DOUGLAS - The Zoning Board of Appeals, American Pro Wind LLC and their legal teams debated the conditions for approval of variances for hours last night, the major sticking point being minimum setback requirements for the 13 wind turbines.

Though no formal approval for the height and use variances was taken for Douglas Woods Wind by deadline last night, both sides were haggling over setback requirements, with the developers disagreeing with a proposed 1,000-foot minimum setback from the nearest residential structures.

While the developers have maintained that the turbines will be at least 1,000 feet away from the nearest home, they bristled at setting that as a minimum requirement that could be tinkered with during the site plan review process.

Ernesto Caparrotta, a consultant for the project, said the possibility of adding to that setback could kill the feasibility of the project. He said it has been determined that the 1,000-foot setback - nothing more - will allow for the placement of 13 turbines. Any fewer turbines would make the project financially unfeasible.

"It's a deal killer," Mr. Caparrotta said as the two sides negotiated.

Jay Tallerman, the town's special counsel for the wind farm project, said the town was in a unique position to be setting zoning code through variance conditions, since the town does not have an existing bylaw to regulate wind turbines.

"Because we are working with a blank slate, the community is designing code through a variance, and there has to be some discretion here," said Mr. Tallerman, saying he was uncomfortable binding the hands of the board in the site plan review process by setting something in stone in the variance conditions.

"It's only a deal killer if site plan changes something," he said

Rod Jané, a consultant with American Pro Wind, said the developers could not invest what could add up to millions of dollars in the coming months for the project without the variance and the support of the board.

Meanwhile, imposing immovable conditions did not sit well with abutters from Webster who have been attending all the public hearings and asking the board when is the appropriate time to address their setback concerns. The board had told them their concerns and evidence could be presented at the site plan review.

This is the second time the project has been in peril. Last month, the developers threatened to withdraw the project when board member Dan Heney said he was unwilling to appprove the variances without an independent peer review of American Pro Wind's studies. That peer review was finished and presented last week, and satisfied Mr. Heney's concerns.