Gale Swan has lived for 62 years by the eastern slope of the hills below where La Cienega Boulevard and La Brea Avenue crest a few miles south of the Santa Monica Freeway. The upscale homes that spider down these curving streets offer enticing views of the Los Angeles Basin.
Yet, Swan is worried.
She has been through L.A.'s heavy winter rains and the 1963 collapse a few neighborhoods away of the Baldwin Hills Dam.
But now the foundation of her 1946 house in View Park has cracks. Although it's true these hills sit on the Newport-Inglewood fault, Swan is circumspect.
"I've lived through all kinds of earthquakes, and suddenly they're appearing," she said of the cracks.
Farther west, Cheryl Slesthenter and Vivian Harris stand in their Baldwin Hills kitchen where the cabinets are splitting from the ceiling. They have lived here since 1974. In the last few years, hairline cracks have randomly appeared on their walls.
"It's gotten worse over the last year," Harris said. "I'm afraid the walls are going to break open."
No one who lives here doubts that the land is shifting. There are cracked swimming pools, broken driveways, uneven garage doors and displaced sidewalks.
The problem is, no one knows why.
"We've always suspected it was them," Harris said, eyeing their neighbor to the west — the Inglewood Oil Field.
Now operated by Plains Exploration & Production Co., or PXP, the nation's largest urban oil field is at the center of a study that may provide some answers for residents.
The study is on fracking — an efficient but controversial method of extracting oil and natural gas from areas once thought to be depleted — and results should be in hand by next month.
Steve Rusch, vice president of the Texas-based company, said the study is the first of its kind in California.
He acknowledges having received about a dozen claims from residents who allege damage to their homes was caused, at least in part, by PXP's drilling operations.
"We've made contact with those folks," Rusch said, adding that the process of addressing the complaints is ongoing. "We know we have to be a responsible operator."
That didn't stop more than 400 people from gathering at Culver City Hall this month to push for a ban on fracking in California.
Fracking, shorthand for hydraulic fracturing, involves drilling a hole in the earth, then blasting millions of gallons of water infused with sand and chemicals to shatter rock formations deep underground to release natural gas and oil trapped in the shale.
The method has come under criticism. Late last year, the Environmental Protection Agency issued a report in a Wyoming case in which federal regulators said fracking was the probable cause of tainted water supplies. Then in March, scientists from the U.S. Geological Survey said fracking may be behind an increase in seismic activity near extraction sites.
L.A. County Supervisor Mark Ridley-Thomas, whose district includes the oil field, said residents have contacted his office about property damage, but he wants to see the results of the study before drawing any conclusions.
"I'm very concerned," he said. "People have a right to know whether their property has suffered because of the natural shifts related to the active fault line there or manmade activities."
The Newport-Inglewood fault, which seismologists say is capable of producing a magnitude 7.4 quake, begins off the Orange County coast and extends 50 miles northwest through Long Beach, Inglewood and into West Los Angeles. The 1933 Long Beach quake erupted along this seismic rift.
Scientists, however, say any land shift cannot be easily narrowed to a single cause because of the area's complexity: the drilling, the topography and the fault line.
"I don't know what's been observed and I don't know how it's been documented," said Dan Ponti of the USGS, who cautions that such creep doesn't necessarily mean an earthquake is the cause. In 2009, a magnitude 4.7 quake struck near Lennox; but since then, only a few 2.0 quakes have occurred on that fault, according to USGS data.
To be sure, history gives residents reason to be worried about the oil field.
In the Baldwin Hills Dam disaster, federal geologists concluded that it was exploitation of the Inglewood Oil Field that caused a rupture in the earth at the top of the slope, unleashing a torrent of water. Five people died, and about 300 residences were either destroyed or badly damaged. The dry lake bed is now part of the Kenneth Hahn State Recreation Area.
In addition, PXP has had to put measures in place recently to address erosion not far from where the dam was, according to county records.
John and Alecia Smith's home in Windsor Hills may have the most visible signs of how much the land is moving. A deep ground fracture, referred to by seismologists as an echelon shear, stretches from the front of the home, across the hill and into the playground of Windsor Hills Magnet School.
Last month, the Smiths, who've lived there since 1988, had to install support beams to keep the house from collapsing. Three-inch-wide cracks travel along their walls and driveway.
Asked how much repairs have cost them so far, Alecia Smith replied, "It's staggering."
She also said that in repairing the damage in 2008, a general contractor told them the living room portion of their house is slipping, causing the fractures.
But she doesn't think it's because they sit on a fault line. In the 1994 Northridge earthquake, they only lost some pool water in the jolt, she said. And the most recent temblor, in Lennox, they didn't even feel.
"The thought that these damages are associated with fault movement is an oxymoron," she said. "The cracks are worse, the damages are escalating … and more visible. I'm concerned as a homeowner, as a resident of the community."
With 1,000 acres of scraped-away hillsides and 1,600 wells drilled, the oil field played a pivotal role in oil production in Los Angeles after going into operation in 1924. It has produced about 400 million barrels of oil from the L.A. Basin. But as the site's production slowed, new extraction methods were sought.
After a period of dormancy at the oil field, PXP in 2003 used a three-dimensional imaging process and found oil still embedded in the shale deep inside the earth. An "oil frac pack" method, a form of fracking, was used in some of the wells and at the same time a research study was conducted charting its success.
Rusch said use of the "oil frac pack" method ended shortly after that study.
By 2004 the company was drilling again, and complaints about noxious fumes and noise rose from the surrounding neighborhoods. Still, residents say, few details of PXP's operations were made public. Relations were further strained in 2006, after PXP's operations vented noxious fumes toward Culver City, causing dozens of people to be evacuated. Community leaders called on the county to implement stronger safety measures for the oil field.
The county responded by imposing a one-time moratorium on drilling while new regulations were developed in cooperation with PXP.
In 2008, community and environmental groups filed a class-action suit that challenged the adequacy of the environmental regulations. As part of a settlement reached last year, residents requested the fracking study now underway.
The California Independent Petroleum Assn., a nonprofit trade group, says fracking has been used safely in California since the 1950s.
"All wells are on the same body of regulations," said Rock Zierman, chief executive of the association. "Every well that is fractured is heavily regulated and permitted by state engineers."
State regulators, however, say companies are not required to report fracking, although PXP said it does so voluntarily.
Residents remain leery.
"We're getting warnings from all angles," said Gary Gless, whose Citizens Coalition for a Safe Community is among the groups calling for statewide ban on fracking. "We're long overdue for a quake, and fracking is just like poking a stick at it."
Standing on the wooden deck of his Windsor Hills home that overlooks the oil field, 40-year-old Dia Adilifu Fountain says he can't be sure.
"I can't just blame the oil company," he said. "When you live on the hillside, things shift, but you just don't know if 50% of it is them and 50% of it is natural, like earthquakes. It's a big mystery."