Rio Rico-Harshaw 138kV Transmission Line Project

UniSource Energy Services is developing plans for the new Rio Rico to Harshaw 138 Kilovolt (kV) Transmission Line Project.

The Rio Rico to Harshaw Line will involve the construction of an approximately 20-30 mile, single-circuit 138 kV transmission line mounted on steel monopole structures. The project will interconnect UniSource’s existing 138 kV transmission system to the Proposed Harshaw Substation through a Proposed 138 kV switchyard in Rio Rico.

The Rio Rico to Harshaw Line will serve the Hermosa Project, a mine exploration project located in Santa Cruz County that is owned by Arizona Minerals Inc. (AMI), a subsidiary of South32. The Hermosa Project is currently in the pre-feasibility phase. The line also will improve service reliability for all electric customers in the San Rafael Valley, Washington Camp and Lochiel areas of Southern Arizona. The Hermosa Project currently is served by UniSource through an existing 13.2 kV distribution line that is not adequate to support the Hermosa Project’s anticipated energy needs.

Project Details

UniSource invites members of the public to ask questions, submit comments and learn more about the project at a hybrid in person and virtual open house meeting:

Thursday, November 17, 2022 | 6-8 p.m.

Quality Hotel Americana Nogales – Mayan Room
639 N. Grand Ave.
Nogales, AZ

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