A state line-siting panel is scrutinizing Tucson Electric Power Co.’s proposal to build a new high-voltage power line through midtown Tucson block by block, foot by foot.
Where the new line and its tall poles will run, whether any of it will be built underground to allay affected neighborhoods and what it will cost is still very much up in the air.
A photo of the current view looking south from the east side along North Euclid Avenue, from a point just south of East Speedway (top image), compared with a simulated image of the same point with 138-kilovolt transmission lines and poles installed. The comparison was generated by TEP as part of its bid for approval of its Midtown Reliability Project and is on TEP’s preferred route for the controversial power line.
After an initial day of opening statements, the start of TEP’s testimony, and a public-comment session Monday evening, the state Power Plant and Line Siting Committee began hearing the bulk of TEP’s case Tuesday at the Doubletree by Hilton Reid Park.
That second hearing on TEP’s Midtown Reliability Project came in the wake of a court ruling late Monday that could have a major bearing on the case.
Pima County Superior Court Judge Kyle Bryson upheld the city’s right to restrict overhead installation of utility equipment in certain city-designated corridors, denying TEP’s appeal of a city zoning decision rejecting the utility's plan to erect lines over “gateway” corridors including North Campbell Avenue.
TEP has not said yet whether it plans to appeal the ruling.
The utility’s latest “preferred route” for the 138-kilovolt transmission line avoids running on Campbell and other gateway thoroughfares, though it would cross over them in some spots.
TEP Project Manager Clark Bryner testified that the company’s preferred route in its pending application for a Certificate of Environmental Compatibility avoids running along city-designated gateway routes like North Campbell.
A photo of the current view (top) looking east from a point on the University of Arizona Mall roughly in front of the Meinel Building toward North Campbell Avenue, compared below with a simulated image of the same point with 138-kilovolt transmission lines and poles installed along Campbell. The comparison was generated by TEP as part of its bid for approval of its Midtown Reliability Project but is not on TEP’s preferred route for the controversial power line.
But the preferred route would cross North Oracle Road, also a gateway route, and South Kino Parkway at 36th Street, and also run along a short stretch of East Broadway near Plumer Avenue.
TEP will need to apply to the city for “special exceptions” to the ordinances for those crossings, under a process approved for transmission projects last year, Bryner said.
Bryner said that in addition to the city-designated gateway and scenic corridors, many of the route segments, especially on the north end of the project, would traverse historic neighborhoods that are subject to historic district rules, neighborhood plans and area plans.
TEP has said it is not opposed to installing the new transmission line underground but has said it won't propose raising electric rates to pay for the cost of undergrounding at 10 to 20 times the cost of overhead lines or some $60 million at the low end for the entire roughly 7-mile route.
But Tucson voters in May 2023 rejected a new city franchise agreement with TEP that included a new fee on the electric bills of city residents to help pay for underground transmission line installation.
'No place' in neighborhoods
A photo of the current view looking north along South Euclid Avenue, from a point just north of East 36th Street (top image), compared with a simulated image of the same point with 138-kilovolt transmission lines and poles installed. The comparison was generated by TEP as part of its bid for approval of its Midtown Reliability Project and is on TEP’s preferred route for the controversial power line.
TEP’s current preferred route for the transmission line would traverse or border several neighborhoods with various historic designations, including Jefferson Park, North University, West University, Pie Allen and Iron Horse.
TEP detailed its efforts to reach out to the public about the project, which since the start of the latest line-siting application has included four public open houses, 13 neighborhood "listening sessions," four neighborhood advisory group meetings and meetings with public agencies and officials.
The company said it has received more than 500 comments from the public.
During Monday’s public comment, a parade of residents told the committee the proposed transmission line with poles 75 to 100 feet tall have no place in their neighborhoods.
TEP’s current preferred route would avoid an initial proposal to run the line up North Campbell, bordering the historic Sam Hughes neighborhood.
TEP attorney Megan Hill said the company picked a preferred route away from Campbell not primarily because of the potential cost but because of the potential further delays to the project.
But Sam Hughes leaders said overhead lines don’t belong in any residential neighborhood, and undergrounding the transmission lines is the only solution aesthetically and legally and have been economically feasible in other communities.
