Maybe local residents would accept a new single "commemorative" smokestack in place of the two historic chimneys that have towered over the old American Smelter and Refining Co. site for decades.

And maybe they won't.But that's one idea the City Council will consider over the next few weeks as it decides whether to demolish or refurbish the vintage smokestacks.

There is strong public sentiment for preserving the old stacks, two of the most recognizable landmarks in the Salt Lake Valley.

But the massive structures are seismically unstable in their present state, and the cost of retrofitting them to a higher seismic standard would cost an estimated $2 million to $4 million.

One proposal to build a new, seismically stable smokestack, standing 300 to 400 feet high, in place of the two old stacks is being advanced by Johansen-Thackeray and Co., a local development firm planning an $80 million-plus project on the smelter site.

John Thackeray, a general partner, said company "has always wanted to keep the stacks" if it can be done safely and economically.

"We've always been the strongest advocate of designing around them," he said. "Our drawings have always shown the stacks as staying."

The problem, Thackeray said, "is that our consultants have said they are not seismically stable as they now stand and will topple within 20 years."

Nearly all of the buildings Johansen-Thackeray plans for its 550,000-square-foot project lie in the "fall line" and would be struck by a falling stack, he noted.

The city is considering several options for the stacks, including one plan that would reinforce both structures and shorten the older 300-foot stack to about 90 feet.

Thackeray said his company is not opposed to that approach, providing the city leads out in acquiring the stacks and does not require developers to shoulder the full financial burden.

However, he said his company would consider contributing to preservation efforts as long as the stability issues are resolved.

"We've always said that if they can be preserved, we want them preserved," he said. "We like them . . . we're just concerned about their future stability.

"But the cost of retrofitting them probably is prohibitive," Thackeray added.

Preservation cost is becoming an issue for developers, Mayor Dan Snarr told the council at a study meeting last Friday.

The cost of the project is already over $9 a square foot, he said, and recent discussions have led him to believe some developers "are ready to walk" if costs go higher.

Other council members questioned that, noting the 141-acre smelter site is a golden opportunity for developers because of its size and prime location in the center of the valley.

"I don't want to see them leave," Councilman John Rush said Friday. "But I don't want to roll over for them, either."

Thackeray said what would force his company out of the project would be a decision by the city to proceed with environmental cleanup and leave the fate of the smokestacks in limbo for now.

"Nobody is willing to build anything of size or make a financial commitment if there's a possibility of the stacks falling on them," the developer said. "Nobody wants them if they're unsafe."

He also said it would be impossible to get financing or line up tenants under that kind of threat.

"Whether they stay or go, I think the issue needs to be dealt with now," Thackeray added.