Geothermal Injection Capacity Expansion

2026010762

California Energy Commission

NOE - Notice of Exemption

1/23/2026

1/23/2026

Erica Loza

California Energy Commission

Electric Generation System Specialist I

Lead/Public Agency

1716 P Street
Sacramento, CA 95814

(279) 226-1095

erica.loza@energy.ca.gov

41°29'30"N 120°32'24"W

96101

900 North Main Street

Categorical Exemption

Cal. Code Regs., tit 14 § 15301, Cal. Code Regs., tit 14 §15302

Cal. Code Regs., tit. 14 § 15301 provides that the operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing structures, facilities, mechanical equipment, or topographical features involving negligible or no expansion of existing or former use are categorically exempt from the provisions of CEQA. This project will involve minor alteration of existing structures involving negligible or no expansion of existing or former use. This project will increase injection capacity for a geothermal heating system currently serving the Modoc Medical Center, Modoc Schools, and swimming pool by converting an existing, unused geothermal production well into an injection well. Existing pipelines will be accessed, and new pipelines will be installed in the parking lot and roadways of the High School. This conversion only entails modest alterations to the unused production well and geothermal heating system and makes no significant changes to roads, the well pad, or surrounding vegetation, nor does it entail complicated modifications, such as major reconstruction of the injection well. The well is currently unused but was formerly a geothermal production well connected to a geothermal aquifer. The production well will be converted to an injection well to inject geothermal water after heat extraction into the same geothermal aquifer. The injection well will be cleaned and opened to its original drilled depth. The integrity of the injection well casing will be tested to ensure injected geothermal water is not allowed to escape, meaning it will be geologically confined within the injection well until it reaches the appropriate depth to remain in the aquifer. Although unlikely, there is a possibility that the injection well may be deepened slightly to increase injection capacity. All trenching will be conducted in previously disturbed areas, such as the parking lot and roadways of the High School. Project activities will be performed in accordance with all applicable rules and regulations, including obtaining a permit for the well modifications from the California Geologic Energy Management Division. Cal. Code Regs., tit. 14 § 15302 provides that the replacement or reconstruction of existing structures where the new structure will be located on the same site as the structure replaced and will have substantially the same purpose and capacity as the structure replaced are categorically exempt from the provisions of CEQA. This project will involve the replacement or reconstruction of existing structures, where the new structure will be located on the same site as the replaced structure and will have substantially the same purpose and capacity as the structure replaced. This project is comparable to the replacement or reconstruction of existing utility systems involving negligible expansion of capacity, as described in Cal. Code Regs., tit. 14, § 15302 (c). This project will convert an existing unused geothermal production well into an injection well. The former production well, converted to a new injection well, will serve the same purpose- to provide geothermal heating to Modoc Medical Center facilities. Although the well is currently unused, it was formerly a geothermal production well with production capacity for heating. This project will convert the production well to an injection well in order to increase capacity for Modoc Medical Center’s geothermal heating system. The project will not impact an environmental resource of hazardous or critical concern where designated, precisely mapped, and officially adopted pursuant to law by federal, state, or local agencies; does not involve any cumulative impacts of successive projects of the same type in the same place that might be considered significant; does not involve unusual circumstances that might have a significant effect on the environment; will not result in damage to scenic resources within a highway officially designated as a state scenic highway; the project site is not included on any list compiled pursuant to Government Code section 65962.5; and the project will not cause a substantial adverse change in the significance of a historical resource. None of the exceptions to categorical exemptions listed in CEQA Guidelines section 15300.2 apply to this project, and this project will not have a significant effect on the environment. Therefore, the project will not have a significant effect on the environment and is categorically exempt under CEQA Guidelines sections 15301 and 15302.