Jeb Barrett remembers a couple of years ago when his fiancee noticed that three houses on one side of his Alhambra Street home in San Francisco’s Marina district were vacant. So was a house on the other side.

It was weird, he said, to be “walking home and seeing all of these empty units.”

Then one day Barrett looked outside and saw a huge conveyor belt. Workers were digging out the yard next door.

“For a number of months, they would systematically shovel out 8 feet of soil and then bring in new soil,” he said.

It wasn’t a landscaping project.

For four years, Pacific Gas and Electric Co. has been quietly buying multimillion-dollar homes in the Marina and scooping out their backyards. The utility, California’s largest, is trying to remove chemical contamination that has lurked beneath a corner of the neighborhood for more than a century, toxic waste from two long-gone fuel manufacturing plants.

PG&E so far has purchased eight homes, including one two-unit building, and is negotiating to buy a ninth. The company has resold two of the properties after swapping out the dirt.

PG&E also has removed tainted soil from the backyards of nine other nearby homes whose owners didn’t want to sell. A former gas station on Bay Street, now a construction site for a condominium development, received the same treatment.

While PG&E says it is trying to do right by the community — it is under no obligation by state or federal officials to clean up the soil — some homeowners accuse the company of downplaying the extent of the contamination. Lawyers are involved, and a lawsuit has been filed.

But few people outside the neighborhood know the extent of PG&E’s work in the Marina, because homeowners who sold their houses to the company are required to sign nondisclosure agreements agreeing to keep the terms of the sale secret.

Even some people living on the affected streets — many of them renters — say they had no idea, despite signs and flyers PG&E circulated indicating the company would be investigating and cleaning up the former gas plant sites.

Both PG&E and state regulators overseeing the work being done say the chemicals pose no danger to public health as long as they remain buried. But future redevelopment could bring them to the surface and expose the neighborhood’s residents to airborne contamination. Hence the utility’s unusual step of buying homes in an expensive San Francisco neighborhood.

All the homes that have been purchased sit atop the remains of two small plants that, starting in the late 1800s, manufactured a fuel similar to natural gas, using coal and later oil as the raw material. Both were originally owned by other companies that became part of PG&E when the utility formed in 1905. There were dozens of such plants in California, including at least two more in San Francisco.

One plant lay directly west of what is now Marina Middle School, while the other occupied land north of the Moscone Recreation Center ball fields. Together, the two plants covered about 21 acres.

Badly damaged by the 1906 earthquake, the plants were demolished to make way for the 1915 Panama-Pacific International Exposition. The residue of their operations, including such cancer-causing chemicals as benzene and naphthalene, has remained entombed under layers of dirt and pavement ever since, including beneath the middle school at Bay and Fillmore streets.

A spokeswoman for the school district did not provide a response to a request for comment.

People are routinely exposed to these chemicals in daily life, but they can be dangerous if the level of exposure is particularly high. A common scientific understanding is “the dose makes the poison,” whether that’s through skin contact or airborne contact, said Asa Bradman, an environmental health scientist and expert in exposure assessment at UC Berkeley School of Public Health.

Neither PG&E nor the state has a timetable for wrapping up the work, but the utility and other parties to a lawsuit brought over the situation will submit a report on the contamination when their joint investigation is completed.

While it may seem odd for a utility company to buy houses in a pricey San Francisco neighborhood, a PG&E spokesman said it’s just part of the effort to get rid of as much contamination as possible.

“We do it when we need to,” said Shaun Maccoun, who spoke with The Chronicle before leaving the utility for another job this month. “At PG&E, our first priority is public safety and health, and that includes our historical operations.”

The process of notifying neighbors and the cleanup itself has angered some homeowners, who say PG&E downplayed the extent of the contamination.

Dick Frisbie said that in neighborhood meetings, the company first told residents the contamination was 18 feet below the surface. But Frisbie said when he hired workers to replace a sewer line beneath his garage on Alhambra Street, they found a “wheelbarrow’s worth” of spent coal after digging down just 3 feet. Some of the pieces were bigger than a fist.

“You could just smell them by holding them up,” Frisbie said. “That changed everything with PG&E, because it turned out all the information they had given us was bogus.” He chose to sell his property to PG&E.

PG&E contends it always told residents the contamination would be within the top 10 feet of soil.

Marina residents also complain that after abatement work is done, even at a home that PG&E doesn’t buy, the state places a notice on the property’s deed. The notice requires the owner to consult with the state Department of Toxic Substances Control before doing any work that would involve extensive digging.

To homeowners, the notice is a black mark that could deter potential buyers. But to the state, it’s essential. Even though PG&E is removing contaminated soil from yards, dirt directly beneath a home’s foundation remains untouched. If a future owner wants to tear down the house and build a new one, the state wants a plan in place to remove the polluted soil.

“We think it’s very critical to managing the residual waste in place,” said Chip Gribble, the project’s manager at the toxic substances agency. “Another way would be to demo the block and dig everything up, and we all know that’s not going to happen. So what can we do that will work over time, when the people today are long gone?”

The two processing plants used to sit on what was then the bay’s shoreline, pumping out gas for homes, businesses and street lamps. The first plant opened in 1883, near the corner of Fillmore and Bay streets — the second, about a block to the east, followed in 1891.

