ROCHESTER - Mayo Clinic's $5 billion downtown expansion cleared its first major hurdle Monday after the Rochester City Council accepted an environmental review of the project detailing some of the impacts the project will have on the area over the next few years.

The review was released earlier this year and is more than 360 pages long. But it's a necessary step before Mayo officials seek permits.

"There are still going to need to be additional approvals outside of this," said Irene Woodward, the city's Community Development director.

Woodward pointed out the review doesn't mean the city has signed off on all of the project, but it does show how Mayo plans to tackle some issues, such as installing specialized glass to prevent birds from flying into buildings. The review could also change if Mayo changes aspects of the project.

The downtown expansion is set to build out close to 20 acres and significantly change Mayo's campus — Annenberg Plaza is set to become a street again as Mayo constructs five new buildings by 2030. Mayo officials plan to start demolishing existing structures like the Ozmun building complex and the former Lourdes High School this fall, making room for clinical and logistical buildings respectively.

Construction will likely get underway in earnest next year as Mayo finalizes building designs and secures local and state permits.

No state agencies have objected to the environmental review so far, according to Woodward. Some have sought more information on wastewater and stormwater practices as well as geothermal energy needs as Mayo potentially hooks into a planned geothermal district downtown.

Council members voted 6-1 to accept the review, though several council members expressed concerns over air quality and traffic patterns, among other issues. Council Member Mark Bransford said he worried over bike lanes near the Gonda building as part of the project, while Norman Wahl and Kelly Rae Kirkpatrick urged the city to provide as much air quality data as possible once construction begins.

City officials say there will be near-real time air quality measurements as the project gets underway, while the city has to sign off on traffic changes as the expansion gets underway.

"There will be some back and forth," city engineer Dillon Dombrovski said.

While city officials say they'll be flexible with Mayo's engineers on traffic solutions, any issue that becomes deadlocked will go to the council for final approval.

The lone dissenting vote, Molly Dennis, said there hasn't been enough public meetings or discussion outlining everything in the review.

"There's just too much unknown," she said.

City officials said Mayo has met with nearby neighborhoods and business groups over the past few months, with more planned once the project takes off.

Council Member Patrick Keane said continued questions shouldn't be surprising as both Mayo and city engineers react to design plans.

"This just says we've gone through the planning questions, we've put the things out on the table ... we think we know what's in front of us," he said. "In that way, I think this has been successful."