A quick overview  


Environmental project review encompasses a few common types of documentation. Here’s what you’re likely to find:

Negative Declarations and Mitigated Negative Declarations A Negative Declaration (Neg Dec or ND) is prepared by the lead agency when they believe the project will have no significant environmental impacts. Similarly, the lead agency prepares a Mitigated Negative Declaration (MND) if additional revisions and mitigations would result in the project having either no impact or a less than significant environmental impact. 

The Environmental Impact Report (EIR) is a central component of the CEQA process. It is where the bulk of the environmental review is discussed, analyzing potential impacts, outlining mitigation measures, and discussing the important aspects of the project. The EIR also outlines potential mitigation for those impacts and several alternatives to the proposed project plan (including a “no action” alternative, which assesses the environmental impacts of not having any project).

Types of EIRs

Different types of EIRs and supplementary information are used according to need. Select from the following to learn more.

Project EIR

Aproject EIR is the most common type of EIR required under CEQA. The project EIR is prepared when there is a specific “project” to be evaluated. CEQA defines a “project” as the whole of an action with the potential for either a direct physical change in the environment, or a reasonably foreseeable indirect physical change. A project EIR analyzes each step of the project to outline the complete environmental effects it might have. The project EIR also outlines alternatives to the proposed projects and discusses their potential environmental impacts.

The project EIR undergoes the public review process before the final EIR can be produced and certified, making way for the project to be approved. 

Key distinctions  

  • The Project EIR is focused on a discrete project, and thus conservation efforts on a Project EIR are tied to the single project. 
  • Environmental advocates will generally interact with the Project EIR when they are focused on the impacts of specific projects.
  • A project is defined as an action, which “has a potential for resulting in either a direct physical change in the environment, or a reasonably foreseeable indirect physical change in the environment,” and it involves CEQA when a public agency either enacts it, supports it, or has authority over it.


The Fountain Wind Project, in Shasta County, is an example of a project using a Project EIR. The project is a discrete project, that will construct and maintain wind turbines and their compatible infrastructure. Shasta County, the Lead Agency, prepared a project EIR, given the fact that it is a discrete project. 

Program EIR

A program EIR (PEIR) is prepared when there is a series of related actions, multiple similar projects, or a project with multiple phases, generally involving the issuance of rules, regulations, and other planning criteria. It is usually bound geographically, such as by county and are often used for general plans or multi-phase projects. If a new project is not entirely considered in the scope of the PEIR, a new Initial Study, and its subsequent reports, must be prepared. The new documents can “tier” from the PEIR, referencing areas like the environmental setting and cumulative impacts, therein reducing the need for paperwork and redundancy.  

A PEIR will have comment periods similar to standard EIRs. A draft PEIR will be published for public comment, followed by the publication of a final PEIR and another round of public comment. If a person or group believes that the PEIR was approved improperly, they can sue for violations of CEQA. If smaller projects tiered off of a PEIR will not have environmental impacts, the smaller projects can proceed without additional CEQA review. If the smaller project will have effects that were not analyzed in the PEIR, additional CEQA review is required, often in the form of a subsequent or supplemental EIR.  

Key distinctions 

  • Conservation advocacy on PEIRs take a long-term approach, influencing present and future project developments. 
  • A PEIR allows the lead agency to consider cumulative impacts and mitigation strategies at a policy level early on, ensuring that these are not missed when judged on a case-by-case basis 
  • When a project uses a PEIR without developing an Initial Study or a project EIR, the PEIR must sufficiently address all of the project’s potential environmental impacts. Any activity must be considered fully within the scope of the full PEIR
  • The agency should use a written checklist to evaluate the site and the activity to determine whether the environmental effects are within the scope of the PEIR, if the later activity involves site specific operations 
  • When preparing subsequent EIRs and other new environmental documents, the PEIR can be used as an Initial Study or for reference. 


The City of Watsonville prepared a program EIR for the phased development project titled the Sunshine Vista Phased Development Project. This project consists of two phases of development: the site cleanup and the residential development. It is considered a phased project, and thus the City prepared a program EIR, which outlines the impacts of both phases of the projects. 

The California Vegetation Treatment Program (CalVTP) is a prime example of a statewide, far-reaching project that was approved with a PEIR. The CalVTP is a program designed to address California’s wildfire crisis through implementation of various treatments (prescribed fire, mechanical treatments, etc.) across 500,000 acres of land annually. The California Board of Forestry and Fire Protection, the lead agency in charge of approving the CalVTP, prepared the PEIR to evaluate the environmental impacts of the program as mandated by CEQA. 

Project proponents can use the VTP PEIR for CEQA compliance for their individual fuel management projects. Site-specific environmental analyses for the individual VTP projects are completed as Project Specific Analyses (PSAs). There is no public comment period associated with PSA, and as long as the project is within the scope of the PEIR, meaning the proposed treatments and their impacts were covered in the PEIR, no additional CEQA documentation or environmental review is needed. 

For more information on the CalVTP, please see the CalVTP overview document. 

Subsequent EIR

The lead agency is required to produce a subsequent EIR, after the EIR has been certified or a Notice of Determination (ND) has been adopted if there is substantial evidence that the project will change, resulting in new environmental impacts, the context around the project is substantially changed, or there is critical new information that has just come to light. As a result, the subsequent EIR is only required when the first EIR or ND is no longer sufficient due to changes or new information.  

Key distinctions 

  • The subsequent EIR is only required in light of significant changes or new information. 
  • The subsequent EIR is produced by the lead agency and given the same public review process as a project EIR, providing another opportunity for public engagement with the new information. 


The City of Santa Rosa prepared a Subsequent EIR for the Santa Rosa Downtown Station Area Specific Plan (DSASP) Update. This project was an update to a previously certified EIR for a specific plan. The project required a subsequent EIR because of the changes that occurred in the city during the 12 years since its original certification. The subsequent EIR allows Santa Rosa to update the EIR to more accurately reflect the current state of the city in crafting an updated specific plan. 

Supplement to an EIR

A supplement to an EIR can be prepared instead of a subsequent EIR when changes require only minor additions to make the EIR sufficient. The supplemental EIR is seen as a revision of the project EIR. When evaluated by the agency, the project EIR is considered with the supplement to the EIR as a revision for the relevant changes.  

Key distinctions 

  • A supplement to an EIR would only require the essential information and would not have the same amount of information and analysis that an EIR or a subsequent EIR requires.   
  • It is still subject to the same public review process, although only the supplement to the EIR needs to be circulated. 


The city of Elk Grove prepared a supplemental EIR for the Multi-Sport Complex and Southeast Industrial Annexation Area project. The project had minor changes that occurred after initial EIR certification. The project proposed to change an area’s land use designation and to address additional information related to necessary infrastructure improvements. The City of Elk Grove believed that the changes were minor, and that the discussion in the supplemental EIR would make the previous EIR adequate. 

Addendum to an EIR

An Addendum is required when there have been changes to the project, but the changes do not meet the conditions necessary to trigger a subsequent or supplemental EIR. It is only used for minor technical changes or additions to the adopted EIR or ND that would not significantly alter any of the project’s impacts.  

Key distinctions 

  • An Addendum is only used for minor technical changes or additions to the adopted EIR. 
  • The Addendum does not require circulation for public review; it is attached to the original EIR. 
  • It includes a brief explanation of why the lead agency did not prepare a subsequent EIR, if not included elsewhere in the EIR. 


The County of Los Angeles prepared an Addendum to the Certified Los Angeles County General Plan Update Final Environmental Impact Report to include the Inclusionary Housing Ordinance. The county claimed that the addition of the Inclusionary Housing Ordinance (IHO), which ensures production of affordable units in new development by establishing affordable housing set-aside requirements on residential projects, only required an Addendum. The county claims that the IHO does not create new significant environmental impacts, does not substantially increase the severity of previously identified significant effects, and does not include mitigation measures or alternatives previously found infeasible and now feasible. 

Multiple and phased projects

The lead agency must prepare a single program EIR when a project has multiple parts or phases that will create one ultimate project. When a project is the first step of a larger project or commits the agency to a larger project, the EIR that is prepared must address the scope of the larger project. For multiple similar projects of a public agency that are not part of a larger undertaking or project, the EIR can be prepared for the larger project or it can be prepared for each individual project, while still addressing cumulative effects. 

Key distinctions 

  • When actions are part of a larger project or undertaking, they require a program EIR.
  • If the project EIR focuses on one project that commits an agency to future projects or is the first step of a project, the EIR must address the scope of the larger project. 
  • For similar projects undertaken by an agency, the agency can prepare one EIR for all projects, or individual EIRs, but must address cumulative impacts 


The City of Watsonville prepared a program EIR for the phased development project titled the Sunshine Vista Phased Development Project. This project consists of two phases of development: the site cleanup and the residential development. It is considered a phased project, and thus the City prepared a program EIR, which outlines the impacts of both phases of the projects. 

EIR as part of a General Plan

In certain cases, a General Plan can be used in the place of an EIR. The General Plan must address all the requirements of the EIR and must contain a section or sheet that describes where each requirement of the EIR is addressed. The EIR can also be prepared separately from the General Plan, in which case it follows the requirements of a program EIR and is attached to the General Plan. 

Key distinctions 

  • The General Plan does not require a separate EIR. 
  • If the EIR is prepared separately, the General Plan would be accompanied by a program EIR.  
  • The EIR requirements can be met within the General Plan documents, as long as it includes a section on where to find the information that the EIR requires. 
  • Where a General Plan does use an EIR, a program EIR or master EIR is sufficient. 


The City of Milpitas prepared a program EIR for use with their General Plan in the Milpitas General Plan Update. Using a program EIR is sufficient for the general plan update to comply with CEQA. In this case the City of Milpitas produced the program EIR for their general plan update as a separate document, and did not choose to use the singular general plan document to fulfill the requirements of CEQA. If they had only prepared the single document, it would need to include a cover sheet or section that clearly states where the EIR information could be found in the general plan update. 

Staged EIR

A staged EIR is used when there is a large project that will require multiple approvals from government agencies. The staged EIR evaluates the project given the current information and estimates the potential future impacts of the project. It gives great detail about the stage of the project that is up for approval and will provide a supplement to the EIR for each following stage of the project when it is up for approval. 

Key distinctions 

  • The staged EIR is obsolete, as a program EIR would generally be used in its place. 
  • The staged EIR may be used when a project requires several discretionary approvals from government agencies, where an approval will occur two years before construction begins. 
  • A main purpose of the staged EIR is to allow for an agency to begin the environmental review process for a staged project, even years before the typical Lead Agency (such as a county) will interact with the project. As a result, the staged EIR will only have the essential information for the current approval and will note the larger scope of the project. 
  • A staged EIR may be used when there are multiple stages to a large project, requiring approvals at different times throughout the project. 
  • A supplement to the staged EIR is required for each of the later stages of the project, providing deeper analysis of the stage up for approval. 


A joint EIR-EIS (Environmental Impact Statement) is appropriate when CEQA and NEPA are both triggered on a project. The joint document must meet the requirements of both CEQA and NEPA. The major distinction in the NEPA and CEQA process is in the handling of “significant” impacts. NEPA requires an EIS when the project as a whole has the potential to “significantly affect the quality of the human environment.” For an EIS, it is the magnitude of the impact that is evaluated and no judgment of its significance is needed. CEQA, on the other hand, requires identification of each “significant effect on the environment” and a mitigation strategy for each impact, if feasible.

Key distinctions 

  • Projects that involve one or more state or local agencies and one or more federal agencies should use a joint EIR/EIS.  
  • “Significance” is handled differently for NEPA and CEQA, where NEPA is concerned with the significance of the project as a whole, and CEQA is concerned with each significant impact of the project 
  • Only one review and comment period is required, so if a federal agency has circulated a EIS or a Finding of No Significant Impact, the lead agency need not recirculate. However, it is still required to notify the public that it will be using the NEPA documents in place of EIR/Notice of Determination. 
  • State and local agencies should cooperate with federal agencies as much as possible with each phase, including areas like environmental research, public review, and document development.


The California High-Speed Rail Authority prepared a joint EIR/EIS for the California High-Speed Rail Bakersfield to Palmdale Project. The project required an EIR under CEQA, as the high speed rail project falls under the jurisdiction of several public agencies in the state and will impact the environment significantly. The project also required an EIS under NEPA because all railroad projects in the U.S. fall under the jurisdiction of the Federal Railroad Administration. The lead agency under NEPA and the lead agency under CEQA came to an agreement to produce the joint EIR/EIS together.  

Master EIR

Amaster EIR is used to form the basis of long-term decision making, streamlining later environmental review. It is commonly used with general plans and is an alternative to project, staged, and program EIRs. The master EIR takes into account the cumulative effects and potential future impacts as feasible. 

Key distinctions 

  • The master EIR is mostly obsolete, as a program EIR would generally be used in its place. 
  • It evaluates the cumulative impacts, growth inducing impacts, and irreversible significant effects of all subsequent projects. 
  • An alternative to project, staged, and program EIR, it is intended for streamlining of later environmental review.  
  • A focused EIR or ND/MND is prepared for subsequent actions outside of the scope of the master EIR 


The City of Modesto prepared a master EIR to examine the potential environmental effects of the City of Modesto Urban Area General Plan. The general plan is a long range planning document, for which a master EIR fulfills the requirement and can be used to analyze cumulative impacts, growth impacts, and impacts of subsequent projects. An initial study will be conducted to ensure that subsequent actions are in the scope of the master EIR. 

Focused EIR

A focused EIR is used when a subsequent project identified in a master EIR may have significant effects on the environment or where substantial new or additional information shows that the adverse environmental impact may be more significant than was described in the master environmental impact report. A focused EIR on any subsequent project only needs to analyze the impacts that may be more significant than described in the master EIR and should include new or additional mitigation measures or alternatives not identified and analyzed in the master EIR.  

Errata to an EIR

An errata is a document typically used to document changes to the final EIR. They usually only include minor technical corrections or clarifications, and do not usually result in any new significant impacts that would require a recirculation of documents. 

Key distinctions 

  • Erratas should only be used when there are minor changes or updates to the final EIR document 
  • They do not require a recirculation of documents. 
  • If the errata includes new significant impacts, the errata is not sufficient documentatoin, and the changes should have triggered a recirculation of environmental documents 


The City of Los Angeles prepared an errata to a final EIR for the Hollywood and Gower Project. The errata contained only minor updates and clarifications, including design refinements and corrections to numbers. The City of Los Angeles found that the errata would not disclose a new significant environmental impact or mention a substantial increase in the severity of an environmental impact. Therefore, an errata to the EIR was sufficient, and no recirculation of documents was required.