“The huge poles being proposed have no place in or near any historic neighborhood,” Sam Hughes Association President Gayle Hartmann said. “We are not suggesting that the project as proposed should be sited somewhere else. A recommendation that was put forth some months ago proposed that above-ground poles would be acceptable in industrial areas, but in all other locations, the poles need to be underground.”
“TEP is apparently in deep denial of aesthetic values that are important to any city and Tucson residents agree that in general, industrial scale power poles are not appropriate in midtown Tucson,” said Vytas Sakalas, a member of the Sam Hughes board.
Some residents said they worry that a new high-voltage transmission through their neighborhoods could drop their property values, citing figures from 5% up to 40%, and cause them to lose their historic designations — along with important tax breaks.
Blenman-Elm historic neighborhood resident Randy Hotchkiss said he has seen estimates of up to 40% loss of property values for homes very close to high-voltage power lines.
“Tucson is a wonderful place to live, and we want to keep it that way,” Hotchkiss said. “TEP’s 138-kV above-ground power line structure will severely visually impact the gateway to Tucson and the University of Arizona. We rely on this gateway to attract visitors, and to attract businesses.”
“If you put giant power poles in front of historic buildings, not only could the individual buildings lose their national registered listing, the entire streetscape loses its listing and potentially the entire neighborhood,” said Diana Lett, treasurer of the Feldman’s Neighborhood west of Banner – University Medical Center, citing an approximate 50% increase in property taxes if historic exemptions are lost. “This is a very big deal for people trying to age in place.”
In Arizona, homes on the National Register of Historic Places are eligible for county property-tax credits of up to 45%.
But Bryner said TEP does not believe overhead lines affect historic designations because the utility ultimately would be removing a significant amount of old 46kV lines and distribution equipment as part of the upgrade.
Tracing the line
TEP’s preferred route for the transmission line, identified as “B4” in project materials, connects the DeMoss-Petrie Substation near Interstate 10 and East Grant Road to the proposed Vine Substation near Banner – UMC via Grant, North Park Avenue, East Adams Street and North Vine Avenue.
The route connects the Vine Substation to the Kino Substation at South Kino Parkway and East 36th Street using Vine, Adams and Park before turning west on East Speedway and then south on South Euclid Avenue. After crossing Barraza Aviation Highway, the route continues on South Toole Avenue, Euclid and 36th Street.
Christine Villela said she and her father own eight rental homes along East Adams Street that would see high-voltage power lines overhead as part of TEP’s preferred route.
Villela said the lines are inappropriate for a residential area and the radiation from the lines poses a health risk to residents.
“There is no reason that if the plan is approved the lines through Adams Street should not be underground — the length is less than 2,000 feet,” she said. “There is nothing that would make it expensive or difficult to place these lines underground. I’m not aware of any government entity that has allowed high- powered, above-ground lines to go directly over pre-existing residential houses where young people are living.”
Bryner said the various potential route segments were evaluated and scored based on an array of factors, including adjacent land use, such as residential, commercial or industrial; available setback of structures for a line easement; existing utility infrastructure; special city and historic district designations; the impact on low-income residents; and expected costs for each route.
Larger arterial roads that already have poles and other utility infrastructure generally were preferred for their existing rights-of-way and views, he said.
Parts of one proposed route along North Campbell Avenue already have lower-voltage power poles, but there are no 138kV lines installed anywhere in the line-siting study area, Bryner said.
Painting a picture
A photo of the current view looking west along East Adams Street, from a point just west of North Vine Avenue (top image), compared with a simulated image of the same point with 138-kilovolt transmission lines and poles installed. The comparison was generated by Tucson Electric Power Co. as part of its bid for approval of its Midtown Reliability Project and is part of TEP’s preferred route for the controversial power line.
So what will Tucson residents see if and when new, overhead lines and poles are installed?
TEP officials discussed the size, installation and finish of the metal poles that will hold up the new 138kV transmission line. The company has generated dozens of simulated images before and after line installations to help visualize potential views at key points along various proposed routes, as well as a flyover video.
