A GUIDE BY TABS

· In-Person Public Open House:
Wednesday, September 3rd, 10 am to 12 pm (presentation begins at 10:30 am)
Tubac Golf Resort, Geronimo Room

· 

Virtual Public Open House:

Thursday, September 4, 2025, 4 to 5 pm
Link will be posted to the Unisource Project Webpage

For more information and their current interactive map click here.

They have posted a revised proposed map identifying various routes the new electric lines may run.

Thanks to your input and letters, part of the western proposed route has been removed as an option, but there are still concerns. Your attendance and questions will be important as this siting process continues with Unisource.

> The best case scenario for both UNS Electric and Santa Cruz County (SCC) customers/ratepayers is to meet future electric reliability and increased power needs by utilizing the existing 138kV power line easement east of the Santa Cruz river.

> There are several existing north/south running easements owned by various entities, but only the UNS eastern power line route meets the requirements of an existing monopole structure located on 100’ wide easement route, traversing mostly undeveloped land which is primarily barren scrub mesquite not posing a significant wild land fire danger.  The one area where the line passes through homesites is a relatively short area east of Pendleton Road as the line crosses over that road toward the Canez substation.  The aforementioned houses were built after the 138kV line was constructed in the 2005 timeframe.

> The Union Pacific rail line as well as I-19 are easements that would be difficult for UNS to procure in my opinion.

> The “El Paso” natural gas pipeline, although currently owned by UNS is only 40’ in width, in close proximity to residential homes, traverses conservation easements/ranches and poses potential dangers of interaction between these two sources of energy if some type of accident should occur.  This gas line easement in some recorded deeds expressly prohibits any overhead power lines.  In addition, any required width increase of this current easement would require eminent domain involvement costing unknown amounts of money, not to mention the amount of time in litigation with no guarantee of success.

> The use of United States Forest Service (USFS) land, through any route on the far western side of I-19, would receive significant public outcry due to environmental impact, involve very significant engineering/construction costs, and be at a much higher level of wildfire danger, especially with only remote, inadequate road access for equipment.  These were some of the reasons the USFS declined to support this potential route in an earlier line siting case.

> The existing 138kV power line route that runs from the Kantor substation in Amado to the Canez substation in Rio Rico, then to the Sonoita substation in Rio Rico and finally to the Valencia substation in Nogales was designed to be double circuited which would provide all the necessary power needed for future growth in Santa Cruz County as well as the maximum power eventually required to operate the South 32 mine in the Patagonia mountains.  There is no need for a 138kV power line to cross over I-19 to a western route and then cross again to supply power for the mine at the proposed new line route from the Sonoita substation.  The proposed Gateway substation doesn’t need a separate 138kV power line to provide power to western Nogales, a lessor amount of power would suffice.  Does UNS have a hidden agenda to sell power to Mexico and therefore wants a dedicated western route?

> The Arizona Corporation Commission (ACC) mandated that UNS  improve the electrical power reliability for SCC after previous power outages and that was primarily accomplished with the replacement of the 115kV H-frame wooden poles with the current 138 kV metal monopoles, plus improvements to substation equipment.  There was no requirement to have a looped transmission line.   A looped line may improve reliability in some cases versus a double circuited line, but transmission lines are protected from lightening strikes and it is the substations that have experienced issues more so than the actual power poles/lines.  Would a parallel 138kV line on the existing 100’ eastern easement qualify as a loop?  It may, but is the extra expense warranted versus double circuiting the existing monopoles?  I believe the slight increase in a line outage does not justify the expense of a separate line, whether that line is closely adjacent or separated by a few miles.

> The 46kV backup power line from the Canoa substation to the Kantor substation is in place to supply power to the northwest areas in SCC while the backup generators (73 MW) at the Valencia substation plus the one at the Wastewater Treatment Plant in Rio Rico (10 MW) can provide for Nogales and Rio Rico, given that they are maintained and function properly.  SCC currently uses about 60 to 85 MW’s of power on a given summer day and as stated at the May 2025  open house presentation in Tubac, the current 138 kV power line is sufficient to provide power to SCC as well as the South 32 mine!.

> In my opinion, double circuiting the existing 138kV power line, per its design, is the best solution for SCC and certainly makes sense both cost and time wise for UNS; not to mention the lessor cost burden to customers and the fact that there will be no detrimental effects to the environment or view sheds and no public outcry.
>
> Respectfully submitted,
> Rich Bohman