Continuous Emission Monitoring, 3rd Edition

CHAPTER 9CONTINUOUS PARTICULATE MONITORING

Opacity monitors have long served in the United States as a means of tracking particulate emissions from stationary sources. A common assumption is that if an opacity limit of 20% is met, then particulate emissions standards (in mg/m³ or other) would also be met. However, mass emission requirements in state regulatory permits and federal programs have become increasingly stringent. At low particulate levels, opacity monitors are not sufficiently sensitive to either monitor the performance of particulate control equipment or to assure compliance with mass emission standards. Continuous particulate mass measurements are inherently more quantitative, enabling more precise control to be affected in plant operations. Monitoring systems that measure particulate mass concentration on a continuous basis are installed throughout Europe, where they are required for industrial boilers >50 MW and for municipal and hazardous waste incinerators, as well as other facilities.

In the United States, the 1990 Clean Air Act Amendments established requirements for enhanced monitoring, which were later translated into the Compliance Assurance Monitoring rule (CAM). CAM requires that compliance with emissions standards is always assured by either parameter monitoring or the application of particulate matter monitoring systems. Prior to 1990 particulate mass emissions were measured only periodically by conducting a manual reference test, such as the EPA isokinetic ...