So what happens now?

The ambitious, $630 million, multiyear Clearwater Tunneling Project had made nearly flawless progress since launching in 2021, but is now stalled for an undetermined amount of time, officials said Thursday, July 10 — the day after a tunnel collapse brought everything to a halt.

A portion of the tunnel, which has been more than a decade in the making, collapsed around 7:45 p.m. Wednesday, about five to six miles from the only access point — temporarily trapping more than two dozen workers. The collapse has prompted officials to look into what caused it and paused construction of the tunnel, which is intended to to move wastewater from Carson to San Pedro.

“The tunnel operation is on hold,” said Maria Rosales-Ramirez, spokesperson for the Los Angeles County Sanitation Districts and the Clearwater project.

The investigation into what happened launched immediately, she said, but there is no timeline into when that will be completed.

But county Supervisor Janice Hahn, who represents the area and is also on the board of the Sanitation Districts, said in a Thursday statement that officials will work to ensure a tunnel collapse doesn’t occur again.

“As the sanitation district we will be looking into exactly what caused this,” she said, “and will do everything we can to prevent anything else like this from happening again.”

Before the collapse, the tunneling was about a mile away from its final destination at Royal Palms, at the beach in San Pedro, and was on pace to be finished by the end of this year. Once the tunnel is complete, more work could be needed, with the entire project set to conclude around 2029, Rosales-Ramirez said.

But that timeline has been put into doubt: A completion date for either of those events remains an unknown, Rosales-Ramirez said.

The Wednesday evening collapse, meanwhile, may have occurred suddenly — but it also hearkened to the project’s early days, when the community expressed numerous concerns.

When the massive Clearwater project initially rolled out, in fact, it caused no shortage of angst among residents, businesses and schools at the time.

The ambitious plan — constructing a web of tunnels deep under streets, winding through developed residential and commercial areas throughout the heavily populated region — was needed to carry cleaned and treated wastewater from the Joint Water Pollution Control Plant, in Carson, to the ocean off of Royal Palms Beach in San Pedro. It’s intended to replace two existing and antiquated underground pipes built in 1937 and 1958, which currently serves more than 5 million people from the South Bay to the Antelope Valley. The main workplace site is east of the 110 Freeway and north of Pacific Coast Highway.

“People were concerned at first about the stability of the earth and the cliffs at Royal Palms,” said Diana Nave of San Pedro, who has long been active in the leadership of the Northwestern San Pedro Neighborhood Council.

But the Clearwater and sanitation representatives, she said, were “very good” about fanning out into the community and returning as often as needed to explain the project to community groups and answer questions.

Eventually, the project got off the ground and ran seamlessly — until Wednesday.

The collapse, nearing what was to be the final lap toward Royal Palms Beach, resulted in 31 workers being trapped.

The workers were trapped for more than an hour and the water was up to their mid-thigh, said interim Los Angeles fire Chief Ronnie Villanueva; they were all rescued by 9:15 p.m. The collapse occurred deep under the tunnel as it approached its final lap deep under Western Avenue just north of the beach.

It was a rescue effort that rolled out seamlessly, speakers said late Wednesday night.

“These workers are highly skilled men,” L.A. Councilmember Tim McOsker, whose district includes San Pedro and Wilmington, said about the trapped workers. “This is a highly technical, difficult project and they knew exactly what to do. They knew how to secure themselves; they knew how to get to the (vehicle) to get them back.”

The Clearwater project, meanwhile, was first approved in 2012 and prompted a widespread public outreach process to explain and reassure residents about the project.

Several in-depth environmental and safety studies looking at the safety and other impacts were also done as part of the regulatory requirements leading up to the project.

And the project, officials have said, is critical.

The Sanitation Districts, according to its website, treats about 400 million gallons of water per day — “enough to fill the Rose Bowl nearly five times a day.”  The agency’s infrastructure includes 1,400 miles of sewers, 49 pumping plants and 11 wastewater treatment plants. About half the wastewater in the county goes through those systems.

But not all the infrastructure is in great shape.

And currently, 73 of Los Angeles County’s 88 cities rely on the existing antiquated pipelines — which exist on two major earthquake faults — to take more than 260 million gallons of treated wastewater from the plant to the ocean.

The major part of the Clearwater project’s work — the actual tunneling – got underway in 2021 to replace the old pipes, which are 8 feet and 12 feet in diameter; the new ones are 18 feet wide each. A shaft at the Joint Water Pollution Control Plant was being constructed with reinforced concrete walls 70 to 160 feet deep.

The tunnel is being created using a giant boring machine, designed and made in Germany for this specific project, that travels below the streets of the South Bay and Harbor Area.

The new tunnel the mammoth machine digs is between 50 and 460 feet below the surface, depending on the overlying topography. At the beach, the tunnel will be 30 feet below the surface.

Assessments were still being made on Thursday as to what caused the issue and what would be needed to relaunch the work.

Doug Epperhart, president of the Coastal San Pedro Neighborhood Council, said he expects the investigation to be a long one — and that the collapse came as a surprise.

“We’ve been boring tunnels under L.A. for, it’s got to be, 20 years now,” he said, adding that the search into what could have caused the incident will be extensive and meticulous.

Clearwater officials gave annual updates to the neighborhood councils about the project, he said, and early concerns were fairly short-lived.

“They were good about getting out and talking to people about it,” Epperhart said. “We’ll see what they come up with.”