AP/Wide World Officials from East Liverpool, Ohio, wait for Vice-President Al Gore's procession to pass in February in Cleveland

While the city may not scare the presidential candidate, the hazardous waste plant, visible through the trees in Estell's backyard, might.

Estell, husband Bob, and their five children have lived about 900 feet from the incinerator since it went online in 1993. On the other side of her home is an elementary school with 400 kids. Son Alex, a fourth grader, studies there.

They and other local residents believe the waste incinerator is a health threat and that emissions from the plant are harmful. And they blame Al Gore for not shutting it down.

A company representative of Von Roll WTI, an Ohio subsidiary of Swiss waste technologies company Von Roll, Inc., headquartered in Zurich, says the plant is so clean that one of its workers could safely do an eight-hour shift inside the smokestack without a respirator.

In 1992, before the incinerator had fired-up its ovens, then vice-presidential candidate Gore made the controversial plant a campaign issue.

"And I'll tell you this, a Clinton-Gore administration is going to give you an environmental presidency to deal with these problems. We'll be on your side for a change," Gore told Weirton, West Virginia, voters in July 1992 on a bus tour.

"I thought, 'Oh, thank you, God!' This is going to be an answer to our prayers. He's gonna come in here. They're gonna do the right thing. They're gonna shut this plant down," Estell said.

But instead, the plant went into full operation during the first year of the Clinton-Gore administration. In 1994, Congress's investigative arm, the General Accounting Office (GAO), reported the plant would destroy 60,000 tons of hazardous waste annually, including carbon tetrachloride, monochlorobenzene, and 1,2,4 trichlorobenzene, all industrial solvents, and heavy metals arsenic, cadmium, lead, mercury, and chromium.

"It's emblematic of a constant failure on the part of the Clinton-Gore administration and noticeable because of Gore's image to really protect the public from dioxins and other persistent toxic chemicals," Joe DiGangi, a researcher for Greenpeace's Toxics Campaign, told Fox News.

At the time, environmentalists felt betrayed and a series of protests, some organized by Greenpeace, began at the plant and in other locations.

Terri Swearingen, 43, has been arrested nine times protesting the incinerator, including inside and outside the White House, at Ohio's Environmental Protection Agency (EPA), at the U.S. EPA and the Swiss Embassy in Washington, D.C..

Swearingen lives just two miles from East Liverpool and has made it her mission to remind Gore about his promise.

"We have to hound him, to hold him accountable and I think that's our job as a citizen of this country," Swearingen, a former nurse and homemaker, said.

During an April campaign stop in Vidalia, Ohio, Gore was asked about the incinerator again. "Most of the options that were available to us were taken away from us by a last-minute decision on the part of the Bush-Quayle administration to grant them that permit," Gore said in response to an audience member's question asking him whether the plant would shut down.

Gore notes the EPA is investigating the permit process, but the vice president says there's little anyone can do now that the plant is legally running.

And defending Gore is the incinerator company, saying Gore never promised to block the plant from opening.

"His promise was to investigate the permitting of this facility. That was done by U.S. EPA and Ohio EPA," Fred Sigg, general manager and vice president of Von Roll, Ohio, Inc., told Fox News.

In this presidential election year, the issue has split environmental groups. Some are breaking ranks, returning to the Gore camp.

"I think there is not only a gap, there's a chasm between George W. Bush and Al Gore and Al Gore has stood firmly on the side of moving in the right direction," Carl Pope, executive director of the Sierra Club, said.

Even incinerator opponents living near the plant agree Gore is the "greener" candidate. Does that mean they'll lighten-up on Gore? No chance.

"If we can't trust him on this issue in East Liverpool, Ohio, how can somebody trust him in, you know, Iowa or Idaho or Nebraska or wherever else he's made promises to the people?" Swearingen asked.

"Whatever it takes is what we'll do," Estell said. She and Swearingen say they will continue to hound the vice president until the incinerator is shut down.

—Fox News' Sharon Kehnemui contributed to this report