Stack and CEMS Performance Testing

The DEEP Source Emissions Monitoring (SEM) group oversees the stack testing and CEMS performance testing programs. Emission tests are performed in the State of Connecticut for the purposes of: (1) determining actual pollutant emissions from stationary sources of air pollution, (2) determining compliance with air pollution limits for both state and delegated federal standards, and (3) ensuring air pollutant Continuous Emissions Monitoring (CEM) systems pass quarterly testing audits including relative accuracy test audits (RATA) to ensure that the monitoring systems are accurate and operating within state and federal requirements. All emissions testing must be conducted in accordance with procedures prescribed by or acceptable to the Department of Energy and Environmental Protection (DEEP) as set forth in the revised Source Emissions Monitoring Test Guidelines Version 2.0 (Test Guidelines 2.0).

Test Guidelines

SEM revised the Test Guidelines on April 30, 2019 as part of a LEAN initiative to launch its new compliance emissions testing and Relative Accuracy Test Audit operational procedures in order to:

  • ensure standardization and uniformity of stack testing conducted to demonstrate compliance with state and federal emissions standards (NSPS, NESHAP, MACT) where delegated to the DEEP;
  • pinpoint information that needs to be reported nationally into the national Compliance and Emissions Data Reporting Interface (CEDRI) on a timely basis;
  • ensure that the DEEP's Intent to Test (ITT) protocols identify the correct test requirements and test methods to ensure that the regulatory requirements of each applicable test program will be met; and to clarify the different requirements of both DEEP and EPA when both oversee emissions testing.

Note: All emissions testing must be conducted in accordance with procedures prescribed by or acceptable to DEEP as set forth in the revised Test Guidelines Version 2.0.

How to Initiate a Stack Test or RATA

To initiate a stack test or RATA program a source must:

  1. Secure the services of an accredited stack test contracting firm. 
  2. Submit a completed ITT form and protocol (where required) within the timelines as specified in the Test Guidelines. 
  3. Provide access to the test program to the DEEP auditor. 
  4. Submit a report of the test results with a completed Compliance Certification Form and all supporting documents within deadline as specified in the Test Guidelines. 

All documents and test reports should be submitted electronically to

Changes to Stack Test and RATA Programs

Changes to the stack test and RATA programs include the requirement to use one of three new ITT Forms which replace the former ITT Form (dated 01/24/12) and one of the new test report Compliance Certification Forms.

Standard and Non-Standard Test Programs

A test program must be identified as either a Standard Test (ST) or Non-Standard Test (NST) as prescribed in the Test Guidelines to ensure that all the requisite information is provided in advance of a test. Both ST and NST require one of the completed ITT Forms however, a NST program requires additional documents (protocol and other supporting documents).

Standard Test Protocol

45-days advance notice prior to testing

  • No longer requires submission of a protocol with the ITT Form

Non-Standard Test Protocol

60-days advance notice prior to testing

  • Requires attachments
  • Test method deviation justification (if applicable)
  • Protocol

Note: In lieu of using the new ITT and Compliance Certification Forms, SEM will accept protocols and test reports submitted using EPA's Electronic Reporting Tool which can be uploaded to the SEM's FTP (file transfer protocol) site.

Frequently Asked Questions

New forms will be required starting July 1, 2019.

Submit inquiries to:

All completed forms, test reports, supporting documents are required to be submitted to the SEM Group at:

Documents that are too large to e-mail or protocols and test reports in the ERT format may be uploaded using the file transfer protocol (FTP) website:

To obtain the username and password to the FTP site, submit an email request to

If you have questions regarding submittal of documents using the FTP site, contact the SEM Group via phone at (860) 424-4152 or email at


Content Last Updated: July 29, 2021