TEP power line plan for Sahuarita attacked by mine opponents

Tucson Electric Power's proposed Santa Rita Connection line would bring electricity up to 17 miles to the Sahuarita area from an existing substation on Tucson's far southeast side. The utility has promoted the 138kv line, whose approval is pending before the Arizona Corporation Commission, as a vehicle for providing more power and more reliable electrical service to 14,000 of its customers living south of Tucson, including the Sahuarita area.

The utility says this new line is being planned separately and will be built separately from a second new one that will go to the mine site, in the Santa Rita Mountains southeast of Sahuarita. That line was approved by the Corporation Commission in 2012.

The Santa Rita Connection line is awaiting ACC approval, after having been recommended to the commission this past spring by an advisory panel, the commission's Line Siting Committee. The commission may hold a hearing on the proposed TEP line as soon as next month.

The transmission line is anticipated to cost between $16.5 million and $18 million, depending on which of two possible routes TEP chooses, said utility spokesman Joe Barrios.

But the mine's leading opposition group, Save the Scenic Santa Ritas, argues that the new line will also benefit the mine because the two lines will be linked together through the construction of a new TEP substation that will be built just outside Sahuarita town boundaries. 

And because the mine's potential use of that substation was not publicly disclosed until last month — several months after TEP started informing and meeting with local officials and residents about the proposed power line — the opposition group is charging that "a backdoor deal exists" between TEP and Copper World developer Hudbay Minerals Inc.

That accusation was vehemently denied by TEP officials, Sahuarita Mayor Tom Murphy and several Town Council members at a meeting Monday at which the power line proposal was discussed. Some council members blasted Save the Scenic Santa Ritas' director John Dougherty's accusation as "fake news.

And Hudbay Minerals Inc. called the accusation "completely false" and "irresponsibly misleading."

In a series of recent posts on its website, Save the Scenic Santa Ritas has also expressed concern that TEP's residential and business ratepayers will end up subsidizing the delivery of power to Copper World.

Utility officials deny that also, and say that when a large user such as a copper mine buys power from a local utility to serve its facility, that typically brings down other ratepayers' rates. Hudbay will pay for any infrastructure that serves the mine, TEP has said.

The opposition group has also called on the Corporation Commission to order TEP to prepare an independent analysis of the relationship between the proposed new line and the Copper World line, to ensure the line's construction costs will be properly allocated.

At Monday's Town Council meeting, a TEP spokesman emphatically denied any existence of a "backdoor deal" involving the newly proposed power line.

"The most important message is that there is no secret plan, there is no backroom deal," testified Steven Eddy, TEP's director of public affairs, at that meeting. "The Santa Rita Connection project is a needed public infrastructure project to address real, growing reliability needs in the Sahuarita/Green Valley area."

Customer demand for power in that area is "at or approaching operating limits" for the existing electrical system, he said. "This project is designed to increase redundancy to assure the community can grow."

Much of the debate over this line revolves around the planned Santa Rita Substation, which, unlike the power line, TEP can build without getting Corporation Commission approval. The new TEP line will terminate at the substation, and the power line to the mine will start there. The substation will be built just outside town boundaries.

From the time the ACC approved what's now the Copper World power line (formerly named the Rosemont line) and until recently, Hudbay and its predecessor, Augusta Resource Corp., had planned to run the line to the mine from a new Toro Switchyard it would build in unincorporated Pima County just outside Sahuarita. 

But to save money and to prevent duplication, TEP and Hudbay have agreed to move the operations of the switchyard to the new substation and that Hudbay will make use of the substation. The substation will be built on state land, right next to where the switchyard would have gone — land the utility has leased from the State Land Department.

"So along comes TEP. They lease land immediately next to the Toro Switchyard. What will they bring to the substation?" Dougherty asked Monday in testimony to the Sahuarita council. "There will be a 138 KV connection at the substation. Without it, there's no Santa Rita Connection line and no power to the mine.

"How much of the power from that new line will go to the mine? How much of the cost of that power is going to be shoved off on ratepayers, when in fact the primary draw for that 138 KV connection is the mine? There's no question it is the mine," he said. 

TEP, however, says the power to the mine could just as easily come to the substation from a third line, known as the South Loop line, that will come to the new substation from the Green Valley area to the south. With that line already in place, the mine could get power even if the Santa Rita Connection line wasn't built, said TEP spokesman Barrios.

