If a project has already been analyzed in an EIR or (mitigated) negative declaration but elements of the project or circumstances surrounding it change, subsequent environmental review may be necessary. (See Pub. Resources Code, § 21166.) Subsequent environmental review can take the form of a subsequent or supplemental EIR, a subsequent negative declaration, or an addendum. (CEQA Guidelines, §§ 15162-15164.) Pursuant to section 21166, a subsequent EIR cannot be required unless one of the following occurs:
- Substantial changes are proposed in the project which will require major revisions of the EIR.
- Substantial changes occur with respect to the circumstances under which the project is being undertaken which will require major revisions in the EIR.
- New information, which was not known and could not have been known at the time the EIR was certified as complete, becomes available. (See also CEQA Guidelines, § 15162(a).)
This creates a presumption against requiring a supplemental EIR, which, as explained in more detail below, is in contrast to the presumption in favor of preparing an EIR at the outset of environmental review. (See Martis Camp Community Assn. v. County of Placer (2020) 53 Cal.App.5th 569, 603-604 (Martis Camp); see also Mani Brothers Real Estate Group v. City of Los Angeles (2007) 153 Cal.App.4th 1385, 1398-1399.)
Importance of Section 21166
Section 21166 fulfills the important function of balancing environmental protection against the burdens of compliance and the need for finality. (See Friends of College of San Mateo Gardens v. San Mateo County Community College Dist. (2016) 1 Cal.5th 937, 949 (San Mateo Gardens I); Bowman v. City of Petaluma (1986) 185 Cal.App.3d 1065, 1074 (Bowman).) It accomplishes this by shifting policy considerations and prohibiting further environmental review unless the above stated conditions are met. As initially explained in Bowman, section 21151 creates a “low threshold requirement for preparation of an EIR” at the project’s outset. (Bowman, supra, 185 Cal.App.3d at p. 1073.) In contrast, section 21166 prohibits agencies from requiring a subsequent EIR unless “circumstances have changed enough to justify repeating a substantial portion of the [environmental review] process.” (See ibid. (emphasis original).)
The requirement to undertake subsequent environmental review is only triggered when further discretionary action is required. (CEQA Guidelines, § 15162(c); Willow Glen Trestle Conservancy v. City of San Jose (2020) 49 Cal.App.5th 127, 132-134 [steps to implement previously approved project do not trigger subsequent review]; Fort Mojave Indian Tribe v. Department of Health Services (1995) 38 Cal.App.4th 1574, 1596-1598, 1605 [allegedly new information and changed circumstances arising after project approval do not trigger subsequent environmental review until “the next discretionary approval, if any”].) Additionally, the scope of the potential subsequent environmental review is limited by, and corresponds to, the scope of the subsequent discretionary action. (See San Diego Navy Broadway Complex Coalition v. City of San Diego (2010) 185 Cal.App.4th 924, 938-940 [design review did not open project up to greenhouse gas challenge].) Further, when subsequent environmental review occurs, it does not open the door to revisit environmental issues addressed in the original analysis – only the changed circumstances may be challenged. (San Mateo Gardens I, supra, 1 Cal.5th at pp. 949-950.) This is true “even if the initial review is discovered to have been inaccurate and misleading in the description of a significant effect or the severity of its consequences.” (Friends of Davis v. City of Davis (2000) 83 Cal.App.4th 1004, 1018 (Friends of Davis), citing Laurel Heights Improvement Assn. v. Regents of University of California (1993) 6 Cal.4th 1112, 1130.)
Applying these principles, courts have upheld agencies’ determinations not to require a subsequent EIR in a number of contexts. (E.g., Fund for Envtl. Def. v. County of Orange (1988) 204 Cal.App.3d 1538, 1545-1546, 1550-1552 [SEIR not required where the project increased in size by approximately 30 percent and the surrounding land was designated as a wilderness park following the project’s initial approval]; Fort Mojave Indian Tribe v. Department of Health Services (1995) 38 Cal.App.4th 1574, 1605 [change in legal characterization of project site as “critical habitat” for an endangered species did not trigger SEIR because this did not change the significance of the project’s impacts]; Citizens Against Airport Pollution v. City of San Jose (2014) 227 Cal.App.4th 788, 806-812 (Citizens Against Airport Pollution) [upholding eighth addendum including changes to mitigation measures for impacts on burrowing owls and rejecting argument that an SEIR was required to comply with newly added CEQA Guidelines section 15064.4(a) because analysis of GHG emissions was not required when project EIRs were prepared plus potential impacts from GHG emissions did not constitute new information for purposes of section 21166]; Friends of Davis, supra, 83 Cal.App.4th at pp 1021-1022 [identification of a national chain bookstore as a proposed tenant for a new development did not constitute a “change” requiring an SEIR].) Section 21166 does not, however, allow an agency to escape undertaking environmental review where it intentionally expands the project in a way that that increases impacts beyond those analyzed in the EIR. (See Concerned Citizens of Costa Mesa, Inc. v. 32nd Dist. Agricultural Assn. (1986) 42 Cal.3d 929, 937-938 [amphitheater project violated CEQA because it was substantially changed without public notice or analysis in an SEIR].)
Threshold Issues and Standards of Review
The lead agency has discretion to determine whether the subsequent environmental review provisions apply in the first instance. Plaintiffs in San Mateo Gardens I argued that courts are obligated to determine whether a proposal constitutes a “new” project, such that section 21151, rather than section 21166, applies (thereby pushing the presumption towards preparation of a full EIR). (San Mateo Gardens I, supra, 1 Cal.5th at p. 950.) The Supreme Court rejected such a test as inviting arbitrary results. (Id. at p. 951.) Instead, it held that the lead agency has discretion to determine whether the original environmental document retains some informational value or remains relevant despite the proposed changes or circumstances; this determination will be upheld if supported by substantial evidence. (Id. at pp. 951-953 [“‘[A] court should tread with extraordinary care’ before reversing an agency’s determination, whether implicit or explicit, that its initial environmental document retains some relevance to the decisionmaking process.”].)
However, once an agency has determined the initial environmental document retains relevancy, the level of deference afforded to its decision not to prepare a subsequent EIR varies based on whether the original document was an EIR or a negative declaration. (Id. at pp. 957-959.) When the agency has previously prepared an EIR, its determination that the changes do not warrant a subsequent or supplemental EIR will be upheld if supported by substantial evidence. (See Committee for Re-Evaluation of T-Line Loop v. San Francisco Municipal Transportation Agency (2016) 6 Cal.App.5th 1237, 1252.) On the other hand, the fair argument standard applies when the initial document was a (mitigated) negative declaration. (San Mateo Gardens I, supra, 1 Cal.5th at pp. 958-959 [“In short, the substantial evidence standard prescribed by CEQA Guidelines section 15162 requires an agency to prepare an EIR whenever there is substantial evidence that the changes to a project for which a negative declaration was previously approved might have a significant environmental impact not previously considered in connection with the project as originally approved, and courts must enforce that standard.”]; see also Friends of the College of San Mateo Gardens v San Mateo County Community College Dist. (2017) 11 Cal.App.5th 596, 606-608 (San Mateo Gardens II).) In so deciding, San Mateo Gardens I ensured that an agency’s determinations regarding the significance of new or more severe potential impacts are afforded the same level of deference as received by the underlying CEQA review document. Accordingly, an agency cannot approve a (mitigated) negative declaration for a project, then make changes to the project, and avoid the fair argument standard of review in determining whether the changes may result in a significant environmental impact. (See San Mateo Gardens I, supra, 1 Cal.5th at p. 959; San Mateo Gardens II, supra, 11 Cal.App.5th at pp. 608-611 [adoption of addendum to mitigated negative declaration was improper where there was a fair argument project changes may result in a significant aesthetic impact].)
Subsequent or Supplemental EIR: Labels Do Not Matter
CEQA Guidelines sections 15162 and 15163 respectively provide guidance on when a subsequent or supplemental EIR is required. The Natural Resources Agency has described subsequent EIRs as complete EIRs that focus on conditions described in section 15162, whereas a supplemental EIR augments the existing EIR. However, in practice, the distinction may be merely academic. In rejecting a challenge alleging a lead agency abused its discretion by preparing a “supplemental” EIR rather than a “subsequent” EIR, the court in City of Irvine v. County of Orange (2015) 238 Cal.App.4th 526 focused on the substance of the document, rather than its title, and found the “supplemental” EIR wholly adequate. (See id. at pp. 538-541.) Both subsequent and supplemental EIRs are subject to public review and notice. (CEQA Guidelines, §§ 15162(d), 15163(c).)
Subsequent Negative Declaration vs. Addendum
CEQA Guidelines section 15162, subdivisions (b) and (c), provide authority for adopting a subsequent negative declaration when changes occur but a subsequent EIR is not required. Likewise, CEQA Guidelines section 15164 permits the lead agency to adopt an addendum under the same circumstances. (CEQA Guidelines, § 15164(a)-(b).)
San Mateo Gardens II states that “a subsequent mitigated negative declaration is at least appropriate where a subsequent EIR would otherwise be required under CEQA Guidelines section 15162 but the project’s new significant environmental effects may be avoided through mitigation measures.” (San Mateo Gardens II, supra, 11 Cal.App.5th at p. 606.) However, nothing in CEQA nor the CEQA Guidelines actually requires an agency to proceed with a subsequent negative declaration rather than an addendum since either is permissible so long as none of the conditions requiring a subsequent EIR occur. (See CEQA Guidelines, §§ 15162(b), 15164(a)-(b).) Proceeding via an addendum is less burdensome on the agency. Unlike a negative declaration, the agency’s significance determinations for an addendum to an EIR need only be supported by substantial evidence. (See Citizens Against Airport Pollution, supra, 227 Cal.App.4th at p. 804; Santa Teresa Citizen Action Group v. City of San Jose (2003) 114 Cal.App.4th 689, 704.) Additionally, a subsequent negative declaration must undergo public notice and review (CEQA Guidelines, § 15162(d)), whereas an addendum “need not be circulated for public review but can be included in or attached to the final EIR or adopted negative declaration.” (CEQA Guidelines, § 15164(c).) Findings are not required when adopting an addendum. (Save Our Heritage Organisation v. City of San Diego (2018) 28 Cal.App.5th 656, 669.) However, it is best practice for the agency to prepare findings to support its determination to proceed via an addendum and to provide a roadmap of the agency’s reasoning for the court.
However, in proceeding by an addendum (or any subsequent review document), the lead agency must correctly identify the underlying project that will be modified to ensure that the addendum is based off of the correct EIR. In Martis Camp, the county sought to abandon a public road between two subdivisions (Martis Camp and the Retreat) and prepared an addendum to the Martis Camp EIR, despite the fact the road was part of the Retreat project and abandonment required no discretionary approval for the Martis Camp project. (Martis Camp, supra, 53 Cal.App.5th at pp. 602-606.) The court ruled the county’s reliance on an addendum to the wrong EIR constituted prejudicial error. (Id. at pp. 606-607.)