Wyoming’s most-fined refinery for safety violations is facing another round of penalties, this time stemming from a formal complaint and three August incidents at the facility, according to a report in the Casper Star-Tribune.

The Wyoming Occupational Safety and Health Administration has proposed a $259,950 fine against the Sinclair Oil-owned Sinclair Wyoming Refinery. The fine would be the largest levied against a refinery in Wyoming in the past five years.

Combined with a proposed $215,000 in total fines following two fires in 2012, the Sinclair Oil refinery has been hit with nearly half a million dollars in proposed fines in two years.

Six-figure fines are unusual for state OSHA plan enforcement programs.

The most recent violations include repeat violations for failure to ensure proper employee training and a lack of up-to-date diagrams for some piping at the facility. New violations include failure to ensure all equipment was built to design specifications, failure to cover open floor holes and lack of a fire extinguisher at an assigned location.

The repeat violations account for $165,000 of the proposed penalties.

According to a statement from Sinclair, the company plans to meet with Wyoming OSHA, a division of the Wyoming Department of Workforce Services, to discuss the fines.

“Sinclair takes these citations seriously and is working with great urgency to make refinery-wide safety enhancements,” said Sinclair in an emailed statement.

The refinery has received more citations and fines than any other in the state in the past five years, according to a Star-Tribune analysis of federal OSHA data.

The company references three August incidents in the same release but does not specify what happened. Representatives of the company confirmed two different fires and an emergency shutdown procedure that month, according to Star-Tribune reports. No one was injured in any of the events.

OSHA staff found a total of 48 violations items at an inspection the following month that triggered this round of citations. Inspectors deemed 37 violations serious and six as repeat violations.

The latest fines proposed by OSHA are part of a series of mishaps and fine-heavy inspections at the Sinclair refinery. Two fires in May 2012 that burned six employees — three severely — led to two OSHA inspections which earned the facility roughly $215,000 in proposed fines.

The fines are considered informal until Sinclair responds. The company has 15 days upon receipt of the violations to appeal or request a conference with OSHA. Fines and violations could be reduced if the company responds.

Sinclair and OSHA have each been working in recent months to make Wyoming refineries safer. Sinclair and other refiners in the state have banded together to form the Wyoming Refinery Safety Alliance, a private-public partnership which is regularly assisted by OSHA. The company has also reassigned a vice president to work specifically in safety and has created and planned several new safety-oriented positions.