Gas Leaks in Subway Prompt New Questions : Red Line: Quality of design, construction and supervision are under scrutiny. Officials say system is safe.

Almost daily, the alarms flash in Los Angeles’ Downtown subway, signaling that potentially explosive methane gas has seeped into the tunnels and stations.

And the rotten-egg smell of hydrogen sulfide, a toxic gas, is present in some stations, prompting complaints by subway passengers and workers.

This was not supposed to happen. To keep gases out, transit officials had spent an extra $16 million to seal the tunnels and stations in a cocoon of thick plastic. Consultants had warned that the high-tech membrane would be worthless unless it was installed and inspected with great care.

But now the incursions of the gases--and the efforts to counter them--are part of the routine in operating the city’s first subway.

When the alarms go off, workers must activate powerful fans to disperse the odorless methane before it approaches explosive levels.

The hydrogen sulfide, which can be lethal at higher concentrations, has reached levels that health experts say can cause headaches, nausea and eye irritation. Some transit police officers, concerned for their safety, have begun carrying portable gas detectors.

Metropolitan Transportation Authority officials said that although the gas concentrations need to be watched constantly, there is no danger to public safety. They said the huge emergency exhaust fans and air movement caused by trains disperse gases and keep them far below life-threatening levels.

“I think if you’ll stand at a station platform, anywhere, even in the center, you’ll feel one heck of a lot of air movement,” said Alan Dale, systems engineer for the MTA.

Experts contacted by The Times, however, said the gas leaks do raise concerns. The presence of hydrogen sulfide in particular, they said, requires further scrutiny.

The gas leaks also prompt new questions about the quality of the design, construction and supervision of Los Angeles’ $1.45-billion subway, the most expensive per mile in U.S. history.

Public records show:

* The plastic wrapping was penetrated routinely during construction--and the punctures were not always patched. According to a chief construction inspector, workers at times deliberately skirted the repair procedures.

* Elevated levels of methane have reached warning or alarm levels more than 350 times throughout the subway system during the past 15 months--far more than transit officials had anticipated.

* Hydrogen sulfide has reached the MTA’s warning or alarm levels a handful of times. Complaints from subway workers about the gas’s heavy sulfur smell also have led to activation of the fans.

* Despite the advice of safety experts, the emergency fans required to dissipate the gases can only be activated manually, rather than automatically.

* The concentrations of hydrogen sulfide may be higher than the recorded readings, experts say, because the sensors are located incorrectly. Although the gas is heavier than air, the sensors are in ducts far above the passenger platforms.

Dr. Paul N. Papanek, chief of the Los Angeles County health department’s toxics epidemiology unit, said he believes the hydrogen sulfide poses more of an odor nuisance than an imminent hazard. But Papanek expressed concern that the gas sensors are 45 to 60 feet above floor level.

“Because of the location of the probes,” Papanek wrote to the MTA two months ago, he could not “rule out the possibility of brief and localized increases in (hydrogen sulfide) concentrations in passenger areas of the subway.”

There is disagreement about the cause of the gas leaks. Design engineers have accused construction contractors of improperly installing the plastic gas barrier. The contractors say their crews complied with contract specifications--and that the work was approved by inspectors.

But records show that a chief inspector has testified privately that construction workers failed to always patch punctures in the plastic as required.

Kenneth Fossum told an MTA review board in December that the repair procedures were sometimes violated intentionally. He also said that some workers “dumped” rods of reinforcing steel directly atop the plastic.

“You had to stand with a bullwhip to get them to treat it halfway decent,” said Fossum, who oversaw subway construction for the management firm Parsons-Dillingham. A transcript of his remarks was obtained under the California Public Records Act.

The contractor whose work Fossum criticized was Tutor-Saliba Corp., which has won the most Los Angeles subway contracts. Company President Ronald N. Tutor said he was unaware of any deficient work or skirting of requirements.

