East Lyme — AT&T has filed a formal application with the state Siting Council for approval to install a cell tower off Boston Post Road that would replace a tower near The Orchards subdivision.

The proposed 194-foot-tall monopole tower on an approximately 7-acre parcel at 351A Boston Post Road would provide service for both AT&T and T-Mobile.

AT&T has ruled out a potential site on Ancient Highway, as well as more than 30 alternatives, the cell company said in its application for a Certificate of Environmental Compatibility and Public Need.

The Siting Council, which determines the placement of cell towers within communities, said it will schedule a public hearing on the proposal to be held later in town.

The council is also seeking comments from the town on its location preferences by Nov. 6, according to a letter from the council to the town.

AT&T said in its application that it is seeking the replacement tower to maintain service, once its lease for a 150-foot-tower, built in the 1980s off Scott Road, expires at the end of 2016.

AT&T had previously filed technical reports with the town that explored both the 351A Boston Post Road Site — a wooded parcel with a single-family home — and another site on Ancient Highway as locations for the cell tower.

At a public information session in July, AT&T representatives said they were also looking into the site of the Gateway Commons development.

But AT&T has determined the Ancient Highway and Gateway sites are not feasible, after the Mohegan Tribal Historic Preservation Office said a tower at those sites "would visually and adversely impact various ceremonial landforms," according to the application.

The cell company said in its application that it also rejected other sites for reasons including that they were unavailable, wouldn't provide adequate service, or would have significant environmental effects.

AT&T filed the application to the Siting Council with American Towers, a limited liability company in Woburn, Mass., that holds a lease with James A. and Bonnie L. DeCosta, the owners of 351A Boston Post Road.

k.drelich@theday.com

Twitter: @KimberlyDrelich