For the past two years, former Ada County Commissioner Sharon Ullman was the public advocate of the Dynamis waste-to-energy plant, with Commissioner Rick Yzaguirre quietly supporting her.

But not on Tuesday. Less than one month after Ullman left office, Yzaguirre joined Commissioners Dave Case and Jim Tibbs in the unanimous decision to terminate the proposed garbage-burning, electricity-generating plant at the Ada County landfill.

The vote came after several citizens took Yzaguirre to task for his previous support of Ullman and the project.

"Commissioner Yzaguirre, I think you were wrong to provide a shoulder on which a bully commissioner could lean ... without allowing us any say in the process whatsoever," Boise resident Ken Lamkin said at a public hearing, where the commissioners formally killed the troubled project.

Afterward, Yzaguirre defended his role and explained to the Statesman why he had faith in the project.

He noted that early on, Idaho's governor and congressional delegation endorsed the project and Dynamis CEO Lloyd Mahaffey.

The commissioners had reason to trust that the project was in good hands, Yzaguirre said. Mahaffey had been on Gov. Butch Otter's list of potential lieutenant governor candidates to replace Jim Risch when Risch went to the U.S. Senate in January 2009. Mahaffey also served on Otter's Idaho Economic Advisory Council.

After the project was approved, delays, complications and mounting concerns about its environmental impact led to a drawn-out public outcry.

"The support went away and the commissioners were left standing alone," Yzaguirre said.

Yzaguirre said he had hoped to repeat the success the county had with its methane gas-to-energy project, which generates about $250,000 a year for Ada's coffers.

"The economy was down. It was economic development with a local company based in Eagle, my home," said Yzaguirre. "I wanted it to work so bad."

The Ada County contract with Dynamis had been signed and the county had already spent $2 million when movement for a public hearing took hold.

"What could we do then?" Yzaguirre asked. "In my mind it was too far down the road."

As questions mounted, Yzaguirre put a lot of faith in the Idaho Department of Environmental Quality review of the project. But even that seemed to stall.

With concerns about litigation from Dynamis and from citizens, Yzaguirre said, he backed the decision in mid-November to send Dynamis a 90-day notice to repay the $2 million.

"We were not going to get the $2 million, that became very clear," Yzaguirre said. "So does it make sense to end it or does it make sense to go to court?"

This month, the three commissioners decided to end it. The board approved an agreement Tuesday that "cancels" the project, releases Dynamis from the $2 million obligation to the county and releasing Ada County from "all potential claims from Dynamis of up to $70 million," Case said.

Dynamis told the county that it had invested $10 million in the project and stood to gain tens of millions in future revenues, Case said. "Cutting a deal was “the best possible solution to protect the county and taxpayers from liability," he said.

Yzaguirre agreed.

"I am just glad to move on," he said. "I think we all are."

Cynthia Sewell: 377-6428, Twitter: @CynthiaSewell