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Frequently Asked Questions About Belmont

What is dangerous about the Belmont site?
What is methane (CH4 )?
Why is methane dangerous?
How much methane is there at the Belmont site and where?
What is hydrogen sulfide (H2S)?
Why is hydrogen sulfide dangerous?
How much hydrogen sulfide is at the Belmont site and where?
How great a danger is hydrogen sulfide at the Belmont site?
Is methane an issue only at the Belmont site?
What makes the Belmont site different from other former oil fields that have been built on?
Why can’t the Belmont site just be cleaned up?
In brief, what are the upsides of trying to make the Belmont site work?
In brief, what are the downsides of trying to make the Belmont site work?

What is dangerous about the Belmont site?

Much of the Belmont Learning Complex site rests atop a shallow oil formation, the Los Angeles City Oil Field (see map), which stretches across a swath of Los Angeles from east of downtown to past Vermont Avenue. The underground oil deposits are a constant source of methane and hydrogen sulfide.

The greatest concentrations of these oil-field gases are in the northeastern section, near the intersection of Temple and Boylston streets, where the most oil drilling historically occurred. Construction also uncovered oil-stained soil in the site’s northwestern corner, when a hill was graded down. Methane gas is present along First Street, suggesting that hazards associated with oil fields affect the entire site.

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What is methane (CH4 )?

Methane is a colorless, odorless hydrocarbon, the lighter-than-air "natural gas" that heats your water and lights your stove — and blew up a Los Angeles department store in 1985.

Methane forms underground two different ways: either deep underground under immense pressure, or as a byproduct released when subsurface bacteria chomp on decomposing biomass — which can include oil residue.

This first method of methane production — pressure deep below the surface — is the same process that creates crude oil. Oil drilling can allow methane to migrate up to the surface.

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Why is methane dangerous?

Methane is flammable and explosive. When the amount of methane reaches 5 to 15 percent of the air in an enclosed space, any spark from electrical equipment, a match or a cigarette can literally set the air on fire. Methane isn’t known to be carcinogenic or otherwise toxic. Pure methane is odorless; the gas company adds a smelling agent, mercaptan, as a safety precaution.

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How much methane is there at the Belmont site and where?

Comprehensive soil-vapor testing of all 35 acres at once was not attempted until March 1999. Although that report calls for additional testing, the 1999 figures remain the most current. The numbers represent snapshots of gas levels that fluctuate naturally.

Every soil probe recorded methane; concentrations approaching or surpassing explosive levels were measured in 12 of 57 soil-vapor probes. Of the 12, two found methane concentrations up to 16 times above the explosive threshold five feet below ground level in the baseball field. Similar readings up to 18 times the limit also were recorded in that area from five probes thrust to depths between 40 and 78 feet below ground, mostly along the Boylston Street edge, where the heaviest oil drilling occurred. In the football field, a soil probe (27 feet underground) near midfield measured eight times the explosive level (see map).

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What is hydrogen sulfide (H2S)?

A noxious rotten-egg odor is the signature of this toxic, combustible, heavier-than-air gas, which is formed either at great depth under pressure or by sulfur-eating bacteria. Methane and hydrogen sulfide are often found together in oil fields.

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Why is hydrogen sulfide dangerous?

The consequences of breathing hydrogen sulfide include headaches, eye irritation, pulmonary damage and, in concentrations heavy enough, neural damage or death. The permissible exposure limit of hydrogen sulfide under state law is .03 parts per million per hour, although workplace standards allow exposure up to 50 parts per million for short periods of time. Prolonged exposure to 50 ppm can cause upper respiratory tract damage; exposure up to 150 ppm temporarily paralyzes the sense of smell after only a few minutes, while a few lungfuls of 500 ppm can cause unconsciousness. Minute exposure to 1,000 ppm can cause coma, neural damage and death. The cumulative effects over time of small doses are unknown and the subject of much debate. It’s almost certain that children are at greater risk of harm than adults.

 

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How much hydrogen sulfide is at the Belmont site and where?

Tests in April 1999 twice found levels up to 3,300 parts per million of hydrogen sulfide around 30 feet underground in the baseball outfield and 6 parts per million five feet down. Otherwise, one probe found barely detectable levels underneath the Administrative Center, and nothing elsewhere. March 1998 testing found around 33 ppm of hydrogen sulfide under the Administrative Center and 192 ppm under the planned Community Center. (see map)

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How great a danger is hydrogen sulfide at the Belmont site?

