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Ameren to build 95-mile transmission line through 5 northeast counties


JEFFERSON CITY, Mo. – Ameren (ATXI) Transmission Company of Illinois will construct a 95 mile electric transmission through five northeast Missouri counties to the Iowa border.

The line, known as the Mark Twain Project was issued a certificate of convenience and necessity (CCN) by the Missouri Public Service Commission in a 5-0 vote, but Ameren will have to get permissions from the counties before it can start construction.

“ATXI has shown a need for Mark Twain, qualifications to own and operate it, the financial ability to build it, the economic feasibility of building it, and the public interest that would be served by building it.  Notably, there is a benefit to Missouri ratepayers if this CCN is granted,” the commission said. “ATXI does not have assent from any of the counties through which Mark Twain would run. …ATXI must get assent from each county through which Mark Twain would run before the certificate becomes effective.”

The CCN was granted because the project is expected to promote grid reliability, relieve congestion, promote renewable energy, meet local load serving needs and provide downward pressure on customer rates.

The electric transmission line will run about 95 miles in length from the new Maywood Switching Station near Palmyra, Missouri. It will go through Marion, Shelby, Knox and Adair counties to the new Zachary Substation, located near Kirksville, Missouri.  The transmission line would then continue north through Adair and Schuyler counties to the Iowa border.

The transmission line is 345-kV line and is the result of a study conducted by Midcontinent Independent System Operator, Inc. (MISO) to determine transmission needs and design and implement a plan to meet those needs. The Mark Twain Project will meet 2 of the 17 transmission projects MISO identified to increase the overall reliability and efficiency of the regional transmission grid, meet public policy demands for renewable energy, and provide economic benefits in excess of the portfolio costs.