MGM Resorts will take two key steps on Monday as it seeks to break ground in 2015 on an $800 million casino in Springfield that's being billed as the largest single development in western Massachusetts history.

A monthlong public comment period officially opens on the casino's final environmental impact report, which it submitted to the state office of energy and environmental affairs earlier this month.

The Springfield City Council also hosts a working session Monday evening with casino officials to talk about the road ahead. It's the first formal meeting on the project since voters statewide overwhelmingly rejected a Nov. 4 ballot question to repeal the state's casino law, which would have effectively halted the MGM project and others.

Springfield City Council President Michael Fenton says he plans to lay out a series of public hearings the council will hold in 2015 on zone changes and site plan approvals the project needs to break ground, as hoped, in the spring.

He says the council also wants to get updated revenue estimates from the casino as it looks to see how best to spend the annual windfall the project is expected to bring to the city.

MGM, under a host community agreement reached with Springfield, is expected to pay the city, at minimum, $17.6 million each year and as much as $26 million, depending on how profitable its operations are.

"It's my intention to assure that we do not allow the lion's share of this revenue to be gobbled up by recurring expenses in the general fund," Fenton said. "This is a once-in-a-lifetime opportunity for our community and if we're really going to transform the place that we love, we have to do it through long-term investment."

The MGM project will take roughly 2½ years to build, putting the casino on track for a 2017 opening or later, assuming the casino breaks ground in the spring. Casino officials have said they hope to name a general contractor for the development by the end of the year.

"For almost three years we have been preparing to put shovels in the ground, and as of now we are on track, and moving full steam ahead," said Carole Brennan, MGM Springfield spokeswoman.

The environmental study runs more than 700 pages and focuses on the project's effect on city and regional assets, from traffic and transit systems to water and sewer infrastructure and historic buildings.

The project, which spans roughly 14.5 acres, is being built along Main Street in the city's downtown and contains a mix of properties included on the National Register of Historic Places.

Plans call for a "Casino Block" offering 3,000 slot machines and 75 gambling tables, a 250-room hotel and shopping, dining, meeting and office space and residential apartments. The "Retail Block" will include a bowling alley, retail and restaurant space and a cinema.

The project is one of three licensed by the state so far. Wynn Resorts is also developing a $1.6 billion resort casino in Everett, a city just north of Boston, and Penn National Gaming is spending $225 million to expand the Plainridge harness racing track in Plainville into a slots parlor.