The operators of the Davis County waste-to-energy facility are pouring too much sulfur dioxide and carbon monoxide into the air, according to the Bureau of Air Quality.

The bureau mailed a notice of violation last week to Davis Energy Systems Co., a private firm that runs the facility, or "burn plant," under contract for the Davis County Solid Waste Management and Energy Recovery District.It's the second air-quality violation the state has issued the company this year.

According to the latest notice, the burn plant's two incinerators violated emissions standards for sulfur dioxide numerous times between Oct. 1 and Dec 31.

Marvin Maxell, bureau director of compliance, said emissions limits were violated on 28 days during October, 17 days in November and 17 days in December.

Maxell said, however, that "to their credit," the length of actual time the plant was violating the standards got smaller in December, with a few exceptions.

State air-quality officials examined monitoring records and also discovered that carbon monoxide levels exceeded the standards during the same three months.

When asked of the consequences of the emissions, Maxell said, "I don't think anyone's died, or it has done a lot of environmental damage, although the carbon monoxide occurred during a period we were experiencing an inversion."

However, Maxell said, the violations are "serious in the sense that we don't want to set a precedent. . . . We don't want to make the same mistakes."

At issue, he said, are the limits that were agreed upon by the state and Davis Energy Systems when the company applied for its permit in the mid-1980s. The burn plant was - and still is - the only plant of its kind in the state.

"I expect that they're going to contest this," Maxell said. "Their attorneys have already called the attorney general's office and ripped us up."

Also in question are the plant's air-pollution control methods.

"Let's just say it's not working to our satisfaction," Maxell said.

One method consists of a lime-injection process to reduce acid. The other method maintains temperatures for proper combustion. Those measures were permitted after the company convinced state officials that it couldn't afford wet scrubbers, which cost between $3 million and $5 million.

Maxell said the lime-injection system has had several problems and may have contributed to hydrochloric acid violations that were cited earlier this year.

In that case, a state inspector found that the smokestack was emitting 41 pounds of acid per hour on Dec. 27. The legal limit is 16 pounds per hour.

Maxell said that violation is being disputed and may lead to a new permit process in which the company will seek different standards.

"The whole issue is not resolved at this time. We're asking them to do a one-year study on how they can limit the emission."

David R. Spahn, acting plant manager for Davis Energy Systems, did not return phone calls to the Deseret News.

LeGrand Bitter, director of the energy district, refused to comment because the district and the company are suing each other over a number of issues, one of which is the contract, which requires the company to meet all environmental regulations.