In what US authorities are calling the biggest enforcement action of its kind, Calgary-based Suncor Energy has been hit with more than USD$10.5 million in fines for air pollution violations at its Commerce City refinery near Denver.According to the Colorado Department of Public Health and Environment, the company must double the amount of air monitoring at the 90,000 barrel per day (bpd) facility which is located just west of the Denver International Airport.“This historic enforcement package, which includes both a penalty and required facility improvement projects, is the largest our agency has ever reached for a single facility for air pollution,” the agency’s executive director, Jill Hunsaker Ryan, said in a statement..The total penalties amount to $2.5 million. Of that amount, $1.3 million will fund projects to benefit disproportionately impacted communities through the state's environmental justice grant program — to buy EV lawn maintenance equipment — while 40% will go toward the state’s general fund.A small portion will go to the US Environmental Protection Agency as required by a previous joint EPA/Colorado enforcement action.The remaining $8 million will go to mandated improvement projects Suncor must complete to minimize “excess air pollution” from recurring due to power-related causes. .That’s because many of the violations were associated with power disruptions between July 2019 and June 2021 that caused excess releases of noxious gases such as sulfur dioxide, carbon monoxide, nitrogen oxide and hydrogen sulfide. However, there were “violations due to causes other than power disruptions,” it said.In addition, Suncor will have to double the number of monitoring stations around the perimeter of the facility under the state’s 2021 Air Toxics Act which requires it to share realtime data monitoring and issue alerts.Commerce City is one of only four refineries in the state to be required to do so. The work must be completed by December, 2026.Suncor willingly agreed to the monitoring system as part of a settlement of a lawsuit brought by eight environmental groups including Earthjustice and the Sierra Club.In a statement to the Denver Gazette, Suncor said it remains committed to improving performance and meeting regulatory requirements. It said it achieved a 26% reduction in total hours of pollution exceedance in 2023 over 2022.