Work near CTA Yellow Line raised alarm before embankment collapse

Aug. 20--Weeks before an embankment collapse shut down the CTA's Yellow Line this spring, concerns were expressed over whether nearby construction at a sewage treatment plant in Skokie was causing too much movement in the tracks, emails obtained by the Tribune show.

Monitoring of the CTA rails and a steel bridge revealed that vibrations, settlement and movement of the track system often exceeded the limits initially laid down by transit agency officials to safeguard Yellow Line commuters riding across the 50-foot-high dirt embankment, according to the internal emails and other documents.

The situation was further complicated by changes in the design of waste disinfection facilities that pushed construction at the Terrence J. O'Brien treatment plant even closer to the Yellow Line viaduct, according to the documents released by the Metropolitan Water Reclamation District of Greater Chicago in response to a Tribune public records request.

On May 17, during a daylong break from excavation work at the sprawling wastewater plant that included driving heavy pilings deep into the ground, part of the CTA embankment buckled. A CTA train that approached the breach that Sunday night stopped in time. The Yellow Line hasn't run since, and officials say it won't until October.

In the interim, Yellow Line commuters, who accounted for about 2,900 trips each weekday, have been forced to use much slower shuttle buses between Skokie and the Red Line terminal at Howard Street or find another alternative. The free buses have attracted only a few hundred riders a day, transit officials said. The shutdown not only has hurt businesses in downtown Skokie, where a station at Oakton Street opened in 2012, but also cut off the transit agency's heavy maintenance facility. Now, rail cars must be trucked in and out of the facility or sent elsewhere for repairs, officials said.

The water district still is investigating what caused the embankment to fail, though there is no question that the construction triggered the accident, officials say. How quickly and easily the embankment can be rebuilt and train service restarted isn't clear, with CTA and water district officials disagreeing on what the work entails or even when it should begin.

Safety rules altered

Several weeks before the more than 100-year-old embankment failed this spring, the water district's contractor, Walsh Construction Co. II, asked to loosen the rules governing how much the elevated railroad tracks could be allowed to move -- up, down and sideways -- during construction at the wastewater treatment plant, documents show.

By agreement, the bounce, as engineers call it, could not exceed a quarter-inch. If more movement was detected, construction operations were required to stop immediately. The CTA would then conduct inspections and decide how to proceed, documents specified.

But excessive track movement became a chronic issue when excavation for the disinfection facilities ramped up this year. In April, a month before the CTA embankment failed, survey monitoring results of the tracks some distance north of Walsh's work showed variations surpassing an inch of movement, documents show.

Matt Pozzi, Walsh's project manager, said in several emails to CTA and MWRD officials that some of the movement might have been because of temperature changes, but Pozzi recommended on April 15 that engineers from the transit agency conduct a site visit "to make sure everything is up to CTA's standards."

"The 1/4-inch tolerance will be an issue every time we take readings," Pozzi wrote in a follow-up email on the morning of April 16 to the CTA's construction oversight manager and other officials. "Is there a way we can relax this requirement, or to further define what movements constitute Walsh stopping work?"

Pozzi suggested that a tripling of the safety tolerance -- to three-quarters of an inch -- be allowed under the stipulation that the CTA would be notified.

"Movements over 3/4th inch, Walsh stops work until CTA authorizes work to proceed," Pozzi proposed in the email.

About two hours later, the CTA construction oversight manager, a contract worker named Michael McCarthy, sent Pozzi an email approving an increase in the tolerance to a half-inch. "Any movements greater than 1/2 inch will require a work stoppage," wrote McCarthy, who is employed by Chicago Transit Partners, which has offices in the CTA headquarters building downtown.

McCarthy cited "ground thawing" and a "re-baselining," or recalibrating, of survey settings as justification for the more lenient safety standard.

Then at 1:21 p.m., less than two hours later, McCarthy sent Pozzi another email: "Upon further review, CTA accepts your proposal that for movements 1/4 inch to 3/4 inch, Walsh notifies CTA and continues work and for movements over 3/4 inch, Walsh stops work until CTA authorizes work to proceed."

Walsh, which is one of the largest construction contractors in Illinois and has built numerous projects for the CTA, did not respond to Tribune questions for this article.

CTA officials told the Tribune that they were confident about relaxing the rules because in addition to the normal visual inspections conducted by CTA track crews, Walsh had been using special monitoring equipment while digging was going on near the Yellow Line.

Up to two inches of track movement has been allowed in some CTA projects, said Jim Harper, CTA chief engineer of infrastructure. But such a change usually requires additional precautions, typically including extra track maintenance checks and safety measures such as reducing train speeds, he said.

Two independent engineers who are familiar with CTA operations said it is accepted practice to conservatively set a limiting metric for track movement based on information in hand, and then to modestly increase the limit, if necessary, to a predetermined maximum as a project proceeds and while continuing to monitor conditions below surface level.

