Limestone Ridge Project

Ameren Transmission Company of Illinois (ATXI) in collaboration with the Wabash Valley Power Alliance (WVPA) is constructing a new, approximately 15 mile 138 kV transmission line and state-of-the-art- substations to improve energy reliability for local communities in Southeast Missouri. The new line will connect two new substations in Perry and Cape Girardeau Counties. Approximately 65% of the new transmission line will be co-located along the existing Wabash Valley Power Alliance right-of-way. The proposed in-service date for the project December 2023.

In late 2021, Ameren Transmission Company of Illinois (ATXI) and our partners submitted an application to the Missouri Public Service Commission (PSC) for a Certificate of Convenience and Necessity for the Limestone Ridge Project. The PSC has granted ATXI a certificate of convenience and necessity (CCN) for the project, which will connect two substations in Perry and Cape Girardeau counties. ATXI expects to invest $40 million in the Limestone Ridge Project to provide additional capacity for the region’s energy infrastructure. Landowner easement negotiations will begin with impacted landowners in early 2022 with construction processes anticipated to start in early 2023. The Limestone Ridge Project has a proposed in-service date of December 2023.

Project Schedule

All items shown are pending regulatory approvals. Schedule is subject to change.


Data Collection

Collect digital & field data
Public engagement
Route development


Permitting and Design

Preliminary engineering
File Certificate with PSC
Certificate reviewed by PSC


Surveys and Real Estate

Field surveys
Real estate acquisitions
Engineering and permitting
Preconstruction activities



Project complete in December


In collaboration with Wabash Valley Power Alliance (WVPA), Citizens Electric Corporation and Ameren Missouri, Ameren Transmission Company of Illinois (ATXI) is proposing to construct a new, approximately 14-19 mile 138kV transmission line and state-of-the-art substations to improve energy reliability for local communities in Southeast Missouri. The new line will connect two new substations in Perry and Cape Girardeau Counties.
Our project team reviewed all comments collected during the virtual Community Representative Forums, Virtual Public Meetings, Telephone Public Meeting, Virtual Open Houses, email, mail, and phone calls. These comments were considered as we used our routing criteria to determine the Final Proposed Route. The Final Proposed Route addressed landowner comments and engineering requirements, maximized utilization of Opportunities, and minimized impacts to Sensitivities.
The Limestone Ridge Project will improve energy reliability, provide additional energy support to local manufacturing facilities and allow for efficient future expansion of the transmission grid. The proposed in-service date for the project is December 2023.

ATXI will seek feedback and input from the public through a series of public engagement events (summer – fall 2020) before submitting a route and application for a Certificate of Convenience and Necessity to the Missouri Public Service Commission in Q1 2021. The project is proposed to be in service by December 2023.

Limestone Ridge Project project schedule

After listening, reviewing and considering input received from landowners, community members, interested agencies and local officials, Ameren Transmission Company of Illinois (ATXI) and our partners have selected and filed a Final Proposed Route. View the interactive map [hyperlink to map] to see the Final Proposed Route.

Corridors and routes are developed considering defined routing criteria. The goal of the routing process is to take advantage of Opportunities while understanding and minimizing impacts to Sensitivities and adhering to technical guidelines.

The routing process starts with a large study area, which is then narrowed into wide corridors. Preliminary routes segments (more narrow) are then developed within the corridors using routing criteria. Stakeholder and community input is sought throughout the process. The goal is to identify a final route that will balance minimizing impacts to Sensitivities, with the cost of building and maintaining a safe and reliable transmission line within the statutory requirements.

During the routing process, we contact regulatory and resource agencies to notify them of the project and seek input regarding resources which could potentially be impacted within the study area. As the routing process continues, we continue to engage these agencies regarding minimizing potential impacts, additional surveys, if necessary, and permits that may be required for construction.
Construction is scheduled to begin in early 2023 and will take approximately one year – completed by December 2023.

Limestone Ridge Project structure graphic

We anticipate using galvanized steel monopole structures. The structures will be approximately 100-160 ft. tall. We estimate 6-7 structures per mile with an average span range of 800-1,000 ft. between structures. The Limestone Ridge Project steel monopole structures will have 7-12 ft. diameter concrete foundations. The foundations will range from 30- 40 ft. deep, depending upon the soil conditions.

Trees can interfere with transmission lines by posing a threat to the operational integrity of our system. For safety and reliability reasons, trees, tree limbs, and incompatible vegetation throughout the project area, mostly within the right-of-way, will be removed from the easement area during construction. Our standard easement will also give us the right to remove "hazard trees" – trees that are adjacent to the easement and have some structural defect such that they pose a potential risk to our transmission system. Even though our structures will, in some cases, be taller than the adjacent vegetation, we must also be mindful of the potential for storms to create windblown debris that could impact our facilities. We take our obligation to provide safe and reliable service to our customers very seriously, and work to make sure we are managing vegetation in a safe and responsible manner.

Transmission lines are similar to the interstate highway system in the way they will allow energy from generators to travel short or long distances, as needed, at any given moment. There are no restrictions on the type of energy that will flow on the new line. Ultimately, the energy carried on the line will be used throughout the regional grid, including by customers in the Project area and elsewhere.

The Limestone Ridge Project is not being proposed in Illinois due to several factors including:

  • The existing river crossings in the area are not capable of supporting a new transmission circuit. Rebuilding those crossings, or constructing and maintaining new crossings, would be very expensive.
  • The project benefits communities located in Missouri. It is fair for these facilities that create these benefits to be located in Missouri.
  • Developing a route in Illinois would pose its own challenges as most of the land adjacent to the river is also forested and/or within a floodplain.

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(573) 232-3003

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Limestone Ridge Project
45 S Minnesota
Cape Girardeau MO 63703

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