Southline Transmission, L.L.C. is requesting that the Arizona Corporation Commission (ACC) amend its existing Certificate of Environmental Compatibility (CEC 173), originally issued in 2017 and amended in 2021. The proposed amendment would extend CEC 173 to include the remaining 57 miles of the WAPA upgrade segment. If approved, the entire Southline Project within Arizona would be covered under a CEC.This upgrade segment was fully reviewed and permitted through the NEPA process between 2012 and 2015. The CEC amendment represents one of the final permitting submissions for the Southline Project.
Southline Transmission, L.L.C. invites the public to its public hearing before the Arizona Power Plant and Transmission Line Siting Committee (Committee). Southline Transmission, L.L.C. is submitting an Application to amend the Certificate of Environmental Compatibility (CEC) granted by the Committee in Line Siting Case No. 173 (CEC 173) to obtain a CEC for the Apache to Vail Upgrade Section of the Southline Transmission Project.
The hearing on the CEC Application will be held at the DoubleTree by Hilton Tucson – Reid Park, 445 South Alvernon Way, Tucson, AZ, 85711. The hearing will begin Monday, January 12, 2026, beginning at 1:00 P.M. and will continue as necessary through Friday, January 16, 2026, commencing at 9:00 A.M. each day at the same location through the completion of the hearing.
The committee will hear public comments in a special event session on January 12, 2026, beginning at 5:30 P.M. Comments may be presented in-person at the DoubleTree by Hilton Tucson – Reid Park, via telephone, or via Zoom. The public also has the option to watch the hearing online or listen to the hearing via telephone. All hearing access links are provided below. Please note that virtual links will remain inactive until the scheduled hearing dates.
| Project | Event | Dates | Link | Notes |
|---|---|---|---|---|
| Southline CEC Hearing | Hearing Vimeo link for live feed | 1/12/26 - 1/16/26 | https://vimeo.com/event/5496169 | For the public to view CEC hearings |
| Public comment Zoom link | 1/12/26 | Join Zoom Meeting: https://us06web.zoom.us/j/87666050240 Meeting ID: 876 6605 0240Passcode: N/A Call In Number: +1 (719) 359-4580 | For the public to participate in the comment session starting at 5:30pm on 1/12/26 | |
| Public comment Vimeo link | 1/12/26 | https://vimeo.com/event/5496174 | For the public to view the Public Comment Period |
| Project | Event | Dates | Link | Notes |
|---|---|---|---|---|
| Southline CEC Hearing | Hearing Vimeo link for live feed | 1/12/26 - 1/16/26 | https://vimeo.com/event/5496169 | For the public to view CEC hearings |
| Southline CEC Hearing | Public comment Zoom link | 1/12/26 |
Join Zoom Meeting:
https://us06web.zoom.us/j/87666 Meeting ID: 876 6605 0240 Passcode: N/A Call In Number: +1 (719) 359-4580 | For the public to participate in the comment session starting at 5:30pm on 1/12/26 |
| Southline CEC Hearing | Public comment Vimeo link | 1/12/26 | https://vimeo.com/event/5496174 | For the public to view the Public Comment Period |
Physical copies of the CEC Application are also available for review at the following locations:
Pre-Filing Conference Materials
Pre-Hearing Conference Materials
Potential Route Tour Itinerary and Maps
CEC Line Siting Committee Hearing Transcripts
Downloads
CEC Amendment Area Flyover
Questions and comments can be submitted to:
connect@southlinetransmission.com
(520) 485-5764
Southline CEC
343 W. Franklin Street
Tucson, AZ 85701
Building America's Next-Generation Infrastructure to Power Our Future.
Black Forest Partners and Grid United are co-developing Southline Transmission Project.
© 2026. Grid United LLC. All Rights Reserved.
Southline Transmission, LLC. invites the public to participate at a public hearing before the Arizona Power Plant and Transmission Line Siting Committee (Committee). Southline Transmission, LLC. is submitting an Application to amend the Certificate of Environmental Compatibility (CEC) granted by the Commitee in Line Siting Case No.173 (CEC 173) to obtain a CEC for the Apache to Vail Upgrade Route of the Southline Transmission Project.
January 12, 2026 | 1:00 PM – 5:30 PM
January 13 – 16, 2026, as needed | 9:00 AM – 5:00 PM
DoubleTree by Hilton Tuscon -Reid Park
445 South Alvernon Way, Tucson, AZ, 85711