Wildfires have resulted in evacuations in some communities. Learn more.

Continuous Emission Monitoring System Code

The CEMS Code sets requirements and standards for continuous emission monitoring systems.

Explore pages in:
  • Continuous Emission Monitoring System Code


The Continuous Emission Monitoring System (CEMS) Code was first published in 1998 and revised in 2021. The CEMS Code establishes requirements for the installation, operation, maintenance and certification of continuous emission monitoring systems. These requirements will ensure effective measurement, recording and standardized reporting of specified emissions and other parameters.

In addition, the Code establishes requirements for alternative monitoring systems and for the quality assurance and quality control of continuous emission monitoring data.

For further information, read the Guidance on the 2021 CEMS Code.

Electronic reporting of continuous emission monitoring data is required by facility operating approvals and Chapter 9 of the Air Monitoring Directive.

Revised CEMS Code

The revised CEMS Code (2021) took effect January 1, 2022 and supersedes the 1998 Code.

Memo to approval holders on revised CEMS Code taking effect.

CEMS Code revision supplementary documents

Stakeholder information webinars

CEMS User Manual

The CEMS User Manual provides CEMS data providers with guidance on file formatting, coding and submission of CEMS data.

Industrial sign-off

Final verification of electronically submitted data is required; this can be done via the industrial sign-off page. Contact the CEMS user coordinator for a username and password.

CEMS mailing list

This automatic email system distributes information on updates to the CEMS Code, CEMS monitoring and electronic reporting to subscribers. Subscription to this list is open to all department staff, industry, NGOs and consultants, as well as interested members of the general public.

Use the form below to subscribe or unsubscribe from the CEMS mailing list.

All fields are required unless otherwise indicated.


Questions specific to Environmental Protection and Enhancement Act (EPEA) approvals or meeting approval CEMS requirements should be directed to the facility’s approval coordinator.

Connect with the CEMS user coordinator if you require further information concerning online reporting for your facility or are interested in training on CEMS online reporting:

Email: [email protected]

For general questions or feedback on the CEMS Code:

Email: [email protected]