Back to Gallery PG&E quietly clearing toxic soil from pricey Marina district 2 1 of 2 Photo: Paul Chinn, The Chronicle 2 of 2 Photo: Paul Chinn, The Chronicle



Such plants were a fixture of urban life nationwide. PG&E had 41 of them, scattered from Chico to Fresno. In the 1980s, the U.S. Environmental Protection Agency called attention to the possibility of lingering contamination from former gas plants, counting 91 in California and more than 1,500 nationwide.

PG&E then began to research its own former plants, under the guidance of the state Department of Toxic Substances Control. Although the utility’s cleanup program is voluntary, the toxic substances agency approves every step.

In San Francisco, PG&E also owned a manufactured gas plant in the Fisherman’s Wharf neighborhood, near the corner of Beach and Powell streets. That site is now completely covered by a hotel and other commercial buildings and does not require further cleanup, according to the state.

PG&E operated a fourth gas plant at the site of its former Potrero Power Plant along the city’s central waterfront, near what is now the Dogpatch neighborhood. The company is still in the process of cleaning up that site, spokeswoman Erin Garvey said.

PG&E has been testing soil and air samples at its former gas plant locations for years. Those efforts rarely lead to it buying homes, but it has happened before. In 2010, for example, the utility bought and demolished a 40-unit apartment building in Napa on a former gas plant site, bringing in relocation consultants to help the tenants move.

The utility began soil samples in the Marina the same year. PG&E purchased its first house in the neighborhood in 2012. The homeowner suggested the idea, Maccoun said.

“They didn’t want to be inconvenienced by the work and asked us if we would buy them out,” he said.

The exact terms of the buyouts are secret. One homeowner, who didn’t want to go on the record because of the nondisclosure agreement, said the company agreed to purchase the property only after the homeowner threatened to sue, claiming PG&E had intentionally deceived residents about the potential harm of the contaminants and the measures that would have to be taken to clean it up.

Participation in both the tests and the cleanup program are voluntary, and several residents have declined to give PG&E access to their backyards. If tests do find contamination and the property owners agree to let PG&E remove the tainted soil, they have the option of staying in their homes during the work, relocating temporarily at PG&E’s expense or selling to the utility.

The work can be disruptive. Many Marina homes don’t have space between them, making access to rear yards difficult.

And in such a coveted neighborhood, the homes command a hefty price.

Dan Clarke sold his eight-bedroom, 3,400-square-foot home on North Point Street to PG&E last year for $5.95 million, property records show. But Clarke had already spent years wrangling with PG&E in court over the gas plant remains, after he found two black rocks in his backyard in 2010, and their chemical composition tested positive for toxic hydrocarbons.

Clarke teamed with an association of San Francisco fishermen to sue the utility, saying the company’s tests in the neighborhood had been insufficient. The fishermen worried that contaminants in the soil could be seeping into groundwater beneath the neighborhood and trickling into the bay, possibly harming fish.

In October 2015, PG&E entered an interim settlement agreement with Clarke and the San Francisco Herring Association. Under the settlement, PG&E and the plaintiffs agreed to conduct a comprehensive investigation into the extent and nature of the manufactured gas plant contamination, including chemical analyses of the soil, air and groundwater.

The parties are required to submit a final report to state regulators at the end of the investigation, which could take another year. If they can agree on the results, the question becomes what PG&E must do to fix the problem. If they can’t agree on the results or how to fix the problem, the issue goes back before a federal judge.

Clarke, who rented his house back from PG&E after selling, declined to comment for this story.

The state has conducted groundwater tests in the neighborhood, Gribble said. But samples have only been taken beneath public rights-of-way — streets and sidewalks — due to the difficulty of drilling in an enclosed backyard.

So far, he said, tests have found some water contamination, but not a plume reaching the bay. Marina residents get their tap water from San Francisco’s Hetch Hetchy system, not groundwater.

“We’re far from done with that investigation — that’s got a ways to go,” Gribble said. “Meanwhile, we do see some contamination close to the bay, but it appears that it’s not continuous.”

Not everyone in the neighborhood is concerned about living in the vicinity of contaminated soil.

Bill and Lita Tognotti have lived on Alhambra Street for 15 years. Lita’s mother lived there before that.

Bill Tognotti said that a few years ago, workers for PG&E dug several holes about 8 feet deep on their property and took samples. Eventually, the company gave the Tognottis’ soil a clean bill of health.

Tognotti said the whole thing seemed overblown.

“I think they are trying to protect themselves from lawsuits, that’s all,” he said.

But Frisbie, his former neighbor, wasn’t taking that chance. He liked to eat tomatoes he grew in his backyard and no longer felt comfortable doing that. He also wanted to know that his grandson could play in the backyard safely. Four years ago, he and his wife moved to Laurel Heights.

“We just didn’t want to deal with living on a site that might have some contamination that might affect our health,” Frisbie said. “It’s not an inconsequential issue. Every person has to decide for his or herself what the implications are.”

Meanwhile, PG&E keeps buying houses. Barrett and his girlfriend will move out of their apartment at the end of the month. Their building’s owner is in negotiations to sell it to the utility.

Emily Green and David R. Baker are San Francisco Chronicle staff writers. Email: egreen@sfchronicle.com, dbaker@sfchronicle.com Twitter: @emilytgreen, @davidbakersf