WOODS CROSS — Holly Refinery and the U.S. Environmental Protection Agency have agreed to settle an alleged clean air violations case stemming from the refinery's underground storage of propane.
In the settlement announced Thursday, Dallas-based Holly Refining and Marketing Co. does not concede any violations of the Clean Air Act but will pay a civil penalty of $115,000.
An EPA inspection of the Woods Cross refinery in 2011 revealed issues with the refinery's "frozen earth storage unit" that stored propane.
Mike Astin, Holly's environmental manager at the Woods Cross refinery, said the EPA inspectors noticed a gooseneck of vents designed to collect and release small leaks of the stored propane.
"They went and detected that there were some vapors coming out of the vents, which is what they are designed to do," Astin said. "They claimed that was evidence of insufficient mechanical integrity."
Astin also said that the EPA considers propane a hazardous material because it can ignite.
The company was in the process of decommissioning the storage facility of propane because new technology was available, he said.
"We had completed our decommissioning process when they came out and ordered it closed," he said.
The EPA said the penalty was assessed under a provision of the Clean Air Act that requires risk management plans for the processing, use or storage of flammable substances and toxic chemicals.
"We contend that we are in substantial compliance with all the requirements of the act," Astin said.
The refinery also has completed its outreach to Woods Cross area residents and passersby who may have been impacted by the release of 212 barrels of fuel oil after the lid on an an above-ground storage tank ruptured.
In the Aug. 30 incident, about a mile-long area up to 50 feet wide was coated with the thick, black liquid after vapors possibly had created enough pressure to fracture the lid, Astin said.
While the lid did "exactly what it was designed to do" in the event of the accumulation of that type of pressure, Astin said, the refinery has implemented new procedures in the wake of the incident.
"We identified everything we think may have happened to cause it, and hit all of them," he said.
He also said that the Occupational Safety and Health Administration completed its review of the incident and did not recommend any action.