Air quality and the Suncor refinery


Please note: Technical and legal documents are only available in English. If you would like to request assistance in Spanish, please email cdphe_apcd_outreach@state.co.us and indicate “Suncor refinery translation request” as the subject of your message.



The Suncor refinery is located on Brighton Boulevard near Sand Creek in Commerce City. It is the only petroleum refinery in Colorado. Suncor manufactures gasoline, jet fuel, diesel fuels, and asphalt.

Several Colorado Department of Public Health and Environment teams assist with regulating Suncor and sharing information with nearby communities. This webpage aims to provide an overview of the CDPHE Air Pollution Control Division’s oversight of Suncor.

Other CDPHE resources relevant to Suncor include:

Suncor’s impact on air quality

Suncor’s operations create pollution that can impact air quality. Some of the air pollutants Suncor produces include: 

  • Nitrogen oxides and volatile organic compounds. These can create ground-level ozone pollution when mixed with sunlight and heat.
  • Particulate matter. This is made up of very small pieces of dust, dirt, smoke, and other materials. 
  • Air toxics. Some of the most common ones in petroleum products include benzene, toluene, ethylbenzene, and xylenes.
  • Sulfur dioxide.
  • Hydrogen sulfide.
  • Carbon monoxide. 

Investigating and addressing air quality violations

The CDPHE Air Pollution Control Division ensures Suncor follows all applicable state and federal requirements to protect air quality. The division provides continuous oversight of Suncor and completes a comprehensive annual inspection each year. The division uses the legal enforcement process to investigate potential air quality violations, confirm if a violation happened, and address violations. These processes typically end with an enforcement package. Enforcement packages may include penalties, requirements to correct a violation, or other requirements to encourage better performance in the future.


The division finalized a $10.5 million enforcement package with Suncor in February 2024. The package required Suncor to make improvements at the refinery to reduce air pollution and benefit the community. This included improvements to Suncor’s power reliability.

The division also finalized a $9 million enforcement package with Suncor in March 2020. The package required Suncor to hire an independent contractor to investigate the root cause of the air quality violations and take action to address those causes. This action led to Suncor improving its Fluidized Catalytic Cracking Units. The division has made documents about the root cause investigation available to the public. The package also included a voluntary Supplementary Environmental Project to benefit the community near Suncor.

Enforcing air quality requirements is a legal process. It takes time and requires due diligence. The time needed to resolve an enforcement action varies depending on the case's complexity.

Violations are often intermittent, meaning they are typically not ongoing throughout an enforcement action. The enforcement process does not address emergencies. In the rare occurrence of an emergency, the division can take steps to address an issue immediately in coordination with state and local emergency services.


Air quality permits

Suncor must maintain Title V operating permits because state and federal regulations consider it a “major source” of air pollution. This is based on Suncor’s emissions levels. “Title V” refers to a section of the federal Clean Air Act.


Suncor is legally considered one facility but has two Title V permits because the plants were originally under different ownership. Regulations allow for a facility to have more than one air quality permit.

The CDPHE Air Pollution Control Division issued Suncor’s latest Plant 2 Title V permit with an effective date of Sept. 1, 2022. When the U.S. EPA reviewed Suncor’s Plant 2 Title V permit, it also sent the division a letter with some environmental recommendations for consideration. The division responded to the U.S. EPA’s letter in November 2022.

The division issued Suncor’s latest Plants 1 and 3 Title V permit with an effective date of July 9. 2024. For the first time ever, CDPHE conducted a disparate impact analysis as part of the Title V permitting process for Suncor’s Plants 1 and 3. This was to ensure that the permitting action did not cause further harm to the nearby Commerce City and North Denver communities.

Suncor may also submit other permit applications or notices to the division. For example, Suncor occasionally decides to make changes to its equipment. Depending on the modification, the division may require Suncor to submit a permit or an Air Pollutant Emissions Notice


Air monitoring near Suncor

The CDPHE Air Pollution Control Division closely monitors and collects data from Suncor’s emission points. The division conducts its own monitoring and references other available monitors in the area.

The division has five permanent air monitoring sites near Suncor. Hourly data from each site is available on the division’s air quality reports web page. The five permanent sites include:

  • Adams Birch Street site, located at 7275 Birch Street.
  • Welby site, located at 3174 E. 78th Ave.
  • CAMP site, located at 2015 Broadway.
  • La Casa site, located at 4587 Navajo St.
  • I-25 Globeville site, located at 4905 Acoma St.

Suncor is also subject to air monitoring requirements under the 2021 Colorado Regulate Air Toxics Act. That state law directed the division to do more air monitoring in the community and required Suncor to establish a fenceline air monitoring system around the facility’s perimeter.

In early 2022, the division considered feedback on Suncor's draft fenceline monitoring plan and posted records for all comments received.

In January 2023, Suncor started operating a partial fenceline air monitoring system. Suncor posts data from the system on its fenceline air monitoring website. The division finalized Suncor’s fenceline air monitoring plan through a legal action completed in February 2024. Suncor must have the whole system operational by the end of 2024.

In January 2023, the division began community monitoring within a 3-mile radius of Suncor and other covered facilities. The division regularly deploys the Community Air Toxics (CAT) mobile monitoring van to the area.

Suncor is also subject to air monitoring requirements under the 2022 Colorado Public Protections from Toxic Air Contaminants Act. In 2023, the division began operating a stationary air toxics monitoring station at the Adams Birch Street location.


Community notifications

As part of the March 2020 enforcement package, the division required Suncor to work with the community on an improved notification system. Through those required engagement sessions, Suncor developed a three-tiered system for informing the community of any incidents. Suncor implemented the system in September 2021. The system includes:

  • Tier one: An apparent emergency in which the community may need to react to protect itself, such as by sheltering in place. This type of event would result in a reverse 911 notice to the community.
  • Tier two: An event that may be alarming to the community but is not an apparent emergency. This type of event would be when the community can see, hear, or smell something out of the ordinary at the time when Suncor sends a notification. Suncor sends notifications through an optional notification system for this type of event.
  • Tier three: An event resulting in excess emissions or other incidents that Suncor must report to the division or the U.S. EPA. This type of event might not result in the community seeing, hearing, or smelling anything unusual. Suncor must post information about these events in monthly summary reports on its website.

The 2021 Colorado Regulate Air Toxics Act further enhanced Suncor’s community notification requirements. The division again further enhanced community notification requirements through the same legal action completed in February 2024 related to fenceline air monitoring mentioned earlier in this web page.


Suncor performance analysis

In 2021, the CDPHE Air Pollution Control Division requested an analysis of Suncor and other refineries nationwide that operate under similar requirements. The division requested the analysis to better understand Suncor’s performance and identify areas for improvement. The U.S. EPA agreed to do the analysis and completed it in June 2023. The data includes the number of air quality violations and the operating and maintenance practices.


Press releases and records

The CDPHE Air Pollution Control Division stores publicly available documents in an online records database called “OnBase.” Visit the division’s records web page to learn more. The page includes a section dedicated to Suncor’s permit applications, incident reports, and other documents.

The following links generate search results for Suncor’s relevant records in OnBase.



2021 - 2020



2019 - 2018 - 2017




2016 - 2015




Contact us

Questions? Email the CDPHE Air Pollution Control Division at cdphe.commentsapcd@state.co.us.