County leaders took aim this week at the engineers of a massive airport construction project, saying the firm must share responsibility for an unexpected $1.5-million bill that came at the end of the project.

At its regular meeting Tuesday, the Orange County Board of Supervisors approved the change order for the construction of Terminal C and other improvements at John Wayne Airport, raising the total price tag to $127.8 million.

Airport director Alan Murphy told supervisors that the increase was caused by an “error or omission” by the project’s architect-engineer, which is San Francisco-based Gensler, according to the airport’s website. “We are in discussions with the [architect-engineer] on these issues,” he said.

A county staff report said the cost increase was due to “disruptions to workflow and labor inefficiencies” because of “defects, ambiguities, and omissions in the design, as well as numerous field changes.”

That description was itself ambiguous, said local resident Darrell Nolta.

“Disruption to the workflow and labor inefficiencies … what does that mean? That’s a very general term,” said Nolta. “I’d like you to define to the public … what [were] the disruptions to the workflow.”

Chairman John Moorlach responded that the overall airport improvement project was finished on time and $88 million under budget.

He also praised airport managers and the project’s main contractor, McCarthy Building Cos., for making sure the $1.5-million cost increase “was thoroughly documented and carefully reviewed.”

The original Terminal C contract, approved in 2009, was for $102 million. Since then, officials have approved 984 change orders totaling $25.5 million in added costs.

— NICK GERDA

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