The Methane Down Below

[Guest guest]

Friday, July 30, 1999

The Methane Down Below

Problems with the Belmont Learning Complex are the latest in a region dotted

with abandoned oil wells that can leak the explosive gas. Building codes

have been developed to minimize risks.

By EDWARD J. BOYER, JANET WILSON, Times Staff Writers

One witness thought it was " raining fire. " The earth was belching flames

through cracks in the pavement, tongues of fire marching in a steady

progression across a shopping center parking lot on 3rd Street near Fairfax

Avenue in West Los Angeles.

The methane gas explosion that ripped through a Ross Dress for Less store in

March 1985 left 24 people injured and forced the closure of stores in the

center for several days.

Nature had sent Los Angeles yet another potentially lethal message: Without

adequate venting, methane trapped below pavement can build to explosive

levels with disastrous results.

Echoes of that explosion have been very much on the mind of Angelenos as the

Los Angeles Unified School District board wrestles with ways to solve the

problem of methane seeping through the earth at its half-completed Belmont

Learning Complex site just west of downtown.

If the methane problem at Belmont cannot be solved, the school district may

be forced to abandon the $200-million education and retail project.

Safety Questions

The controversy swirling around Belmont has raised questions regarding the

safety of residential and commercial developments in other parts of Southern

California.

The region is dotted with working and abandoned oil wells from Santa Clarita

in the north to Newport Beach in the south. And where there are oil wells,

there is methane.

Does that mean neighborhoods and commercial developments built on old oil

fields face the same risks that have caused so much concern at Belmont?

There is certainly risk whenever explosive gases are present, experts say,

but building codes and state agencies have been able to keep that risk at

manageable levels for the most part.

When builders follow proper procedures to vent methane, the risk of

accidental explosions is virtually eliminated, experts say.

Having pumping oil wells on a site is better than having improperly

abandoned wells because working wells vent methane harmlessly into the air,

said Baker, district deputy of the state Division of Oil, Gas and

Geothermal Resources.

Huntington Beach-based petroleum drilling consultant Dick Chalk stressed

that " the potential risk of methane problems is probably very small, but

it's always a possibility. It's that 1% chance that worries you. The gas

will seep up through cement, and eventually come to the surface. It's just

good oil field practice to go ahead and vent something. Otherwise, an

explosion can happen. "

Colorless, Odorless --and Explosive

Methane is a colorless, odorless, highly explosive byproduct of the oil

fields on top of which much of the metropolitan region is built. The 70-odd

fields in the region are primarily clustered along the area's major

earthquake fault lines, where oil seeps out of the ruptured rock.

Over several decades, as Los Angeles and its environs have shifted from an

oilman's town to a developer's dream, three-quarters of the area's 33,000

oil wells have been abandoned.

" The only open space left to build on in L.A. is the open oil fields, so

people are building there, " said Baker, who oversees review of all

construction permits for Los Angeles and Orange counties to make sure old

wells are properly capped and vented.

" Land values are so high, by building houses you can now make more money

than pumping oil, so there's a big urbanization pressure, " he said.

And that means underground pressure in oil fields begins to build back up.

Once a well is abandoned or sitting idle, " what Mother Nature did to create

the oil field, Mother Nature is going to continue to do--fill that oil field

back up, " Baker said.

That repressurizing may cause oil to seep, and with the seeping oil come

swelling methane fumes. If those fumes find a weak link in an old well,

where they can mix with air, they can and do explode, ignited by as little

as a light switch being flicked on. Methane in concentrations as low as 5%

can be explosive.

" If you have oxygen and gas and a spark, you get an explosion, " Baker said.

It is impossible to know how fast an area of an oil field will repressurize,

but there are telling examples.

In 1973, a retired sea captain's Newport Beach cottage began filling up

rapidly with crude oil. The culprit was an abandoned oil well directly

below. The force of oil rising from the improperly sealed well cracked the

concrete foundation and flooded the kitchen.

" Mostly the old wells just belch out oil and gas, " Baker said.

The captain's house was partially torn down to get to the leaking well,

which was then properly capped.

