Agitation Builds Over Man-Made Quakes

At Allen Clay’s house in this mountain hamlet of Lake County, earthquakes aren’t just a distant worry. They are an unsettling fact of daily life.

Clay points to his kitchen counter as proof. The counter has become slightly bent, causing water to run down one side. His outdoor walkway has slanted in places, and the foundation of his tidy bungalow shows small cracks -- all the result, he believes, of temblors.

“If you shake something every day, something’s going to happen,” Clay said.

Anderson Springs, population 350, has become a California seismic curiosity.

Even though it’s not near any active fault lines, the town has recorded a quake an average of 1 1/2 times a day for seven years. In the surrounding 50-square-mile Geysers region about 90 miles north of San Francisco, 3,000 temblors occurred in 2002 alone -- making it one of the most seismically active regions in the United States.

There is agreement by all sides that the temblors are man-made, caused not by the clashing of tectonic plates but by two dozen geothermal plants operating as close as two miles from Anderson Springs.

Opened 40 years ago, the plants feed off Lake and Sonoma counties’ famous geothermal field, which years ago drew visitors from around the world to bathe in the mineral springs. The plants generate 1 million megawatts of power, making them the largest geothermal producer in the world.

In what was once an area of little seismic activity, quakes began increasing when the plants opened. But the temblors have become even more common since the plants’ main operator, Calpine, began injecting millions of gallons of wastewater daily underground to spur the creation of steam used to produce the electricity.

The vast majority of the quakes are small -- usually magnitude 1 or 2, which can barely be felt. But every few months, a stronger one occurs. There have been nine greater than magnitude 4.0 in the area over the last two decades, the largest being a 4.6.

A growing number of residents have joined to demand that something be done. They also want the plant operators, who acknowledge the quakes’ link to the energy production, to pay the residents for what they assert is property damage from the quakes that has slowly built up.

The movement has prompted debate by residents and seismologists about how serious the problem is and whether homeowners are owed compensation.

Anderson Springs is one of several mountain communities formed to take advantage of the region’s hot springs. A century ago, the area boasted resorts and health spas where visitors came to bathe in the “therapeutic” waters. But the resorts eventually closed or burned down, and some of the tiny communities fell on hard times.

Many saw the opening of the geothermal plants as a new way to harness the geysers that would boost the town. Indeed, a dozen Anderson Springs residents work at the plants, which employ a total of 425 workers.

But these days, the earthquakes have become a consuming topic in town.

Two local environmental organizations have helped organize concerned residents, and one conducted several surveys that polled about half the town’s inhabitants. Eighty-seven percent of those polled last summer agreed with the statement “Earthquakes are becoming a public nuisance at Anderson Springs.”

“I’m going to have a structural engineer look at my house,” said Jackie Felber, pointing to hairline cracks in her floors and displacements in the siding.

The mother of three has lived in Anderson Springs for 18 years. She first noticed a surge in quakes in 1998 -- just after the wastewater injections were stepped up.

“We’ve always had quakes up here, but the quakes were milder,” she said. “It would shake a little bit. These quakes are so strong that it seems like a truck is hitting your place.”

After six years, she said, she has grown tired of being awakened by the temblors.

Resident Connie Dethlefson said that with some of the quakes “it feels as if there’s an explosion under the house.”

After she pointed to cracks and displacements, and told of house guests fleeing her home in fear when quakes struck, Dethlefson was asked why, if the shaking was so bad, she had bottles of wine standing on the edges of shelves above the hard floors.

“I’m not going to screw everything down just because” the geothermal operators “are making my life miserable,” she responded.

Dethlefson, Felber and Clay are among the residents seeking compensation.

The firms -- Calpine Corp. and the Northern California Power Agency -- don’t rule it out. In fact, they suggest they would prefer to pay something to show goodwill, as long as they do not have to admit formal liability and open themselves up to endless payments.

J.L. “Bill” Smith of the power agency said compensation could be called “a community assistance fund,” although he added that he believed the quakes had caused no appreciable damage. He said he didn’t see how they could have, because they had not damaged his company’s offices at the plants.

Last fall, Smith and Calpine’s Mitch Stark, both scientists, joined with officials from the U.S. Geological Survey and Lawrence Berkeley National Laboratory to issue a white paper in which they agreed that the geothermal plants were the cause of most of the earthquakes.

“Scientists who have studied Geysers seismicity universally agree that most of these earthquakes have been induced by geothermal field operations,” the paper stated.

But the statement stopped short of concluding that the injections of wastewater were directly related to specific quakes or to a rise in their number. The injections have been found to be necessary to keep the production of steam from diminishing over the years, and the plant operators hope that, with the injections, the geothermal field will continue to support electricity production for decades to come.

The Geysers field is not the only place where large numbers of small quakes have followed injections. Such temblors have been recorded at the Coso field near Little Lake on the eastern side of the Sierra Nevada, and at the south end of the Salton Sea in the Imperial Valley, where there are other, smaller geothermal developments.

Scientists are not sure precisely what causes the quakes, although Caltech seismologist Egill Hauksson said there was a general theory that the injection of water into the fields opens up subterranean cracks and makes them more susceptible to slip, generating the quakes.

In the Coso field, scientists have found that water is working its way up from deep underground. There, the quakes in recent years have been smaller than those in Anderson Springs.

In the Lake County town, the prevalence of man-made earthquakes poses questions of legal liability that are new even in a state known as Earthquake Country.

The quakes have become “pretty annoying to these people at Anderson Springs,” said David Oppenheimer, a U.S. Geological Survey scientist who has studied the Geysers area. “It’s kind of like hearing a dog bark constantly.... There’s a nuisance factor, and there may be a damage factor.”

Some residents have threatened to file lawsuits if they are not compensated. One is Jeffrey Gospe, head of the Anderson Springs Community Alliance, who said his family purchased property in the community eight years ago without having been told about the geothermal plants’ earthquakes.

The outcome of that action is uncertain, some experts suggest, because it could prove difficult to establish legally that such relatively small quakes caused specific damage. Visits to several homeowners pointed up some of the difficulties of such a case.

Mary Jadiker, for instance, gave a detailed account of how a magnitude-4.4 quake was felt Feb. 18 at her home outside Cobb, a town about three miles north of Anderson Springs.

“I was standing up, typing on my computer, when the ground motion started,” she said. “There wasn’t a sound, but it shook from all directions. Things fell off shelves everywhere, wineglasses, items from my kitchen pantry. I have been told since that the newest injection point of the wastewaters was just a mile away from us.”

But Jadiker said she had taken no pictures of the damage.

In any case, Anderson Springs residents are far from united about whether the power companies owe them money because of the quakes.

“I guess I understand they’re trying to get some protection for the homeowners,” said tavern owner Bruce Lightfoot. “So I should be for that. But the quakes have been happening for such a long time now, I would think this could be a tough case to prove.”

A woman listening to him, Rose Sauer, was more skeptical. As a Californian, she said, she finds earthquakes normal.

“They’re all over California.”