The study, prepared by the Federal Railroad Administration, examined the proposed relocation's effects on air pollution, noise, vibration and other factors. It found no adverse consequences significant enough to block the project.

Eleventh Ward Ald. Nicole Lee said the timeline alone undermines confidence in the conclusion. The review was announced Oct. 26 and completed 11 days later, she said.

"We don't trust what they're doing," Lee said. "This was announced on October 26, and 11 days later they were done with it and found no significant impact? So we question what they put in that report."

The project would move Amtrak's railyard and maintenance facility from its current site at 14th Street and Canal Street to Bridgeport, a densely populated neighborhood on the city's South Side. The relocation is backed by Justin Ishbia, who is positioned to become the next owner of the Chicago White Sox and is leading the effort to clear the South Loop site for a possible new ballpark near the Chicago River.

Federal officials initially sought to approve the project without a more detailed environmental study, but reversed course after widespread opposition from community members and elected officials, including Lee, Sens. Tammy Duckworth and Dick Durbin, and others.

Ishbia and Amtrak issued a joint statement Friday praising the deeper review, which residents had requested after an initial September assessment they felt left out key details.

"We believe this deeper review process will provide the public with additional information about the need for the new facility and associated viaduct repair work, as well as the environmental impact of the project," the statement said.

Lee said the report raises more questions than it answers, pointing to the disparity between the current industrial site and the proposed location.

"A major industrial complex like this does not need to be moved from an industrial site where there are 30 residents within 500 feet to a densely populated residential area with 6,700 people, 1,100 kids and nearly 1,400 seniors," she said.

The study also notes that 17 viaducts would require repairs, adding construction activity, noise and potential dust to the neighborhood. According to neighbors, the air quality disruptions those repairs could cause were not included in the analysis.

"Something they left out of the study is PM 2.5, which is small particulate matter, which is one of the most dangerous contaminants to human beings," said Maria Lagiglio, a Bridgeport resident.

Ann Caruso, who also lives in the neighborhood, echoed the frustration.

"I'm tired of being treated like I don't have a brain up here, because I do and they're insulting my intelligence," Caruso said.

Residents will get another opportunity to weigh in at a public hearing next month, where Amtrak and Federal Railroad Administration officials are expected to attend.