If Fossum had knowledge of improper construction, Tutor said, he should have taken appropriate action. “Where the hell were they four or five years ago?” Tutor asked.

The FBI and the U.S. Department of Transportation’s inspector general are investigating the installation of the plastic membrane as part of their inquiry into construction costs on the 4.4-mile subway, according to contractors and others who have been interviewed by authorities.

*

The impetus for a gas barrier arose with explosive suddenness March 24, 1985. Methane seeping from the ground blew apart a Fairfax district clothing store, injuring at least 21 people and forcing widespread evacuations.

The blast jeopardized plans to build a subway in a city with many underground gas fields--some of them remnants of oil exploration.

Until the explosion, the Fairfax district’s congressman, Democrat Henry A. Waxman, had supported the subway. But Waxman began to question the project’s safety.

To address his concerns, the City Council appointed a committee of 10 technical experts. Their job was to assess the safety of constructing and operating the subway.

Transit engineers assured the committee that the plastic membrane, which cost $2 million per mile of tunnel, would insulate the subway from gas.

The committee concluded in 1986 that a subway could operate safely--if transit officials made certain changes, including alterations to the proposed ventilation and gas-detection systems.

The committee said gas sensors should be placed in passenger areas of subway stations, and in the elevated exhaust ducts. The committee also recommended automating the subway’s emergency fans, rather than relying solely on a human operator.

The emergency fans should be programmed to operate, the committee said, whenever gas exceeds the alarm level and operators fail to respond.

Officials of the Southern California Rapid Transit District, which then oversaw subway construction, did not place sensors inside the stations. They installed automated fans for normal cooling and ventilation, but did not automate the powerful 10-foot-tall emergency fans that have been used to disperse gases.

Dale, a part of the subway project since 1983, said there were concerns that automated emergency fans would sweep away the gas before workers could locate the source of a leak.

At Waxman’s request, Congress conditioned its funding of the subway on a rerouting around the especially gassy area of the Fairfax district, near Farmers Market.

In recent interviews, Waxman and those who served on the safety committee said they were dismayed to hear that transit officials did not follow all recommendations.

“It really is outrageous to have them disrespect the steps that should be taken to protect the public from an explosion,” Waxman said.

George W. Housner, a professor emeritus at Caltech who was chairman of the council’s review committee, said: “RTD people were (saying), ‘We’ll do everything. Whatever you need, we’ll do it.’ ”

Now that gas is leaking into the subway, Housner said, the precautions recommended by the committee are needed more than ever. “The worst the committee considered--it did happen,” he said. “They somehow punctured the (plastic) membrane.”

Another committee member, J. Davitt McAteer, now assistant secretary of the U.S. Mine Safety and Health Administration, said the gas incursions deserve examination. At a minimum, McAteer said, sensors should be installed inside the stations.

An example of what can go wrong with the present manual system occurred about 4:30 p.m. on March 30, when technicians at the MTA control room in Lynwood provided a demonstration for a Times reporter.

The emergency exhaust fans were activated but within 90 seconds, circuit breakers tripped. The fans stopped, and power went out on the Los Angeles-to-Long Beach Blue Line trolley. Rush-hour passengers massed 20 deep at the 7th and Flower streets station. One woman was trapped in an elevator. After 35 frantic minutes, regular operations were restored.

Similar glitches, including breakdowns of computerized gas-detection monitors, have occurred on a few occasions, according to records and interviews.

Everett Wooden, manager of the MTA control center, said the cause of the problem requires further investigation. The Blue Line opened in July, 1990; the Red Line subway opened in January, 1993.

The MTA’s system is designed to detect methane gas at relatively low concentrations, providing operators with sufficient time to activate the fans before the gas can rise to dangerous levels. Procedures call for activating the fans either at 5 parts per million of hydrogen sulfide--or at 15 p.p.m. of methane, far below the explosive level of 50,000 p.p.m.

The decision to track methane at such low concentrations was based on an assumption that the subway would be virtually insulated from the gas.

