An incinerator that burns hazardous material from Utah and around the West is facing more than $500,000 in penalties for environmental violations.

The Utah Department of Environmental Quality issued 48 violations against Clean Harbors Aragonite LLC in Utah's West Desert for problems in 2007-08.

Ten of the violations had a "major" potential for harm, including several fires at the facility. It is Utah's only large-scale incinerator for hazardous materials.

In a deal scheduled to be formally adopted next month, the DEQ is proposing that the company face $519,697 in penalties. That includes a cash payment of $153,000 and requirements to do several projects meant to benefit the environment and resolve ongoing problems at the site.

The proposal is part of a settlement negotiated between the state and the company.

"This is the largest one I've ever worked on," said Don Verbica, a section manager and 25-year veteran in the state's Division of Solid and Hazardous Waste.

Each year, the facility processes millions of pounds of hazardous materials, from contaminated soils and pesticides to industrial solvents and out-of-date pharmaceuticals.

Since opening about 70 miles west of Salt Lake City, the incinerator has changed hands several times and had trouble with regulators.

Prior to the latest round of violations, public records show the DEQ had issued more than $644,000 in penalties since the incinerator opened in 1991. That includes $323,666 in fines for 89 violations since Clean Harbors took over in 2002, according to DEQ records.

The business is among the most regulated in the country, and it's not uncommon for hazardous-waste operations to have periodic violations, said Phillip Retallick, Clean Harbor's senior vice president of regulatory affairs.

"We think we're not atypical, but it's our company philosophy to strive toward zero defects," he said.

The latest violations came at a time of high turnover at the operation, Retallick said.

New businesses that moved into Tooele County several years ago hired away many of the plant's employees, he said. That left the company scrambling to get new employees up to speed on the complicated regulations and procedures associated with handling and burning hazardous materials, Retallick said.

Since then, new managers have been brought in, employment has stabilized, and the company has spent nearly a million dollars to boost salaries, benefits, recruiting and improvements at the site, he said.

"I think that combination has really helped us improve," Retallick said.

State officials recognize the complexity of the operation and the importance of having somewhere to incinerate hazardous waste, Verbica said. The company has been cooperative and made investments in improvements, he said.

"They've taken it very seriously," Verbica said.

Based in Norwell, Mass., Clean Harbors calls itself the largest hazardous-waste disposal company in North America. The Aragonite facility is one of four incineration operations it runs in the United States.

Many of the violations in Utah involved failures to keep track of shipments, violations of storage regulations and problems with documentation.

Among the more serious were several fires at the site, lapses in monitoring for radioactive waste, a lack of monitors checking for dangerous vapors and recorded results for tests that were never conducted.

The proposed penalty has been adjusted downward by 40 percent because of the current economic crisis and a "significant reduction" in the amount of waste coming into the plant, according to the draft order.

Aside from the cash payment, the company would be required to build storage facilities for certain kinds of chemicals and install roof-mounted monitors intended to detect potentially explosive contaminants.

The public has until Monday to comment on the proposal. The state's Solid and Hazardous Waste Control Board is scheduled to take up the proposal at its Oct. 8 meeting.