Some experts minimize the need for special protection against hydrogen sulfide at Belmont. Widespread hydrogen sulfide was not found, and they downplay the possibility that this heavier-than-air gas would migrate to the surface in a damaging quantity.

Others take the potential risk seriously, given that hydrogen sulfide can be carried upward by other gases, such as methane. And there are plenty of anecdotal accounts, going back years, of neighborhood residents reporting the distinctive rotten-egg odor of hydrogen sulfide. Somehow, some hydrogen sulfide is making it to ground level.

In regards to inside areas, any barrier and venting system that would protect the school’s buildings from methane also would keep out hydrogen sulfide.

On the playing fields, the key to dealing with hydrogen sulfide is to prevent exposure to a harmful dose that would somehow reach ground level. It’s possible that this would never happen in the first place. "The scenario is somebody’s lying down by the grass and you might get a release of gas from a fracture close to the surface," explained L.A. Unified safety director Angelo Bellomo. Safety experts have a fix in mind, just in case. One suggestion is to bury a permeable layer of sand or gravel that would impede gases from migrating easily upward, while also dispersing them naturally throughout this layer. Thus, no significant dose would reach ground level. In case of a pressure buildup, this system could incorporate a backup plan: collection pipes leading to a tank.

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Is methane an issue only at the Belmont site?

No. Even though a portion of the Belmont site overlaps the L.A. City Oil Field, so do a lot of other properties, including some currently operating schools. The eastern portion of the oil field begins just south of Dodger Stadium along both sides of the 110 freeway, including Chinatown. The field then cuts across the northern edge of downtown (crossing a portion of the Belmont Complex site), then heads west, ending just past Vermont Avenue. (see map)

If the presence of methane were a disqualification for construction, much of Los Angeles would have to be abandoned. Methane emanates from abandoned wells, active oil fields and natural seeps across the basin from Beverly Hills to Newport Beach to the Puente Hills.

Los Angeles’ Fairfax District, in particular, built atop the Salt Lake Oil Field and home of La Brea Tar Pits, is chock-a-block with methane. L.A. City Code designates a 3-square-mile area roughly bounded by Olympic Boulevard on the south, Rossmore Avenue on the east, Oakwood Avenue on the north and San Vicente Boulevard on the west as a "Potential Methane Zone." Part of that area (see map), including the apartment buildings of Park Labrea, Farmers Market and museum row, is classified as a "High Potential Methane Zone."

A methane explosion in a Ross Dress For Less store near Third Street and Fairfax Avenue in 1985 injured two dozen, including a woman who received burns over 50 percent of her body. The incident led to city regulations governing how methane should be dealt with at existing buildings and at new construction. Hancock Park Elementary School is inside the High Potential Methane Zone. Ironically, the Belmont Learning Complex is not in any methane zone whatsoever, which merely proves that the city’s official view of where methane exists needs updating.

Construction for the celebrated new wing of the Central Library, well outside the official methane zone, had to be temporarily halted due to the discovery of methane. And the presence of methane led to the installation of plastic methane barriers along the entire 17.4-mile Red Line subway system that begins downtown, travels through Hollywood and ends in the San Fernando Valley.

Outside L.A., Hoag Hospital in Newport Beach is also built on methane-saturated ground. A state-of-the-art system there utilizes the methane as energy for the heating and cooling system, while also scrubbing the gas free of toxic hydrogen sulfide.

Other LAUSD schools with methane problems include Towne Avenue Elementary, Park Avenue Elementary, and Francis Polytechnic High, schools that were built close to landfills, which also generate methane. Park Avenue School actually sits on top of a landfill that contains toxins. Potential safety hazards at these schools go beyond methane to include landfill-related toxins, some of which are carcinogenic.

 

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What makes the Belmont site different from other former oil fields that have been built on?

The L.A. City Oil Field is unusually shallow, between 350 and 1,700 feet deep, and compared to other Southern California oil fields, contains higher concentrations of hydrogen sulfide.