“We didn’t think we’d ever experience, under normal circumstances, anything higher than 20 (p.p.m.) without being darned concerned about where it came from,” said Dale of the MTA.

Records show that methane levels have exceeded 20 p.p.m. on more than 150 occasions since the subway opened Jan. 30, 1993.

But officials do not always know how high the gas levels may have risen. That is because the instruments do not record anything higher than 20 to 25 p.p.m.

“You really can’t tell: ‘Have I got 40 (p.p.m.), have I got 50 (p.p.m.)? What have I got?’ ” Dale said. “. . . Our whole theory was to be able to make early detections of methane.”

If activation of the fans fails to reduce the levels of gas, trains or stations can be removed from service. Operations have been interrupted three times, according to handwritten logs and computerized records. Each time, the fans dispersed the gas.

Although methane is odorless, hydrogen sulfide, one of the most toxic of gases, has a distinctive stench. The sulfurous odor is usually present at the Civic Center station, and sometimes at Union Station and Pershing Square.

Federal health standards warn against exposure to hydrogen sulfide at a level of 10 p.p.m. or greater for more than 10 minutes. Levels of 50 p.p.m. or more can cause serious eye injuries, and 150 p.p.m. or greater can be fatal.

The nature of the heavier-than-air gas requires careful monitoring and the placement of sensors near subway platform levels, health authorities said.

“That’s what makes the stuff so deadly underground,” said Herbert L. Venable, an industrial hygienist with the National Institute for Occupational Safety and Health. “If they don’t have monitoring in the low places, something’s wrong here. They ought to rethink it.”

Two hydrogen sulfide incursions at elevated levels were verified during a recent three-month period, according to Papanek of the county Health Department.

One was 7.7 p.p.m., within the warning level. Another, at 9.9 p.p.m., reached the alarm stage.

Three other readings, within the warning range of 5 p.p.m. to 8 p.p.m., were registered within two hours of the Northridge earthquake. Logs show that the smell of the gas prompted officials to evacuate the subway for the day.

Papanek said transit officials told him the elevated readings may have resulted from equipment malfunctions. He submitted his findings to the California Environmental Protection Agency for review.

Meanwhile, transit officials say they will raise the warning levels for methane gas when alarms are installed in the next phase of the subway, from Vermont Avenue to Hollywood Boulevard.

*

How could a subway that was specially designed to keep out gas leak so much?

Some have faulted the subway design, questioning whether the plastic wrapping could survive the less-than-gentle impacts of heavy construction.

“You have a system that is designed to leak,” said Tutor, of Sylmar-based Tutor-Saliba Corp.

Indeed, transit officials authorized Tutor-Saliba and other contractors to penetrate the plastic liner so crews could hang the plastic wrapping and pump concrete into tunnels and stations.

The contractors were authorized to shoot nails into the plastic to affix it to arches and walls. Workers penetrated the liner with metal brackets, which held in place hoses, or “slick lines” for concrete. Crews also stuck grouting pipes through the plastic liner.

Each hole was supposed to be sealed with an adhesive. The edges of the plastic wrapping were to be melted together.

The importance of proper installation was emphasized in mid-1987, before construction began, by analysts hired by the U.S. Department of Transportation.

“The adequacy of the design is based on a completely sealed lining without any openings that would allow gas or liquids to penetrate,” wrote the analysts from Hill International. “It is extremely important that the contractors and construction manager fully appreciate the significance of these requirements.”

The report, obtained under the U.S. Freedom of Information Act, warned that improper installation would defeat the purpose of spending millions of dollars for the gas and water barrier.

Yet workers sometimes failed to follow the procedures for installing the high-density polyethylene liner, or HDPE, between Union Station and Pershing Square, according to Fossum, the chief inspector.

Some workers “dumped” reinforcing steel onto the one-eighth-inch-thick plastic, Fossum said during an MTA review board hearing that was closed to the public.

