SALT LAKE CITY -- Utah regulators are promising to deliver a set of plans to curb air pollution by July but said Wednesday that the task won't be completed easily.
Officials told a powerful state board their plans will achieve as little as 80 percent of the emissions reductions required by the federal government for urban areas of northern Utah.
Regulators don't know how to close the gap.
Tailpipe emissions account for more than half of Utah's pollution problem, but regulators have shown no interest in mandating cleaner gasoline or more efficient cars.
Utah already is moving to reduce industrial emissions, but regulators say industries represent a small piece of the pollution puzzle.
The problem could be the nation's most difficult to solve, regulators said. They blamed a combination of mountain geography and weather systems that trap emissions in valleys for days or weeks at a time, allowing no escape.
One plan requires Utah to reduce emissions in the Salt Lake region by 227 tons a day. Regulators said Wednesday that they were 22 tons short of reaching that goal.
In Utah County, the gap is wider. Regulators are 10 tons shy of reducing emissions by 52 tons a day.
"It's incredible how much reduction we have to get" to comply with federal air standards, said David McNeill of the Utah Division of Air Quality.
The Utah Air Quality Board has already acted to ban the sale of wood-burning boilers for home heating. It's moving against aerosol-powered consumer products like hairspray by requiring more environmentally friendly propellants. The board also is imposing new emissions controls on hamburger joints that use conveyor-driven flame broilers to cook their beef.
"It's going to crimp everyone's lifestyle, and people aren't noticing that yet," McNeill said.