Barring the predicted paralyzing effects of the latest winter storm, a group of residents who live in the neighborhood of the former Princeton hospital site will be in a Trenton courtroom on Thursday to try and overturn the Princeton Planning Board’s approval of developer AvalonBay’s revised plan for a 280-unit rental complex.

The eight members of a group known as the Association for Planning at Hospital Site LLC filed an appeal to the Planning Board’s decision last October, naming the municipality, Planning Board, the Mayor, Council, and AvalonBay as defendants. While one of the five counts, having to do with spot zoning, was rejected by the judge in a preliminary hearing, the other four, focused on concerns about density, infrastructure, the environment, taxes, and how demolition will be carried out, are still active.

“What is very important to make clear to the public is that we are in no way opposed to development,” said architect Evan Yassky, one of the plaintiffs in the suit and a neighborhood resident for the past 17 years. “We encourage it. We don’t want to see that building remain as a deteriorating hulk. We’re just looking for responsible development. We feel that it should be in keeping with the existing fabric of the town, and we want environmental issues to be thoroughly addressed. Public safety and welfare are our first priorities.”

After AvalonBay’s first application was voted down by the Planning Board, the company appealed the decision to the courts. Last April, the town entered into a consent order with AvalonBay to suspend the litigation and allow the developer to submit a revised plan addressing residents’ concerns about density and other issues. The Planning Board approved the revised plan 8-1 last July.

Members of the residents’ group question the interpretation of the consent order. “The environmental issues are very complex. In the second application, our government was misled into believing the consent order restricted questioning on environmental topics, and this was conveyed to the public,” said architect Areta Pawlynsky, one of the plaintiffs in the lawsuit. “But in fact, it said that no new environmental submissions would be required of AvalonBay.”

Mayor Liz Lempert and AvalonBay vice president Jon Vogel declined comment for this article. But Planning Board attorney Gerald Muller said he is confident that the municipality will prevail. “We’ve laid out the whole case and briefs,” he said. “We think we have a very strong case, and we’re hopeful.”

The Association for Planning at Hospital Site LLC is not the first citizens’ group to challenge AvalonBay. Last year, Princeton Citizens for Sustainable Neighborhoods was a vocal presence during public hearings and presentations by the developer, but the group ceased its protests when the revised plan was approved. The newer group began by meeting in residents’ living rooms, with Ms. Pawlynsky and her husband, Yaron Inbar, as “the most powerful force in creating and galvanizing us,” said Mr. Yassky. “They were instrumental in tying people and pieces together.”

Those concerned about AvalonBay’s plans are not limited to the eight plaintiffs, Mr. Yassky added. “When the suit first went in, the plaintiff was the organization,” he said. “But the judge in the December hearing asked that the plaintiff be changed from that entity to individual residents. So the eight are the eight that were willing to have their names on the lawsuit. But overall, there are 70 to 100 people who have expressed their support and donated time and money to the cause.”

Several members of the group have spoken out at recent meetings of Princeton Council, expressing particular concerns about the discovery of an incinerator room inside the hospital building. While Mr. Vogel contended that the incinerator, which is no longer on the site, was used for burning medical records, the company agreed to monitor the room by videotaping while evidence of breaks in the drain are looked for. The Council voted to hire an independent licensed remediation professional to be part of the demolition process.

Hospitals routinely flushed toxic chemicals and radioactive materials down drain lines in the past, according to one resident who attended the January 27 Council meeting. “I think it’s cavalier to say we don’t have to worry about these things,” said Marco Gattardis, a cancer researcher. “I don’t believe them [AvalonBay]. And it’s a bigger issue than the incinerator itself. We need independent testing.”

The group has additional concerns about sewer lines. “The rezoning of the site was sold, in part, on the idea there was adequate infrastructure to support the high density,” said Ms. Pawlynsky. “What should have been known is that sewers backed up three times in 2002, and, in 2009, two more times in Henry Avenue homes. To us, that’s a big concern. The original hospital split its waste between the Witherspoon and Henry Avenue sewers. The current plan shows everything dumping into the Henry Avenue line. Who was supposed to upgrade that infrastructure? It wasn’t made a requirement of AvalonBay. One can only suppose that will be on the taxpayers’ shoulders.”

The residents have created a video, which is on their website http://aphsllc.com/wp/. The video was screened at a Witherspoon/Jackson neighborhood community meeting last week (see accompanying story). “We spent a lot of time making sure that video outlined all of the topics. What’s especially troubling is that there are so many,” Ms. Pawlynsky said.

The Thursday hearing is scheduled for 2 p.m. in courtroom four at 400 South Warren Street in Trenton.