Other workers who were supposed to repair accidental tears in the plastic liner sometimes did not do so, Fossum told the panel in December. “I caught them doing this on several occasions . . . which is, in my opinion, where a lot of the water leaks are coming from,” he said.

Fossum said workers whom he did not identify would “refuse to let the HDPE people make their patches.” He alleged that one of Tutor-Saliba’s superintendents, James Veatch, contributed to the problem.

“If we didn’t have a man standing in attention watching him constantly, (he) would refuse to let HDPE welders patch where the slick line brackets were removed,” Fossum said.

Records show that when Tutor-Saliba hired Veatch in 1989, he left his job as an inspector for Parsons-Dillingham, the company supervising construction.

A few months later, Veatch left Tutor-Saliba and returned to Parsons-Dillingham, where he remains a subway inspector.

Tutor said he was unaware of Veatch’s alleged conduct. Veatch disputed Fossum’s recollection. “Personally, it doesn’t sound true at all. Not even close,” Veatch said in an interview. He declined to further discuss his work on the subway.

Fossum and Veatch appeared separately before the review panel, formed in response to a Times article last year reporting numerous instances of thin concrete. The panel did not question Veatch about Fossum’s allegations.

The panel concluded that the tunnels are safe but recommended repairs, including the filling of extensive voids in the concrete.

The board noted that the plastic barrier was integral to the subway design. It said that transit officials had downgraded the quality of concrete “based on the assumption that the HDPE membrane would provide a continuous seal.”

A former Parsons-Dillingham inspector, Ben H. Pate, has said that on “several” occasions he “refused to approve shoddy and improper” installation of the plastic liner at Union Station. In a 1992 lawsuit, he alleged that he was wrongfully terminated, in part because of his refusals.

Parsons-Dillingham and the builders, Tutor-Saliba-Perini, have denied Pate’s allegations and are contesting his lawsuit in Pasadena Superior Court.

A consulting firm hired by the MTA concluded this year that Parsons-Dillingham fell short of “acceptable industry practice” in its inspections of subway work.

Documents show that warnings regarding the plastic liner were raised during construction. In a March 9, 1989, memo to his boss, Parsons-Dillingham inspector Rey Frias noted that a private testing lab, Smith-Emery Co., found widespread deficiencies.

“It is apparent,” Frias wrote, “that a drastic change in how HDPE is welded and tested by the contractor and inspected . . . is absolutely necessary or it will not be possible to sign off and document . . . that HDPE was properly installed.”

Others who have worked on the subway project believe that the plastic-lining design is flawed.

Byron Ishkanian, a geologist who oversaw construction of the first subway segment on behalf of the state labor department’s occupational safety unit, said that incursions of gas and water are understandable.

“I don’t think you could mount all the HDPE we mount without having some perforations in it,” Ishkanian told the review panel in January. “I didn’t like that shooting those nails through the HDPE because then you’re (at) the mercy of whoever puts the seal over each nailhead.”

Ishkanian also noted that water leaks are particularly troubling.

“Hydrogen sulfide and also methane do travel with water. . . . It’s a problem,” he said.

Times researcher Tracy Thomas and data analyst Sandra Poindexter contributed to this article.

Protecting the Subway

Because of concerns about the presence of explosive and toxic underground gases, the Los Angeles subway was built with a novel design. The stations and the tunnels--tops, bottoms and sides--are cocooned in a layer of plastic that was designed to keep the subway virtually free of gas. Here is how the tunnels were designed:

1) The plastic is unrolled from 600-pound spools and nailed against the supports of the tunnels.

2) Each nail hole is sealed. The edges, or seams, of the plastic are melted and sealed together.

3) The seams and the repairs to any punctures or tears are tested mechanically.

4) Once the plastic is installed and approved by inspectors, rods of reinforcing steel are placed over the material.

5) Concrete is poured over the rebar to form the finished station or tunnel wall.