Ameren said that its unit, Ameren Transmission Co. of Illinois, has selected a final route for the Mark Twain Transmission Project, which involves a 345-kV transmission line and substation to be built in northeast Missouri.
The nearly 100-mile route, which would be nearly 100 percent co-located on existing right of way (ROW), has received assents from the commissions of the five counties in which the line would be located – namely, Adair, Knox, Lewis, Marion, and Schuyler counties, the company said.
The route includes construction of the Zachary substation adjacent to the existing Adair substation in Adair County, the company said, noting that the route would co-locate on existing ROW on Northeast Missouri Electric Power Cooperative’s 161-kV transmission line between Palmyra and Kirksville, as well as Ameren Missouri’s 161-kV line from Kirksville to the Iowa border.
"The final route was selected based on feedback from landowners and community members during the past several months," ATXI Chairman and President Shawn Schukar said in the statement, in part.
As part of the project, about 59 miles of Northeast Power's 161-kV line would be completely rebuilt, Ameren said, adding that ATXI would remove the current wooden H-frame transmission facilities and replace them with new steel structures, the vast majority of which would be monopole in design. ATXI would pay for the poles, insulators and hardware, Ameren said.
Northeast Power CEO and General Manager Douglas Aeilts said in the statement that due to the age of Northeast Power's current 161-kV line, it would need to be replaced within 10- to 15 years at a cost of about $30m.
"Working with ATXI on this co-location project allows Northeast Power to save a significant amount of money while enhancing the reliability of our transmission system,” Aeilts said, in part.
Ameren noted that ATXI would rebuild Ameren Missouri's line between Kirksville and the Iowa border. Landowners living along the existing Northeast Power and Ameren Missouri lines would benefit from less burden on farmland – due to the reduced number of poles and the elimination of guy wires and anchors – as well as new easement payments, the company said.
According to the project’s webpage, the project is necessary to promote grid reliability; relieve congestion to the energy grid; meet local energy needs; and promote renewable energy.
ATXI will file, in mid-September, for a certificate of convenience and necessity for the project with the Missouri Public Service Commission, and hopes to receive an order of approval from the commission in 1Q18, Ameren said in its statement.
ATXI expects to invest about $250 million in the project, which is scheduled to be placed in service in December 2019, Ameren said.