LIVERMORE -- The debate over where future Livermore BART stations should go appears to be headed toward a communitywide slugfest, making the outcome of the decades-long dream to extend rail service past Dublin anything but certain.

A petition aimed at stopping BART from coming through downtown Livermore was filed with the city clerk Tuesday. The Alameda County Registrar has 30 days to certify it or stop it in its tracks.

A total of 8,354 signatures -- about 500 more than leaders of the "Keep BART on 580" petition estimated they had -- were collected, according to a rough count done in the city offices, said City Clerk Susan Neer. Only about 4,700 valid signatures of registered Livermore voters are needed to qualify the measure for an election ballot.

If the petition is certified, council members will have three options, said City Attorney John Pomidor. They can adopt it, which would force them to renounce their endorsement of BART's decision to place future BART stations in downtown Livermore and at Vasco Road; they can put the petition to a citywide vote; or they can order a report on what the outcome of adopting such an initiative might be, Pomidor said.

The numbers are encouraging, Linda Jeffery Sailors, a former Dublin mayor involved with the petition, said Friday.

"Our volunteers know that this is just step one and that we must now focus on the November election," she said.

But, during an hourlong interview Friday, Livermore Vice Mayor John Marchand called the petitioners "disingenuous," attacking the veracity of claims made on their website, www.keepbarton580.org, and to the public.

"What has been the most frustrating for me is that I am bound by the truth, but a number of the people circulating this petition are not," Marchand said.

The petition is being manned by 175 volunteers -- a group including past Livermore mayors, a past Alameda County supervisor, a past BART director and others who fought to bring BART to Dublin/Pleasanton. They say an Interstate 580 alignment with a first-phase station at Isabel Avenue and a second-phase station at Greenville Road makes the most sense.

Petitioners say that route would have the lowest price tag -- the cost of a line ending at Isabel would be just over $1 billion, versus about $3.8 billion for a downtown route -- and the least impact on existing homes, while sidestepping the need for scores of high-density homes downtown.

They point to 1,500 more housing units around the downtown and Vasco station sites that would be needed to meet federal funding requirements for the project, for housing located within a half-mile radius of stations. That's on top of 1,841 units already in the downtown station area and several thousand more planned but not yet built, they say.

Marchand blasted petitioners' statements that only "minor adjustments to the urban growth boundary" would be needed to meet federal funding requirements for housing within a half-mile radius of stations at Isabel Ave/I-580 and Greenville Road/I-580.

Because the Airport Protection Area prohibits development at I-580 and Isabel, if no more units can be added near Dublin BART, then the more than 6,400 housing units needed to qualify the project for funding would have to be built around Greenville.

The U.S. Fish & Wildlife Service called the area a "critical wildlife corridor," and building there would require a citywide vote to move the urban growth boundary.

In 2005, nearly three-quarters of Livermore voters opposed an initiative by Pardee Homes to break the urban growth boundary and build 2,500 homes in North Livermore.

They also overwhelmingly re-elected Mayor Marshall Kamena, who opposed breaking the urban growth boundary.

"The petitioners keep saying (Livermore) never actually voted on the urban growth boundary," Marchand said. "To me, the referendum for the urban growth boundary was the 2005 election."

Petitioners also have said the downtown/Vasco plan would result in a train platform being built across from Junction Avenue School -- a misleading claim because the station would be all underground, Marchand said.

Because of the Metropolitan Transportation Commission's requirements for transit oriented development, a downtown/Vasco alignment is the only one that would be fundable, he and many others insist.

Sailors refuted that claim Friday, saying, "We believe that all obstacles can be overcome and the council can do (a freeway alignment) if they want to."