Texas regulatory staff recommends approval of Oncor’s application for 138-kV line

Public Utility Commission (PUC) of Texas staff on Jan. 22 recommended that the PUC approve Oncor Electric Delivery Company’s application for the construction of the proposed 138-kV McKenzie Draw–Texaco Mabee Transmission Line Project.

As noted in the staff’s recommendation, Oncor last November filed its application, requesting to amend its certificate of convenience and necessity (CCN) to build and operate the new double circuit line within Andrews and Martin counties in Texas. The proposed project impacts only two landowners, and both were involved in the route’s creation. Both landowners have already entered into a transmission line route agreement with Oncor, thus only one route was proposed in the CCN application, staff added.

The facilities include construction of the new line connecting the proposed Oncor McKenzie Draw switching station, to be located in Martin County about 26.5 miles northwest of Midland on the west side of U.S. Highway 349, and Oncor’s existing Texaco Mabee 138-kV substation, located in Andrews County about 17 miles northwest of Midland.

“Based on the review of the application and the attached memorandum of Brandon Righter of the Infrastructure and Reliability Division, staff recommends that the commission approve the application for the construction of the McKenzie Draw–Texaco Mabee Transmission Line Project,” staff said.

Staff recommended Oncor be ordered to comply with certain reporting requirements and to follow the measures to mitigate construction impacts.

According to Righter’s filing, those measures include:

  • In the event Oncor or its contractors encounter any artifacts or other cultural resources during project construction, work is to cease immediately in the vicinity of the resource and the discovery is to be reported to the Texas Historical Commission
  • Oncor is to exercise extreme care to avoid affecting non-targeted vegetation or animal life when using chemical herbicides to control vegetation within the right of way (ROW)
  • Oncor is to minimize the amount of flora and fauna disturbed during construction of the line, except to the extent necessary to establish appropriate ROW clearance for the line

TPWD comments

In its Jan. 19 comments filed with the PUC, the Texas Parks and Wildlife Department (TPWD) recommended that if migratory bird species are found nesting on or adjacent to the project area, then they must be dealt with in a manner consistent with the Migratory Bird Treaty Act. The TPWD recommended excluding vegetation clearing activities during the general bird nesting season, March through August, to avoid adverse impacts to that group.

The environmental assessment (EA) that Oncor contracted URS Corporation to prepare in support of Oncor’s application to the PUC to amend their certificate of convenience and necessity, stated that “[s]ome small, low mobility species have the potential to be killed by heavy construction and maintenance machinery. These include several species of amphibians, reptiles, mammals, and if ROW clearing and construction occurs during the breeding season, the young of many species, including nestlings and fledgling birds.”

If clearing vegetation during the migratory bird nesting season is unavoidable, TPWD said it recommends that Oncor survey the area proposed for disturbance to ensure that no nests with eggs or young will be disturbed by operations.

To prevent electrocution of perching birds, the TPWD recommended using avian-safe designs that provide appropriate separation between two energized phases or between an energized phase and grounded equipment.

The TPWD also noted that the EA said, “One species with the potential to occur within the study area is the state-listed and designated as threatened by TPWD, the Texas horned lizard.”

The agency recommended avoiding disturbance of the Texas horned lizard, its burrows and colonies of its primary food source, the Harvester ant, during clearing and construction. The TPWD also said it recommends that a biological monitor be present during construction to try to relocate Texas horned lizards if found.

According to the EA, the TPWD last September documented one prairie dog colony within the study area and four more within one mile of the study area, and recommended surveys be conducted for their occurrence. No on-the-ground surveys have been conducted; however, no prairie dog colonies were observed during the aerial site reconnaissance, the TPWD added.

The agency also noted that previously unrecorded Black-tailed prairie dog towns may occur in the project area, adding that the Black-tailed prairie dog provides food and/or shelter for rare species tracked by the TPWD, including the Western Burrowing Owl.

The TPWD recommended that Oncor survey the selected route for prairie dog towns and avoid disturbance of prairie dog burrows during placement of the structures, ROW clearing, and line maintenance. If prairie dog burrows would be disturbed as a result of the proposed project, TPWD said it recommends that non-harmful exclusion methods be used to encourage the animals to vacate the area before disturbance and discourage them from returning to the area during construction.

If prairie dog towns would be disturbed as a result of the proposed project, the TPWD recommended that the burrows be surveyed for burrowing owls. If nesting owls are found, disturbance should be avoided until the eggs have hatched and the young have fledged, the agency said.

Among other things, the TPWD recommended that URS and Oncor prepare a mitigation plan to provide compensatory mitigation for those habitats where impacts from the transmission line cannot be avoided or minimized. That would include impacts to species and habitats covered under federal law, such as wetlands, and state resource habitat types not covered by state or federal law, such as riparian areas.