Sunridge Power

A reconnaissance-level biological assessment of the power plant site was completed in spring 2026. Because the site sits within an active agricultural field, impacts to rare plants are avoided and impacts to sensitive wildlife habitat are minimized. Targeted seasonal surveys for sensitive species (recommended by the Arizona Game and Fish Department, AZGFD) are planned prior to ground disturbance. The project is consulting with AZGFD and USFWS as necessary to mitigate potential impacts and maintain Endangered Species Act (ESA) compliance. No BLM or other federal land is involved. The biological assessment will be publicly available once finalized.

The site lies within a portion of the Ironwood-Picacho Linkage. AZGFD recommendations to reduce disturbance to wildlife connectivity will be incorporated into the design of both the plant and the transmission line. Design measures recommended by AZGFD address general wildlife (including lighting and fencing) and control of noxious and invasive species. Cumulative impacts from existing and proposed area facilities will be evaluated through agency consultation.

Yes. Environmental field studies are being conducted, including wetland and waterbody delineations, cultural resources, and natural resources surveys, as part of the Arizona Corporation Commission CEC process. The studies will be made available to the public once completed.

Sunridge Power used an estimated number of trips expected during each phase (construction and long-term operational traffic) and assessed the ability of the surrounding roadway network to accommodate those trips. The traffic analysis concluded that the surrounding roadway network is expected to have sufficient capacity to accommodate project-related traffic, even under conservative, worst-case assumptions.

During construction, traffic will be managed through temporary traffic control measures, maintenance of public roadway access, and coordination with Pinal County and other local agencies as needed.

Although specific improvements have not been identified at this phase of the project, Sunridge is committed to working with Pinal County to address roadway improvements that are identified in the future.

The existing roadway infrastructure within the Red Rock area includes pedestrian accommodations, such as sidewalks and crosswalks where applicable, to support safe pedestrian travel. The traffic analysis primarily focused on the vehicular traffic generated by the proposed facility and its effect on the surrounding roadway network. Given the industrial nature of the proposed development and the minimal traffic volumes generated by the development, the project is not expected to result in a meaningful increase in pedestrian-vehicle conflicts. Accordingly, the projected traffic impacts associated with the development are minimal and are not anticipated to adversely affect pedestrian safety, including for school-aged children.

During construction, pedestrian safety will be maintained through traffic control measures, restricted access to active work areas, and maintenance of public roadway access.

Sunridge Power will serve the local electricity market and provide grid reliability for Arizona. Regional power demand is growing at approximately 3.7% annually, which is among the fastest rates in the country. Intermittent renewable resources alone cannot fill this gap; off-peak demand is growing faster than on-peak, creating a grid-flexibility need and not just supply constraints. The project site was chosen due to its proximity to existing power-related critical infrastructure.

The facility uses combined-cycle gas turbine (CCGT) technology, which captures waste heat for meaningfully higher efficiency than a simple-cycle “peaker,” allowing it to provide reliable, cost-efficient baseload power rather than only meeting short peak-demand windows. Anticipated operational life is 30+ years. Incremental efficiency improvements to ancillary and supporting systems may occur over the life of the facility.

The transmission line will consist of steel monopole structures spaced 1,200 to 1,500 feet apart. Line sag and height will be designed per industry standards, local utility standards, and final detail design. Structures will be ASTM A572 carbon steel, hot-dip galvanized, each carrying 3 conductors per phase (745 kcmil, 3 phases). Pole height will be finalized during detailed design but will be between 120 and 195 feet. The number of poles will range from 20 to 30, depending on final design, road crossings, and railroad crossings.

Decommissioning and restoration will follow AZGFD wildlife-friendly guidance to protect the desert landscape and habitat, maintaining wildlife movement, connectivity, and access to resources (for example, preserving natural washes as movement corridors and designing structures, fences, and roadways to allow wildlife passage). See the AZGFD Wildlife-Friendly Guidelines.

