PUC Docket No. 36978
Electric Transmission Texas LLC (“ETT”) filed its application on July 10, 2009, requesting approval to construct a proposed 138 kV transmission line in Uvalde and Medina Counties, Texas.
The project will be located between Uvalde and Castroville and will require approximately 70 miles of new circuits. It is estimated to be energized in April 2012. The proposed transmission line will connect the existing AEP Uvalde Substation and the existing CPS Castroville Substation. ETT will construct, own, operate and maintain the portion of the project from the Uvalde Substation to the interconnection point with CPS’s service area boundary. CPS will construct, own, operate and maintain the portion of the project beginning at this point and continuing to the Castroville Substation. ETT proposes to use single pole structures for this project because they provide the lowest installation costs for the application and have a more compact design than lattice towers or the two-pole H-frame design.
The Preferred Route would include the use of existing right-of-way for approximately 13 miles, where an existing 69 kV line would be rebuilt as a double-circuit line with a 69 kV circuit on one side and the new 138 kV circuit on the other. The width of required right-of-way ranges from 80-100 feet. In addition to the cities of Uvalde and Castroville, the incorporated cities of Sabinal and Hondo, and the unincorporated communities of Knippa, D’Hanis, Quihi, Dunlay, and Rio Medina are located in the area. The estimated total cost of the project is $82,523,000.
ETT states that the purpose of the proposed line is to improve system reliability in the area by relieving overloading and under-voltage conditions on the existing transmission facilities in the general area. In addition, the project will increase the transfer capability from generation sources in the San Antonio and Central Texas area into the AEP Western Region. ETT also claims that the proposed line will relieve thermal overloading. ERCOT Board of Directors recommended a AEP Uvalde to CPS 138 kV transmission line, saying that the project is “needed to support the safety and reliability of the ERCOT Region transmission system.”
ETT states that it considered one other alternative, a rebuild of the 111-mile Sonora to Uvalde 69 kV transmission line and converting it to a 138 kV line to supply power to the Del Rio area from the north. This alternative was estimated to cost more than $65.5 million more than the proposed project. Because of reliability issues and the multiple electric utilities involved, distribution alternatives were not considered a viable option. Distributed generation was not an option because neither ETT nor AEP TCC is a bundled utility.
An engineering firm, PBS&J, was contracted to provide a routing study and environmental assessment. PBS&J’s report describes in detail the process of its evaluation of alternative routes. Three public meetings were hosted in May 2008 to solicit public input on the proposed route. In response to public input and landowner concerns, several links were modified to reduce impacts to habitable structures and other constraints. In addition, some new links were added and others deleted. An additional public meeting was held to present the new links and to gather public input. PBS&J identified 18 alternative routes that were then studied in more detail and evaluated by its staff, using 38 environmental and land-use criteria. The PBS&J staff reached a consensus and recommended a recommended preferred route.
ETT and CPS Energy each independently evaluated the recommendation of PBS&J to determine a preferred route. The application states that, after these evaluations, each independently selected Route 17 as the preferred route.
CPS is a municipally-owned utility and is not subject to the jurisdiction of the PUC with regard to the certification of transmission facilities. After the CPS Energy Board approved construction of its portion of the preferred route, ETT requested that PBS&J analyze four additional routing combinations that were not previously evaluated. The application describes several actions that reduced the final number of routes under consideration to nine. PBS&J then re-evaluated the nine routes and selected Route 17 as its recommended preferred route from an environmental land use perspective. ETT again considered the required criteria for selection and approval of a route, input from the public, the routing consultant’s recommendation, estimated cost, and engineering design and confirmed Route 17 as its preferred route. A more complete discussion of the evaluation and tables showing the data are included in the application.
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