California Supreme Court Interprets CEQA’s Existing Facilities Exemption in Oil Well Conversion Case

The California Supreme Court has provided important guidance on the use of categorical exemptions in the CEQA process. Sunflower Alliance v. Department of Conservation, 2026 WL 1830258 (Cal. Supr. Ct., June 25, 2026). Interpreting CEQA’s widely used Class 1 Existing Facilities exemption, the Court held that the exemption’s limitation to projects involving “negligible or no expansion of an existing or former use” can include new uses at an existing facility. But, reversing the Court of Appeal’s interpretation, the Court then held that whether an expansion of use is “negligible” depends on the nature and scope of the proposed expansion and not on whether the expansion involves “negligible” risk of environmental harm.

The Court of Appeal’s Approach

We previously covered the underlying dispute in our December 6, 2024 update, “California Court Upholds CalGEM’s Use of CEQA Categorical Exemption for Approval of Oil Well Conversion Project.”

Reabold California LLC, an oil and gas exploration and production company, applied to the California Department of Conservation’s Geologic and Energy Management Division (CalGEM) for permits to convert a plugged and abandoned oil well into a wastewater disposal well. Reabold proposed to remove the well plug, install wastewater injection equipment within the existing wellbore, and utilize an existing well-pad and access road to service the injection well. In compliance with CalGEM regulations for “Class II” underground injection control (UIC) wells, CalGEM reviewed and considered technical reports submitted by Reabold addressing project engineering and geologic and hydrogeologic conditions, which concluded that injected water would be geologically confined to the intended receiving zone. 

CalGEM approved the conversion to a UIC disposal well and issued a CEQA Notice of Exemption citing the “Class 1” or “Existing Facilities” Exemption, which applies to the permitting and “minor alteration” of existing facilities “involving negligible or no expansion of existing or former use.” The Sunflower Alliance, an environmental nonprofit, sued to set aside CalGEM’s authorization of the well conversion.

As a matter of law, the Court of Appeal held that a “negligible” expansion of use within the meaning of CEQA’s Existing Facilities exemption “is intended to allow changes or expansions in use that are inconsequential,” meaning the exemption applies “if the risk of environmental harm from the new use is negligible.” The Court of Appeal rejected Sunflower’s argument that any change in use of a modified well is ineligible for the Class 1 exemption. Instead, the Court found that “focusing on the environmental consequences of a change in use is a better approach.” Applying its newly announced negligibility test, the Court of Appeal upheld CalGEM’s use of the Existing Facilities exemption after determining that the proposed change in use involved negligible environmental risks because injected water would not escape the target injection zone.

Supreme Court Reversal and Plain-Language Reading of the Existing Facilities Exemption

The Supreme Court reversed, concluding that both the plaintiff’s and the Court of Appeal’s interpretations of the exemption were inconsistent with its plain language.

In rejecting the plaintiff’s argument, the Court noted that the text of the Class 1 exemption provided examples of eligible projects, and these included projects involving changes of use, such as conversion of a single-family residence to office use and use of a single-family residence as a small family day care home.

In rejecting the Court of Appeal’s conclusion that the relevant inquiry under the exemption was whether a change in use would result in a negligible risk of environmental harm, the Court found the argument conflicted with the language of the exemption, which links the word “negligible” to “use” and does not mention risk of environmental harm. 

Finally, the Court acknowledged that in various contexts a lead agency’s determination of whether a categorical exemption applies to a project will itself necessitate some level of environmental impact analysis. For example, some classes of categorical exemptions apply only if the lead agency rules out certain environmental impacts, and all categorical exemptions must be rejected if “unusual circumstances” show that an otherwise-eligible project would have a significant environmental impact. The Court was unwilling, however, to endorse a judicially-created rule that would shift still more environmental impact analysis into a lead agency’s exemption determination, thus foregoing the “full benefit of the public review and other procedural safeguards” that a negative declaration or an environmental impact report would provide. 

The Court remanded the case to the Court of Appeal for further proceedings using the Court’s interpretation of the Class 1 exemption. The Court also left open the possibility that the Court of Appeal could consider CalGEM’s reliance on a second exemption that was not before the Court: CalGEM’s own industry-specific “class 1 equivalent” exemption, which specifically includes conversion work on both oil and injection wells.