As construction at the O'Brien wastewater treatment plant progressed last spring, excessive movement of the CTA tracks and the sloped embankment prompted construction stoppages at least two times, said Allison Fore, a MWRD spokeswoman.

More issues pile up

In late 2014, an engineer reviewing blueprints to build the $60 million waste disinfection facilities project discovered that existing pipes buried 50 feet under the treatment plant, which dates to 1928, would not line up to connect with new pipes that were to be installed near the CTA embankment. The solution to the misalignment was to extend the construction zone eight feet closer to the embankment, according to a contract change order that was approved by the water district board in March.

The work covered in the change order required "additional excavation and reinforcement," according to the district. The digging and shoring up were being done on the weekend of the embankment collapse, documents show.

This design modification was worrisome to CTA officials.

"The eight-foot change brought the construction work much closer to our track. It was a concern," Harper said in an interview last week. As a result, Walsh was required to make changes in the installation of pipes for the disinfection facilities, including doing some of the work during overnight hours when the Yellow Line was not running, he said.

How to rebuild

With just about two months before the promised reopening of the Yellow Line, decisions about how to rebuild the embankment are on hold, CTA officials said. The fix must be based on the outcome of the water district's ongoing investigation into what caused the embankment to fail, transit officials said, emphasizing that their top priority is to prevent any possibility of a recurrence, followed next by resuming rail service as soon as possible.

"Once the cause is determined, there has to be an engineering solution," said Dave Kowalski, CTA senior adviser on safety initiatives.

But the top official at the water district said the process can be expedited so that the Yellow Line reopens in October, as previously promised. Besides, it might take a year to get to the bottom of why the embankment gave way, said David St. Pierre, MWRD executive director.

"The bank restoration and track replacement are pretty straightforward and simple. You don't really need to know what caused the failure to rebuild the embankment," St. Pierre told the Tribune this week.

After the collapse, water district and CTA officials said they agreed that the most efficient and safest solution was to first complete the sanitation pipe construction, then worry about rebuilding the embankment once the cause of the collapse was known. Under an agreement between the agencies, the pipe work is scheduled to be completed in early October, St. Pierre said. In order to meet the end of October deadline, the CTA will have just a few weeks to rebuild the track, install signals and run test trains, officials said.

The emails obtained by the Tribune reveal what appears to be a lack of urgency by the public agencies and Walsh. A full month after the collapse, officials were discussing when to hold "coordination meetings" on how to begin cleaning up the embankment landslide. The MWRD said 19 emails related to the embankment collapse were exempt from disclosure to the Tribune under the Freedom of Information Act.

CTA, riders both lose

The CTA is tallying losses related to the Yellow Line shutdown and the accident investigation. The cost through the end of June is $2 million to $3 million, according to provisional CTA calculations.

The revenue drop-off includes a range of categories, from lost fares and free shuttle bus service, to uncollected parking fees at the Dempster Park-n-Ride lot (which now offers free parking as a service to shuttle bus commuters) and costs related to the Skokie Shops rail repair facility being inaccessible by track. The transit agency plans to send the final bill to the MWRD, the CTA's new president said.

No lawsuits have been filed to date, but some experts said litigation is inevitable. St. Pierre said insurance will protect the water district and taxpayers.

The district has not publicly disclosed the cost of the accident.

"We don't believe it will be the district's (insurance policy) deductible," St. Pierre said. "It will be someone else's deductible, whether Walsh or someone else."

Retired college professor William Graddy said he and his wife moved to Skokie 28 years ago in part because of the CTA rail service, then called the Skokie Swift. "If an October date for renewed operation is still possible, then repair must be underway, but I'm guessing that the only work sites currently active are law offices."

Graddy, 71, said he is concerned that Yellow Line riders will abandon the service and that the CTA might respond by doing something drastic, like eliminating weekend service.

Asked whether Yellow Line customers should count on service resuming in October, CTA President Dorval Carter Jr. said: "I have a confidence level they are doing everything they can. But these projects, they get done when they get done."

The CTA examined whether it would be possible to temporarily repair the embankment and tracks to restore Yellow Line service while permanent fixes were made, and agency officials decided that "none of the concepts offered more than a marginal time savings," said CTA spokesman Brian Steele.

But the projected five-month shutdown of the Yellow Line seems excessive to some transportation experts, who said there is no technological reason that a temporary bridge could not be built to run trains while a permanent fix is designed and built.

"Could they do a temporary restoration (of the embankment)? It is hard for me to imagine that they couldn't. They replaced much longer bridges in Evanston in 60 hours," said Joseph Schofer, associate dean of the McCormick School of Engineering at Northwestern University.

Schofer said the monthslong service interruption will make it difficult for the CTA to win back the 2,600 rider trips that the Yellow Line provided on an average weekday.

"Nobody wants to beat up on CTA," Schofer said. "But someone goofed, and the slow restoration compounds the error."

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