JEFFERSON CITY, Mo. (AP) -- An Ameren Corp. subsidiary plans to try again to get Missouri approval for a high-voltage power line after changing its route and getting consent from the last remaining counties in its 480-mile path from Iowa to Indiana.
Ameren said Wednesday that it will apply later this month to the Missouri Public Service Commission to build the 100-mile section of the line that passes through the state's northeast corner before continuing eastward into Illinois.
The Mark Twain Transmission Project is one of several planned to bolster the regional electric grid by Midcontinent Independent System Operator Inc., a nonprofit transmission company serving parts of 15 Midwestern and Southern U.S. states and Manitoba, Canada. About three-fourths of the power capacity in its region comes from natural gas and coal, but the new power line is positioned to also accommodate potential new sources of wind energy.
The Missouri portion of the new power line has been delayed for years by legal and regulatory hurdles.
A court ruled in 2014 that Ameren Transmission Co. of Illinois could not bypass the regulatory requirements of the Missouri Public Service Commission. The commission granted Ameren conditional approval in 2016, so long as it later got local approval to string the power line across roads. But a state appeals court panel overturned that decision in March, ruling that various county approvals must come before state approval.
Ameren secured the last necessary local approvals Tuesday when the Schuyler and Adair county commissions granted their consent.
If it gets state approval, Ameren hopes to complete the $250 million Missouri portion of the project by December 2019.
The revised route seeks to mitigate the concerns of some landowners by generally following the right-of-way for existing power lines owned by Ameren Missouri and Northeast Missouri Electric Power Cooperative. Some landowners had expressed concerns about visual blight and diminished agricultural production or fears of potential health effects from exposure to high-voltage lines passing through new areas.
The legal battle over Ameren's high-voltage power line has served as a precedent for decisions regarding a separate plan by Clean Line Energy Partners to build a 780-mile-long line carrying wind power from western Kansas across Missouri and Illinois to Indiana.
Missouri utility regulators rejected the Clean Line project in August, because it didn't have consent from all of the counties it would cross. Clean Line has asked regulators to reconsider and, if that request is denied, plans to take its case to a Missouri appeals court.