BRUNSWICK – For Steve and Kristen Fortier, the thought of a Downeaster layover and maintenance facility being built in their backyard is a nightmare.

They’ve heard the clang, rumble and roar of freight trains for years near their home on Bouchard Drive. Sometimes the trains idle on the tracks overnight while crew members sleep in nearby motels.

“It’s not something you want in your backyard 365 days a year,” Steve Fortier told a panel of state officials Thursday night.

The Fortiers were among about 150 people who attended a public forum in the Town Council chamber at Brunswick Station on a controversial proposal to build a $5 million layover and maintenance facility in town next spring.

The New England Passenger Rail Authority, in partnership with the Maine Department of Transportation, is preparing to extend Amtrak service north of Portland, with stops in Freeport and Brunswick, in late 2012. At least three trains would travel to and from Brunswick each day.

The initial site proposed for the layover facility is a strip of land amid residential neighborhoods off Route 1 in West Brunswick. It runs along the north side of the tracks, between Church Road and Stanwood Street.

In the wake of homeowners’ outrage, state officials now are considering a few other sites and opening up the review process to ensure better public participation.

“We are pulling back and we are going to listen to you,” said Transportation Commissioner David Bernhardt. “You are the customers.”

Another site under consideration is the Brunswick Industrial Park, also in the western part of town, on uneven terrain where the public works department dumps snow.

One site that several townspeople said was better suited for a layover facility and long-term passenger parking is on Farley Road in East Brunswick, near the Cook’s Corner shopping area. They said it has few residential neighbors and would address concerns about lack of long-term parking near the downtown train depot.

The layover facility would include a 40,000-square-foot industrial shed large enough to hold three trains, said Patricia Quinn, executive director of the rail authority. Each train would include an engine, several cars and a control car.

Wherever the layover facility is built, the state plans to buy the land and pay for construction using transportation bonds, Bernhardt said.

The land near Church Road is owned by Pan Am Railways. If the rail authority decides to build the layover facility elsewhere, the state still plans to buy the land near Church Road because it owns the tracks there, Bernhardt said.

The rail authority wants to build a layover facility in Brunswick to service the Downeaster there instead of in Portland, where the trains are stored and worked on outside, Quinn said. There is no plan at this time to service other trains at the layover facility, she said.

State Sen. Stan Gerzofsky, D-Brunswick, organized Thursday’s meeting to address constituents’ concerns about the layover facility.

Many residents complained that they and town boards seem to have been shut out of the review process so far.

“It’s going to be collaborative,” Gerzofsky assured them at the start of the meeting. “We’re all going to be in this together.”

Gerzofsky said he will hold a second public forum on the layover facility on July 14 at a time and place to be determined.

The rail authority has hired Parsons Brinckerhoff, a Boston consulting and engineering firm, to review possible sites for a layover facility, Quinn said. It will assess the various environmental impacts and related costs of developing each site and recommend the one that best suits the needs of residents and of Amtrak.

Fourteen residents near the Church Road site, including the Fortiers, filed a lawsuit earlier this month in Cumberland County Superior Court asking a judge to vacate a zoning variance that town officials granted for the layover facility in April. The town’s lawyer has said that the federal government has authority over the project, so the variance is moot.

Neighbors of the Church Road site questioned why the town would have no say over a building surrounded by more than 100 homes that would be 650 feet long — nearly the length of two football fields — and 40 feet tall at its roof peak.

“We are enthusiastic about the Amtrak expansion to Brunswick,” Maurice Bisson, one of the neighbors who filed the lawsuit, told state officials Thursday. “We are not opposed to trains passing by. However, we believe strongly that this is the wrong location for a train layover and maintenance facility.”