Several years later, a real estate agent preparing to show a house in

Newport Beach turned on a light switch, and the house burst into flames and

was gutted. No one was killed. The fire was attributed to trapped methane

from an old well.

Four years after the Ross Dress for Less explosion in the Fairfax

district--just blocks from the sprawling Park Labrea apartments--methane

appeared in nearly explosive concentrations in the basement of a Kmart store

in the same area.

The 1985 shopping center explosion led to quick passage of state legislation

that set aside funding for testing and remediation. Numerous old wells have

been properly shut down as a result, but others, especially wells from the

last century that were abandoned before the state oil and gas division was

established, are uncharted territory.

After the Ross explosion, wells were sunk near the shopping center to

relieve pressure and gas detectors were installed, said Dana Prevost, an

engineering geologist in the city Department of Building and Safety.

Los Angeles also revised its building code, in some cases requiring vents

and nonporous membranes beneath a building's slab to direct methane to

vents, he said.

Sepich, a methane specialist who runs Sepich Associates in Moorpark,

said that even high concentrations of methane in the soil are not a problem

if construction firms follow the Los Angeles Building Code, which he said

embodies an " extremely conservative " approach to the explosive gas.

The code calls for laying down perforated pipes to collect and vent the gas,

and then covering the pipes with a plastic membrane.

The membrane, he said, is essentially stretched " like a drumhead " between

foundation footings. Then the foundation slab is poured on top.

The code calls for methane detectors or fans to be installed in the building

aboveground, he said.

Sepich said he recommends installing the membrane underneath foundations

where methane is found in excess of 1.25% of air by volume.

Just such a membrane is being placed on a building under construction less

than three blocks from the Belmont site because an area along one side of

the foundation was found to be contaminated with methane.

Barriers for Buildings

Sepich's firm was hired to design a methane protection system at Belmont.

His design, which was being implemented before work on the system was

suspended, included a barrier under buildings and passive collection through

perforated plastic pipes.

He has designed barriers for other buildings, including the Los Angeles

Central Library. He said his firm designed the methane barrier for the

library after testing found areas where the methane concentrations were much

greater than at Belmont. And he said they were discovered in much the same

way--after construction had started and the environmental testing firm

detected methane in sample borings.

" My feeling is that the gas situation at the library is much more severe

than it is at Belmont school, " he said.

The library job, however, was more involved because it required building a

membrane under a basement reaching 60 feet into the ground. In addition to

the barrier, he said, the library has methane gas detectors inside.

For all the risks that building on old oil fields poses, " accidents are few

and far between, " Baker said. " Cities and developers want to have safe

projects. "

In the Los Angeles Basin, all cities where oil operations are underway send

developers to the state Division of Oil and Gas to have their projects

reviewed, Baker said.

Although those referrals are voluntary and advisory, Baker said, " I think it

has worked pretty well. "

Keim, the principal inspector at the Los Angeles Department of

Building and Safety, said his office refers all permit applicants to the oil

and gas division if they want to build on old oil fields.

" We require clearance from oil and gas before we issue a permit, " he said.

But some governmental agencies do not need such a clearance to build. School

districts get their clearances from the office of the state architect. The

Division of Oil and Gas may review the project, but it has no power to block

it.

In Belmont's case, Los Angeles school officials' long frustration over being

unable to build a new high school near downtown led them to cut many corners

in their environmental reviews of the project.

First, to purchase the land quickly in 1994, they declared that there would

be no negative environmental impacts. At the time, however, a widely

distributed memo outlined deficiencies in the assessment of the hazards of

methane and other oil field chemicals. But those concerns were not addressed

in the district's later environmental impact report.

The omission kept the state Department of Toxic Substances Control out of

the review process when the district presented its Belmont plans to the

state architect.

Baker said he and his staff repeatedly told L.A. Unified about the oil wells

on the Belmont school site, " as far back as 1989. "

Since cities and counties require private developers to get approvals for

their projects from the state oil and gas office, the agency now reviews

1,200 applications for building permits a year--a sharp increase from the 40

or 50 it reviewed just 15 years ago.

Each developer must obtain oil maps from the state office, then excavate the

site to determine if wells are on the property and where they are.

