How is the Tunnel Built?

Construction on the tunnel shafts began in January 2018. 

The tunnel-boring machine will arrive at the site in numerous shipments throughout September and October 2018. It will be lowered into the tunnel in pieces and reassembled for operation. It will dig a tunnel 20-foot in diameter and approximately 200 feet below the surface, which is more than 18 stories below ground. The tunnel can store up to 55 million gallons of combined rainwater and wastewater when complete. It will actually bore a 22-foot diameter tunnel, it will later be finished with a 12-inch thick coating of concrete to prevent any water leaking in or out to the environment.

 

 

Construction Schedule

Working Shaft and Pump Station Shaft Excavation Start:

January 2018

Working Shaft and Pump Station Shaft Excavation Finish:

July 2018

   

Drop Shaft DS04 Support of Excavation Start:

April 2018

Drop Shaft DS04 Support of Excavation Finish:

August 2018

   

Tunnel Boring Machine Arrival and Setup:

September-November 2018

Tunnel Boring Begins:

November 2018

Tunnel Boring Finishes:

December 2019

   

Tunnel Concrete Lining Start:

January 2020

Tunnel Concrete Lining Finish:

August 2020

   

Tunnel Substantially Complete / Operational:

December 31, 2020

   

Final Completion:

March 31, 2021

   

Consent Decree Deadline:

December 31, 2020