A breakdown at Kennecott's smelter near Magna has caused an acid plant to spew an extraordinary amount of sulfuric pollution into western Salt Lake County.
"I drove into it yesterday. It was like driving into a fog. You could taste it," said Bob Dalley, director of air monitoring for the Utah Division of Air Quality.But Kennecott will likely suffer no penalties, thanks to a loophole in their air-quality permits.
The brown haze, building up since Saturday and dramatized in the late afternoon by the setting sun, was caused by a breakdown at one of Kennecott Utah Copper Corp.'s acid plants near the smelter, Dalley said.
"They were trying to bring the No. 7 acid plant back up but were having a problem."
Dalley said the emissions consisted mainly of sulfur dioxide (SO2) and sulfur trioxide (SO3).
But Dalley said he was unable to measure the sulfuric concentrations soon enough Monday evening. It was about 8:30 p.m. when he set up his measuring stations. By that time, the haze had been dispersed by canyon winds from the Oquirrh Mountains.
However, the haze appeared to be building again Tuesday. Dalley said he may try to measure the sulfur concentrations again Tuesday.
Kennecott spokesman Preston Chiaro said the No. 7 acid plant, which produces sulfuric acid as a byproduct from the main smelter operations, experienced a "mechanical failure" Saturday.
"A pump broke down," said Chiaro. "We've been struggling to get it back on line."
As the haze worsened Monday afternoon, Kennecott officials notified the state of the problem and then decided to shut the plant down. Chiaro said he is unsure when the plant will be brought back on line.
The haze Tuesday morning was caused by a similar breakdown in the No. 8 acid plant, Chiaro said. "We think we have those problems under control."
Chiaro said the breakdowns have caused an increase only in SO3, and not in SO2, which is a pollutant regulated by the U.S. Environmental Protection Agency.
SO2 can trigger respiratory problems in asthmatics and people with bronchial problems. In large concentrations, it can damage lungs. It also contributes to acid rain.
"All our monitoring stations show we haven't exceeded SO2 standards at ground-level," Chiaro said.
SO3 levels, however, have increased, exceeding the limits in Kennecott's air-quality permit.
SO3 is a solid whose main harm is a degradation of visibility.
"It's not a health problem but it's a visual impact we'd rather not have happen," Chiaro said. "We're working to correct the problem."
Though Kennecott has exceeded its allowable emissions, it will likely not be penalized because of a "breakdown" provision in its air-quality permit. Companies can escape penalties by notifying the state when they have a breakdown and then taking steps to correct the problem.