Suncor released sulfur dioxide spikes, state says

Commerce City refinery had equipment failure

BY MICHAEL BOOTH THE COLORADO SUN

e Suncor re nery in Commerce City sent potentially dangerous spikes of sulfur dioxide into the surrounding neighborhood early April 12 after an equipment failure, though the state health department’s notice didn’t go out until that evening.

Sulfur dioxide detected from Suncor leapt to 155 parts per billion and 186 parts per billion, while the EPA’s National Ambient Air Quality Standards are 75 parts per billion. But to reach an o cial exceedance, the sulfur dioxide levels must be that high for over an hour. By 9 a.m. Wednesday, a state news release said, the levels had “dropped signi cantly.” e state release at 6:23 p.m. said the spike readings “were veri ed a short time ago.” Despite the drop in the monitored sulfur dioxide levels, the Colorado Department of Public Health and Environment urged families in the future to limit outdoor exercise, keep windows closed and consider an air puri er. e state release said that early

“ e short exposures to sulfur dioxide that occurred earlier could have exacerbated asthma and made breathing di cult, especially during exercise or physical activity,” the health department said.

Wednesday, “the Suncor facility reported that #2 Sulfur Recovery Unit and associated Tail Gas Unit in Plant 1 brie y tripped o ine due to a level indicator issue, resulting in: excess sulfur dioxide from the Tail Gas Unit Incinerator (H-25); aring of acid gas (gas with elevated hydrogen sul de) in the Plant 1 Flare; elevated hydrogen sul de in the Plant 1 fuel gas system.”

Neighbors and environmental advocacy groups have been expanding independent monitoring of emissions from Suncor, and amplifying calls for a complete shutdown or at least far tougher state regulation of the re nery. e only re nery in Colorado, Suncor supplies a large portion of vehicle gasoline for the Denver metro area and airplane fuel for Denver International Airport.

A re in December damaged equipment at Suncor and forced a weekslong shutdown of the complex, followed by a series of emissions noti cations to neighbors as Suncor worked to bring the facility back online. e shutdown also signi cantly raised gas prices for Colorado drivers during the winter.

Multiple monitors around Suncor check for dangerous emissions, including some run by a neighborhood nonpro t Cultivando through a state environmental justice project. Cultivando released a report from Boulder atmospheric scientist Detlev Helmig in March warning of exactly what happened in mid-April: Short-term emissions from Suncor