TBM for Clearwater Project unveiled in California

April 16, 2021

The Los Angeles County Sanitation Districts unveiled the Herrenknecht tunnel boring machine (TBM) that will be used to bore the tunnel of the $630 million underground Clearwater Tunneling project on April 15.

The project will replace two aging wastewater pipes installed in 1937 and 1958. Currently, 77 of Los Angeles County’s 88 cities rely on the antiquated pipelines that take treated wastewater from the Los Angeles County Sanitation Districts’ Joint Water Pollution Control Plant, in Carson, to the ocean off of San Pedro’s Royal Palms Beach.

“This project has been a long time in the making,” said Cathy Warner, the Sanitation Districts’ board chair and a Whittier City Council member. “As Californians, we enjoy a great standard of living in large part due to the quality of our infrastructure. This project is an investment to maintain that standard of living and preserve the environment for our grandkids.”

In June, the TBM will be lowered down a shaft, where it will be positioned to begin its 11-km (7-mile), underground journey below the streets of the South Bay and Harbor Area. The project will replace those aging pipes — which are 2.4 m and 3.6 m (8 ft and 12 ft) in diameter, respectively — with one 5.4-m (18-ft) wide, pipe that can handle the water flow.

The Daily Breeze reported that the machine, which expands to the length of more than two football fields and will be operated by a trained crew, will move about 9 to 15 m/d (30 to 50 ftpd), five days a week. Yet, it won’t reach its south-facing coastline destination for three and a half years. With other work also needed to connect the new pipes to the existing ocean outfall with undersea pipelines, the entire project isn’t expected to be complete until 2027.

Planning for the project began in 2006 when engineers realized the old pipes could not continue functioning without a breach, especially serving what is still a growing population. The situation was especially complicated, though, as the condition of the pipes was nearly impossible to gauge due to the need to keep a constant flow of water.

The existing pipelines also were not built to current earthquake standards.

At Royal Palms Beach, the new tunnel will connect to the existing ocean outfalls. Work at that location will take about two and a half years to complete. Beach and parking access will remain open, with work scheduled from Monday through Friday.

More than 500 community meetings were held before the current proposal — which included some additional bends and turns in order to keep the boring almost exclusively underneath city streets and away from homes and other buildings — was approved on Nov. 28, 2012, by the Los Angeles County Sanitation Districts.

The virtual news conference also included beamed-in remarks from Los Angeles City Councilman Joe Buscaino, a Sanitation Districts board member, and Torrance Mayor Patrick Furey, who is board chairman for Sanitation District 5 and the South Bay Cities Sanitation District.



Related article search: