The Suncor Energy refinery in Commerce City during its December shutdown polluted Sand Creek with excessive levels of benzene, a chemical naturally found in crude oil and gasoline that can cause blood diseases, cancer and menstrual irregularities through long-term exposure.
Suncor filed a notice with the Colorado Department of Public Health and Environment to notify the state of the benzene discharge into Sand Creek, reporting levels that were 40% to 80% above permitted allowances, according to a letter sent Friday to the department’s Water Quality Protection Section.
During a Dec. 24 fire at Suncor’s Plant 1, which refines oil into gasoline and other fuels, benzene containing hydrocarbon entered the refinery’s stormwater system, according to the letter.
Testing found benzene levels at 7 micrograms per liter on Jan. 4 and 9 micrograms per liter on Jan. 5, the letter said. The refinery’s permit allows a daily maximum of 5 micrograms per liter to be discharged into Sand Creek. The excess benzene was first reported by Colorado Public Radio.
After discovering elevated benzene concentrations in the creek next to its refinery, Suncor isolated the affected water so it could be treated to reduce the chemical to below permitted levels, the letter said. Testing on Jan. 6 showed benzene concentrations at 1 microgram per liter.
Loa Esquilin Garcia, a Suncor spokeswoman, said Tuesday that she would not be able to answer The Denver Post’s questions about the spill, including what the company is doing to prevent it from happening again, until the end of business on Wednesday.
Sand Creek flows into the South Platte River, which is a source of drinking water in Colorado. After Suncor notified the state about the benzene levels, officials began alerting downstream users as a precaution, according to an email chain included in the original Jan. 6 report on the spill.
The Suncor refinery suffered a major malfunction on the night of Dec. 21 when a bitter cold front swept across the Front Range. The company reported that subzero weather tripped its hydrogen plant, a critical piece of the refining infrastructure, and caused problems to occur across the facility.
In the days after the shutdown, the company reported two fires on its property. Two workers were injured in the Dec. 24 fire, and no injuries were reported after a Dec. 27 fire. The federal Occupational Health and Safety Administration has opened an investigation into the Dec. 24 fire.
After the Dec. 24 fire, Suncor officials decided to shut down refinery operations to repair equipment damaged during the deep freeze and to perform maintenance across the facility. The company has said it will bring its three plants back online gradually with the goal of being fully operational by the end of March.
Since the Dec. 21 malfunction, the company has filed multiple reports with the state health department to notify regulators that it has exceeded its permit allowances for air pollution. The benzene spill is the only notification of a water permit violation.
Most recently, on Thursday, Suncor reported that a unit used in making gasoline exceeded opacity, or smoke, limits by 63%, according to a filing with the health department.
And on Jan. 11, Suncor submitted a malfunction report to the state’s Air Pollution Control Division that its sulfur dioxide emissions at the Plant 1 sulfur plant incinerator exceeded permitted levels. The company reported sulfur dioxide levels reaching 256 parts per million, above the 250 parts per million limit.
Many environmentalists had hoped Suncor’s shutdown would give the community a chance to see what air and water quality would look like without the plant in operation. But with ongoing repairs to equipment, the company has said people will see and hear work happening, including flares coming from the refinery’s smokestacks.
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Updated 5:50 p.m. Jan. 27, 2023 This story has been updated to add a statement from Suncor Energy.