Building the substation as it's now proposing simply gives TEP and Hudbay an opportunity to "co-locate" the needed infrastructure at one spot, TEP's Eddy said.

A typical 138 kV substation of the size of the planned Santa Rita Substation will cost about $26 million to build, Barrios said.

The mine developer will pay for any substation equipment required to provide service to the mine, said Barrios. How the two companies will split the substation's cost has yet to be determined, TEP says.

Another TEP spokesman, Joe Salkowski, said he can't comment on whether the two companies have started negotiations over how to split the costs. Hudbay's participation in the project would likely lower the costs other TEP ratepayers would have to contribute, the utility has said.

Salkowski said the utility can't say for sure which of the two lines would be supplying power to the mine if the Santa Rita Connection line is built.

"The substation is being built to serve local residents and businesses. Our system is not designed in a way that allows us to add electrons and trace them back to their source. Once you build to an energy grid, the energy flows freely through that system," he said.

"Every part of our grid is connected to every other part of our grid. When we serve a new customer, that customer is served by our entire regional grid, and every resource connected to it. The grid does not work in the way that your question supposes. You'd like accounting of which electrons go where. I’m telling you that’s not how electricity works."

Salkowski and Murphy, the Sahuarita mayor, said they don't see a need for an independent review of the power line proposal to determine if it has any connection to the mine.

"The Santa Rita Connection will be built regardless of whether the mine goes forward. Customers who will be served by it will pay the entire cost of the project, (except) for whatever contributions the mine may make to the substation's costs,"" Salkowski said.

Murphy said, "I never understood why an independent analysis would be necessary. The ACC has a strong staff. That would fall on staff of ACC to do."

In a statement to the Star, Hudbay said, "As TEP publicly stated at the Sahuarita Town Council meeting, the projects it is developing are routine utility business. Characterizing infrastructure development and upgrades as a corporate handout is a deliberate attempt to misinform the community and inflame ratepayers.

"TEP made it clear that Hudbay will pay the full costs of infrastructure built to deliver power to Copper World for its exclusive use."

Save the Scenic Santa Ritas' Dougherty said he's concerned about the lack of early public disclosure of this substation plan. He's been monitoring or attending all the public meetings on the power line project, and reviewing all the public records TEP has submitted about the line to the ACC, and learned nothing about this substation until May 27, he said.

That day, in reviewing the latest batch of documents TEP submitted to the commission on May 26, not long before the commission's Line Siting Committee had a meeting to discuss it, he came across an email exchange from March 2026 between a Sahuarita town official and a TEP official that dealt with the new substation.

"Can you please refresh my memory — is the collocated substation proposed to be built on the parcel owned by Rosemont or the adjacent ASLD parcel?" wrote Anna Casadei, Sahuarita's community development director, on March 12. (The Rosemont Mine was Copper World's predecessor proposal.)  

The Santa Rita Substation will be on a parcel TEP leased from the State Land Department that directly adjoins a parcel owned by Hudbay, replied TEP official Chris Ortiz y Pino.

"The Santa Rita Substation will now house the connection from Copper World. This will be a cost benefit to TEP customers as Copper World will be footing the bill for a portion of this larger substation that will benefit nearly 14k residents in the south of Tucson/Sahuarita," added Ortiz y Pino, TEP's siting, outreach and engagement project manager.

That’s the kind of information TEP "should have said right up front," Dougherty said. "They hid it till the last possible moment. If I hadn’t been following it closely, the public never would have known.

"Our issue is that this (joint use of the substation) was not disclosed and raises the question of how much of the Santa Rita line is going to feed the mine vs. residential customers," he said.

TEP officials said Dougherty mistakenly said in the group's news releases and other public statements that Hudbay and TEP will jointly build and/or operate the new substation. The utility will build and run the substation on its own, the company said.

TEP's Salkowski said details about Hudbay's use of the substation weren't disclosed any earlier because, unlike the utility's power line proposal, the substation was not part of a formal "stakeholder" process in which the utility explains its proposed actions to public officials, various interest groups and other parties.

"Not all of the work that TEP does is associated with public stakeholder processes. Public notification of engineering design decisions is not always provided," he said.