Continuous Emissions Monitoring Systems (CEMS)

FAQ

Where can I find more information about the Commerce City Refinery?

Suncor Energy (U.S.A.) Inc. (Suncor) owns and operates three plants at two refineries, collectively referred to as the Commerce City Refinery:

  • Plant 1 is located at 5801 Brighton Boulevard, Commerce City, Colorado
  • Plant 2 is located at 5800 Brighton Boulevard, Commerce City, Colorado
  • Plant 3 is located approximately at 3875 East 56th Avenue, Commerce City, Colorado
To learn more about the Commerce City Refinery, please visit www.suncor.com/colorado.

What is a Continuous Emissions Monitoring System (CEMS)?

A CEMS is a tool that consists of equipment needed to continuously measure and record the amount or concentration of materials (such as specific gases or particles) being released from a source, such as a heater stack, into the air.

The specific components of a CEMS depend upon the parameter being monitored, the measurement principle of the CEMS, and the required units of measure. Some components are common to all systems, while others are specific to a particular monitoring technology.

To learn more about CEMS, visit the U.S. EPA Emissions Monitoring Center website.

How is meteorological data collected?

A meteorological monitoring station is located on the Suncor property. It is equipped with high-quality sensors that are used to collect and record data in near real-time.

To learn more about meteorological measurements, visit the U.S. Environmental Protection Agency's website.

What does ppm stand for?

Parts per million, or ppm, is a volume unit of measurement. It is used to measure various substances. One ppm means one part in a million parts of a total. In other words, if you have a million drops of water, one ppm means one of those drops is the substance that is being measured.

What is a stationary source?

The EPA defines a stationary source as “any building, structure, facility, or installation which emits or may emit any air pollutant.” Stationary sources must also have a fixed location, unlike mobile sources such as cars, trains, and airplanes.

Which discharge points are monitored by CEMS?

CEMS are installed on various stacks for process units and equipment within the Commerce City Refinery, such as:

  • Flares
  • Heaters
  • Boilers
  • Fluidized Catalytic Cracking Unit (FCCU)
  • Incinerators
  • H2S Analyzer Fuel Gas

What permits apply to Suncor's Continuous Emissions Monitoring Systems (CEMS)?

For more information about Suncor's air permits, please visit: Suncor Air Quality Permits.

Where can I find out more about the monitored compounds?

To learn more about measured compounds, visit U.S. EPA criteria air pollutants.

Carbon Monoxide (CO), one of six U.S. EPA criteria air pollutants, is a colorless, non-irritating, odorless, and tasteless gas. Additional information can be found on EPA's website.

Hydrogen sulfide (H2S) is a colorless gas with a strong odor of rotten eggs. Additional information can be found on ATSDR's ToxFAQs.

Nitrogen oxides (NOx), Nitrogen dioxide (NO2) and Nitrogen oxide (NO) or NOx, are a group of gases composed of nitrogen and oxygen in varying amounts. NO2, one of six U.S. EPA criteria air pollutants, is one of a group of highly reactive gases known as oxides of nitrogen or nitrogen oxides (NOx). Other nitrogen oxides include nitrous acid and nitric acid. NO2 is used as the indicator for the large group of nitrogen oxides. Additional information can be found on EPA's website.

Opacity monitors serve as a surrogate for measuring particulate matter (PM). While opacity indicates how transparent the air is, it does not quantify the actual amount of smoke or dust present. Particulate matter (PM) is very small particles in air that are less than the thickness of a human hair. Particulate matter, one of six U.S. EPA criteria air pollutants, is a mixture that can include organic chemicals, dust, soot, and metals. Additional information can be found on EPA's website.

Oxygen (O2) is an odorless and colorless gas. Oxygent amounts can affect the oxygen corrected concentration of other measured compounds.

Sulfur dioxide (SO2), one of six U.S. EPA criteria air pollutants, is a colorless gas with a burnt match smell. Additional information can be found on EPA's website.