Tunnel Project Nears its Start

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Water district personnel inspect the bluff top tunnel, which will be enlarged for easier access and stabilization.
Water district personnel inspect the bluff top tunnel, which will be enlarged for easier access and stabilization

Carl Goodwin’s professional expertise as a former project manager for the Mission Viejo Company means he’s well aware of what to anticipate from a five-year construction project.

As early as next month, on a now vacant corner at Fourth Avenue and Virginia Way in South Laguna, a $70 million sewer tunnel project is due to get underway. There are homes on three sides of the property and Goodwin’s Florence Avenue home is a few doors away.

While the South Coast Water District project has undergone years-long environmental and planning reviews and public hearings, Goodwin still expresses anxiety about the start, now that it’s finally here. “We don’t know what it’s going to be like,” said Goodwin, 70, who still works as a financial consultant from the home he shares with his wife, Kathy.

District General Manager Andy Brunhart with a rendering of how the tunnel is expected to look.
District General Manager Andy Brunhart with a rendering of how the tunnel is expected to look.

To avoid the noise of truck traffic, debris conveyors, a crane and drilling rig, the couple is considering renting and vacating the neighborhood where they’ve lived since 1999. “If it’s bearable in the first year, then we are home free,” Goodwin predicted.

The district-owned lot sits midway along the two-mile-long ocean bluff tunnel. Built 60 years ago, the tunnel contains a sewer that relies on gravity and now carries 1 million gallons of wastewater per day to a treatment facility in Aliso Canyon. The district serves 35,000 residents from South Laguna to San Clemente.

To both stabilize deterioration in the tunnel and create an emergency back-up sewer line, district officials plan to enlarge the shaft and install a new 24-inch line, all beneath the multi-million dollar ocean-facing homes between Three Arch Bay and Camel Point. All but two of 194 property owners granted the water district easements 60 to 70 feet beneath their homes. The last two easements were obtained by eminent domain, said Andy Brunhart, the district’s general manager, who took questions last week before the project commences at a sparsely attended open house.

Access to the existing tunnel will be reached from a new shaft beneath Coast Highway that starts at the Fourth Avenue lot. Excavation will progress by seven to eight feet per day, including some work by hand, and will fill four to seven trucks a day, said principal engineer Karl Francis.

“Very likely the noisiest part of the job is in the first three months,” Brunhart said.

To shield residents and homes in the immediate area from noise and dust, city officials imposed an array of conditions for permit approval pushed in part by a neighborhood advocacy group known as the Fourth Avenue contingent and led by Goodwin over the last three years.

“There may be significant nibbling at the edges of these conditions that would very much affect the next five years here,” said Goodwin, who this week expressed reservations that Francis already seemed to be backing away from a commitment to install a track-operated soundproof gate at the site.

Asked about the apparent contradiction, Brunhart said Wednesday, “we did commit to a rolling gate and that’s what we’re going to do.” Francis has been on the job a year and probably was unaware of the commitment, he said.

Paving the site, another point raised by Goodwin, was under discussion, but ultimately not a required condition of the permit, Brunhart said. Gravel was deemed better for trucks, he said.

Other required conditions include working hours from 7 a.m. to 6 p.m. weekdays and weeklong closures during major holidays, Francis said. Sound walls of 10 to 12 feet around the job site are intended to contain sound to the ambient noise level of 60 decibels, as stipulated by ordinance.

The district awarded a first phase $7.1 million contract on Nov. 17 to Drill Tech Tunneling and Shoring, based in Antioch, Calif.

The district’s construction manager, Shimi Tzobery, of Parsons engineering in Pasadena, is a veteran of similar projects. He spent four years building a 3.5-mile water tunnel to Las Vegas to deepen the intake level of Lake Mead and was senior engineer for an eight-mile tunnel in Lake Arrowhead for the MWD.

The potential environmental impact in a densely populated area make the project a challenge, he said. “We have the capability to see things that should be flagged,” said Tzobery, who will rely on a crew of inspectors and each day review shift reports on activities and delays and tests of geotechnical and environmental factors.

The new project will make a few detours from the old, Brunhart said. About 700 feet of the old tunnel at its terminus in Three Arch Bay will be abandoned because of its location, which is too close to the bluff edge, he said. It will be relocated under South La Senda Drive.

Another spot near the Laguna Lido condo complex will be moved inland, out of a rock formation, he said.

The district obtained a 30-year loan at a 1.7-percent interest rate to underwrite the project, Brunhart said. Debt repayment isn’t required until the project is completed in 2022. As the district in July established water rates for the next five years, it’s too soon to know if the project will result in a future rate hike, he said.

 

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