Safety and environment information

Suncor Energy (U.S.A.) Inc. cares deeply about the communities in which we operate throughout Colorado, particularly those surrounding the Commerce City Refinery.

Aerial view of the Commerce City Refinery in Commerce City, Colorado.

Public notifications

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Community air monitoring

We developed an enhanced air monitoring program for the Commerce City and North Denver communities. Visit to see air quality information in near real time and data reports.

Visit the CCND Air website

We are committed to producing the high-quality fuels and other products critical to driving Colorado’s economy safely and in an environmentally conscious manner. This commitment is shared across our workforce of more than 500 committed and talented Colorado residents, including more than 250 union employees.

We monitor the air and water and are dedicated to continuing to provide information for the community on these issues. More information on these processes can be found in the sections below.


In response to community feedback, we are starting a new community air monitoring program.

Explore community air monitoring

Current community air monitoring

Currently, for refinery shutdowns, other planned events, and unplanned incidents, Suncor monitors the air in the communities near the Commerce City Refinery using highly specialized monitors capable of detecting oxygen (O2), carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2), flammable/combustible vapors (LEL), and volatile organic compounds (VOCs).

Monitoring is based on wind speed and direction and is conducted by Suncor personnel who drive through the community and stop periodically to take readings and assess conditions. We prioritize schools, parks, medical buildings, and event centers, and compare our data to national standards from:

  • Occupational Safety and Health Administration (OSHA)
  • American Industrial Hygiene Association (AIHA)
  • American Conference of Government Industrial Hygienists (ACGIH)

We also monitor the Colorado Department of Public Health and Environment (CDPHE)’s community air monitoring station results that are accessible to the public through their website. If our air monitoring data shows levels that exceed applicable standards, we will activate our Emergency Operations Center (EOC) and coordinate our efforts with local fire and police.

Air emissions regulations

We have multiple reporting requirements regarding air emissions. Depending upon the specific rule, regulation, or permit limit, the refinery may be required to notify CDPHE, Environmental Protection Agency (EPA), National Response Center (NRC), Local Emergency Planning Committee (LEPC), or the State Emergency Response Commission (SERC). Reporting is required whenever a permit limit is exceeded or whenever a rule requires notification to a certain agency, such as exceeding a reportable quantity in 24 hours. Some notifications are made right away, while others are typically reported the following business day. Some permit limits have very short-term parameters, such as a six-minute average, and some could be more long-term, such as an annual emissions limit. Examples of our most common air reporting requirements are:

  • Opacity exceedances from Fluidized Catalytic Cracking units (FCCs): over 20% opacity in a 6-minute period
  • Smoke from flares: 5 minutes total in a 2-hour period
  • Carbon monoxide (CO) limits: unit or equipment specific limits
  • Nitrogen oxide (NO) limits: annual tons per year per individual unit or equipment
  • Hydrogen sulfide (H2S), in flare/fuel gas header: 162 ppm average in a 3-hour period
  • Excess sulfur dioxide (SO2) emissions above permit limits: 500 pounds in a 24-hour period

In addition to these required notifications, there are times that we notify CDPHE as a courtesy, even when no limits are exceeded. An example would be flaring, smoke, or some other visible activity that did not exceed a permit limit. In comparison to 2019, as of the end of November 2020, our total number of permit limit exceedances is down approximately 56%, the duration of our permit limit exceedances is down approximately 42%, and our tons of sulfur dioxide (SO2) emissions are down approximately 48%.

Hydrogen cyanide (HCN)

When we process crude oil into gasoline using specific equipment at the refinery (known as a fluidized catalytic cracker, or FCC), one of the by-products is hydrogen cyanide (HCN). This is true at many fuel refineries that use processing equipment like ours. In coordination with CDPHE, Suncor Energy (U.S.A.) Inc. will be conducting HCN monitoring at the refinery while CDPHE conducts community monitoring. Based on the monitoring data, we will determine with CDPHE the most appropriate path forward with respect to HCN.

Title V operating permits

Suncor Energy (U.S.A) Inc. operates within two separate Title V operating permits - one that covers the refinery’s Plants 1 and 3, and one that covers Plant 2. The Title V permit for Plants 1 and 3 was last revised on February 22, 2018, and the Title V permit for Plant 2 was last revised on June 15, 2009. Between formal renewal periods, the Title V permits are subject to periodic modifications. To learn more about Title V permits, visit CDPHE's website.

We have submitted a renewal application for the Plant 2 Title V permit. The renewal process is governed by CDPHE’s Air Pollution Control Division (APCD), which will set the 30-day public notice period for the application. Full information relating to the application will be available at that time. For more information on public notices, visit CDPHE’s website.


Water permit

Suncor Energy (U.S.A.) Inc. is authorized to discharge wastewater and storm water to Sand Creek in accordance with the requirements of discharge permits issued by the Water Quality Control Division (WQCD) under the Colorado Discharge Permit System (CDPS). Permits are typically renewed on a five-year cycle. Effluent limits and permit requirements can and do change during each renewal cycle.


Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that include PFOA, PFOS, and many other chemicals. PFAS chemicals have been manufactured and used in a variety of industries throughout the world, including as a key chemical ingredient used in firefighting foams at refineries, petrochemical plants, airports, and Department of Defense facilities.

At the request of CDPHE, Suncor Energy (U.S.A.) Inc. has conducted testing for PFOS/PFOA at the Commerce City Refinery which confirms the presence of these chemicals in the groundwater below the refinery. Recent testing also indicates the presence of PFOS/PFOA in treated groundwater that is discharged from our outfall to Sand Creek - this water is discharged in accordance with a permit issued by CDPHE.

We believe the presence of PFOS/PFOA at the Commerce City Refinery is due to the historical use of Class B firefighting foam, typical of an industrial site like ours. Suncor is working closely with CDPHE, including testing of additional locations near the refinery. The resulting data indicates PFOS/PFOA compounds are present in varying levels of concentration in Suncor groundwater samples, as well as in nearby surface waters (Sand Creek and South Platte River) both upstream and downstream of the Commerce City Refinery. We are closely following the actions being taken by the EPA and CDPHE to address the presence of PFOS/PFOA.

In response to the Colorado Firefighting Foams Control Act, we have replaced our inventory of older firefighting foam with a new foam that complies with the U.S. EPA’s PFOA Stewardship Program-2015 Requirements. We are working through our plan to safely dispose of the older foam through a third-party vendor.

The Suncor Emergency Response Team does not currently use any firefighting foam containing PFAS chemicals during our on-site firefighting training events. If any firefighting foam is needed in an actual emergency, Suncor will make all reasonable attempts to keep the material on site through containment or retention to prevent the migration to surface, ground, or storm water.

Sand Creek

Sand Creek is a body of water located near the Commerce City Refinery. We actively monitor and protect Sand Creek by using a boundary wall along the water line and ground water monitoring wells.

In the summer of 2021, the refinery is replacing the existing underground barrier wall and building a second, parallel barrier wall. These enhancements will improve conditions at the boundaries of the refinery.

Wastewater treatment plant

Many industrial processes, including petroleum refining, use water. Our Commerce City Refinery uses both city water and collected groundwater for steam production and cooling, as well as to wash out the natural contaminants in crude oil, like salts and minerals, to prevent corrosion in our processing units.

Much of this water is recycled for reuse at our facility, and the remaining portion is treated and discharged to Sand Creek, under a permit issued by CDPHE. In September 2012, stricter compliance criteria were set on the refinery discharge water, effective in January 2018. To meet the new criteria, the Commerce City Refinery commissioned a $65 million USD upgrade to our existing wastewater treatment facility. The upgrade was completed in December 2017 and leverages a unique technology called membrane ultrafiltration to treat and filter the water. Our facility is one of the first in North America to use this technology in treating refinery wastewater streams.

Membrane ultrafiltration removes particles from wastewater down to approximately 0.08 microns in size, which is about 1,000 times smaller than the diameter of a human hair. Ongoing and future construction phases will enable us to strive to continuously improve our environmental performance as well as meet increasingly tightening regulations related to wastewater treatment and discharge. At peak construction, the project employed 180 craftspeople working around the clock. The construction of the project created business for local construction companies, fabricator shops, and local suppliers of concrete, steel, electrical and control, as well as room and board for travelers.

Alarm information

The community surrounding the Commerce City Refinery may hear various types of alarms. The alarm system is tested every day at 12 p.m. and is used any time an incident occurs as part of our emergency management procedures. Alarm protocols are in place to alert operations teams to assess the situation and take the appropriate actions to address it. These protocols align with our best practices regarding escalating quickly, intervening safely, and de-escalating as required. Any alarms heard by the community are meant for the refinery personnel and do not require action from the public in all cases. As part of our new Refinery Notifications system, subscribers may also get a notification when an alarm sounds. Click here to learn more about this system.

In the case of an emergency that requires immediate action by the community, we will continue to use the Integrated Public Alert and Warning System (IPAWS) through Adams County to notify the community surrounding the refinery.

There are four types of alarms you may hear as a community member near the refinery. The alarms will state the incident type and location:


The refinery routinely investigates the causes of various operational events that occur at the facility and compiles reports based on the findings of the investigation. View available reports below:

Reportable event summaries

The refinery complies with many air, water, and hazardous materials-related reporting requirements, including reports required by our permits. 

For detailed information on our permits, see the Air and Water sections above.

We submit reports to the Colorado Department of Public Health and Environment at different times depending on applicable requirements, but you can now view a monthly summary of what we have submitted in each category:

To view individual reports and other information that has been published on the Colorado Department of Health and Environment's website, visit: