Transportation officials in Contra Costa County, California, say they may have to scrap a bridge building project already underway if government regulators don’t accept their plan to reduce impacts on fish.
The contractor for the Benicia bridge has been barred from the site in the Carquinez Strait since November, after construction noise killed fish. Several fish species live in the strait, including salmon and endangered Delta smelt.
Rod McMillan, an engineer for the Bay Area Metropolitan Transportation Commission, told the Contra Costa Times every day of delay adds $100,000 to $200,000 to the project’s price tag.
The commission and Caltrans have devised a plan to have the contractor work only during slack tide and use construction techniques that reduce impacts on fish through mid-May — the end of the migration season. The techniques include pumping an air bubble curtain around the piles and employing outer steel casings to absorb the sound waves. Crews would drive piles without these restrictions from May 15 through October.
The contractor must drive 150 piles into bedrock by fall.
“I can’t believe things have gone this far,” Mark DeSaulnier, a MTC member and Contra Costa County supervisor told the Times. “It’s been surreal. The staff at these agencies are obviously trying to do their jobs based on a narrow focus, but now we need people above them to take a bigger perspective.”
Under the proposal, the fish dispute, including delays, would cost $164.6 million. But if regulatory agencies require bubble curtains and isolation casings throughout pile driving, extra years and millions of dollars would be added to the project, Caltrans officials say.
The bridge’s price tag has tripled to $904 million, and the fish aren’t the only problem. Unexpected rock layers, collapsed bores and a design flaw in the way the bridge attaches to piers will add $88 million.