the State Clearinghouse in compliance with Executive Order 12372. Although the circulation requirements for a FONSI are very limited, send the NOA and a copy of the FONSI and Final EA to cooperating and participating agencies and agencies which commented on the EA or requested to be informed of the project decision.  Additionally, Caltrans should provide for the electronic submission of comments.

As a courtesy, provide a copy of the "final" EA (routine and complex) to the Headquarters NEPA Assignment Office.

Statute of Limitations

SAFETEA-LU Section 6002 established a 180-day statute of limitations (SOL) on claims against USDOT and other federal agencies for certain environmental and other approval actions if certain circumstances apply (23 CFR 771.139). The enactment of MAP-21 revised this to a 150-day statute of limitations. The action must be related to a transportation project and a Statute of Limitations Notice must be published in the Federal Register announcing that a federal agency has taken an action on a transportation project that is final under the federal law pursuant to which the action was taken. Note: Even under NEPA Assignment (23 USC 327), FHWA is still the entity that must publish the Federal Register notice. If a SOL notice is not published in the Federal Register, the normal 6-year period for claims applies. All federal agency decisions, permits, and approvals must be final before the SOL notice can be published. The statute of limitations provision covers all levels of NEPA documentation, although FHWA anticipates that it will be used primarily for EISs and EA/FONSIs but rarely for CEs. FHWA will file the SOL notice in the same manner as it files Notices of Intent. (NOIs and SOL notices are not submitted to EPA for publication in the Federal Register.)

See the FHWA/FTA SAFETEA-LU Environmental Review Process Final Guidance Statute of Limitations and its Appendix E for questions and answers as well as formats to cover various situations.

(Last content update: 02/20/2024, JH)