Bryner said though public materials cited a pole height of 75 to 130 feet, and opponents often cite the higher figure, most of the poles will be 75 feet.
Taller poles will be used to cross major streets and other features like bridges, or where the wires, known as conductors, are placed on both sides of a pole, he said.
The poles are tapered, with a base diameter of about 30 inches on the 75-foot poles, while the tallest poles have bases about 60 inches in diameter, Bryner said.
TEP has shown and offered three pole exterior finishes: weathered, in which the steel is allowed to accumulate surface rust; galvanized, which is treated with rust-resistant zinc coating; or painted in a light-green “Mohave sage” color.
Using steel and allowing it to weather is the cheapest option, Bryner said.
Galvanized steel is more expensive, while painted poles are the most costly because they typically must be repainted every decade or so at a cost of about $1,000 a year, TEP said.
Environmental concern
During the public comment session Monday, midtown resident Matt Somers cited the environmental danger of a gas TEP plans to use to insulate equipment at its proposed new Vine Substation.
Somers cited estimates by the U.S. Environmental Protection Agency that the gas, sulfur hexafluoride, is one of the most potent greenhouse gases, trapping 23,500 times the heat as carbon dioxide traps.
The European Union has begun phasing out SF6, and it is targeted for monitoring under international climate accords.
Under questioning, TEP senior vice president Erik Bakken said TEP uses SF6 as an insulator at many of its substations under close monitoring, acknowledging the climate concerns while noting that SF6 is non-toxic to humans.
Last year, Bakken said, TEP tracked the loss of 32 pounds of SF6 from all of its facilities.
Proposed routes bus tour
On Thursday, the siting committee members and intervenors took a daylong bus tour of various proposed transmission-line routes.
Because the tour was part of the official proceeding, committee members were not permitted to chat about the project while on the tour under state rules restricting such informal communications among members.
TEP generated and filed a tour narrative as part of the committee record, and a court reporter went along to record committee members' questions and comments at tour stops.
On Friday, TEP officials started technical testimony about the cost and time of undergrounding transmission lines versus overhead installation.
TEP’s consulting engineer Jason Jocham, vice president of the Phoenix-based firm Sargent & Lundy, testified how high-voltage transmission lines are much more costly and time-consuming to install than overhead transmission lines.
Cost of undergrounding
TEP says it has no underground transmission lines on its system though it regularly installs lower-voltage, neighborhood-level distribution lines at customer request, at the customers’ cost, Larry Robinson, TEP director of land, engineering and project management told the siting panel.
Underground transmission lines use special, insulated wire conductors that are placed in a conduit pipe in a trench at least a few feet deep up to about 10 deep, and encased in concrete, with vaults for maintenance installed about every 1,600 feet, Jocham said.
Heavily insulated, underground transmission lines cost some four times the cost of bare overhead wire, Bryner said.
Capacity can also be an issue, since underground lines lower safe operating temperature can limit the amount of power they can handle compared with overhead lines, Jocham said.
Underground lines are monitored for operating temperature by a sensor system, and utilities will often add a spare wire conductor to use in case a main conductor malfunctions, also adding to costs, he said.
Jocham said if the line were required to be placed underground it likely would not be in service by a planned 2027 service date.
Contractors typically take about a day to install 100 feet of line, or about four months per mile, compared with one to two months per mile for overhead installations, he added.
Hearings continue
Hearings before the state Power Plant and Transmission Line Siting Committee are scheduled to continue daily next week, with the City of Tucson and Underground Arizona, a nonprofit group opposed to overhead lines, presenting their cases after TEP concludes.
Banner-University Medical Center-Tucson, which has negotiated the placement of the proposed new Vine Substation at its northwest corner, also has intervened as a party in the line-siting case.
Michelle De Blasi, an attorney for Banner-UMC, said the hospital supports the utility’s preferred route, amid assurances the line will not interfere with or pose a hazard to air-ambulance helicopter operations.
Banner is one of only two Level 1 trauma centers in Southern Arizona, along with Carondelet St. Joseph’s Hospital on Tucson’s east side.
For links to the live hearings and other information, go to tucne.ws/tepline.
