WESTBROOK – Officials planning the replacement of the Cumberland Mills bridges say the project is not without significant challenges.

The Maine Department of Transportation hosted a public meeting on the project at the Westbrook public safety building Monday night. The east and west bridges spanning the Presumpscot River at Sappi Fine Paper are nearing the end of their useful life and need to be replaced.

Project Manager Ben Condon said the project was last presented to the public in 2004, but due to conflicts with Sappi, the project did not move forward. A 2009 inspection only confirmed that the bridges now must be replaced, he said.

Officials revealed at the meeting that three temporary 25 mph detour bridges are being considered for the project. They said a complete closure of the road is impossible because 15,000 cars traverse the bridges daily.

One detour would tie in to Main Street, while the other two options would be either upstream or downstream of the current bridge, according to Greg Edwards, of the Scarborough consulting firm Stantec.

All three options present challenges because of the landscape around the bridges. Officials said they have to consider the bridges’ proximity to Sappi, the Maine Medical Partners building on Harnois Avenue and The Elms Bed and Breakfast, which is on the National Register of Historic Places, when planning the detour.

Whatever the decision, Mayor Colleen Hilton expressed concerns about traffic impacts elsewhere in the city. She said she has received multiple calls from people worried about additional traffic on Route 302. She asked for a traffic light where Duck Pond Road meets Route 302, which she called a “dangerous and busy intersection.”

Condon said they are still looking at traffic patterns, but suggested installing a traffic light could be a separate matter altogether.

Hilton also asked whether the temporary bridge detour could later be converted into a permanent pedestrian walkway, citing the importance of the riverwalk. She said the city would not expect the state to bear the brunt of the cost.

Again, Condon was noncommittal, but said it would be hard to accommodate that.

Another public meeting will likely be held early next year when the Department of Transportation has more details in place. Construction is expected to start in spring of 2012 and last until the fall of 2013.