A full study of the site’s geology was never completed, and project critic Bernard Endres (See "The Experts") contends the site is a unique "outcropping" of oil transported from deep underground by a blind thrust fault. But Belmont is not uniquely shallow — the neighboring Salt Lake Oil Field (in the Fairfax District) has a similarly shallow depth. As long as a good safety system is installed, the exact nature of the Belmont oil field is not likely to be relevant, according to district officials and experts in the field, with the exception of Endres. Available evidence suggests, in fact, that the Belmont property is not fundamentally different from the sites of other Los Angeles building projects, including the Central Library expansion, where construction also began without an end-to-end study fully assessing environmental hazards. Nor are levels of gas at Belmont higher than at other brownfields that have been successfully built on, such as Hoag Hospital.

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Why can’t the Belmont site just be cleaned up?

A cleanup might be possible if these gases were from chemical spills or from leaking underground tanks left from the upholsterer, body shop and gas station that used to operate at the Belmont site. But the main source of methane is the oil field itself. Old oil-well shafts, in particular, offer paths for methane to rise to the surface. How many old shafts there are on-site hasn’t been determined with certainty, although 11 wells were found and re-plugged to modern safety standards. And another, active well was plugged because it had the misfortune of being near second base. (In its place – and off the field – the district drilled a pressure-monitoring well that could be used to extract oil if necessary.) Because wildcatters and oil companies descended on this oil field before state regulations mandated careful record keeping, it’s impossible to say how many boreholes were drilled. (See "Then and Now" and map)

Nor is the path that methane takes constant. Earthquakes, for example, create new cracks in the ground, through which methane can travel upward. Any part of the Belmont site is a potential vent for gas.

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In brief, what are the upsides of trying to make the Belmont site work?

The source of gas can never be removed from Belmont, but an active ventilation-and-barrier system underneath the buildings can reduce the risk to near zero. Methane is only dangerous if it accumulates inside a building; in open air methane can never reach 5 percent of the total air volume. A system of underground tubes that vent above roof level can suck up accumulating gases and expel them safely. One method for dealing with hydrogen sulfide is to separate it from the methane and pipe it into collection tanks. But it isn’t clear, based on the testing, that any hydrogen sulfide would ever migrate into the buildings in the first place. The mechanics of a safety system, based on existing technology already employed elsewhere, are less complicated than many other aspects of a construction project this size.

Methane poses no danger in the open air of the athletic fields, although potent underground concentrations of hydrogen sulfide have been measured 30 feet below the surface level of the baseball field. A layer of porous material, such as sand, would slow gas migration from below, diluting the surface concentration of hydrogen sulfide concentration to near zero.

Completing Belmont safely would relieve intense school overcrowding in that area and salvage a $200 million project. Paradoxically, opening the Belmont Learning Complex might even decrease students’ exposure to toxins, reducing, for example, the necessity of long commutes in buses that leak carcinogenic diesel fumes. The cancer risk at Belmont comes from above, not below — from breathing the air. The school is adjacent to the Harbor Freeway, and all the car exhaust it generates. On the other hand, replacement sites suggested for Belmont also are next to this freeway or other freeways.

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In brief, what are the downsides of trying to make the Belmont site work?

 

Immediately after the 1985 Ross explosion, a vent well was drilled so that methane could escape harmlessly into the air before accumulating to a dangerous level. Only four years later, the well was clogged with silt, and explosive levels of methane accumulated in a basement next door. The dangerous conditions were discovered and corrected before an explosion occurred, but the episode underscores that a mitigation system is only as good as its upkeep.

And the school district has a poor record on environmental matters; an "interim" safety system at Park Avenue Elementary was allowed to remain in place for more than a decade, violating a Cal-EPA directive. A toxic-soil cleaning system at Jefferson New Middle School discharged potentially dangerous fumes into areas filled with students. Another vapor-extraction system at Gratts Elementary wasn’t properly monitored. As a result, it was out of service for almost a year. Likewise, methane monitoring systems in Towne Avenue Elementary and Francis Polytechnic weren’t maintained for years. And ominously, it took a pressure from the Fire Department and the Division of Oil and Gas before the school district got around to capping a pressure-monitoring well at Belmont. This oversight never put anyone in danger, but it raised questions all over again about the district’s vigilance.

Engineers are confident that they can design an effective safety system. But can anyone put faith in LAUSD’s promises to maintain it?

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