Stacks, air quality

Stack Testing & Continuous Emissions Monitoring Systems (CEMS)

Emissions testing is the process of determining the mass or concentration of emissions being generated by a process. Emissions testing is typically performed on a stack or vent. Generally, there are two reasons for conducting emissions testing or emissions monitoring. By Lindsey Kroos, ALL4.
 
Emissions testing is the process of determining the mass or concentration of emissions being generated by a process. Emissions testing is typically performed on a stack or vent. Generally, there are two reasons for conducting emissions testing or emissions monitoring. First, testing or monitoring may be performed for engineering purposes to assess how a particular process is operating. Second, and more common, emissions testing and monitoring are performed to assess compliance with regulatory limits or to establish regulatory limits. The most common methods of emissions testing or monitoring incorporate manual methods of collecting an integrated sample over a period of time, or the use of automated monitors that collect “real time” measurements of emissions levels over a set period of time.

An emissions testing and monitoring program needs to be carefully planned and implemented. Some of the key considerations are the purpose of testing, planning and coordination, the protocol for testing procedures, the plan for logistics and execution, and record-keeping and reporting.

The original approach for measuring emissions from stacks and vents consisted of manual methods developed by U.S. EPA. Manual methods, which are still an integral part of emissions testing and monitoring, consist of a probe that is inserted into a stack or vent; a filter and impinger section, which is designed to collect particulate and gaseous emissions; and a pump and flow monitoring and controlling equipment. The filter media and the impinger section are analyzed in the lab for the amount and type of emissions.

Automated or continuous emissions testing procedures are a very common approach for determining the level of emissions in a stack or vent. The U.S. EPA has developed several methods for assessing the real-time concentration levels for different gaseous pollutants. The typical automated sampling system includes a probe that is inserted into the stack or vent; a heated sample line that brings a stream of vent or stack gas to the continuous monitor; and a continuous monitor that use various methods of detection to determine gas concentration levels.

To learn more about the why and how of continuous monitoring, as well as initial certification and ongoing quality assurance requirements, data validation, data averaging, and preventative and corrective maintenance procedures, visit: https://www.all4inc.com/training/aq101/.

About the Author

Lindsey Kroos is a Technical Manager at ALL4 with 15 years of experience in air quality consulting, including permitting and compliance for clients in various industries such as pulp and paper, waste combustion, and manufacturing. Lindsey is passionate about learning and sharing air quality technical knowledge, and is the primary instructor for ALL4’s AQ101 training program. ALL4 is an environmental consulting company and currently employs over 85 professionals with a diverse background of experience, including the consulting, industry, and regulatory arenas.


ALL4’s Air Quality 101 (AQ101) Training is a 12-session, webinar-based course covering the Clean Air Act and its various regulatory programs.  Originally designed to educate environmental consultants as they joined the ALL4 team, it was requested by clients to further their understanding of compliance and permitting at their facilities.  ALL4 has trained environmental professionals of the regulated community throughout the country and expanded their knowledge of regulatory programs that impact industrial operations.
 

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