In a unanimous vote Monday night, Princeton Council approved a revised agreement with developer AvalonBay that will allow demolition of the former Princeton Hospital building to begin, possibly as early as mid-September. The demolition will make room for AvalonBay’s 280-unit rental property, which has been in the works since August 2011.

Mayor Liz Lempert and Council member Heather Howard were not present at the meeting, at which several members of the public urged the governing body to delay voting on the agreement so they could review the revisions. But Council President Bernie Miller said Ms. Lempert and Ms. Howard had participated by telephone in a closed session that preceded the meeting, and expressed their support for approval.

The developer’s agreement was amended following court-ordered mediation between representatives of Council and AvalonBay. The developer had sued the town over the agreement that Council approved in April, a month after approving an earlier agreement. The second document called for additional testing following the recommendations of an environmental consultant when the presence of two former incinerators at the hospital site was revealed.

Last month, Mercer County Superior Court Judge Mary Jacobson ordered the town and the developer to meet with a mediator to resolve their dispute over whether Council was legally able to require the extra testing. A town can require additional testing of a developer beyond regulations set by the state, but only if there is an ordinance in place. Princeton does not have such an ordinance.

While the new, mediated agreement calls for less environmental testing than the Council had required, municipal attorney Trishka Cecil advised the governing body to approve the measure rather than risking further litigation by AvalonBay, which she said could likely result in no environmental testing at all.

Under the new agreement, AvalonBay will drop the lawsuit and follow the environmental protocols recommended in the report completed last March, before the Council voted to amend that document. The developer will test the medical incinerator floor drains and related piping, and any ash found during demolition. They will test for metals but not PCBs. Instead of sampling exterior soil and soil below the former incinerator room, the company will stockpile that soil for use in such locations as underneath asphalt. Should any discharge be detected, the soil will be taken from the site.

The company will also bring clean fill topsoil for grass, landscaping, and pervious surfaces, according to the agreement. The topsoil will be four inches deep and cover approximately 65,000 square feet of the development. Twelve inches of topsoil will be used in a community garden. AvalonBay has also agreed to provide five air monitors during the crushing of concrete, but will not do any sampling of concrete that is being re-used at the site.

Among those residents asking questions and urging Council to hold off on voting was Paul Driscoll, who said that many neighbors affected by the decision are out of town in August. “Have you done everything you can to ensure the safety or our citizens?,” he asked, continuing, “This is the biggest demolition in Princeton history. People need to be involved.” Lytle Street resident Linda Auerbach questioned whether AvalonBay knew about the presence of the incinerator or the hospital failed to inform the developer before the sale.

Resident Sam Hamod told Council that he appreciated their work. “But remember this, you represent the residents of Princeton, not AvalonBay. I know you want to be fair to them, but you also have to be fair to us and to yourselves.” Another resident expressed concerns about potential contaminants that could be released when the hospital building’s chimneys are demolished.

Council attempted to answer questions posed by the public before stating, one by one, why they were choosing to approve the revised agreement.

“We’ve gotten a pretty good deal,” said Jenny Crumiller, explaining that AvalonBay was willing to compromise now but might not be later if the decision was delayed. Patrick Simon concurred, saying, “My assessment is that it accomplishes substantively everything we asked AvalonBay to do.” Council member Jo Butler commented, “If you’re really interested in public safety, you have to see that we had to make a deal.” Mr. Miller said, “In case there is any doubt, foremost was the protection of the health and welfare of the residents and the future residents of Princeton.”

Following the vote, AvalonBay vice president Ron Ladell said he was pleased at the decision. “We’re eager to move forward,” he said.

Municipal staff members met with AvalonBay representatives Tuesday afternoon to discuss the schedule for demolition. According to the town’s engineer Bob Kiser, the developer will begin to remove asbestos from the roof area later this week, and the process will take up to four weeks. Following that sometime between the middle and end of next month, demolition will begin.