American Electric Power’s (NYSE:AEP) AEP Ohio Transmission Company (AEP Ohio Transco), in a March 1 application for a certificate of environmental compatibility and public need that was filed with the Ohio Power Siting Board (OPSB), said that it plans to build a new 138-kV electric transmission line from the proposed Macksburg substation south to the proposed Devola substation in Washington County, Ohio.
The Macksburg to Devola 138-kV Transmission Line Project, which is located in central Washington County, between Macksburg, Ohio, and Marietta, Ohio, is one component of the overall Southeast Ohio Area Improvements Program that will improve local service for customers, decrease power interruptions, and speed recovery of local service when outages occur, the company said.
The focus of the program is to rebuild the area’s aged 23-kV infrastructure into a 138-kV network and redesign the system to improve reliability for customers across the region, the company said.
The purpose of the proposed project is to provide additional transmission service to Washington County and to improve electric service reliability in the southeastern Ohio area, the company said. Much of the area is served by an extensive 23-kV distribution system, which will be retired and replaced with a new 138-kV transmission system, the company said.
The proposed project would provide two-way transmission service to the AEP Ohio Transco-owned Buell substation and Washington Electric Cooperative Inc.-owned South Olive and Highland Ridge substations, significantly improving service reliability to area customers, the company said.
The proposed project begins about 0.5 mile northwest of Macksburg at the proposed site of the Macksburg substation, located about 385 feet southwest of the intersection of Interstate 77 (I-77) and County Road 821, and extends generally south. The company added that the proposed project terminates about 2.4 miles southeast of Devola, Ohio, at the proposed site of the Devola substation, located about 0.57 mile north of the intersection of Colegate Drive and Mill Creek Road.
Between the proposed Macksburg substation and proposed Devola substation, the project connects to the proposed Buell substation – located about 1.1 miles east of Lowell, Ohio, and about 655 feet northeast of the intersection of Highway 60 and County Road 48 – and the Highland Ridge substation – located about 2.2 miles northeast of Devola, and about 900 feet south of the intersection of I-77 and County Road 8.
The proposed project is about 15.7 miles to 16.5 miles long, depending on the route selected; would be built using primarily steel monopoles; and would require a new 100-foot-wide permanent right of way (ROW), the company said.
The entirety of the preferred route from the proposed Macksburg substation to the proposed Devola substation is about 15.7 miles long, the company said, noting that that route begins at the proposed Macksburg substation and runs immediately south for about 2.96 miles, paralleling I-77 on the west side.
The route crosses over I-77, then continues south for about 1.97 miles, before crossing back over I-77. The route continues to parallel I-77 on the west side for about 2.98 miles before splitting just northwest of the intersection of County Roads 8 and 316.
The western branch of the route, the company added, runs southwest for about 1.9 miles before turning northwest and running to the proposed Buell substation, just north of Highway 60. The eastern branch continues south for about 1.2 miles, crosses over I-77, then continues south for about 2.13 miles until it connects to the Highland Ridge substation. The company also said that the route then crosses back over I-77, before continuing south for about 3.1 miles, then terminating at the proposed Devola substation.
The preferred route consists of Route 66 (the northern section) and Route 132 (the southern section).
The company added that the northern section was identified as the top-ranking route from a scoring process and has several positive characteristics, including:
- Low number of residences between 100 and 1,000 feet from the centerline, and a relatively low number of property owners within the ROW
- A low number of stream crossings and few impacts to riparian areas compared to all 129 routes evaluated
- The least amount of Ohio Historic Inventory (OHI) structures within 1,000 feet, and no National Register of Historic Places structures within 1,000 feet
The company said that the southern section was identified as the top-ranking route from the scoring process and also has such positive characteristics as:
- No residences within 100 feet and the fewest residences within 1,000 feet of the centerline
- Lowest acreage of woodlots within the ROW
- Fewest number of OHI structures within 1,000 feet
- Shortest overall length
Among other things, the filing also provided an estimate of the applicable intangible and capital costs for the preferred route, which has a total cost of about $27.5m.
The current project schedule calls for the project to be complete in 2021, according to AEP Ohio Transco.