Would it still be the Marina district with one less marina?

Pacific Gas and Electric Co. has proposed getting rid of one of the San Francisco neighborhood’s two namesake marinas and turning it into a shoreline, complete with a small beach, a fishing pier and tiny islands for roosting birds.

It’s the latest twist in a nearly decadelong effort to clean up contaminated soil left behind by two old fuel factories that occupied the neighborhood’s eastern end until the 1906 earthquake destroyed them. For years, PG&E has been buying up multimillion-dollar Marina homes, scooping out their backyards to get rid of the pollutants, trucking in fresh dirt, and then putting the homes back on the market.

One of the factories sat on the bay shore right next to what is now the East Harbor Marina.

The city wants to demolish the marina’s facilities, dredge out the tainted silt and then rebuild the piers, even adding room for a few more boats. But last week, PG&E proposed to the city’s Recreation and Park Commission that, instead, the marina should be phased out.

“Our proposal, which is part of our strong commitment to the environment, will cost less than a dredge and marina replacement, potentially saving the city tens of millions of dollars,” utility spokesman John Kaufman said in an email. “It would be several years before construction could begin, and in that time, we’re looking forward to lots of public input from the city and the public.”

City officials, however, have not been receptive. They view the pitch as an attempt by PG&E to avoid paying for a proper cleanup. The two fuel plants were originally owned by companies that became part of PG&E when the utility incorporated in 1905.

“PG&E is the polluter here,” John Coté, communications director for City Attorney Dennis Herrera, said in an email. “They’re responsible for the cleanup. We’ve given them every opportunity to do that, and they’ve responded by dragging their feet and trying to shirk their obligations. It’s time for them to step up.”

Boaters who use the East Harbor are equally dismissive. San Francisco has a finite number of slips, and closing the marina would eliminate 342 of them, probably forcing some of the boaters to rent spaces in other cities.

“Hopefully, this proposal will be short-lived,” said Kurt Hemmingsen, who co-owns a 26-foot boat named Josephine at the East Harbor.

The two plants date to the late 1800s, before the current neighborhood took shape.

Both made a fuel similar to natural gas, using coal and later oil as the raw material. Such manufactured gas plants were a common feature of American cities at the time, with one tally counting more than 1,500 nationwide. PG&E and its predecessor companies owned at least two others within San Francisco: one in the Fisherman’s Wharf neighborhood, the other at the former Potrero Power Plant along the city’s central waterfront.

Both Marina district plants shut down after suffering heavy damage during the 1906 quake. Their remains were demolished to make room for the 1915 Panama-Pacific International Exposition. Chemicals left over from their operations — including cancer-causing substances such as benzene and naphthalene — lay buried beneath layers of rubble, dirt and pavement as the Marina district filled up with homes.

Although largely forgotten, the gas plants left behind other traces of their existence. The bay inlet occupied by the East Harbor Marina is still known as Gashouse Cove.

So long as the chemicals stay buried, they don’t pose a health risk, PG&E representatives and state officials say. But the utility has been testing for their presence and replacing backyards to prevent future development from accidentally unearthing them.

The neighborhood’s waterfront features two marinas, both built in 1963. The city has been working to update them since 2002. Renovations to the West Harbor Marina, the larger of the two, were completed in 2013.

At the East Harbor, the city wants to demolish the existing docks, dredge the silt and then rebuild the facility, upping the number of boat slips to at least 350. A 2015 project document from the Recreation and Park Department estimated the construction cost at $6.7 million, although that figure did not include demolition or dredging. A department spokeswoman said the city did not yet have a firm estimate for dredging costs.

PG&E argues that its plan would cause less disruption to nearby residents and businesses, while avoiding the need to truck large amounts of silt to landfills. It would also provide more habitat for birds and fish. A PG&E representative pitched the idea to the park commission at its Jan. 18 meeting.

“The proposal we delivered was an early step,” Kaufman said. “For next steps, we’re looking forward to meeting with Rec and Park to discuss these options.”

A spokeswoman for the department, while not rejecting the proposal outright, said any decisions about the harbor would be made by the city and the community, not PG&E.

“Long-term policy discussions about recreational uses on our public lands should be driven by park constituents, policy makers and appropriate regulatory agencies,” spokeswoman Connie Chan said in an email. “PG&E’s only role in any such debate is to ensure it fulfills its own environmental obligations.”

Although nearly surrounded by water, San Francisco has a limited number of marinas for boaters, including facilities in Fisherman’s Wharf and South Beach.

The two Marina district harbors have become home to a long tradition of Wednesday night boat races from spring through fall, Hemmingsen said. A typical race, he said, gathers 150 to 200 people and perhaps 35 to 40 boats. Were many of the boaters forced to relocate their boats, to South Beach or even Sausalito, they would have a hard time participating.

“I am not kidding when I tell you it’s sometimes the second or third generation of sailors coming together every Wednesday night,” said Hemmingsen, 47, an account executive at a Silicon Valley tech firm. “And that tradition would be in jeopardy.”

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF