Fences were being installed Tuesday along the perimeter of the old Princeton Hospital, in preparation for demolition of the building to make way for construction of a 280-unit rental apartment and townhouse complex. But AvalonBay, the developer of the site, has yet to sign the revised developer’s agreement passed unanimously by Princeton Council on April 8.

“We’re still waiting to hear back from them,” said Mayor Liz Lempert on Monday. “But they can do certain work on the property that doesn’t require the developer’s agreement.”

Municipal engineer Bob Kiser said Tuesday that the 1,900 feet of fence being installed at the site is permitted without the signed document. “They can also remove the six underground storage tanks on the site, and remove the asbestos from the inside of the building,” he said. “But for anything else, they need to sign the agreement. And we haven’t heard anything from them at all.”

Asked Monday whether the company plans to sign the agreement or take legal action against the municipality over the vote, AvalonBay vice president Jon Vogel declined to comment. He and fellow vice president Ron Ladell left the April 8 Council meeting quickly after the governing body voted for the revisions and did not answer questions.

The agreement passed by Council was reworked by independent licensed remediation professional Ira Whitman following airing of safety and environmental concerns by members of the community. The document requires additional environmental testing in the areas of soil sampling relative to a medical waste incinerator discovered to have been in the hospital at one time. The agreement also calls for testing of soil reuse areas, and under drains, sewers, septic tank components, and concrete that is crushed on site.

Mr. Whitman’s first recommendations were presented to Council on March 10. After he gave his revised report on April 8, AvalonBay attorney Robert Kasuba said the company will “do the testing required by state regulations and nothing more. I can’t be more clear about that.”

Mayor Lempert said there is no particular deadline for AvalonBay to sign the agreement. “I know they have told us repeatedly that they are eager to start, but we need to have the agreement in place before they can start and get the approvals. The demolition plan is something that would need to be specifically signed off on, and staff can’t do that without a signed developer’s agreement.”

In a related matter, a citizens’ group known as the Association for Planning at Hospital Site decided after the April 8 Council vote that they would not appeal a ruling by Judge Mary Jacobson against their legal request to remediate concerns about spot zoning, the environment, safety, and overburdening infrastructure.

“This is a hard decision,” the group said in a statement, “since the record clearly suggests an egregious example of spot zoning, cleverly directed by its beneficiary, the University Medical Center of Princeton … when built, people will wonder how this was ever allowed.” The statement adds, “We are encouraged by the increased understanding of complex environmental and demolition issues recently exhibited by Princeton Council. All of Princeton will pay the price of letting the remaining issues go unaddressed.”