Construction and long-term operational noise were evaluated in a technical noise study (CEC Exhibit I - Noise) against existing ambient conditions and Pinal County standards. The study found that noise from the loudest construction activities would remain below existing background levels at the nearest residences and would not be perceptible above ambient conditions. Predicted operational increases are less than 1 decibel (dBA) above ambient conditions, remain well below county industrial noise standards, and are not expected to be perceptible to nearby residents. Construction noise and vibration will be temporary, localized, and managed through daytime construction schedules, phased construction activities, and compliance with County requirements. Based on the study findings, additional noise mitigation measures, such as acoustic walls, are not anticipated to be necessary.

Lighting will be designed to minimize impacts on nocturnal wildlife and to follow dark-sky principles, consistent with AZGFD guidance and applicable dark-sky ordinances. This includes using only the minimum light needed for safety, shielding and aiming fixtures downward to prevent spill, and using motion-sensing and warm or narrow-spectrum lighting (approximately 2700 Kelvin or lower) where possible. See the AZGFD Wildlife-Friendly Guidelines.

The tallest structures are two exhaust stacks, each approximately 199 feet tall.

The nearest Red Rock village homes and schools are approximately 3 miles from the facility, and community facilities approximately 4 miles. Serious incidents are extremely rare; the facility will have a dedicated fire loop, suppression systems, and on-site firewater, along with an Emergency Response Plan covering situations such as gas leaks, fires, and wildfires. Sunridge Power has been coordinating with Rural Metro Fire Department, and that engagement will continue through the design, construction, and operational phases.

Up to two approximately 30,000-gallon tanks will store 19% aqueous ammonia on-site to be used with the selective catalytic reduction (SCR) system and convert NOx emissions into nitrogen (N2) and water. Deliveries will typically occur weekly, based on consumption by the generating equipment, with twice-weekly deliveries possible during periods of high power demand. Chemicals for the boiler condensate system, auxiliary boiler condensate system, and raw water system will be stored in 275 to 330-gallon totes and replaced monthly.

Sunridge Power's primary emissions are NOx and CO, which drive its PSD and Title V air permitting. Advanced emission control technology and systems include SCR, oxidation catalyst (OxCAT), and continuous emissions monitoring (CEMS). Air-dispersion modeling shows the project will not cause or significantly contribute to a violation of any NAAQS nor cause any other adverse impacts to the surrounding area. Startup, shutdown, and upset emissions will be addressed in the facility's permit and tracked via CEMS, with emission controls brought online as quickly as catalyst temperatures allow. Emissions data will be reported quarterly under the Title V permit.

The project received unanimous approval from Pinal County's Planning & Zoning Commission (May 21, 2026) and the Board of Supervisors (June 17, 2026). The site has been zoned industrial since the 1960s and was rezoned to I3, the appropriate current designation. The CEC (Certificate of Environmental Compatibility) application, administered by the Arizona Corporation Commission, is underway, with submission completed in late July 2026 and Line Siting Committee hearings scheduled for September 8-11, 2026.

For Sunridge Power water usage, facility operations will require water for the HRSG process, steam cycle, boiler water, and cooling purposes. In addition, the equipment cooling water system will use a closed-loop cooling water system to cool all plant equipment, greatly reducing the cooling water volume (make-up water) needed when compared to the once-through cooling process. The equipment suppliers will provide noise guarantees in accordance with industry standards, and those values are used to generate initial noise impact estimates. A background noise baseline survey was conducted to form the basis of the noise mitigation actions to be taken by the project to comply with local codes and ordinances. Illumination levels are set based on industry standards, including OSHA Standard 1926.56 and ANSI Standard A11.1. Lighting design is for the safety of the construction and operating personnel.

Sunridge Power provided advance notice for each community meeting. Prior to the April 2026 meeting, property owners within one mile of the project site were notified by letter, and notice was published in the local newspaper. Prior to the June and August 2026 meetings, property owners within one mile of the project site and within one-half mile of the transmission line, as well as the Red Rock Village Homeowners Association, were notified by letter.