Final demolition of piers from old Bay Bridge scheduled for Saturday

OAKLAND, Calif. (KGO) -- On Saturday, Caltrans will demolish the final two piers that held up the old eastern span of the Bay Bridge. It will affect drivers on Saturday and is already affecting those who use the bridge's walking and biking trail.

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Crews were still busy hammering away at the project, less than 24 hours away from the final implosion, to make sure it goes like clockwork.

"It won't be very loud and the whole process takes about five seconds, once the implosions begin," according to Dan McElhinney, chief district director for Caltrans.

The agency has already shut down the bike path and walking trail on the south side of the bridge while crews installed explosive charges on Piers 19 and 20.

The piers, buried deep in the bay mud, supported the old eastern span of the bay bridge. Once that span was torn down, the piers were no longer needed.

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Caltrans destroyed the first of them in September of 2015, about three years and one week before this final demolition. Once again, for safety, there can be no cars on the bridge during the blast.

"On Saturday, between 11 a.m. and 1 p.m., we're going to slow traffic with the help of the CHP so there's no traffic on the Bay Bridge," McElhinney said. Drivers should expect rolling closures lasting up to 30 minutes on I-80 eastbound and westbound approaching the Bay Bridge during those hours.

The expertly placed charges will cause the piers to collapse in upon themselves and steps are being taken to protect the sea life nearby. That includes federal, state and local animal experts monitoring the whole process.

Also, if you notice bubbles in the San Francisco Bay water near the piers, they are there to protect the fish. The bubbles are generated by giant compressors on barges. They will ring the piers with a curtain of bubbles during the explosion to reduce the shock wave that could hurt aquatic life.

In the meantime, four remaining piers will be used to created a 600-foot-long boardwalk out into the bay from the Oakland side and a smaller 140-foot-long boardwalk from Yerba Buena Island.

Those boardwalks are scheduled to be open to the public by this time next year.