" The first thing we always tell them is it's better not to build over a

well, " Baker said. " We recommend they don't. "

There may be a well on the property, Baker said, but his office tells

developers to design their projects so that no structure is directly over

the well.

If it is necessary to put a building over the well, Baker said, the

developer should ensure that the well is brought up to current standards

with plugs and venting.

Any leaking well on the site, even if it is not near the planned building,

must be reported immediately, and all wells under houses or businesses must

be vented.

Tests for leaks and on-site inspections of capping and venting are done by

state engineers before certification is issued.

Among the newer housing developments atop old oil fields, upscale Huntington

Place in Huntington Beach offers a good example of yet another reality of

modern-day Southern California living.

On the sidewalks in front of the million-dollar homes in the gated community

are tall, spindly concrete structures that look like lampposts without the

lamp on top.

They are methane vents.

" Yeah, we signed a disclosure report saying we'd been told that was to vent

the gas, " said Lang, who moved in with her family two months ago. " My

husband and I really weren't concerned about it. I've never noticed any

smell or anything. You could just worry yourself away about every little

thing--earthquakes, floods, oil--or you can just live in the house you want

and not worry. "

Times staff writers Ralph Frammolino, Neda Raouf and Doug contributed

to this report.

* * *

Oil and Trouble

Oil drilling is a century-old fact of Southern California life.

Doheny discovered oil in 1892 west of downtown Los Angeles, just blocks from

the Belmont Learning Complex site. Pools of black gold may harbor the risk

of potentially explosive methane that can seep to the surface, making

measures to control it important in construction codes.

Types of Methane

* Shallow biogenic methane is created as bacteria in the soil decomposes oil

discarded during drilling, leaving methane as a byproduct.

* Petrogenic methane is formed along with other gases deep within the oil

field, and rises to the surface through rock layers or old oil well shafts.

Geology

The ground beneath Los Angeles is made up mostly of sedimentary layers that

were laid down millions of years ago before the inland seas that once

covered the L.A. Basin receded. Over time, a combination of pressure,

tectonic activity and erosion brought oil-bearing layers close to the

surface.

Danger

Methane presents a risk of explosion when it accumulates in an enclosed

structure. Mixtures of methane and air with the methane content between 5%

and 15% by volume are explosive.

Remedies

1. Capping and venting abandoned wells.

2. Laying down perforated pipes to collect and vent methane, and then

covering the pipes with a plastic-type membrane that directs the gas into

them. A building's foundation slab is then poured over the membrane.

3. Installing methane detectors or fans in a building above ground.

Source: California Conservation Dept., Division of Oil, Gas and Geothermal

Resources; Los Angeles Times archives

Friday, July 30, 1999

Vulnerable to Vapors

Abandoned Oil Fields Leave Dangers of Methane Blasts

By JANET WILSON, Times Staff Writer

ADVERTISEMENT

s if earthquakes weren't enough, there's another invisible danger lurking

beneath the Los Angeles Basin, from Newport Beach north to Newhall.

It is methane--a colorless, odorless, highly explosive gas naturally

produced by the 70-odd oil fields on top of which much of the metropolitan

area is built. The fields are primarily clustered along the area's major

fault lines, where oil seeps out of ruptured rock.

So, if your community is built on or near a fault, there's a good chance

it's also sitting atop abandoned oil wells--and methane. If not properly

vented, the gas can work its way through even concrete foundations and cause

disastrous explosions.

For decades, as Los Angeles and its environs have evolved from an oilman's

Eden to developer's heaven, three-quarters of the area's 33,000 oil wells

have been abandoned, and the risk of trapped methane gas under the surface

has grown.

The latest example is the half-finished Belmont Learning Center in Los

Angeles, a $200-million high school project that has been stopped in its

tracks by belated official recognition that methane is seeping up from the

earth beneath the site. If the methane problem cannot be solved, the school

district may be forced to abandon the costly project.

Along the portion of Orange County's coast that roughly coincides with the

Newport-Inglewood fault, everyone from hospital construction teams to

developers of gated communities are taking measures to reduce the threat of

methane--or to harness it as an energy source.

