Physically, it's not that hard to dig a tunnel. The hard work's taken care of by tunnel boring machines, huge metal monsters that gradually chew through the underworld like hungry worms.
Politically, things get a little more difficult.
In Los Angeles, where the politics at play include affluent NIMBYs, historic buildings and exasperated concerns about explosive underground chemicals, digging a nine-mile subway tunnel has proven to be just about as difficult as journeying to the center of the earth.
Transportation officials have long had their sights set on building a $5.6 billion extension of the city's steadily expanding subway system with a line leading out into West Los Angeles, a project currently expected to complete in 2036. The persistent kink in those plans has been the city of Beverly Hills, where local opposition to the subway's proposed route has led to a long line of public hearings, geological studies, and lawsuits to prevent those tunnel boring machines from eating their way under the city. A recently approved alignment would have the future subway running directly underneath Beverly Hills High School, a plan the Beverly Hills City Council unanimously opposes.
The Los Angeles County Metropolitan Transportation Authority, Metro, says it's the only way to go, which has set off a back-and-forth of studies from consultants on both sides seeking to prove that tunneling here is either totally safe or a ticking time bomb that could blow the school and its students into smithereens.
"My commitment has been from day one that Metro should make its decision based on science and facts, not based on hysteria and emotion," L.A. County Supervisor and Metro board member Zev Yaroslavsky told the Los Angeles Times in April.
Hysteria and emotion, though, are effective tools. In late April, the Parent-Teacher Association Council for the Beverly Hills Unified School District released this video opposing the tunneling plans. With narration like a Hollywood horror movie trailer, the video claims that tunneling under the school is unsafe because of chemical deposits and unmapped oil fields in the area that are "on the verge of exploding at Beverly Hills High, turning the school into a mega-disaster." Fireball graphics ensue.
More than 1,400 signatures have been added to a petition linked in the video calling for Metro to ditch its plans to tunnel under Beverly Hills High.
"The risks are so real that in the state of California there are no transit tunnels under any permanent school buildings," the video's narrator says. "All these dangers can be avoided if Metro sticks to its original plan to run the subway down Santa Monica Boulevard."
But that original plan was trashcanned because it's actually been found to be unsafe. In addition to hysteria and emotion, it turns out there is actually plenty of science going on here. An October 2011 report [PDF] on the fault lines in the area of the subway station alternatives found that the proposed alignment under Santa Monica Boulevard would run directly into an active fault – an observable discontinuity in the sediment of the earth that is the result of recent earthquakes and the likely site of earthquakes in the near future. In other words, it's not a great place to build a subway station where trains full of people will be parked for minutes at a time.
The alternative location at Constellation Boulevard a few blocks away that's now preferred by Metro would dig though much more stable ground. The area is technically "seismically active," meaning it's prone to experiencing earthquakes but not lying on a fault between two moving plates. In earthquake-prone California, land that's not seismically active is hard to find.
Even so, the relative instability of the ground isn't actually much of a concern, according to geotechnical engineer Ramin Golesorkhi, a vice president and director of earthquake engineering at the consulting firm Treadwell and Rollo.
"That doesn’t mean that you should not build in seismically active regions. As a matter of fact, we do that all the time. That's why we have 30 million people living in the state of California," says Golesorkhi. In fact, he argues, a tunnel through a seismically active area might be the safest thing you could build there. "Structures that are within the earth usually perform a lot better than structures that are on top of the ground, like buildings and high rises."
Even buildings like Beverly Hills High School.
Another report [PDF], released last October, found that tunneling in the area beneath the school to get to the Constellation Boulevard site would pose no significant risks, citing the safe completion of more than 30 miles of tunneling in the L.A. area recently – including seismically active areas and areas with known chemical deposits.
In late April, the Metro board certified the environmental review documents for the entire project, but because of a request from Beverly Hills for another public hearing the board stopped short of finalizing the entire route of the project. In mid-May, before an audience of more than a hundred citizens, Beverly Hills formally presented its own data on the geology beneath the school and had five experts to present the findings of various data collection efforts.
Most of the hearing was dedicated to questioning the validity of the work done by Metro's consultants, Parsons Brinckerhoff. Tunneling opponents argued that one of the techniques used to determine the geology of the earth beneath the school, a process known as cone penetrometer testing, produced unreliable results because it relies on electronic imaging rather than actual digging in the ground. "Your signature comes from a little 3- or 4-inch hole here that's pushed through the asphalt resulting in an electronic fingerprint of the holes," said geologist Eldon Gath, president of Earth Consultants International and one of the experts called in by Beverly Hills to testify. "It is an excellent tool, but it is not the only tool that you would base a decision like this upon."
He and the other witnesses argued that this led to some inconsistencies in the reporting of the location of strands of the Newport-Inglewood Fault system beneath the school. The implication is that these inconsistencies should call into question Metro's previous reports that ruled out the Santa Monica Boulevard site for being too close to an active fault.
"Just about everybody thinks that the Newport-Inglewood fault is an active fault," says Lucile Jones, a seismologist with the U.S. Geological Survey. "Whether or not the strand that runs through the high school is active, that’s what this debate is about. But that's irrelevant to the MTA's question" about the existence of an active fault at the Santa Monica Boulevard site.
Jones served as an unpaid member on an independent review panel looking at the reports produced by Metro's consultants on both the ideal location of the subway station and the safety of drilling. She and her co-panelists found that their recommendations were appropriate, and that Metro could safely tunnel under Beverly Hills High and that the new station could be safely built at the Constellation Boulevard site.
But was there any ambiguity about that science, as Beverly Hills' consultants are suggesting?
"No," Jones says simply.
Beverly Hills City Attorney Laurence Wiener did not respond to requests for an interview. Metro officials declined to comment for this article.
At the end of May, the Metro board approved the alignment under Beverly Hills High by a vote of 7 to 2. Beverly Hills Unified School District promptly filed a lawsuit claiming that Metro violated the California Environmental Quality Act in choosing that alignment.
The evidence seems to suggest that Metro's chosen location can be built safely, and that tunneling underneath Beverly Hills High won't cause a kid-killing explosion. The school district is hoping that its lawsuit will raise enough questions about that evidence to call for more study. Jones doesn't think it's needed. It will be up to the Superior Court in Los Angeles County to determine whether Metro's studies are indeed correct or if Beverly Hills has a point about the reliability of the findings. At the very least, the lawsuit has added another delay to the process of bringing a subway through Beverly Hills to West L.A. In the end, that may be the whole point.
Image credit: YouTube/Norman Orange