Use, Not Risk: California Supreme Court Clarifies CEQA’s Class 1 Exemption
Sunflower Alliance v. Department of Conservation et al., Reabold California, LLC, Real Party in Interest and Appellant, was decided by the California Supreme Court on June 25, 2026. The Court held that “negligible or no expansion of existing or former use” in the California Environmental Quality Act’s Class 1 categorical exemption refers to the nature or degree of a change in use, not to the environmental risk created by that change. It reversed the First District Court of Appeal and remanded for reconsideration under the correct standard.
Background
The Proposed Conversion and Agency Approval
Reabold proposed to reopen the Ginochio Well in the Brentwood Oil Field. The well was constructed in 1963, used for oil and gas extraction until 1984, and later plugged. Reabold sought approval from the California Department of Conservation’s Geologic Energy Management Division, or CalGEM, to convert it into a water injection well for treated wastewater from nearby oil operations.
Reabold’s active wells produced approximately 300 barrels, or 12,600 gallons, of wastewater each day. The company proposed injecting approximately 10.95 million barrels into an exempt aquifer over 20 years rather than trucking the wastewater offsite.
CalGEM and water regulators initially raised concerns about fluid migration into usable groundwater. The record identified a nearby fault, abandoned wells that could act as conduits, and active water wells drawing from overlying aquifers. After further technical submissions, CalGEM imposed conditions requiring pressure testing, reporting, and recalculation of the zone of endangering influence if actual conditions exceeded estimates.
CalGEM then issued a project approval letter and notice of exemption. It concluded that the project qualified under CEQA Guidelines section 15301 because it involved a minor alteration of an existing well and a negligible expansion of former use. It also found that the unusual circumstances and cumulative impacts exceptions did not apply.
Trial Court and Appellate Court
Sunflower Alliance petitioned for a writ of mandate, arguing that converting a plugged extraction well into an active wastewater injection well was not a negligible expansion of use. The Contra Costa County Superior Court agreed, concluding that injecting wastewater was materially different from extracting oil and gas, and directed CalGEM to set aside the notice of exemption.
The Court of Appeal reversed. It treated the relevant inquiry as whether the changed use created more than a negligible risk of environmental harm. Because regulators had concluded that the wastewater would remain confined and the risks were negligible, the court held that the project fit within Class 1.
The Supreme Court’s Decision
The Supreme Court rejected that risk-based interpretation. Section 15301 requires an agency to compare the nature and scope of the proposed use with the facility’s existing or former use.
The Court also rejected Sunflower Alliance’s argument that any new use necessarily falls outside Class 1. A new use may qualify, but only when the change in the nature or degree of use is itself negligible. The examples in section 15301, including adding bicycle lanes to an existing street and converting a residence to office use, show that some changes in use remain within the exemption.
Reasoning and CEQA’s Review Structure
The Court emphasized that categorical exemptions reflect determinations by the Secretary of the California Natural Resources Agency that specified classes of projects typically do not have significant environmental effects. A lead agency or reviewing court may not replace the text of an exemption with its own assessment that a particular project appears environmentally benign.
A contrary rule would collapse CEQA’s separate analytical stages. The exemption inquiry precedes the detailed review that may result in a negative declaration, mitigated negative declaration, or environmental impact report. Treating low environmental risk as the Class 1 test would require an abbreviated environmental review at the exemption stage without the public participation and disclosure safeguards associated with formal CEQA review.
Environmental effects remain relevant when an exception is asserted, particularly the unusual circumstances exception. That inquiry is distinct and requires both unusual circumstances and a fair argument that those circumstances may cause a significant environmental effect.
Issues Left Open
The Supreme Court did not decide whether substantial evidence supports CalGEM’s determination that this well conversion is a negligible change in use. That issue returns to the Court of Appeal. The Court also declined to decide whether CalGEM’s conditions were permissible regulatory requirements or impermissible mitigation measures used to secure an exemption.
Justice Kruger concurred, emphasizing that “negligible” is a relative term requiring a frame of reference. She suggested that agencies and courts may use the examples in section 15301 as benchmarks. Her concurrence recognized a limited role for environmental considerations while agreeing that environmental risk cannot be the sole test.
Conclusions and Implications
The decision clarifies that the threshold Class 1 inquiry is functional. Agencies must identify the former or existing use, define the proposed use, and determine whether the change in nature, intensity, duration, or operational scope is negligible. Evidence that a project is well regulated or unlikely to cause harm does not independently establish eligibility for the exemption.
Project proponents should build an administrative record that directly compares former and proposed uses rather than relying primarily on technical evidence of environmental safety. Because the Court remanded without deciding the exemption’s ultimate applicability, further proceedings may provide additional guidance on when a new use is sufficiently analogous to a former use to qualify as negligible under section 15301.
This article was originally published in the September 2026 edition of the California Land Use Law & Policy Reporter. It is posted here on our website with the permission of California Land Use Law & Policy Reporter, Argent Communications Group, Argent & Schuster, Inc., and the author, Darien Key. All rights remain with the original publisher.
Darien Key is a Land Use and Natural Resources Attorney based in Oakland. Darien’s practice focuses on Land Use entitlement (such as the Subdivision Map Act, Housing Accountability Act, and Builder’s Remedy), CEQA (California Environmental Quality Act), municipal law (such as the Brown Act, Public Records Act, Conflicts of Interest, etc.), water (SGMA compliance and groundwater adjudications), and related environmental laws both on the transactional side but also in litigation. He can be reached at dkey@fennemorelaw.com.