The reason is simple: " The only open space left to build on . . . is the

open oil fields, so people are building there, " said Baker of the

state Division of Oil, Gas and Geothermal Resources. Baker oversees

construction permits for Orange and Los Angeles counties that make sure old

wells are properly capped and vented.

Ironically, when it comes to methane, it's better to have pumping oil wells

in residential areas than abandoned wells without proper venting. Once a

well is abandoned, or even sitting idle, " what Mother Nature did to create

the oil field, Mother Nature is going to continue to do--fill that oil field

back up, " Baker said.

And with the seeping oil come swelling methane fumes. If they find a weak

link in an old well, where air mixes with the fumes, they can and do explode

outward, ignited by as little as a light switch being flicked on.

" If you have oxygen and gas and a spark, you get an explosion, " Baker said.

It is impossible to know how fast an area of an oil field will repressurize,

but there are telling examples.

In 1973, a Newport Beach cottage owned by a retired sea captain began

filling up rapidly with crude oil.

The culprit was an abandoned oil well directly below.

The force of oil rising from the improperly sealed well cracked the concrete

foundation and flooded the kitchen.

The house was partially torn down to get to the leaking well and properly

cap it.

Several years earlier, a real estate agent preparing to show a house in

Balboa Coves sparked an explosive fire by turning on a light switch.

No one was killed, but the house was gutted in the blaze, which was

attributed to trapped methane from an old well.

The most damaging of such incidents in recent years was a March 1985 methane

explosion in a discount clothing shop in the Fairfax district of Los Angeles

that injured 24 people.

The explosion led to quick passage of legislation that set aside funding for

testing and other steps to stem the threat.

He said an estimated 140,000 cubic feet per day of gas shoots out of the

earth's crust at that particular spot.

Today, as part of a $1-million methane mitigation project, the blue flame so

familiar to longtime county residents is no more.

Instead, the fumes pouring out of the underground field are funneled through

underground pipes, and scrubbed clean of the more toxic hydrogen sulfide.

Then they are either vented through a tall chimney, or funneled into pipes

that run into hospital boilers.

Officials said the fuel will never provide all of the hospital's power, but

could help.

A thick plastic liner also was laid under the concrete foundation of a new

administration building to prevent any methane seepage.

Hoag hospital is right across the highway from the neighborhood where the

real estate agent turned on the light switch and blew up the house, and the

hospital pumps out methane from under those houses now as a community

service, according to Reveley.

No state law requires that permits be obtained to build on top of oil

fields.

But many city and county building laws require approvals from the state oil

and gas office before they will issue permits.

The office used to receive 40 or 50 applications annually 15 years ago. They

now review 1,200 per year.

Each developer must obtain oil-well maps from the state office, then

excavate the site to determine if and where the wells are on the property.

Any leaking well on the site, even if it is not near the planned building,

must be reported immediately, and all wells under houses or businesses must

be vented.

State engineers test for leaks and inspect capping and venting procedures

before issuing a certificate that the developer must present to city or

county building permit officials.

" We will always tell people, with the earthquakes, ground settling, all

kinds of dynamics going on underground, the best way to mitigate is don't

build over oil wells, " Baker said. If they must build on them, then they

need to vent, he said.

Upscale Huntington Place in Huntington Beach offers a good example. On the

sidewalks in front of the million-dollar homes in this gated community are

tall, spindly concrete structures that look like lampposts without the lamp

on top. They are methane vents.

" We signed a disclosure report saying we'd been told that was to vent the

gas, " said Lang, who moved in with her family two months ago.

" I've never noticed any smell or anything. . . . You could just worry

yourself away about every little thing--earthquakes, floods, oil--or you can

just live in the house you want and not worry. "

Times staff writer Boyer contributed to this story.

* * *

Oil and Trouble

Oil drilling is a century-old fact of Southern California life.

Doheny discovered oil in 1892 west of downtown Los Angeles, just blocks from

the Belmont Learning Complex site. Pools of black gold may harbor the risk

of potentially explosive methane that can seep to the surface, making

measures to control it important in construction codes.