A demolition crew started removing the charred metal and broken equipment at the Husky Energy oil refinery in Superior, Wis., a key first step to reopening the facility after an explosion and fire there nearly one year ago.

But what many local residents want to know is whether work will include removing tanks of hydrofluoric acid, a highly toxic chemical that prompted a large-scale evacuation of the city as the plant burned.

For now, Husky isn't saying. A company spokesman last week said rebuilding plans are still coming together, and that the plant won't fully reopen until next year.

A recent phone survey of 1,595 Superior residents found 37 percent in favor of a hydrofluoric acid ban for the city, while 35 percent said they were unsure and 27 percent said a ban isn't necessary. The survey, by the Twin Ports Action Alliance, was the first such effort to poll local residents about the refinery's use of the chemical.

Hydrofluoric acid, which is hydrogen fluoride dissolved in water, is used in the refining process.

A worst-case scenario report on file with the Environmental Protection Agency says some 180,000 people, essentially the entire Twin Ports population, could be at risk if a fully loaded tank of hydrofluoric acid at the refinery emptied in 10 minutes or less.

The chemical causes burns and can kill. The United Steelworkers union, which represents workers at some refineries, has urged companies nationwide to stop using the chemical.

Alliance co-founder Ginger Juel said the poll showed strong support for her group's position that Superior make demands of the oil company to rebuild the plant using an alternative. She said she's doubtful Husky Energy officials will listen, however.

"They know the community does not want this chemical and they would have [made]that announcement a long time ago if they weren't going to use it," she said.

Juel has already begun looking at a new role for her group if Husky reopens the plant with the hydrofluoric acid tanks in place, saying it will push for transparency from the refinery and ask for public air monitoring stations at the facility's perimeter.

"As the refinery expands, there needs to be oversight," she said.

Even though Superior Mayor Jim Paine has also publicly called on Husky to replace the hydrofluoric acid tanks, he doesn't have many supporters among Juel's organization, who say he's not pushing hard enough for change.

"As the elected official, you have the bully pulpit, you can rally citizens to do things, and he's not willing to do that," Juel said.

Duluth Mayor Emily Larson has also asked for removal of the tanks, but Juel said a union official bragged to her that he told Mayor Larson to "shut her mouth" about hydrofluoric acid, because the position wasn't helpful to the refinery's unionized employees.

"It was pretty shocking," she said. "Politics are messy and I was never involved in politics before this."

Paine, in an interview last week, said he stands by his position on the refinery. He said the risks from hydrofluoric acid get overplayed, when a much greater risk is a conventional explosion at the refinery.

"It's just not the main safety risk," he said of hydrofluoric acid.

Paine said in an interview that even if someone was burned with hydrofluoric acid, the city's ambulance service could treat them with calcium carbonate that they carry onboard.

A representative from Gold Cross Ambulance Service, the city's provider, said the ambulances don't carry calcium carbonate, however, and Paine later walked back his statement.

"My estimation of the risk is not a professional one, nor should it be portrayed that way," he said in a follow-up e-mail.

Paine, who's running unopposed for re-election on Tuesday, said he doesn't hear about hydrofluoric acid fears from constituents when he's out door-knocking.

"It does come up; it's relatively rare," he said. "Sometimes I hear that we need to get the refinery reopened, or that we can't lose the refinery."

On an earnings call last month, Husky Energy officials said the refinery was being rebuilt "in much the same configuration as it was before," and that after it reopens, they anticipate processing more oil than in the past thanks to fewer interruptions.

The company also reported an insurance payment of approximately $350 million for property damage, business interruption, clean up and rebuilding costs.