Dayton Power and Light (DP&L), a wholly owned subsidiary of AES Corporation, on May 17 filed with the Ohio Power Siting Board (OPSB) an application for a certificate of environmental compatibility and public need for the proposed West Milton-Eldean 138-kV Transmission Line Project, which involves the construction of a single-circuit transmission line within Miami County, Ohio.
The proposed circuit would ensure that adequate transmission system voltages are maintained in the northwest area of the DP&L transmission system under various outage conditions, as required to comply with the mandatory NERC reliability standards, DP&L said.
It was through PJM Interconnection’s planning process that the need for the proposed project was identified, the company said, adding that the Regional Transmission Expansion Planning (RTEP) contingency analysis showed that under the multiple contingency of DP&L’s Shelby-Sidney 138-kV Circuit and DP&L’s Miami-Eldean 138-kV Circuit, voltages would be below the minimum acceptable level per NERC reliability criteria at eight transmission buses.
That multiple contingency would effectively leave the northwest area of the DP&L transmission system without a 138-kV source, the company said, adding that the new 138-kV circuit would mitigate that situation and ensure compliance with the mandatory NERC reliability standards.
The proposed project would consist of the construction and operation of the single 138-kV circuit line for improved reliability of electric service for DP&L’s northwest area of their service territory, the company said, adding that some portions of the line would be underbuilt with a 12.5-kV electric distribution line where the proposed route is co-located with an existing overhead electric distribution line – primarily along public road right of way (ROW).
The project would originate at the existing West Milton substation, located just south of the village of West Milton in Miami County, Ohio (Union Township), DP&L said. The project would extend along the west side of West Milton – outside of the village’s limits – to a point south of the town of Ludlow Falls, then head east adjacent to State Route 55, north adjacent to Forest Hill Road, and then across agricultural land toward the northwest (Concord Township) until the route reaches the Eldean substation, located on Experiment Farm Road, DP&L said. Both the preferred and alternate route are 16.6 miles long, the company said.
The project is located predominantly in a rural and agricultural setting, but portions of the transmission line routes occur along road ROW where there are intermittent residences located in that rural setting, the company said. About 80% and 76% of the corridor review area –200 feet wide – for the preferred and alternate routes, respectively, are comprised of agricultural land, DP&L said, adding that much of the remainder of the land for both routes consists of open land, residential lots, pasture land and forests.
Impacts to agricultural land uses due to operation and maintenance of the project are expected to be relatively minor in light of the overall percent of crop land that may be removed from cultivation due to new transmission structures, the company said. No recreational land or activities are anticipated to be impacted by the project, DP&L said, adding that no adverse impacts to commercial or industrial operations and businesses are anticipated to result from the project.
The preferred and alternate routes are co-located with either road ROW or existing transmission line ROW (DP&L-owned) that accounts for 11.2 miles and 8.9 miles, respectively, of the total 16.6-mile lengths, the company said. One primary area of industrial land use consists of a rock quarry within an approximate 550-foot section of the preferred route, DP&L said, adding that a small summer camp facility consisting of sleeping cabins is located adjacent to the preferred route about 0.3-mile west of the West Milton substation.
The number of residences within 1,000 feet of the preferred route is 195, DP&L said, adding that 20 of the residences are within 100 feet of the route. There are 297 residences within 1,000 feet of the alternate route, 10 of which are within 100 feet, the company noted.
Through correspondence with the U.S. Fish and Wildlife Service (USFWS), only the federally listed endangered Indiana bat, the federally listed threatened northern long-eared bat, and two mussel species were identified as potentially being present in the project vicinity, according to DP&L. The mussel species, if present, would be limited to the Stillwater River, which would not be disturbed during construction, the company said.
Some forest areas, estimated at about 2.7 acres, may need to be partially or completely cleared for construction of either the preferred or alternate route, which could result in the removal of Indiana bat and northern long-eared bat habitat, the company said. DP&L noted that it would clear any trees during the winter season to avoid impacts to the Indiana bat. The Ohio Department of Natural Resources also provided correspondence stating that the same two bat species and two mussel species as noted by the USFWS, plus one mussel listed as a state species of concern and one threatened plant, may occur in the project’s vicinity, the company said, adding that impacts to all of those species are expected to be avoidable.
Among other things, the company also noted that one historic structure, no National Register of Historic Places (NRHP) sites, and no historic districts were identified within 1,000 feet of the preferred route. Eight archaeological sites were recorded within 1,000 feet of the preferred route, and one cemetery is located within 1,000 feet of the preferred route near the West Milton substation, according to DP&L.
Further research and possible field investigations will potentially be undertaken in specific areas along the preferred route – pending consultation with the Ohio Historic Preservation Office, DP&L said. Formerly discovered archaeological sites and new sites can typically be avoided through strategic transmission structure placement and planned access road placement or mitigation measures, the company said, adding that certain areas may also be excluded for construction equipment in order to prevent soil surface disturbance, if warranted.
According to the filing, the preferred route has a total estimated cost of about $9.9m, while the alternate route has a total estimated cost of $10.2m.
According to the project’s schedule, construction is set to occur from June 2021 to May 2022.