SAN FRANCISCO (KCBS)— Caltrans is looking for approval from the San Francisco Bay Conservation and Development Commission to conduct a test underwater implosion of one of the piers from the old eastern span of the Bay Bridge.

It’s the latest step in the ongoing dismantling of the structure’s cantilever section piers.

Dr. Brian Maroney, Caltrans’ lead bridge engineer, said the blast would send the concrete from the section above the mud line into the hollowed out portion of the pier below. He calls the process “cutting edge” and that it would be more cost effective and environmentally safe than typical alternatives like building cofferdams around each pier before taking them apart.

“By putting it down these cells; this is a really good place. I mean, we’re literally filling up the holes that are down 200 feet. It seems to me to be a win, win, win. Sometimes good old fashioned common sense is really a good idea,” Maroney said.

The conservation commission’s chief of permits, Bob Batha, says there’s a certain element of risk involved with the implosion plan.

“One of the most important questions is: ‘Has this been tried elsewhere in the United States or around the world?’ It has not been tried in a marine environment,” he said. “It has been done in a river environment in Washington, I believe, but it’s a very different situation in a river versus a Bay.”

Caltrans wants to do the test implosion in November. The conservation commission is expected to vote on the plan this summer.

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