Oakland, Calif. — Caltrans was awarded all the necessary environmental permits to safely remove Pier E3, the largest of the underwater piers at the Old Bay Bridge, with controlled charges. Experts have analyzed this method of demolition and agree it will significantly reduce impacts to the environment.
Caltrans’ engineers and environmental team have spent years working closely with resource agencies to determine the best method for demolition of Pier E3. That effort is culminating in permission from more than half a dozen regulatory bodies to use this implosion method on the largest of the Old Bay Bridge’s piers. The operation will remove the equivalent of a five story concrete building from the bay. The most recent permit from the United States Army Corps of Engineers is the final permit required to proceed with the implosion of Pier E3. The method has also received approval from:
- California Regional Water Quality Control Board
- California Department of Fish and Wildlife
- National Oceanic and Atmospheric Administration
- National Marine Fisheries Service
- The San Francisco Bay Conservation and Development Commission
- United States Fish and Wildlife Service
- United States Coast Guard
Fifteen years ago, when the new Bay Bridge project began, it was assumed that demolition would be done using traditional mechanical means. Now, more thorough analysis weighs the approved implosion method as a more environmentally friendly option.
Underwater controlled implosion technology has improved considerably over the past decade. Today, there are controlled charges that quickly dissipate and do not generate harmful chemicals. Instead of months of using loud heavy machinery, the demolition will take only six seconds. Environmental experts suggest this quick timeline saves money, reduces disturbances to marine life, and lessens impact on the environment.
"We can take this pier out of the Bay using highly controlled, sequenced charges and have it down in seconds or we can spend years pounding piles with all kinds of construction equipment lining the Bay," said Chief Bridge Engineer, Dr. Brian Maroney. "This is clearly the least environmentally impacting method and we owe it to the Bay to do it.”
Numerous safety measures will be in place to protect the environment during all phases of the implosion, including:
- Marine Mammal Exclusion Zone;
- Marine Traffic Safety Zone;
- Monitoring of:
- Water quality
- Marine mammals
- Air quality
- Acoustic disturbances
These controlled charges will be underwater and will likely not be easily heard or seen by nearby motorists. However, as a precaution, the Bridge’s bike path will be closed to the general public, and the California Highway Patrol, in coordination with Caltrans, will temporarily stop traffic on the bridge. Additionally, a heavy protective mat will be placed on top of the pier during the operation to contain any possible debris.
Caltrans is working very closely with the following partner agencies to ensure safety of the public and environment during the operation:
- California Highway Patrol (CHP)
- Bay Area Rapid Transit (BART)
- United States Coast Guard (USCG)
- Contractor –Kiewit/Manson
The implosion of Pier E3 is planned for November 7, 2015. Use of this method to remove the other piers will require additional approval from the regulatory agencies.